Ergonomic surgical instruments

[0001] This application is a continuation of U.S. Patent Application Ser. No. 12/245,158, filed Oct. 3, 2008 and entitled, “Ergonomic Surgical Instruments,” now U.S. Pat. No. 8,623,027, which is hereby incorporated by reference in its entirety and which claims the benefit under Title 35, U.S. Code §119(e), of U.S. Patent Provisional Application Ser. No. 60/997,901, filed Oct. 5, 2007 and entitled “Ergonomic Ultrasonic Surgical Instruments,” which is hereby incorporated by reference in its entirety.

[0002] Ultrasonic surgical instruments, including both hollow core and solid core instruments, are used for the safe and effective treatment of many medical conditions. Ultrasonic surgical instruments, and particularly solid core ultrasonic surgical instruments, are advantageous because they may be used to cut and/or coagulate tissue using energy in the form of mechanical vibrations transmitted to a surgical end effector at ultrasonic frequencies. Ultrasonic vibrations, when transmitted to tissue at suitable energy levels and using a suitable end effector, may be used to cut, dissect, coagulate, elevate or separate tissue. Ultrasonic surgical instruments utilizing solid core technology are particularly advantageous because of the amount of ultrasonic energy that may be transmitted from the ultrasonic transducer, through an ultrasonic transmission waveguide, to the surgical end effector. Such instruments may be used for open procedures or minimally invasive procedures, such as endoscopic or laparoscopic procedures, wherein the end effector is passed through a trocar to reach the surgical site.

[0003] Activating or exciting the end effector (e.g., cutting blade, ball coagulator) of such instruments at ultrasonic frequencies induces longitudinal vibratory movement that generates localized heat within adjacent tissue, facilitating both cutting and coagulating. Because of the nature of ultrasonic surgical instruments, a particular ultrasonically actuated end effector may be designed to perform numerous functions, including, for example, cutting and coagulating.

[0004] Ultrasonic vibration is induced in the surgical end effector by electrically exciting a transducer, for example. The transducer may be constructed of one or more piezoelectric or magnetostrictive elements in the instrument hand piece. Vibrations generated by the transducer section are transmitted to the surgical end effector via an ultrasonic waveguide extending from the transducer section to the surgical end effector. The waveguides and end effectors are designed to resonate at the same frequency as the transducer. When an end effector is attached to a transducer the overall system frequency may be the same frequency as the transducer itself. The transducer and the end effector may be designed to resonate at two different frequencies and when joined or coupled may resonate at a third frequency. The zero-to-peak amplitude of the longitudinal ultrasonic vibration at the tip, d, of the end effector behaves as a simple sinusoid at the resonant frequency as given by:
d=A sin(ωt)
where: ω=the radian frequency which equals 2π times the cyclic frequency, f; and
A=the zero-to-peak amplitude.
The longitudinal excursion is defined as the peak-to-peak (p-t-p) amplitude, which is just twice the amplitude of the sine wave or 2A.

[0005] Solid core ultrasonic surgical instruments may be divided into two types, single element end effector devices and multiple-element end effectors. Single element end effector devices include a variety of blade types such as ball, hooked, curved, and coagulating shears. Single-element end effector instruments have limited ability to apply blade-to-tissue pressure when the tissue is soft and loosely supported. Substantial pressure may be necessary to effectively couple ultrasonic energy to the tissue. The inability of a single-element end effector to grasp the tissue results in a further inability to fully coapt tissue surfaces while applying ultrasonic energy, leading to less-than-desired hemostasis and tissue joining. Multiple-element end effectors include a clamping mechanism comprising a clamp arm that works in conjunction with the vibrating blade to form a jaw like structure. Ultrasonic clamping coagulators provide an improved ultrasonic surgical instrument for cutting/coagulating tissue, particularly loose and unsupported tissue. The clamping mechanism presses the tissue against the vibrating ultrasonic blade and applies a compressive or biasing force against the tissue to achieve faster cutting and hemostasis (e.g., coagulation) of the tissue with less attenuation of blade motion.

[0006] As an alternative to open surgical procedures, many modern surgeons use endoscopes and endoscopic instruments to remotely access organs through smaller, puncture-like incisions. As a direct result thereof, patients tend to benefit from less scarring and reduced healing time. Endoscopic instruments are inserted into the patient through a cannula, or port, which has been made with a trocar. Typical sizes for cannulas range from three millimeters to twelve millimeters. Smaller cannulas are usually preferred. However, the smaller cannulas in turn present additional challenges in the design of the endoscopic instruments that fit through the smaller cannulas. Many endoscopic surgical procedures require cutting or ligating blood vessels or vascular tissue as well as grasping, cutting, dissecting, coagulating, elevating, manipulating, and/or separating tissue.

[0007] For the purposes herein, “coagulation” is defined as a process of desiccating tissue wherein the tissue cells are ruptured and dried. “Vessel sealing” or “tissue sealing” is defined as the process of liquefying the collagen in the tissue so that it reforms into a fused mass. Coagulation of small vessels is sufficient to permanently close them, while larger vessels need to be sealed to assure permanent closure. Tissue welding is a technique for closing wounds and vessels and is applied in many surgical specialties. Tissue welding is a technique for closing wounds by creating a hemostatic seal in the wounds or vessels as well as creating strong anastomoses in the tissue. Ultrasonic surgical instruments may be employed to achieve hemostasis with minimal lateral thermal damage to the tissue. The hemostasis or anastomoses occurs through the transfer of mechanical energy to the tissue. Internal cellular friction breaks hydrogen bonds resulting in protein denaturization. As the proteins are denatured at temperatures below 100° C., a sticky coagulum forms and seals small vessels. Anastomoses occurs when the effects are prolonged. Thus, the ultrasonic energy in the vibrating blade may be employed to create hemostatic seals in vessels and adjacent tissues in wounds and to create strong anastomoses in tissue. Ultrasonic vibrating single or multiple end effectors, either alone or in combination with clamping mechanisms, produce adequate mechanical energy to seal vessels regardless of the temperature of the end effector and/or the tissue. To create strong anastomoses of the tissue, the temperature of the end effector and the tissue should be maintained below approximately 50° C. to allow for the creation of a coagulum to seal the tissues together without desiccating the tissues.

[0008] In the design of medical instruments, several factors may be applied to assess the viability of the ergonomics of a particular design. One factor of ergonomics is comfort. Comfort may be characterized by the ability to manipulate and control the device without undue muscle strain, pressure points, or other harmful ergonomic effects. Comfort is created from properly sized features located to fit the anatomy of the user, and adequate distribution of force against the user's body. The ability to use an instrument over an extended period without fatigue, pain, or loss of precision is a measure of comfort. Another factor of ergonomics is the ability to use an instrument over an extended time period without fatigue, pain, or loss of precision is a measure of comfort. Aside from comfort, one objective factor is the ability to control the working end of the device with the degree of control needed to accomplish the surgical task with ease. The extent that this control may be achieved emanates first from the inherent stability of the instrument in the hand of the user, and second from the ability to perform finer motions in order to manipulate the specific instrument controls. Design efforts balance the ability to achieve overall stability in the hand while facilitating appropriate access and mobility to utilize the fine controls. The stability of the surgical instrument in the hand may be accomplished via a variety of grips. Common grips include ring handles, in-line scissors, and pistol configurations, among others. Pistol grips generally provide points of fixation on the hand:

[0009] (1) A point between the thumb and index finger resting in the web of the joint;

[0010] (2) A grasping force between the thumb and index finger; and

[0011] (3) A gripping force between the fingers and the palm when activating a trigger, power switch, knob, lever, or other feature.

[0012] Due to the inherent spatial considerations of the surgical cavity, surgeons often have difficulty performing traditional surgical methods using endoscopic instruments inserted into the patient through a cannula. The spatial limitations, coupled with the multi-function capability of many endoscopic instruments, particularly laparoscopic ultrasonic surgical instruments, create ergonomic challenges for the surgeon to easily access and operate the multiple functions and controls of the instrument. Many ultrasonic surgical instruments with multiple-element end effectors require a high force of the jaws of the clamping mechanism, which in turn requires higher input forces at the handle/trigger. This creates challenges in providing a comfortable handle/trigger interface for the user. Just as important is to enable the surgeon to finely control the opening motion of the jaws to facilitate fine dissection without creating fatigue or pressure points on the surgeon's hands. Activating electrical power switches on the ultrasonic instrument housing also presents a challenge. A surgeon needs to easily access any of the switches at any point while also avoiding inadvertent or unintentional activation at any time. Other functions that a surgeon may need to perform include rotating the shaft, or selecting power levels. In addition, the user should be able to operate any of these functions without looking, allowing them to focus entirely on the monitor view during a laparoscopic procedure. In addition, it may be desirable for the user not to have to reposition their grip in order to operate any of these key functions the power switches, and be able to easily manipulate the clamp force or power levels while opening the jaws of the clamping mechanism of the end effector.

[0013] Other ergonomic challenges presented by conventional laparoscopic ultrasonic surgical instruments include the ability of the user to easily access and operate multiple functions, sometimes simultaneously. Typically the index finger is used to operate a rotation knob located at the distal end of the device handle to rotate the shaft. However, controlling the power buttons/switches also employs the use of the index finger, creating an inherent challenge for locating the rotation knob and the switches on the housing such that they both may be reached by the index finger. Ultrasonic devices include multiple controls such as shaft rotation, power settings, and trigger closure that must be accessible in various hand positions and for many hand sizes.

[0014] Traditional laparoscopic ultrasonic surgical instruments usually have a rotation control knob located at the distal end of the instrument that can be accessed with the index finger to rotate the shaft. However, controlling the power buttons/switches also employs the use of the index finger, creating an inherent challenge for locating the rotation knob and the switches on the housing such that they both may be reached by the index finger. The finger tip rotation control often may be difficult to reach for a surgeon with small hands especially when the instrument is oriented in positions at extreme angles or orientations that may be necessary to position the tip of the instrument in proximity to the anatomy to be treated.

[0015] With respect to hand size, it has long been a challenge to create laparoscopic ultrasonic surgical instruments with a handle design in terms of size, shape, and location of control interfaces that is “ideal” for everyone. The very large disparity of anthropometrics from small females to large males traditionally creates challenges for users at the extreme ends of the spectrum. Although instruments having various different sized handles to accommodate the disparity in hand sizes have been considered, purchasers generally desire to carry fewer inventories, and thus multiple variations have not been accepted. In addition, there is always the risk that a certain sized handle may not be available to a particular doctor at a particular hospital.

[0016] The multi-function capability of many ultrasonic surgical instruments, particularly laparoscopic ultrasonic surgical instruments, create ergonomic challenges in the ability of the user to comfortably access and operate the multiple functions and controls of the instrument. This include, for example, the ability to comfortably actuate the jaws of the clamping mechanism and activate the hand control buttons/switches, sometimes simultaneously. The user should be able to control the opening motion of the end effectors to facilitate spreading dissection. Laparoscopic handle interface designs traditionally incorporate a “scissor” type ring to allow for this outward motion, using outward movement of the thumb to oppose the “anchored” fingers. However, this does not provide optimal control of the tip. Some conventional ultrasonic surgical instruments may comprise a pistol grip that incorporates a trigger that is pushed outward with the index and middle fingers of the user while maintaining a grip on the handle stock, however, this may create fatigue and hand strain. This outward motion, however, may be necessary when doing fine dissection during a laparoscopic procedure. The pistol grip style handle provides comfort, ease, and stability to the surgeon. The conventional pistol grip style handle may not be optimum, however, for dissection, where many surgeons prefer a scissor grip style design instead.

[0017] Accordingly, there is a need for an ergonomic handle assembly for an ultrasonic surgical instrument that provides the ability of the user to comfortably access and operate multiple functions. In addition, there is a need for a handle assembly for an ultrasonic surgical instrument that enables a user to comfortably actuate the jaws of the clamping mechanism and activate the hand control buttons/switches. There is also a need to optimize the handle assemblies in terms of ergonomic comfort, stability, and controllability for a large range of hand sizes.

[0018] In one embodiment, a surgical instrument comprising a trigger is configured to be actuated by a proximally directed force and by a distally directed force. The trigger may comprise a proximal trigger portion having a first length and a distal trigger hook comprising a distal portion having a second length. The second length may be less than the first length. The distal trigger hook may be coupled to the proximal trigger portion.

[0109] Before explaining the various embodiments in detail, it should be noted that the embodiments are not limited in its application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative embodiments may be implemented or incorporated in other embodiments, variations and modifications, and may be practiced or carried out in various ways. For example, the surgical instruments, handle assemblies, handle adapters, and other components associated therewith disclosed below are illustrative only and not meant to limit the scope or application thereof. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative embodiments for the convenience of the reader and are not to limit the scope thereof.

[0110] It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping a handle portion of the handle assembly of an ultrasonic surgical instrument. Thus, the end effector is distal with respect to the more proximal handle portion. It will be further appreciated that, for convenience and clarity, spatial terms such as “top” and “bottom” also are used herein with respect to the clinician gripping the hand portion. However, surgical instruments may be used in many orientations and positions, and these terms are not intended to be limiting and absolute. The term “right” refers to the right side of the instrument from the perspective of a user looking toward the “front” of the instrument from the distal end towards the proximal end. The term “left” refers to the left side of the instrument from the perspective of a user looking toward the “front” of the instrument from the distal end toward the proximal end. The term “rear” refers to the user rear of the instrument from the perspective of the user looking from the proximal end towards the distal end of the instrument.

[0111] The various embodiments relate, in general, to ultrasonic surgical instruments with improved multi-function capabilities and ergonomic control features for use in laparoscopic and/or traditional open surgical procedures. The ergonomic features described with respect to the various embodiments of the ultrasonic surgical instruments enhance the ability of the user to easily and comfortably access and operate multiple functions of the instruments located in multiple places on the instruments, in order to maximize the level of precision and control the surgeon has when performing a clinical task.

[0112] Various embodiments of ultrasonic surgical instruments described herein comprise comfortable and ergonomic control features associated with the handle and trigger interfaces for the user. This may alleviate stresses and fatigue in applications that require very high clamping forces between the jaws of the end effector. The ergonomic features provide ease of control of the opening motion of the jaws to facilitate various surgical procedures, such as fine dissection. Electrical power switches are provided to activate an ultrasonic transducer assembly. These switches may be hand operated such that the user may easily access one or more of the power switches at any point while avoiding inadvertent or unintentional activation at any time. The switches include features that enable to user to select the proper switch without looking. Similarly, rotational control of the shaft is easily accessed. This allows the user to focus entirely on the monitor view during a laparoscopic procedure, for example. The switches may be activated without the user repositioning the grip on the instrument. The user can easily control power application while simultaneously opening the jaws of the end effector. In one embodiment, the power switches may be implemented as a MIN/MAX rocker-style or “toggle” style switch. In a forward position, the MIN/MAX toggle switch provides an easily accessible contact surface projection for power activation without repositioning of the hand grip, making it suitable to maintain control and keep attention focused on the surgical site (e.g., a monitor in a laparoscopic procedure).

[0113] There has been a long sought need to provide surgical instrument handles in terms of size, shape, and location of control interfaces that suitably accommodate the large disparity of anthropometrics from small females to large males and of various ethnicities. Users at these extreme ends of the spectrum traditionally have difficulty using conventionally sized instrument handles as intended. Thus, various embodiments provide a handle assembly for a surgical instrument that suitably accommodates a substantially larger range of hand sizes. Various embodiments provide more optimally designed ergonomic features for comfortably controlling the surgical instrument during use. Various embodiments provide multiple ergonomic hand adaptors are provided.

[0114] Certain embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying-drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting embodiments and that the scope of the various embodiments is defined solely by the claims. The features illustrated or described in connection with one embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the claims.

