Medical probes containing a roughly hemispherical or semiconical membrane
The medical probe with a flexible end effector and IRE energy delivery system addresses thermal risks and anatomical challenges, enhancing cardiac ablation efficacy and reducing procedure complexity.
Patent Information
- Application Number
- JP2025283777
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-12-31
- Filing Date
- 2025-12-26
- Publication Date
- 2026-07-13
AI Technical Summary
Current ablation technologies for cardiac arrhythmias face challenges such as thermal risks, difficulty in reaching complex anatomical shapes, and reliance on physician skill, leading to incomplete tissue isolation and prolonged procedure times.
A medical probe with an end effector featuring radially extending spines and a membrane, incorporating flexible circuits and electrode pairs, allows for non-thermal irreversible electroporation (IRE) energy delivery with improved tissue contact and mapping capabilities.
Enhances the effectiveness of cardiac ablation by reducing thermal risks, improving tissue contact, and simplifying the procedure through enhanced electrode flexibility and precise energy delivery, thereby reducing procedure time and complication risks.
Smart Images

Figure 2026116840000001_ABST
Abstract
Description
Technical Field
[0001] This technology generally relates to medical devices, particularly medical probes having electrodes, and more particularly to medical probes suitable for use in tissue mapping and ablation, but is not limited thereto.
Background Art
[0002] Cardiac arrhythmias such as atrial fibrillation (AF) occur when regions of cardiac tissue conduct electrical signals abnormally to adjacent tissue. This disrupts the normal cardiac cycle and causes an asynchronous rhythm. Certain procedures that exist for treating arrhythmias include surgically destroying the source of the signals causing the arrhythmia and destroying the conduction pathways of such signals. By applying energy via a catheter to selectively ablate cardiac tissue, it is sometimes possible to stop or alter the propagation of unwanted electrical signals from one part of the heart to another.
[0003] Many current ablation approaches in the art utilize radiofrequency (RF) electrical energy to heat tissue. RF ablation can have certain risks associated with thermal heating that can lead to tissue charring, burning, steam popping, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistula.
[0004] Cryoablation is an alternative approach to RF ablation that generally reduces the thermal risks associated with RF ablation. However, operating a cryoablation device and selectively applying cryoablation is generally more difficult compared to RF ablation, and thus cryoablation is not feasible for certain anatomical shapes that can be reached by an electrical ablation device.
[0005] Several ablation approaches utilize irreversible electroporation (IRE) to ablate cardiac tissue using non-thermal ablation methods. IRE delivers short pulses of high voltage to the tissue, causing irreversible permeabilization of the cell membrane. Delivery of IRE energy to tissue using multi-electrode probes has been previously proposed in the patent literature. Examples of systems and devices configured for IRE ablation are described in U.S. Patent Applications Publications 2021 / 0169550(A1), 2021 / 0169567(A1), 2021 / 0169568(A1), 2021 / 0196372(A1), 2021 / 0177503(A1), and 2021 / 0186604(A1), and U.S. Patent No. 11,540,877, each of which is incorporated herein in whole by reference and attached to the appendices herein.
[0006] Areas of cardiac tissue can be mapped by catheters to identify abnormal electrical signals. Some catheter ablation procedures, particularly those involving persistent atrial fibrillation, may be performed using electrophysiological (EP) mapping to targeted areas of abnormal electrical signals. Such EP mapping may involve the use of diagnostic electrodes configured to monitor electrical signals within the cardiovascular system to precisely indicate the location of abnormal conductive tissue sites involved in arrhythmias. An example of an EP mapping system is described in U.S. Patent No. 5,738,096, which is incorporated herein by reference in its entirety. Examples of EP mapping catheters are described in U.S. Patent No. 9,907,480, U.S. Patent Publication No. 2018 / 0036078, and U.S. Patent Publication No. 2018 / 0056038, each of which is incorporated herein by reference in its entirety.
[0007] In addition to using EP mapping, some catheter ablation procedures can be performed using image-guided surgery (IGS) systems. IGS systems can allow physicians to visually track the catheter's position within the patient in real time in relation to images of the patient's anatomical structures. Some systems, including the CARTO3® system by Biosense Webster, Inc. (Irvine, California), can offer a combination of EP mapping and IGS capabilities. In current practice, the effectiveness of IRE energy delivery depends on the physician's skill, which means that patients may suffer from incomplete isolation of the target area. To effectively deliver IRE energy and perform ablation, ablation catheters typically need to be reoriented multiple times during the procedure, which increases the procedure time and complicates the ablation process. Furthermore, existing catheters generally require rigid internal structural members to ensure that the given configuration is maintained. Rigidity is disadvantageous during manipulation within body organs, as it can prevent electrodes from contacting tissue. Other catheters may include flexible end-effectors designed to overcome this disadvantage. These catheters may contain layered components, which can be time-consuming, complex, and expensive to manufacture and assemble. [Overview of the project] [Problems that the invention aims to solve]
[0008] Therefore, there is a need for improved end-effectors in medical probes that can address these issues, including ablation and mapping. [Means for solving the problem]
[0009] According to the technology of the present disclosure, an end effector for a medical probe, the end effector comprising a plurality of spines extending radially outward from the longitudinal axis of the end effector in an extended configuration, and a membrane connected to the plurality of spines, the membrane comprising a distal end that defines a volume surrounding the longitudinal axis and having an open end, the membrane comprising a first surface and a second surface opposite to the first surface, and a first flexible circuit disposed on the first surface of the membrane in close proximity to each of the plurality of spines and extending around the longitudinal axis, and in close proximity to each of the plurality of spines An end effector is provided, comprising: a second flexible circuit disposed on a second surface of a film and extending around a longitudinal axis; a plurality of first electrode pairs disposed on the first flexible circuit relative to each other and proximal to spines among a plurality of spines; and a plurality of second electrode pairs disposed on the second flexible circuit relative to each other and proximal to spines among a plurality of spines, such that the first electrode pairs and the second electrode pairs define a mirror image configuration together with the film between the first electrode pairs and the second electrode pairs.
[0010] The present invention relates to a medical probe comprising an elongated probe body and an end effector connected to the distal end of the elongated probe body, wherein the elongated probe body and the end effector extend along a longitudinal axis, and the end effector is connected to the elongated probe body and comprises a plurality of spines extending radially outward from the longitudinal axis of the end effector in an extended configuration, and a membrane connected to the plurality of spines, wherein the membrane comprises a distal end that surrounds the longitudinal axis and defines a volume having an open end, and the membrane comprises a first surface and a second surface opposite to the first surface, and a first flexible circuit disposed on the first surface of the membrane in proximity to each of the plurality of spines and extending around the longitudinal axis, and the second surface of the membrane in proximity to each of the plurality of spines A medical system is further provided, comprising: a medical probe comprising: a second flexible circuit arranged on a surface and extending around a longitudinal axis; a plurality of first ablation electrode pairs arranged on the first flexible circuit and located proximal to each other and to spines among a plurality of spines; a plurality of second electrode pairs, the second electrode pairs arranged on the second flexible circuit and proximal to each other and to spines among a plurality of spines, such that the first electrode pairs and the second electrode pairs have a film between them, defining a mirror image configuration; and an ablation generator configured to provide ablation pulses to the plurality of first electrode pairs and the plurality of second electrode pairs.
[0011] The present disclosure provides a method for manufacturing an end effector for a medical probe, the method comprising: forming a plurality of spines extending away from the longitudinal axis; arranging a first flexible circuit on a first side of the plurality of spines, the first flexible circuit comprising a first flexible substrate and a first electrode pair; arranging a second flexible circuit on a second side of the plurality of spines, the second flexible circuit comprising a second flexible substrate and a second electrode pair; arranging a first insulating material sheet in contact with the first flexible circuit, the first sheet surrounding the longitudinal axis; arranging a second insulating material sheet in contact with the second flexible circuit, the second sheet surrounding the longitudinal axis and defining a volume having an open end; and molding the first sheet and the second sheet to enclose the first flexible circuit and the second flexible circuit. [Brief explanation of the drawing]
[0012] [Figure 1] This is a schematic diagram of a medical system including a medical device, which includes a medical probe having a distal tip equipped with an electrode, according to the disclosed technology. [Figure 2A] This is a schematic diagram showing a distal perspective view of the distal tip of a medical probe in an extended configuration according to the technology of this disclosure. [Figure 2B] This schematic diagram shows a distal perspective view of an alternative configuration for the distal tip of a medical probe in an extended configuration, according to the technology of this disclosure. [Figure 3] This is a schematic diagram showing a perspective view of the proximal side of the distal tip of the medical probe in the extended configuration according to the technology of this disclosure. [Figure 4A] This is a schematic diagram showing a cross-sectional view of the distal tip along line 4A-4A in Figure 2A, according to the technology of this disclosure. [Figure 4B] This is a schematic diagram showing a cross-sectional view similar to the cross-sectional view in Figure 4A of an alternative configuration for the distal tip portion of Figure 2B, based on the technology disclosed herein. [Figure 5A] This is a schematic diagram showing a detailed view of detail A in Figure 4A, illustrating an exemplary ablation configuration of an electrode according to the technology of this disclosure. [Figure 5B] This schematic diagram shows a detailed view similar to Figure 5A, illustrating an alternative ablation configuration for electrodes using the technology disclosed herein. [Figure 5C] This schematic diagram shows a detailed view similar to Figure 5A, illustrating an alternative ablation configuration for electrodes using the technology disclosed herein. [Figure 6] This schematic diagram shows a similar detailed view to Figure 5A illustrating an alternative electrode configuration according to the technology of this disclosure. [Figure 7] This schematic diagram shows a similar detailed view to Figure 5A illustrating an alternative film configuration using the technology of this disclosure. [Figure 8] This schematic diagram shows a similar detailed view to Figure 5A illustrating an alternative film configuration using the technology of this disclosure. [Figure 9] This is a schematic diagram showing a distal perspective view of another distal tip in an extended configuration according to the technology of this disclosure. [Figure 10] This is a schematic diagram showing another cross-sectional view of the distal tip along line 10-10 in Figure 9, according to the technology of the present disclosure. [Figure 11] This is a schematic drawing showing a distal perspective view of another exemplary distal tip in an extended configuration according to the technology of the present disclosure. [Figure 12] This is a schematic diagram showing a side view of the distal tip portion of Figure 11, which is positioned within the technical sheath of the present disclosure. [Figure 13] This is a flowchart illustrating a method for manufacturing the distal tip of a medical probe using the technology disclosed herein. [Figure 14] This is a schematic diagram showing a first exemplary electrode configuration of an exemplary end effector according to the technology of the present disclosure, which includes an elongated ablation electrode and a diagnostic electrode positioned along the ablation electrode. [Figure 15]A schematic drawing showing a second exemplary electrode configuration of an exemplary end effector that includes an elongated ablation electrode segmented into small parallel stripes and a diagnostic electrode disposed along the ablation electrode, according to the techniques of the present disclosure. [Figure 16] A schematic drawing showing a third exemplary electrode configuration for an exemplary end effector that includes a rectangular elongated ablation electrode without a diagnostic electrode, according to the techniques of the present disclosure. [Figure 17] A schematic drawing showing a fourth exemplary electrode configuration for an exemplary end effector that includes a rectangular elongated ablation electrode interrupted by a diagnostic electrode, according to the techniques of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The following detailed description is to be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings are not necessarily to scale, and show selected embodiments and are not intended to limit the scope of the present disclosure. The detailed description is by way of example and not limitation, and illustrates the principles of the technology of the present disclosure. This description enables one skilled in the art to make and use the technology of the present disclosure, and describes some embodiments, adaptations, variations, alternatives, and uses of the technology of the present disclosure, including what is currently considered to be the best mode of carrying out the technology of the present disclosure.
