Electrical ablation devices

[0001] Electrical ablation has been employed in medicine for the removal and treatment of a variety of abnormal tissues or growths, such as cancers or tumors. Electrical ablation may be used to treat benign prostatic hyperplasia (BPH), restricted gastric tissue, menorrhagia, and to remove adipose tissue. Other uses include removal of excess skin following bariatric surgery. Tumors in solid organs, such as the liver or lungs, may be treated or destroyed using electric direct current (DC) pulses. The abnormal tissue may be removed or treated with energy delivered by electrodes attached to therapy probes. The electrodes are positioned proximate or in contact with the diseased tissue and then energized by a variety of energy sources.

[0002] Menorrhagia is a medical condition that describes heavy and prolonged menstrual bleeding. While there are many potential causes for menorrhagia, the most common include hormone (estrogen and progesterone) imbalance, pelvic inflammatory disease, uterine fibroids, and infection. Current treatments for menorrhagia include iron supplements, prostaglandin inhibitors, oral contraceptives, and in severe cases—endometrial ablation and hysterectomy. Endometrial ablation involves introducing a conforming bipolar electrode into the uterine cavity, insufflation of the uterine cavity with CO₂ (to check for cavity integrity), and then application of bipolar RF energy to the uterine wall for 90 seconds or more. An alternative to RF ablation is ultrasonic ablation.

[0003] Bariatric surgery remains a popular and successful option to assist morbidly obese patients. The procedure substantially reduces the patient's body mass index and resolves many associated comorbidities of obesity. One of the potential problems associated with bariatric surgery is the excess skin remaining after the patient has lost substantial weight. The effects of bariatric surgery occur so quickly and with such an impact that the body loses weight at a much faster rate than it can reduce the excess skin previously needed for the larger body. Many patients who are self-conscious of their appearance will consult with cosmetic surgeons following the bariatric procedure to investigate options for having the excess skin surgically removed.

[0004] While current methods and devices used in electrical ablation are effective, one drawback with conventional electrical ablation therapy is the resulting permanent damage that may occur to the tissue. This may be particularly true with uterine tissue, where conventional ablation therapy could cause permanent damage and potentially may result in complications with becoming pregnant. Other drawbacks of conventional ablation therapy are cost, lengthy recovery periods, and it can be extraordinarily painful.

[0005] Accordingly, there remains a need for improved electrical ablation methods and devices. There is also a need to provide improved electrical ablation therapies over time.

[0037] Various embodiments are described to provide an overall understanding 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, in whole or in part, with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the claims.

[0038] It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician manipulating one end of an instrument that protrudes out of a natural orifice (or opening) of the patient. The term “proximal” refers to the portion of the instrument closest to the clinician and the term “distal” refers to the portion located furthest 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 drawings. However, surgical instruments may be used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[0039] The electrical ablation devices comprise electrodes that can be positioned inside a patient proximal to a treatment region (e.g., target site or worksite) where there is evidence of abnormal tissue growth. The electrodes comprise an electrically conductive portion (e.g., medical grade stainless steel) and are coupled to an energy source. Once the electrodes are positioned proximal to the treatment region, an energizing potential is applied to the electrodes to deliver electric current to the treatment region to remove the abnormal tissue. The electric current is supplied by an external energy source having a control unit or generator. The energizing potential (and the resulting electric current) may be characterized by a particular waveform in terms of frequency, amplitude, pulse width, and polarity. Depending on the diagnostic or therapeutic treatment to be rendered, the electrode may be configured as either an anode (−) or a cathode (−) or may comprise a plurality of electrodes with at least one configured as an anode (+) and the at least one another one configured as the cathode (−). Regardless of the initial configuration, the polarity of the electrodes may be reversed by reversing the polarity of the output of the energy source.

[0040] The energy source generates an electric field having a suitable characteristic waveform output in terms of frequency, amplitude, pulse width, and polarity. Depending on the diagnostic or therapeutic treatment to be rendered, the therapy probes may comprise one electrode containing both a cathode and an anode or may contain a plurality of electrodes with at least one serving as a cathode and at least one serving as an anode. The electrodes may be energized with DC voltages and conduct currents at various frequencies, amplitudes, pulse widths, and polarities. The electrodes also may be energized with time-varying voltages and currents at amplitudes and frequencies suitable for rendering the desired therapy. A suitable energy source may comprise an electrical waveform generator adapted to deliver DC and/or time-varying energizing potentials characterized by frequency, amplitude, pulse width, and/or polarity to the electrodes. The electric current flows between the electrodes and through the diseased tissue proportionally to the potential (e.g., voltage) applied to the electrodes. In one embodiment, the energy source may comprise a wireless transmitter to deliver energy to the electrodes via one or more antennas.

[0041] The various embodiments of the electrical ablation devices described hereinbelow utilize electroporation or electropermeabilization techniques to apply external electric fields (electric potentials) to cell membranes to significantly increase the electrical conductivity and permeability of the plasma in the cell membranes. Irreversible electroporation (IRE) is the process of killing cells by applying large destabilizing electrical potentials across the cell membranes for a long period of time. IRE provides an effective method for destroying cells while avoiding some of the negative complications of heat-inducing therapies. Namely, IRE destroys cells without the use of heat and does not destroy cellular support structure or regional vasculature. Large destabilizing IRE electric potentials may be in the range of about several hundred to about several thousand volts applied across biological membranes over a distance of about several millimeters, for example, for a relatively long period of time. The destabilizing electric potential forms pores in the cell membrane when the potential across the cell membrane exceeds its dielectric strength causing the cell to die by processes known as apoptosis and/or necrosis. Embodiments of the electrical therapy devices may be employed in the treatment of cancer by destroying live abnormal (e.g., cancerous) tissue in-vivo through the delivery of destabilizing electric potential energy to diseased tissue to quickly create cell necrosis and ablation in the cells of tumors, masses, lesions, and other abnormal growths.

[0042] FIG. 1 illustrates one embodiment of an electrical ablation device 100 shown in use. In one embodiment, the electrical ablation device 100 may be used in treatment of abnormal tissues or growths, such as cancers or tumors, formed in or on solid organs, BPH, and restricted gastric tissue using IRE energy. In other embodiments, electrical ablation treatment may be applied using other forms of electrical energy, such as those described herein. In the illustrated embodiment, the electrical ablation device 100 is shown disposed between a hollow body lumen and a solid organ. In one embodiment, the electrical ablation device 100 comprises a proximal end 102 configured for attachment through the wall of a hollow body lumen and a distal end 103 configured for attachment to abnormal tissues or growths, such as cancers or tumors, formed in a solid organ. The proximal end 102 may be attached to tissue that is endoscopically, laparoscopically, percutaneously, or transcutaneously accessible. In one embodiment, the proximal end 102 may be attached through a hollow body lumen that is endoscopically, laparoscopically, percutaneously, or transcutaneously accessible. Examples of a hollow body lumen include, for example, the esophagus, the stomach, the intestines, the colon, and may include the peritoneal cavity. In one embodiment, the proximal end 102 may be attached through the body percutaneously or transcutaneously—through the patient's skin—such that the proximal end 102 may be coupled to the energy source 119 externally and the electrical ablation device 100 may be energized from outside the patient's body. In the embodiment illustrated in FIG. 1, the electrical ablation device 100 is disposed between the stomach 108 and the liver 112. The proximal end 102 is disposed through the stomach 108 and the distal end 103 is disposed through a tumor 110 formed in the liver 112. An electrode 104 at the distal end 103 is positioned through the liver 112 and the tumor 110. The proximal end 102 of the electrical ablation device 100 may be attached to the wall 118 (FIG. 2) of the stomach 108 and the distal end 103 of the electrical ablation device 100 may be attached to the liver 112.

[0043] FIG. 2 is a partial cross-sectional view of a wall 118 of a hollow body lumen comprising the proximal end 102 of the electrical ablation device 100 attached therethrough. In the embodiment illustrated in FIG. 2, the proximal end 102 of the electrical ablation device 100 is attached through the wall 118 of the stomach 108. Referring to FIGS. 1 and 2, the proximal end 102 of the electrical ablation device 100 comprises a connector 114 and a fastener 116, which is inserted through the wall 118 of the stomach 108 and is secured thereto. In one embodiment, the connector 114 and the fastener 116 may be inserted through the body percutaneously or transcutaneously. For example, the connector 114 and the fastener 116 may be inserted through the abdominal wall and may be secured thereto. The connector 114 may be formed as a semi-permanent port. The fastener 116 comprises first and second flanges 122a, 122b connected by a hollow shaft 130 defining a longitudinal opening. The flanges 122a, b provide for the transmural attachment of the connector 114 through the wall 118 of the stomach 108 and seal the opening through the wall 118 of the stomach 108 where the shaft 130 is received. A first cable 106 is received through the longitudinal opening in the shaft 130. The cable 106 may comprise one or more electrically conductive wires electrically coupled to the connector 114 to provide electrical communication through the wall 118 of the stomach 108. In the embodiment illustrated in FIG. 1, the connector 114 is coupled to a corresponding mating female plug 115 located inside the stomach 108. The plug 115 is coupled to an energy source 119 via a second cable 117, which also may comprise one or more electrically conductive wires. The cable 117 may be introduced into the stomach 108 through the access channel or working channel of a flexible endoscope, an overtube, or though a small—keyhole—incision in the abdomen.