[0115] FIGS. 1-25 illustrate one embodiment of an ultrasonic surgical instrument suitable for endoscopic or traditional open surgical procedures. In the embodiment illustrated in FIGS. 1-25, a surgical instrument comprises improved multi-functional capabilities and ergonomic features for use in laparoscopic and/or traditional open surgical procedures. The ergonomic features of the surgical instrument enhance the ability of the user to easily access and operate the multiple functions and controls of the surgical instrument. The ergonomic features of the multi-functional ultrasonic surgical instrument enable the user to easily access and operate the multiple functions and controls of the instrument.

[0116] In one embodiment, the instrument comprises a handle assembly comprising a rotation knob located at a distal end of the handle assembly. The user may use a finger to operate the distal rotation knob. The rotation knob is mechanically engaged to an ultrasonic transmission waveguide shaft, which is coupled to the clamping mechanism of the end effector assembly. Thus, the user may employ a finger to rotate the distal rotation knob to suitably orient the jaws of the clamping mechanism of the end effector assembly.

[0117] In one embodiment, the handle assembly comprises a rocker switch to control the power for energizing the ultrasonic transducer. In one embodiment, the rocker switch pivots between a maximum (MAX) power setting and a minimum (MIN) power setting. The MIN/MAX rocker switch is suitably located on a fixed handle portion of the handle assembly so that the rocker switch may be operated with the same finger that operates the distal rotation knob. However, a button switch may located on a moving part of the instrument, such as the trigger. Accordingly, the same finger can be used both for rotation of the shaft and operation of the power activation. The rocker switch may comprise identifying tactile features.

[0118] In one embodiment, a pivotably moveable trigger comprising a hook feature may be employed to actuate the jaws or clamping mechanism of the end effector assembly. A series of linkages translate the pivotal rotation of the trigger to axial movement of a yoke coupled to an actuation mechanism, which controls the opening and closing of the jaws of the clamping mechanism of the end effector assembly located at the distal end of the ultrasonic surgical instrument. In one embodiment, multiple links may be employed to provide mechanical advantage in a relatively short pivotal rotation span. The trigger may be operated by a finger other than the finger used to control the distal rotation knob or the toggle switch. The trigger activation finger(s) also may be employed to engage the hook feature to restore the jaws of the clamping mechanism of the end effector assembly to a predetermined state.

[0119] In one embodiment, a rotation knob may be located at a proximal end of the ultrasonic surgical instrument. The proximal rotation knob may be easily accessed with the thumb or finger and substantially reduces any obstructions or “reaching” that may be associated with a distally located rotation knob.

[0120] In one embodiment, rotation knobs may be located at distal and proximal ends of the ultrasonic surgical instrument. The distal and proximal rotation knobs may be easily accessed with either the thumb or fingers for convenience. Furthermore, the opposing nature of the thumb and finger actions used alternately substantially reduces winding of the electrical cord supplying power to the ultrasonic transducer. The natural tendency of the user is to rotate in only a downward direction because it is easier to push down than to push upward. With rotation knobs both distal and proximal, the a right-handed user uses the proximal knob to push down to rotate to the left, and uses the distal knob to push down to rotate to the right, thereby reducing or eliminating the “cord wind” of rotating only in one direction. The distal and proximal rotation knobs may be operated in conjunction with each other or may be rotated independently.

[0121] In various embodiments, multiple adapters may be provided to accommodate different sized hands. Adapters may comprise on open proximal end and can be removably attached to a fixed handle of a handle assembly either frictionally or by snap buttons. Adapters may comprise a closed proximal end to form a loop for receiving a thumb therethrough. Various embodiments of the loop adapter comprise a pliable polymeric element for added comfort.

[0122] In one embodiment, a handle assembly may comprise a projection formed on a fixed handle portion of the handle assembly. In another embodiment, the hand assembly may comprise protrusions formed on either side of the fixed handle of the hand assembly. These projections and protrusions reduce or minimize fatigue and increase control when using certain ultrasonic surgical instruments while operating the instrument.

[0123] FIG. 1 is a right side view of one embodiment of an ultrasonic surgical instrument 100. In the illustrated embodiment, the ultrasonic surgical instrument 100 may be employed in various surgical procedures including endoscopic or traditional open surgical procedures. In one embodiment, the ultrasonic surgical instrument 100 comprises a handle assembly 102, an elongated endoscopic shaft assembly 110, and an ultrasonic transducer 114. The handle assembly 102 comprises a trigger assembly 104, a distal rotation assembly 106, and a switch assembly 108. The elongated endoscopic shaft assembly 110 comprises an end effector assembly 112, which comprises elements to dissect tissue or mutually grasp, cut, and coagulate vessels and/or tissue, and actuating elements to actuate the end effector assembly 112. The handle assembly 102 is adapted to receive the ultrasonic transducer 114 at the proximal end. The ultrasonic transducer 114 is mechanically engaged to the elongated endoscopic shaft assembly 110 and portions of the end effector assembly 112. The ultrasonic transducer 114 is electrically coupled to a generator 116 via a cable 118. Although the majority of the figure drawings depict a multiple end effector assembly 112 for use in connection with endoscopic surgical procedures, the ultrasonic surgical instrument 100 may be employed in more traditional open surgical procedures. For the purposes herein, the ultrasonic surgical instrument 100 is described in terms of an endoscopic instrument; however, it is contemplated that an open version of the ultrasonic surgical instrument 100 also may include the same or similar operating components and features as described herein.

[0124] FIG. 2 is a right side view of one embodiment of the ultrasonic surgical instrument 100 shown in FIG. 1 without the ultrasonic transducer 114. In the illustrated embodiment, the trigger assembly 104 comprises a trigger 120 that works in conjunction with a fixed handle 122. The fixed handle 122 and the trigger 120 are ergonomically formed and adapted to interface comfortably with the user. The fixed handle 122 is integrally associated with the handle assembly 102. The trigger 120 is pivotally movable relative to the fixed handle 122 as explained in more detail below with respect to the operation of the ultrasonic surgical instrument 100. The trigger 120 is pivotally movable in direction 121A toward the fixed handle 122 when the user applies a squeezing force against the trigger 120. A spring element 182 (FIG. 14) causes the trigger 120 to pivotally move in direction 121B when the user releases the squeezing force against the trigger 120.

[0125] In one embodiment, the trigger 120 comprises an elongated trigger hook 124, which defines an aperture 126 between the elongated trigger hook 124 and the trigger 120. The aperture 126 is suitably sized to receive one or multiple fingers of the user therethrough. The trigger 120 also may comprise a resilient portion 120a molded over the trigger 120 substrate. The overmolded resilient portion 120a is formed to provide a more comfortable contact surface for control of the trigger 120 in outward direction 121B. In one embodiment, the overmolded resilient portion 120a may be provided over a portion of the elongated trigger hook 124. For example, in the illustrated embodiment, the overmolded resilient portion 120a is provided over the distal and top surfaces of the inner portion of the elongated trigger hook 120 to cushion the contact surface between the finger and the elongated trigger hook 124. The proximal surface of the elongated trigger hook 120 remains uncoated or coated with a non-resilient substrate to enable the user to easily slide their fingers in and out of the aperture 126. In other embodiments, the elongated trigger hook 124 may incorporate an overmolded component formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. The overmolded resilient portion 120a of the elongated trigger hook 124 may provide added comfort or form a more secure grip for the user. The overmolded resilient portion 120a on the top portion of the interior portion of the elongated trigger hook 124 may be contoured to alleviate edge pressure points against the fingers as they enter the aperture 126. In another embodiment, the geometry of the trigger forms a fully closed loop which defines an aperture suitably sized to receive one or multiple fingers of the user therethrough. The fully closed loop trigger also may comprise a resilient portion molded over the trigger substrate. The overmolded resilient portion is formed to provide a more comfortable contact surface for control of the trigger in outward direction.

[0126] In one embodiment, the fixed handle 122 comprises a proximal contact surface 128 and a grip anchor or saddle surface 130. The saddle surface 130 rests on the web where the thumb and the index finger are joined on the hand. The proximal contact surface 128 has a pistol grip contour that receives the palm of the hand in a normal pistol grip with no rings or apertures. The profile curve of the proximal contact surface 128 may be contoured to accommodate or receive the palm of the hand. To provide comfort and control while using the ultrasonic instrument 100, the profile of the proximal contact surface 128 is optimized to fit the natural anatomical contours in the valley of the center of the palm and base of the thumb. The saddle surface 130 provides a primary point of stability of the grip, which is the basis of the stability of control of the handle assembly 102. The saddle surface 130 is the reference point that determines a range of motion of the fingers and thumb relative to the proximal contact surface 128 of the fixed handle 122, the elongated trigger hook 124, the distal rotation assembly 106, and the toggle switch 132. A stabilization tail 131 is located towards a more proximal portion of the handle assembly 102. The stabilization tail 131 may be in contact with the uppermost web portion of the hand located between the thumb and the index finger to stabilize the handle assembly 102 and make the handle assembly 102 more controllable. The stabilization tail 131 provides an area extending in the proximal direction to allow the proximal weight of the ultrasonic surgical instrument 100 to be distributed to the top of the hand without restriction motion. The configuration of the saddle surface 130 and the stabilization tail 131 provides a greater sense of stability, comfort, and control for the user while manipulating the handle assembly 102.

[0127] In one embodiment, the switch assembly 108 may comprise a toggle switch 132. The toggle switch 132 may be implemented as a single component with a central pivot 304 (FIG. 34) located within inside the handle assembly 102 to eliminate the possibility of simultaneous activation. In one embodiment, the toggle switch 132 comprises a first projecting knob 132a and a second projecting knob 132b to set the power setting of the ultrasonic transducer 114 between a minimum power level (e.g., MIN) and a maximum power level (e.g., MAX). The toggle switch 132 rotates about the central pivot 304 as the first projecting knob 132a and the second projecting knob 132b are actuated. The one or more projecting knobs 132a, b are coupled to one or more arms that move through a small arc and cause electrical contacts (e.g., electrical elements 172b as shown in FIG. 36) to close or open an electric circuit to electrically energize or de-energize the ultrasonic transducer 114 in accordance with the activation of the first or second projecting knobs 132a,b. The toggle switch 132 is coupled to the generator 116 to control the activation of the ultrasonic transducer 114. The toggle switch 132 comprises one or more electrical power setting switches to activate the ultrasonic transducer 114 to set one or more power settings for the ultrasonic transducer 114. The forces required to activate the toggle switch 132 are directed substantially toward the saddle point 130, thus avoiding any tendency of the instrument to rotate in the hand when the toggle switch 132 is activated.

[0128] In one embodiment, the first and second projecting knobs 132a,b are located on the distal end of the handle assembly 102 such that they can be easily accessible by the user to activate the power with minimal, or substantially no, repositioning of the hand grip, making it suitable to maintain control and keep attention focused on the surgical site (e.g., a monitor in a laparoscopic procedure) while activating the toggle switch 132. The projecting knobs 132a,b may be configured to wrap around the side of the handle assembly 102 to some extent to be more easily accessible by variable finger lengths and to allow greater freedom of access to activation in awkward positions or for shorter fingers.

[0129] In one embodiment, the first and second projecting knobs 132a,b may be overmolded with pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. The overmolded material may be selected to withstand sterilization and to be biocompatible. Furthermore, the material may be selected to give a proper level of resilience and to provide adequate frictional resistance to surgical gloves. The overmolded portion may comprise projections with identifying tactile features useful for tactile identification or differentiation of the projecting knobs 132a,b or the rest of the handle assembly 102. As previously discussed, one of the projecting knobs 132a,b may comprises a texture or tactile surface that enables the user to differentiate between the first projecting knob 132a and the second projecting knob 132b. In the illustrated embodiment, the first projecting knob 132a comprises a plurality of tactile elements 132c, e.g., textured projections or “bumps” in the illustrated embodiment, to allow the user to differentiate the first projecting knob 132a (MAX) from the second projecting knob 132b (MIN).

[0130] In one embodiment, the toggle switch 132 may be operated by the hand of the user. The user may easily access the first and second projecting knobs 132a,b at any point while also avoiding inadvertent or unintentional activation at any time. The toggle switch 132 may readily operated with a finger to control the power to the ultrasonic assembly 114 and/or to the ultrasonic assembly 114. For example, the index finger may be employed to activate the first contact portion 132a to turn on the ultrasonic assembly 114 to a maximum (MAX) power level. The index finger may be employed to activate the second contact portion 132b to turn on the ultrasonic assembly 114 to a minimum (MIN) power level. The toggle switch 132 may be operated without the user having to look at the first or second projecting knob 132a,b. This allows the user to focus entirely on the monitor view during a laparoscopic procedure. Accordingly, the first projecting knob 132a or the second projecting knob 132b may comprise a texture or projections to tactilely differentiate between the first and second projecting knobs 132a,b without looking For example, in the illustrated embodiment, the first projecting knob 132a comprises a plurality of tactile elements 132c to allow the user to tactilely differentiate between the first projecting knob 132a (MAX) and the second projecting knob 132b (MIN). Other tactile textures or elements may be formed on either of the first or second projecting knobs 132a,b to for purposes of differentiation therebetween. The user does not have to reposition their grip in order to operate the toggle switch 132 and can easily control power levels while opening the jaws of the end effector 112.

[0131] In one embodiment, the distal rotation assembly 106 is rotatable without limitation in either direction about a longitudinal axis “T” (FIG. 13). The distal rotation assembly 106 is mechanically engaged to the elongated endoscopic shaft assembly 110. The distal rotation assembly 106 is located on a distal end of the handle assembly 102. The distal rotation assembly 106 comprises a cylindrical hub 133 and a rotation knob 134 formed over the hub 133. The hub 133 mechanically engages the elongated endoscopic shaft assembly 110. The rotation knob 134 may comprise fluted polymeric features and may be engaged by a finger (e.g., an index finger) to rotate the elongated endoscopic shaft assembly 110. The hub 133 may comprise a material molded over the primary structure to form the rotation knob 134. The rotation knob 134 may be overmolded over the hub 133. The hub 133 comprises an end cap portion 133a that is exposed at the distal end. The end cap portion 133a of the hub 133 may contact the surface of a trocar during laparoscopic procedures. The hub 133 may be formed of a hard durable plastic such as polycarbonate to alleviate any friction that may occur between the end cap portion 133a and the trocar. The rotation knob 134 may comprise “scallops” or flutes formed of raised ribs 134a and concave portions 134b located between the ribs 134a to provide a more precise rotational grip. In one embodiment, the rotation knob 134 may comprise a plurality of flutes (e.g., three or more flutes). In other embodiments, any suitable number of flutes may be employed. The rotation knob 134 may be formed of a softer polymeric material overmolded onto the hard plastic material. For example, the rotation knob 134 may be formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. This softer overmolded material may provide a greater grip and more precise control of the movement of the rotation knob 134. It will be appreciated that any materials that provide adequate resistance to sterilization, are biocompatible, and provide adequate frictional resistance to surgical gloves may be employed to form the rotation knob 134.

[0132] In one embodiment, the handle assembly 102 may comprise and may be configured with ergonomic features to enable the user to easily access and operate the multiple functions and controls of the ultrasonic surgical instrument 100. Accordingly, a finger may be used to operate the distal rotation knob 134 located at the distal portion of the handle assembly 102. The rotation knob 134 is coupled to the elongated endoscopic shaft assembly 110 of the ultrasonic transmission waveguide shaft by the hub 133. Thus, the finger can be used to rotate the ultrasonic transmission waveguide elongated endoscopic shaft assembly 110 by rotating the rotation knob 134. The MIN/MAX power buttons of the toggle switch 132 are suitably located on a distal end of the handle assembly 122 of the instrument 100 so that they may be operated with the index finger, for example. Accordingly, the index finger may be used to rotate the shaft of the elongated endoscopic shaft assembly 110 to orient the jaws of the clamping mechanism of the end effector assembly 112 in a desired position and to activate the ultrasonic transducer 114 to a suitable power level.

