Medical system for tissue ablation

Abstract

The medical system can include a catheter (101) for ablating tissue, the catheter (101) including a flexible longitudinal body including a distal end and a distal portion extending distally from the distal end of the longitudinal body. The distal portion can include a plurality of electrodes (103). The medical system can also include one or more control units (112) coupled to the catheter, the one or more control units (112) configured to (1) control the delivery of electrical energy to each of the plurality of electrodes and (2) automatically control the position of the distal portion of the catheter.

Description

Technical Field

[0001] Various aspects of the present disclosure generally relate to tissue resection, including radiofrequency ablation of tissue. More particularly, at least certain embodiments of the present disclosure relate to systems, devices, and related methods for resection of tissue, among other aspects.

Background Art

[0002] Due to technological advancements, users of medical systems, devices, and methods have been able to perform increasingly complex procedures on subjects. Tissue resection often involves, for example, using a device that transmits radiofrequency energy to excise tissue. In some examples, a user can implement a radiofrequency ablation treatment algorithm that is controlled by setting a certain power and resection time period for treating the desired tissue. The tissue resection zone from this method can be a rough estimate of the tissue requiring treatment because the clinician does not have direct visualization during treatment and the feedback during and after treatment for confirming accurate treatment of the targeted tissue can be limited. In some examples, as a result of such treatment algorithms, the number of injuries associated with electrosurgery can increase. For example, a portion of healthy tissue may be inadvertently resected. Electrosurgical devices and systems are needed to address this and / or other difficulties.

Summary of the Invention

Means for Solving the Problems

[0003] Aspects of the present disclosure relate, inter alia, to systems, devices, and methods for resection of tissue. Each of the aspects disclosed herein can include one or more of the features described in relation to any of the other disclosed aspects.

[0004] The medical system can include a catheter for excising tissue, the catheter including a flexible longitudinal body including a distal end portion and a distal portion extending distally from the distal end portion of the longitudinal body. The distal portion can include a plurality of electrodes. The medical system can also include one or more control units coupled to the catheter, the control units being configured to (1) control the supply electrical energy to each of the plurality of electrodes and (2) automatically control the position of the distal portion of the catheter.

[0005] Any of the systems and devices disclosed herein can have any of the following features. The drive system may be configured to move the catheter proximally and distally and may communicate with and be controlled by one or more control units. A generator may be coupled to and controlled by one or more control units to provide electrical energy to each of a plurality of electrodes. And a scanning device may be configured to create an image of a patient's anatomical structure. One or more control units may be configured to monitor the impedance of each of the plurality of electrodes and adjust the electrical energy supplied to each of the plurality of electrodes based on the monitored impedance. A graphical user interface may be configured to enable a user to select an area of tissue targeted for ablation by the plurality of electrodes. One or more control units may be configured to adjust the amount of electrical energy supplied to at least one of the plurality of electrodes based on at least one image created by the scanning device. One or more control units can include a plurality of stored ablation patterns, and each stored ablation pattern can include an output energy level for each of the plurality of electrodes. The catheter can include an internal element extending from a proximal portion to a distal portion of the catheter. The internal element can include a distal protrusion having a radially outermost surface that contacts a radially inner surface of the distal portion, the internal element can be disposed within the distal portion and the longitudinal body and be movable relative to the distal portion and the longitudinal body, and the internal element can be configured to transmit electrical energy to each of the plurality of electrodes independently of the others of the plurality of electrodes. The catheter can include an ultrasonic probe disposed within the distal portion. The scanning device can be configured to detect the position of the ultrasonic probe. The distal portion of the catheter may be expandable and can include an inner portion and an outer surface, and each of the plurality of electrodes extends from the inner portion to the outer surface. The distal portion of the catheter may be cylindrical and can include a conical distal portion and a conical proximal portion.And the plurality of electrodes can form a lattice pattern around the outermost portion in the radial direction of the distal portion. The distal protrusion may be configured to independently activate each of the plurality of electrodes when contacting each electrode, and the distal protrusion may be configured to translate longitudinally and rotate with respect to the distal portion. Each of the plurality of electrodes may not be connected to the proximal lead wire, and the distal protrusion may be curved. The drive system can include a plurality of motors for translating the catheter longitudinally and rotating the catheter about the longitudinal axis of the catheter. One or more control units can be configured to independently supply electrical energy to each of the plurality of electrodes.