[0044] FIG. 19 illustrates one embodiment of the electrical ablation device 100 shown in use percutaneously, through the patient's skin. In one embodiment, the connector 114 and the fastener 116 are inserted through the body percutaneously or transcutaneously. As illustrated in FIG. 19, for example, the connector 114 and the fastener 116 are be inserted through the abdominal wall 109 and may be secured thereto with the first and second flanges 122a, 122b connected by the hollow shaft 130. The flanges 122a, b provide for the transmural attachment of the connector 114 through the abdominal wall 109 and seal the opening where the shaft 130 is received. The plug 115 is coupled to the connector 114 one end and to the energy source 119 on another end by the second cable 117, which also may comprise one or more electrically conductive wires.

[0045] Referring back to FIGS. 1 and 2, in one embodiment, the connector 114 may be attached to the wall 118 of the stomach 108 using a variety of fasteners. The connector 114 opens to the inside of the stomach 108 and the fastener 116 is used to attach the connector 114 to the wall 118 of the stomach 108. The energy source 119 is coupled to the connector 114 via the plug 115. Electrical energy generated by the energy source 119 are communicated by the cable 117 and the connector 114 through the wall 118 of the stomach 108. The electrical energy is communicated by the cable 106 to the electrode 104. As described in more detail with reference to FIG. 20, in one embodiment the electrical energy is communicated to the electrode 104 wirelessly by way of one or more antennas.

[0046] Referring to FIG. 1, in one embodiment, the electrode 104 may be attached to the tumor 110 and/or the liver 112 using a variety of fasteners. The electrode 104 is located approximately in the center of the tumor 110. In one embodiment, the electrode 104 may be configured as an anode (+) coupled to a positive terminal of the energy source 119. A second electrode may be configured as a cathode (−) coupled to a negative terminal of the energy source 119 to form a conductive return path or surface and may be located in the stomach 108 or elsewhere. It will be appreciated that the electrode 104 may be configured either as the anode (+) or the cathode (−) and the polarity of the electrode 104 may be reversed by reversing the output of the energy source 119. In one embodiment, the second electrode may be an electrically conductive balloon (not shown) located in the stomach 108 or other internal body lumen. The first and second electrodes may be inserted inside the patient's body using laparoscopic or endoscopic minimally invasive surgical techniques.

[0047] FIG. 3 illustrates one embodiment of the connector 114 configured for attachment through the wall 118 of a hollow body lumen. In the embodiment illustrated in FIG. 3, the connector 114 comprises a body 120 and the flange 122a. In one embodiment, the first flange 122a comprises one or more openings 124 for receiving sutures or tags for attaching the connector 114 to the wall 118 of the stomach 108 (both shown in FIG. 2). Although not shown in FIG. 3, the second flange 122b may comprise similar openings for receiving sutures or tags for attaching the connector 114 to the wall 118 of the stomach 108. The connector 114 comprises one or more terminals 128a, 128b, for example, to receive a corresponding female plug (e.g., plug 115 shown in FIG. 1) configured to connect to the first and second terminals 128a, 128b. First ends of the one or more electrically conductive wires disposed in the cable 106 are connected to the one or more terminals 128a, b. The body 120 also includes a first and second recesses 126a, 126b (126b not shown) for receiving corresponding tabs formed on a mating female plug portion configured to electrically coupled to the connector 114. The body is formed of an electrically insulative material such as medical grade polyester, for example, to electrically isolate the one or more terminals 128a, b from the wall 118 of the stomach 108.

[0048] FIG. 4 is a cross-sectional view of one embodiment of the electrical ablation device 100 shown in use in treatment of abnormal tissues or growths, such as cancers or tumors, formed in solid organs. In the embodiment illustrated in FIG. 4, the electrode 104 is embedded into the tumor 110 formed in the liver 112. The distal end 103 of the electrical ablation device 100 comprises a connector 134 adapted to couple to the cable 106. The electrode 104 is adapted to embed into the liver 112 and the tumor 110. The electrode 104 comprises a tapered body for easy insertion into solid body organs. In one embodiment, the electrode 104 may be formed in the shape of a needle electrode. Ridges 105 may be formed on an outer surface of the tapered body of the electrode 104 to allow for penetration attachment of the electrode 104 to tissue. The electrode 104 comprises at least one electrically conductive portion that is formed of or coated with an electrically conductive material such as medical grade stainless steel, for example.

[0049] FIG. 5 is a cross-sectional view of one embodiment of the electrical ablation device 100 shown in use in treatment of abnormal tissues or growths, such as cancers or tumors, formed in solid organs. In the embodiment illustrated in FIG. 5, an electrode 136 located at the distal end 103 of the electrical ablation device 100 is embedded into the tumor 110 formed in the liver 112. The distal end 103 of the electrical ablation device 100 comprises a connector 134 adapted to couple to the cable 106. The electrode 136 is adapted to embed into the liver 112 and the tumor 110. In the illustrated embodiment, the electrode 136 has a helical body (e.g., corkscrew) to penetrate and attach the electrode 136 into the liver 112 and the tumor 110. The electrode 136 comprises at least one electrically conductive portion formed of or coated with an electrically conductive material such as medical grade stainless steel, for example. In one embodiment, the electrode 136 may be configured as an anode (+) coupled to a positive terminal of the energy source 119. A second electrode may be configured as a cathode (−) coupled to a negative terminal of the energy source 119 to form a conductive return path or surface and may be located in the stomach 108 or elsewhere. It will be appreciated that the electrode 136 may be configured either as the anode (+) or the cathode (−) and the polarity of the electrode 136 may be reversed by reversing the output of the energy source 119. In one embodiment, the second electrode may be an electrically conductive balloon (not shown) located in the stomach 108 or other internal body lumen. The first and second electrodes may be inserted inside the patient's body using laparoscopic or endoscopic minimally invasive surgical techniques.

[0050] Referring to FIGS. 1-5, in one embodiment, the connector 114 and either one of the electrodes 104, 134 may be introduced into a hollow body lumen via a flexible endoscope using translumenal endoscopic access techniques. For convenience and brevity, the following process is described with reference only to the electrode 104 shown in FIGS. 1 and 4; however, those skilled in the art will appreciate that these techniques may be used in regards to the electrode 136 shown in FIG. 5 as well. A flexible endoscope is introduced into a natural body orifice such as the mouth, anus, or vagina. For example, the flexible endoscope may be introduced into the stomach 108 trans-orally. The cable 106 and the electrode 104 may be introduced into the stomach 108 through the working channel of the endoscope. An opening is formed through the wall 118 of the stomach 108 using translumenal access techniques, described in more detail below. The cable 106 and the electrode 104 are fed through the opening in the wall 118. The electrode 104 is inserted into the liver 112 and the tumor 110 and is secured or attached therein by the ridges 105 formed on the electrode 104. If the electrode 136 were being used, the helical body of the electrode 136 serves to penetrate and retain the electrode 136 in the liver 112 and the tumor 110. As shown in FIG. 2, the connector 114 is then attached to the wall 118 of the stomach 108 with sutures or tags inserted through the one or more openings 124 formed in the flanges 122a, b. Once the connector 114 is attached to the wall 118 of the stomach 108, the plug 115 and cable 117 may be inserted trans-orally through a working channel of the endoscope. The plug 115 is electrically coupled to the connector 114 inside the stomach 108. The plug 115 includes corresponding female receptors to receive the one or more terminals 128a, 128b and form an electrical connection. The first and second recesses 126a (FIG. 3), 126b (126b not shown) formed in the body 120 receive corresponding tabs formed on the mating female plug 115 portion to removably attach the plug 115 to the connector 114. The proximal end of the cable 117 is connected to the energy source 119 outside the patient's body. The electrical ablation therapy is then applied to the tumor 110.

