Irreversible electroporation (IRE) balloon catheter with membrane-insulated high-voltage balloon wire

Abstract

To provide a balloon catheter for irreversible electroporation.SOLUTION: A medical probe includes a shaft and an expandable balloon. The shaft is configured for insertion into an organ of a patient. The expandable balloon is coupled to a distal end 22a of the shaft, and includes (a) an expandable membrane 44 having an outer surface and an inner surface, where the expandable membrane is configured to be expanded from a collapsed shape to a balloon shaped member, (b) a plurality of electrodes 55 disposed on the outer surface of the expandable membrane, (c) one or more wires 60 connected to the plurality of electrodes, the wires extending from the distal end to the electrodes, (d) and an expandable cover 50 that encapsulates the wires between the expandable cover and the expandable membrane so that the wires are constrained between the cover and the expandable membrane but the electrodes are exposed to the ambient environment.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates generally to invasive medical probes, and more particularly to balloon catheters for irreversible electroporation. [Background technology]

[0002] The delivery of irreversible electroporation (IRE) energy to tissue has previously been proposed in the patent literature. For example, U.S. Patent Application Publication No. 2019 / 0030328 describes a medical device configured to electroporate a region of tissue, the medical device including a balloon having a distal portion and a proximal portion, and a plurality of electrodes disposed on the distal portion of the balloon, each of the plurality of electrodes configured to deliver electroporation energy to the region of tissue.

[0003] As another example, U.S. Patent No. 10,285,755 describes a catheter having a distal expandable element coupled to a catheter body with a mesh or array of longitudinal splines that substantially surround the expandable element, at least a portion of the mesh or splines being electrically conductive. In one embodiment, an electrically insulated portion is disposed between two conductive portions of the mesh. The conductive portions can be operated in a bipolar manner to conduct electrical current through tissue, around the insulating portion, along a path substantially parallel to the longitudinal axis of the expandable element between adjacent or otherwise spaced conductive portions of the mesh.

[0004] PCT Publication WO 2019 / 055512 describes systems, devices, and methods for electroporation ablation therapy, including an endocardial ablation device including an expandable member, such as a balloon, and at least one electrode for focal ablation by pulse delivery to tissue. In one embodiment, the ablation device includes a set of electrodes disposed on the balloon. The electrodes may be formed on the surface of the distal end of the balloon and may be useful for forming lesions on the endocardial surface via focal ablation. During use, the electrodes may be disposed within a ventricle to deliver a pulse waveform to ablate tissue. Each electrode may be coupled to a corresponding insulated electrical lead, each lead having sufficient electrical insulation to maintain a potential difference across its thickness without dielectric breakdown. Summary of the Invention [Means for solving the problem]

[0005] One embodiment of the present invention provides a medical probe including a shaft and an expandable balloon. The shaft is configured for insertion into a patient's organ. The expandable balloon is coupled to a distal end of the shaft, the expandable balloon including: (a) an expandable membrane having an outer surface and an inner surface, the expandable membrane configured to be expanded from a collapsed configuration into a balloon-shaped member; (b) a plurality of electrodes disposed on the outer surface of the expandable membrane; (c) one or more wires connected to the plurality of electrodes, the wires extending from the distal end to the electrodes; and (d) an expandable cover that encapsulates the wires between the expandable cover and the expandable membrane such that the wires are constrained between the cover and the expandable membrane but the electrodes are exposed to the surrounding environment.

[0006] In some exemplary embodiments, the medical probe further includes a seal configured to extend over a distal edge of the cover membrane and seal the cover to the expandable membrane, hi other exemplary embodiments, the seal covers a proximal edge of each of the electrodes.

[0007] In some embodiments, the electrodes are disposed conformally about the longitudinal axis of the expandable membrane, hi another exemplary embodiment, each of the electrodes is coupled to the outer surface of the expandable membrane via a substrate.

[0008] In some exemplary embodiments, at least one of the electrodes includes a radiopaque marker that has a different configuration than other radiopaque markers on the other electrodes.