[0014] Where used herein, the terms “about,” “approximately,” or “generally” for any number or range indicate a preferred dimensional tolerance that enables some or all of the components to function for the intended purpose described herein. More specifically, “about” or “approximately” may refer to a range of values within ±20% of the stated value; for example, “about 90%” may refer to a range of values between 71% and 110%. In addition, where used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject, and while the use of the subject technology in a human patient represents a preferred embodiment, it is not intended to limit the system or method to human use. Similarly, the term “proximal” indicates a location closer to the operator or physician, while “distal” indicates a location further away from the operator or physician.
[0015] As discussed herein, the vascular systems of “patient,” “host,” “user,” and “subject” can be human or any animal vascular system. It should be understood that animals can be any applicable type, including but not limited to mammals, veterinary animals, domestic animals, or pet animals. For example, an animal could be a laboratory animal specifically selected to have certain characteristics similar to humans (e.g., rats, dogs, pigs, monkeys, etc.). It should be understood that a subject could be, for example, any applicable human patient.
[0016] As discussed herein, “Operator” may include physicians, surgeons, technicians, scientists, or any other individuals or delivery devices associated with the delivery of a multi-electrode catheter for the treatment of drug-refractory atrial fibrillation to a subject.
[0017] As discussed herein, the terms “to ablate” or “ablation,” in the context of the devices and corresponding systems of this disclosure, refer throughout this disclosure to components and structural features configured to reduce or prevent the generation of irregular cardiac signals within cells by utilizing non-thermal energy, such as pulsed electric field (PEF) and irreversible electroporation, interchangeably referred to as pulsed-field ablation. In the context of the devices and corresponding systems of this disclosure, “to ablate” or “ablation” is used throughout this disclosure to refer to non-thermal ablation of cardiac tissue in a particular condition, including but not limited to arrhythmias, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The terms “to ablate” or “ablation” also include known methods, devices, and systems for achieving various forms of body tissue ablation, as will be understood by those skilled in the art.
[0018] As discussed herein, when the terms “bipolar” and “monopole” are used to refer to ablation schemes, they describe different ablation schemes with respect to the current path and electric field distribution. “Bipolar” refers to an ablation scheme that utilizes a current path between two electrodes, both placed at the treatment site. The current density and electric flux density are typically approximately equal in each of the two electrodes. “Monopole” refers to an ablation scheme that utilizes a current path between two electrodes, where one electrode with a high current density and high electric flux density is placed at the treatment site, and a second electrode with a relatively low current density and lower electric flux density is placed at a distance from the treatment site.
[0019] As discussed herein, the terms “biphasic pulse” and “monophase pulse” refer to the respective electrical signals. A “biphasic pulse” refers to an electrical signal having a positive voltage phase pulse (referred to herein as the “positive phase”) and a negative voltage phase pulse (referred to herein as the “negative phase”). A “monophase pulse” refers to an electrical signal having only a positive phase or only a negative phase. Preferably, the system providing the biphasic pulse is configured to prevent the application of direct current (DC) to the patient. For example, the average voltage of the biphasic pulse may be zero volts relative to ground or other common reference voltage. Each phase of the biphasic and monophasic pulses preferably has a square shape with an essentially constant voltage amplitude for most of the phase duration. The phases of the biphasic pulse may be temporally separated by an interphase delay.
[0020] As discussed herein, the terms “tubular” and “tube” are to be interpreted broadly and are not limited to right cylindrical structures, structures with a strictly circular cross-section, or structures with a uniform cross-section over their entire length. For example, tubular / shaft structures are generally illustrated as substantially right cylindrical structures. However, tubular / shaft structures may have tapered or curved outer surfaces without departing from the scope of this disclosure.
[0021] This disclosure relates to systems, methods, uses, and devices for mapping and ablation of cardiac tissue to treat cardiac arrhythmias. Ablation energy is typically delivered to cardiac tissue by a catheter tip capable of delivering ablation energy along the tissue to be ablated. Some exemplary catheters include a three-dimensional structure in their tip and are configured to manage ablation energy from various electrodes positioned on the three-dimensional structure. Ablation procedures incorporating such exemplary catheters can be visualized using fluoroscopy.
[0022] Cardiac tissue ablation, which involves applying radiofrequency (RF) energy and thermal techniques such as cryoablation, is a well-known procedure for improving a dysfunctional heart. Typically, to successfully ablate using thermal techniques, it is necessary to measure electrocardiograms at various locations in the myocardium. In addition, temperature measurements during ablation provide data that enables the effectiveness of the ablation. In ablation procedures using thermal techniques, electrode potentials and temperature are usually measured before, during, and after the actual ablation. RF approaches can carry risks that can lead to tissue carbonization, combustion, steam popping, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistula. Cryoablation is an alternative approach to RF ablation that can reduce some of the thermal risks associated with RF ablation. However, operating cryoablation devices and selectively applying cryoablation is generally more difficult than RF ablation. Therefore, cryoablation is not feasible in certain anatomical shapes that can be reached by electroablation devices.
[0023] This disclosure may include electrodes configured for RF ablation, cryoablation, or irreversible electroporation (IRE). Throughout this disclosure, IRE may be interchangeably referred to as pulsed field (PEF) ablation and pulsed field ablation (PFA). The IRE considered in this disclosure is a non-thermal cell death technique that can be used for ablation of atrial arrhythmias. To ablate using IRE / PEF, a biphasic voltage pulse is applied to destroy the cellular structure of the myocardium. The biphasic pulse is a non-sinusoidal waveform and can be tailored to the target cells based on the electrophysiology of the cells. In contrast, to ablate using RF, a sinusoidal voltage waveform is applied to generate heat in the treatment area, indiscriminately heating all cells within the treatment area. Thus, IRE has the ability to save adjacent heat-sensitive structures or tissues, which would be beneficial in reducing the potential complications known in ablation or isolation modalities. Additionally or alternatively, monophasic pulses can be utilized.
[0024] Refer to Figure 1, which shows an exemplary catheter-based electrophysiological mapping and ablation system 10. The system 10 includes multiple catheters that are percutaneously inserted by a physician 24 into a lumen or vascular structure of the heart 12 through the vascular system of the patient 23. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location in the heart 12. Multiple catheters can then be inserted into the delivery sheath catheter to reach the desired location. The multiple catheters may include a catheter dedicated to sensing intracardiac electrophysiological (IEGM) signals, a catheter dedicated to ablation, or a catheter dedicated to both sensing and ablation. An exemplary catheter / medical probe 14 configured to sense IEGM is illustrated herein. To sense a target site in the heart 12, the physician 24 brings the catheter shaft having the distal end 28 (e.g., multilayer end effector 100) of the catheter 14 into contact with the heart wall. For ablation, the physician 24 similarly brings the distal end of an ablation catheter to the target site for ablation.
[0025] The catheter 14 is an exemplary catheter comprising a plurality of electrodes 160 (see Figures 2A and 2B), including an ablation electrode 161 and a diagnostic electrode 165. The diagnostic electrode 165 is positioned proximal to or surrounded by the ablation electrode 161 and is configured to sense IEGM signals and help confirm contact with tissue. In the embodiments described herein, the electrodes 160 may be configured to deliver ablation energy (IRE or RF) to tissue within the heart 12. In addition to delivering ablation energy using the electrodes 160, the electrodes 160 may also be used to determine the location of the end effector 100 or to measure physiological properties such as local surface potential at each location on the tissue within the heart 12. The electrode 160 can be biased so that a wider portion of the electrode 160 faces outward from the end effector 100, thereby allowing the electrode 160 to deliver more electrical energy outward (i.e., towards the tissue of the heart 12) away from the end effector 100 than the amount of electrical energy directed inward towards the end effector 100.
[0026] Examples of materials ideally suited for forming electrodes 160 (including electrodes 161 and 165) include gold, platinum, and palladium (and their respective alloys). These materials also possess high thermal conductivity, which allows minimal heat generated on the tissue (i.e., due to the ablation energy delivered to the tissue) to be conducted through the electrodes to the back side of the electrodes (i.e., the portion of electrode 160 inside the spine), and then to the blood pool within the heart 12. Furthermore, silver epoxy / ink can be used to increase the surface area, reduce impedance, and improve flexibility. In some embodiments, impedance-reducing coatings such as iridium oxide (IrOx) or platinum-iridium (PtIr) alloys can be used.
[0027] The catheter 14 may additionally include a position sensor embedded in or near the distal tip 28 to track the position and orientation of the distal tip 28. Optionally, and preferably, the position sensor is a magnetic-based position sensor including three magnetic coils for detecting three-dimensional (3D) position and orientation.
[0028] A magnetic-based position sensor may operate in conjunction with a position pad 25, which includes a plurality of magnetic coils 32 configured to generate a magnetic field within a given working volume. The real-time position of the distal tip 28 of the catheter 14 may be tracked based on the magnetic field generated by the position pad 25 and sensed by the magnetic-based position sensor. Details of magnetic-based position sensing technology are described in U.S. Patents Nos. 5,391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, and 6,892,091, each of which is incorporated herein by reference. The end effector 100 may further include one or more induction coils configured to provide an electrical signal to a magnetic-based position sensing system for determining the position or orientation of the end effector. For example, the end effector 100 may include an induction loop or coil similar to that shown in Figures 5A and 5B of U.S. Patent Application Publication No. 2024 / 0215894, which is incorporated herein by reference in its entirety and is attached to the appendices herein. In some embodiments, one or more induction coils within the end effector 100 may be used in conjunction with a position sensor to determine the position or orientation of the end effector 100.
[0029] System 10 includes one or more electrode patches 38 positioned for skin contact on a patient 23 to establish a position reference for the position pad 25 and impedance-based tracking of the electrodes 160. For impedance-based tracking, a current is directed to the electrodes 160 and sensed in the electrode skin patches 38, thereby allowing the position of each electrode to be triangulated through the electrode patches 38. Details of the impedance-based location tracking technology are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865 and 8,456,182, each of which is incorporated herein by reference.
[0030] The recorder 11 displays the electrophysiogram 21 captured by the surface ECG electrode 18 and the intracardiac electrophysiogram (IEGM) captured by the electrode 160 of the catheter 14. The recorder 11 may include pacing capabilities for pacing the rhythm of the heart, or may be electrically connected to a standalone pacer.