[0006] In another example, a medical system can include a catheter for excising tissue, the catheter including a flexible longitudinal body including a distal end portion, and a distal portion extending distally from the distal end portion of the longitudinal body, the distal portion including a plurality of electrodes. The medical system can also include one or more control units coupled to the catheter, the control units being configured to (1) independently supply electrical energy to each of the plurality of electrodes and (2) automatically control the position of the distal portion of the catheter. The medical system can further include a drive system configured to move the catheter proximally and distally. The drive system can communicate with and be controlled by one or more control units. Also, the medical system can include a generator coupled to and controlled by one or more control units to provide electrical energy to each of the plurality of electrodes.

[0007] Any of the systems or devices disclosed herein can have any of the following features. The distal portion of the catheter may be expandable, may include an inner portion and an outer surface, and each of the plurality of electrodes can extend from the inner portion to the outer surface.

[0008] A method for treating tissue can include positioning a distal portion of a catheter proximal to a treatment zone such that at least one electrode of a plurality of electrodes in the distal portion is adjacent to the treatment zone. The method can also include activating at least one electrode of the plurality of electrodes via a control unit to treat the tissue in the treatment zone. The method can further include automatically moving the distal portion of the catheter relative to the treatment zone and activating at least one other electrode of the plurality of electrodes via the control unit to treat the tissue in the treatment zone.

[0009] Any of the methods disclosed herein can include any of the following steps or features. The method can further include adjusting the amount of electrical energy supplied to at least one electrode of the plurality of electrodes based on the measured impedance of at least one electrode of the plurality of electrodes. The method can also include moving an internal component of the catheter relative to the distal portion to activate another electrode of the plurality of electrodes.

[0010] It can be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claimed invention. The accompanying drawings, which are incorporated herein and constitute a part of this specification, illustrate exemplary aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

Brief Description of the Drawings

[0011]

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[0012] The present disclosure is directed, among other aspects, to systems, devices, and methods for excising, incising, scraping, removing moisture from, or otherwise damaging or breaking tissue. Reference will now be made in detail to aspects of the present disclosure, examples of which are illustrated in the accompanying figures. Whenever possible, the same or similar reference numbers are used throughout the figures to refer to the same or like parts. The term "distal" refers to the portion that is furthest from the user when introducing the device into the patient's body. In contrast, the term "proximal" refers to the portion that is closest to the user when placing the device within the patient's body. As used herein, the terms "comprising," "comprises," or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not necessarily include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. The term "exemplary" is used in the sense of "an example" rather than "an ideal."

[0013] Embodiments of the present disclosure can be used to excise tissue within a body cavity or to facilitate the process thereof. In particular, some embodiments include an expandable or inflatable device that includes a plurality of electrodes. The device may be delivered to the target tissue through an endoscopic working channel or other structure for guiding the device, or may be delivered independently to the target tissue site without an endoscope. In some examples, the device may be sent distally from a proximal port, or may be sent in reverse through an endoscope, gastroscope, colonoscope, flexible catheter, or other medical device working channel before inserting the device into the patient's body. All or part of the devices discussed herein can be made of metal, composite materials, plastics, or can include any combination of shape memory metals (such as nitinol), shape memory polymers, polymers, or biocompatible materials.

[0014] FIG. 1 shows an exemplary surgical system 100 according to an embodiment of the present disclosure. The system 100 can include a catheter device 101, a scanning device 106, a control unit 112, a generator 110, a robotic computer control device 114, a display device 116, and a motor assembly 108. The catheter device 101 is configured to move through a body lumen of a patient and excise tissue using one or more electrodes 103 on an outer surface of a distal portion 102 of the catheter device 101. The catheter device 101 can be used during minimally invasive surgical procedures such as laparoscopic or endoscopic procedures, or any other suitable medical procedure. The catheter device 101 may be used for radiofrequency ablation and may be configured to apply a current generated by radio waves to tissue.