[0009] In some exemplary embodiments, the plurality of electrodes are disposed on a distal hemispherical portion of an expandable membrane.

[0010] According to an exemplary embodiment of the present invention, there is also provided a method of manufacturing a medical probe, the method including assembling an expandable balloon by assembling an expandable membrane having an outer surface and an inner surface, the expandable membrane configured to expand from a collapsed configuration into a balloon-shaped member. A plurality of electrodes are disposed on the outer surface of the expandable membrane. Wires are connected to the plurality of electrodes, and an expandable cover is used to encapsulate the wires between the cover and the expandable membrane such that the wires are constrained between the cover and the expandable membrane but the electrodes are exposed to the surrounding environment. The inflatable balloon is coupled to a distal end of a shaft.

[0011] In some exemplary embodiments, the method further includes sealing the cover to the expandable membrane using a seal extending over a distal edge of the cover. [Brief explanation of the drawings]

[0012] The present invention will be more fully understood from the following detailed description taken in conjunction with the drawings, in which: [Figure 1] FIG. 1 is a schematic, pictorial illustration of a catheter-based irreversible electroporation (IRE) system, in accordance with an exemplary embodiment of the present invention. [Figure 2] 2 is an exploded perspective view of the irreversible electroporation (IRE) balloon catheter of FIG. 1 in accordance with an exemplary embodiment of the present invention. FIG. [Figure 3] FIG. 3 is a side view of the irreversible electroporation (IRE) balloon catheter of FIG. 2, in accordance with an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Overview Irreversible electroporation (IRE), used as an invasive treatment, kills tissue cells by subjecting the tissue to a high-voltage pulse. Medical probes, such as balloon catheters, can be used to apply high-voltage pulses to tissue using multiple electrodes disposed on a balloon. For wires used to conduct high-voltage electrical signals to electrodes on the balloon, exposing the wires to the surrounding biological tissue environment (e.g., biological tissue or blood) as well as the interior of the balloon can be detrimental. Therefore, the wiring to the balloon electrodes must be sufficiently electrically insulated to prevent dielectric breakdown.

[0014] An exemplary embodiment of the present invention provides an IRE balloon catheter that includes an insulated wire. However, while the wire has its own insulation, this insulation may not be sufficient in environments with high water content. Therefore, the wire is disposed on the outer surface of the balloon catheter's expandable membrane, so that the wire is sufficiently isolated from, for example, the conductive saline solution typically used to inflate the expandable membrane.

[0015] To achieve sufficient electrical insulation from the surrounding environment, such as blood, which is also conductive, the wire is disposed between an expandable membrane and an enclosing cover membrane, and the two membranes are attached to each other in such a way that the wire is trapped between the two membranes and only the electrode connected to the wire is exposed to the surrounding environment.

[0016] The disclosed IRE balloon catheter is coupled to the distal end of a hollow shaft for insertion into a patient's organ. An expandable membrane is disposed about the longitudinal axis of the distal end of the shaft and coupled to an elongated rod at its distal end. When pulled proximally into the hollow shaft, the elongated rod expands the expandable membrane from an elongated, collapsed shape into a balloon-shaped member.

[0017] Each of the multiple electrodes is connected to the output of the IRE pulse generator via one or more of the aforementioned wires disposed between the two membranes, and these highly insulated wires are joined at the proximal end of the balloon catheter to provide a wire extending inside the hollow shaft.

[0018] In some exemplary embodiments, the cover membrane is sealed to the expandable membrane using a seal extending over the distal edge of the cover membrane. Additionally or alternatively, the cover membrane is adhered to the outer surface of the expandable membrane, for example, by adhering the cover membrane to the outer surface of the expandable membrane over its entire area.

[0019] The IRE balloon catheter is also configured with the following features, which may be combined in various combinations or permutations: for example, each of a plurality of electrodes defines a shape optimized for IRE, each electrode is disposed on the outer surface of the expandable membrane via a substrate, each electrode includes a radiopaque marker having a different configuration than other radiopaque markers on the other electrodes, the expandable membrane includes a generally spherical member, and the expandable cover membrane includes a hemispherical member.