[0133] FIG. 3 is a left perspective view of one embodiment of the ultrasonic surgical instrument 100 showing the handle assembly 102, the distal rotation assembly 106, the elongated endoscopic shaft assembly 110, and the end effector assembly 112. With reference to FIGS. 3-9, in the illustrated embodiment the elongated endoscopic shaft assembly 110 comprises a distal end 138 dimensioned to mechanically engage the end effector assembly 112 and a proximal end 136 that mechanically engages the handle assembly 102 and the distal rotation assembly 106. The proximal end 136 of the elongated endoscopic shaft assembly 110 is received within the handle assembly 102 and the distal rotation assembly 106. More details relating to the connections between the elongated endoscopic shaft assembly 110, the handle assembly 102, and the distal rotation assembly 106 are provided in the description of FIGS. 14 and 24.

[0134] In one embodiment, the handle assembly 102 is formed from two (2) housing portions or shrouds comprising a first portion 102a and a second portion 102b. From the perspective of a user viewing the handle assembly 102 from the distal end towards the proximal end, the first portion 102a is considered the right portion and the second portion 102b is considered the left portion. Each of the first and second portions 102a,b includes a plurality of interfaces 158 (FIG. 14) dimensioned to mechanically align and engage each another to form the handle assembly 102 and enclosing the internal working components thereof. The fixed handle 122, which is integrally associated with the handle assembly 102, takes shape upon the assembly of the first and second portions 102a and 102b of the handle assembly 102. A plurality of additional interfaces (not shown) may be disposed at various points around the periphery of the first and second portions 102a and 102b of the handle assembly 102 for ultrasonic welding purposes, e.g., energy direction/deflection points. The first and second portions 102a and 102b (as well as the other components described below) may be assembled together in any fashion known in the art. For example, alignment pins, snap-like interfaces, tongue and groove interfaces, locking tabs, adhesive ports, may all be utilized either alone or in combination for assembly purposes.

[0135] In one embodiment, the elongated endoscopic shaft assembly 110 comprises a proximal end 136 adapted to mechanically engage the handle assembly 102 and the distal rotation assembly 106; and a distal end 138 adapted to mechanically engage the end effector assembly 112. The elongated endoscopic shaft assembly 110 comprises an outer tubular sheath 142 and a reciprocating tubular actuating member 144 located within the outer tubular sheath 142. The proximal end of the tubular reciprocating tubular actuating member 144 is mechanically engaged to the trigger 120 of the handle assembly 102 to move in either direction 146A or 146B in response to the actuation and/or release of the trigger 120. The pivotably moveable trigger 120 may be employed to actuate the jaws or clamping mechanism of the end effector assembly 112. A series of linkages translate the pivotal rotation of the trigger 120 to axial movement of a yoke coupled to an actuation mechanism, which controls the opening and closing of the jaws of the clamping mechanism of the end effector assembly 112. The distal end of the tubular reciprocating tubular actuating member 144 is mechanically engaged to the end effector assembly 112. In the illustrated embodiment, the distal end of the tubular reciprocating tubular actuating member 144 is mechanically engaged to a clamp arm assembly 150, which is pivotable about a pivot point 154, to open and close the clamp arm assembly 150 in response to the actuation and/or release of the trigger 120. For example, in the illustrated embodiment, the clamp arm assembly 150 is movable in direction 148A from an open position to a closed position about a pivot point 154 when the trigger 120 is squeezed in direction 121A. The clamp arm assembly 150 is movable in direction 148B from a closed position to an open position about the pivot point 154 when the trigger 120 is released or outwardly contacted in direction 121B.

[0136] In one embodiment, the end effector assembly 112 is attached at the distal end 138 of the elongated endoscopic shaft assembly 110 and includes a clamp arm assembly 150 and a blade 152. The jaws of the clamping mechanism of the end effector assembly 112 are formed by clamp arm assembly 150 and the blade 152. The blade 152 is ultrasonically actuatable and is acoustically coupled to the ultrasonic transducer 114. The trigger 120 on the handle assembly 102 is ultimately connected to a drive assembly, which together, mechanically cooperate to effect movement of the clamp arm assembly 150. Squeezing the trigger 120 in direction 121A moves the clamp arm assembly 150 in direction 148A from an open position, wherein the clamp arm assembly 150 and the blade 152 are disposed in a spaced relation relative to one another, to a clamped or closed position, wherein the clamp arm assembly 150 and the blade 152 cooperate to grasp tissue therebetween. The clamp arm assembly 150 may comprise a clamp pad 158 to engage tissue between the blade 152 and the clamp arm 150. Releasing the trigger 120 in direction 121B moves the clamp arm assembly 150 in direction 148B from a closed relationship, to an open position, wherein the clamp arm assembly 150 and the blade 152 are disposed in a spaced relation relative to one another.

[0137] The proximal portion of the handle assembly 102 comprises a proximal opening 156 to receive the distal end of the ultrasonic assembly 114. The ultrasonic assembly 114 is inserted in the proximal opening 156 and is mechanically engaged to the elongated endoscopic shaft assembly 110.

[0138] In one embodiment, the elongated trigger hook 124 portion of the trigger 120 provides a longer trigger lever with a shorter span and rotation travel. The longer lever of the elongated trigger hook 124 allows the user to employ multiple fingers within the aperture 126 to operate the elongated trigger hook 124 and cause the trigger 120 to pivot in direction 121B to open the jaws of the end effector assembly 112. For example, the user may insert three fingers (e.g., the middle, ring, and little fingers) in the aperture 126. Multiple fingers allows the surgeon to exert higher input forces on the trigger 120 and the elongated trigger hook 124 to activate the end effector assembly 112. The shorter span and rotation travel creates a more comfortable grip when closing or squeezing the trigger 120 in direction 121A or when opening the trigger 120 in the outward opening motion in direction 121B lessening the need to extend the fingers further outward. This substantially lessens hand fatigue and strain associated with the outward opening motion of the trigger 120 in direction 121B. The outward opening motion of the trigger may be spring-assisted by spring element 182 (FIG. 14) to help alleviate fatigue. The opening spring force is sufficient to assist the ease of opening, but not strong enough to adversely impact the tactile feedback of tissue tension during spreading dissection.

[0139] For example, during a surgical procedure either the index finger may be used to control the rotation of the elongated endoscopic shaft assembly 110 to locate the jaws of the end effector assembly 112 in a suitable orientation. The middle and/or the other lower fingers may be used to squeeze the trigger 120 and grasp tissue within the jaws. Once the jaws are located in the desired position and the jaws are clamped against the tissue, the index finger can be used to activate the toggle switch 132 to adjust the power level of the ultrasonic transducer 114 to treat the tissue. Once the tissue has been treated, the user the may release the trigger 120 by pushing outwardly in the distal direction against the elongated trigger hook 124 with the middle and/or lower fingers to open the jaws of the end effector assembly 112. This basic procedure may be performed without the user having to adjust their grip of the handle assembly 102.

[0140] FIGS. 10-12 illustrate the connection of the elongated endoscopic shaft assembly 110 relative to the end effector assembly 112. As previously described, in the illustrated embodiment, the end effector assembly 112 comprises a clamp arm assembly 150 and a blade 152 to form the jaws of the clamping mechanism. The blade 152 may be an ultrasonically actuatable blade acoustically coupled to the ultrasonic transducer 114. The trigger 120 is mechanically connected to a drive assembly. Together, the trigger 120 and the drive assembly mechanically cooperate to move the clamp arm assembly 150 to an open position in direction 148B wherein the clamp arm assembly 150 and the blade 152 are disposed in spaced relation relative to one another, to a clamped or closed position in direction 148A wherein the clamp arm assembly 150 and the blade 152 cooperate to grasp tissue therebetween. The clamp arm assembly 150 may comprise a clamp pad 158 to engage tissue between the blade 152 and the clamp arm 150. The distal end of the tubular reciprocating tubular actuating member 144 is mechanically engaged to the end effector assembly 112. In the illustrated embodiment, the distal end of the tubular reciprocating tubular actuating member 144 is mechanically engaged to the clamp arm assembly 150, which is pivotable about the pivot point 154, to open and close the clamp arm assembly 150 in response to the actuation and/or release of the trigger 120. For example, in the illustrated embodiment, the clamp arm assembly 150 is movable from an open position to a closed position in direction 148A about a pivot point 154 when the trigger 120 is squeezed in direction 121A. The clamp arm assembly 150 is movable from a closed position to an open position in direction 148B about the pivot point 154 when the trigger 120 is released or outwardly contacted in direction 121B.

[0141] FIG. 13 is a left perspective view of one embodiment of the ultrasonic surgical instrument shown in FIG. 3 showing a central longitudinal axis “T”.

[0142] FIG. 14 is an exploded view of the ultrasonic surgical instrument 100 shown in FIG. 3. In the illustrated embodiment, the exploded view shows the internal elements of the handle assembly 102, the handle assembly 102, the distal rotation assembly 106, the switch assembly 108, and the elongated endoscopic shaft assembly 110. With reference now to FIGS. 14-24, in the illustrated embodiment, the first and second portions 102a,b mate to form the handle assembly 102. The first and second portions 102a,b each comprises a plurality of interfaces 158 dimensioned to mechanically align and engage one another to form the handle assembly 102 and enclose the internal working components of the ultrasonic surgical instrument 100. The rotation knob 134 is mechanically engaged to the outer tubular sheath 142 so that it may be rotated in circular direction 140 up to 360°. The outer tubular sheath 142 is located over the reciprocating tubular actuating member 144, which is mechanically engaged to and retained within the handle assembly 102 via a plurality of coupling elements 160. The coupling elements 160 may comprise an O-ring 160a, a tube collar cap 160b, a distal washer 160c, a proximal washer 160d, and a thread tube collar 160e. The reciprocating tubular actuating member 144 is located within a reciprocating yoke 170, which is retained between the first and second portions 102a,b of the handle assembly 102. The yoke 170 is part of a reciprocating yoke assembly 173. A series of linkages translate the pivotal rotation of the elongated trigger hook 120 to the axial movement of the reciprocating yoke 170, which controls the opening and closing of the jaws of the clamping mechanism of the end effector assembly 112 at the distal end of the ultrasonic surgical instrument 100. In one embodiment, a four-link design provides mechanical advantage in a relatively short rotation span, for example.

[0143] In one embodiment, an ultrasonic transmission waveguide 164 is disposed inside the reciprocating tubular actuating member 144. The distal end 138 of the ultrasonic transmission waveguide 164 is acoustically coupled to the blade 152 and the proximal end 136 of the ultrasonic transmission waveguide 164 is received within the handle assembly 102. The proximal end 136 of the ultrasonic transmission waveguide 164 is adapted to acoustically couple to the distal end of the ultrasonic transducer 114 as discussed in more detail below. The ultrasonic transmission waveguide 164 is isolated from the other elements of the elongated endoscopic shaft assembly 110 by a protective sheath 166 and a plurality of isolation elements 168, such as silicone rings. The outer tubular sheath 142, the reciprocating tubular actuating member 144, and the ultrasonic transmission waveguide 164 are mechanically engaged by a pin 162. The switch assembly 108 comprises the toggle switch 132 and electrical elements 172a,b to electrically energize the ultrasonic transducer 114 in accordance with the activation of the first or second projecting knobs 132a,b.

[0144] In one embodiment, the outer tubular sheath 142 isolates the user or the patient from the ultrasonic vibrations of the ultrasonic transmission waveguide 164. The outer tubular sheath 142 generally includes a hub 163. The outer tubular sheath 142 is threaded onto the distal end of the handle assembly 102. The ultrasonic transmission waveguide 164 extends through the opening of the outer tubular sheath 142 and the isolation elements 168 isolate the ultrasonic transmission waveguide 104 from the outer tubular sheath 142. The outer tubular sheath 142 may be attached to the waveguide 164 with the pin 162. The hole to receive the pin 162 in the waveguide 164 may occur nominally at a displacement node. The waveguide 164 may screw or snap into the hand piece handle assembly 102 by a stud 226 (FIG. 27). Flat portions on the hub 163 may allow the assembly to be torqued to a required level.

[0145] In one embodiment, the hub 163 portion of the outer tubular sheath 142 is preferably constructed from plastic and the tubular elongated portion of the outer tubular sheath 142 is fabricated from stainless steel. Alternatively, the ultrasonic transmission waveguide 164 may comprise polymeric material surrounding it to isolate it from outside contact.

[0146] In one embodiment, the distal end of the ultrasonic transmission waveguide 164 may be coupled to the proximal end of the blade 152 by an internal threaded connection, preferably at or near an antinode. It is contemplated that the blade 152 may be attached to the ultrasonic transmission waveguide 164 by any suitable means, such as a welded joint or the like. Although the blade 152 may be detachable from the ultrasonic transmission waveguide 164, it is also contemplated that the single element end effector (e.g., the blade 152) and the ultrasonic transmission waveguide 164 may be formed as a single unitary piece.

[0147] In one embodiment, the trigger 120 is coupled to a linkage mechanism to translate the rotational motion of the trigger 120 in directions 121A and 121B to the linear motion of the reciprocating tubular actuating member 144 in corresponding directions 146A and 146B. The trigger 120 comprises a first set of flanges 182 with openings formed therein to receive a first yoke pin 176a. The first yoke pin 176a is also located through a set of openings formed at the distal end of the yoke 170. The trigger 120 also comprises a second set of flanges 180 to receive a first end 176a of a link 176. A trigger pin 174 is received in openings formed in the link 176 and the second set of flanges 180. The trigger pin 174 is received in the openings formed in the link 176 and the second set of flanges 180 and is adapted to couple to the first and second portions 102a,b of the handle assembly 102 to form a trigger pivot point 190 (FIGS. 25, 26) for the trigger 120. A second end 176b of the link 176 is received in a slot 184 formed in a proximal end of the yoke 170 and is retained therein by a second yoke pin 178b. As the trigger 120 is pivotally rotated about the pivot point 190 formed by the trigger pin 174, the yoke translates horizontally along longitudinal axis “T” in a direction indicated by arrows 146A,B.

[0148] FIGS. 25 and 26 illustrate relationships between various user interfaces of one embodiment of the handle assembly 102. In the illustrated embodiment, the user may employ a control finger to activate the power buttons of the toggle switch 132 and to control the rotation of the rotation knob 134 and precisely control the rotation of the end effector assembly 112. The control finger may be the index finger; however, the embodiments are not limited in this context. As illustrated, a control finger location 186a is used to operate (e.g., rotate) the distal rotation knob 134. The distance between the control finger location 186a and the saddle surface 130 is “d1”. In one embodiment, for example, d1 may be approximately 3.17 inches. Without changing the grip relative to the fixed handle 122 the user also may operate the first projecting knob 132a by locating a finger in control finger location 186b to set the power to a first level (e.g., MAX) and may operate the second projecting knob 132b by locating the finger at control finger location 186c to set the power to a second level (e.g., MIN). The distance between the control finger location 186b and the saddle surface 130 is “d2” and the distance between the control finger location 186c and the saddle surface 130 is “d3”. In one embodiment, for example, d2 may be approximately 2.55 inches and d3 may be approximately 2.46 inches. Accordingly, the user may easily and readily locate the control finger at three control finger locations 186a, 186b, and 186c without re-gripping the handle assembly 102 to operate the respective distal rotation knob 134, the first projecting knob 132a, and the second projecting knob 132b. Each of the rotation and power controls are readily accessible with the control finger without being too crowded together and resulting in a balanced access of all three.