[0015] As shown in FIG. 1, the catheter device 101 can include a distal portion 102, a proximal extension 105, and one or more electrodes 103 disposed on the surface of the distal portion 102. The distal portion 102 may be cylindrical and can have proximally and distally tapered conical shapes. The proximal end of the distal portion 102 may be tapered radially inwardly towards the most proximal end, and the most proximal end may be coupled to the proximal extension. The distal portion 102 may be an expandable or inflatable body and can include a proximal lumen (not shown) that connects the lumen (not shown) of the proximal extension 105 to the internal cavity of the distal portion 102. One or more electrodes 103 can be disposed on the outer surface of the distal portion 102. In some examples, a plurality of electrodes 103 may be disposed on the surface of the distal portion 102 and may each be connected to a control unit 112 through one or more wires (leads) disposed within the proximal extension 105. In some examples, each electrode 103 can be connected to the control unit 112 through one or more wires or other conductors printed on the inner surface of the distal portion 102. In some examples, each electrode 103 may be individually controlled, and the electrodes 103 on the distal portion 102 may be alternately connected to juxtaposed positive or negative electrodes. For example, the distal portion 102 may be a bipolar device in which a positive electrode 103 is adjacent to a negative electrode 103. In some examples, the electrodes 103 can form a grid on the surface of the distal portion 102. The electrodes 103 can form a pattern on the surface of the distal portion 102 that extends circumferentially around the longitudinal axis of the distal portion 102. The pattern can include, for example, a plurality of longitudinally arranged rows of electrodes 103 and a plurality of circumferential rings of spaced-apart electrodes 103. In some examples, the electrodes 103 may be circular and / or the distal portion 102 can include at least 5, 10, 15, 20, 24, 50, or 100 electrodes 103. In some examples, the electrodes 103 can be evenly spaced in a grid pattern, such as a grid pattern that covers part or all of the radially outer surface of the distal portion 102 relative to the central longitudinal axis of the distal portion 102.In some examples, the electrodes 103 can be evenly spaced in a grid pattern only across the outermost surface in the radial direction of the distal portion 102 with respect to the central longitudinal axis of the distal portion 102. In some examples, each electrode 103 can protrude from the outer surface of the distal portion 102, and in other examples, each electrode can be coplanar with the outer surface of the distal portion 102. The outer surface of the distal portion 102 can be flexible, compressible, and / or bendable and can be configured to conform to the irregular surface of the patient's anatomical structure. Each electrode 103 can communicate with the control unit 112, whereby the control unit 112 can monitor the impedance and other electrical characteristics of each electrode 103 and control the power / current to each electrode 103.

[0016] The distal portion 102 can be expandable or expandable in another form, can include flexible and / or non-flexible materials, and can be fluidly connected to a lumen (not shown) that extends through the proximal extension 105. Air, saline, or another fluid can be introduced into the lumen to expand the distal portion 102. In other examples, the distal portion 102 can be rigid. The proximal extension 105 can be cylindrical and can be configured to translate, rotate, or move the distal portion 102 in another form through the body lumen. For example, the proximal extension 105 can be flexible and can be configured to bend through the tortuous path of the body lumen, and can also be rigid enough to translate the distal portion 102 through the body lumen when the proximal extension 105 is translated distally. The proximal portion of the proximal extension 105 can be coupled to the control unit 112.

[0017] The control unit 112 can be interfaced with the catheter device 101 to provide current to one or more electrodes 103 and can monitor the impedance of each electrode 103. The control unit 112 can be coupled to and communicate with the scanning device 106, the display device 116, the generator 110, the robotic computer control device 114, the motor 108, and / or the catheter device 101. The control unit 112 can be powered by an electrical outlet and / or an external source such as the generator 110. The control unit 112 can include buttons, knobs, touchscreens, one or more graphical user interfaces, or other user interfaces to control one or more processors of the control unit 112. In some examples, the display device 116 can provide a graphical user interface for the control unit 112 and can consist of one or more monitors for displaying data received from the control unit 112 or other devices of the system 100. The control unit 112 can be configured to allow a user to set the pattern of electrical stimulation applied to the catheter device 101, such as by changing the electrodes 103 to be charged, adjusting the placement of the catheter device 101 via the motor assembly 108, and / or applying a pre-set electrical stimulation pattern to the catheter device 101. For example, the control unit 112 can be configured to activate a group of electrodes 103 and supply power thereto in response to a user or algorithm selection. In some examples, the control unit 112 can be configured to independently adjust the power supplied to each electrode 103. The control unit 112 can be configured to receive and monitor information regarding the temperature, impedance, position, or other parameters of the catheter device 101 or components of the catheter device 101, such as one or more electrodes 103.

