Patent Application
20220387102
Various aspects of the present disclosure relate generally to tissue ablation, including radiofrequency ablation of tissue. More specifically, at least certain embodiments of the present disclosure relate to systems, devices, and related methods for ablating tissue, among other aspects.
Technological developments have given users of medical systems, devices, and methods, the ability to conduct increasingly complex procedures on subjects. The ablation of tissue, for example, often involves the use of devices transmitting radiofrequency energy in order to ablate the tissue. In some examples, a user may implement a radiofrequency ablation treatment algorithm governed by setting a constant power and ablation time period to treat the desired tissue. The tissue ablation zone from this method may be a rough estimate of tissue requiring treatment, as the physician may not have direct visualization during the treatment, and may have limited feedback during treatment and post treatment for confirming accurate treatment of targeted tissue. In some examples, such a treatment algorithm may result in an increase in the number of injuries related to electrosurgery. For example, a portion of healthy tissue may inadvertently be ablated. There is a need for electrosurgical devices and systems that address this and/or other difficulties.
Aspects of the disclosure relate to, among other things, systems, devices, and methods for ablating tissue. Each of the aspects disclosed herein may include one or more of the features described in connection with any of the other disclosed aspects.
A medical system may comprise a catheter for ablating tissue including a flexible longitudinal body including a distal end; and a distal portion extending distally from the distal end of longitudinal body. The distal portion may include a plurality of electrodes. The medical system may also comprise one or more control units coupled to the catheter and configured to (1) control a supply electrical energy to each of the plurality of electrodes and (2) automatically control a position of the distal portion of the catheter.
Any of the systems and devices disclosed herein may have any of the following features. A drive system may be configured to move a catheter proximally and distally, and the drive system may be in communication with and controlled by the one or more control units. A power generator may be coupled to and controlled by one or more control units for providing electrical energy to each of the plurality of electrodes; and a scanner may be configured to create images of a patient's anatomy. The one or more control units may be configured to monitor an 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 allow a user to select an area of tissue targeted for ablation by the plurality of electrodes. The one or more control units may be configured to adjust an amount of electrical energy supplied to at least one of the plurality of electrodes based on at least one image created by the scanner. The one or more control units may include a plurality of stored ablation patterns, and each stored ablation pattern may include output energy levels for each of the plurality of electrodes. The catheter may include an internal element extending from a proximal portion of the catheter to the distal portion. The internal element may include a distal protrusion with a radially-outermost surface in contact with a radially-inner surface of the distal portion, the internal element may be positioned within, and moveable relative to, the distal portion and the longitudinal body, and the internal element may be configured to transfer electrical energy to each of the plurality of electrodes independently of others of the plurality of electrodes. The catheter may include an ultrasound probe positioned within the distal portion. The scanner may be configured to detect the position of the ultrasound probe. The distal portion of the catheter may be expandable and may include an interior portion and an exterior surface, wherein each of the plurality of electrodes extends from the interior portion to the exterior surface. The distal portion of the catheter may be cylindrical and may include a conical distal portion and a conical proximal portion; and the plurality of electrodes may form a grid pattern around the radially-outermost portion of the distal portion. The distal protrusion may be configured to activate each of the plurality of electrodes independently when in contact with each electrode, and the distal protrusion may be configured to translate longitudinally and rotate relative to the distal portion. Each of the plurality of electrodes may not be connected to a proximal lead; and the distal protrusion may be curved. The drive system may include a plurality of motors to translate the catheter longitudinally and to rotate the catheter about a longitudinal axis of the catheter. The one or more control units may be configured to independently supply electrical energy to each of the plurality of electrodes.
In another example, a medical system may comprise a catheter for ablating tissue including a flexible longitudinal body including a distal end; and a distal portion extending distally from the distal end of longitudinal body, the distal portion including a plurality of electrodes. The medical system may also comprise one or more control units coupled to the catheter and configured to (1) supply electrical energy to each of the plurality of electrodes independently and (2) automatically control a position of the distal portion of the catheter. The medical system may further comprise a drive system configured to move the catheter proximally and distally. The drive system may be in communication with and controlled by the one or more control units. Also, the medical system may comprise a power generator coupled to and controlled by the one or more control units for providing electrical power to each of the plurality of electrodes.
Any of the systems or devices disclosed herein may have any of the following features. The distal portion of the catheter may be expandable and may include an interior portion and an exterior surface, and each of the plurality of electrodes may extend from the interior portion to the exterior surface.