[0149] In one embodiment, a trigger finger of the user may be located in a first position 188a within the aperture 126 to operate the trigger 120. The distance between the first position 188a and the saddle surface 130 is “d4”. In one embodiment for example, d4 may be approximately 2.11 inches. The trigger finger may be the middle finger. As illustrated, the trigger finger may be contacted with the molded resilient portion 120a of the trigger 120. As the trigger 120 is squeezed in direction 121A, it pivots about the pivot point 190 from a fully open to a fully closed position, shown in phantom in FIG. 26. As the trigger 120 pivots about the pivot point 190 from a fully open position to a fully closed position, the trigger finger location moves from the trigger finger location 188a to the trigger finger location 188b, shown in phantom.

[0150] The spread angles φ₁-φ₃ are defined as the angles formed between the trigger finger location 188a with the trigger 120 in a fully open position and a control finger located on a control element. A first angle φ₁ is defined as the angle formed between the trigger finger location 188a and the control finger location 186a in contact with the distal rotation knob 134. In one embodiment, for example, φ₁ may be approximately forty-six degrees. A second angle φ₂ is defined as the angle formed between the trigger finger location 188a and the control finger location 186b in contact with the first projecting knob 132a. In one embodiment, for example, φ₂ may be approximately thirty-three degrees. A third angle φ₃ is defined as the angle formed between the trigger finger location 188a and the control finger location 186c in contact with the second projecting knob 132b. In one embodiment, angle φ₃ may be approximately twenty degrees and the angle φ₄ between the control finger location 188a and the axis S may be approximately nineteen degrees. The access spread is a combination of the distance “d” between the saddle surface 130 and the control finger location 186a, 186b, or 186c and the spread angle φ between the control finger location and the trigger finger location. The distances d₁, d₂, and d₃ and the spread angles φ₁, φ₂, and φ₃ are optimized for ergonomic purposes. For example, the spread angles may be selected such that:
φ₃<φ₂<φ₁; and
d₃<d₂<d₁.

[0151] The spread angle φ₁ represents the spread between the control finger location 186a on the distal rotation knob 134 and the trigger finger location 188a. The access spread 192a between the control finger position 186a and the trigger finger position 188a is the largest of the three access spreads 192a, 192b, and 192c. Operation of the distal rotation knob 134 requires the most finger spread of all the other controls. Further, the distal rotation knob 134 requires a different force vector (e.g., downward) to actuate than the first projecting knob 132a or the second projecting knob 132b, which requires less strain on the finger. The distal rotation knob 134 can be configured to deactivate and lock-out when the trigger 120 is in the fully closed position, shown in phantom, which also alleviates the “worst case” finger spread angle φ₁. In general, the spacing 196 between the distal rotation knob 134 and the first projecting knob 132a may be selected to minimize crowding therebetween and to minimize difficulty of access for larger fingers.

[0152] The spread angle φ₂ represents the spread between the control finger location 186b at the first projecting knob 132a and the trigger finger location 188a. The access spread 192b between the control finger location 186b and the trigger finger location 188a is slightly greater than the access spread 192c between the control finger location 186c and the trigger finger location 188a and requires more finger spread to access the first projecting knob 132a than the second projecting knob 132b. The first projecting knob 132a is located sufficiently apart from the second projecting knob 132b to minimize any perceived risk of inadvertent activation. In addition, the first projecting knob 132a is spaced sufficiently apart from the distal rotation knob 134 to minimize crowding and any difficulty of access for larger fingers. The spacing 196 between the distal rotation knob 134 and the first projecting knob 132a may be selected such that it is minimized to keep the distal rotation knob 134 within reach of the control finger location 186a and is maximized to avoid crowding between the distal rotation knob 134 and the first projecting knob 132a.

[0153] The spread angle φ₃ represents the spread between the control finger location 186c at the second projecting knob 132b and the trigger finger location 188a. The access spread 192c between the control finger location 186c and the trigger finger position 188a is the least spread required between the middle and control fingers and accordingly results in the lowest finger strain. Access to the second projecting knob 132b requires the least finger spread of all the controls and therefore tends to be the easiest to activate. In the fully open position, the second projecting knob 132b is located as low as possible without being too crowded against the trigger 120 and thus avoiding “crossing” the trigger finger. The spacing 194 between the second projecting knob 132b and the trigger 120a may be selected to minimize the finger spread angle required to reach the first projecting knob 132a when the trigger 120 is in the fully closed position, shown in phantom, and the trigger finger is at position 188b, also shown in phantom.

[0154] In one embodiment, the location of the trigger pivot 190 may be selected to control and optimize the arc of motion of the trigger 120 as it pivots from a fully open position, shown in solid line, to a fully closed position, shown in phantom, especially as it relates to the relative trigger finger location at each end of the span. The ideal motion arc is slightly upward moving from closed to open, to relate to the natural opening motion of the fingers. The fully closed position slightly increases the angle of the finger spread required to access controls, but is acceptable in balance to the natural motion arc of the trigger 120. When the trigger 120 is in the fully closed position, the trigger finger location 188b slightly increases the angle of the finger spread angle φ required to access the various controls (i.e., the angle φ formed between the middle and the control fingers). The increase, however, is minimized to be within an acceptable balance to the natural motion arc of the trigger 120.

[0155] FIG. 26 illustrates relationships between various user interfaces of one embodiment of the handle assembly 102. In the illustrated embodiment, the handle assembly 102 may be defined as having four separate axis. A longitudinal axis “T” that coincides with the longitudinal axis of the elongated endoscopic shaft assembly 110, a saddle surface axis “S”, a user input axis “U”, a base axis “L”, the trigger 120 pivot point 190, a center point 191 of the elongated trigger hook 124, the saddle surface 130, the control finger locations 186a, 186b, 186c, and the trigger finger locations 188a, 188b. The trigger hook 124 defines an arcuate portion defined by radius “r₁” and center point 191. The handle assembly 102 provides suitable spacing between the trigger 120 and the fixed handle 122 at full closure. The spacing/contouring of the second projecting knob 132b (e.g., MIN button) and the top of the elongated trigger hook 124 pushes out the trigger finger when opening the trigger 120 while activating the second projecting knob 132b.

[0156] In one embodiment, the activation user input force “f₁” is the force necessary to activate the first projecting knob 132a or the second projecting knob 132b. In one embodiment, the force f₁ is approximately 400 g+/−80 g. The activation user input force f₁ is a balance between minimizing user fatigue (not too hard) and minimizing risk of inadvertent activation (not too light). The activation user input force f₁ is measured along the A-E vector (the vector from the saddle surface 130 to the finger location 186b) to activate the first projecting knob 132a and the A-F vector (the vector from the saddle surface 130 to the finger location 186c) to activate the second projecting knob 132b.

[0157] In one embodiment, a control (e.g., index) finger “rest area” 193 is defined as the space between the first projecting knob 132a and the second projecting knob 132b (e.g., MIN/MAX button spacing). A user can apply up to approximately 1.5 lbf of force on the rest area 193 between the first projecting knob 132a and the second projecting knob 132b with the control finger without activating power.

[0158] In one embodiment, the first projecting knob 132a and the second projecting knob 132b may be activated with a directional pressure vector from 0° to 30° to either side relative to the medial center plane of the hand assembly 102. This provides greater access to the first projecting knob 132a and the second projecting knob 132b when the wrist is in an extreme position with shorter fingers.

[0159] In one embodiment, the center line between the second projecting knob 132b and the highest finger located within the aperture 126 defined by the elongated trigger hook 124 is approximately at least 0.650″ to maximize comfort and minimize a feeling of “crossing” two adjacent fingers.

[0160] In one embodiment, the finger clearance within the aperture 126 of the elongated trigger hook 124 is approximately at least 0.650″ to avoid finger entrapment.

[0161] In one embodiment, the user input axis (U) is defined as the axis U directly between the middle and ring finger positions on the trigger 120. The trigger 120 closing force applied by the user is defined as the force f₂ measured along the U-X vector (the vector from the proximal contact surface 128 to the first position 188a within the aperture 126). In one embodiment, the force required to close the trigger 120 to a fully closed position, as measured along U-X vector, may be approximately less than 6.14 lbs, based upon the following:

• [0162] 140.8 lbs=maximum full-hand grip force for 5% small female;
• [0163] 40.8 lbs×0.33=13.64 lbs (67% reduction for comfortable grip force);
• [0164] 13.64 lbs×0.60=8.18 lbs (40% reduction for poor posture); and
• [0165] 8.18 lbs×0.75=6.14 lbs (25% reduction for removing index from the full grip: relative finger strengths: Index: 25%, Middle: 35%, Ring: 25%, little: 14%, source: NCBI Pub Med, 07/04).
  1In one embodiment, a trigger 120 abuse closing force is defined as the closing force generated when the trigger is closed by applying pressure on the distal surface of the elongated trigger hook 124. In one embodiment, the reasonable abuse force that the trigger 120 can withstand is approximately 15.00 lbs, based upon that the high end of the actual closing force manufacturing variation is 5 lbs. and it would be rare to expect that the user will exert more that three-times the required force.

[0166] In one embodiment, the trigger 120 opening force is defined as the force f₃ required by the user to fully open trigger 120, as measured along the U-X vector. In one embodiment, the force f₃ is approximately 0.0+0.5/−1.5 lbf. In one embodiment, the handle assembly 102 incorporates some means of spring-assisted opening to overcome the friction in the system such as spring element 182 (FIG. 14). In one embodiment, the jaws of the end effector assembly 112 should become fully open on their own with minimal force required. The “automatic” full opening suitably enhances ease of use when applying multiple closure “bites” in succession. Minimizing the force required for the jaws of the end effector assembly 112 to open reduces risk of losing tactile feedback during spreading dissection (surgeons want to feel the tissue tension being applied as much as possible, not the spring), for example.

[0167] In one embodiment, the contact surface width of the trigger 120 may be approximately 0.760″+/−0.200″ as measured at the user input axis “U” to provide maximum comfort and avoid pressure points.

[0168] In one embodiment, the length of the elongated trigger hook 124 as measured from the elongated trigger hook center 191 to the end of the forward hook loop may be approximately 1.090″+/−0.080″ to facilitate two-finger contact for an outward opening stroke of the trigger 120.

[0169] In one embodiment, the length of the trigger 120 as measured from the elongated trigger hook center 191 to the lowermost end of the trigger 120 should be approximately 2.480″+/−0.080″ to facilitate three-finger contact for closing stroke.

[0170] In one embodiment, the longitudinal center of gravity may be located approximately 0.700″+/−0.150″ proximal to the origin of the elongated endoscopic shaft assembly 110 at point as defined by the location of the insulated pin. The total weight of the device defined as the handle assembly fully assembled the cable 118 cut off at a proximal termination of strain relief. In one embodiment, the center of gravity may be kept closer to the center of the palm of the user for maximum feeling of control and stability.

[0171] In one embodiment, the palm surface length of the fixed handle 122 may be approximately 2.900″+/−0.125″ as measured vertically from A-L (from the saddle surface 130 to the base of the fixed handle 122). This distance may be determined by balancing maximizing size for larger hand comfort and stability and minimizing potential interference of the handle assembly 102 with a patient (usually happens if legs are raised) or table.

[0172] In one embodiment, the palm surface width does not exceed approximately 1.320″. This distance may be determined by balancing comfort against the palm of the user when closing pressure is applied to the trigger 120, access around the back surface area of the fixed handle 122 to the front controls for smaller hands, and overall “fit” in the hand of the user. The side surfaces of the fixed handle 122 may be curved and contoured to naturally fit the palm of a hand and provide stability for the thumb and index finger grip locations.

[0173] In one embodiment, the fully closed grip span as measured from U-X′ may be greater than approximately 1.600″. The fully open grip span as measured from U-X may be less than a maximum of approximately 2.300″.

[0174] In one embodiment, the distal rotation knob 134 user interface may comprise a multi-flute design, with a finger-contact radius of approximately 0.250″+/−0.050″ for each flute 134a. In one embodiment, the flutes 134a may be overmolded to increase gripping ability on the distal rotation knob 134.

[0175] In one embodiment, the rotation force is defined as the frictional force of the distal rotation knob 134 when it is connected to the handle assembly 112. The rotation force should provide a torque resistance of approximately 3.5-12.5 in-oz. This value may be determined by balancing suitable resistance at the low end to overcome reversal of the shaft due to winding of the cord and minimizing user input force at the high end to minimize fatigue.

[0176] In one embodiment, the overmolding compliance of the molded resilient portion 120a of the trigger 120 surface may be less than approximately 0.040″ at any point of contact in the loaded trigger motion to maximize tactile feedback. This value may be determined by balancing providing increased user comfort during repetitive trigger actuation (especially outward finger extension) and not losing tactile feedback of forces being applied to tissue.

[0177] In one embodiment, the overall configuration of the handle assembly 102 may be based upon a pistol-grip design, with an optimal palm proximal contact surface 128 (P) as described and illustrated in the embodiments herein. In one embodiment, the optimization of the proximal contact surface 128 may comprise a contact surface that is best defined by an organic curve that naturally fits the palm of the hand, rather than a specified angle of the grip. This ideal curve provides maximum grip comfort, control, and stability. Locating the saddle surface 130 directly below the location of the stabilization tail 131 provides added feeling of control and stability in the nook or web defined between the thumb and index finger.

[0178] As can also be seen in FIG. 26, the contact surface 128 may have a radius RH that is measured from reference point RP. Reference point RP may be located a first distance HD1 from axis S and a second distance HD2 from point A. In one embodiment, for example, radius RH may be approximately 2.99 inches, distance HD1 may be approximately 2.27 inches and distance HD2 may be approximately 2.20 inches. Also in various embodiments, the stabilization tail 131 may have a first radius portion RT of approximately 0.40 inches and a second radius RT2 measured from a second reference point RP2 that may be approximately 2.91 inches. The second reference point RP2 may be located a distance TL from point A, wherein TL may be approximately 1.31 inches and a distance TL2 from axis S which may be approximately 2.33 inches.

[0179] In one embodiment, the edges of the handle assembly 102 contacting the palm or fingers of the user have a minimum radius of approximately 0.040″, unless the material has a durometer of 70 A or less.

[0180] FIG. 27 illustrates one embodiment of an ultrasonic surgical instrument 100. In the illustrated embodiment, a cross-sectional view of the ultrasonic transducer 114 is shown within a partial cutaway view of the handle assembly 102. One embodiment of the ultrasonic surgical instrument 100 comprises the ultrasonic signal generator 116 coupled to the ultrasonic transducer 114, comprising a hand piece housing 198, and an ultrasonically actuatable single or multiple element end effector assembly 112. As previously discussed, the end effector assembly 112 comprises the ultrasonically actuatable blade 152 and the clamp arm 150. The ultrasonic transducer 114, which is known as a “Langevin stack”, generally includes a transduction portion 200, a first resonator portion or end-bell 202, and a second resonator portion or fore-bell 204, and ancillary components. The total construction of these components is a resonator. The ultrasonic transducer 114 is preferably an integral number of one-half system wavelengths (nλ/2; where “n” is any positive integer; e.g., n=1, 2, 3 . . . ) in length as will be described in more detail later. An acoustic assembly 206 includes the ultrasonic transducer 114, a nose cone 208, a velocity transformer 218, and a surface 210.