[0018] The motor assembly 108 can include one or more motors and can be configured to move the catheter device 101 through a body lumen of a patient. The motor assembly 108 can include one or more rotary motors and one or more translational motors and can be configured to receive a proximal portion of the catheter device 101. The motor assembly 108 may be configured to move the catheter device 101 (including translation and / or rotation) and can receive instructions from the control unit 112. The robotic computer control device 114 may be part of the control unit 112 or may be separate and connected to the control unit. In some examples, a user can interact with the robotic computer control device 114 via a mouse, knob, touch screen, or other user interface, etc., and the robotic computer control device relays the instructions directly to the motor assembly 108 or relays them to the motor assembly 108 through the control unit 112. In some examples, a user can insert a proximal portion of the catheter device 101 through the motor assembly 108 before coupling the proximal end of the catheter device 101 to the control unit 112. In some examples, the motor assembly 108 can provide means for robotically positioning the catheter device 101 within a target region of a patient's body.

[0019] The scanning device 106 may be a three-dimensional computed tomography (CT) scanning device, an ultrasonic scanning device, or any other type of scanning device for scanning a patient's anatomical structure, taking an image of the patient's anatomical structure, and / or storing an image of the patient's anatomical structure. The scanning device 106 may be configured to image a treatment zone within the patient's body and output the image to the control unit 112 for display. In some examples, the scanning device 106 may be configured to detect the catheter device 101 as the catheter device 101 moves through the patient's body. The scanning device 106 may be operably coupled to the control unit 112 such that the control unit 112 receives real-time images during a procedure in which the catheter device 101 is used. In some examples, the scanning device 106 may be configured to image the amount of tissue resection of the patient.

[0020] In some examples, a user can perform a procedure using system 100 by first imaging a treatment zone within a patient using imaging device 106. For example, the user can scan the patient's body using a computed tomography (CT) scan to generate, for example, a three-dimensional image of the patient's anatomical structure including a body lumen. The user can then use control unit 112 and display device 116 to display the three-dimensional image of the patient's anatomical structure via a graphical user interface (GUI). After the treatment zone is identified within the image, the user can then use the GUI to select an approximate amount of tissue to be treated (e.g., an approximate amount of tissue to be excised as shown within the image). In some examples, control unit 112 can then select and perform thresholding, registration, and matrix transformation of the image on the selected segment region of the target tissue. In some examples, thresholding of the image can include a method of identifying a collection of voxels according to an algorithm for identifying shapes by identifying voxels between specific color intensities (or threshold color intensities). Identification of the location of diseased tissue within a patient's body can be facilitated by using thresholding transformation of the image in combination with other image processing techniques known in the art to identify shapes based on voxel and / or pixel color intensities. In some examples, voxel and / or pixel color intensities can be correlated with tissue density within an image produced by a CT scanner.

[0021] Image registration can include, for example, a method of associating coordinates in a three-dimensional space with each voxel in an image by using an image from a first scan. Subsequently, a subsequent scan that creates a subsequent image may be compared to the first scan, and the coordinates of each voxel in the image from the subsequent scan may be compared to the coordinates of each voxel in the image from the first scan, whereby the user may be able to identify where in the three-dimensional space each voxel in the subsequent image is located. The method of image registration can also include applying a matrix transformation to obtain information regarding the translation and rotation of each voxel in space from an initial starting position shown in the first scan image to a new position shown in the image from the subsequent scan. This method can be implemented by any image processing means known in the art. Image registration can be used, among other things, to track the placement of diseased tissue.

[0022] For example, the control unit 112 can generate a graphical overlay of a desired treatment zone shown in one or more images of a patient's anatomical structure. After the user selects the treatment zone and the control unit 112 calculates the amount of tissue to be resected, the control unit 112 can calculate a resection plan. The resection plan can be a surgical plan for how to use the system 100, specifically the catheter device 101, to resect the treatment zone by specifying particular electrodes 103 of the catheter device 101 to be activated and a particular amount of electrical energy to be applied to each electrode after the distal portion 102 is positioned proximal to or within the treatment zone. For example, the resection plan can involve multiple overlapping resections of variable shape, depth, and length. In some examples, the resection plan is aimed at encompassing all of the treatment zone while minimizing the amount of healthy tissue to be resected. For example, the resection plan can include instructions for activating a particular group of electrodes 103 to create a resection zone shaped to target unhealthy tissue in the treatment zone. In some examples, the resection plan can include particular instructions for the motor assembly 108 for positioning the distal portion 102 within the treatment zone using the motor assembly 108. The resection plan can include instructions for a robotic computer controller 114 to execute to position the distal portion 102 of the catheter device 101 within the treatment zone. In some examples, the user can view the resection plan and, if necessary, adjust the resection plan via the GUI.