A method of treating tissue may comprise positioning a distal portion of a catheter proximate to a treatment zone such that at least one electrode of a plurality of electrodes of the distal portion is adjacent to the treatment zone. The method may also comprise activating, via a control unit, the at least one electrode of the plurality of electrodes, to treat tissue of the treatment zone. The method may further comprise automatically moving the distal portion of the catheter relative to the treatment zone; and activating, via the control unit, at least one other electrode of the plurality of electrodes, to treat tissue of the treatment zone.
Any of the methods disclosed herein may include any of the following steps or features. The method may further comprise adjusting an amount of electrical energy supplied to at least one electrode of the plurality of electrodes based on a measured impedance of the at least one of the plurality of electrodes. The method may also comprise moving an internal component of the catheter relative to the distal portion to activate another electrode of the plurality of electrodes.
It may be understood that 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 aspects of the present disclosure and together with the description, serve to explain the principles of the disclosure.
The present disclosure is drawn to systems, devices, and methods for ablating, cutting, abrading, evaporating, or otherwise damaging or destroying tissue, among other aspects. Reference will now be made in detail to aspects of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same or similar reference numbers will be used through the drawings to refer to the same or like parts. The term “distal” refers to a portion farthest away from a user when introducing a device into a patient. By contrast, the term “proximal” refers to a portion closest to the user when placing the device into the patient. As used herein, the terms “comprises,” “comprising,” 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 “example,” rather than “ideal.”
Embodiments of the present disclosure may be used to ablate tissue in an endo-luminal space, or facilitate the process thereof. In particular, some embodiments include an expandable or inflatable device including a plurality of electrodes. The device may be delivered to target tissue through an endoscope working channel or other structure for guiding the device, or may be delivered independently, without an endoscope, to the target tissue site. In some examples, the device may be fed distally from a proximal port, or back-fed, through an endoscope, gastroscope, colonoscope, flexible catheter, or other medical device working channel prior to inserting the device into the body of the patient. All or parts of the devices discussed herein could be metallic, composite, plastic, or include a shape memory metal (such as nitinol), a shape memory polymer, a polymer, or any combination of biocompatible materials.
As shown in
Distal portion 102 may be inflatable or otherwise expandable, may include a compliant and/or a noncompliant material, and may be fluidly connected to a lumen (not shown) extending through proximal elongate 105. Air, saline, or another fluid may be input into the lumen to inflate distal portion 102. In other examples, distal portion 102 may be rigid. Proximal elongate 105 may be cylindrical and may be configured to translate, rotate, and otherwise move distal portion 102 through a body lumen. For example, proximal elongate 105 may be flexible and configured to bend through tortuous pathways of a body lumen, and may also be sufficiently rigid to translate distal portion 102 through a body lumen when proximal elongate 105 is translated distally. A proximal portion of proximal elongate 105 may be coupled to control unit 112.
Control unit 112 may be capable of interfacing with catheter device 101 to provide electrical current to the one or more electrodes 103 and monitor the impedance of each electrode 103. Control unit 112 may be coupled to, and in communication with, scanner 106, display 116, power generator 110, robot computer controller 114, motor 108, and/or catheter device 101. The control unit 112 may be powered by an external source such as an electrical outlet and/or power generator 110. Control unit 112 may include buttons, knobs, touchscreens, one or more graphical user interfaces, or other user interfaces to control one or more processors of control unit 112. In some examples, display 116 may provide a graphical user interface for control unit 112 and display 116 may consist of one or more monitors for displaying data received from control unit 112 or other devices of system 100. Control unit 112 may be configured to enable the user to set patterns of electrical stimulation to be applied to catheter device 101, such as by varying which electrodes 103 are electrified, adjusting the positioning of catheter device 101 via motor assembly 108, and/or applying pre-set electrical stimulation patterns to catheter device 101. For example, control unit 112 may be configured to activate and supply electrical power to groups of electrodes 103 depending on a user's or an algorithm's selection. In some examples, control unit 112 may be configured to adjust the electrical power supplied to each electrode 103 independently. Control unit 112 may be configured to receive and monitor information regarding the temperature, impedance, position, or other parameters of catheter device 101 or components of catheter device 101, such as one or more electrodes 103.