[0051] Once the electrical ablation device 100 is positioned and the electrical connections are completed, the tumor 110 may be treated with electrical ablation energy supplied by the energy source 119. The electrical ablation energy may be delivered in many forms, as described in more detail below. Following the electrical ablation therapy, the plug 115 and the cable 117 are removed from the patient after disconnecting the plug 115 from the connector 114. If subsequent electrical ablation therapy is necessary to completely ablate the tumor 110, the plug 115 and the cable 117 are reinserted into the patient, the plug 115 is connected to the connector 114 and electrical ablation therapy is reinitiated. The tumor 110 may be monitored over time (e.g., days, weeks, or months) to observe shrinkage. The electrical ablation therapy may be repeated until the tumor 110 disappears. The electrical ablation device 100 remains inside the patient until the treatment of the tumor 110 is completed.

[0052] The electrical ablation device 100 is driven with electrical ablation energy supplied by the energy source 119 shown in FIG. 1. The input to the energy source 119 is connected to a commercial power supply by way of a plug (not shown). The output of the energy source 119 is coupled to the electrodes (e.g., electrode 104 or electrode 136) and energized with electrical ablation energy suitable to ablate abnormal (e.g., cancerous) tissues and destroy the tumor 110, for example. The energy source 119 may be configured to produce electrical ablation energy in various forms, as described in more detail below.

[0053] In one embodiment, the energy source 119 may be configured to produce pulsed or cyclical electrical ablation signals to electrically ablate abnormal tissue with the electrical ablation device 100. In one embodiment, a timing circuit may be used to interrupt the output of the energy source 119 and generate a pulsed output signal. The timing circuit may comprise one or more suitable switching elements to produce the pulsed output signal. For example, the energy source 119 may produce a series of n pulses (where n is any integer) suitable to treat the tumor 110 when the pulsed energy is applied to the electrodes (e.g., electrode 104 or electrode 136). The pulses may have a fixed or variable pulse width and may be delivered at any suitable frequency.

[0054] In one embodiment, the energy source 119 may be configured to produce electrical output waveforms at predetermined frequencies, amplitudes, polarities, and/or pulse widths to electrically ablate abnormal tissue with the electrical ablation device 100. When the electrical output waveforms are applied to the electrodes (e.g., electrode 104 or electrode 136), the resulting electric potentials cause currents to flow through the distal end of the electrodes to destroy abnormal tissue such as the tumor 110.

[0055] In one embodiment, the energy source 119 may be configured to produce radio frequency (RF) waveforms at predetermined frequencies, amplitudes, polarities, and pulse widths to electrically ablate abnormal tissue with the electrical ablation device 100. The energy source 119 may comprise a commercially available conventional, bipolar/monopolar electrosurgical RF generator such as Model Number ICC 350, available from Erbe, GmbH.

[0056] In one embodiment, the energy source 119 may be configured to produce irreversible electroporation (IRE) energy in the form of bipolar/monopolar pulsed DC output signals to electrically ablate abnormal tissue with the electrical ablation device 100. The energy source 119 may comprise a commercially available conventional, bipolar/monopolar Pulsed DC generator such as Model Number ECM 830, available from BTX Molecular Delivery Systems Boston, Mass. In bipolar mode a first electrode (e.g., electrode 104 or electrode 136) may be electrically coupled to a first polarity and a second electrode may be electrically coupled to a second (e.g., opposite) polarity. Bipolar/monopolar pulsed DC output signals (e.g., DC pulses) may be produced at a variety of frequencies, amplitudes, pulse widths, and polarities. For example, the energy source 119 may be configured to produce DC pulses at frequencies in the range of about 1 Hz to about 1000 Hz, amplitudes in the range of about ±100 to about ±3000 VDC, and pulse widths (e.g., pulse durations) in the range of about 1 μs to about 100 ms to electrically ablate the tumor 110. The polarity of the energy delivered to the electrodes (e.g., electrode 104 or electrode 136) may be reversed during the electrical ablation therapy. For example, the polarity of the DC pulses initially delivered at amplitudes in the range of about +100 to about +3000 VDC may be reversed to amplitudes of about −100 to about −3000 VDC. Preferably, the tumor 110 may be electrically ablated with DC pulses at frequencies of about 10 Hz to about 100 Hz, amplitudes in the range of about +700 to about +1500 VDC, and pulse widths of about 10 μs to about 50 μs. The IRE energy also may be used for the treatment of BPH and restricted gastric tissue.

[0057] In one embodiment, the energy source 119 may energize the electrode 104 through a wired or a wireless connection. In a wired connection, the energy source 119 is coupled to the electrode by way of one or more electrically conductive wires through the cable 106. As previously discussed, the cable 106 may connected to the connector 114, which may be inserted transmurally through a hollow body lumen, such as the wall 118 of the stomach 108, or percutaneously through the abdominal wall 109. In a wireless connection, the energy source 119 may be coupled to the electrode 104 by way of one or more antennas, thus eliminating the need to perforate the hollow body lumen or the patient's skin. In a wireless embodiment, the cable 106 may be replaced by an antenna 904 as shown in FIG. 19, for example. The antenna 904 is coupled to the electrode by an electrically conductive wire.

[0058] FIG. 6 illustrates one embodiment of an electrical ablation device 200 shown in use. In one embodiment, the electrical ablation device 200 may be used in treatment of abnormal tissues or growths, such as cancers or tumors, formed in or on solid organs, BPH, and restricted gastric tissue using IRE energy. In other embodiments, electrical ablation treatment may be applied using other forms of electrical energy, such as those described herein. In one embodiment, the electrical ablation device 200 comprises the connector 114 at the proximal end 102 and an electrode assembly 204 at the distal end 103. As previously discussed, the connector 114 is configured for attachment through the wall 118 of a hollow body lumen such as the stomach 108 to couple the electrical ablation device 200 to the energy source 119. The electrode assembly 204 is configured to attach to solid organ such as the liver 112 and electrically ablate abnormal tissues or growths such as the tumor 110 formed in the liver 112. As illustrated in FIG. 6, the connector 114 is attached to the wall 118 of the stomach 108 and the electrode assembly 204 is positioned on exterior surfaces of the liver 112 proximal to the tumor 110. The tumor 110 may be electrically ablated by the electrical ablation device 200 with electrical ablation energy supplied by the energy source 119.

[0059] The proximal end 102 of the electrical ablation device 200 is attached to the stomach 108 via the connector 114. As previously discussed, the connector 114 is attached to the wall 118 of the stomach 108 with sutures or tags inserted through the one or more openings 124 formed in the flanges 122a, b of the connector 114 as shown in FIG. 2. The connector 114 receives the corresponding mating female plug 115 inside the stomach 108 to electrically couple the energy source 119 to the electrical ablation device 200.

[0060] The distal end 103 of the electrical ablation device 200 is attached to the liver 112 via the electrode assembly 204. In one embodiment, the electrode assembly 204 comprises first and second plate electrodes 204a, 204b configured as electrodes and a center post 204c extending therebetween. The first and second plate electrodes 204a, b each comprise openings to receive the center post 204c. The center post 204c is inserted through the tumor 110 and through the openings formed in the first and second plate electrodes 204a, b. The first and second plate electrodes 204a, b are positioned opposite each other on outer surfaces of the liver 112. The first and second plate electrodes 204a, b are slidably movable along an outer surface of the center post 204c. Thus, the distance D (shown in FIGS. 7A and 7C) between the first and second plate electrodes 204a, b may be adjusted according to the size of the liver 112. In the illustrated embodiment, the first plate electrode 204a is located above the tumor 110 and the second plate electrode 204b is located below the tumor 110. Once positioned, the first and second plate electrodes 204a, b may be adjusted to slightly compress the liver 112. The first and second plate electrodes 204a, b each comprises at least one electrically conductive portion that is formed of or coated with an electrically conductive material such as medical grade stainless steel, for example, and are electrically coupled to respective first and second electrically conductive wires of the cable 106 to deliver electrical ablation energy to the tumor 110 from the energy source 119. The center post 204c is formed of an electrically insulative material such as medical grade polyester, for example, to electrically isolate the center post 204c from the first and second plate electrodes 204a, b. In one embodiment the first plate electrode 204a may be configured as the anode (+) electrode coupled to the positive terminal of the energy source 119 and the second plate electrode 204b may be configured as the cathode (−) electrode coupled to the negative terminal of the energy source 119. It will be appreciated that the polarity of the first and second plate electrodes 204a, b may be reversed such that the first plate electrode 204a is configured as the cathode (−) electrode and the second plate electrode 204b is configured as the anode (+) electrode by reversing the output polarity of the energy source 119.

