Medical device

Abstract

To provide a medical system, a device, and a procedure for treating a tissue by transmitting electric energy to the tissue.SOLUTION: A medical device includes: a shaft including a distal end including a passive electrode defining a center opening extending so as to penetrate the passive electrode; and an active electrode in the inside of the center opening. The active electrode is movable between an extension position where at least the active electrode does not contact the passive electrode and a retraction position where the active electrode contacts the passive electrode.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates to medical systems, devices and methods. More particularly, the present invention relates to medical systems, devices and procedures for treating tissue by delivering electrical energy to the tissue. [Background technology]

[0002] Medical devices such as endoscopes, or other suitable insertion devices, are used in various types of diagnostic and surgical procedures, such as endoscopy, laparoscopy, arthroscopy, gynecological examinations, thoracoscopy, cystoscopy, and the like. Many of these procedures involve the delivery of energy to organ or glandular tissue to treat tumors, infections, and the like. Examples of such procedures include endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESR), endoscopic submucosal dissection (ESD), polypectomy, mucosal resection, and the like. In particular, such procedures are performed by inserting an insertion device into a patient's body through a surgical incision or natural anatomical orifice (e.g., mouth, vagina, or rectum) and performing a surgery or operation at a target site with an auxiliary device inserted through the insertion device.

[0003] During a medical procedure, a user may use an injection needle inserted through an insertion device to form (or re-form) a bleb in or under the tissue to be removed. To deliver energy to the tissue, the user may be required to remove the injection needle from the insertion device and deliver an energy delivery device through the insertion device to the target tissue. Additionally, during the procedure, the user may perform hemostasis on the target tissue or surrounding tissue. This device replacement may increase the time and risk of the medical procedure, and the energy delivery device may not be able to deliver adequate energy in both the incision and hemostasis modes.

[0004] The apparatus and methods of the present invention may rectify some of the above problems or solve other problems of the prior art. Summary of the Invention

[0005] Examples of the present invention relate to medical devices for treating tissue by delivering electrical energy to the tissue, and related methods of use thereof. Each example disclosed herein includes one or more of the elements described in connection with any of the other disclosed examples.

[0006] In one example, a medical device includes a shaft including a distal end including a passive electrode forming a central opening extending through the passive electrode, and an active electrode within the central opening, the active electrode being movable between at least an extended position in which the active electrode does not contact the passive electrode, and a retracted position in which the active electrode contacts the passive electrode.

[0007] The medical device includes one or more of the following elements: when the active electrode is energized in the extended position, the passive electrode is insulated and when the active electrode is energized in the retracted position, the passive electrode is energized. The passive electrode includes a generally cylindrical shape having a flat distal end face and at least one rounded distal end. The medical device further includes an outer insulating member surrounding at least a portion of the passive electrode. The medical device further includes an inner insulating member within a central opening between the active and passive electrodes.

[0008] The medical device further includes a handle having a body and a movable part, at least one of the body and the movable part including a slot, and in response to sliding the movable part in a first direction relative to the body, the passive electrode extends, and in response to sliding the movable part in a second direction relative to the body, the passive electrode retracts. At least one of the body and the movable part includes a fluid port for connecting a fluid source to the handle, and at least one of the body and the movable part includes a hub for connecting an energy source to the handle. The medical device further includes a drive element, the drive element extending from the handle to the active electrode, electrically connecting the energy source to the active electrode and capable of moving the active electrode in a distal or proximal direction based on relative movement between the body and the movable part.

[0009] The entire distal-most surface of the passive electrode is conductive. The active electrode includes a distal tip and a longitudinal shaft. In the retracted position, only the proximal surface of the distal tip of the active electrode contacts the passive electrode. The distal tip includes a width, measured transversely to the longitudinal axis of the medical device, that is greater than a width of the longitudinal shaft. The distal tip includes a width, measured transversely to the longitudinal axis of the medical device, that is greater than a diameter of the central opening. The shaft includes a central lumen configured to direct a fluid flow therethrough, and the active electrode includes an electrode lumen in fluid communication with the central lumen. The electrode lumen is configured to receive a fluid flow from the central lumen and direct the fluid distally through the opening. The distal end includes a cap having a reduced diameter stop surface radially surrounding a portion of the active electrode, and the active electrode includes an enlarged diameter portion proximal to the distal tip of the active electrode. The stop surface of the cap and the enlarged diameter portion of the active electrode may limit distal extension of the active electrode.The medical device further includes an insulating member radially inward of the reduced diameter stop surface of the cap.

