CN118922141A - Dual focus and linear Pulsed Field Ablation (PFA) catheter - Google Patents

Abstract

An example catheter for performing Pulsed Field Ablation (PFA) includes: an elongated structure defining a longitudinal axis; a plurality of electrodes carried on a distal portion of the elongate structure, the plurality of electrodes comprising: a tip electrode positioned at a distal tip of the elongated structure; a tip ring electrode adjacent to the tip electrode; a pair of ring electrodes; and one or more additional electrodes, wherein the pair of ring electrodes is disposed longitudinally along the elongated structure between the tip ring electrode and the one or more additional electrodes.

Description

Dual Focused and Linear Pulsed Field Ablation (PFA) Catheters

This application claims the benefit of U.S. Provisional Patent Application No. 63/326,482 filed on April 1, 2022 and U.S. Patent Application No. 18/183,527 filed on March 14, 2023, the entire contents of which are incorporated herein by reference.

Technical Field

The present technology relates to ablation catheters. In particular, various examples of the present technology relate to ablation catheters for performing pulsed field ablation (PFA).

Background Art

Tissue ablation is a medical procedure commonly used to treat conditions such as cardiac arrhythmias, which include atrial fibrillation. To treat cardiac arrhythmias, ablation may be performed to modify tissue in order to stop abnormal electrical propagation and/or interrupt abnormal electrical conduction through cardiac tissue. Although thermal ablation techniques such as cryoablation and radiofrequency (RF) ablation are often used, non-thermal techniques such as pulsed field ablation (PFA) may also be used.

Pulsed field ablation involves the application of short pulsed electric fields (PEFs) that can destabilize cell membranes reversibly or irreversibly through electroosmosis, but generally do not affect the structural integrity of tissue components, including acellular cardiac extracellular matrix. The properties of PFA allow for very short durations of therapeutic energy delivery, on the order of tens of milliseconds. In addition, PFA may not cause collateral damage to non-target tissues as frequently or severely as thermal ablation techniques.

Summary of the invention

The present technology relates to devices, systems and methods for performing pulsed field ablation (PFA) in multiple modes using a single catheter. PFA can be performed in multiple modes, including linear mode and focused mode. Linear mode PFA may result in a relatively uniform field geometry that is linear along the active portion of the catheter (e.g., the cathode and anode may alternate along the catheter). On the other hand, focused mode PFA may result in a field geometry that is focused at the tip of the catheter (e.g., the tip of the catheter may be the cathode, while the rest of the catheter may be the anode, or vice versa). Generally speaking, linear mode PFA may produce a lesion that is longer than the width, while focused mode PFA may produce a lesion that is wider than the length. In some examples, a practitioner who desires to use both linear mode PFA and focused mode PFA may have to physically switch between different catheters. For example, in order to switch from linear mode PFA to focused mode PFA, the surgeon may have to remove the linear mode catheter and insert the focused mode catheter. Having to physically switch the catheter when using different PFA modes may be undesirable.

According to one or more aspects of the present disclosure, a single catheter may be configured to perform PFA in both a linear mode and a focused mode. For example, the catheter may include multiple electrodes that are independently controllable and in sufficient number to perform both a linear mode and a focused mode. In order to operate the catheter in a focused mode, the controller may output energy to the electrodes of the catheter so that the electrodes produce a field having a geometry that is focused at the tip of the catheter. For example, the controller may cause one or more electrodes positioned proximal to the tip of the catheter to operate as cathodes, and cause multiple electrodes positioned further distal to the tip to operate as anodes. In order to operate the catheter in a linear mode, the controller may output energy to the electrodes of the catheter so that the electrodes produce a field having a geometry that is linearly relatively uniform along the active portion of the catheter. For example, the controller may cause the electrodes to form alternating cathodes and anodes.

Although the manufacture of a catheter capable of performing both linear PFA and focused PFA may be more complex and/or more expensive than a catheter capable of performing only one of linear PFA and focused PFA, the catheter of the present disclosure may provide several advantages. For example, the catheter of the present disclosure may enable a surgeon to switch between linear PFA and focused PFA without having to remove and reinsert the catheter.

In one example, a catheter for performing pulsed field ablation (PFA) includes: a slender structure defining a longitudinal axis; a plurality of electrodes carried on a distal portion of the slender structure, the plurality of electrodes including: a tip electrode positioned at the distal tip of the slender structure; a tip ring electrode adjacent to the tip electrode; a ring electrode pair; and one or more additional electrodes, wherein the ring electrode pair is longitudinally disposed along the slender structure between the tip ring electrode and the one or more additional electrodes.