[0023] When executing the resection plan, the user can place the distal portion 102 proximal to and / or distal to the selected treatment zone. For example, the user can align the activation portion, or the portion of the distal portion 102 where the electrodes 103 are disposed, with the treatment zone. The user can monitor the placement of the distal portion 102 using the scanning device 106 and visualize the placement of the distal portion 102 within the patient's body via the display device 116. In some examples, the control unit 112 can create and store a reference point calculated using an image generated by the scanning device 106 of the position of the distal portion 102 in the treatment zone. The reference point or reference position may be the initial state and / or initial position of the distal portion 102 created using the first image from the first scan of the treatment zone. In some examples, the reference point or reference position may be the starting position identified by the user before treating the selected treatment zone. The reference point can be used by the control unit 112 to calculate the required movement of the distal portion 102 relative to the treatment zone.

[0024] After a reference point has been established and stored within the control unit 112, the control unit 112 can use the motor assembly 108 to move the catheter device 101 to the starting point of the treatment in accordance with the ablation plan outlined previously. In some examples, the control unit 112 can send commands to the motor assembly 108 to automatically move the catheter device 101, for example, without manual mechanical input from the proximal handle. After the catheter device 101, specifically the distal portion 102, has been positioned at the starting point, the control unit 112 can activate the generator 110 and supply energy at a predetermined power and voltage limit setting to a specific group of electrodes 103. By supplying a predetermined amount of energy to a specific selected group of electrodes 103, the system 100 can create an ablation of a shape similar to the planned shape established within the ablation plan. In some examples, the control unit 112 can measure real-time impedance feedback from each of the electrodes 103 and actively adjust the energy supplied to each of the electrodes 103 based on the measured impedance feedback. In some examples, the distal portion 102 of the catheter device 101 may be moved after the first shape of ablation has been applied to the treatment zone, and then the control unit 112 can supply a predetermined amount of energy to a different, specific selected group of electrodes 103. This process can be repeated until the entire treatment zone has been ablated. In some examples, the control unit 112 can automatically calculate a new ablation plan based on the measured impedance feedback from each of the electrodes 103.

[0025] After resection using the catheter device 101, the user can then use the scanning device 106 to acquire a CT or other medical image and compare the newly acquired image with the image used to create the resection plan. The image showing the targeted tissue (such as diseased tissue) and the image showing the resected tissue are then aligned and compared to quantify the extent of the resection treatment and confirm that all of the required tissue has been resected. If a portion of the target tissue remains, the user can then create a new resection plan to resect the remaining tissue.

[0026] Figures 2A - 2D show various resection patterns created by selecting specific electrodes 203 of the activating catheter device 101. Each resection zone 214, 215, 220, 225, 230 can represent a portion of the resected tissue and each resection zone 214, 215, 220, 225, 230 can be formed via adjustment of the electrical energy supplied to each electrode 203 and movement of the distal portion 202. Figure 2A shows a catheter device 201 including a distal portion 202, an electrode 203, and a proximal extension 205, and a resection pattern 213. The resection pattern 213 includes a central region 214 and two lateral regions 215, and the central region 214 has a maximum resection depth with respect to the lateral regions 215. The radially outermost edge of the resection pattern 213 is curved. The electrical energy supplied to each electrode 203 may be variable and the distal portion 202 may be moved to form the resection pattern 213.

[0027] Figure 2B shows the catheter device 201 and a resection pattern 219 including eccentric resection zones 220 on both sides of the catheter device 201. The resection zones 220 can include two circular shapes disposed on both sides of the distal portion 202 and can include a curved radially outermost edge. Each portion of the resection zones 220 can be created by different groupings of the electrodes 203 of the distal portion 202. The portions of the resection zones 220 can be semi - circular in shape.