Motor assembly 108 may include one or more motors and may be configured to move catheter device 101 through a body lumen of a patient. Motor assembly 108 may include one or more rotational motors and one or more translational motors, and may be configured to receive a proximal portion of catheter device 101. Motor assembly 108 may be configured to move (including translate and/or rotate) catheter device 101 and may receive instructions from control unit 112. Robot computer controller 114 may be part of or separate of and connected to, control unit 112. In some examples, a user may interact with robot computer controller 114, such as via a mouse, knob, touchscreen, or other user interface, which relays instructions either directly to motor assembly 108 or through control unit 112 to motor assembly 108. In some examples, a user may insert a proximal portion of catheter device 101 through motor assembly 108 before coupling a proximal end of catheter device 101 to control unit 112. In some examples, motor assembly 108 may provide a means for robotically positioning catheter device 101 within a target area of a patient's body.
Scanner 106 may be a three dimensional computed tomography (CT) scanner, an ultrasound scanner, or any other type of scanner for scanning a patient's anatomy, taking images of a patients anatomy, and/or storing images of a patient's anatomy. Scanner 106 may be configured to image a treatment zone within a body of a patient, and output images to control unit 112 for display. In some examples, scanner 106 may be configured to detect catheter device 101 as catheter device 101 moves through a patient's body. Scanner 106 may be operatively coupled to control unit 112 so that control unit 112 receives real-time images during a procedure in which catheter device 101 is used. In some examples, scanner 106 may be configured to image an amount of ablation of a patient's tissue.
In some examples, a user may conduct a procedure using system 100 by first imaging a treatment zone within a patient's body using scanner 106. For example, a user may scan a patient's body using computed tomography (CT) scanning, and may generate three-dimensional images of a patient's anatomy including, for example, a body lumen. The user may then display, using control unit 112 and display 116, the three-dimensional images of the patient's anatomy via a graphical user interface (GUI). Once the treatment zone is identified in the images, the user may then select, using the GUI, an approximate volume of tissue for treatment (e.g. an approximate volume of tissue shown in the images to ablate). In some examples, control unit 112 may then select and implement the imaging thresholding, registration, and matrix transformations to segment areas of the selected target tissue. In some examples, imaging thresholding may include a method of identifying voxels between a certain color intensity (or threshold color intensity), and identifying clusters of voxels according to an algorithm for identifying shapes. Using imaging thresholding transformations, along with other image processing techniques known in the art, to identify a shape based on voxel and/or pixel color intensity may facilitate identification of the location of diseased tissue in a patient. In some examples, voxel and/or pixel color intensity may correlate to tissue density in an image produced by a CT scanner.
Image registration may include a method of associating a coordinate in three-dimensional space with each voxel in an image, for example by using an image from an initial scan. Subsequent scans creating subsequent images may then be compared to the initial scan, and the coordinates of each voxel in the images from subsequent scans may be compared to the coordinates of each voxel in the image from the initial scan, which may allow a user to identify where in three-dimensional space each voxel in a subsequent image is located. The method of image registration may also include applying a matrix transformation to obtain information on the translation and rotation of each voxel in space from an initial starting position shown in the initial scan image to a new position shown in an image from a subsequent scan. This method may be implemented by any image processing means known in the art. Image registration may be used to track the positioning of diseased tissue, among other aspects.
For example, control unit 112 may generate a graphical overlay of the desired treatment zone shown within one or more images of the patient's anatomy. Once the user has selected the treatment zone and the control unit 112 has calculated a volume of tissue to ablate, control unit 112 may calculate an ablation plan. An ablation plan may be a surgical plan for how to use system 100, and specifically catheter device 101, to ablate the treatment zone by specifying specific electrodes 103 of catheter device 101 to activate and specific amounts of electrical energy to be applied to each electrode once distal portion 102 is positioned proximate to or at the treatment zone. For example, the ablation plan may involve multiple overlapping ablations of varied shapes, depths and lengths. In some examples, the ablation plan aims to encompass all of the treatment zone while minimizing the amount of ablated healthy tissue. For example, the ablation plan may include instructions to activate a specific group of electrodes 103 in order to create a shaped ablation zone that targets unhealthy tissue of the treatment zone. In some examples, the ablation plan may include specific instructions for motor assembly 108 in order to position distal portion 102 at the treatment zone using motor assembly 108. The ablation plan may include instructions for the robot computer controller 114 to execute in order to position distal portion 102 of catheter device 101 at the treatment zone. In some examples, the user may confirm the ablation plan and may make adjustments to the ablation plan, as necessary, via the GUI.
