Hand held surgical device for manipulating an internal magnet assembly within a patient

[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/453,824 filed Mar. 17, 2011, the contents of which are incorporated herein by reference in their entirety.

[0002] Ethicon Endo-Surgery, Inc., an Ohio corporation, and Southwestern Medical Center at Dallas having a place of business at 5323 Harry Hines Blvd. Dallas, Tex. 75390, are parties to a Joint Research Agreement.

[0003] Ethicon Endo-Surgery, Inc., an Ohio corporation, and The University of Texas at Arlington having a place of business at 710 S. Nedderman Drive Arlington, Tex. 76019, are parties to a Joint Research Agreement.

[0004] i. Field of the Invention

[0005] The present application relates to methods and devices for minimally invasive therapeutic, diagnostic, or surgical procedures and, more particularly, to magnetic guidance systems for use in minimally invasive procedures.

[0006] ii. Description of the Related Art

[0007] In a minimally invasive therapeutic, diagnostic, and surgical procedures, such as laparoscopic surgery, a surgeon may place one or more small ports into a patient's abdomen to gain access into the abdominal cavity of the patient. A surgeon may use, for example, a port for insufflating the abdominal cavity to create space, a port for introducing a laparoscope for viewing, and a number of other ports for introducing surgical instruments for operating on tissue. Other minimally invasive procedures include natural orifice transluminal endoscopic surgery (NOTES) wherein surgical instruments and viewing devices are introduced into a patient's body through, for example, the mouth, nose, or rectum. The benefits of minimally invasive procedures compared to open surgery procedures for treating certain types of wounds and diseases are now well-known to include faster recovery time and less pain for the patient, better outcomes, and lower overall costs.

[0008] Magnetic anchoring and guidance systems (MAGS) have been developed for use in minimally invasive procedures. MAGS include an internal device attached in some manner to a surgical instrument, laparoscope or other camera or viewing device, and an external hand held device for controlling the movement of the internal device. Each of the external and internal devices has magnets which are magnetically coupled to each other across, for example, a patient's abdominal wall. In the current systems, the external magnet may be adjusted by varying the height of the external magnet.

[0009] The foregoing discussion is intended only to illustrate various aspects of the related art in the field of the invention at the time, and should not be taken as a disavowal of claim scope.

[0010] A device is described herein for manipulating a magnetic coupling force across tissue based on the monitored coupling force generated between the external and internal magnets. In one embodiment, the device includes a magnetic field source assembly that comprises a first magnetic field source for providing a magnetic field across tissue. The first magnetic field provides a magnetic coupling force between the first magnetic field source and an object that provides a second magnetic field. The device also includes a positioning assembly operatively connected to the magnetic field force assembly for adjusting the position of the first magnetic field source, and a magnetic coupling force monitor.

[0011] The device may further include an outer housing that contains the magnetic field source assembly and preferably also contains at least a portion of the positioning assembly. In certain embodiments, the positioning assembly includes a driver for adjusting the elevational position of the magnetic field force assembly within the outer housing, and an actuator for moving the driver.

[0012] In several embodiments, the magnetic field source assembly may comprise a first magnetic field source for providing, in use, a magnetic field across tissue, the first magnetic field providing a magnetic coupling force between the first magnetic field source and an object providing a second magnetic field source; a positioning assembly operatively connected to the magnetic field force assembly for adjusting the position of the first magnetic field source, the positioning assembly having a driver for adjusting the elevational position of the magnetic field force assembly and an actuator for moving the driver; and a magnetic coupling force monitor.

[0013] In certain embodiments of the device, the object is structured for positioning in use on an internal site of a patient and has associated therewith a second magnetic field source for forming with the first magnetic field source the magnetic coupling force across tissue.

[0014] The magnetic field source assembly may further include a magnet housing and a magnet support. In certain embodiments, first magnetic field source may have at least one magnet and preferably two magnets, held by the magnet support and suspended within the magnet housing. A bracket member may be provided for connecting the magnet housing to the driver of the positioning assembly. Movement of the driver will adjust the elevational position of the magnet housing within the outer housing.