[0061] In one embodiment, electrical ablation device 200 including the first and second plate electrodes 204a, b may be introduced to the treatment site (e.g., the tumor 110) endoscopically, laparoscopically, or through various translumenal access techniques. As previously discussed, a flexible endoscope may be introduced into the stomach 108 trans-orally and the cable 106 may be fed through the access or working channel of the endoscope. The cable 106 and the electrode 104 are initially placed in the stomach 108. The wall 118 of the stomach 108 is perforated using translumenal access techniques. The cable 106 and the electrode assembly 204 are advanced through the trans-mural opening and the electrode assembly 204 is attached to the liver 112. The plug 115 and the cable 117 are then inserted trans-orally through the working channel of the endoscope. The plug 115 at the distal end of the cable 117 is electrically coupled to the connector 114 inside the stomach 108. The proximal end of the cable 117 is connected to the energy source 119 outside the patient's body. The tumor 110 is then treated with electrical ablation energy supplied by the energy source 119. After the electrical ablation therapy is completed, the plug 115 may be removed from the connector 114 and the plug 115 and the cable 117 removed from inside the patient. The plug 115 and the cable 117 may be reinserted into the patient for subsequent electrical ablation therapy. The tumor 110 may be monitored over time (e.g., days, weeks, or months) to observe shrinkage. The electrical ablation therapy may be repeated until the tumor 110 disappears. The electrical ablation device 200 remains inside the patient until the tumor 110 is completely ablated. It will be appreciated that the electrode assembly 204 may be repositioned to treat tumors that are larger than the surface area of the first and second plate electrodes 204a, b. In various other embodiments, the first and second plate electrodes 204a, b of the electrical ablation device 200 may be coupled to the energy source 119 percutaneously through the abdominal wall 109 (FIG. 19) or wirelessly by replacing the cable 106 with the antenna 904 (FIG. 20). The antenna 904 is coupled to the first plate electrode 204a by a first electrically conductive wire and the antenna 904 is coupled to the second plate electrode 204b by a second electrically conductive wire.

[0062] FIGS. 7A and 7B are side views of one embodiment of the electrical ablation device 200 shown in use in treatment of a tumor formed in a solid organ using IRE energy. As shown in FIG. 7A, the electrical ablation device 200 is attached to the liver 112. The first and second plate electrodes 204a, b are placed above and below the tumor 110 on the outer surface of the liver 112. In FIG. 7B, the first and second plate electrodes 204a, b have been slidably moved toward each other along the outer surface of the center post 204c to compress the liver 112 to a distance D₁, which is less than the distance D shown in FIG. 7A. Compression of the liver 112 helps to concentrate the energy delivered to the tumor 110 as well as reduce the voltage required to ablate the tumor 110. Furthermore a more homogeneous electric field can be applied with using the parallel plates configuration of the first and second plate electrodes 204a, b. The first and second plate electrodes 204a, b are electrically coupled to the energy source 119 (FIG. 6) via the cable 106. The output of the energy source 119 is set to create a voltage difference between the first and second plate electrodes 204a, b that is high enough to produce an electric field, represented by iso-lines 210, sufficient to electrically ablate the tumor 110. The potential energy level of the electric field may be in the order of about 1e5 volts/meter. The potential energy level is sufficient to destroy the tumor 110 and the tissue surrounding the tumor 110.

[0063] FIG. 7C is a cross-sectional view of one embodiment of the electrical ablation device 200. The first and second plate electrodes 204a, b are separated by a distance D, which is adjustable by slidably moving the first and second plate electrodes 204a, b along an outer surface 214 of the center post 204c. First and second conductors 212a, 212b are electrically connected to the respective first and second plate electrodes 204a, b. The first and second conductors 212a, b are provided through respective openings 216a, 216b formed through the center post 204c. The first and second conductors 212a, b are contained in respective insulative sheathes 220a, b and are housed within an electrically insulative outer sheath 218 of the cable 106. In the illustrated embodiment, the first and second conductors 212a, b are coupled to the respective positive (+) and negative (−) terminals of the energy source 119 (FIG. 6) through the connector 114 (FIG. 6), for example. In other embodiments, the polarity of the first and second conductors 212a, b may be reversed. The first and second plate electrodes 204a, b may be locked into position against the center post 204c once adequate compression has been applied to the liver 112 as shown in FIG. 7B. In one embodiment, the first and second plate electrodes 204a, b are maintained at a desired distance D from each other by frictionally engaging the outer surface 214 of the center post 204c with the inner surfaces defined by the openings 222a, 222b. In other embodiments, various features may be provided on the outer surface 214 of the center post 204c and the inner surface defined by the openings 222a, 222b in the respective first and second plate electrodes 204a, b to lock the first and second plate electrodes 204a, b at a desired distance D from each other. These features may include corresponding male and female threaded surfaces, ratcheting surfaces, and grooves with detents, for example.

[0064] With reference to FIGS. 6 and 7A-C, the tumor 110 may be electrically ablated by applying IRE energy to the first and second plate electrodes 204a, b of the electrode assembly 204. As previously discussed, the energy source 119 DC pulses at frequencies in the range of about 1 Hz to about 1000 Hz, amplitudes in the range of about ±100 to about ±3000 VDC, and pulse widths (e.g., pulse durations) in the range of about 1 μs to about 100 ms to the first and second plate electrodes 204a, b of the electrode assembly 204. The polarity of the energy delivered to the electrodes (e.g., electrode 104 or electrode 136) may be reversed during the electrical ablation therapy. For example, the polarity of the DC pulses initially delivered at amplitudes in the range of about +100 to about +3000 VDC may be reversed to amplitudes of about −100 to about −3000 VDC. Preferably, the tumor 110 may be electrically ablated with DC pulses at frequencies of about 10 Hz to about 100 Hz, amplitudes in the range of about +700 to about +1500 VDC, and pulse widths of about 10 μs to about 50 μs.

[0065] FIGS. 8A-D are side views of one embodiment of an electrical ablation device 300 shown in various stages of deployment. In one embodiment, the electrical ablation device 300 may be used in treatment of abnormal tissues or growths, such as cancers or tumors, formed in or on solid organs, BPH, and restricted gastric tissue using IRE energy. The electrical ablation device 300 may be used to electrically ablate abnormal tissues or growths, such as cancers or tumors, formed in solid organs using IRE energy. In other embodiments, electrical ablation treatment may be applied using other forms of electrical energy, such as those described herein.

[0066] FIG. 8A illustrates one embodiment of the electrical ablation device 300 being deployed through the tumor 110 and the liver 112. In the illustrated embodiment, the electrical ablation device 300 comprises an electrode assembly 302 that is attachable to a solid organ such as the liver 112. In one embodiment, the electrode assembly 302 comprises a sharp distal end 304 suitable for penetrating the liver 112 and the tumor 110. The electrode assembly 302 comprises first and second arm electrodes 302a, 302b configured as first and second electrodes. The first and second arm electrodes 302a, b are initially folded and contained within a hollow body 308 of the electrode assembly 302 to enable the electrode to pierce and penetrate the liver 112 and the tumor 110 with the sharp distal end 304. The first and second arm electrodes 302a, b each comprises at least one electrically conductive portion that is formed of or coated with an electrically conductive material such as medical grade stainless steel, for example, and are coupled to the energy source 119 (previously described with reference to FIGS. 1-5) through one or more electrically conductive wires 220a, b that form the cable 106 as shown in FIG. 7C. The hollow body 308 is formed of an electrically insulative material such as medical grade polyester, for example, to electrically isolate the hollow body 308 from the first and second arm electrodes 302a, b. In one embodiment the first arm electrode 302a may be configured as the anode (+) electrode coupled to the positive terminal of the energy source 119 and the second arm electrode 302b may be configured as the cathode (−) electrode coupled to the negative terminal of the energy source 119. It will be appreciated that the polarity of the first and second arm electrodes 302a, b may be reversed such that the first arm electrode 302a is configured as the cathode (−) electrode and the second arm electrode 302b is configured as the anode (+) electrode by reversing the output polarity of the energy source 119.

[0067] As previously discussed, the cable 106 is attached to the connector 114 through the wall 118 of the stomach 108 using techniques previously described with reference to FIGS. 1-3 and 6, for example. The first and second arm electrodes 302a, b are pivotably movable about respective pivot points 310a, 310b. In various other embodiments, the first and second arm electrodes 302a, b of the electrical ablation device 300 may be coupled to the energy source 119 percutaneously through the abdominal wall 109 (FIG. 19) or wirelessly by replacing the cable 106 with the antenna 904 (FIG. 20). The antenna 904 is coupled to the first arm electrode 302a by a first electrically conductive wire and the antenna 904 is coupled to the second arm electrode 302b by a second electrically conductive wire.