[0181] It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping the handle assembly 102 of the handle assembly 102. Thus, the end effector assembly 112 is distal with respect to the more proximal handle assembly 102 of the handle assembly 102. It will be further appreciated that, for convenience and clarity, spatial terms such as “top” and “bottom” also are used herein with respect to the clinician gripping the handle assembly 102. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[0182] In one embodiment, the distal end of the end-bell 202 is connected to the proximal end of the transduction portion 200, and the proximal end of the fore-bell 204 is connected to the distal end of the transduction portion 200. The fore-bell 204 and the end-bell 202 have a length determined by a number of variables, including the thickness of the transduction portion 200, the density and modulus of elasticity of the material used to manufacture the end-bell 202 and the fore-bell 22, and the resonant frequency of the ultrasonic transducer 114. The fore-bell 204 may be tapered inwardly from its proximal end to its distal end to amplify the ultrasonic vibration amplitude as the velocity transformer 218, or alternately may have no amplification. A suitable vibrational frequency range may be about 20 Hz to 120 kHz and a well-suited vibrational frequency range may be about 30-100 kHz. A suitable operational vibrational frequency may be approximately 55.5 kHz, for example.

[0183] In one embodiment, the piezoelectric elements 212 may be fabricated from any suitable material, such as, for example, lead zirconate-titanate, lead meta-niobate, lead titanate, barium titanate, or other piezoelectric ceramic material. Each of positive electrodes 214, negative electrodes 216, and the piezoelectric elements 212 has a bore extending through the center. The positive and negative electrodes 214 and 216 are electrically coupled to wires 220 and 222, respectively. The wires 220 and 222 are encased within the cable 118 and electrically connectable to the ultrasonic signal generator 116.

[0184] The ultrasonic transducer 114 of the acoustic assembly 206 converts the electrical signal from the ultrasonic signal generator 116 into mechanical energy that results in primarily a standing acoustic wave of longitudinal vibratory motion of the ultrasonic transducer 114 and the blade 152 portion of the end effector assembly 112 at ultrasonic frequencies. In another embodiment, the vibratory motion of the ultrasonic transducer may act in a different direction. For example, the vibratory motion may comprise a local longitudinal component of a more complicated motion of the tip of the elongated endoscopic shaft assembly 110. A suitable generator is available as model number GEN04, from Ethicon Endo-Surgery, Inc., Cincinnati, Ohio. When the acoustic assembly 206 is energized, a vibratory motion standing wave is generated through the acoustic assembly 206. The ultrasonic surgical instrument 100 is designed to operate at a resonance such that an acoustic standing wave pattern of predetermined amplitude is produced. The amplitude of the vibratory motion at any point along the acoustic assembly 206 depends upon the location along the acoustic assembly 206 at which the vibratory motion is measured. A minimum or zero crossing in the vibratory motion standing wave is generally referred to as a node (i.e., where motion is minimal), and a local absolute value maximum or peak in the standing wave is generally referred to as an anti-node (i.e., where local motion is maximal). The distance between an anti-node and its nearest node is one-quarter wavelength (λ/4).

[0185] The wires 220 and 222 transmit an electrical signal from the ultrasonic signal generator 116 to the positive electrodes 214 and the negative electrodes 216. The piezoelectric elements 212 are energized by the electrical signal supplied from the ultrasonic signal generator 116 in response to an actuator 224, such as a foot switch, for example, to produce an acoustic standing wave in the acoustic assembly 206. The electrical signal causes disturbances in the piezoelectric elements 212 in the form of repeated small displacements resulting in large alternating compression and tension forces within the material. The repeated small displacements cause the piezoelectric elements 212 to expand and contract in a continuous manner along the axis of the voltage gradient, producing longitudinal waves of ultrasonic energy. The ultrasonic energy is transmitted through the acoustic assembly 206 to the blade 152 portion of the end effector assembly 112 via a transmission component or an ultrasonic transmission waveguide portion 164 of the elongated endoscopic shaft assembly 110.

[0186] In one embodiment, in order for the acoustic assembly 206 to deliver energy to the blade 152 portion of the end effector assembly 112, all components of the acoustic assembly 206 must be acoustically coupled to the blade 152. The distal end of the ultrasonic transducer 114 may be acoustically coupled at the surface 210 to the proximal end of the ultrasonic transmission waveguide 164 by a threaded connection such as a stud 226.

[0187] In one embodiment, the components of the acoustic assembly 206 are preferably acoustically tuned such that the length of any assembly is an integral number of one-half wavelengths (nλ/2), where the wavelength λ is the wavelength of a pre-selected or operating longitudinal vibration drive frequency f_d of the acoustic assembly 206. It is also contemplated that the acoustic assembly 206 may incorporate any suitable arrangement of acoustic elements.

[0188] In one embodiment, the blade 152 may have a length substantially equal to an integral multiple of one-half system wavelengths (nλ/2). A distal end of the blade 152 may be disposed near an antinode in order to provide the maximum longitudinal excursion of the distal end. When the transducer assembly is energized, the distal end of the blade 152 may be configured to move in the range of, for example, approximately 10 to 500 microns peak-to-peak, and preferably in the range of about 30 to 150 microns at a predetermined vibrational frequency of 55 kHz, for example.

[0189] In one embodiment, the blade 152 may be coupled to the ultrasonic transmission waveguide 164. The blade 152 and the ultrasonic transmission waveguide 164 as illustrated are formed as a single unit construction from a material suitable for transmission of ultrasonic energy. Examples of such materials include Ti6Al4V (an alloy of Titanium including Aluminum and Vanadium), Aluminum, Stainless Steel, or other suitable materials. Alternately, the blade 152 may be separable (and of differing composition) from the ultrasonic transmission waveguide 164, and coupled by, for example, a stud, weld, glue, quick connect, or other suitable known methods. The length of the ultrasonic transmission waveguide 164 may be substantially equal to an integral number of one-half wavelengths (nλ/2), for example. The ultrasonic transmission waveguide 164 may be preferably fabricated from a solid core shaft constructed out of material suitable to propagate ultrasonic energy efficiently, such as the titanium alloy discussed above (i.e., Ti6Al4V) or any suitable aluminum alloy, or other alloys, for example.

[0190] In one embodiment, the ultrasonic transmission waveguide 164 comprises a longitudinally projecting attachment post at a proximal end to couple to the surface 210 of the ultrasonic transmission waveguide 164 by a threaded connection such as the stud 226. The ultrasonic transmission waveguide 164 may include a plurality of stabilizing silicone rings or compliant supports 168 (FIG. 14) positioned at a plurality of nodes. The silicone rings 168 dampen undesirable vibration and isolate the ultrasonic energy from an outer protective sheath 166 (FIG. 14) assuring the flow of ultrasonic energy in a longitudinal direction to the distal end of the blade 152 with maximum efficiency.

[0191] In various embodiments a rotation knob may be located in a proximal end of the ultrasonic surgical instrument housing. The proximal rotation knob may be accessed easily with the thumb or index finger and substantially reduces any obstructions or “reach” issues that may be associated with a distally located rotation know. Several embodiments of ultrasonic surgical instruments comprising a proximal rotation knob are described with reference to FIGS. 28-32.

[0192] FIG. 28 is a right side view of one embodiment of an ultrasonic surgical instrument 230 comprising a proximal rotation knob 238. In the illustrated embodiment, the proximal rotation knob 238 may be located at a proximal end of the handle assembly 102. The proximal rotation knob 238 may be accessed easily with the thumb or index finger and substantially reduces any obstructions or “reach” issues that may be associated with a distally located rotation knob. The ultrasonic surgical instrument 230 may be employed in various surgical procedures including endoscopic or traditional open surgical procedures. The ultrasonic surgical instrument 230 comprises the handle assembly 102, a handle assembly 232, a proximal rotation assembly 234, a switch assembly 236, the elongated endoscopic shaft assembly 110, and the end effector assembly 112 comprising elements to mutually grasp, cut, and coagulate tubular vessels and/or tissue. The proximal rotation assembly 234 comprises a proximal rotation knob 238 that mechanically engages the ultrasonic transducer 114 housing. The ultrasonic surgical instrument 230 is adapted to receive an ultrasonic transducer 114 that is mechanically engaged to the elongated endoscopic shaft assembly 110 and portions of the end effector assembly 112. The ultrasonic transducer 114 is electrically coupled to a generator 116 via a cable 118. Although the majority of the figure drawings depict a multiple end effector assembly 112 for use in connection with endoscopic surgical procedures, the ultrasonic apparatus may be employed in more traditional open surgical procedures. For purposes herein, the ultrasonic surgical instrument 100 is described in terms of an endoscopic instrument; however, it is contemplated that an open version of the ultrasonic surgical instrument 230 also may include the same or similar operating components and features as described herein.

[0193] In one embodiment, the handle assembly 232 comprises a trigger 246 and the fixed handle 122 previously described. The fixed handle 122 is integrally associated with the handle assembly 102 and the trigger 246 is movable relative to the fixed handle 122 as explained in more detail below with respect to the operation of the ultrasonic surgical instrument 230. The fixed handle 122 and the trigger 246 comfortably interface with the user. The trigger 246 moves in direction 121A toward the fixed handle 122 when the user applies a squeezing force against the trigger 246. A spring element 182 (FIG. 14) causes the trigger 246 to move in direction 121B when the user releases the squeezing force against the trigger 246. The trigger 246 comprises an elongated trigger hook 244, which defines an aperture 248 between the elongated trigger hook 244 and the fixed handle 122. The aperture 248 is suitably sized to receive one or multiple fingers of the user therethrough. The trigger 246 also may comprise a contact portion (not shown), which may be molded over portions of the trigger 246. The overmolded contact portion provides a more comfortable contact surface for outward control of the trigger 246 in direction 121B. In one embodiment, the overmolded contact portion may be provided over a portion of the elongated trigger hook 244. For example, the overmolded contact portion may be provided over the distal and top surfaces of the inner portion of the elongated trigger hook 244 to provide cushion where it is needed by the user. The proximal surface of the elongated trigger hook 244 is not coated and remains bare substrate (e.g., polycarbonate) to enable the fingers to slide in and out of the aperture 248 more easily. In other embodiments, the elongated trigger hook 244 may incorporate overmolded contact surfaces comprising pliable, resilient, flexible polymeric materials such as polyurea elastomers made by VersaFlex, Inc., for example. The elongated trigger hook 244 may incorporate the overmolded contact surface portion to provide added comfort or a more secure grip to the user. The overmolded contact surface portion on the top portion of the interior portion of the elongated trigger hook 244 alleviates an edge pressure point on the user's finger as it enters the aperture 248. The fixed handle 122 comprises proximal contact surface 128 and a grip anchor or saddle surface 130 as previously discussed with reference to FIGS. 1-25.

[0194] In use, the proximal rotation knob 238 allows users to rotate the elongated endoscopic shaft assembly 110, control the jaws of the clamping mechanism of the end effector assembly 112, and activate the rocker switches 132 simultaneously, which creates new uses for the device for experienced users.

[0195] FIG. 29 is an enlarged right perspective view of one embodiment of the ultrasonic surgical instrument 230 shown in FIG. 28. In illustrated embodiment, the proximal rotation assembly 234 comprises a rotation knob 238 or ring formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. In one embodiment, the proximal rotation knob 238 may be located on a proximal portion of the handle assembly 102. The user may operate the proximal rotation knob 238 with either the thumb or the index finger. Using the thumb frees up the index finger to more easily and effectively access the toggle switch 252 located on the distal end of the handle assembly 102. The proximal rotation knob 238 may be constructed in multiple elements. One element may comprise a siliconized polycarbonate component overmolded with a resilient layer formed of elastomeric materials, thermoplastic rubber known as Santoprene®, other thermoplastic vulcanizates (TPVs), or elastomers, for example. The elastomeric layer provides a secure grip for the user on the outer edge of the proximal rotation knob 238, and also protrudes through an inner polycarbonate ring (not shown) to form “gripper” ribs that firmly grip the exterior housing of the ultrasonic transducer 114. Therefore, the proximal rotation knob 238 securely grips the ultrasonic transducer 114. The ultrasonic transducer 114 is securely mechanically engaged to the elongated endoscopic shaft assembly 110, such that the entire elongated endoscopic shaft assembly 110 can be rotated when the proximal knob 238 is rotated. The proximal rotation assembly 234 comprising the proximal rotation knob 238 provides a smoother, easier rotation for better control and ease of use. The proximal rotation knob 238 stabilizes the interior mechanism located in front of the ultrasonic transducer 114 to reduce any potential “rattles.” The proximal rotation knob 238 is configured to mechanically engage the housing of the ultrasonic transducer 114 such that rotation of the proximal rotation knob 238 results in rotation of the ultrasonic transducer 114 and the elongated endoscopic shaft assembly 110 in the same direction 250. The proximal rotation knob 238 comprises a plurality of flutes 240 or ribs. These flutes 240 may be engaged by a finger to rotate the rotation knob 238. The proximal rotation knob 238 may comprise “scallops” or flutes formed of flutes 240 to provide a more precise rotational grip. In one embodiment, the proximal rotation knob 238 may comprise six flutes. In other embodiments, any suitable number of flutes may be employed. The proximal rotation knob 238 may be formed of a softer polymeric material overmolded onto the hard plastic material.

[0196] The ultrasonic transducer 114 may be inserted through the proximal rotation knob 238 until the distal end of the ultrasonic transducer 114 screws in or is snapped onto the ultrasonic transmission waveguide 164 by the stud 226 (FIG. 27), for example. The elastomeric gripper ribs of the proximal rotation knob 238 provide a snug fit during insertion between the elastomeric gripper ribs and the outer diameter of the ultrasonic transducer 114. The gripper grip, however, is not tight enough to create difficulty in assembling the components. When the ultrasonic transducer 114 is threaded into the female portion of the handle 102 within the proximal opening 156, the proximal rotation knob 238 is free to rotate along with the ultrasonic transducer 114 and also is free to slide longitudinally along the longitudinal axis A along the outer surface of the ultrasonic transducer 114 as the final threads pull the ultrasonic transducer 114 forward into the elongated endoscopic shaft assembly 110. After the ultrasonic transducer 114 is completely assembled with a torque wrench, the proximal rotation knob 238 remains free to spin, gripping the ultrasonic transducer 114 and thereby rotating the entire elongated endoscopic shaft assembly 110. The gripper ribs secure the outer surface of the ultrasonic transducer 114 enough to facilitate rotation even under surgical conditions in which the assembly or the user's gloves may be wet, for example.

[0197] In one embodiment, the switch assembly 236 may be implemented as a MIN/MAX rocker-style or “toggle” switch 252. In one position, the MIN/MAX rocker-style switch (or “toggle” style) buttons create an easily accessible location for power activation with minimal (or almost no) repositioning of the hand grip, making it suitable to maintain control and keep attention focused on the surgical site (e.g., a monitor in a laparoscopic procedure). The switch assembly 236 comprises a toggle switch 252 partially located within the handle assembly 102. The switch assembly 236 comprises a rocker switch 252 implemented as a single component with a central pivot located inside the handle assembly 102, to eliminate the possibility of simultaneous activation. The rocker switch 252 may wrap around the side of the fixed handle 122 slightly to be easily accessible by variable finger lengths. The toggle switch 252 is coupled to the generator 116 to control the activation of the ultrasonic transducer 114. The toggle switch 252 comprises one or more electrical power setting switches to activate the ultrasonic transducer 114 to set one or more power settings for the ultrasonic transducer 114. In one embodiment, the toggle switch 252 comprises a first electrical contact portion 252a and a second electrical contact portion 252b to set the power setting of the ultrasonic transducer 114 between a minimum power level (e.g., MIN) and maximum power level (e.g., MAX). The first and second contact portions 252a,b of the toggle switch 252 may be overmolded with a soft polymeric material including Versaflex® TPE alloys made by GLS Corporation, for example. The overmolding portion may be useful for tactile identification or differentiation of the toggle switch 252 contact portions 252a,b from the rest of the handle assembly 102. The contact portions 252a,b may be configured to wrap around the fixed handle 122 to some extent to allow greater freedom of access to activation in awkward positions or for shorter fingers. As previously discussed, on of the contact portions 252a,b may comprise a texture or tactile surface that enables the user to differentiate between the first contact portion 252a and the second contact portion 252b. Either the first contact portion 252a or the second contact portion 252b may comprise a plurality of textured ribs 252c to allow the user to differentiate the first contact portion 252a (MAX) from the second contact portion 252b (MIN).