[0031] System 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more electrodes 160 located at the distal tip of a catheter configured for ablation. The energy generated by the ablation energy generator 50 may include, but is not limited to, radio frequency (RF) energy or pulsed field ablation (PFA) energy, or a combination thereof, including unipolar or bipolar high-voltage direct current (DC) or alternating current (AC) pulses, which may be used to induce irreversible electroporation (IRE). The ablation energy generator 50 is preferably configured to provide a biphasic bipolar pulse to induce IRE while maintaining the tissue temperature below the thermal ablation temperature. Additionally or alternatively, the ablation energy generator 50 may be configured to provide a single-phase IRE pulse, a single-polar IRE pulse, a thermal ablation electrical signal, or a combination thereof. For example, the ablation energy generator 50 may be configured to provide pulses similar to those described in U.S. Patent Publication Nos. 2021 / 0169550(A1), 2021 / 0177503(A1), 2021 / 0186604(A1), and 2023 / 0009191(A1), and U.S. Patent No. 11,540,877(B2), each of which is incorporated herein by reference in whole and attached to the appendices herein. U.S. Patent No. 11,540,877(B2) corresponds to U.S. Patent Publication No. 2021 / 0161592(A1), which is incorporated herein by reference in whole.
[0032] For example, as described in U.S. Patent No. 11,540,877(B2), the generator 50 may be configured to apply a bipolar pulse having an amplitude sufficient to cause IRE in the tissue contacted by the electrode, and RF energy having sufficient power to thermally ablate the tissue contacted by the electrode. In some embodiments, the sequence of bipolar pulses includes pulses having an amplitude of at least 200 V, and the duration of each bipolar pulse is less than 20 μs. Additionally or alternatively, the RF signal has a frequency of 350 to 500 kHz and an amplitude of 10 to 200 V. The end effector may further include a temperature sensor, and the electrical signal generator may be configured to apply a signal in response to the temperature measured by the temperature sensor. In some embodiments, the IRE signal may have parameters as shown in Table 1 of U.S. Patent No. 11,540,877(B2). It should be noted that the “bipolar pulse” described in U.S. Patent No. 11,540,877(B2) is referred to herein as a “two-phase pulse” relating to the shape of an electrical signal, whereas the “bipolar pulse” as described herein relates to the arrangement of electrodes receiving the pulse as defined above.
[0033] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, the electrophysiological equipment, the power supply, and the workstation 55 that controls the operation of the system 10. The electrophysiological equipment of the system 10 may include, for example, multiple catheters, position pads 25, surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally, and preferably, the PIU 30 additionally includes processing capabilities for implementing real-time calculation of catheter position and performing ECG calculations. The PIU 30 can control the generator 50 to provide electrical energy to the ablation electrodes of the end effector 100 in accordance with the ablation protocols described above and in the incorporated references above. The PIU 30, workstation 55, and generator 50 can be collectively considered as an ablation system console having one or more output ports configured to provide ablation energy to ablation electrodes, one or more processors, and a non-transient computer-readable medium that communicates with the processors to cause the ablation system console to provide ablation energy as described above and in the following embodiments of this specification.
[0034] The workstation 55 includes memory, a processor unit having memory or storage devices loaded with appropriate operating software, and user interface functions. The workstation 55 may optionally provide several functions, including (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering the model or anatomical map 20 for display on a display device 27, (2) displaying activation sequences (or other data) compiled from recorded electrophoresis diagrams 21 on the display device 27 as a representative visual representation or image superimposed on the rendered anatomical map 20, (3) displaying the real-time position and orientation of multiple catheters within the cardiac chambers, and (5) displaying sites of interest, such as the locations where ablation energy has been applied, on the display device 27. One commercially available product embodying the elements of system (10) is available as the CARTO® 3 system, commercially available from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618, USA.
[0035] In some embodiments, system 10 further includes an irrigation system configured to irrigate during IRE. In some embodiments, PIU 30 is configured to control the irrigation system to provide irrigation to a catheter end effector, as described in U.S. Patent Application Publication No. 2021 / 0196372(A1), the entirety of which is incorporated herein by reference and attached to the appendices herein. The irrigation fluid can exit from the distal end of catheter 14 through a port at the distal end of shaft 80 or through a hole in the body of end effector 100.
[0036] Figure 2A is a schematic diagram showing a distal perspective view of the distal tip 28 of the catheter 14. Figure 3 is a schematic diagram showing a proximal perspective view of the distal tip 28 of the catheter 14. Figure 4A is a schematic diagram showing a cross-sectional view of a portion of the distal tip 28.
[0037] It should be noted that Figure 4A, and other cross-sectional views in this application, show the illustrated portion of the end effector 100 in a flat / planar state. However, those skilled in the art will understand that these figures are merely intended to convey to the reader the potential configuration of the electrodes 160 or layers of the end effector 100. When in use, the end effector has an umbrella-like shape (described in more detail below), and therefore a more technically accurate depiction of the cross-sectional view of the end effector 100 would be that the shape is either substantially arched or angularly bent at the spine 122 of the end effector 100 (described in more detail below).
[0038] Referring here to Figures 2A and 3, the distal tip 28 (Figure 1) of the catheter / medical probe 14 includes an end effector 100 extending along the longitudinal axis 60 from an elongated probe shaft 80. In some embodiments, the probe shaft 80 carries the aforementioned irrigation system. The end effector 100 includes a spine framework 120 extending along the longitudinal axis 60.
[0039] The framework 120 includes a mounting section 121 connected to the probe shaft 80, and a plurality of spines 122 extending radially outward from the mounting section 121 and the longitudinal axis 60. In the example of Figures 2A and 3, each spine has a fixed end (to the mounting section 121) and a free distal end 122-1. In this embodiment, eight spines 122 are used and are arranged angularly / radially around the longitudinal axis 60. However, any suitable number of spines (i.e., at least three) can be used without departing from the spirit and scope of this disclosure, provided that they can support the three-dimensional structural membrane 130 (discussed in more detail below).
[0040] In some embodiments, the framework 120 is a single (i.e., monolithic) structure. In such embodiments, the framework 120 can be formed from a planar or cylindrical tubular stock of material using any preferred method. For example, the framework 120 can be formed by cutting, laser cutting, stamping, a combination thereof, etc., so that it is divided to form a spine 122 and define a mounting section 121. In other embodiments, the spine 122 may be a separate member converging at the mounting section 121.
[0041] The framework 120 may include a flexible elastic material (e.g., a shape memory alloy such as nickel-titanium, also known as nitinol or stainless steel) shaped to be biased to bend outward toward the extended configuration, as shown in Figures 2 and 3. The spines 122 may be curved or may extend substantially linearly outward toward their respective distal ends 122-1. In the extended configuration, the framework 120 resembles the ribs of an umbrella. Due to the flexible elastic nature of the material, the spines 122 can also move into a folded configuration (an example of a folded configuration can be seen in Figure 12) in which the spines 122 extend substantially along the longitudinal axis 60.
[0042] The end effector further includes a flexible membrane 130 connected to the framework 120 and extending to the distal end 130-1. Specifically, the membrane 130 is connected to each spine 122 such that the distal end 130-1 surrounds / encompasses the longitudinal axis 60, and the spines 122 bias the membrane 130 into an extended configuration and also move it into a folded configuration. As seen in Figures 2-3, the distal end 130-1 of the membrane extends beyond the distal end 122-1 of the spine 122. This membrane 130 also serves to enhance the non-traumatic nature of the tip of the end effector 100 and to protect the object from sharp edges. The membrane 130 may include flexible biocompatible materials such as polymers. Further uses, advantages, and materials of the membrane 130 will be detailed later in this specification. Note that the flexible film 130 in Figures 4A to 7 and Figure 10 is shown without cross-sectional hatching to make it easier to distinguish the components shown in each figure.
[0043] The film 130 may include one or more sheets / layers that are adjacent to and fused together with the framework 120 to form a single continuous, generally planar insulating mass 130. For example, the film 130 may include a first layer 132 forming the distal outer surface of the end effector 100, a second layer 134 forming the proximal outer surface of the end effector 100, and a third layer 136 positioned between the first layer 132 and the second layer 134. As best seen in Figure 3, the second layer 134 defines a volume V having an open end (i.e., the proximal side of volume V) due to the overall shape of the end effector 100 in the extended configuration.
[0044] In some embodiments, one or more layers of the membrane 130 (e.g., a third layer 136) include a dielectric material. For example, it may include a highly dielectric sheet / tile or be formed using highly dielectric TPU doping. The various configurations shown in the figure provide different levels of electrical insulation between the electrodes on both sides of the membrane 130. The electrical insulation may be adjusted to direct the electric field lines between the bipolar pairs of ablation electrodes on both sides of the membrane 130 during PFA application, thereby directing the electroporation of cells in the target tissue.
[0045] The membrane 130 can be thermoformed around the first flexible circuit 110 (Figure 4A, described in more detail below), the second flexible circuit 150 (Figure 4A, described in more detail below), and at least a portion of the framework 120, making it easier to manufacture the end effector 100 compared to other labor-intensive processes. The polymer may include TPU, silicone, or other thermoforming or fabrication materials suitable for such thermoforming. In the extended configuration, the membrane 130, by its connection to the spines 122, forms a substantially hemispherical or semiconical shape similar to the shape of an umbrella canopy. It should be further noted that, depending on the tension of the membrane 130 wrapped around the spines 122, the shape may resemble a polygonal pyramid (for example, an octagonal pyramid if there are eight spines 122). Folding the umbrella shape from the extended configuration can be achieved by the engagement between the spines 122 and the delivery sheath when the end effector 100 is pulled in the proximal direction. In some embodiments, the spine 122 can be inverted so that its distal end 122-1 points distally when folded. In other embodiments, an actuator may be connected to the framework to move the spine 122 simultaneously into a folded or extended configuration. The umbrella shape having a solid / continuous membrane configuration helps to keep the electrodes 160 separated from each other by a known distance, which is important for the selection of damage formation and ablation parameters.
[0046] Referring to Figures 2A and 34A, the end effector 100 further includes a first flexible circuit 110 and a second flexible circuit 150 extending radially around the longitudinal axis 60, for example, in a sunray pattern. Each flexible circuit 110, 150 includes flexible substrates 111, 151 (i.e., a first flexible substrate layer 111 and a second flexible substrate layer 151) which may be continuous flexible circuit members extending completely or substantially completely around the longitudinal axis 60, or each flexible circuit 110, 150 / flexible substrate 111, 151 may be subdivided into a plurality of flexible circuit sections that extend together around the longitudinal axis 60 and are circumferentially spaced apart from one another. Each of the first flexible circuit 110 and the second flexible circuit 150 includes a plurality of electrodes 160 electrically connected to the PIU 30 via electrical interconnections (e.g., traces). If the flexible circuits 110, 150 are subdivided into multiple sections, each of these sections may be located near the spine 122, and each of the flexible substrates 111, 151 may include electrodes 160 on it. Note that, although not explicitly shown, the end effector 100 may also include other layers, such as a position-sensing loop layer for sensing the position or shape of the end effector 100.
[0047] Each of the flexible substrate layers 111, 151 contains a biocompatible material. In some embodiments, each flexible substrate layer 111, 151 is formed entirely or almost entirely from a biocompatible material. In some embodiments, the flexible substrate layer is formed from polyimide, copper, LCP, nitinol substrate, thermoplastic polyurethane (TPU), silicone, thermosetting resin, or other polymer substrate. In some embodiments, each flexible substrate layer 111, 151 described herein can be made primarily from polyimide. In other embodiments, it can be made from biocompatible polyimide, glass-reinforced epoxy laminate, copper, or graphene, either alone or in combination.