[0028] FIG. 2C shows a catheter device 201 and an ablation pattern 224 that includes a helical ablation zone 225. The ablation zone 225 can be formed by a plurality of electrodes 203 disposed around the surface of the distal portion 202. The ablation zone 225 can wrap around the distal portion 202 and, in some examples, can ablate a circumferentially extending portion of tissue around a body lumen. The ablation pattern 224 may be helical and / or corkscrew-shaped.

[0029] FIG. 2D shows a catheter device 201 and an ablation pattern 229 that includes a steerable ablation zone 230 that increases radially outward from the longitudinal axis of the catheter device 211 as the ablation zone 230 extends from the proximal end of the distal portion 202 to the distal end of the distal portion 202. The distal portion of the ablation zone 230 may be larger than the proximal portion of the ablation zone 230, and the ablation zone 230 can form one or more triangular shapes. In some examples, the ablation zone 230 can taper toward a point at one or more of its most proximal ends. To form the ablation zone 230, the energy applied to the most distal electrode 203 can be greater than the energy applied to the most proximal electrode 203. In other examples, the ablation pattern can include a proximal portion that is larger relative to the distal portion of the ablation pattern, and the ablation pattern can taper radially inward toward the central longitudinal axis of the catheter device as the ablation pattern extends distally.

[0030] Figures 2A - 2D are exemplary, and various different ablation patterns can be created using the plurality of electrodes 203 of the catheter device 201 and adjusting the energy output from each electrode 203. Additionally, movement of the catheter device 201, such as proximal, distal, or lateral translation, or rotation about the longitudinal axis, can enable the catheter device 201 to create additional variable ablation patterns. For example, part of the ablation plan can include rotating the catheter device 201 90 degrees clockwise and 90 degrees counterclockwise about its longitudinal axis, or at other rotation angles in either direction.

[0031] Figure 3 shows a catheter device 301 including a distal portion 302, electrodes 303, and a proximal extension 305, all disposed within a body lumen 345 of a patient. The tissue 350 surrounding the body lumen 345 includes a target zone 330. The distal section 331 of the treatment zone 330 requires ablation of different depths and shapes compared to the middle section 332 and proximal section 333 of the treatment zone 330. By adjusting the amount of energy applied to each electrode 303 and moving the catheter device 301 within the body lumen 345, the user can create an ablation pattern that aligns with the treatment zone 330 and targets the tissue of the treatment zone 330 without damaging the tissue adjacent to the treatment zone 330. Figure 3 shows an example of an irregularly shaped treatment zone. The ability to selectively activate and adjust the energy emitted from the plurality of electrodes 303 of the catheter device 301 provides the advantage of adjusting the ablation pattern based on the needs of the user and patient.

[0032] Figure 4 shows an alternative embodiment of a catheter device 401 that includes a distal portion 402, a plurality of electrodes 403, and a proximal extension 405. The catheter device 401 can have any of the features described herein in connection with the catheter devices 101, 201, 301. The catheter device 401 is substantially similar to the catheter device 101, except that each of the electrodes 403 is not connected to an individual corresponding wire leading to a control unit. Instead, each electrode 403 is commonly supplied with power / current by an internal element 460 that is shared by the electrodes 403. The internal element 460 can be cylindrical (e.g., a rod, wire, etc.), can be disposed within the distal portion, and can extend through the lumen of the proximal extension 405. The internal element 460 can include a distal protrusion 462 that extends radially outward from the longitudinal axis of the internal element 460 at the distal end of the element 460. The radially outermost surface 463 of the distal protrusion 462 can be configured to contact and slidably engage the internal surface 465 of the distal portion 402. For example, by rotation of the internal element 460 about its longitudinal axis and / or proximal or distal translation of the internal element 460, the radially outermost surface 463 of the distal protrusion 462 can be translated along the internal surface 465 of the distal portion 402 such that the radially outermost surface 463 remains in contact with the internal surface 465.

[0033] The proximal end of the inner element 460 may be configured to couple to the control unit 112 and may include a conductive material for transmitting electrical energy from the control unit 112 to the distal protrusion 462 of the inner element 460. When the radially outermost surface 463 of the distal protrusion 462 contacts one or more electrodes 403, the inner element 460 can transmit the electrical energy supplied by the control unit 112 to these one or more electrodes 403. For example, the distal protrusion 462 can form an electrical connection with one or more electrodes 403 when the distal protrusion contacts the inner surface of one or more electrodes 403. The inner element 460 can be moved proximally or distally and rotated about its longitudinal axis to position a particular electrode 403 for electrical activation. In some examples, the inner element 460 can translate continuously proximally and / or distally and / or rotate at a particular frequency to create an ablation pattern desired by the user. In some examples (not shown), the catheter device can include an inner element (similar to the inner element 460) having a plurality of protrusions (similar to the protrusion 462) that can contact a plurality of electrodes simultaneously, and in some examples, the catheter device can include a plurality of inner elements (similar to the inner element 460) that can contact a plurality of electrodes simultaneously.