[0010] In another aspect, a medical device includes a shaft including a distal end cap including a conductive portion, a movable electrode disposed within and movable relative to the distal end cap, the movable electrode configured to receive energy from an energy source, and a control element configured to control a position of the movable electrode between at least a retracted position and an extended position, wherein in the retracted position, the movable electrode is in electrical contact with the conductive portion and in the extended position, the movable electrode is electrically isolated from the conductive portion.

[0011] The medical device may include one or more of the following elements: The medical device further includes a fluid source connected to the shaft. The shaft includes a shaft lumen in fluid communication with the fluid source, and the movable electrode includes an electrode lumen in fluid communication with the shaft lumen. The medical device further includes an energy source. The energy source may be an RF generator. The movable electrode is moved through a central opening in the distal end cap such that the conductive portion radially surrounds the movable electrode.

[0012] In a further aspect, a method of treating tissue includes inserting a distal portion of a medical device into a body cavity, the medical device including a movable electrode and a conductive portion on the distal portion, extending the movable electrode distally such that the movable electrode is electrically insulated from the conductive portion, energizing the movable electrode, applying the movable electrode to a target site within the body cavity to deliver electrical energy to the target site, retracting the movable electrode proximally such that the movable electrode is electrically connected to the conductive portion, and applying the movable electrode and the conductive portion to the target site or another portion of the body cavity to deliver electrical energy.

[0013] The method may include one or more of the following elements: The medical device further includes a fluid lumen and the movable electrode includes a fluid outlet. The method further includes simultaneously delivering the fluid and applying electrical energy to the movable electrode.

[0014] Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention. [Brief description of the drawings]

[0015] [Figure 1A] 1 illustrates an exemplary medical device in accordance with an aspect of the present invention. [Figure 1B] 1 illustrates an exemplary medical device in accordance with an aspect of the present invention. [Figure 2A] 1A and 1B in an extended and retracted configuration, according to an embodiment of the present invention. [Figure 2B] 1A and 1B in an extended and retracted configuration, according to an embodiment of the present invention. [Figure 3A] 1A and 1B in an extended and retracted configuration, according to an embodiment of the present invention. [Figure 3B]1A and 1B in an extended and retracted configuration, according to an embodiment of the present invention. [Figure 3C] 1A and 1B in extended and retracted configurations, according to an embodiment of the present invention. [Figure 4] 1 is a flow diagram illustrating an exemplary method for treating tissue, in accordance with an aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Examples of the invention include devices and methods for enhancing and improving the effectiveness, efficiency and / or safety of treating tissue, for example, when applying electrical energy to tissue and, in certain embodiments, when delivering fluids into and under tissue during medical procedures. For example, aspects of the invention allow a user (e.g., a physician, medical technician, or other medical service provider) to apply electrical energy or heat to tissue using a medical device having electrodes and to deliver fluids into and / or under tissue using the same medical device. Additionally, aspects of the invention allow a user to use a medical device to deliver energy with electrodes to tissue to ablate, cut, dissect, ablate, mark, or otherwise treat tissue. Aspects of the invention also allow a user to use a medical device to deliver energy to tissue with larger electrode surface areas to coagulate, cauterize, or otherwise treat tissue in hemostasis procedures without removing the medical device from the treatment site. Additionally, aspects of the invention allow a user to use a medical device to deliver fluids to a treatment site without removing the medical device from the treatment site. Some aspects of the invention may be used in performing procedures using endoscopes, laparoscopes, arthroscopes, and the like.