[0015] In one embodiment, the actuator of the positioning assembly may be a manually controllable actuator operatively connected to the driver. For example, the manually controllable actuator may be a rotatable knob mounted on a proximal end of the driver which, when turned, rotates the driver to adjust the elevational position of the magnet housing.

[0016] Some embodiments of the device may include a spring assembly for suspending the magnet and magnet support within the magnet housing. The spring assembly may include a spring mounted at its distal end on the magnet support and operatively suspended at its proximal end from the magnet housing, and biased toward the proximal end thereof.

[0017] In certain embodiments, the spring assembly may also include a retainer connected through the bracket to the magnet housing and a suspension member connected to the magnet support. The retainer is preferably structured to secure thereto the proximal end of the spring and the suspension member is preferably structured to secure thereto the distal end of the spring.

[0018] In certain embodiments, the suspension member is operatively connected to the magnetic coupling force monitor. The magnet housing may define a first window therethrough and the outer housing may define a second window therethrough aligned with the first window. In certain embodiments, the magnetic coupling force monitor may comprise an indicator tab that extends from the suspension element through, and is movable up and down, in a proximal or distal direction, within, each of the first and second windows. Indicia may be marked on an exterior surface of the outer housing adjacent the second window indicative of the coupling force experienced by the magnet.

[0019] Some embodiments of the actuator may include a gear set operatively connected to the driver and a motor operatively connected to the gear set for motorized control of the driver.

[0020] The device may be provided with an electromechanical automatically adjusting closed loop system for controlling the magnetic coupling force based on the sensed force between the external and internal magnetic field sources.

[0021] Certain embodiments of the magnetic coupling force monitor may include a sensor positioned at a distal end of the magnet support on which the magnet support rests. The sensor is preferably calibrated to sense any change in the force exerted on the sensor. A communication circuit is preferably provided from the sensor to the motor to control the operation of the motor in response to the sensed changes in force.

[0022] The magnetic coupling force monitor may further include a transducer positioned on the floor of the magnet housing for measuring changes in the magnetic coupling force between the magnet and the object and transmitting signals representative of the measured change in the magnetic coupling force; a control unit for receiving the signals from the transducer; and, a processor in communication with the control unit for converting the received signals to output signals for signaling the motor to adjust the elevation of the magnet housing until a predetermined magnetic coupling force is measured by the transducer.

[0023] The positioning assembly may also include a fail-safe mechanism for preventing travel of the driver outside of predetermined limits. The fail-safe mechanism may be an optical sensor having a channel, a light source for sending a beam of light across the channel, a light blocking member structured for passage through the channel and operatively connected to the magnetic field source assembly, and a receiver for detecting the presence or absence of the beam of light across the channel and for signaling the presence or absence of the beam of light to the motor to stop the motor when the beam of light is blocked by the blocking member.

[0024] The fail-safe mechanism may alternatively be a set of trip switches for signaling the motor to stop when the driver travels outside of the predetermined limit.

[0042] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate various embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

[0043] Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. It will be understood by those skilled in the art, however, that the embodiments may be practiced without such specific details. In other instances, well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described in the specification. Those of ordinary skill in the art will understand that the embodiments described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments, the scope of which is defined solely by the appended claims.

[0044] In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.

[0045] Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment”, or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” or “in an embodiment”, or the like, in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features structures, or characteristics of one or more other embodiments without limitation.

[0046] It will be appreciated that the terms “proximal” and “distal” may be used throughout the specification with reference to a clinician manipulating one end of an instrument used to treat a patient. The term “proximal” refers to the portion of the instrument closest to the clinician and the term “distal” refers to the portion located farthest from the clinician. It will be further appreciated that for conciseness and clarity, spatial terms such as “vertical,” “horizontal,” “up,” and “down” may be used herein with respect to the illustrated embodiments. However, surgical instruments may be used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[0047] As used herein, the term “elevational position” with respect to one or more components means the distance of such component or components above a floor or ground or bottom position of another component or reference point without regard to the spatial orientation of the respective components.