[0048] As described above, the flexible circuits 110 and 150 are arranged on a film 130 that extends around the longitudinal axis 60. More specifically, the first flexible circuit 110 is arranged on the first surface 136A of the film 130 (facing away from the longitudinal axis 60), and the second flexible circuit 151 is arranged on the second surface 136B of the film 130 (facing toward the longitudinal axis 60) on the opposite side of the first surface 136A (relative to the spine 122).
[0049] Furthermore, the membrane 130 can be continuous with the contact surfaces such that only the contact surfaces of at least some of the electrodes 160 are exposed to the ambient environment. The contact surfaces of the electrodes 160 may be coplanar with the outer surface of the membrane 130, recessed relative to the outer surface of the membrane 130, or protruding from there. As used herein, “ambient environment” refers to the external environment such as the organ in which the end effector 100 is placed, or an operating room before it is placed inside a biological organ. The membrane 130 at least partially encapsulates or separates different layers of the end effector 100 (e.g., flexible circuits 110, 150 (including substrate layers 111, 151) and framework 120) along the vertical axis 62. See, for example, Figure 4A, which shows flexible circuits 110, 150 separated from the spine 122 via a third layer 136 of the membrane 130 placed between the flexible circuits 110, 150 and the spine 122.
[0050] It should be noted that all electrodes 160 on the flexible circuits 110, 150 described herein do not need to be exposed through the insulating material 130, as these unexposed electrodes may be used to sense far-field signals for noise reduction in proximity to the tissue contact electrodes. Similarly, far-field signals containing noise or artifacts can be reduced or canceled out against the entire end effector, which has a reference electrode that does not come into contact with tissue and only with blood.
[0051] Continuing to refer to Figures 2A and 3-4A, the electrode 160 comprises multiple ablation (or treatment) electrode sets 161, each ablation electrode set 161 positioned proximal to its respective spine 122. These associated spines 122 and electrodes 160 are referred to as an electrode / spine region (or electrode and spine region). As is most commonly seen in Figure 4A, in some embodiments, not all spines 122 have associated electrode sets. Examples in Figures 2A and 3-4A present an end-effector 100 in which an alternating pattern of ablation electrodes 161 adjacent to spines 122 and ablation electrodes 161 not adjacent to spines 122 is used. In other words, in this example, there are more spines 122 than sets of ablation electrodes 161 (e.g., twice the number of spines 122 compared to sets of electrodes 161). In the example shown in Figure 2A, there are four electrode / spine regions 102A to 102D (i.e., the first electrode / spine region 102A, the second electrode / spine region 102B, the third electrode / spine region 102C, and the fourth electrode / spine region 102D).
[0052] Figures 2B and 4B show modified diagrams similar to those in Figures 2A and 4A, respectively, where each spine 122 has an associated electrode set. In other words, in the examples of Figures 2B and 4B, there are an equal number of sets of spines 122 and ablation electrodes 161. In the example of Figure 2B, there are eight electrode / spine regions 102A to 102H (i.e., the first electrode / spine region 102A, the second electrode / spine region 102B, the third electrode / spine region 102C, the fourth electrode / spine region 102D, the fifth electrode / spine region 102E, the sixth electrode / spine region 102F, the seventh electrode / spine region 102G, and the eighth electrode / spine region 102H), but in other respects, the structure is the same as in the examples of Figures 2A and 3 to 4A. Therefore, it will be understood by those skilled in the art that, for example, the explanation of the electrode configuration in Figure 4A also applies to the electrode configuration in Figure 4B unless otherwise specified.
[0053] Each electrode in each ablation electrode set 161 is perpendicularly spaced (along the vertical axis 62) from its associated / adjacent spine 122. As seen in Figures 2A and 3-4A, each ablation electrode 161 is positioned on the side of its associated / adjacent spine 122 in its electrode / spine region and extends along its predetermined length.
[0054] The left side of Figure 4A shows exemplary electrode configurations on both sides (upper and lower) of an exemplary end-effector 100, including an elongated ablation electrode 161, with each ablation electrode defining a treatment area. Although not shown in this figure, a diagnostic electrode 165 may be positioned within the two ablation electrode areas (see, for example, Figure 14 discussed below) or outside the treatment area, a tissue-contact electrode (discussed in more detail below) may be positioned between the two upper ablation electrode areas, and a reference electrode (discussed in more detail below) may be positioned within the area of the end-effector 100 that does not contact tissue.
[0055] The axis of each spine 122 can serve as a line of symmetry for its respective associated electrode 160 (i.e., the electrode 160 positioned proximal to it). As shown in the figure, the electrode configuration is symmetric with respect to the spine 122. Preferably, at least the ablation electrodes 161 are symmetric with respect to the spine 122. In alternative examples, the electrode configuration may not be symmetric with respect to the line of symmetry.
[0056] As shown in Figure 4A, in some embodiments, each ablation electrode set 161 may include four electrodes 161A-161D (also referred to herein as treatment or ablation electrodes), including a first ablation electrode 161A, a second ablation electrode 161B, a third ablation electrode 161C, and a fourth ablation electrode 161D. The first ablation electrode pair 161A, 161B are positioned on the first flexible circuit 110, relative to each other and proximal to their associated spines 122. Similarly, the second ablation electrode pair 161C, 161D are positioned on the second flexible circuit 150, relative to each other and proximal to their associated spines 122, with a membrane 130 between them so as to define a mirror image configuration. The first ablation electrode pair 161 is configured to be positioned relative to the tissue during treatment. When the upper side of the end effector 100 is in contact with tissue, the corresponding electrodes 161C and 161D on the opposite side are in contact with body fluid (e.g., blood) and can function as reference electrodes for electrodes 161A and 161B that are in contact with tissue.
[0057] The section of the membrane 130 shown in Figure 4A, proximal to spine 122, has a left half to the left of the line of symmetry and a right half to the right of the line of symmetry. The first ablation electrode 161A defines a first electrode region that is entirely to the left of its associated spine 122. The second ablation electrode 161B defines a second electrode region that is entirely to the right half of its associated spine 122. The third and fourth ablation electrodes 161C and 161D similarly define third and fourth electrode regions that are entirely to the left and right of spine 122, respectively.
[0058] The ablation electrodes 161A-161B can take on several shapes / designs, such as being serpentine, provided as strips, provided as bars, or provided as connected bars. Figures 14-17 show exemplary configurations, which are described in more detail below. Generally, the ablation electrodes 161C, 161D are shown on the second (lower) side opposite to the first (upper) side ablation electrodes 161A, 161B. The opposite side ablation electrodes 161C, 161D overlap with the first side ablation electrodes 161A, 161B, preferably overlapping with a large portion of the first side ablation electrodes 161A, 161B, and may be symmetrical with the first side ablation electrodes 161C, 161D with respect to the plane defined by the film 130 when placed flat (for example, as shown in Figure 4A for illustrative purposes). The cross-section of the end effector 100 is simplified for illustrative purposes, but does not limit, to omit certain features such as electrical traces. The ablation electrodes 161A-161D are shown submerged within the film 130, but alternatively, they may protrude from the film on each of their respective sides. The ablation electrodes 161A-161D may have approximately equal surface areas.
[0059] In some embodiments, the ablation electrodes 161A–161D have a length of at least half the total radius of the end effector 100 when measured from the distal end 130-1 of the flexible membrane 130 to the mounting section 121. In some embodiments, the ablation electrodes 161A–161D extend to approximately the distal end 130-1 of the flexible membrane 130-1.
[0060] The ablation electrodes 161A-161D of each set are connected to the ablation energy generator 50. Multiple ablation configurations can be employed using the configurations detailed herein. In some embodiments, as described above, the ablation electrodes 161C, 161D on the second side can function as respective reference electrodes for the electrodes 161A, 161B on the opposite side of the first side of the membrane 130 when the first side is in contact with the tissue. Additionally or alternatively, the ablation electrodes 161 on both sides can be paired to provide a bipolar PFA electrical signal between the paired ablation electrodes 161. Additionally or alternatively, electrodes 161 on the same side can be paired to provide a bipolar PFA electrical signal between the paired electrodes. The bipolar PFA electrical signal may be monophasic or biphasic. Although each pair of first electrodes (161A, 161B) is described as an individual electrode, it should be noted that it is within the scope of the claimed art that both electrodes in each of the first pairs (e.g., 161A, 161B) or second pairs (e.g., 161C, 161D) are electrically connected to form a single ablation electrode. Specifically, the first electrode pairs 161A, 161B can be electrically connected to each other via the spine 122 between the electrodes or directly in the generator 50 to define a single first electrode among a plurality of first electrodes arranged on the first surface of the film. Similarly, the second electrode pairs 161C and 161D can be electrically connected to each other via the spine 122 between them or directly in the generator 50 to define a single second electrode among a plurality of second electrodes arranged on the second surface of the film. It should be further noted that each of electrodes 161A, 161B, 161C, and 161D may be configured as a diagnostic electrode (receiving electrical signals from tissue instead of transmitting electrical signals from a generator for ablation).
[0061] The illustrated end effector 100 includes an optional diagnostic electrode 165 on the first side of a membrane 130 electrically insulated from the ablation electrode 161. The diagnostic electrode 165 is configured to receive electrical signals from the tissue in order to map the cardiac tissue and detect arrhythmias. As shown in the illustration, the diagnostic electrodes 165 are arranged in pairs, with a first diagnostic electrode 165 on the left side of each spine 122 and a second diagnostic electrode 165 on the right side of each spine 122.
[0062] The end effector 100 may include any tissue contact quality electrodes arranged in closely spaced pairs such that the impedance measured across each tissue contact quality electrode pair indicates that both electrodes of that pair are in contact with the tissue.
[0063] The end effector 100 includes an optional reference electrode (primarily described as a diagnostic electrode, but note that reference no. 165 may also be considered to refer to an exemplary reference electrode or any other electrode discussed herein) positioned on the first side of the membrane 130. Additionally or alternatively, the end effector 100 may include a reference electrode similarly positioned on the membrane on the second side. The reference electrode may be used for ECG acquisition or as a reference in either a unipolar or bipolar (split or proximity pair) configuration. Its number may be as few as four per side, but may be more as needed (to accommodate trace limitations). Signals from the reference electrodes may also be used for contact information to determine which parts of the paddle are in contact with or near tissue. The end effector 100 includes one or more sections lacking an ablation electrode. A reference electrode may be positioned in this section. As discussed herein, an ablation electrode, diagnostic electrode, or tissue contact electrode may be used as a reference electrode for the corresponding electrode on the opposite side that is in contact with tissue. Each of these electrodes is positioned on the distal portion of the end effector 100 and can therefore be positioned in contact with tissue if so desired by the physician 24. Preferably, the reference electrode is positioned so that the physician 24 cannot, or at least very unlikely, position the reference electrode in contact with tissue, but nevertheless is positioned relatively close to the electrode configured to contact tissue.
[0064] In some embodiments, at least the ablation electrode, diagnostic electrode, and tissue contact electrode are coplanar with the outer surface of the film 130, providing a first coplanar surface to the end effector 100 corresponding to the first side of the film 130 and a second coplanar surface to the end effector 100 corresponding to the second side of the film 130. Any combination of the ablation electrode 161 and the other electrodes 165 (as discussed herein) may include an exposed conductive layer in a flexible printed circuit board, or it may include silver epoxy or conductive ink.