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the invention as described above and illustrated in the accompanying drawings will now be described in detail. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0018] The terms "proximal" and "distal" are used herein to refer to the relative location of components of an exemplary medical device. As used herein, "proximal" refers to a location relatively close to the outside of the body or close to the medical professional using the medical device. In contrast, "distal" refers to a location relatively far from the medical professional using the medical device or close to the inside of the body. As used herein, the words "comprises," "comprising," "having," "including," or other variations thereof are intended to cover a non-exclusive inclusion, such that a device or method that includes a list of elements may include those elements as well as other elements not expressly listed or inherent thereto. Unless otherwise indicated, the term "exemplary" is used in the sense of "example" rather than "ideal." As used herein, the terms "about," "substantially," and "approximately" indicate a range of values ​​within + / - 10% of the stated value.

[0019] 1A and 1B show a medical device 10 including a handle 12, a shaft 14, and a distal end 16. The handle 12 includes a body 18 and a movable body 20. The handle 12 also includes a port 22 configured to receive a fluid, and a hub 24 configured to receive electrical energy, similar to an electrical plug or socket. The distal end 16 includes an electrode 26 and an end cap 42. The electrode 26 is an active electrode electrically connected to the hub 24 and includes one or more lumens (FIG. 3C) fluidly connected to the port 22. As will be described in more detail below, the end cap 42 includes a passive conductive portion that is energized when contacted by the electrode 26. The medical device 10 is inserted into a body cavity of a patient via an insertion device (not shown) or alone, with at least a portion of the shaft 14 inside the patient's body and the handle 12 remaining outside the patient's body. A user can manipulate the handle 12 from outside the patient's body. For example, movement of the movable body 20 in a first direction relative to the body 18 extends the electrode 26 relative to the shaft 14 (e.g., moves the electrode 26 in a distal direction relative to the distal end of the shaft 14 and the end cap 42), and movement of the movable body 20 in a second direction relative to the body 18 retracts the electrode 26 relative to the shaft 14 (e.g., moves the electrode 26 in a proximal direction relative to the distal end of the shaft 14 and the end cap 42).

[0020] The handle 12 is connected to a fluid source through a port 22. The port 22 is in communication with the electrode 26 through an internal lumen 27 that extends through the shaft 14. For example, as shown in FIG. 1B, the internal lumen 27 extends longitudinally through the body 18 of the handle 12, and the port 22 includes a port lumen 22A that extends through the port 22 and communicates the port 22 with the internal lumen 27. The fluid source may include a container or reservoir, such as an irrigation bag, vial, syringe, etc., of saline or other fluid. The fluid source may pressurize the fluid via a pressure source, such as a pump, a syringe needle, a gravity drip, etc. The fluid source may be user controlled via a control device, such as a trigger, a foot pedal, an adjustable dial, etc., and / or may provide an automatic or constant irrigation supply. The port 22 may be located on a distal portion of the body 18 or on the movable body 20. Additionally, port 22 may include a one-way valve 28, luer, seal, threads 30, or any suitable element to maintain a secure connection between handle 12 and a fluid source, minimize or prevent backflow (e.g., fluid flow proximally out of port 22), and / or minimize or prevent leakage. In one example, one-way valve 28 includes an outer housing that includes an inner elastomeric and / or gelatinous sealing member (not shown).

[0021] The handle 12 is connected to an energy source via a hub 24. The hub 24 is electrically connected to the electrode 26 via a conductive element in the shaft 14. The energy source may be an electrocautery source, an RF generator, a heating source, a current generator, or the like. In one embodiment, the medical device 10 is used for monopolar electrosurgical procedures and may include a return electrode located remotely from the electrode 26. Alternatively, the medical device 10 is used for bipolar electrosurgery. Although described with a fluid source, the energy source may include any control element that allows a user to control the delivery of energy. The hub 24 is disposed on the movable body 20 or body and includes one or more pins, or prongs 32 for connecting to an energy source. In one embodiment shown in FIG. 1B, the prongs 32 extend through the hub 24 in a direction transverse to the longitudinal axis of the handle 12 and are electrically and physically connected to a conductive element 33, such as a wire, cable, and / or braided sheath. The conductive element 33 is electrically conductive or includes a conductive element that extends longitudinally through the inner lumen 27 and the shaft 14. As shown in FIG. 1B, fluid delivered through the port 22 surrounds at least a portion of the conductive element 33. In another embodiment, the energy source may be part of the handle 12.