[0048] As used herein, the term “biocompatible” includes any material that is compatible with the living tissues and system(s) of a patient by not being substantially toxic or injurious and not known to cause immunological rejection. “Biocompatibility” includes the tendency of a material to be biocompatible.

[0049] As used herein, the term “operatively connected” with respect to two or more components, means that operation of, movement of, or some action of one component brings about, directly or indirectly, an operation, movement or reaction in the other component or components. Components that are operatively connected may be directly connected, may be indirectly connected to each other with one or more additional components interposed between the two, or may not be connected at all, but within a position such that the operation of, movement of, or action of one component effects an operation, movement, or reaction in the other component in a causal manner.

[0050] As used herein, the term “operatively suspended” with respect to two or more components, means that one component may directly suspended from another component or may be indirectly suspended from another component with one or more additional components interposed between the two.

[0051] As used herein, the term “patient” refers to any human or animal on which a suturing procedure may be performed. As used herein, the term “internal site” of a patient means a lumen, body cavity or other location in a patient's body including, without limitation, sites accessible through natural orifices or through incisions.

[0052] The manipulation device 10 is structured to manipulate a magnetic coupling force across living tissue 200 between objects having, or associated with, magnetic fields. The manipulation device 10 generally includes a magnetic field source assembly 24, a positioning assembly operatively connected to the magnetic field source assembly, and a magnetic coupling force monitor.

[0053] The magnetic field source assembly 24 includes a first, or external, magnetic field source that provides a magnetic field across tissue 200. In MAGS applications, there is an object 210, as shown in FIG. 1, positioned in use on an internal site of a patient, across the tissue 200 (e.g., the abdominal wall or other tissue barrier between the inside and the outside of the patient) from the manipulation device 10. The internal object 210 is itself or is operatively connected to another component that is a source of a second, or internal, magnetic field. The first, or external, magnetic field of the magnetic field source assembly 24 and the second, or internal, magnetic field source create a magnetic coupling force wherein the internal object 210 is magnetically coupled across the tissue 200 to the magnetic field source of the manipulation device 10.

[0054] Lateral movement of the manipulation device 10 over the external surface of the tissue 200 causes a similar lateral movement of the internal object 210 on the internal surface of the tissue. If the magnetic coupling force is too strong, however, lateral movement may be difficult due to the resistance to movement by the strongly attracted, magnetically coupled objects, or may induce tissue trauma due to the high coupling force. Based on the monitored force generated between the external and internal magnetic field sources, the manipulation device 10 described herein enables control of the magnetic coupling force to maintain the force at a level that is strong enough to hold the internal object 210 while allowing lateral movement of the manipulation device 10 and the internal object, but without inducing excess tissue trauma.

[0055] The control that the manipulation device 10 exercises over the magnetic coupling force may be manual or automatic. In each embodiment, the manipulation device 10 may include a magnetic field source assembly 24 that is suspended within an outer container 12 that provides an outer housing for the device 10. The magnetic assembly 24 is raised and lowered, either automatically in response to a sensor, or manually in response to a clinician's control, to adjust the power that the external magnetic field source exerts over the internal object and its associated internal magnetic field source. Adjusting the power of the external magnetic field adjusts the magnetic coupling force between the external magnetic assembly and the internal object.

[0056] Referring to FIGS. 3A-C, the magnetic field source assembly 24 includes generally a magnet housing 26 having side walls 26a and a bottom cross bar 26b, at least one or more, and preferably two magnets 28, and a magnet support 36. The magnet support 36 includes front and rear panels 48 and a midsection 50 that separates the magnets 28. The support 36 is fixed to each magnet 28 by any suitable engagement members. For example, referring to the embodiment of FIG. 4, raised rails 58 are positioned in complementary engagement with recessed tracks 60 formed on at least a portion of facing surfaces of the front and rear panels 48 and magnets 28, respectively. Those skilled in the art will appreciate that the magnets 28 may have raised surfaces and the support 36 may have complementary recessed surfaces to secure the magnets 28 within support 36. Other suitable complementary engagement surfaces or other suitable fixation devices to secure the magnets 28 to the support 36 will suffice.