[0065] Further details regarding the exemplary configuration of the electrodes can be found in the explanation of Figures 14 to 17.
[0066] As described above, the film 130 may include a third layer 136 between the first / upper and second / lower sides of the end effector 100. The third layer may include polymer body regions extending the width of the respective regions associated with each ablation electrode set 161 and spine 122. In some embodiments, such as when the flexible circuits 110, 150 are embodied as separate discontinuous circuits, the third layer 136 may connect adjacent flexible circuits 110, 150 and be provided as respective thinned polymer-filled regions lacking a framework or any electrical circuitry. When configured in this way, the film 130 can provide additional electrical insulation between the electrodes on both sides of the end effector 100 while maintaining sufficient flexibility for operations for positioning relative to the tissue and transporting through the sheath (compared to examples including openings as seen in Figures 9-10). As described above, this third layer 136 may also be embodied as a high-dielectric layer between each side and extending around the end effector 100. The dielectric layer 134 overlaps and is parallel to each of the ablation electrodes 161A-161D. The high dielectric layer comprises a ceramic-doped polymer and, compared to the polymer alone, can provide additional electrical insulation between the electrodes on both sides of the film 130 while still providing sufficient flexibility. Some portions of the end effector 100 are the high dielectric layer 134 and may lack a framework and electrical circuits. In some embodiments, a third layer 134 may be embodied as a high dielectric tile between each side and configured to overlap so as to fold together with the end effector 100 into the delivery sheath. The high dielectric tile may include a ceramic plate that extends longitudinally through each segment of the body and overlaps between segments. The high dielectric tile or longitudinally extending ceramic plate may be angled with respect to the plane defined by the film 130 when placed flat, such that the tile / plate overlaps longitudinally with respect to each other when the end effector retracts into the sheath.
[0067] Figures 5A to 5C show exemplary ablation configurations for the application of bipolar PFA electrical pulses in an example where the end effector includes four ablation electrodes 161A to 161D. In these figures, the first and second ablation electrodes 161A and 161B face outward toward the tissue, while the third and fourth ablation electrodes 161C and 161D (located within volume V) face away from the tissue. During use, the first and second ablation electrodes 161A and 161B can be in contact with (or positioned directly adjacent to) the tissue, and the ablation energy generator 50 selectively activates pairs of ablation electrodes to apply pulsed-field ablation pulses. In some embodiments, the pulses have a voltage of approximately 600 volts (V) to approximately 1,200 V. In other embodiments, the pulses have a voltage of 600 V to 2,600 V. In some embodiments, the bipolar PFA electrical signal comprises 60 pulses having a magnitude of about 1,200 V and a total duration of about 4 seconds. In some embodiments, the bipolar pulses may include an inter-pulse delay of about 2 microseconds. The pattern of ablation electrode pairs may be adapted based on the total number of ablation electrodes in the end effector 100, as will be discussed in more detail as can be understood by those skilled in the art who are informed by the disclosure herein.
[0068] Figure 5A shows one such exemplary ablation configuration. In this example, the ablation electrodes 161A-161B are operated diagonally / across the body and sequentially. The generator 50 can alternately energize the first pair of ablation electrodes 161 so that only one pair of ablation electrodes 161 in each set is activated at a time, by applying a pulse between the first ablation electrode 161A(+) and the fourth ablation electrode 161D(-), and then energize the second pair of ablation electrodes 161 so that a pulse is applied between the second ablation electrode 161B(+) and the third ablation electrode 161C(-).
[0069] In this example, the ablation electrode pair 161 is symmetrical with respect to spine 122 and is located on both sides of the membrane 130. A voltage is applied across the electrode pairs in the electrode region, for each pair, the ablation electrode in the first electrode region is in contact with the tissue, and the other electrode region is on the opposite side of the end effector and extends from the first electrode region across spine 122. Figure 5A shows the positively charged ablation electrode 161A, while the ablation electrode pair 161D is negatively charged. This shows a positive voltage pulse configured to induce electroporation in the tissue in contact with the upper side of the membrane 130. A biphasic pulse may be applied, in which case the polarity switches or alternates between the positively charged ablation electrode 161D, which is not in contact with the tissue, and the negatively charged ablation electrode 161A, which is in contact with the tissue, as shown in Figure 5A. As shown in Figure 5A, a series of bipolar pulses (which may include biphasic or monophasic pulses) can be applied between the bipolar ablation electrode pairs 161A and 161D, and then, in the same manner as described above, a series of bipolar pulses can be applied between the other bipolar ablation electrode pairs 161B and 161C.
[0070] In other words, Figure 5A shows an end effector 100 configured to provide an electrical pulse with an amplitude of 600–1,200V between a bipolar pair including an ablation electrode located above the membrane 130 and in contact with the tissue (e.g., a first ablation electrode 161A) and an ablation electrode located below the membrane 130 and not in contact with the tissue (e.g., a fourth ablation electrode 161D). Similarly, ablation electrodes 161B, 161C can be paired.
[0071] In some embodiments, cardiac electrical signals may be measured from one or more diagnostic electrodes positioned on the side of the membrane 130 that is in contact with tissue. In some embodiments, tissue contact may be measured from a pair of tissue contact electrodes positioned on the side of the membrane 130 that is in contact with tissue. In some embodiments, a reference electrical signal may be measured from a reference electrode positioned on the side of the membrane 130 that is in contact with tissue, but the reference electrode itself is not in contact with tissue.
[0072] Figure 5B shows another exemplary ablation configuration. In this example, instead of applying pulses obliquely, the pulses are applied perpendicularly (with respect to the orientation in Figure 5B) so that each ablation electrode pair overlaps on both sides of the membrane 130. The generator 50 can simultaneously or alternately energize the first ablation electrode pair 161 to apply pulses between the first ablation electrode 161A(+) and the third ablation electrode 161C(-), and similarly energize the second ablation electrode pair 161 to apply pulses between the second ablation electrode 161B(+) and the fourth ablation electrode 161D(-). The voltage is applied across the ablation electrodes 161A and 161B that are in contact with the tissue and to the ablation electrodes 161C and 161D that are on the opposite side of the membrane 130 and not in contact with the tissue. A biphasic pulse may be applied, in which case the polarity switches or alternates, as shown in Figure 5B, with positive charges on ablation electrodes 161C, 161D that are not in contact with tissue, and negative charges on ablation electrodes 161A, 161B that are in contact with tissue. A series of bipolar pulses may be applied between a pair of bipolar ablation electrodes. As shown, both ablation electrodes 161A, 161B that are in contact with tissue can be activated simultaneously. Alternatively, a series of bipolar pulses may be applied to the first pair of ablation electrodes (161A, 161C) while the second pair (161B, 161D) is de-energized, and then a series of bipolar pulses may be applied to the second pair of ablation electrodes while the first pair is de-energized.
[0073] Figure 5C shows yet another exemplary ablation configuration. In this example, instead of applying pulses diagonally or vertically, the pulses are applied horizontally (relative to the orientation in Figure 5B) across the upper electrode pair. In other words, each ablation electrode pair 161 is symmetrical with respect to the spine 122 and is on the same side of the membrane 130. Specifically, the generator 50 can energize the upper pair of ablation electrodes 161 to apply pulses between the first ablation electrode 161A(+) and the second ablation electrode 161B(-), while the third and fourth ablation electrodes 161C, 161D are not activated. As shown, the voltage is applied across the ablation electrodes 161A, 161B on the lateral membrane 130 that is in contact with the tissue. The ablation electrodes 161C, 161D that are not in contact with the tissue can function as reference electrodes. A biphasic pulse may be applied, in which case the polarity switches or alternates, as shown in Figure 5C, with a positive charge on the right ablation electrode 161B and a negative charge on the left ablation electrode 161A. A series of bipolar pulses may be applied between the bipolar ablation electrode pair 161A, 161B.
[0074] It should be noted that cross-region ablation pulses having a pattern similar to those described with respect to Figures 5A and 5C can be used without departing from the spirit and scope of this disclosure. For example, referring to the example in Figure 2A having four electrode / spine regions 102A to 102D, a series of bipolar pulses (which may include biphasic or monophasic pulses as described above) are applied between one or more ablation electrodes 161 in the first electrode / spine region 102A and one or more ablation electrodes 161 in the second electrode / spine region 102B, and then between one or more ablation electrodes 161 in the second electrode / spine region 102B and one or more in the third electrode / spine region 102C A series of bipolar pulses can be applied between the ablation electrode 161 and the following: a series of bipolar pulses can be applied between one or more ablation electrodes 161 in the third electrode / spine region 102C and one or more ablation electrodes 161 in the fourth electrode / spine region 102D; and a series of bipolar pulses can be applied between one or more ablation electrodes 161 in the fourth electrode / spine region 102G and one or more ablation electrodes 161 in the first electrode / spine region 102H. As a further example, referring to the example in Figure 2B having eight electrode / spine regions 102A to 102H, a series of bipolar pulses (which may include biphasic or monophasic pulses as described above) are applied between one or more ablation electrodes 161 in the first electrode / spine region 102A and one or more ablation electrodes 161 in the second electrode / spine region 102B, followed by one or more ablation electrodes 161 in the third electrode / spine region 102C and one or more in the fourth electrode / spine region 102D. A series of bipolar pulses can be applied between the ablation electrode 161 of the fifth electrode / spine region 102E and one or more ablation electrodes 161 of the sixth electrode / spine region 102F, and then a series of bipolar pulses can be applied between one or more ablation electrodes 161 of the seventh electrode / spine region 102G and one or more ablation electrodes 161 of the eighth electrode / spine region 102H.
[0075] Of course, other cross-region ablation patterns can also be used. In another example, continuing to refer to Figure 2B, a series of bipolar pulses (which may include biphasic or monophasic pulses) can be applied between one or more ablation electrodes 161 in the first electrode / spine region 102A and one or more ablation electrodes 161 in the fifth electrode / spine region 102E, followed by a series of bipolar pulses between one or more ablation electrodes 161 in the second electrode / spine region 102B and one or more ablation electrodes 161 in the sixth electrode / spine region 102F, followed by a series of bipolar pulses between one or more ablation electrodes 161 in the third electrode / spine region 102C and one or more ablation electrodes 161 in the seventh electrode / spine region 102G, followed by a series of bipolar pulses between one or more ablation electrodes 161 in the fourth electrode / spine region 102D and one or more ablation electrodes 161 in the eighth electrode / spine region 102H. A similar technique can be applied to the example in Figure 2A.