[0020] The disclosed IRE balloon catheters allow for the application of IRE therapy in an electrically safe manner and may therefore improve the clinical outcomes of invasive IRE therapy, such as IRE treatment of cardiac arrhythmias.

[0021] System Description 1 is a schematic, pictorial illustration of a catheter-based irreversible electroporation (IRE) system 20, in accordance with an exemplary embodiment of the present invention. System 20 includes a catheter 21, the shaft 22 of which is inserted through a sheath 23 into a heart 26 of a patient 28. The proximal end of catheter 21 is connected to a console 24.

[0022] Console 24 includes an IRE generator 38 for applying IRE pulses via catheter 21 to irreversibly electroporate pulmonary vein ostial tissue within left atrium 45 of heart 26. In the exemplary embodiments described herein, catheter 21 may be used for any other suitable therapeutic and / or diagnostic purposes, such as electrically sensing and / or irreversibly electroporating other tissue within heart 26.

[0023] Physician 30 inserts catheter 22 through the vascular system of patient 28. As seen in inset 25, an expandable balloon catheter 40 attached to distal end 22a of shaft 22 includes a hemispherical high-voltage insulating cover membrane 50, which is shown in detail in FIG. 2. During insertion of shaft 22, balloon 40 is maintained in a folded configuration inside sheath 23. By containing balloon 40 in a folded configuration, sheath 23 also serves to minimize vascular trauma along the path to the target location. Physician 30 navigates the distal end of shaft 22 to the target location within heart 26.

[0024] Once the distal end 22a of the shaft 22 reaches the target location, the physician 30 retracts the sheath 23 and expands the balloon 40, among other things, by pumping saline into the interior volume defined by the aforementioned expandable membrane. The physician 30 then manipulates the shaft 22 to engage an electrode 55 disposed on the balloon catheter 40 with the inner wall of the ostium and operates the console 24 to apply a high-voltage IRE pulse to the ostial tissue via the electrode 55.

[0025] Console 24 includes a processor 41, typically a general-purpose computer, with suitable front-end and interface circuitry 37 for receiving signals from catheter 21 and external electrodes 49, which are typically positioned around the chest of patient 26. To this end, processor 41 is connected to external electrodes 49 by wires running through cable 39.

[0026] The processor 41 is typically programmed (software) to perform the functions described herein. The software may be downloaded to the computer in electronic form, for example over a network, or alternatively or additionally may be provided and / or stored on a non-transitory tangible medium, such as magnetic, optical, or electronic memory.

[0027] Although the illustrated exemplary embodiment relates specifically to the use of a balloon for IRE of cardiac tissue, the elements and methods of system 20 described herein may alternatively be applied to controlling ablation using other types of multi-electrode ablation devices, such as multi-arm ablation catheters.

[0028] IRE balloon catheter with membrane-insulated high-voltage balloon wire FIG. 2 is an exploded perspective view of the irreversible electroporation (IRE) balloon catheter 40 of FIG. 1, in accordance with an exemplary embodiment of the present invention.

[0029] The expandable membrane 44 of the balloon catheter 40 is attached to the distal end 22a of the shaft 22 at a proximal membrane portion 46 of the membrane 44. The membrane 44 is disposed about the longitudinal axis 42 and has an outer surface 44a and an inner surface 44b. The outer surface 44a is exposed to the surrounding environment, while the inner surface 44b is exposed to the interior volume of the balloon defined by the membrane 44.

[0030] The expandable membrane 44 is configured to expand from a collapsed shape (a generally elongated tubular configuration) to a balloon (or generally spherical) shaped member. A plurality of electrodes 55 are disposed on the outer surface 44a of the expandable membrane 44. The electrodes 55 are equidistantly spaced on a distal hemispherical portion of the membrane 44. In the illustrated exemplary embodiment, each of the electrodes 55 is connected to an insulated wire 60 electrically connected to conduct high voltage to the electrode. Each wire 60 includes a conductive core surrounded by an electrically insulating sleeve. The wires 60 are coupled to the output of the IRE generator 24 by wiring (not shown) that extends through the hollow shaft 22 to the console 24.