[0022] As described above, the handle 12 can control the extension or retraction of the electrode 26 relative to the distal end 16 and end cap 42 of the shaft 14. For example, the body 18 includes a slot 34 and a thumb ring 36. The moveable body 20 is slidably disposed within the slot 34 and includes one or more finger holes 38. The moveable body 20 is connected to a drive element that moves at least a portion of the electrode 26 distally or proximally based on relative movement between the body 18 and the moveable body 20. In one aspect, the conductive element 33 is a drive wire, rod, cable, or the like that moves at least a portion of the electrode 26 distally or proximally while connecting the electrode 26 to the hub 24, e.g., one or more prongs 32, to deliver energy to the electrode 26. Although not shown, the handle 12 includes a locking mechanism for selectively fixing the movable body 20 at a predetermined position along the slot 34 and / or within a predetermined range of positions along the slot 34 to releasably fix the relative positions of the body 18 and the movable body 20, and thus the relative positions of the electrode 26 and the shaft 14.

[0023] The shaft 14 extends from a distal portion of the body 18 to the distal end 16 and surrounds at least a portion of the electrode 26. The shaft 14 is coupled to the handle 12 via a coupler 40, which surrounds a portion of the shaft 14 and is threaded into the body 18 to secure the elements. The shaft 14 is a sheath that surrounds a central lumen and at least a portion of the drive wire. In another embodiment, the shaft 14 may be an extruded member that includes one or more lumens that extend from the handle 12 to the distal end 16. In either embodiment, the shaft 14 may be electrically insulated and fluidically isolated from the elements disposed within the shaft 14 to protect the user and patient.

[0024] 2A and 2B show further aspects of the distal end 16. Note that FIGS. 2A and 2B show a portion of the shaft 14 as transparent to show the internal components of the distal end 16.

[0025] 2A and 2B show perspective views of a portion of the distal end 16, with a portion of the electrode 26 disposed within an end cap 42 of the distal end 16. The end cap 42 includes a distal end 44 and one or more inner portions 46. The end cap 42 may be a separate component attached to the shaft 14 or may be integrally formed with the shaft 14. Although not shown, the inner portion 46 may include one or more graduated surfaces of different radii or sizes, which may aid in attachment of the end cap 42 to the shaft 14. In one embodiment, the distal end 44 is electrically conductive and the one or more inner portions 46 are at least partially electrically insulating. For example, the distal end 44 is formed of a conductive material, such as a metal, and the inner portion 46 is a ceramic material or another non-conductive material. In another embodiment, the distal end 44 includes a metallic or conductive coating on the outside of a non-conductive material, such as a ceramic material. The distal end 44 is a passive electrode with no dedicated conductive element. For example, when electrode 26 is energized and extended as described above, electrode 26 does not contact distal end 44 and distal end 44 is not energized. However, when electrode 26 is energized and retracted, electrode 26 contacts distal end 44 and distal end 44 is energized. As shown, distal end 44 includes a generally cylindrical shape with a flat distal end face and rounded distal edges. In one aspect, the entire distally facing surface of end cap 42 is electrically conductive. End cap 42 and distal end 44 also include a central opening 52, as described below.

[0026] The end cap 42 includes an outer insulating member 48 that radially surrounds a portion of the distal end 44. The end cap 42 also includes an inner insulating member 50. The inner insulating member 50 is radially disposed within the end cap 42, e.g., radially within the distal end 44, and surrounds the central opening 52 to at least partially insulate the distal end 44 from the portion of the electrode 26 disposed within the central opening 52. The outer insulating member 48 and the inner insulating member 50 may each be formed of a ceramic material, an elastomeric polymeric material, or another non-conductive material.