[0057] Spacers 66 extend from the support panels 48 to maintain alignment of the magnets 28 within support 36.

[0058] The midsection 50 of support 36 is structured in certain embodiments to define a lower channel 52 between the lower ends of magnets 28 forming an open space between the cross-bar 26b, midsection 50, and the interior facing sides 62 of magnets 28. The midsection 50 also defines an upper channel 54 between the top ends of magnets 28 forming an open space between the top of midsection 50 and the interior facing sides 62 of magnets 28. As shown in FIG. 3, a well 64 may be formed in the top of midsection 50.

[0059] FIGS. 5-8 illustrate an embodiment of the magnetic assembly 24 having a bracket 40 connected to magnet housing 26. The bracket 40 shown in the figures includes a top section 80 and a central post 78 that extends partially into the channel 54 between magnets 28. Extending downwardly from post 78 on opposing sides of post 78 are bracket legs 82. A flange 68 extends from each side of the top section 80 of bracket 40 to seat in a chamfer on the upper edge of magnet housing 26 to hold bracket 40 in position relative to magnet housing 26. Pins 86 protrude laterally from each side of central leg 82 through pin holes 90 in magnet housing side walls 26a to further fix bracket 40 to magnet housing 26.

[0060] The positioning assembly may include a drive shaft 88 which extends through a bore 84 in top 80 of bracket 40. In this embodiment, bore 84 and drive shaft 88 are preferably threaded so that actuation of the drive shaft 88 carries bracket 40, and with it, magnet housing 26 up and down within the open gap 46 in outer housing 12 between the top of the magnet assembly 24 and the bottom of shaft head 74.

[0061] In certain embodiments, the position of the magnet housing 26 may be adjusted manually by the surgeon or clinician. A spring loaded scale may be used to float the magnets 28 within the housing 26 and to monitor the magnetic coupling force. Referring to FIGS. 7 and 8A, B, a retainer 94 sits in and is fixedly attached to well 64 of magnet support 36. A spring 92 is positioned on the boss of retainer 94 that extends upwardly into channel 54 between magnets 28. The top of spring 92 is press fit onto a retainer 96 that is suspended from pins 98. Pins 98 protrude laterally from each side of retainer 96 and extend into and through pin holes 76 in bracket legs 82 of bracket 40 and magnet housing 26 to fix retainer 96 to bracket 40 and magnet housing 26. The magnets 28 and magnet support 36 are thus suspended by spring 92 within magnet housing 26, allowing the magnets 28 to float above the floor of outer housing 12. The magnet support 36 and magnets 28 are not fixedly attached to magnet housing 26 or to bracket 40, but move up and down within magnet housing 26. Support 36 and magnets 28 are dimensioned to be smaller than magnetic housing 26 to fit within magnet housing 26 such that a gap 44 is created between the floor of outer housing 12 and the bottom surface of magnets 28 and the magnets 28 move freely without resistance from the interior walls of magnet housing 26.

[0062] Referring to FIG. 1, the manipulation device 10 includes outer housing 12 having a top cover 14. The sides of cover 14 include openings 20 to expose a knob 16. The cover 14 may be connected to outer housing 12 in any suitable manner, such as with pins or screws 38 or a similar fastener, through pin holes or threaded bores 70, shown in FIG. 6. As shown in FIG. 6, outer housing 12 includes cut-out sections 72 on the top edge to accommodate portions of knob 16. The knob 16 may be turned in a clockwise or a counter clockwise direction by placing a hand on the top of cover 14 and turning knob 16 with the thumb of the hand through openings 20. Knob 16 may include ridges 18 or any suitable textured surface along its circumference to facilitate tactile control over the movement of knob 16. Knob 16 is operatively connected to drive shaft 88 by a shaft head 74 that is sized to engage a complementary mating surface on knob 16.