[0198] The toggle switch 252 may be operated by the hand of the user. The user may easily access the first and second electrical contact portions 252a,b at any point while also avoiding inadvertent or unintentional activation at any time. The toggle switch 252 may be operated by the index finger of the user to activate power to the ultrasonic assembly 114 and/or control the power level of the ultrasonic assembly 114. The index finger may be employed to activate the first contact portion 252a to turn on the ultrasonic assembly 114 to a maximum (MAX) power level. The index finger may be employed to activate the second contact portion 252b to turn on the ultrasonic assembly 114 to a minimum (MIN) power level. The first contact portion 252a or the second contact portion 252b may comprise a texture to assist the user to differentiate between them using tactile feel without looking For example, in the illustrated embodiment, the first contact portion 252a comprises a plurality of textured ribs 252c to enable the user to differentiate the first contact portion 252a (MAX) from the second contact portion 252b (MIN). Other textures or elements may be formed on either of the first or second contact portions 252a,b to enable the user to differentiate therebetween. The toggle switch 252 may be operated without the user having to look at the first or second contact portions 252a,b. This allows the user to focus entirely on the monitor view during a laparoscopic procedure. The user does not have to reposition their grip in order to operate the toggle switch 252 and can easily adjust the power ON/OFF or MIN/MAX while opening the jaws of the end effector assembly 112.

[0199] In one embodiment, the proximal rotation assembly 234 is rotatable without limitation in either direction 250 about a longitudinal axis “T” (FIG. 13). The proximal rotation assembly 234 is mechanically engaged to the housing of the ultrasonic transducer 114, which is mechanically engaged to the elongated endoscopic shaft assembly 110. The proximal rotation assembly 234 is located at a proximal portion of the handle assembly 102. The proximal rotation assembly 234 comprises internal protrusions to mechanically engage the housing of the ultrasonic transducer 114, which is mechanically engaged to the elongated endoscopic shaft assembly 110. The rotation knob 238 may be engaged by the index finger to rotate the elongated endoscopic shaft assembly 110 360° in direction 250.

[0200] In one embodiment, the ultrasonic surgical instrument 230 may be configured with ergonomic features to enable the user to easily access and operate the multiple functions and controls of the instrument. Accordingly, the index finger may be used to operate the distal rotation knob 238 located at the proximal end of the handle assembly 102. The rotation knob 238 is mechanically engaged to the hosing of the ultrasonic transducer 114, which is mechanically engaged and acoustically coupled to the ultrasonic transmission waveguide 164 (FIG. 14). Thus, the index finer can be used to rotate the rotation knob 238 to rotate shaft of the ultrasonic transmission waveguide 164 to locate the end effector assembly 112 in the proper orientation during a surgical procedure. The MIN/MAX power buttons of the rocker switch 252 are suitably located on the fixed handle 122 of the instrument 230 so that they may be operated with the index finger. Accordingly, the index finger can be used to rotate the shaft of the endoscopic portion 110 to orient the jaws of the end effector assembly 112 in a desired position and to activate the power level of the ultrasonic transducer 114.

[0201] FIGS. 30-32 illustrate one embodiment of an ultrasonic surgical instrument 260 comprising a proximal rotation assembly 262. In the illustrated embodiment, the ultrasonic surgical instrument 260 comprising the proximal rotation assembly 262 may be employed in various surgical procedures including endoscopic or traditional open surgical procedures. In one embodiment, the ultrasonic surgical instrument 260 may be configured with ergonomic features to enable the user to easily access and operate the multiple functions and controls of the instrument. The proximal rotation assembly 262 may be located on a proximal end of the handle assembly 102 and may be accessed easily with the thumb or finger (e.g., the index finger). This substantially reduces any obstructions or “reach” issues that may be associated with a rotation knob located at the distal end of the handle assembly 102. In addition, use of the thumb frees up the index finger, for example, to more easily and effectively access the toggle switch 132 located at the distal end of the handle assembly 102.

[0202] In one embodiment, the proximal rotation assembly 262 comprises a ring shaped proximal rotation knob 264. The proximal rotation knob 264 is configured to mechanically or frictionally engage the outer surface 115 of the ultrasonic transducer 114. As previously discussed, the ultrasonic transducer 114 is mechanically engaged to the elongated endoscopic shaft assembly 110. Thus, rotating the rotation knob 264 rotates the ultrasonic transducer 114 and the elongated endoscopic shaft assembly 110 in the same direction 250. The proximal rotation knob 264 comprises a plurality of flutes 266 (e.g., ribs or scallops) formed on an exterior portion 113 thereof. The flutes 266 may be engaged by the thumb or finger of the user to rotate the proximal rotation knob 264 360° in either direction 250 about the longitudinal axis “T”. The flutes 266 of the proximal rotation knob 264 also provide a precise rotational grip. In one embodiment, the rotation knob 264 may comprise any suitable number of flutes 226 to provide a precise rotational grip. The proximal rotation knob 264 also comprises a plurality of radial projections 268 formed on an interior portion 117 thereof. The radial projections 268 may be formed of or may coated with a pliable, resilient polymeric material to securely frictionally engage the outer surface 115 of the ultrasonic transducer 114. The radial projections 268 are dimensioned to form a snug or tight fit between the outer surface 115 of the ultrasonic transducer 114 and the proximal rotation knob 264. The ultrasonic transducer 114 is securely mechanically engaged to the ultrasonic transmission waveguide 164 portion of the elongated endoscopic shaft assembly 110 by the surface 210 and the stud 266 (FIG. 27). Accordingly, as the securely gripped proximal rotation knob 264 is rotated in direction 250 so are the ultrasonic transducer 114 and the entire elongated endoscopic shaft assembly 110. The proximal rotation knob 264 provides a smooth, easy rotation of the ultrasonic transducer 114 and the elongated endoscopic shaft assembly 110 using the thumb or finger, providing increased control to the surgeon. The ultrasonic transducer 114 comprises a distal rim portion 272 with a circumferential ridge 274 to engage a groove (not shown) formed within the inner wall of the proximal opening 156.

[0203] As previously discussed, in one embodiment, the proximal rotation knob 264 is securely mechanically or frictionally engaged to the outer housing of the ultrasonic transducer 114, which is mechanically engaged and acoustically coupled to the ultrasonic transmission waveguide 164 (FIG. 14). For example, during a surgical procedure either the thumb or index finger may be used to control the rotation of the ultrasonic transmission waveguide 164 shaft to locate the jaws of the end effector assembly 112 in a suitable orientation. The middle and/or the other lower fingers may be used to squeeze the trigger 120 and grasp tissue within the jaws. Once the jaws are located in the desired position and the jaws are clamped against the tissue, the index finger can be used to activate the toggle switch 132 to adjust the power level of the ultrasonic transducer 114 and treat the tissue. Once the tissue has been treated, the user the may release the trigger 120 and push outwardly in the distal direction against the elongated trigger hook with the middle and/or lower fingers to open the jaws of the end effector assembly 112. This basic procedure may be performed without the user having to adjust their grip on the handle assembly 102.

[0204] In one embodiment, the proximal rotation knob 264 may be formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. Pliable, resilient, and flexible polymeric materials provide a secure and comfortable grip for the user on the outer exterior portion of the proximal rotation knob 264.

[0205] The proximal rotation knob 264 may be provided separately as an accessory that may be packaged with the ultrasonic surgical instrument 260 but not attached thereto. The proximal rotation knob 264 may be a doughnut or ring shaped single component formed of a substantially pliable, resilient, and flexible polymeric material. The proximal rotation knob 264 may be inserted over the outer surface 115 of the ultrasonic transducer 114, e.g., handpiece HP054 or HPBLUE, both manufactured by Ethicon Endo-Surgery. The radial projections 268 or “gripper ribs” formed on the interior portion 117 of the proximal rotation knob 264 securely engage the outer surface 115 diameter of the ultrasonic transducer 114. The radial projections 268 may be formed of the same pliable, resilient, flexible polymeric material as the proximal rotation knob and define a diameter that is undersized relative to the outer surface 115 diameter of the ultrasonic transducer 114 to create a friction interference fit. The radial projections 268, however, do not engage the outer surface 115 diameter of the ultrasonic transducer 114 so tightly as to make it difficult to assemble the components.

[0206] Once the proximal rotation knob 264 is located on the outside surface 115 of the ultrasonic transducer 114, the transducer 114 is inserted through the proximal opening 156 of the instrument handle assembly 102 the surface 210 is attached to the ultrasonic transmission waveguide 164 by the stud 226 (FIG. 27). In other embodiments, the distal end of the ultrasonic transducer 114 may be snapped onto the proximal end of the ultrasonic transmission waveguide 164. Once the distal end of the ultrasonic transducer 114 is located within the proximal opening 156 of the instrument handle assembly 102, the proximal rotation knob 264 is free to rotate along with the ultrasonic transducer 114 and also is free to slide longitudinally along the longitudinal axis T along the outer surface of the ultrasonic transducer 114 as the final threads of the stud 226 pull the ultrasonic transducer 114 forward in the proximal direction towards the elongated endoscopic shaft assembly 110. After the ultrasonic transducer 114 is completely assembled with a torque wrench, the proximal rotation knob 264 remains free to rotate, gripping the ultrasonic transducer 114 and thereby rotating the entire elongated endoscopic shaft assembly 110. The radial projections 268 frictionally secure the outer surface of the ultrasonic transducer 114 with adequate force to facilitate rotation of the elongated endoscopic shaft assembly 110 even surgical conditions in which the exterior of the assembly or the surgeon's gloves may be wet. After use the proximal rotation knob 264 may be removed from the ultrasonic transducer 114 and either discarded or sterilized as described below.

[0207] FIG. 33 is a left side view of one embodiment of handle assembly 280 for an ultrasonic surgical instrument comprising both proximal and distal rotation assemblies. In one embodiment, the handle assembly 280 comprises multiple rotation controls that may be accessible in a multitude of hand positions and suitable for a multitude of hand sizes. In one embodiment, the handle assembly 280 comprises dual rotation controls comprising the distal rotation control knob 134 and the proximal rotation control knob 264, as previously described. In one embodiment, the handle assembly 280 comprises the distal rotation assembly 106 comprising the distal rotation knob 134 as previously described. In addition, the handle assembly 280 comprises the proximal rotation assembly 262 comprising the proximal rotation knob 264, as previously described.

[0208] FIG. 34 is an enlarged partial left perspective view of one embodiment of the handle assembly 280. As shown in FIG. 34, in one embodiment the proximal rotation knob 264 is ring-shaped and comprises an external portion 113 and an interior portion 117. A plurality of flutes 266 are formed on an exterior surface 276 thereof. An internal surface 270 of the proximal rotation knob 264 comprises a plurality of radial projections 268 to frictionally engage the outer contours of the handpiece assembly of the ultrasonic transducer 114. As previously discussed, the proximal rotation knob 264 may be formed of pliable, resilient, flexible polymeric materials, for example.

[0209] With reference to both FIGS. 33 and 34, the combination of dual rotation controls such as the proximal rotation assembly 262 and the distal rotation assembly 106 provide several benefits. The dual rotation controls render the handle assembly 280 better suited for users with small hands and reduce fatigue because it employs a natural movement of the thumb and/or fingers. If the finger tip rotation control of the distal rotation knob 134 is difficult for a user with small hands to reach or the hand is located in an awkward position, the proximal rotation knob 264 provides the user with the option of using the proximal rotation knob 264 with their thumb to control the rotation of the elongated endoscopic shaft assembly 110.

[0210] The proximal rotation knob 264 and the distal rotation knob 134 may be used in combination to rotate the elongated endoscopic shaft assembly 110 in opposite directions to ease stress and fatigue and also to prevent the cable 118 (FIGS. 1, 27, 28, 30) from winding around the handpiece during use when only rotating in one direction. A right handed user, for example, may employ the index finger to rotate the distal rotation knob 134 clockwise and employ the thumb to rotate the proximal rotation knob 264 counter clockwise to ease finger fatigue and prevent the cable 118 from tangling. Thus, as the user may readily switch between clockwise and counter clockwise rotation methods the cable 118 becomes less tangled.

[0211] Additional benefits of the combination of the proximal rotation assembly 262 and the distal rotation assembly 106 include simultaneous multi-function use and ease of use in multiple hand positions. The proximal rotation knob 264 enables rotation control of the end effector assembly 112 with the thumb. This may be more comfortable and may allow finer rotation control for small handed users. As previously discussed, in use, the proximal rotation knob 264 allows users to rotate the elongated endoscopic shaft assembly 110, control the jaws of the clamping mechanism of the end effector assembly 112, and activate the rocker switches 132 simultaneously, which creates new uses for the device for experienced users. Providing the combination of distal and proximal rotation control lets the user select the most suitable rotation control depending on the position of the hand, e.g., neutral, supinated, pronated, awkward. Dual rotation is also less fatiguing because the natural movement of the finger and thumb are moved in a downward motion to effect rotation of control knobs. For example, the index finger may apply a downward force against the distal rotation knob 134 to rotate the elongated endoscopic shaft assembly 110 clockwise. Counter clockwise rotation of the distal rotation knob 134 requires an upward motion of the index finger, which may be awkward and slightly more fatiguing. The thumb may apply a downward force against the proximal rotation knob 264 to rotate the elongated endoscopic shaft assembly 110 counter clockwise. Thus, counter clockwise rotation of the elongated endoscopic shaft assembly 110 mow requires a less awkward and fatiguing downward motion of the thumb motion. The dual rotation control configuration gives the user the option of selecting between a finger and a thumb to apply rotation to the elongated endoscopic shaft assembly 110, which causes less compounding fatigue on one muscle group. In either case, the user has the option of selecting the control configuration that is best suited for their physical attributes and styles.

[0212] FIG. 35 illustrates a partial cut away view of one embodiment of a handle assembly 281 for an ultrasonic surgical instrument. With reference now to FIG. 35 and FIGS. 10-12 and 14, in one embodiment, a trigger 278 actuates the yoke 170, which is mechanically engaged to the coupling elements 160 (FIG. 14) through various link members and the yoke 170. The coupling elements 160 are seated in the yoke 170 and locked in place with the pin 162 (FIG. 14) provided through an opening 171 in the yoke 170. The elongated endoscopic shaft assembly 110 is coupled to the yoke 170 by way of the coupling elements 160. The coupling elements 160 mechanically engage the hub 163 located at the proximal end of the outer tubular sheath 142. For example, the hub 163 of the outer tubular sheath 142 is retained in the yoke 170 by the pin 162. The proximal end of the reciprocating tubular actuating member 144 is mechanically engaged to the outer tubular sheath 142. Once locked into place, the yoke 170, the coupling elements 160 reciprocate within opening 296 in directions 146A,B along the longitudinal axis T to effect motion of the elongated endoscopic shaft assembly 110 in the same directions. The motion is in response to the trigger 278. Accordingly, as the trigger moves in directions 121A,B the yoke 170, the coupling elements 160, and the elongated endoscopic shaft assembly 110 move in corresponding directions 146A,B. Thus, when the trigger 278 is squeezed in direction 121A the reciprocating tubular actuating member 144 moves in direction 146A to close the jaw elements of the end effector assembly 112 in direction 148A as shown in FIGS. 10-12. The spring element 182 restores the movable trigger in direction 121B when the squeezing force is released. Accordingly, the yoke 170 and the reciprocating tubular actuating member 144 moves in direction 146B to open the jaws of the end effector assembly 112 in direction 148B as shown in FIGS. 10-12.