[0076] In yet another example, the cross-region ablation pulse may have yet another bipole pattern using two or more electrode / spine regions as the positive electrodes of the bipole. As an example, referring to the example in Figure 2A, a series of bipole pulses are applied between the ablation electrodes 161 (functioning as the positive electrodes in the bipole) in the first and second electrode / spine regions 102A, 102B and one or more ablation electrodes 161 (functioning as the negative electrodes in the bipole) in the third electrode / spine region 102C, and then a series of bipole pulses are applied between the ablation electrodes 161 (functioning as the positive electrodes in the bipole) in the second and third electrode / spine regions 102B, 102C and one or more ablation electrodes 161 (functioning as the negative electrodes in the bipole) in the fourth electrode / spine region 102D, and so on. A series of bipolar pulses can be applied between the ablation electrodes 161 in the third and fourth electrode / spine regions 102C and 102D (functioning as the positive electrode in the bipolar system) and one or more ablation electrodes 161 in the first electrode / spine region 102A (functioning as the negative electrode in the bipolar system), and then a series of bipolar pulses can be applied between the ablation electrodes 161 in the fourth and first electrode / spine regions 102D and 102A (functioning as the positive electrode in the bipolar system) and one or more ablation electrodes 161 in the second electrode / spine region 102B (functioning as the negative electrode in the bipolar system).
[0077] As an example, referring to the example in Figure 2B, a series of bipolar pulses are applied between the ablation electrodes 161 (functioning as positive electrodes in the bipolar system) in the first and second electrode / spine regions 102A and 102B and the ablation electrodes 161 (functioning as negative electrodes in the bipolar system) in the fifth and sixth electrode / spine regions 102E and 102F, and then a series of bipolar pulses are applied between the ablation electrodes 161 (functioning as positive electrodes in the bipolar system) in the second and third electrode / spine regions 102B and 102C and the ablation electrodes 161 (functioning as negative electrodes in the bipolar system) in the sixth and seventh electrode / spine regions 102F and 102G. Subsequently, a series of bipolar pulses can be applied between the ablation electrodes 161 in the third and fourth electrode / spine region 102C (functioning as the positive electrode in the bipolarity) and the ablation electrodes 161 in the seventh and eighth electrode / spine region 102G, 102H (functioning as the negative electrode in the bipolarity), and then a series of bipolar pulses can be applied between the ablation electrodes 161 in the fourth and fifth electrode / spine region 102D, 102E (functioning as the positive electrode in the bipolarity) and the ablation electrodes 161 in the eighth and first electrode / spine region 102G, 102A (functioning as the negative electrode in the bipolarity).
[0078] The above examples of ablation configurations are non-limiting and are merely intended to illustrate specific ways in which the techniques described herein may be implemented. In all of the above examples, the goal of the ablation bipolar configuration and ordering is to achieve circumferential damage without the need to reposition the end effector 100.
[0079] Having described various exemplary ablation patterns that may be used, this disclosure now moves on to exemplary alternative physical forms that the electrode 160 or the entire end effector 100 may take. Unless expressly stated otherwise, it will be understood that the ablation configurations described above may be applied similarly to any of the following exemplary end effectors.
[0080] Figure 6 shows a modified example 100.1 of the end effector 100 described above. This example is identical to the one described above, except that a single pair of ablation electrodes is provided instead of a set of four ablation electrodes 161 proximal to the spine 122. Specifically, the first ablation electrode 161A.1 is placed on the first flexible substrate 111, and the second ablation electrode 161B.1 is placed in a mirror configuration on the second flexible substrate 151. This example can use the ablation configuration described with respect to Figure 5B, or the exemplary cross-region ablation pattern described in the previous paragraph. In some embodiments, a single ablation electrode 161A.1 can be placed above each electrode / spine region 102A-102H, and it should be further noted that IRE can be achieved using the cross-region ablation pulse described above.
[0081] Figure 7 shows yet another modification 100.2 of the end effector 100 described above. This modification 100.2 may be configured identically to that of the end effector 100, but the third layer 136 of the film is omitted so that the two flexible substrates 111, 151 may be provided on the spine 122 either directly or in contact with each other.
[0082] Figure 8 shows yet another modification 100.3 of the end effector 100 described above. In this example, the film 130 functions as a flexible circuit, and the first and second ablation electrodes 161A, 161B and the second and third ablation electrodes 161C, 161D are provided on its opposing surfaces.
[0083] Here, we refer to Figures 9-10, which show yet another modification 100.4 of the end effector 100 described above. In this example, the membrane 130.4 is configured to have voids 114.4 defined through it, each void 114.4 having a closed perimeter bounded by the membrane 130.4. The distal end 130-1.4 of the membrane 130.4 forms an annular bridge 131A.4 having a spine 122, and the electrode 160 is connected to the annular bridge 131A.4 via a connecting section 131B.4. The voids 114.4 allow for easier folding through the sheath and also allow for more blood flow. The volume of removed material is omitted (compared to the solid umbrella form), and therefore less material fits into a given folded cross section. The voids 114.4 may be configured in a size, shape, or otherwise such as to allow the end effector 100 to bend through the sheath catheter. The void 114.4 may be sized, molded, or otherwise configured to fold or expand when the end effector 100 is pressed against a non-planar tissue surface to provide conformal contact with the non-planar tissue surface. It is recognized that consistent contact of the ablation electrode 161 to the non-planar tissue can produce improved damage compared to less conformal electrode contact. The distal ends 130-1.4 of the membrane help maintain the relative positioning between the electrodes 160. The annular bridge 131A.4 (or additional bridges) may also be located along the membrane 130.4 at various distances from the longitudinal axis 60.
[0084] Here, we refer to Figures 11-12, which show yet another modification 100.5 of the end effector 100 described above. In this example, the spine 122.4 is configured in the form of a basket catheter, with a first end of the spine 122.4 connected to a first probe shaft 80, and a second end of the spine 122.4 connected to a second probe shaft 82 (e.g., a pusher tube or pusher wire) which can be used to expand and fold the basket (see the folded configuration in Figure 12, where the end effector 100.5 is positioned inside the sheath 90).
[0085] Figure 13 is a flowchart of a method 1000 for fabricating an end effector 100 according to the present disclosure. The method 1000 includes forming a plurality of spines extending away from the longitudinal axis (1002). The method 1000 includes arranging a first flexible circuit on a first side of the plurality of spines (1004), the first flexible circuit comprising a first flexible substrate and a first ablation electrode. The method 1000 includes arranging a second flexible circuit on a second side of the plurality of spines (1006), the second flexible circuit comprising a second flexible substrate and a second ablation electrode. The method 1000 includes arranging a first insulating material sheet in contact with the first flexible circuit (1008), the first sheet surrounding the longitudinal axis. Method 1000 includes positioning a second insulating material sheet in contact with a second flexible circuit (1010), such that the second sheet surrounds the longitudinal axis and defines a volume having an open end. The method also includes molding the first and second sheets to enclose the first and second flexible circuits, such that the first ablation electrode pair, the second ablation electrode pair, and one of the spines are positioned proximal to each other (1012).
[0086] In some embodiments, prior to forming the first and second sheets (1012), method 1000 further includes arranging a third insulating material sheet between the first and second flexible circuits in contact with the spines, and forming the third sheet such that the first and second flexible circuits are spaced apart from the spines.
[0087] Refer to Figures 14–17 here, which illustrate alternative / exemplary electrode configurations. In some examples, electrodes may have a fishbone configuration. An example of an electrode with a fishbone configuration is disclosed in U.S. Patent No. 11,642,165(B2), which is incorporated herein by reference in its entirety. Other advantageous designs are detailed below. Generally, each ablation electrode can be designed in shape based on a trade-off between total edge area, total contact area, and open space for the non-ablation electrode. It is recognized that a larger surface area-to-periphery ratio can effectively deliver ablation energy while reducing the opportunity for electrical arc discharge. It is also recognized that avoiding arc generation is desirable. Conversely, serpentine electrodes increase the mechanical flexibility of the paddle. While electrode flexibility can result in improved tissue contact and catheter life, it is recognized that the geometry of a serpentine electrode has a lower area-to-periphery ratio compared to a solid electrode.
[0088] Figure 14 is a diagram of a first electrode configuration of an exemplary end effector 100, including one exemplary configuration of therapeutic / ablation electrodes 161 and diagnostic electrodes 165. In the illustrated example, each ablation electrode 161 is divided into two longitudinally elongated segments extending along their associated spines 122. In this example, the longitudinally elongated segment to the left of the spine 122 forms the first ablation electrode 161, and the longitudinally elongated segment to the right of the spine 122 forms the second ablation electrode 161. As an example, in this configuration, the example in Figure 4A has a total of eight elongated segments (per associated spine 122), four on the upper side of the membrane 130 and four on the lower side. Naturally, it will be understood that in some embodiments, the aforementioned four electrodes 161A-161D each have a single elongated segment (per associated spine 122), so that there may be a total of four elongated segments. In some embodiments, the total area of each ablation electrode 161 or ablation electrode segment within each electrode region (as described above with respect to Figure 4A) is approximately 7.5 mm². 2In some embodiments, such as configurations like those in Figure 4A or 4B that implement the pairs of segments in Figure 11, one pair of these electrode segments in each electrode / spine region 102 may be connected together by a generator 50 having the same charge (e.g., positive charge), while another pair of these electrode segments in the same electrode / spine region 102 may be connected together by a generator 50 and have the same charge (e.g., negative charge), resulting in a biphasic pulsed field being provided between these two ablation electrode pair segments. In alternative examples, these adjacent elongated segments of each ablation electrode 161 (when in contact with tissue) may be separated from each other and connected separately to a generator 50, resulting in a biphasic pulsed field being provided between these two tissue-contact ablation electrode segments in a bipolar configuration, enabling the flow of electrons between the ablation electrode segments.
[0089] Generally, the ablation electrode 161 may include one or more meandering longitudinally extending segments having a total width W1 and a path width W2 (in the illustrated example of Figure 14, there are two, as described above). The example of Figure 14 includes six diagnostic electrodes 165 per ablation electrode 161. The end effector 100 may include one, two, three, four, five, or six diagnostic electrodes 165 per ablation electrode 161. Each diagnostic electrode is similarly sized to have a width W3 that is approximately 1.5 times the path width W2 of the ablation electrode 161 and approximately half the total width W1 of the elongated segment of the ablation electrode 161. The diagnostic electrode 165 is surrounded on two or three sides by each elongated segment of the ablation electrode 161.
[0090] Figure 15 shows a second electrode configuration of an exemplary end effector 100, which includes an ablation electrode 161 having elongated segments, each segmented into small parallel stripes, and a diagnostic electrode 165 positioned along the elongated ablation electrode segments. Each elongated segment has multiple conductive stripes extending parallel to each other to form the overall shape of each elongated segment, similar to that shown in Figure 14. Other ablation electrode shapes shown herein, and their alternatives as understood by those skilled in the art, can also be divided into multiple conductive stripes extending parallel to each other, similar to that shown in Figure 15. This configuration increases the total edge length of the ablation electrode, providing the tissue with a different electric field profile in the PFA than a similarly shaped solid ablation electrode (e.g., as shown in Figure 14).
[0091] Figure 16 shows a third exemplary electrode configuration of an exemplary end effector 100, which includes a rectangular elongated segment of an ablation electrode 161 without a diagnostic electrode 165. The total width W1 of the electrode segment is utilized for the ablation electrode 161 to maximize its surface area. The diagnostic electrode can be positioned elsewhere on the flexible membrane 130.
[0092] Figure 17 shows a fourth exemplary electrode configuration of an exemplary end effector 100, which includes a rectangular elongated segment of the ablation electrode 161 interrupted by the diagnostic electrode 165. Compared to the continuous rectangular electrode segment shown in Figure 16, the segmented elongated ablation electrode segment can have greater flexibility for the membrane 130 to bend, at the expense of the total area of the ablation electrode.