[0063] A magnetic coupling force monitor is provided in one embodiment of the manipulation device 10 by means of an indicator bar 32 that extends laterally from retainer 94 through windows 100 and 30 in magnet housing 26 and outer housing 12, respectively. Indicia 34 in the form of markings may be positioned on the outer surface of outer housing 12 adjacent window 30 to represent the position of magnets 28 within magnet housing 26 and outer housing 12. The indicia are calibrated to represent predetermined loads on the magnets 28, representative of the magnetic coupling force across a patient's tissue between the external magnets 28 and one or more internal magnets associated with an internal object. For example, the force of gravity on the external magnets pulling the magnets 28 toward the floor of magnet housing 26 is zeroed out so that the force reflected by the indicia 34 represent only the magnetic coupling force. A force that could cause trauma to the tissue might be indicated by one of the lower markings or the lowest marking whereas a force that would be insufficient to hold the internal object in place might be indicated by one of the higher markings or the highest marking.

[0064] The clinician may observe the level of the magnetic coupling force by the position of the indicator bar 32 with respect to the markings 34. If the level of the coupling force is too high or too low, the clinician will adjust the knob 16 in a clockwise or counter clockwise direction to raise or lower the magnet housing 26 within the outer housing 12. As the elevational position of magnet housing 26 within outer housing 12 is changed up or down, the elevational position of magnets 28 changes up or down as well, subject to deviations within magnet housing 26 due to the magnetic coupling force exerted on magnets 28. Because of the suspension of the magnet support 36 and magnets 28 within magnet housing 26 and the clearance or gap 44 between the bottom of the magnets and the floor of the outer housing 12, the magnet support 36 and magnets 28 float within housing 26, so the only force measured is the magnetic coupling force of the magnets 28. The gap 44 may be relatively small, for example, about 5 mm, but must allow enough space so that the magnets 28 are free to move in response to the magnetic attraction from the second magnetic field source associated with the internal object in the patient. The spring 92 is biased toward the retainer 96, so, after accounting for gravity, the magnetic coupling force is the force pulling the magnets 28 downwardly, in the distal direction.

[0065] In certain embodiments, the positioning assembly may be automatic. In certain automated embodiments, as shown for example in FIGS. 9 through 11 and 13, the positioning assembly includes a shaft 88, preferably a screw drive, a drive gear 102, and a pinion gear 104. The pinion gear 104 is attached to the drive gear 102. A motor 106 drives the pinion gear 104 which drives the drive gear 102, which turns the shaft 88 to raise and lower the magnetic field source assembly 24. The drive gear 102 is attached to shaft 88 and is supported on thrust bearings 142. The shaft 88 is attached to bracket 40, as described above. In the automated embodiment, the bracket 40 is attached to the magnet housing 26 as described above, so turning shaft 88 raises and lowers the magnet housing 26 within outer housing 12. Whether the magnet housing 26 is raised or lowered, the magnet set still floats within the magnet housing 26 so the magnet 28 can respond to any magnetic pull exerted by the internal magnetic field source within the patient.

[0066] In the automated embodiments, as shown for example, in FIGS. 10, 13 and 14, a sensor 116 is positioned within the magnet housing 26, fixed to cross-bar 26b of the housing 26 in channel 54. The sensor 116 may be, for example, a transducer, a piezoelectric film sensor, or a load cell. The bottom surface of mid section 50 of magnet support 36 rests on the sensor 116. In use, the magnetic force of the internal magnetic field source attracts the magnets 28 in the external manipulation device 10. The magnetic coupling force pulls the magnets 28 against the sensor 116. The sensor 116 senses the force and communicates the sensed force to a control unit 120. Magnetic field lines are established by the magnetic field between the external and internal magnets, pulling the magnets in the magnet housing 26 down, toward the internal magnets on the object within the patient. As the downward pull increases, it pulls the magnetic support 36 harder against the sensor 116, causing the sensor 116 to measure and register a greater force against it. The sensor 116 signals the calculated force back to the control unit 120 wirelessly or via circuitry, such as wire 154 or 114. The sensor 116 is adjusted to have a zero point accounting for gravity plus the weight of the magnet housing 26, magnets 28, and magnet support 36.