[0027] 2A, the end cap 42 includes a central opening 52 through which the electrode 26 is disposed. The central opening 52 is larger (e.g., has a larger diameter) than the electrode 26 to form a gap between the distal end 44, the inner insulating member 50, and the electrode 26. The gap formed by the central opening 52 may help to electrically insulate the distal end 44 from the electrode 26 when the electrode 26 is in the extended position.

[0028] The electrode 26 is coupled to a proximal support 54 at the distal end 16, which includes a cylindrical extension 56. The proximal support 54 is coupled to a portion of the electrode 26 to overlap and extend distally of the electrode 26 to receive at least a portion of the electrode 26. The electrode 26 and the cylindrical extension 56 can be coupled via any suitable means, such as welding, adhesive, crimping, friction fit, or the like. The electrode 26 and the proximal support 54 move relative to the end cap 42 in response to relative movement of the movable body 20 and the body 18 of the handle 12. For example, when the movable body 20 is in a proximal position relative to the body 18, the electrode 26 is substantially retracted within the end cap 42, with only a distal portion of the electrode 26 (e.g., the distal tip 60) extending distally beyond the end cap 42 (FIG. 2B). In the retracted position shown in FIG. 2B, a portion of the electrode 26 is in contact with and electrically connected to the distal end 44. Next, when the movable body 20 is moved distally relative to the main body 18, the electrode 26 and the proximal support 54 are moved distally relative to the end cap 42, and a majority of the electrode 26 is extended distally through the central opening 52 and beyond the end cap 42 (FIG. 2A).

[0029] The electrode 26 includes a distal tip 60 and a longitudinal portion 62. The distal tip 60 is wider than the longitudinal portion 62, which is wider than the central opening 52 through the end cap 42 as described above, the width being measured in a direction transverse to the longitudinal portion 62 and the longitudinal axis of the medical device 10. As shown in FIG. 3C, the electrode 26 also includes an electrode lumen 64 extending through the longitudinal portion 62. The electrode lumen 64 is in communication with the port 22 through at least one lumen 70 via the proximal support 54. In one aspect, the inner sheath 41 forms at least a portion of the communication between the lumen 70 and the port 22. Additionally, the electrode lumen 64 is in fluid communication with an outlet 66 in the distal tip 60 that allows fluid to flow from the electrode lumen 64. In one aspect, the outlet 66 is circular and centrally located on the most distal surface of the distal tip 60.

[0030] Although not shown, the electrode 26 may include any number of outlets 66, and the outlets 66 may be located at any position and in any orientation on the electrode 26 for delivery of fluid to the body cavity. Additionally, although the invention describes contact between the electrode 26 and the distal end 44 as being formed by a proximal portion (e.g., the most proximal surface) of the distal tip 60 contacting a distal end surface of the distal end 44, the invention is not so limited. For example, in one aspect, the length 62 of the electrode 26 has a radial extension that extends through an opening in the inner insulating member 50 or otherwise electrically connects the electrode 26 and the distal end 44 when the electrode 26 is retracted.

[0031] 3A and 3B are side views and 3C are cross-sectional views of a portion of distal tip 16. Note that Figures 3A and 3B show a portion of shaft 14 in transparent form to show the internal components of distal tip 16.

[0032] 3A and 3B, the electrode 26 includes an extended configuration (FIG. 3A) and a retracted configuration (FIG. 3B). In the extended configuration, the distal tip 60 extends distally beyond the distal end 44. In the retracted configuration, a portion of the distal tip 60 (e.g., the annular most proximal surface) abuts and is electrically connected to the distal end 44. Additionally, it should be noted that the relative sizes of the electrode proximal support 54 and the inner portion 46 of the end cap 42 may limit the distal extension of the electrode 26 (FIG. 3A).