[0093] According to all of the examples described above, the end effector 100 preferably includes a total of 2 to 8 ablation electrodes 161 per associated spine 122. The end effector 100 preferably includes exactly 2, 3, or 4 ablation electrodes (or electrode segments) per side of the membrane 130. Each ablation electrode 161 preferably overlaps the corresponding ablation electrode 161 on the opposite side of the membrane 130 so that the ablation electrodes are symmetrical with respect to the plane defined by the membrane 130 when the ablation electrodes are laid flat (e.g., pre-assembled into their umbrella-shaped configuration). Fewer ablation electrodes can be achieved by electrically connecting combinations of ablation electrodes within the end effector 100 or other locations within the catheter 14. Increasing the number of ablation electrodes 161 can be achieved by dividing the ablation electrodes 161 into two parts configured to be electrically insulated from each other within the catheter 14 and to be operated independently by the generator 50. For example, the cross-sectional line 4A-4A in Figure 2A can function as a dividing line in an example where the ablation electrode 161A is segmented into two electrodes, namely the distal ablation electrode (the portion of 161A to the left of line 4A-4A in Figure 2A) and the proximal ablation electrode (the portion of 161A to the right of line 4A-4A in Figure 2A). Similarly, the ablation electrodes 161B, 161C, and 161D can be segmented in a similar manner.
[0094] In summary, the ablation electrodes 161 can be paired in various combinations to provide a bipolar PFA electrical signal between the paired therapeutic electrodes. As will be understood by those skilled in the art who are informed by the disclosure herein, the pairs can be operated simultaneously or sequentially in various combinations to achieve PFA of the target tissue. The exemplary therapeutic electrode configurations illustrated and described herein are not limiting, and a number of other therapeutic electrode configurations are possible. In each therapeutic electrode configuration, the therapeutic electrodes can be paired according to the same concepts as outlined in the preceding disclosure.
[0095] The technologies of this disclosure described herein can be further understood in accordance with the following provisions.
[0096] Clause 1. End effector of a medical probe, comprising a plurality of spines extending radially outward from the longitudinal axis of the end effector in an extended configuration, and a membrane connected to the plurality of spines, the membrane having a distal end that defines a volume surrounding the longitudinal axis and having an open end, the membrane comprising a first surface and a second surface opposite to the first surface, and a first flexible circuit positioned on the first surface of the membrane in close proximity to each of the plurality of spines and extending around the longitudinal axis, and the second surface of the membrane in close proximity to each of the plurality of spines An end effector comprising: a second flexible circuit positioned on top and extending around a longitudinal axis; a plurality of first electrode pairs positioned on the first flexible circuit relative to each other and proximal to spines among a plurality of spines; and a plurality of second electrode pairs positioned on the second flexible circuit relative to each other and proximal to spines among a plurality of spines, such that the first electrode pairs and the second electrode pairs define a mirror image configuration together with the film between the first electrode pairs and the second electrode pairs.
[0097] Clause 2. The end effector described in Clause 1, wherein multiple spines are arranged radially around the longitudinal axis.
[0098] Clause 3. The end effector according to Clause 1 or 2, wherein each spine comprises a proximal end fixed to the probe shaft and a free distal end, and the distal end of the membrane extends beyond the free distal end of each spine.
[0099] Clause 4. The end effector according to Clause 1 or 2, wherein each spine comprises a proximal end fixed to a first probe shaft and a distal end fixed to a second probe shaft.
[0100] Clause 5. An end effector as described in any one of Clauses 1 to 4, wherein the membrane is biased into an extended configuration by multiple spines.
[0101] Clause 6. The end effector according to any one of Clauses 1 to 5, wherein the membrane, in its extended configuration, includes a substantially hemispherical, semiconical, or polygonal pyramidal shape defining the volume, and further comprises a polymer material.
[0102] Clause 7. An end effector as described in any one of Clauses 1 to 6, wherein the end effector is movable between a folded configuration in which multiple spines and membranes are arranged substantially along the longitudinal axis and an extended configuration.
[0103] Clause 8. An end effector according to any one of Clauses 1 to 7, wherein the first surface faces away from the longitudinal axis and the second surface faces toward the longitudinal axis.
[0104] Clause 9. An end effector according to any one of Clauses 1 to 8, wherein the first flexible circuit and the second flexible circuit are spaced apart from a plurality of spines along a vertical axis, each first electrode pair is electrically connected to each other to define a single first electrode from a plurality of first electrodes on a first surface, and each second electrode pair is electrically connected to each other to define a single second electrode from a plurality of second electrodes on a second surface.
[0105] Clause 10. The end effector according to Clause 9, wherein a portion of the film is positioned between a plurality of spines and a first flexible circuit, and between a plurality of spines and a second flexible circuit.
[0106] Clause 11. An end effector according to any one of Clauses 1 to 10, further comprising a plurality of voids defined between adjacent spines of a plurality of spines through a film, a first flexible circuit, and a second flexible circuit.
[0107] Clause 12. Each void includes a closed periphery defined by the film, as described in Clause 11.
[0108] Clause 13. An end effector according to any one of Clauses 1 to 12, wherein the membrane comprises a flexible biocompatible polymer material.
[0109] Clause 14. The end effector according to any one of Clauses 1 to 13, wherein the film comprises multiple layers, each layer encircling a longitudinal axis, and at least one of the layers comprises an insulating material.
[0110] Clause 15. The end effector according to Clause 14, wherein each leaf has multiple layers, each including at least one layer containing a dielectric material.
[0111] Clause 16. An end effector according to any one of Clauses 1 to 15, wherein the first flexible circuit comprises a plurality of first flexible substrates spaced circumferentially around a longitudinal axis, and each first electrode is located on each of the first flexible substrates.
[0112] Clause 17. An end effector as described in any one of items 1 to 16, wherein the number of spines among multiple spines is greater than the number of the first electrode pair.
[0113] Clause 18. An end effector according to any one of Clauses 1 to 17, wherein each first pair of electrodes is coplanar with the outer surface of the film.
[0114] Clause 19. An end effector as described in any one of Clauses 1 to 17, wherein each first electrode pair protrudes from the outer surface of the film.
[0115] Clause 20. An end effector according to any one of Clauses 1 to 19, wherein the plurality of first electrode pairs and the plurality of second electrode pairs are ablation electrodes, and further comprises one or more diagnostic electrodes.
[0116] Clause 21. An end effector according to any one of Clauses 1 to 20, wherein each electrode of the first electrode pair and the second electrode pair includes an elongated segment, and the elongated segment includes a plurality of conductive stripes extending parallel to each other to form the overall shape of the elongated segment.
[0117] Clause 22. A medical probe comprising an elongated probe body and an end effector connected to the distal end of the elongated probe body, wherein the elongated probe body and the end effector extend along a longitudinal axis, and the end effector is connected to the elongated probe body and comprises a plurality of spines extending radially outward from the longitudinal axis of the end effector in an extended configuration, and a membrane connected to the plurality of spines, the membrane comprising a distal end that surrounds the longitudinal axis and defines a volume having an open end, the membrane comprising a first surface and a second surface opposite to the first surface, and a first flexible circuit positioned on the first surface of the membrane in close proximity to each of the plurality of spines and extending around the longitudinal axis, and a plurality of spines A medical probe comprising: a medical probe comprising: a second flexible circuit disposed on the second surface of a membrane in close proximity to each of the spines and extending around a longitudinal axis; a plurality of first ablation electrode pairs disposed on the first flexible circuit and proximal to each other and to the spines among a plurality of spines; a plurality of second electrode pairs, wherein the first electrode pairs and the second electrode pairs, having a membrane between them, define a mirror image configuration, and are disposed on the second flexible circuit, proximal to each other and to the spines among a plurality of spines; and an ablation generator configured to provide ablation pulses to the plurality of first electrode pairs and the plurality of second electrode pairs.
[0118] Clause 23. The medical system according to Clause 22, wherein a plurality of first ablation electrode pairs comprises a first ablation electrode and a second ablation electrode positioned proximal to each other, and a plurality of second ablation electrode pairs comprises a third ablation electrode and a fourth ablation electrode positioned proximal to each other, and one of the first ablation electrode pairs.
[0119] Clause 24. The medical system according to Clause 23, wherein each first pair of first ablation electrodes and second ablation electrodes are positioned on the side opposite to their respective spines, and each second pair of third ablation electrodes and fourth ablation electrodes are positioned on the side opposite to their respective spines.
[0120] Clause 25. The medical system according to Clause 23 or 24, wherein the ablation generator is configured to provide ablation pulses between the first ablation electrode and the fourth ablation electrode of each respective first electrode pair and second electrode pair.
[0121] Clause 26. The medical system according to Clause 23 or 24, wherein the ablation generator is configured to provide ablation pulses between the first ablation electrode and the third ablation electrode of each respective first electrode pair and second electrode pair.
[0122] Clause 27. The medical system according to Clause 23 or 24, wherein the ablation generator is configured to provide ablation pulses between the first ablation electrode and the second ablation electrode of each respective first electrode pair.
[0123] Clause 28. The medical system as described in Clause 23, wherein each set of proximal first, second, third, and fourth ablation electrodes defines its respective electrode and spine region, and the ablation generator is configured to provide ablation pulses between different electrode and spine regions.
[0124] Clause 28. A method for manufacturing an end effector for a medical probe, the method comprising: forming a plurality of spines extending away from the longitudinal axis; arranging a first flexible circuit on a first side of the plurality of spines, the first flexible circuit comprising a first flexible substrate and a first electrode pair; arranging a second flexible circuit on a second side of the plurality of spines, the second flexible circuit comprising a second flexible substrate and a second electrode pair; arranging a first insulating material sheet in contact with the first flexible circuit, the first sheet surrounding the longitudinal axis; arranging a second insulating material sheet in contact with the second flexible circuit, the second sheet surrounding the longitudinal axis and defining a volume having an open end; and molding the first sheet and the second sheet to enclose the first flexible circuit and the second flexible circuit.
[0125] Clause 29. The method according to Clause 28, further comprising: positioning a third insulating material sheet between the first flexible circuit and the second flexible circuit in contact with a plurality of spines before forming the first sheet and the second sheet; and forming the third sheet such that the first flexible circuit and the second flexible circuit are spaced apart from the plurality of spines.
[0126] The embodiments described above are cited as examples, and the technology of this disclosure is not limited to those specifically illustrated and described in the above specification. Rather, the scope of the technology of this disclosure includes both combinations and partial combinations of the various features described above, as well as variations and modifications thereof not disclosed in the prior art, which a person skilled in the art would conceive of by reading the above description.
[0127] Any material incorporated herein by reference may include similar terms, but to the extent that the definitions or descriptions differ, it will be understood that the definitions or descriptions provided herein are for use in understanding the technology disclosed herein.