[0213] In the illustrated embodiment, the hub 133 is located within the first and second portions 102a,b of the handle assembly 102. A circumferential lip 344 is formed on a cylindrical sleeve portion 135 and is received within a circumferential groove 346 formed in the distal end of the handle assembly 102. The circumferential lip 344 and the circumferential groove 346 are dimensioned such that the cylindrical sleeve portion 135 is free to rotate within the circumferential groove 346. The hub 133 is free to rotate within the circumferential groove 346 when the first and second portions 102a,b of the handle assembly 102 are mated. The hub 133 is dimensioned and configured to receive the distal rotation knob 134.

[0214] In one embodiment, the trigger 278 is mechanically engaged to first and second link members 282, 284 at a movable first pivot point 288. The movable pivot point 288 is captured and moves within a first slot 294. At one end the first and second link members 282, 284 are pivotable at the first pivot point 288. At the other end of the first link member 282, the first link member is coupled to and is rotatable about a second pivot point 290. At the other end of the second link member 284, the second link member 284 is coupled to and is pivotable about a third pivot point 292. At one end the third link member 286 is coupled to the second link member 284 at the third pivot point 292. At the other end the third link member 286 is coupled to a fourth pivot 300, which is captured in and movable within a second slot 302. The yoke 170 is coupled to the third link member 286 at the fourth pivot 300. The yoke 170 is coupled to the coupling elements 160 and is part of the reciprocating yoke assembly 173. Accordingly, as the trigger 120 is squeezed in direction 121A, the first pivot point 288 moves downwardly within the first slot 294 pulling the second link member 284 and the third link member 286 downwardly. As the third link member 286 is pulled downwardly the yoke 170 is forced in direction directions 146A along the longitudinal axis T closing the jaw elements of the end effector assembly 112 in direction 148A. As the moveable trigger 120 is released, the spring element 182 forces the trigger 278 to move in direction 121B, which in turn forces the yoke to move in direction 146B along the longitudinal axis A opening the jaw elements of the end effector assembly 112 in direction 148B.

[0215] FIG. 36 is an enlarged partial view of one embodiment of the toggle switch 132 and the yoke assembly 173 within a housing portion of the handle assembly 281. The switch assembly 108 comprises the toggle switch 132 implemented as a single component with a central pivot 304 inside the handle assembly 102, to eliminate the possibility of simultaneous activation. The toggle switch 132 rotates about the central pivot 304 as the first projecting knob 132a and the second projecting knob 132b are actuated. The electrical element 172b electrically energizes the ultrasonic transducer 114 in accordance with the activation of the first or second projecting knobs 132a,b.

[0216] FIGS. 37-44 illustrate one embodiment of a handle assembly 310 for an ultrasonic surgical instrument comprising both proximal and distal rotation assemblies. In the illustrated embodiment, the handle assembly 310 comprises multiple rotation controls that may be accessible in a multitude of hand positions and for a multitude of hand sizes. In one embodiment, the handle assembly 310 comprises a housing 314 formed of a first portion 314a (not shown) and a second portion 314b. The handle assembly 310 comprises a proximal rotation assembly 312 and the distal rotation assembly 106 previously descried. The proximal rotation assembly 312 comprises a proximal rotation knob 334 and the distal rotation assembly 106 comprises the distal rotation knob 134.

[0217] In one embodiment, the handle assembly 310 comprises the distal rotation assembly 106 comprising the distal rotation knob 134 with the hub 133 and the flutes 134b as previously described. In addition, the handle assembly 310 comprises the proximal rotation assembly 312. The proximal rotation assembly 312 comprises the proximal rotation knob 334 attached to a cylindrical hub 335 and a plurality of flutes 336 formed on an exterior portion thereof. The cylindrical hub 335 comprises a circumferential lip 332 adapted and configured to engage a corresponding circumferential groove 328 formed in the housing 314. The circumferential lip 332 and the corresponding circumferential groove 328 are dimensioned to enable the cylindrical hub 335 to rotate freely within the circumferential groove 328. The cylindrical hub 335 comprises a plurality of slots 330 formed around a circumference thereof. The proximal rotation knob 334 comprises a plurality of radial projections 338 formed around a circumference thereof that correspond to the slots 330. The proximal rotation knob 334 may be formed of pliable, resilient, flexible materials. A portion of the plurality of radial projections 338 protrudes radially through the slots 330 to securely frictionally engage the outer surface of the ultrasonic transducer 114.

[0218] In one embodiment, the handle assembly 310 comprises a trigger 322 and a fixed handle 316. The fixed handle 316 is integrally associated with the handle housing 314 and the trigger 322 is movable relative to the fixed handle 316 as previously explained in detail in FIGS. 1-9 with respect to the operation of the ultrasonic surgical instrument 100. The fixed handle 316 and the trigger 322 comfortably interface with the user. The trigger 322 moves in direction 121A toward the fixed handle 316 when a squeezing force is applied against the trigger 322. A spring element 182 (FIG. 14) causes the trigger 322 to move in direction 121B and return to an original state when the user releases the squeezing force against the trigger 322.

[0219] In one embodiment, the trigger 322 comprises an elongated trigger hook 324 portion, which defines an aperture 126 between the elongated trigger hook 279 and the fixed handle 122. The aperture 126 is suitably sized to receive one or multiple fingers therethrough.

[0220] In one embodiment, the trigger 322 also may comprise a contact portion 322a molded over the substrate of the trigger 322. The overmolded portion 322a provides a more comfortable contact surface for outward control of the trigger 322 in direction 121B. In one embodiment, the overmolded portion 322a may be provided over a portion of the elongated trigger hook 324. For example, in the illustrated embodiment, the overmolded portion 322a contact surface is provided over the distal and top surfaces of the inner portion of the elongated trigger hook 324 to provide cushion where it is needed by the user. The proximal surface of the elongated trigger hook 324 is not coated and remains bare substrate (e.g., polycarbonate) to enable the fingers to slide in and out of the aperture 126 more easily.

[0221] In other embodiments, the elongated trigger hook 324 may incorporate an overmolded component formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. The elongated trigger hook 324 may incorporate the overmolded portion 322a to provide added comfort or a more secure grip to the user. The overmolded contact portion 322a formed on a top portion of the interior portion of the elongated trigger hook 324 alleviates edge pressure points on the fingers as they enters the aperture 126. The top portion of the trigger hook 324 may comprise a concave region 325 to allow additional clearance for the second projecting knob 132b (not shown).

[0222] In one embodiment, the fixed handle 322 comprises a proximal contact surface 317 and a grip anchor or saddle surface 318. The proximal contact surface 317 is a normal pistol grip handle with no rings or apertures to be received in the palm of the user. The profile curve of the proximal contact surface 317 is contoured to accommodate or receive the palm of the hand. To provide comfort and control while using the ultrasonic instrument, the profile of the proximal contact surface 317 is optimized to fit the natural anatomical contours in the valley of the center of the palm and base of the thumb. In one embodiment, the saddle surface 318 provides a grip anchor, which contributes to the stability of control of the handle assembly 310. The location of the saddle surface 318 determines the range of motion for the fingers and thumb to access the proximal rotation knob 334, the distal rotation knob 134, the elongated trigger hook 324, and the power activation toggle switch from the proximal contact surface 317 of the fixed handle 316.

[0223] A stabilization tail 320 that may be in contact with the portion of the hand located between the thumb and the index finger adds stability when the handle provides added control to the handle assembly 310. The stabilization tail 320 provides an extended return area to allow proximal weight of the ultrasonic surgical instrument to rest on top of the hand of the user. This provides a greater sense of stability, comfort, and control in the saddle surface 318 of the handle assembly 310.

[0224] FIGS. 45-52 illustrate one embodiment of the proximal rotation assembly 312 shown in FIGS. 37-44. In the illustrated embodiment, the proximal rotation assembly 312 comprises the proximal rotation knob 334 inserted over the cylindrical hub 335. The proximal rotation knob 334 comprises a plurality of radial projections 338 that are received in corresponding slots 330 formed on a proximal end of the cylindrical hub 335. The proximal rotation knob 334 defines an opening 348 to receive the distal end of the ultrasonic transducer 114. The radial projections 338 are formed of a soft polymeric material and define a diameter that is undersized relative to the outside diameter of the ultrasonic transducer 114 to create a friction interference fit when the distal end of the ultrasonic transducer 114. The polymeric radial projections 338 protrude radially into the opening 348 to form “gripper” ribs that firmly grip the exterior housing of the ultrasonic transducer 114. Therefore, the proximal rotation knob 334 securely grips the ultrasonic transducer 114.

[0225] The distal end of the cylindrical hub 335 comprises a circumferential lip 332 and a circumferential bearing surface 340. The circumferential lip engages the groove 328 formed in the housing 314 and the circumferential bearing surface 340 engages the housing 314, as shown in FIGS. 38 and 40, for example. Thus, the cylindrical hub 335 is mechanically retained within the two housing portions 314a (not shown) and 314b of the housing 314 as shown in FIGS. 37-44. The circumferential lip 332 of the cylindrical hub 335 is located or “trapped” between the first and second housing portions 314a,b and is free to rotate in place within the groove 328. The circumferential bearing surface 340 bears against interior portions of the housing 314 to assist proper rotation. Thus, the cylindrical hub 335 is free to rotate in place within the housing 314. The user engages the flutes 336 formed on the proximal rotation knob 334 with either the finger or the thumb to rotate the cylindrical hub 335 within the housing 314.

[0226] In one embodiment, the cylindrical hub 335 may be formed of a durable plastic such as polycarbonate. In one embodiment, the cylindrical hub 335 may be formed of a siliconized polycarbonate material. In one embodiment, the proximal rotation knob 334 may be formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. The proximal rotation knob 334 may be formed of elastomeric materials, thermoplastic rubber known as Santoprene®, other thermoplastic vulcanizates (TPVs), or elastomers, for example. The embodiments, however, are not limited in this context.

[0227] FIGS. 53-57 illustrate one embodiment of the distal rotation assembly 106 shown in FIGS. 37-44. In the illustrated embodiment, the distal rotation assembly 106 is formed of a hub 133 comprising a fluted rotation knob 134 formed thereon. The hub 133 comprises a cylindrical sleeve portion 135, which is received within the distal housing portion (e.g., first and second housing portions 102a,b and first and second housing portions 314a,b). A pair of openings 342 are formed in the cylindrical sleeve portion 135 to receive the pin 162 to retain the hub portion 163 of the outer tubular sheath 142 (FIG. 14). A circumferential lip 344 is formed on the cylindrical sleeve portion 135 and is received within a corresponding groove 346 formed in the distal end of the handle assembly 102. The circumferential lip 344 and the circumferential groove 346 are dimensioned such that the cylindrical sleeve portion 135 is free to rotate within the circumferential groove 346 when the first and second portions 102a,b of the handle assembly 102 are mated.

[0228] The hub 133 is located or rotatably “trapped” between the left and right housing portions 102a,b and is free to rotate in place within the groove 346. The fluted rotation knob 134 is formed over the hub 133 employing using well known overmolding techniques or other techniques. The fluted rotation knob 134 also may be mechanically or frictionally engaged with the hub 133. The flutes are defined by raised ridges or ribs 134b and concave regions 134b formed therebetween. The hub 133 may be formed of a durable plastic such as polycarbonate. In one embodiment, the hub 133 may be formed of a siliconized polycarbonate material. The fluted rotation knob 134 may be formed of a resilient, pliable polymeric material such as Santoprene or Versaflex, for example. The embodiments are not limited in this context.

[0229] Turning now to FIGS. 58-69, it has long been a challenge to create a handle design in terms of size, shape, and location of control interfaces that is “ideal” for everyone. The very large disparity of anthropometrics from 5th percentile small female to 95th percentile large male surgeon from traditionally creates ergonomic challenges for users at the extreme ends of the spectrum. Although provision of multiple different handle sizes has been considered for some time, there is a general within the hospital community to carry fewer inventories, thus there still would exist the risk that a certain size handle would not be available for a particular individual at a particular hospital. Thus, various embodiments provide a handle design for multiple instruments to more optimally ergonomically interface in terms of comfort and control for a large variety of hand sizes.

[0230] FIG. 58 is a right side perspective view of one embodiment of the handle assembly 102 for an ultrasonic surgical instrument suitable to receive a handle adapter. The handle assembly 102 comprises a trigger assembly 104, a distal rotation assembly 106, and a switch assembly 108. The handle assembly 102 comprises a trigger 120 and a fixed handle 122. The fixed handle 122 is integrally associated with the handle assembly 102 and the trigger 120 is movable relative to the fixed handle 122 as explained in more detail below with respect to the operation of the ultrasonic surgical instrument 100. The fixed handle 122 and the trigger 120 comfortably interface with the user. The fixed handle 122 comprises proximal contact surface 128 and a grip anchor or saddle surface 130. The stabilization tail 131 may be in contact with the portion of the hand located between the thumb and the index finger and adds stability to the handle assembly 102. The trigger 120 comprises the elongated trigger hook 124, which defines the aperture 126 between the elongated trigger hook 124 and the fixed handle 122. The handle assembly 102 is suitable to receive a handle adapter as described below.

[0231] FIG. 59 is a right side perspective view of one embodiment of the handle assembly 102 and one embodiment of a handle adapter 400. The handle adapter 400 comprises a body that defines an opening 402 to receive the fixed handle 122, the proximal contact surface 128, the saddle surface 130, and the stabilization tail 131. The interior of the opening 402 defines a contour that is the inverse shape of the proximal contact surface 128, the saddle surface 130, and the stabilization tail 131 such that the adapter fits snugly against the proximal contact surface 128, the saddle surface 130, and the stabilization tail 131. An external contour of the opening 402 defines a new fixed handle 122′, a proximal contact surface 128′, a saddle surface 130′, and a stabilization tail 131′ portion that is substantially similar to the proximal contact surface 128, the saddle surface 130, and the stabilization tail 131 originally formed on the fixed handle 122. The thickness or width of the handle adapter 400 is ergonomically adapted to the size of the hand of the user. The handle adapter 400 may be formed of a single-piece component and may be packaged to be used in conjunction with an ultrasonic surgical instrument that may be sized for average-to-smaller hands. The handle adapter 400 may easily be removably attached to the handle assembly 102 of the ultrasonic surgical instrument 100 to expand or enlarge the size of the grip to accommodate larger hands. Prominent graphics may be provided on the instrument package and on the handle adaptor 400 to communicate the intended use of the handle adapter 400. The overall appearance of the handle adaptor 400 makes its function readily understandable.

[0232] FIG. 60 is a right side perspective view of one embodiment of the handle assembly 102 comprising the handle adapter 400 attached thereto. In one embodiment, the handle adaptor 400 may be formed as a press-fit component that fits “like a glove” over the main grip portion of the fixed handle 122. For example, the handle adapter 400 may be configured to extend over at least a portion of a heel/bottom surface of the fixed handle 122 and/or at least a portion of the stabilization tail 131. The handle adapter 400 is frictionally held in place during use. The handle adaptor 400 is easily removable from the handle assembly 102. The handle adaptor 400 may be formed of a variety of materials including a range of elastomers with varying durometers, rigid polymers, and pliable polymers, among others. In one embodiment, the surface area of the adapter may comprise a wide range of texture and grip detailing over the contours of the geometry of the handle adapter 400. In another embodiment, the handle adapter 400 may comprise variable-size feature embedded as part of the main handle-wherein a lock/release control enables the proximal portion of the handle adapter 400 to extend or compress, to allow substantially infinite adjustment for a particular hand size.