[0068] FIG. 9 is a side view of one embodiment of the electrical ablation device 300. FIG. 10 illustrates a spring-loaded arm portion of the embodiment of the electrical ablation device 300 shown in FIG. 9. As shown in FIGS. 8B, 8C, 9, and 10, the first and second arm electrodes 302a, b are pivotally movable outwardly in the directions shown by arrows A and B through respective longitudinal slots 312a, 312b formed in the hollow body 308 of the electrode assembly 302. In one embodiment, the first and second arm electrodes 302a, b are spring loaded and may be actuated by internal springs or other actuation mechanisms. As shown in FIG. 10 the first arm electrode 302a comprises a spring 316 to open the first arm electrode 302a outwardly in direction A. Although not shown, the second arm electrode 302b also comprises a spring 316 to open the second arm electrode 302b outwardly in direction B.

[0069] Referring to FIGS. 8A-D, the illustrated embodiment of the electrical ablation device 300 is shown in use in treatment of the tumor 110 formed in the liver 112 using electrical energy. As shown in FIG. 8A, the first and second arm electrodes 302a, b are folded and spring loaded inside the hollow body 308 of the electrode assembly 302. The distal end 304 of the electrode assembly 302 is inserted in direction C into one side of the liver 112, through the tumor 110, and out the other side of the liver 112. As shown in FIG. 8B, the distal end 304 of the electrode assembly 302 is pushed in direction C through the other side of the liver 112 until the first arm electrode 302a is exposed in the hollow body lumen 314 surrounding the liver 112 enabling the first arm electrode 302a to spring open in direction A under the force of the spring 316 (FIG. 10). Once the first arm electrode 302a is deployed, the electrode assembly 302 is retracted by pulling in direction D until the second arm electrode 302b is exposed in the hollow body lumen 314 surrounding the liver 112 and enabling the second arm electrode 302b to open in direction B, as shown in FIG. 8C. As shown in FIG. 8D the liver 112 may be slightly compressed such that y₂<y₁, where y₁ is the pre-compressed thickness of the liver 112 and y₂ is the compressed thickness of the liver 112.

[0070] As shown in FIG. 8D, the tumor 110 may be electrically ablated by applying IRE energy to the electrode assembly 302 when the first and second arm electrodes 302a, b are deployed. As previously discussed, the energy source 119 (previously described with reference to FIGS. 1-5) supplies DC pulses at frequencies in the range of about 1 Hz to about 1000 Hz, amplitudes in the range of about ±100 to about ±3000 VDC, and pulse widths (e.g., pulse durations) in the range of about 1 μs to about 100 ms to the electrode assembly 302. The polarity of the energy delivered to the first and second arm electrodes 302a, b electrodes may be reversed during the electrical ablation therapy. For example, the polarity of the DC pulses initially delivered at amplitudes in the range of about +100 to about +3000 VDC may be reversed to amplitudes of about −100 to about −3000 VDC. Preferably, the tumor 110 may be electrically ablated with DC pulses at frequencies of about 10 Hz to about 100 Hz, amplitudes in the range of about +700 to about +1500 VDC, and pulse widths of about 10 μs to about 50 μs.

[0071] FIGS. 11A-C are side views of one embodiment of an electrical ablation device 400 shown in various stages of deployment. In one embodiment, the electrical ablation device 400 may be used in treatment of abnormal tissues or growths, such as cancers or tumors, formed in or on solid organs, BPH, and restricted gastric tissue using IRE energy. In other embodiments, electrical ablation treatment may be applied using other forms of electrical energy, such as those described herein. FIG. 11A illustrates one embodiment of the electrical ablation device 400 being deployed through the tumor 110 and the liver 112. In the illustrated embodiment, the electrical ablation device 400 comprises an electrode assembly 402 that is attachable to a solid organ such as the liver 112. In one embodiment, the electrode assembly 402 comprises a sharp distal end 404 adapted to pierce and penetrate the liver 112 and the tumor 110. The sharp distal end 404 can be inserted into one side of the liver 112, through the tumor 110, and out the opposite side of the liver 112. In one embodiment, the electrode assembly 402 comprises a first canopy electrode 402a and a second canopy electrode 402b. The first and second canopy electrodes 402a, b each comprises at least one electrically conductive portion that is formed of or coated with an electrically conductive material such as medical grade stainless steel, for example, and are coupled to the energy source 119 (previously described with reference to FIGS. 1-5) through one or more electrically conductive wires 220a, b that form the cable 106 as shown in FIG. 7C. The first and second canopy electrodes 402a, b are electrically coupled to an electrically conductive wire disposed within the cable 106 to couple the first and second canopy electrodes 402a, b to the energy source 119 previously described with reference to FIGS. 1-5. In one embodiment the first canopy electrode 402a may be configured as the anode (+) electrode coupled to the positive terminal of the energy source 119 and the second canopy electrode 402b may be configured as the cathode (−) electrode coupled to the negative terminal of the energy source 119. It will be appreciated that the polarity of the first and second canopy electrodes 402a, b may be reversed such that the first canopy electrode 402a is configured as the cathode (−) electrode and the second canopy electrode 402b is configured as the anode (+) electrode by reversing the output polarity of the energy source 119. In various other embodiments, the first and second canopy electrodes 404a, b of the electrical ablation device 400 may be coupled to the energy source 119 percutaneously through the abdominal wall 109 (FIG. 19) or wirelessly by replacing the cable 106 with the antenna 904 (FIG. 20). The antenna 904 is coupled to the first canopy electrode 404a by a first electrically conductive wire and the antenna 904 is coupled to the second canopy electrode 404b by a second electrically conductive wire.

[0072] The first and second canopy electrodes 402a, b have an umbrella-like structure such that each canopy electrode 402a, b can be independently opened and closed. In FIG. 11A, the first and second canopy electrodes 402a, b are shown in a closed position used for insertion through the tumor 110 and the liver 112. The first and second canopy electrodes 402a, b each comprise a plurality of ribs 406a, b, shown in cross-section, to support electrically conductive sheets 414a, b. The electrically conductive sheets 414a, b are attached to the respective plurality of ribs 406a, b. Each of the first and second canopy electrodes 402a, b comprises a plurality of stretchers 408a, b that are pivotally coupled to the ribs 406a, b on one end and pivotally coupled to movable runners 410a, b on the other end. The first and second canopy electrodes 402a, b may be opened and closed by slidably moving the runners 410a, b along shafts 412a, b. When the first and second canopy electrodes 402a, b are opened, the electrically conductive sheets 414a, b are stretched out in a substantially circular structure. FIG. 11D is a top-view of one embodiment of the first canopy electrode 402a of the electrical ablation device 400 shown in an open position. The second canopy electrode 402b assumes a similar structure when opened.

[0073] In the embodiment shown in FIG. 11A, the first and second canopy electrodes 402a, b are shown in a closed position. The first electrode canopy electrode 402a may be opened by slidably moving the runner 410a in direction C. The second canopy electrode 402b may be opened by slidably moving the runner 410b in direction D. A first shaft 416a is coupled to the first canopy electrode 402a and is slidably received within a second hollow shaft 416b. This allows the first and second canopy electrodes 402a, b to be pulled towards each other after they are opened to compress the liver 112. The first and second shafts 416a, b are formed of an electrically insulative material such as medical grade polyester, for example, to electrically isolate the first and second shafts 416a, b from the first and second canopy electrodes 402a, b.

[0074] Referring to FIGS. 11A-C, the illustrated embodiment of the electrical ablation device 400 is shown in use in treatment of the tumor 110 formed in the liver 112 using IRE energy. As shown in FIG. 11A, the first and second canopy electrodes 402a, b are folded in a closed position. The distal end 404 of the second canopy electrode 402a is inserted in direction C into one side of the liver 112, through the tumor 110, and out the other side of the liver 112. As shown in FIG. 11B, both the first and second canopy electrodes 402a, b are opened by slidably moving the respective runners 410a, b in the respective directions C and D as discussed above. When the first and second canopy electrodes 402a, b are opened, the stretchers 408a, b stretch out the electrically conductive sheets 414a, b. Then, the first canopy electrode 402a is pulled in direction D and the second canopy electrode 402b is pushed in direction C such that the first shaft 416a is slidably received within the second shaft 416b and the first and second canopy electrodes 402a, b are pulled adjacent to the outer surfaces of the liver 112, as shown in FIG. 11C. The first and second canopy electrodes 402a, b may be pulled towards each other to compress the portion of the liver 112 located therebetween. As shown in FIG. 11C the liver 112 may be slightly compressed such that y₂<y₁, where y₁ is the pre-compressed thickness of the liver 112 and y₂ is the compressed thickness of the liver 112.