[0033] The electrode 26 includes a shape in which the distal tip 60 is wider than the longitudinal portion 62 when measured in a direction transverse to the longitudinal axis of the medical device 10. For example, the electrode 26 includes a generally T-shaped cross-sectional shape. The electrode 16 may include different shapes. In either embodiment, the distal tip 60 contacts the distal end portion 33 when the electrode 26 is in the retracted configuration, so that when the electrode 26 is in the retracted configuration and energized, the distal end 44 is also energized. On the other hand, when the electrode 26 is in the extended configuration and energized, the gap formed by the central opening 52 together with the inner insulating member 50 prevents the distal end 44 from also being energized.

[0034] 3C illustrates a cross-sectional shape of distal portion 16. As shown, electrode 26 is supported proximally by proximal support 54. Proximal support 54 includes drive wire receiver 58. Drive wire receiver 58 is a recess or indentation that extends parallel to at least a portion of lumen 70. Drive wire receiver 58 receives a portion of a drive wire (e.g., wire 33) such that movement of moveable body 20 imparts distal or proximal movement to proximal support 54 and electrode 26. The drive wire is coupled to drive wire receiver 58 in coupling portion 72 by welding, adhesive, crimping, friction fit, or any other permanent or temporary connection. Proximal support 54 is also coupled to electrode 26 by welding, adhesive, crimping, friction fit, or any other permanent or temporary connection. In one aspect, both the drive wire and the proximal support 54 are electrically conductive and electrically connect one or more prongs 32 of the hub 24 to the electrode 26. In another aspect, the proximal support 54 may be at least partially insulated and include another conductive element, such as a wire, that electrically connects the drive wire to the electrode 26. Similarly, in one aspect, the drive wire may be at least partially insulated and include another conductive element, such as a wire. Additionally, at least a portion of the drive wire is disposed within the inner sheath 41. Alternatively, the drive wire is disposed within a separate lumen within the shaft 14 (e.g., a lumen separate from the lumen extending through the inner sheath 41).

[0035] The end cap 42 includes a central lumen 74 through which the electrode 26 can move during extension or retraction. The end cap 42 also includes a reduced diameter portion, or stop surface 76, at the distal end of the central lumen 74. The electrode 26 includes an enlarged diameter portion 78 between the first longitudinal portion 80 and the second longitudinal portion 82 of the length 62. The diameter of at least a portion of the enlarged diameter portion 78 is greater than the diameter of the stop surface 76. The stop surface 76 and the enlarged diameter portion 78 may limit the distal extension of the electrode 26 through the end cap 42. Additionally, the inner insulating member 50 extends proximally to the stop surface 76 to insulate the distal end 44 from the electrode 26 when the electrode 26 is in the extended position. Additionally, although not shown, the end cap 42 may be secured to the shaft 14 via welding, adhesive, crimping, friction fit, or other suitable coupling.

[0036] When the electrode 26 is in an extended position (FIG. 2A), the first longitudinal portion 80 of the electrode 26 protrudes from the end cap 42 to form an exposed portion. The electrode 26 is energized, and the exposed portion is used to ablate, cut, dissect, ablate, mark, or otherwise treat tissue. When the electrode 26 is in a retracted position (FIG. 2B) and energized such that both the electrode 26 and the distal end 44 are energized, the distal tip 60 and the distal end 44 may form a larger energized portion of the medical device 10 that may be used to coagulate, cauterize, or otherwise treat tissue. For example, the electrode 26 is extended and energized to perform a precise ablation or marking procedure. The size and shape of the electrode 26 helps to reduce the risk of delivering energy to an unintended portion of tissue. For example, the distal tip 60 includes an outer diameter of about 0.8 mm, measured transverse to the longitudinal axis of the medical device 10, and the electrode outlet 66 includes a diameter of about 0.3 mm, measured transverse to the longitudinal axis of the medical device 10. Additionally, the electrode 26 can be retracted and energized to perform a hemostatic procedure. The size of the energized portion formed by the distal tip 60 and the distal end 44 can be equal to or greater than the diameter of a blood vessel in the tissue to be treated. In one embodiment, the distal end 44 includes a major diameter (e.g., extending from opposite sides of the radially outward surface) of about 1.55 mm, measured transverse to the longitudinal axis of the medical device 10, and a minor diameter (extending from opposite sides of the distal end surface) of about 0.75 mm, measured transverse to the longitudinal axis of the medical device 10. The central opening 52 includes a diameter slightly larger than the diameter of the longitudinal portion 62 of the electrode 26, but may be slightly smaller than the diameter of the distal tip 60. In this embodiment, the distal end 44 is approximately 1.44 mm 2 2.2 mm。 Additionally, end cap 42 includes a diameter, measured transverse to the longitudinal axis of medical device 10, of approximately 2.2 mm. Thus, medical device 10 can be used to perform resection and hemostatic procedures without removing medical device 10 from the body cavity, thereby reducing surgical time and minimizing risk to the patient.