When executing an ablation plan, the user may position distal portion 102 proximate to and/or at the selected treatment zone. For example, the user may align active portions, or portions at which electrodes 103 are positioned, of distal portion 102 with the treatment zone. The user may monitor the positioning of distal portion 102 using scanner 106, and may visualize via display 116 the positioning of distal portion 102 within the patient's body. In some examples, the control unit 112 may create and store a reference point, calculated using images generated by scanner 106, of the position of distal portion 102 at the treatment zone. The reference point, or reference position, may be an initial condition and/or an initial position of distal portion 102 created using an initial image from an initial scan of the treatment zone. In some examples, the reference point or reference position may be a starting position for a user to identify before treating the selected treatment zone. The reference point may be used by control unit 112 to calculate required movements of distal portion 102 relative to the treatment zone.
Once a reference point has been established and stored in control unit 112, control unit 112 may move catheter device 101 using motor assembly 108 to a starting point of treatment in accordance with the ablation plan outlined earlier. In some examples, control unit 112 may send instructions to motor assembly 108 to move catheter device 101 automatically, e.g. without human mechanical input from a proximal handle. Once the catheter device 101, and specifically distal portion 102, is positioned at the starting point, control unit 112 may activate power generator 110 and supply a specific group of electrodes 103 with energy at a predetermined power and voltage limit setting. By supplying the specifically selected electrodes 103 with the predetermined amount of energy, system 100 may create a shaped ablation similar to the planned shaped ablation established in the ablation plan. In some examples, control unit 112 may measure the real-time impedance feedback from each of the electrodes 103 and may actively adjust the energy supplied to each of the electrodes 103 based on the measured impedance feedback. In some examples, distal portion 102 of catheter device 101 may be moved after an initial shaped ablation is applied to the treatment zone, and then control unit 112 may supply a different, specifically selected group of electrodes 103 with a predetermined amount of energy. This process may be repeated until the entire treatment zone has been ablated. In some examples, control unit 112 may automatically calculate a new ablation plan based on measured impedance feedback from each of electrodes 103.
After ablation using catheter device 101, the user may then acquire CT or other medical images using scanner 106, and may compare the newly acquired images to the images used to create the ablation plan. The images showing the targeted tissue (such as diseased tissue) and the images showing the ablated tissue may then be registered to one another and compared to quantify the extent of ablation treatment, and confirm that all of the required tissue has been ablated. If portions of target tissue remain, the user may then create a new ablation plan to ablate the remaining tissue.
A proximal end of internal element 460 may be configured to couple to control unit 112 and may include an electrically conductive material to transfer electrical energy from control unit 112 to distal protrusion 462 of internal element 460. When the radially-outermost surface 463 of distal protrusion 462 contacts one or more electrodes 403, internal element 460 may transfer electrical energy supplied by control unit 112 to those one or more electrodes 403. For example, distal protrusion 462 may form an electrical connection with one or more electrodes 403 when distal protrusion comes into contact with an inner surface of the one or more electrodes 403. Internal element 460 may be moved proximally or distally and rotated about its longitudinal axis to locate specific electrodes 403 for electrical activation. In some examples, internal element 460 may continually translate proximally and/or distally and/or rotate at a specific frequency to create a user desired ablation pattern. In some examples (not shown), a catheter device may include an internal element (similar to internal element 460) with a plurality of protrusions (similar to protrusion 462) that may contact a plurality of electrodes simultaneously, and in some examples a catheter device may include a plurality of internal elements (similar to internal element 460) that may contact a plurality of electrodes simultaneously.
Catheter device 401 may operate in substantially the same manner as catheter device 101 described hereinabove. In some examples, a proximal portion of internal element 460 may be coupled to a motor assembly separate from a motor assembly used to control the position of distal portion 402 and proximal elongate 405. By activating each electrode 403 using internal element 460, catheter device 401 may not require additional wiring from each electrode 403 and may facilitate manufacturing and miniaturization of catheter device 401.
By providing a catheter device that a user may selectively ablate tissue and specifically regulate power applied to a plurality of electrodes positioned at a treatment zone, a user may reduce injury of healthy tissue and avoid unnecessary harm to a patient's body caused by the excessive ablation of tissue during a radiofrequency ablation procedure.
It will be apparent to those skilled in the art that various modifications and variations may be made in 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.
This application claims the benefit of priority from U.S. Provisional Application No. 62/930,721, filed Nov. 5, 2019, which is incorporated by reference herein in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/058852 | 11/4/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62930721 | Nov 2019 | US |