[0075] With reference to FIG. 11C, the tumor 110 may be electrically ablated by applying IRE energy to the electrode assembly 402 when the first and second electrodes 402a, b are deployed. As previously discussed, the energy source 119 (previously described with reference to FIGS. 1-5) supplies DC pulses at frequencies in the range of about 1 Hz to about 1000 Hz, amplitudes in the range of about ±100 to about ±3000 VDC, and pulse widths (e.g., pulse durations) in the range of about 1 μs to about 100 ms to the first and second canopy electrodes 402a, b. The polarity of the energy delivered to the first and second canopy electrodes 402a, b may be reversed during the electrical ablation therapy. For example, the polarity of the DC pulses initially delivered at amplitudes in the range of about +100 to about +3000 VDC may be reversed to amplitudes of about −100 to about −3000 VDC. Preferably, the tumor 110 may be electrically ablated with DC pulses at frequencies of about 10 Hz to about 100 Hz, amplitudes in the range of about +700 to about +1500 VDC, and pulse widths of about 10 μs to about 50 μs.

[0076] FIG. 12 illustrates one embodiment of an electrical ablation device 500 attached to a solid organ prior to being connected to the energy source 119 (previously described with reference to FIGS. 1-5). In one embodiment, the electrical ablation device 500 may be used in treatment of abnormal tissues or growths, such as cancers or tumors, formed in or on solid organs, BPH, and restricted gastric tissue using IRE energy. In other embodiments, electrical ablation treatment may be applied using other forms of electrical energy, such as those described herein. In the embodiment illustrated in FIG. 12, the electrical ablation device 500 comprises an electrode 504. The electrode 504 is configured for attachment to a solid organ, such as the liver 112. In the embodiment illustrated in FIG. 12, the electrode 504 is attached to the liver 112. The electrode 504 may be attached to the liver 112, or any solid organ, using a variety of fasteners. The electrode 504 comprises a first plate electrode 504a and a second plate electrode 504b and a center post 504c located therebetween. The first and second plate electrodes 504a, b each comprises at least one electrically conductive portion that is formed of or coated with an electrically conductive material such as medical grade stainless steel, for example, and are electrically coupled to respective first and second conductor portions of the cable 506 to deliver electrical ablation energy to the tumor 110 from the energy source 119. The center post 504c is inserted through the tumor 110 and the first and second plate electrodes 504a, b are positioned on either side of the tumor 110 on an outer surface of the liver 112. The center post 504c is formed of an electrically insulative material such as medical grade polyester, for example, to electrically isolate the center post 504c from the first and second plate electrodes 504a, b. In one embodiment the first plate electrode 504a may be configured as the anode (+) electrode coupled to the positive terminal of the energy source 119 and the second plate electrode 504b may be configured as the cathode (−) electrode coupled to the negative terminal of the energy source 119. It will be appreciated that the polarity of the first and second plate electrodes 504a, b may be reversed such that the first plate electrode 504a is configured as the cathode (−) electrode and the second plate electrode 504b is configured as the anode (+) electrode by reversing the output polarity of the energy source 119. In various other embodiments, the first and second plate electrodes 504a, b of the electrical ablation device 500 may be coupled to the energy source 119 percutaneously through the abdominal wall 109 (FIG. 19) or wirelessly by replacing the cable 106 with the antenna 904 (FIG. 20). The antenna 904 is coupled to the first plate electrode 504a by a first electrically conductive wire and the antenna 904 is coupled to the second plate electrode 504b by a second electrically conductive wire.

[0077] In the illustrated embodiment, the first plate electrode 504a is located above the tumor 110 and the second plate electrode 504b is located below the tumor 110. The first and second plate electrodes 504a, b are configured as electrodes. The first plate electrode 504a comprises a connector 114 to couple the electrode 504 to an energy source via an endoscopically, laparoscopically, transcutaneously, or percutaneously insertable cable 506 comprising the mating plug 115 to electrically couple to the connector 114. The first and second plate electrodes 504a, b are electrically coupled to respective first and second conductor portions of the cable 506, for example. In one embodiment, the first and second plate electrodes 504a, b may be introduced endoscopically, laparoscopically, or via open surgical procedures such as a laparotomy. As previously discussed, the cable 506 also may be introduced into the stomach 108 trans-orally through the access or working channel of the endoscope. In the illustrated embodiment, the cable 506 is inserted percutaneously through the abdominal wall 109.

[0078] With reference to FIG. 12, the tumor 110 may be electrically ablated by applying IRE energy to the electrode 504 when the first and second plate electrodes 504a, b are deployed. As previously discussed, the energy source 119 (previously described with reference to FIGS. 1-5) supplies DC pulses at frequencies in the range of about 1 Hz to about 1000 Hz, amplitudes in the range of about ±100 to about ±3000 VDC, and pulse widths (e.g., pulse durations) in the range of about 1 μs to about 100 ms to the first and second plate electrodes 504a, b of the electrode 504. The polarity of the energy delivered to the first and second plate electrodes 504a, b of the electrode 504 may be reversed during the electrical ablation therapy. For example, the polarity of the DC pulses initially delivered at amplitudes in the range of about +100 to about +3000 VDC may be reversed to amplitudes of about −100 to about −3000 VDC. Preferably, the tumor 110 may be electrically ablated with DC pulses at frequencies of about 10 Hz to about 100 Hz, amplitudes in the range of about +700 to about +1500 VDC, and pulse widths of about 10 μs to about 50 μs. The tumor 110 may be monitored over time (weeks) to observe shrinkage. The treatment may be repeated until the tumor 110 disappears.

[0079] FIG. 13 illustrates one embodiment of an electrical ablation device 600. In the illustrated embodiment, the electrical ablation device 600 comprises a balloon electrode 602 that can be inserted into the uterine cavity 638 (FIGS. 14A-B, 15A) for the treatment of menorrhagia using IRE energy. In other embodiments, electrical ablation treatment may be applied using other forms of electrical energy, such as those described herein. In other embodiments, the electrode may be implemented as a sponge or similar structure. In FIG. 13, there is shown a lateral cross-sectional view of the electrical ablation device 600. In one embodiment, the electrical ablation device 600 is primarily intended for non-surgical entry into the uterine cavity 638 of a female although one of ordinary skill in the art will recognize its usefulness in other related procedures. The electrical ablation device 600 has an elongate tubular body 610 extending from a distal end 612 to a proximal end 614. Located on the marginal distal end 612 of the body 610 is an inflatable intracervical/intrauterine balloon electrode 602. As shown in FIG. 13, the balloon electrode 602 is in a deflated state. A connector 628 for coupling the energy source 119 to the electrical ablation device 600 is located at a proximal end 620 of a conduit 604, which will be described in greater detail below.

[0080] In one embodiment, the electrical ablation device 600 also comprises an inflation fluid line 616 having a distal 622, which terminates within the body 610, and a proximal end 620. The inflation fluid line 616 enters the body 610 at a fluid line coupler 630. The proximal end 620 of the inflation fluid line 616 may be coupled to a conventional inline rotary valve (not shown) to control the flow of inflation fluid. A proximal end of the inline rotary valve is removably coupled to a conventional inflation syringe 626 (FIGS. 15A-B). A cylindrical collar member 632 is slidably mounted on the tubular body 610 between the balloon electrode 602 and the fluid line coupler 630. The collar member 632 comprises an outwardly extending circumferential flange 634 at its distal end.

[0081] As shown, the inner conduit 604 defines a working lumen 606 is disposed within the body 610 and extends the entire length of the body 610 from the distal end 612 to the proximal end 614. The working lumen 606 of the inner conduit 604 provides an electrical communication path for the introduction of one or more electrically conductive wires 608 for delivering electrical energy from the energy source 119 to the balloon electrode 602. The one ore more conductors 608 may be electrically coupled to the balloon electrode 602 to convey electrical energy from the energy source 119 thereto.

[0082] The inflation fluid line 616 defines an inflation lumen 618. The inflation lumen 618 starts at the proximal end 620 of the inflation fluid line 616 and extends therethrough to the distal end 622 thereof. The inflation lumen 618 fluidically communicates with the interior of the balloon electrode 602 via an aperture 624. The inflation lumen 618 of the inflation fluid line 616 provides a fluid communication path for inflating the balloon electrode 602 with a fluid 629 (FIG. 15A). The fluid 629 may be either saline or air or other suitable electrically conductive inflation fluid. An inline rotary valve (not shown) may operate to maintain the balloon electrode 602 in the inflated state after inflation by the inflation syringe 626 (FIGS. 15A, 15B). A port 639 may be defined at the distal end of the working lumen 406 to provide a fluid communication path between the working lumen 406 and the external portion of the balloon electrode 602 to deliver fluids into the hollow body lumen (e.g., the uterine cavity 638) outside of the balloon electrode 602.