[0031] The underside of each electrode 55 is an electrode surface that is not exposed to the ambient environment and is typically bonded to the outer surface 44 a of the membrane 44 .

[0032] Expandable cover membrane 50, having boundary 52, encapsulates wire 60 between cover membrane 50 and expandable membrane 44 such that wire 60 is constrained between membrane 44 and cover membrane 50. For brevity and to avoid confusion with membrane 44, expandable cover membrane 50 is also referred to herein simply as the "cover," "cover membrane," or "expandable cover." In this manner, wire 60 is resilient to dielectric breakdown due to the high-voltage electrical signals conducted during an IRE procedure. In other words, the total electrical insulation between the core of wire 60 and the surrounding environment includes both the insulation of the insulating sleeve of wire 60 and the insulation of cover membrane 50. In an exemplary embodiment, cover membrane 50 is secured to the expandable balloon with an adhesive (not shown).

[0033] 3 is a side view of the irreversible electroporation (IRE) balloon catheter 40 of FIG. 2, in accordance with an exemplary embodiment of the present invention. As can be seen, each of the plurality of electrodes 55 defines an area that is not covered by the expandable cover membrane 50 to allow the electrode to be exposed to the surrounding environment.

[0034] The electrodes 55 are equiangularly arranged about the longitudinal axis 42 such that the cover membrane 50 encapsulates the proximal edge of each electrode 55. The seal 54 may extend over the boundary 52 of the cover membrane 50 (i.e., the proximal edge of the electrode 55) and extend up to several millimeters over the proximal portion of the outer surface of the electrode 55 while still allowing the electrode to be exposed to the ambient environment. In one embodiment, the seal 54 may be provided in the form of a polyurethane or epoxy seal.

[0035] Typically, each electrode 55 is coupled to the outer surface of the expandable membrane 44 via a substrate 53 that is itself connected or bonded to the outer surface of the membrane 44 .

[0036] As can be seen in FIG. 3, each wire 60 on membrane 44 extends from distal end 22 a to a corresponding electrode 55 such that each wire follows the topographic outer surface of membrane 44 .

[0037] Because each wire 60 may be used to conduct high-voltage electrical signals, exposing the wires 44 to the surrounding biological environment (e.g., biological tissue or blood) would be detrimental. Although each wire 60 has its own insulating sleeve, this insulation may not be sufficient in a high-humidity environment, especially considering the high voltages involved. In this manner, the expandable cover membrane 50 eliminates potential electrical breakdown between the wires and the surrounding environment. The electrodes remain exposed to biological tissue so that they can perform their intended purpose. Furthermore, because the wires 60 are constrained or captured between the two membranes, there is little chance of the wires becoming tangled or accidentally being connected to the wrong electrode during assembly.

[0038] The outer walls of membranes 44 and 50 are typically made of a biocompatible material formed from a plastic (e.g., a polymer), such as polyethylene terephthalate (PET), polyurethane, or PEBAX®, which provides sufficient electrical insulation against breakdown under the strong electric fields generated by the IRE pulse.

[0039] Any of the examples or exemplary embodiments described herein may include various other features in addition to or instead of those described above. In particular, the exemplary configurations shown in Figures 2 and 3 have been selected for conceptual clarity only. For example, the cover membrane 50 may have its inner surface adhered to the outer surface of the expandable membrane 44.

[0040] Although the exemplary embodiments described herein relate primarily to IRE procedures, the disclosed technology may also be used in other suitable applications, such as electrophysiological (EP) sensing. Examples of EP catheters are described, for example, in U.S. Provisional Patent Application No. 62 / 769,424, filed November 19, 2018, which is assigned to the assignee of the present patent application and the disclosure of which is incorporated herein by reference.

[0041] Although the exemplary embodiments described herein relate primarily to cardiac applications, the methods and systems described herein may also be used in other medical applications, such as neurology, ENT, and general surgical procedures.