[0037] Additionally, the medical device 10 can be used to deliver fluids to the body cavity. For example, the medical device 10 can inject fluids into the submucosal surface of the treatment site via the outlet 66, which can form a bleb or cushion under the tissue being treated. The fluid can be injected prior to, during, or after the resection or hemostatic procedure, without requiring replacement of the device.

[0038] 4 is a flow diagram illustrating an exemplary tissue treatment method 400 for applying energy for at least one tissue resection or ablation procedure. Method 400 includes step 402, in which a user places a distal portion of a medical device adjacent to or within tissue. Step 402 may include a preliminary step of injecting fluid into the tissue via a separate conventional needle injector or outlet 66. The preliminary injection may separate or dilate one or more layers of tissue below or including the affected portion of the tissue to lift the affected tissue from the underlying tissue layers, thereby creating a tissue bleb. Step 402 also includes delivering the medical device via the insertion device.

[0039] At step 404, a user can extend the electrode distally from a distal portion of the medical device. For example, the medical device is delivered to tissue via an insertion device with the electrode retracted proximally. Step 404 includes extending the electrode 26 by acting on the moveable body 20 of the handle 12 relative to the body 18, as described above.

[0040] In step 406, a user can apply the energized electrode to tissue to deliver energy to the electrode and ablate, cut, dissect, ablate, mark, or otherwise treat the tissue. Further, energy is delivered to the electrode 26 from an energy source, which can be controlled by a user interface.

[0041] At step 408, the user may retract the electrode in a proximal direction toward a distal portion of the medical device. For example, step 408 may include retracting the electrode 26 by action on the moveable body 20 of the handle 12 relative to the body 18, as described above. At step 408, the electrode 26 is retracted such that one or more portions of the distal tip 60 contact the distal end 44. As a result, any energy delivered to the electrode 26 also energizes the distal end 44, dispersing the delivered energy and enlarging the energized portion of the medical device 10. The larger energized portion formed by the electrode 26 and the distal end 44 may be larger than a blood vessel in the tissue being treated.

[0042] Next, method 400 includes step 410 where the user can again deliver energy to the electrode. When electrode 26 is in the retracted position, energy is delivered through electrode 26 and distal end 44. Electrode 26 and distal end 44 can be applied to tissue to coagulate, cauterize, or otherwise treat the tissue.

[0043] In one aspect, the user can extend the electrode 26 and deliver energy to the electrode 26 (distal end 44 is separated) to precisely ablate tissue with reduced risk of thermal perforation to the surrounding area of ​​the body cavity. If hemostasis is required, the user can retract the electrode 26 proximally so that a portion of the electrode 26 (e.g., the distal tip 60) contacts the distal end 44, thereby energizing the previously unenergized distal end 44. When both the electrode 26 and the distal end 44 are energized, the medical device 10 creates a larger energized surface area, allowing for more effective hemostasis. For example, the surface area of ​​the distal tip 60 and distal end 44 is larger than the blood vessel requiring hemostasis, and therefore may cauterize or coagulate blood more effectively than if only the electrode 26 was energized and applied to the tissue.