[0083] FIGS. 14A and 14B show the progression of one embodiment of the electrical ablation device 600 penetrating through the cervix 636 and insertion into the uterine cavity 638. FIG. 14A illustrates the balloon electrode 602 in a deflated state inserted into the cervix 636. FIG. 14B illustrates the balloon electrode 602 inserted in the uterine cavity 638 in a partially inflated state. Once the balloon electrode 602 is inserted into the uterine cavity 638, the balloon electrode 602 may be fully inflated.

[0084] In FIG. 15A, the electrical ablation device 600 is shown in use entering the cervix 636 with the balloon electrode 602 in a deflated state. Once inserted through the cervix 636 and into the uterine cavity 638, as shown in FIG. 15B, the balloon electrode 602 is inflated by pushing the plunger 640 into the body 642 of the inflation syringe 626. The balloon electrode 602 is inflated with the fluid 629. Once the balloon electrode 602 is inflated, an inline rotary valve (not shown) may be rotated into a “closed position” to prevent communication between the inflation syringe 626 and the inflation lumen 618 (FIG. 13). When it is desirable to deflate the balloon electrode 602, the inline rotary valve may be rotated into an “open position” to reestablish communication between the inflation syringe 626 and the inflation lumen 618. To deflate the balloon electrode 602, the plunger 640 is pulled toward the proximal end of the body 642 of the inflation syringe 626. A conductive fluid may be injected around the balloon electrode 602 to expand the zone of treatment. The conductive fluid may be delivered through the port 639 (FIG. 13) into the uterine cavity 638 to expand the zone of treatment.

[0085] The various components of the electrical ablation device 600 are made from conventional materials such as nylon, polyethylene, or a composite. In one embodiment, the intracervical/intrauterine balloon electrode 602 is made from or comprises an electrically conductive material to transmit electrical energy from the energy source 119 to the internal walls 644 of the uterine cavity 638 for applying electrical ablation therapy thereto. In another embodiment, the intracervical/intrauterine balloon electrode 602 may be made from a medical grade polyurethane material comprising an electrically conductive coating on an outer surface thereof. In another embodiment, the balloon electrode 602 may be made from an electrically conductive material. In yet another embodiment, the balloon electrode 602 may be made from an electrically insulative material, such as the medical grade polyurethane, and inflated with a conductive fluid (e.g., saline) to form the electrically conductive portion of the balloon electrode 602. In one embodiment the balloon electrode 602 may be configured as the anode (+) electrode coupled to the positive terminal of the energy source 119 and in another embodiment the balloon electrode 602 may be configured as the cathode (−) electrode coupled to the negative terminal of the energy source 119. It will be appreciated that the polarity of the balloon electrode 602 may be reversed by reversing the output polarity of the energy source 119. In one embodiment, the balloon electrode 602 may be configured as either the anode (+) or the cathode (−) relative to a reference polarity. For example, the balloon electrode 602 may be configured as the cathode (+) coupled to the positive output of the energy source 119 relative to a ground plane cathode (−) located beneath the patient and coupled to the negative terminal of the energy source 119.

[0086] In the embodiment illustrated in FIGS. 14A-B and 15A-B, the electrical ablation device 600 is configured for use as an intrauterine device for treating menorrhagia through the use of electrical energy. In one embodiment, the balloon electrode 602 applies IRE energy supplied by the energy source 119. As previously described, IRE provides an effective method for destroying cells while avoiding some of the negative complications of heat-inducing therapies. Namely, IRE destroys cells without the use of heat and does not destroy cellular support structure or regional vasculature. In the illustrated embodiment, the balloon electrode 602 can be inserted into the uterine cavity 638 and once placed therein the balloon electrode 602 can be expanded or inflated with the fluid 629 to make substantially complete contact with the uterine wall 644.

[0087] After the balloon electrode 602 is inflated, electrical ablation energy is supplied by the energy source 119 to electrically ablate the internal walls 644 of the uterine cavity 638 to treat menorrhagia by applying IRE energy to the balloon electrode 602. As previously discussed, the energy source 119 (previously described with reference to FIGS. 1-5) supplies DC pulses at frequencies in the range of about 1 Hz to about 1000 Hz, amplitudes in the range of about ±100 to about ±3000 VDC, and pulse widths (e.g., pulse durations) in the range of about 1 μs to about 100 ms to the balloon electrode 602. The polarity of the energy delivered to the balloon electrode 602 may be reversed during the electrical ablation therapy. For example, the polarity of the DC pulses initially delivered at amplitudes in the range of about +100 to about +3000 VDC may be reversed to amplitudes of about −100 to about −3000 VDC. Preferably, the internal walls 644 of the uterine cavity 638 may be electrically ablated with DC pulses at frequencies of about 10 Hz to about 100 Hz, amplitudes in the range of about +700 to about +1500 VDC, and pulse widths of about 10 μs to about 50 μs. Multiple placements of the balloon electrode 602 can be performed to treat large areas of the uterus. A conductive fluid may be injected around the balloon electrode 602 to expand the zone of treatment for a given irreversible electroporation treatment. The menorrhagia may be monitored over time (weeks) to observe the effectiveness of the electrical ablation therapy. The treatment may be repeated until the menorrhagia disappears.

[0088] FIG. 16 illustrates one embodiment of an electrical ablation device 700 for removing excess skin 702 using IRE energy. In other embodiments, electrical ablation treatment may be applied using other forms of electrical energy, such as those described herein. The electrical ablation device 700 may be used in minimally invasive therapy for removal of the excess skin 702 following excess weight loss due to bariatric surgery. This therapy involves the administration of IRE energy pulses to excess skin 702 at various sites on a patient's body. As previously described with reference to FIGS. 1-5, the IRE energy pulses may be supplied by the energy source 119. In the embodiment illustrated in FIG. 16, the electrical ablation device 700 comprises needle electrodes 704a, 704b that may be inserted through the skin 702. The needle electrodes 704a, b each comprises at least one electrically conductive portion that is formed of or coated with an electrically conductive material such as medical grade stainless steel, for example. In one embodiment the first needle electrode 704a may be configured as the anode (+) electrode coupled to the positive terminal of the energy source 119 and the second needle electrode 704b may be configured as the cathode (−) electrode coupled to the negative terminal of the energy source 119. It will be appreciated that the polarity of the first and second needle electrodes 704a, b may be reversed such that the first needle electrode 704a is configured as the cathode (−) electrode and the second needle electrode 704b is configured as the anode (+) electrode by reversing the output polarity of the energy source 119. It will be appreciated that a plurality of needle electrodes may be employed. Once the needle electrodes 704a, b are inserted at the appropriate level below the outer epidermis layer of the skin 702, IRE energy pulses may be administered to the needle electrodes 704a, b by the energy source 119 to destroy the cells of the epidermis, dermis, and subcutis layers of the skin 702. The needle electrodes 704a, b may be moved to various locations on the excess skin 702 flap, and the treatment repeated.

[0089] The therapeutic treatments administered using the embodiments of the electrical ablation device 700 illustrated in FIG. 16 result in a reduction in the surface area of the skin 702. The therapy may be administered over several weeks or months, with each therapy resulting in the gradual removal of the excess skin 702. The electrical ablation energy is supplied by the energy source 119. As previously discussed, the energy source 119 (previously described with reference to FIGS. 1-5) supplies DC pulses at frequencies in the range of about 1 Hz to about 1000 Hz, amplitudes in the range of about ±100 to about ±3000 VDC, and pulse widths (e.g., pulse durations) in the range of about 1 μs to about 100 ms to the needle electrodes 704a, b. The polarity of the energy delivered to the needle electrodes 704a, b may be reversed during the electrical ablation therapy. For example, the polarity of the DC pulses initially delivered at amplitudes in the range of about +100 to about +3000 VDC may be reversed to amplitudes of about −100 to about −3000 VDC. Preferably, the excess skin 702 may be electrically ablated with DC pulses at frequencies of about 10 Hz to about 100 Hz, amplitudes in the range of about +700 to about +1500 VDC, and pulse widths of about 10 μs to about 50 μs. Multiple placements of the needle electrodes 704a, b can be performed to treat large areas of the excess skin 702.