[0034] FIG. 5 shows a front view of cross-section C of the catheter device 401. Arrow 470 indicates the rotation of the proximal protrusion 462 about the longitudinal axis of the inner element 460. The distal protrusion 462 may be curved as shown in FIG. 5 and can form a C-shape. In some examples, the distal protrusion 462 may be rigid, and in other examples, the distal protrusion 462 may be flexible. Each electrode 403 can include a surface that faces radially inward, and this surface remains exposed in the inner space of the distal portion 402 during operation of the catheter device 401, thereby allowing the radially outermost surface 463 of the distal protrusion 462 to contact each electrode 403 directly.

[0035] The catheter device 401 can operate in substantially the same manner as the catheter device 101 described above in this specification. In some examples, the proximal portion of the inner element 460 can be coupled to a motor assembly separate from the motor assembly used to control the positions of the distal portion 402 and the proximal extension 405. By using the inner element 460 to activate each electrode 403, the catheter device 401 may not require additional wiring from each electrode 403, and can facilitate the manufacture and miniaturization of the catheter device 401.

[0036] FIG. 6 shows another alternative embodiment of a catheter device 601 that includes a distal portion 602, a plurality of electrodes 603, and a proximal extension 605. The catheter device 601 can have any features described herein in connection with the catheter devices 101, 201, 301, 401. The catheter device 601 can include an ultrasonic probe 672 coupled to an internal member 670 disposed within the inner portion of the catheter device 601. The ultrasonic probe 672 can be disposed within the inner portion of the distal portion 602 and can emit ultrasonic signals. The ultrasonic probe 672 can be electrically connected to and communicate with a control unit 112 through, for example, a wire extending through the inner portion of the internal member 670. During operation, the signals emitted from the ultrasonic probe 672 can enable a user to monitor the position of the distal portion 602 within the patient's body by ultrasonic imaging. For example, the scanning device 106 can include an ultrasonic scanning device and can be used to monitor the position of the distal portion 602 within the patient's body during a procedure. By using the ultrasonic probe 672 when placing the distal portion 602 of the catheter device 601 within a treatment zone within the patient's body, the user can confirm the location of the distal portion 602 using ultrasonic imaging. In some examples, the ultrasonic probe 672 enables the user to create a three-dimensional map of the resection of the patient's tissue using ultrasonic imaging techniques.

[0037] By providing a catheter device that allows a user to selectively excise tissue and precisely adjust the power applied to a plurality of electrodes disposed in a treatment zone, the user can reduce damage to healthy tissue and avoid unnecessary harm to the patient's body caused by over-excision of tissue during a radiofrequency ablation procedure.

[0038] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed devices and methods without departing from the scope of the disclosure. Other aspects of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the features disclosed herein. It is intended that the specification and examples be considered as exemplary only.

Claims

1. A catheter for excising tissue, comprising: a flexible longitudinal body including a distal end portion; a distal portion extending distally from the distal end portion of the longitudinal body, the distal portion including a plurality of electrodes; and one or more control units coupled to the catheter and configured to (1) control the supply of electrical energy to each of the plurality of electrodes and (2) automatically control the position of the distal portion of the catheter. The catheter includes an internal element extending from a proximal portion of the catheter to the distal portion. The internal element includes a distal protrusion having a radially outermost surface that contacts a radially inner surface of the distal portion. The internal element is disposed within the distal portion and the longitudinal body and is movable relative to the distal portion and the longitudinal body. The internal element is configured to transmit electrical energy to each of the plurality of electrodes independently of other electrodes of the plurality of electrodes. A medical system, wherein the distal protrusion is configured to independently activate each of the plurality of electrodes when contacting each electrode.

2. The system of claim 1, wherein the distal protrusion is configured to translate longitudinally and rotate relative to the distal portion.

Images