[0042] Accordingly, it will be understood that the above-described embodiments are cited by way of example, and that the present invention is not limited to what has been particularly shown and described above. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described in the foregoing specification, as well as variations and modifications thereof not disclosed in the prior art that would occur to one skilled in the art upon reading the foregoing description. Documents incorporated by reference into this patent application shall be deemed an integral part of this application, except that to the extent that any term is defined in these incorporated documents in a manner that is inconsistent with a definition expressly or impliedly made herein, only the definition in this specification shall be considered.

[0043] [Embodiment] (1) A medical probe for irreversible electroporation, the medical probe comprising: a shaft for insertion into a patient's organ; an expandable balloon coupled to a distal end of the shaft, the expandable balloon comprising: an expandable membrane having an outer surface and an inner surface, the expandable membrane configured to be expanded from a collapsed configuration into a balloon-shaped member; a plurality of electrodes disposed on the outer surface of the expandable membrane; one or more wires connected to the plurality of electrodes, the wires extending from the distal end to the electrodes; an expandable balloon including an expandable covering that encapsulates the wire between the expandable covering and the expandable membrane such that the wire is constrained between the cover and the expandable membrane but the electrode is exposed to the surrounding environment. (2) A medical probe as described in embodiment 1, further comprising a sealing portion extending over the distal edge of the cover membrane and configured to seal the cover to the expandable membrane. (3) A medical probe as described in embodiment 2, wherein the sealing portion covers the proximal edge of each of the electrodes. (4) A medical probe as described in embodiment 1, wherein the electrodes are arranged equiangularly about the longitudinal axis of the expandable membrane. (5) A medical probe as described in embodiment 1, wherein each of the electrodes is coupled to the outer surface of the expandable membrane via a substrate.

[0044] (6) A medical probe as described in embodiment 1, wherein at least one of the electrodes includes a radiopaque marker having a configuration different from other radiopaque markers on the other electrodes. (7) A medical probe as described in embodiment 1, wherein the plurality of electrodes are disposed on a distal hemispherical portion of the expandable membrane. (8) A method for manufacturing a medical probe for irreversible electroporation, said method comprising: Assembling an expandable balloon, assembling an expandable membrane having an outer surface and an inner surface, the expandable membrane configured to be expanded from a collapsed configuration into a balloon-shaped member; disposing a plurality of electrodes on the outer surface of the expandable membrane; connecting wires to the plurality of electrodes; assembling by using an expandable cover to encapsulate the wires between the cover and the expandable membrane such that the wires are constrained between the cover and the expandable membrane but the electrodes are exposed to the ambient environment; and coupling the expandable balloon to a distal end of a shaft. (9) The method of claim 8, further comprising sealing the cover to the expandable membrane using a seal extending over a distal edge of the cover. (10) A medical probe for irreversible electroporation, the medical probe comprising: a shaft for insertion into a patient's organ; an expandable balloon coupled to a distal end of the shaft, the expandable balloon comprising: an expandable membrane having an outer surface and an inner surface, the expandable membrane configured to be expanded from a collapsed configuration to a spherical balloon shape; a plurality of electrodes disposed on the outer surface of the expandable membrane; one or more wires connected to the plurality of electrodes, the wires extending from the distal end to the electrodes; an expandable cover having a hemispherical shape that covers a proximal hemisphere of the expandable membrane when the expandable membrane is expanded into the spherical balloon shape, the expandable cover enclosing the wire between the expandable cover and the expandable membrane such that the wire is constrained between the cover and the expandable membrane but the electrode is exposed to the surrounding environment; and an expandable balloon.

[0045] (11) The medical probe of claim 10, further comprising a seal portion extending over a distal edge of the cover membrane and configured to seal the cover to the expandable membrane. (12) A medical probe according to claim 11, wherein the sealing portion covers the proximal edge of each of the electrodes. (13) The medical probe of claim 10, wherein the electrodes are equiangularly arranged about the longitudinal axis of the expandable membrane. (14) The medical probe of claim 10, wherein each of the electrodes is coupled to the outer surface of the expandable membrane via a substrate. (15) The medical probe of claim 10, wherein at least one of the electrodes includes a radiopaque marker having a different configuration than other radiopaque markers on the other electrodes.