[0090] FIG. 17 illustrates one embodiment of an electrical ablation device 800 for removing excess skin 702. In one embodiment, the excess skin 702 may be removed using IRE energy. In other embodiments, electrical ablation treatment may be applied using other forms of electrical energy, such as those described herein. The electrical ablation device 800 may be used in minimally invasive therapy for removal of the excess skin 702 that normally follows excess weight loss due to bariatric surgery. In the embodiment illustrated in FIG. 17, first and second electrodes 802a, 802b are configured as rollers (first and second roller electrodes 802a, b). The first and second electrodes 802a, b have a substantially circular or disk-like body defining a hub 812 and are arranged to rotate about an axis. The IRE energy pulses from the energy source 119 (previously described with reference to FIGS. 1-5) are administered as the first and second roller electrodes 802a, b move over the patient's skin 702. The IRE energy destroys the cells in the epidermis and the dermis layers of the skin 702. In one embodiment the first roller electrode 802a may be configured as the anode (+) electrode coupled to the positive terminal of the energy source 119 and the second roller electrode 802b may be configured as the cathode (−) electrode coupled to the negative terminal of the energy source 119. It will be appreciated that the polarity of the first and second roller electrodes 802a, b may be reversed such that the first roller electrode 802a is configured as the cathode (−) electrode and the second roller electrode 802b is configured as the anode (+) electrode by reversing the output polarity of the energy source 119. In one embodiment, both the first and second roller electrodes 802a, b may be coupled to the same polarity and may be configured as the anode (+) or the cathode (−) relative to a reference polarity. For example, the first and second roller electrodes 802a, b may be configured as the cathode (+) coupled to the positive output of the energy source 119 relative to a ground plane cathode (−) located beneath the patient and coupled to the negative terminal of the energy source 119.

[0091] FIG. 18 is a detail cross-sectional view of one embodiment of the electrode 802a. Those skilled in the art will appreciate that the roller electrode 802b may be constructed in a similar fashion. As shown in FIG. 18, the roller electrode 802a comprises a body having at least one electrically conductive portion at an outer surface thereof that is formed of or coated with an electrically conductive material (e.g., copper, aluminum, brass, steel, medical grade stainless steel). The roller electrode 802a rotates about a cylindrical bearing 804 positioned within the hub 812. The cylindrical bearing 804 is formed of an electrically conductive material and is in electrical communication with the electrically conductive portion of the roller electrode 802a body. An electrically insulative sleeve 806 formed of medical grade polyester, for example, is positioned between the cylindrical bearing 804 and a shaft 808. The shaft 808 is received within the hub 812 and defines as an axis of rotation for the roller electrode 802a. An electrically conductive wire 810 is electrically coupled to the bearing 804 and thus to the roller electrode 802a. Electrical energy from the energy source 119 is conducted via the conductor 810 to the roller electrode 802a. The embodiments of the roller electrodes 802a, b are not limited in this context.

[0092] The therapeutic treatments administered using the embodiments of the electrical ablation device 800 illustrated in FIGS. 17 and 18 result in a reduction in the surface area of the skin 702. The therapy may be administered over several weeks or months, with each therapy resulting in the gradual removal of the excess skin 702. The electrical ablation energy is supplied by the energy source 119. As previously discussed, the energy source 119 (previously described with reference to FIGS. 1-5) supplies DC pulses at frequencies in the range of about 1 Hz to about 1000 Hz, amplitudes in the range of about ±100 to about ±3000 VDC, and pulse widths (e.g., pulse durations) in the range of about 1 μs to about 100 ms to the roller electrodes 802a, b. The polarity of the energy delivered to the roller electrodes 802a, b may be reversed during the electrical ablation therapy. For example, the polarity of the DC pulses initially delivered at amplitudes in the range of about +100 to about +3000 VDC may be reversed to amplitudes of about −100 to about −3000 VDC. Preferably, the excess skin 702 may be electrically ablated with DC pulses at frequencies of about 10 Hz to about 100 Hz, amplitudes in the range of about +700 to about +1500 VDC, and pulse widths of about 10 μs to about 50 μs. Multiple placements of the roller electrodes 802a, b can be performed to treat large areas of the excess skin 702.

[0093] FIG. 20 illustrates one embodiment of a wireless electrical ablation device 900 shown in use. The electrical ablation device 900 comprises one or more electrodes 902 connected to an antenna 904. In various embodiments, the one or more electrodes 902 may be configured as any one of the previously discussed electrodes 100, 200, 300, 400, 500, 600. In one embodiment, the energy source 119 may comprise a wireless transmitter 906 configured to deliver energy 910 to the one or more electrodes 902 via an antenna 908. The energy source 119 transmits the energy 910 through the transmitting antenna 908, which is received by the antenna 904, thus eliminating the need to perforate the hollow body lumen or the patient's skin. The embodiments are not limited in this context.

[0094] The various embodiments of the electrical ablation devices and techniques described herein may be employed in electrical ablation therapy of tissue. Embodiments of the electrical ablation devices and techniques described herein may be employed in treatment or removal of diseased tissue, restricted gastric tissue, adipose tissue, abnormal tissue masses, tumors, lesions, adhesions, BPH, and menorrhagia, among others, located inside the patient's body using electrical ablation energy. Other embodiments of the electrical ablation devices described herein may be employed in treatment or removal of excess skin following bariatric surgery using electrical ablation energy.

[0095] The embodiments of the electrical ablation 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 electrical ablation devices inside the patient using a combination of minimally invasive and open surgical techniques. Minimally invasive techniques provide more accurate and effective access to the treatment region for diagnostic and treatment procedures. To reach internal treatment regions within the patient, the electrical ablation devices described herein may be inserted through natural openings of the body such as the mouth, 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 Natural Orifice Translumenal Endoscopic Surgery (NOTES™) procedures. Surgical devices, such as an electrical ablation devices, may be introduced to the treatment region through the working channels of the endoscope to perform key surgical activities (KSA), including, for example, electrical ablation of tissues using IRE energy. Some portions of the electrical therapy ablation devices may be introduced to the tissue treatment region percutaneously or through small—keyhole—incisions.

[0096] 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, anus, and/or vagina). A rigid endoscope may be introduced via trocar through a relatively small—keyhole—incision incisions (usually 0.5-1.5 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.

[0097] Once an electrical ablation device is inserted in the human body internal organs may be reached using trans-organ or translumenal surgical procedures. The electrical ablation device may be advanced to the treatment site using endoscopic translumenal access techniques to perforate a lumen, and then, advance the electrical ablation device and the endoscope into the peritoneal cavity. Translumenal access procedures for perforating a lumen wall, inserting, and advancing an endoscope therethrough, and pneumoperitoneum devices for insufflating the peritoneal cavity and closing or suturing the perforated lumen wall are well known. During a translumenal access procedure, a puncture must be formed in the stomach wall or in the gastrointestinal tract to access the peritoneal cavity. One device often used to form such a puncture is a needle knife which is inserted through the working channel of the endoscope, and which utilizes energy to penetrate through the tissue. A guidewire is then feed through the endoscope and is passed through the puncture in the stomach wall and into the peritoneal cavity. The needle knife is removed, leaving the guidewire as a placeholder. A balloon catheter is then passed over the guidewire and through the working channel of the endoscope to position the balloon within the opening in the stomach wall. The balloon can then be inflated to increase the size of the opening, thereby enabling the endoscope to push against the rear of the balloon and to be feed through the opening and into the peritoneal cavity. Once the endoscope is positioned within the peritoneal cavity, numerous procedures can be performed through the working channel of the endoscope.

[0098] The endoscope may be connected to a video camera (single chip or three chip) and may be attached to a fiber-optic cable system connected to a “cold” light source (halogen or xenon), to illuminate the operative field. The video camera provides a direct line-of-sight view of the treatment region. The abdomen is usually insufflated with carbon dioxide (CO₂) gas to create a working and viewing space. The abdomen is essentially blown up like a balloon (insufflated), elevating the abdominal wall above the internal organs like a dome. CO₂ gas is used because it is common to the human body and can be removed by the respiratory system if it is absorbed through tissue.

[0099] Once the electrical ablation devices are located at the target site, the diseased tissue may be electrically ablated or destroyed using the various embodiments of electrodes discussed herein. The placement and location of the electrodes can be important for effective and efficient electrical ablation therapy. For example, the electrodes may be positioned proximal to a treatment region (e.g., target site or worksite) either endoscopically or transcutaneously (percutaneously). In some implementations, it may be necessary to introduce the electrodes inside the patient using a combination of endoscopic, transcutaneous, and/or open techniques. The electrodes may be introduced to the tissue treatment region through a working channel of the endoscope, an overtube, or a trocar and, in some implementations, may be introduced through percutaneously or through small—keyhole—incisions.

[0100] 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.

[0101] It is preferred that the device is sterilized. This can be done by any number of ways known to those skilled in the art including beta or gamma radiation, ethylene oxide, steam.

[0102] 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.

[0103] Any patent, publication, or other disclosure material, in whole or in part, 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, 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.