[0067] Those skilled in the art will appreciate that other types of sensors may be used. A LCD screen may be provided to show the force generation between the internal and external magnets.

[0068] If sensor 116 is a load cell type of sensor, for example, it feeds the load signal to a signal conditioner. The load cell 116 is acted upon by the attractive forces between the internal and the external magnets. The load cell 116 strains internally and the resulting strain is measured in terms of electrical resistance, using current provided by any suitable power supply. The signal conditioner, which may be contained within the control unit 120, amplifies the signal from the load cell and then a suitable algorithm may be used to calculate the actual force which is then used to drive the motor 106 at a calculated speed and duration to adjust the force.

[0069] The signal is sent by the sensor 116 to the control unit 120 which is equipped with a receiver to receive the signals and where software analyzes the received signals, and sends output signals to instruct the motor 106, such as a stepper type motor, to drive the drive shaft 88, which moves the magnet housing 26 up or down sufficiently to match a predetermined force. When the predetermined force is sensed by sensor 116, the sensed signals are communicated to the control unit 120 which, as before, instructs the motor 106 to stop. The continuous monitoring in use of the magnetic coupling force provides an automatic closed loop feedback system to control the magnetic coupling force. The power supply and control unit 120 may be on any suitable printed circuit board and packaged within the outer housing 12 of the manipulation device 10. FIG. 12 shows a schematic of the power supply 118 to a transducer 116 and the signals to and from the control unit 120.

[0070] The predetermined force will be the minimum force that necessary to attract and accurately control the internal object carried by the internal magnet. The internal magnet must be held with enough magnetic force to prevent it from falling away from the internal body wall. The maximum amount of force would be less than a force that compresses or squeezes the tissue enough to cause tissue trauma. The surgeon has to be able to move the external magnet relatively easily across the patient's body to control the internal magnet without so much drag that movement is difficult or would cause tissue trauma.

[0071] The device 10 preferably includes a fail safe mechanism to prevent the motor 106 from moving the magnet housing 26 up or down too far. The device 10 may, for example, include an optical sensor 108, shown in FIGS. 9-11. The optical sensor 108 has a slot 132 through at least a portion thereof dividing the sensor into two parts, a light source portion 136 and a receiver portion 134. A light emitting diode (LED) resides in light source portion 136 of the optical sensor 108 and a receiver resides in the receiver portion 134. Light is generated inside the optical sensor 108 by the LED and beamed across the slot 132 through a light path 138 to the receiver portion 134. Pin connectors 112 from the optical sensor 108 plug into the circuit board 150, or wires may go to a printed circuit board which contains the hardware for running the sensor 116 and power sensors. A flag 110 has one end attached to the bracket 40 so that it moves up and down with the magnet housing 26 and has a second end having a top cross bar 130 that passes through the slot 132 of the optical sensor 108 as the flag moves up and down. A post 140 joining the first end to second end defines an open section between the two ends. When the flag 110 is positioned such that the top cross bar 130 of the second end blocks the path 138 for the beam of light from the LED to the receiver, the signals to the software on the circuit board 150 through connectors 112 or wires are interrupted causing the motor 106 to stop, thereby stopping the downward movement of the drive shaft 88 and the magnet housing 26. The magnet housing 26 is prevented from pressing against the bottom of the outer housing 12. When the flag 110 is positioned such that the top cross bar 130 of the second end is above the path 138 of the beam of light, the beam of light passes through the opening in the flag to the receiver in the receiver portion 134 of the optical sensor 108, which in turn signals the motor 106 through the circuit board 150 to drive the magnet housing 26 up or down.

[0072] After the motor 106 stops because the beam of light is blocked, the motor 106 will start again only when the sensor 116 signals that the force against the sensor 116 has been reduced. If the magnetic pull on the magnets 28 is reduced, the sensor 116 will sense the change and signal the control unit 120. The software logic will restart the motor 106 to allow the drive shaft 88 to move the magnet housing 26 up. The movement of the magnet housing 26 brings the flag 110 up with it, moving the top cross bar 130 of the second end above the light path and opening in the light path. If the magnet housing 26 rises too far, the first end of the flag will block the light path and in turn cause the motor 106 to stop. The magnet housing 26 is prevented from going up too far against the top of the outer housing 12.