[0233] FIGS. 61-69 illustrate one embodiment of a handle adapter 410 comprising snap-button features suitable for attaching to a handle assembly of an ultrasonic surgical instrument. The handle adapter 410 defines an opening 412 adapted and configured to receive a fixed handle portion of a handle assembly of a surgical instrument. The handle adapter 410 defines the fixed handle 122′, the proximal contact surface 128′, the saddle surface 130′, and the stabilization tail 131′ portions of the handle assembly that are more suitably ergonomically adapted to the hand of the user. Similar to FIG. 60 above, the fixed handle portion 122′ of the handle adapter 410 may be configured to extend over at least a portion of a heel/bottom surface of the fixed handle 122 and/or the stabilization tail portion 131′ of the handle adapter 410 may be configured to extend over at least a portion of the stabilization tail 131. The handle adapter 410 may be formed of a single-piece component and may be packaged to be used in conjunction with an ultrasonic surgical instrument that may be sized for average-to-smaller hands. The handle adapter 410 may be easily removably attached to the handle assembly 102 (FIGS. 58-60) of the ultrasonic surgical instrument 100, to expand the size of the grip to accommodate larger hands. Prominent graphics may be provided on the package and on the handle adaptor 410 to communicate the intended use of the handle adapter 410. The overall appearance of the handle adaptor 410 makes its function readily understandable.

[0234] In one embodiment, the handle adaptor 410 may be formed as a press-fit component that fits “like a glove” over the main grip portion of the fixed handle. The interior portion of the handle adapter 410 comprises snap button features 404 that may be received in corresponding openings (not shown) defined on the fixed handle 122 portion of the handle assembly 102 (FIGS. 58-60). The snap button features 404 mechanically attach the handle adapter 410 to the fixed handle 122 and hold the handle adapter 410 in place during use. The handle adaptor 410 is easily removably attached from the fixed handle 102 of the handle assembly 102. The handle adaptor 410 may be formed of a variety of materials including a range of elastomers with varying durometers, rigid polymers, and pliable polymers, among others. In one embodiment, the surface area of the adapter may comprise a wide range of texture and grip detailing over the contours of the geometry of the handle adapter 410. In another embodiment, the handle adapter 410 may comprise variable-size feature embedded as part of the main handle—wherein a lock/release control enables the proximal portion of the handle adapter 410 to extend or compress, to allow substantially infinite adjustment for a particular hand size.

[0235] Turning now to FIGS. 70-87, the multi-function capability of the ultrasonic surgical instrument 100, particularly the laparoscopic ultrasonic surgical instrument 100 may create certain ergonomic challenges for the user to comfortably access and operate the multiple functions and controls of the instrument. These include the ability to comfortably actuate the jaws of the clamping mechanism of the end effector assembly 112 and to activate the hand control buttons such as the toggle switch 132. The user must be able to control the opening motion in direction 148B (FIGS. 3 and 11) of the end effector assembly 112 to facilitate spreading dissection, for example. A spreading dissection using laparoscopic instruments requires a reaction surface to allow the user to manipulate the instrument in multiple directions. Using an outward movement of the thumb to oppose the “anchored” fingers provides for an adequate outward motion to accomplish this task. The ultrasonic surgical instruments previously described include a handle assembly comprising a fixed handle, either integrally formed with the handle assembly or removably attached thereto. The pistol grip incorporates a trigger that may be pushed outward with the index and middle finger while maintaining grip on the handle stock. This outward motion action, however, may create fatigue and hand strain during a spreading or fine dissection procedures. Nevertheless, this outward motion is necessary during spreading or fine dissection laparoscopic procedures. The pistol grip handle, which is preferred by many surgeons for its comfort, ease, and stability of the grip style, may not be optimal for ease of dissection. For dissections, many surgeons prefer a scissor-like loop or ring type grip. Accordingly, various embodiments described below provide an ultrasonic surgical instrument comprising a handle assembly that may be adapted and configured with a scissor-like loop or ring type grip. The scissor-like loop or ring type grip may be formed integrally with the handle assembly or may be implemented in the form of a removably attached loop adapter.

[0236] FIG. 70 illustrates one embodiment of a handle assembly 102 of an ultrasonic surgical instrument comprising a loop handle adapter assembly 418. The loop handle adapter assembly 418 comprises a loop handle adapter 420 and a resilient, pliable, and/or flexible element 428 attached thereto. The loop handle adapter 420 adapts or converts the fixed handle 122 portion of the handle assembly 102 from a conventional pistol grip to a scissor-like loop or ring type grip comprising a pair of loops defined by apertures 422. The loop handle adapter 420 facilitates the use of a more controlled manipulation of the handle assembly 102 outward motion during spreading or fine dissection laparoscopic procedures, for example. The loop handle adapter 420 is adapted and configured to removably attach to the fixed handle 122 portion of the handle assembly 102. The loop handle adapter 420 comprises one or more snap features 424 (FIG. 71) and one or more posts 426 (FIGS. 71, 77, 79) formed integrally on an interior surface 425 (FIG. 71) of the loop handle adapter 420. The one or more snap features 424 (FIGS. 71-73, 77-80) removably engage the loop handle adapter 420 to the fixed handle 122 of the handle assembly 102. The one or more posts 426 align the loop handle adapter 420 with the fixed handle 122. In one embodiment, the elongated trigger hook 124 may comprise a plurality of nubs 127 formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example.

[0237] The apertures 422 are defined by two curved elements 430a,b (430b is shown in FIGS. 71-79) and a proximal contact element 432 that are joined at a base portion 436 and at an upper saddle surface 438. The two curved elements 430a,b and the proximal contact element 432 also define a stabilization tail 434. The aperture 422 is suitable to receive the thumb of the user therethrough to enable the user to more easily and comfortably manipulate the handle assembly 102 or apply a retracting force. The user may insert the thumb through the aperture 422 and engage the proximal contact surface 128 and the saddle surface 130 of the fixed handle 122, which remains exposed to engage the hand. The loop handle adapter 420 also may be employed as an adapter for larger handed users who wish to use the handle assembly 102 with a conventional pistol grip. The proximal contact element 432, the upper saddle surface 438, and the stabilization tail 434 provide a larger span to accommodate a larger hand to more comfortably reach to controls such as the trigger 120 and the switch assembly 108. The loop handle adapter 420 also defines a lower saddle surface 442 to accommodate the lower base portion of the thumb.

[0238] FIGS. 71-80 illustrate one embodiment of the loop handle assembly 418. As illustrated, the loop handle assembly 418 comprises a loop handle adapter 420 coupled to a flexible element 428. The loop handle adapter 420 comprises the two curved elements 430a,b that define a radius “r” relative to an axis 435. The two curved elements 430a,b join the proximal contact element 432 to define the aperture 422, the upper saddle surface 438, the stabilization tail 434, and the lower saddle surface 442. Functionally, the aperture 422 enables the user to employ the thumb to assist in the manipulation of the handle assembly 102. The upper saddle surface 438 and the stabilization tail 434 perform the same functions as discussed above with reference to FIGS. 25 and 26. The post 426 may be formed near a base portion 436 of the loop handle adapter 420 and the two snap features 424 that snap into corresponding indentations or openings (not shown) formed on the sides of the fixed handle 122 may be formed near the saddle surface 130 region of the handle assembly 102. This allows a quick secure removably mounted connection that can be easily removed if necessary. The flexible element 428 comprises a plurality of ribs 440 to provide resilience and to reduce the pressure to the sides of the thumb. The flexible element 428 also comprises a lower saddle surface 442a to engage the lower saddle surface 442 of the loop handle adapter 420. The loop handle adapter 420 also provides a contact surface 444 to engage the thumb of the user. In one embodiment, the resilient, pliable, flexible element 428 may be attached or molded to the proximal contact element 432 of the loop handle adapter 420. The loop handle adapter 420 may be formed as a single component with the flexible element 428 or they may be formed as separate components. The loop handle adapter 420 may be formed of a durable plastic such as polycarbonate and the flexible element 428 may be formed of softer pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. The flexible element 428 may be molded over the loop handle adapter 420 or may be formed separately and then attached thereto.

[0239] FIGS. 81-82 illustrate left and front perspective views of one embodiment of the loop handle adapter 420. FIG. 82 shows an internal body portion 432a of the proximal contact element 432 to receive the flexible element 428.

[0240] FIGS. 83-87 illustrate one embodiment of a flexible element 428 portion of the loop handle assembly 418 shown in FIGS. 71-80. The flexible element 428 may be formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. The flexible element 428 is formed of a single element comprises a contact surface 444, a plurality of ribs 440, and a saddle surface contact surface 442b adapted to engage the lower saddle potion 442 of the loop handle adapter 420 shown in FIGS. 81-82. The saddle surface 442a may be engaged by the thumb or hand of the user. The flexible element 428 also comprises a channel 446 to receive the internal body portion 432a of the proximal contact element 432. As shown, the channel 446 expands to a larger channel 448 to accommodate the lower saddle surface 442 of the of the loop handle adapter 420.

[0241] Turning now to FIGS. 88-90, several factors can be applied to assess the viability of the ergonomics of a particular design for a medical instrument. Aside from comfort, one objective factor is the ability to control the working end of the handle assembly 102 with a suitable degree of control needed to accomplish a surgical task with ease. To the extent that this control is achieved emanates first from the inherent stability of the handle assembly 102 in the hand of the user, and second from the ease of the finer motions required to manipulate the specific instrument controls. Design efforts include balancing the ability to achieve overall stability in the hand while facilitating appropriate access to the fine controls.

[0242] In various embodiments, the handle assembly 102 may be stabilized by adapting a variety of pistol grips. The various embodiments of the pistol grips provide several points of fixation on the hand:

[0243] (1) a squeezing force between the thumb and index fingers resting in the web of the joint;

[0244] (2) a grasping force between the thumb and index finger; and

[0245] (3) a gripping force between the fingers and the palm while activating the trigger 120.

[0246] There exists optimal locations between the various controls on the distal end of the handle assembly 102 that may be employed as points of fixation. These include locations between the distal rotation knob 134, the toggle switch 132, the trigger 120, and the saddle surface 130, which rests on the thumb/index web of the joint of the hand. Some embodiments vary the width of the fixed handle 122 portion to accommodate various hand sizes including varying the basic distance between the saddle surface 130 and the front controls. Other embodiments vary the length of the fixed handle 122 to situate the end of the fixed handle 122 against the palm. Still, other embodiments vary the angle of the fixed handle 122.

[0247] FIG. 88 illustrates one embodiment of a handle assembly 350 comprising a curved stability projection 352 (e.g., bump) formed at the rear or proximal location of the fixed handle 122. The curved stability projection 352 provides an intimate contact surface between the fixed handle 122 and the length of the palm of the hand to stabilize the handle assembly 350. One point of fixation may be achieved by locating the saddle surface 130 of the handle assembly 350 at the thumb/index finger web of the joint of the hand as described above. A second area of fixation is achieved by locating the curved stability projection 352 at the rear of the fixed handle 122 to achieve contact between the handle assembly 350 and the center of the palm of the hand. In this manner, a large area of contact is achieved in the center of the palm instead of a small area at the base 354 of the fixed handle 122. The saddle surface 130 of the handle assembly 350 is maintained without varying the optimum grip span 356. The contact area may be achieved regardless of hand size because of the broad curve of the curved stability projection 352. Providing two fixation points mechanically prevents the distal tip of the instrument from rotating about the saddle surface 130 with little actual applied hand force, thus freeing up the digits of the hand to actuate the finer controls such as the distal rotation knob 134, the toggle switch 132, and the trigger 120, for example. The curved stability projection 352 may be formed integral to the length of the fixed handle 122 of the handle assembly 352, or may be formed by adding a softer, more conforming material to the fixed handle 122.

[0248] FIGS. 89 and 90 illustrate one embodiment of a handle assembly 360 comprising protrusions 362 formed on both sides of the fixed handle 122. The protrusions 362 provide additional fixation points and ergonomic benefits to handle assemblies described herein. In one embodiment, the protrusions 362 enable additional control of the handle assembly 360 during dissection or other types of surgical procedures. Some users may experience fatigue and reduced control when using certain ultrasonic surgical instruments while operating the instrument. One factor that may lead to fatigue and reduced control is pinching the fixed handle 122 between the thumb and index finger of the user while pushing outward on the elongated trigger hook 124 with their other fingers. Accordingly, the ear-like protrusions 362 attached or formed to both sides of the handle assembly 360 provide an edge or surface contact area for the user to engage with the thumb. The protrusions 362 stabilize of the handle assembly 360 during surgical procedures, such as dissecting, and alleviate some of the fatigue due to squeezing the handle assembly 360 between the thumb and index finger. The protrusions 362 may comprise a ridge 364 to allow for the thumb to counteract the extension force in direction 366 with and opposing surface instead of relying on friction and compression from squeezing the thumb and the index finger. The protrusion may be textured or overmolded with a compliant material to improve the grip and feel when the user is wearing surgical gloves. It also may be contoured so as not to create any sharp or uncomfortable edges that the thumb or index finger can rest against.

[0249] Various embodiments comprising blades and clamp arm assemblies comprising proximal tissue pad segments, distal tissue pad segments, and tissue pad insert segments have been described. The pivotal movement of the clamp arm assemblies with respect to the blades may be affected by the provision of a pair of pivot points on the clamp arm portion of the clamp arm assembly that interfaces with an ultrasonic surgical instrument via weld pin fastening or other fastening means. The tissue pad segments may be attached to the clamp arm by mechanical means including, for example, rivets, glues, adhesives, epoxies, press fitting or any other fastening means known in the art. Furthermore, the tissue pad segments may be removably attached to the clamp arm by any known means.

[0250] In various embodiments, the clamp arm may comprise a T-shaped slot for accepting a T-shaped flange of a proximal tissue pad segment, a distal tissue pad segment and a tissue pad insert segment. In various embodiments, a single unitary tissue pad assembly may comprise the proximal tissue pad segment, the distal tissue pad segment and the tissue pad insert segment, and further comprise a T-shaped flange for reception in a T-shaped slot in the clamp arm assembly. Additional configurations including dove tailed-shaped slots and wedge-shaped flanges are contemplated. As would be appreciated by those skilled in the art, flanges and corresponding slots have alternative shapes and sizes to removably secure the tissue pad segments to the clamp arm.

[0251] A method for replacing the proximal tissue pad segment, the distal tissue pad segment and/or the tissue pad insert segment include one or more of the steps of: a) disengaging the clamp arm assembly from the ultrasonic surgical instrument; b) removing at least one of the tissue pad segments from the clamp arm; c) inserting at least one new or reconditioned tissue pad segment into the clamp arm; and d) engaging the clamp arm assembly with the ultrasonic surgical instrument. In this removal and replacement process, the new or reconditioned proximal tissue pad segment, distal tissue pad segment and tissue pad insert segment may be multiple separate segments or of unitary construction.

[0252] Another method for replacing the proximal tissue pad segment, the distal tissue pad segment and/or the tissue pad insert segment include one or more of the steps of: a) opening flanges on the clamp arm; b) removing at least one of the tissue pad segments from the clamp arm; c) inserting at least one new or reconditioned tissue pad segment into the clamp arm; and d) closing flanges on the clamp arm. In this removal and replacement process, the new or reconditioned proximal tissue pad segment, distal tissue pad segment and tissue pad insert segment may be multiple separate segments or of unitary construction.

[0253] Preferably, the various embodiments described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. This can be done by any number of ways known to those skilled in the art including beta or gamma radiation, ethylene oxide sterilization, and/or steam, for example. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK® bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons sterilization. The sterilization kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility.

[0254] Although various embodiments have been described herein, many modifications and variations to those embodiments may be implemented. For example, different types of end effectors may be employed. In addition, combinations of the described embodiments may be used. For example, a concave blade tip may be coated with a hydrophobic material. Also, where materials are disclosed for certain components, other materials may be used. The foregoing description and following claims are intended to cover all such modification and variations.

[0255] Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.