[0046] (16) The medical probe according to claim 10, wherein the plurality of electrodes are disposed on a distal hemispherical portion of the expandable membrane. (17) A method for manufacturing a medical probe for irreversible electroporation, the method comprising: Assembling an expandable balloon, assembling an expandable membrane having an outer surface and an inner surface, the expandable membrane configured to be expanded from a collapsed configuration to a spherical balloon shape; disposing a plurality of electrodes on the outer surface of the expandable membrane; connecting wires to the plurality of electrodes; assembling by using an expandable cover having a hemispherical shape that covers a proximal hemisphere of the expandable membrane when the expandable membrane is expanded into the spherical balloon shape, encapsulating the wire between the cover and the expandable membrane such that the wire is constrained between the cover and the expandable membrane but the electrode is exposed to the surrounding environment; and coupling the expandable balloon to a distal end of a shaft. (18) The method of claim 17, further comprising sealing the cover to the expandable membrane using a seal extending over a distal edge of the cover.

Claims

1. 1. A medical probe for irreversible electroporation, said medical probe comprising: a shaft for insertion into a patient's organ; an expandable balloon coupled to a distal end of the shaft, the expandable balloon comprising: an expandable membrane having an outer surface and an inner surface, the expandable membrane configured to be expanded from a collapsed configuration to a spherical balloon shape; a plurality of electrodes disposed on the outer surface of the expandable membrane; one or more wires connected to the plurality of electrodes, the wires extending from the distal end to the electrodes; an expandable cover having a hemispherical shape that covers a proximal hemisphere of the expandable membrane when the expandable membrane is expanded into the spherical balloon shape, the expandable cover encapsulating the wire between the expandable cover and the expandable membrane such that the wire is constrained between the expandable cover and the expandable membrane but at least a portion of the electrode is exposed to the surrounding environment; a distal edge of the expandable cover having an annular shape that extends around the circumference of the expandable balloon and overlaps only a proximal portion of each of the plurality of electrodes; the medical probe further comprising a seal positioned along the distal edge of the expandable cover and configured to seal the expandable cover to the expandable membrane; A medical probe, wherein the sealing portion covers only the proximal portion of each of the plurality of electrodes.

2. The medical probe of claim 1 , wherein the electrodes are equiangularly disposed about a longitudinal axis of the expandable membrane.

3. The medical probe of claim 1 , wherein each of the electrodes is coupled to the outer surface of the expandable membrane via a substrate.

4. The medical probe of claim 1 , wherein at least one of the electrodes includes a radiopaque marker having a different configuration than other radiopaque markers on other electrodes.

5. The medical probe of claim 1 , wherein the plurality of electrodes are disposed on a distal hemispherical portion of the expandable membrane.

6. 1. A method for manufacturing a medical probe for irreversible electroporation, said method comprising: Assembling an expandable balloon, assembling an expandable membrane having an outer surface and an inner surface, the expandable membrane configured to be expanded from a collapsed configuration to a spherical balloon shape; disposing a plurality of electrodes on the outer surface of the expandable membrane; connecting wires to the plurality of electrodes; assembling by using an expandable cover having a hemispherical shape that covers a proximal hemisphere of the expandable membrane when the expandable membrane is expanded into the spherical balloon shape, and encapsulating the wire between the expandable cover and the expandable membrane such that the wire is constrained between the expandable cover and the expandable membrane but at least a portion of the electrode is exposed to the surrounding environment; and coupling the expandable balloon to a distal end of a shaft; a distal edge of the expandable cover having an annular shape that extends around the circumference of the expandable balloon and overlaps only a proximal portion of each of the plurality of electrodes; the medical probe further comprising a seal positioned along the distal edge of the expandable cover and configured to seal the expandable cover to the expandable membrane; The method of manufacturing, wherein the sealing portion covers only the proximal portion of each of the plurality of electrodes.

7. The method of claim 6 , further comprising sealing the expandable covering to the expandable membrane using the seal positioned along the distal edge of the expandable covering.

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