[0044] Based on the type of medical procedure and the progress of the tissue treatment, the user can repeat the steps of method 400 as many times as necessary to perform the tissue treatment procedure. For example, the user can return to step 402 from step 410. The user can extend and retract the electrode 26 to alternate between ablation and coagulation procedures. The user can also reposition the distal end 16 and perform method 400 as many times as necessary to perform the tissue treatment procedure. Additionally, during any of the above steps, the user can deliver a fluid to the tissue. The fluid is delivered from a fluid source through the port 22, the port lumen 22A, the inner lumen 27, the support lumen 70, and the electrode lumen 64 to one or more outlets 66 of the electrode 26. For example, the fluid can be delivered to create, re-create, maintain, and / or expand a bleb in the tissue. The energy and fluid delivery described in method 400 can be simultaneous or staggered depending on the medical procedure. Additionally, the medical device 10 can be used to perform any of the above procedures without the need to remove and replace the medical device 10 from the body cavity, thereby reducing overall surgical time and risk to the patient.

[0045] While the principles of the invention have been described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those skilled in the art and with access to the disclosure provided herein will recognize that additional modifications, applications, embodiments, and equivalent substitutions are all within the scope of the embodiments described herein. Thus, the invention should not be considered as limited by the above description.

Claims

1. a shaft having a distal end including a passive electrode defining a central opening extending therethrough; an active electrode within the central opening; Equipped with The active electrode includes at least an extended position in which the active electrode does not contact the passive electrode; The medical device is movable between a retracted position in which the active electrode contacts the passive electrode.

2. when the active electrode is energized in the extended position, the passive electrode is not energized; The medical device of claim 1 , wherein the passive electrode is energized when the active electrode is energized in the retracted position.

3. 3. The medical device of claim 1 or 2, wherein the passive electrode is generally cylindrical in shape with a flat distal end face and at least one rounded distal end.

4. The medical device of any one of claims 1 to 3, further comprising an outer insulating member surrounding at least a portion of the passive electrode.

5. The medical device of any one of claims 1 to 4, further comprising an inner insulating member within the central opening and between the active electrode and the passive electrode.

6. 6. The medical device of claim 1, further comprising a handle having a body portion and a movable portion, at least one of the body portion and the movable portion comprising a slot, the active electrode being extended by sliding the movable portion relative to the body portion in a first direction, and the active electrode being retracted by sliding the movable portion relative to the body portion in a second direction.

7. 7. The medical device of claim 6, wherein at least one of the body portion and the movable portion has a fluid port for connecting a fluid source to a handle, and at least one of the body portion and the movable portion includes a hub for connecting an energy source to the handle.

8. 8. The medical device of claim 7, further comprising a drive element extending from the handle to the active electrode, electrically connecting the energy source to the active electrode, and moving the active electrode in a distal or proximal direction based on relative movement between the body portion and the movable portion.

9. The medical device of any one of claims 1 to 8, wherein the entire distal-most surface of the passive electrode is conductive.

10. The medical device of any one of claims 1 to 9, wherein the active electrode comprises a distal tip and a longitudinal shaft.

11. The medical device of claim 10 , wherein in the retracted position, only a proximal face of a distal tip of the active electrode contacts the passive electrode.

12. The medical device of claim 10 , wherein the distal tip comprises a width, as measured across a longitudinal axis of the medical device, that is greater than a width of the longitudinal shaft.

13. The medical device of claim 10 , wherein the distal tip includes a width, as measured across a longitudinal axis of the medical device, that is greater than a diameter of the central opening.

14. 14. The medical device of claim 1, wherein the shaft includes a central lumen that directs fluid flow therethrough, and the active electrode includes an electrode lumen in communication with the central lumen, the electrode lumen receiving fluid flow from the central lumen and directing the fluid distally through an opening.

15. 15. The medical device of claim 1, wherein the distal end includes a cap having a reduced diameter stop surface radially surrounding a portion of the active electrode, the active electrode including an enlarged portion proximal to the distal end of the active electrode, the reduced diameter stop surface of the cap and the enlarged portion of the active electrode limit distal extension of the active electrode, and the medical device further includes an insulating member radially inward of the reduced diameter stop surface of the cap.

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