[0073] The optical sensor 108 is fixed to a spacer piece and sits in a fixed position within a pocket in the outer housing 12 above the magnet housing 26. Those skilled in the art will recognize that other types of optical sensors and other types of fail safe mechanisms, including but not limited to trip switches, may be used.

[0074] Another embodiment of the automated manipulation device is shown in FIGS. 15 and 16. The motor 106′ of the positioning assembly in this embodiment is positioned beside the magnet housing 26 rather than above it, as shown in FIGS. 9-11. The motor 106′ is connected by a shaft 104′ to a pinion gear 102′ which turns a ring gear 152. A screw drive 88′ is operatively connected to the ring gear 152.

[0075] A sensor 116′, such as a piezo electric pressure sensitive film, is positioned on the floor of the outer housing 12′ beneath the magnet housing 26′. The sensor 116′ is electrically connected to a printed circuit board 120′ by wire 154. The circuit board 120′ may utilize a programmable controller (e.g., EPROM) to analyze signals from the sensor 116′, in the manner generally described above. The circuit board 120′ is also electrically connected to a pressure transducer 160 positioned beneath the cover 14′ of the outer housing 12′. In order to isolate the force applied by the clinician on the cover 14′ of outer housing 12′ from that of the magnetic coupling force between the external magnet 28 on the bottom of the outer housing 12′ and the internal magnet, the cover 14′ is supported by suspension springs 162. Changes in the force exerted on suspension springs 162 are read by a pressure transducer 160. As shown in FIG. 16, the cover 14′ fits in a cut-out portion on the top edge of outer housing 12′ and rests on suspension springs 162. The cover 14′ compresses springs 162 which are electrically connected to the pressure transducer 160. The load signal from the suspension springs 162 is analyzed so that the amount of load induced by the clinician is subtracted out from the load induced by the magnetic coupling force.

[0076] The embodiments of the devices described herein may be introduced inside a patient using minimally invasive or open surgical techniques. In some instances it may be advantageous to introduce the devices inside the patient using a combination of minimally invasive and open surgical techniques. Minimally invasive techniques may provide more accurate and effective access to the treatment region for diagnostic and treatment procedures. To reach internal treatment regions within the patient, the devices described herein may be inserted through natural openings of the body such as the mouth, nose, anus, and/or vagina, for example. Minimally invasive procedures performed by the introduction of various medical devices into the patient through a natural opening of the patient are known in the art as NOTES™ procedures. Some portions of the devices may be introduced to the tissue treatment region percutaneously or through small-keyhole-incisions.

[0077] Endoscopic minimally invasive surgical and diagnostic medical procedures are used to evaluate and treat internal organs by inserting a small tube into the body. The endoscope may have a rigid or a flexible tube. A flexible endoscope may be introduced either through a natural body opening (e.g., mouth, nose, anus, and/or vagina) or via a trocar through a relatively small-keyhole-incision incisions (usually 0.5-2.5 cm). The endoscope can be used to observe surface conditions of internal organs, including abnormal or diseased tissue such as lesions and other surface conditions and capture images for visual inspection and photography. The endoscope may be adapted and configured with working channels for introducing medical instruments to the treatment region for taking biopsies, retrieving foreign objects, and/or performing surgical procedures.

[0078] All materials used that are in contact with a patient are preferably made of biocompatible materials.

[0079] Preferably, the various embodiments of the devices 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. 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. The radiation 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. Other sterilization techniques can be done by any number of ways known to those skilled in the art including beta or gamma radiation, ethylene oxide, and/or steam.

[0080] Although the various embodiments of the devices have been described herein in connection with certain disclosed embodiments, many modifications and variations to those embodiments may be implemented. For example, different types of end effectors may be employed. 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.

[0081] 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.