[0128] [Implementation Method] (1) An end effector for a medical probe, wherein the end effector is In the extended configuration, multiple spines extend radially outward from the longitudinal axis of the end effector, A membrane connected to the plurality of spines, wherein the membrane has a distal end that defines a volume surrounding the longitudinal axis and having an open end, and the membrane includes a first surface and a second surface opposite to the first surface, A first flexible circuit is disposed on the first surface of the film in close proximity to each of the plurality of spines and extends around the longitudinal axis, A second flexible circuit is positioned on the second surface of the film in close proximity to each of the plurality of spines and extends around the longitudinal axis, On the first flexible circuit, there are a plurality of first electrode pairs arranged relative to each other and proximal to the spines among the plurality of spines, An end effector comprising a plurality of second electrode pairs, the second electrode pairs being positioned on the second flexible circuit, relative to each other and proximal to the spines among the plurality of spines, such that the first electrode pair and the second electrode pairs define a mirror image configuration together with the film between the first electrode pair and the second electrode pairs. (2) The end effector according to Embodiment 1, wherein the plurality of spines are arranged radially around the longitudinal axis. (3) The end effector according to Embodiment 1, wherein each spine comprises a proximal end fixed to the probe shaft and a free distal end, and the distal end of the membrane extends beyond the free distal end of each spine. (4) The end effector according to Embodiment 1, wherein each spine comprises a proximal end fixed to a first probe shaft and a distal end fixed to a second probe shaft. (5) The end effector according to Embodiment 1, wherein the film is biased to the extension configuration by the plurality of spines.
[0129] (6) The end effector according to Embodiment 1, wherein the film in the extended configuration includes a substantially hemispherical, semiconical, or polygonal pyramidal shape that defines the volume, and further comprises a polymer material. (7) The end effector according to Embodiment 1, wherein the end effector is movable between a folded configuration in which the plurality of spines and the film are arranged substantially along the longitudinal axis and an extended configuration. (8) The end effector according to Embodiment 1, wherein the first surface faces away from the longitudinal axis and the second surface faces toward the longitudinal axis. (9) The end effector according to Embodiment 1, wherein the first flexible circuit and the second flexible circuit are spaced apart from the plurality of spines along the vertical axis, each first electrode pair is electrically connected to each other to define a single first electrode from a plurality of first electrodes on the first surface, and each second electrode pair is electrically connected to each other to define a single second electrode from a plurality of second electrodes on the second surface. (10) The end effector according to Embodiment 9, wherein a portion of the film is positioned between the plurality of spines and the first flexible circuit, and between the plurality of spines and the second flexible circuit.
[0130] (11) The end effector according to Embodiment 1, further comprising a plurality of gaps defined between adjacent spines among the plurality of spines through the film, the first flexible circuit, and the second flexible circuit. (12) The end effector according to Embodiment 1, wherein the film comprises a plurality of layers, each layer surrounding the longitudinal axis, and at least one of the layers comprises an insulating material. (13) The end effector according to Embodiment 12, wherein each of the plurality of layers of a leaf includes at least one layer containing a dielectric material. (14) The end effector according to Embodiment 1, wherein the first flexible circuit comprises a plurality of first flexible substrates spaced circumferentially apart about the longitudinal axis, and each first electrode is disposed on each of the first flexible substrates. (15) The end effector according to Embodiment 1, wherein the number of spines among the plurality of spines is greater than the number of the first electrode pairs.
[0131] (16) The end effector according to Embodiment 1, wherein each first electrode pair is coplanar with the outer surface of the film. (17) The end effector according to Embodiment 1, wherein each first electrode pair protrudes from the outer surface of the film. (18) The end effector according to Embodiment 1, wherein each electrode of the first electrode pair and the second electrode pair includes an elongated segment, and the elongated segment includes a plurality of conductive stripes extending parallel to each other to form the overall shape of the elongated segment. (19) A medical system, A medical probe comprising an elongated probe body and an end effector connected to the distal end of the elongated probe body, wherein the elongated probe body and the end effector extend along their longitudinal axes, and the end effector is Connected to the elongated probe body, and in the extended configuration, a plurality of spines extending radially outward from the longitudinal axis of the end effector, A membrane connected to the plurality of spines, wherein the membrane has a distal end that defines a volume surrounding the longitudinal axis and having an open end, and the membrane includes a first surface and a second surface opposite to the first surface, A first flexible circuit is disposed on the first surface of the film in close proximity to each of the plurality of spines and extends around the longitudinal axis, A second flexible circuit is positioned on the second surface of the film in close proximity to each of the plurality of spines and extends around the longitudinal axis, On the first flexible circuit, a plurality of first ablation electrode pairs are arranged relative to each other and proximal to the spines among the plurality of spines, A medical probe comprising: a plurality of second electrode pairs, the second electrode pairs positioned on the second flexible circuit, relative to each other and proximal to the spines among the plurality of spines, such that the first electrode pair and the second electrode pairs define a mirror image configuration together with the film between the first electrode pair and the second electrode pair; A medical system comprising: an ablation generator configured to provide ablation pulses to a plurality of first electrode pairs and a plurality of second electrode pairs. (20) A method for manufacturing an end effector for a medical probe, wherein the method is Forming multiple spines that extend away from the longitudinal axis, The arrangement involves arranging a first flexible circuit on the first side of the plurality of spines, wherein the first flexible circuit comprises a first flexible substrate and a first electrode pair. The arrangement involves arranging a second flexible circuit on the second side of the plurality of spines, wherein the second flexible circuit comprises a second flexible substrate and a second electrode pair. The first insulating material sheet is placed in contact with the first flexible circuit, and the first sheet is placed so as to surround the longitudinal axis. The second insulating material sheet is placed in contact with the second flexible circuit, wherein the second sheet surrounds the longitudinal axis and defines a volume having an open end. A method comprising molding the first sheet and the second sheet so as to enclose the first flexible circuit and the second flexible circuit.
Claims
1. An end effector for a medical probe, wherein the end effector is In the extended configuration, multiple spines extend radially outward from the longitudinal axis of the end effector, A membrane connected to the plurality of spines, wherein the membrane has a distal end that defines a volume surrounding the longitudinal axis and having an open end, and the membrane includes a first surface and a second surface opposite to the first surface, A first flexible circuit is disposed on the first surface of the film in close proximity to each of the plurality of spines and extends around the longitudinal axis, A second flexible circuit is positioned on the second surface of the film in close proximity to each of the plurality of spines and extends around the longitudinal axis, On the first flexible circuit, there are a plurality of first electrode pairs arranged relative to each other and proximal to the spines among the plurality of spines, An end effector comprising a plurality of second electrode pairs, the second electrode pairs being positioned on the second flexible circuit, relative to each other and proximal to the spines among the plurality of spines, such that the first electrode pair and the second electrode pairs define a mirror image configuration together with the film between the first electrode pair and the second electrode pair.
2. The end effector according to claim 1, wherein the plurality of spines are arranged radially around the longitudinal axis.
3. The end effector according to claim 1, wherein each spine comprises a proximal end fixed to a probe shaft and a free distal end, and the distal end of the membrane extends beyond the free distal end of each spine.
4. The end effector according to claim 1, wherein each spine comprises a proximal end fixed to a first probe shaft and a distal end fixed to a second probe shaft.
5. The end effector according to claim 1, wherein the film is biased to the extended configuration by the plurality of spines.
6. The end effector according to claim 1, wherein the film in the extended configuration includes a substantially hemispherical, semiconical, or polygonal pyramidal shape that defines the volume, and further comprises a polymer material.
7. The end effector according to claim 1, wherein the end effector is movable between a folding configuration in which the plurality of spines and the film are arranged substantially along the longitudinal axis and an extended configuration.
8. The end effector according to claim 1, wherein the first surface faces away from the longitudinal axis, and the second surface faces toward the longitudinal axis.
9. The end effector according to claim 1, wherein the first flexible circuit and the second flexible circuit are spaced apart from the plurality of spines along a vertical axis, each first electrode pair is electrically connected to each other to define a single first electrode from a plurality of first electrodes on the first surface, and each second electrode pair is electrically connected to each other to define a single second electrode from a plurality of second electrodes on the second surface.
10. The end effector according to claim 9, wherein a portion of the film is disposed between the plurality of spines and the first flexible circuit, and between the plurality of spines and the second flexible circuit.
11. The end effector according to claim 1, further comprising a plurality of voids defined between adjacent spines among the plurality of spines, through the film, the first flexible circuit, and the second flexible circuit.
12. The end effector according to claim 1, wherein the film comprises a plurality of layers, each layer surrounding the longitudinal axis, and at least one of the layers comprises an insulating material.
13. The end effector according to claim 12, wherein each of the plurality of layers of a leaf includes at least one layer containing a dielectric material.
14. The end effector according to claim 1, wherein the first flexible circuit comprises a plurality of first flexible substrates spaced apart circumferentially around the longitudinal axis, and each first electrode is arranged on each of the first flexible substrates.
15. The end effector according to claim 1, wherein the number of spines among the plurality of spines is greater than the number of the first electrode pairs.
16. The end effector according to claim 1, wherein each first electrode pair is coplanar with the outer surface of the film.
17. The end effector according to claim 1, wherein each first electrode pair protrudes from the outer surface of the film.
18. The end effector according to claim 1, wherein each electrode of the first electrode pair and the second electrode pair includes an elongated segment, and the elongated segment includes a plurality of conductive stripes extending parallel to each other to form the overall shape of the elongated segment.
19. It is a medical system, A medical probe comprising an elongated probe body and an end effector connected to the distal end of the elongated probe body, wherein the elongated probe body and the end effector extend along their longitudinal axes, and the end effector is Connected to the elongated probe body, and in the extended configuration, a plurality of spines extending radially outward from the longitudinal axis of the end effector, A membrane connected to the plurality of spines, wherein the membrane has a distal end that defines a volume surrounding the longitudinal axis and having an open end, and the membrane includes a first surface and a second surface opposite to the first surface, A first flexible circuit is disposed on the first surface of the film in close proximity to each of the plurality of spines and extends around the longitudinal axis, A second flexible circuit is positioned on the second surface of the film in close proximity to each of the plurality of spines and extends around the longitudinal axis, On the first flexible circuit, a plurality of first ablation electrode pairs are arranged relative to each other and proximal to the spines among the plurality of spines, A medical probe comprising: a plurality of second electrode pairs, the second electrode pairs being positioned on the second flexible circuit, relative to each other and proximal to the spines among the plurality of spines, such that the first electrode pair and the second electrode pair define a mirror image configuration together with the film between the first electrode pair and the second electrode pair; A medical system comprising: an ablation generator configured to provide ablation pulses to a plurality of first electrode pairs and a plurality of second electrode pairs.
20. A method for manufacturing an end effector for a medical probe, wherein the method is Forming multiple spines that extend away from the longitudinal axis, The arrangement involves arranging a first flexible circuit on the first side of the plurality of spines, wherein the first flexible circuit comprises a first flexible substrate and a first electrode pair. The arrangement involves arranging a second flexible circuit on the second side of the plurality of spines, wherein the second flexible circuit comprises a second flexible substrate and a second electrode pair. The first insulating material sheet is placed in contact with the first flexible circuit, and the first sheet is arranged so as to surround the longitudinal axis. The second insulating material sheet is placed in contact with the second flexible circuit, wherein the second sheet surrounds the longitudinal axis and defines a volume having an open end. A method comprising molding the first sheet and the second sheet so as to enclose the first flexible circuit and the second flexible circuit.