In another example, a method for performing pulsed field ablation (PFA) includes: at a first time and by a controller connected to a specific catheter, determining to perform PFA using a linear PFA mode; in response to determining to use the linear PFA mode, by the controller and outputting energy to an electrode of the specific catheter so that the electrode generates a field having a geometry that is linear along an active portion of the specific catheter; at a second time and by the controller, determining to perform PFA using a focused PFA mode; in response to determining to use the focused PFA mode, by the controller and outputting energy to the electrode of the specific catheter so that the electrode generates a field having a geometry that is focused at the tip of the specific catheter.

The details of one or more aspects of the present disclosure are set forth in the following drawings and description. Other features, objectives, and advantages of the techniques described in the present disclosure will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a conceptual diagram illustrating an example system for delivering pulsed field ablation (PFA) according to one or more aspects of the present disclosure.

2A and 2B are conceptual diagrams illustrating example linear and focused operations of a catheter according to one or more aspects of the present disclosure.

2C and 2D are conceptual diagrams illustrating example fields produced by linear and focused operations of a catheter according to one or more aspects of the present disclosure.

3A and 3B are conceptual diagrams illustrating example linear and focused operations of a catheter according to one or more aspects of the present disclosure.

3C and 3D are conceptual diagrams illustrating example fields produced by linear and focused operations of a catheter according to one or more aspects of the present disclosure.

4 is a conceptual diagram illustrating an example focusing operation of a catheter according to one or more aspects of the present disclosure.

5 is a block diagram illustrating an example controller of a multi-mode PFA system according to one or more aspects of the present disclosure.

6 is a flow chart illustrating an example technique for performing both linear PFA and focused PFA using a single catheter in accordance with one or more aspects of the present disclosure.

DETAILED DESCRIPTION

FIG. 1 is a conceptual diagram illustrating an example system 100 for delivering pulsed field ablation (PFA) including a catheter 102 and a controller 104. In general, to deliver PFA, a medical practitioner (e.g., a cardiologist, a surgeon, etc.) may insert a catheter 102 into a patient and cause a controller 104 to deliver electroporation energy (e.g., pulsed field ablation energy) via the catheter 102. Electroporation may be a phenomenon that causes cell membranes to become "leaky" (i.e., permeable to molecules that may not be permeable or semi-permeable to the cell membrane). Electroporation, which may also be referred to as electroosmosis, pulsed electric field treatment, non-thermal irreversible electroporation, irreversible electroporation, high-frequency irreversible electroporation, nanosecond electroporation, or nanoelectroporation, involves applying high amplitude pulses to cause physiological modification (i.e., permeabilization) of cells of tissue to which energy is applied. These pulses can be short (e.g., nanosecond, microsecond, or millisecond pulse widths) to allow application of high voltage, high current (e.g., 20 amps or more) without long duration current flow that might otherwise result in significant tissue heating and muscle stimulation. The pulsed electrical energy can induce the formation of microscopic defects, leading to hyperpermeabilization of the cell membrane. Depending on the characteristics of the electrical pulse, the electroporated cells can survive (referred to as "reversible electroporation") or die (referred to as "irreversible electroporation" (IRE)) after electroporation. Reversible electroporation can be used to transfer reagents (including genetic material and other macromolecules or small molecules) into target cells for various purposes, including altering the action potential of cardiomyocytes.

The catheter 102 may include an elongated structure 112 carrying a plurality of electrodes 110A-110H (collectively referred to as "electrodes 110"). The catheter 102 may generally include features that enable the catheter 102 to be inserted into a patient and to enable the catheter 102 to be navigated to a target treatment site. The elongated structure 112 may include a distal portion 106 and a proximal portion 108. The electrode 110 may generally be positioned at the distal portion 106, while the proximal portion 108 may be connected to the controller 104. The electrode 110 may have any suitable geometry. Example geometries of the electrode include, but are not necessarily limited to, a circular (e.g., annular) electrode surrounding the body of the lead, a conformable electrode, a hoop-shaped electrode, a segmented electrode (e.g., an electrode disposed at different circumferential positions around the lead, rather than a continuous annular electrode), and any combination thereof (e.g., annular electrodes and segmented electrodes). The electrodes 110 may be distributed axially along the longitudinal axis LA of the elongated structure 112.

The elongated structure 112 may include a conductor configured to carry an electrical signal between the electrode 110 and the controller 104. In some examples, the elongated structure 112 may include a separate conductor (e.g., a separate control lead) for each electrode in the electrode 110. For example, in the example of FIG. 1 in which the electrode 110 includes eight electrodes, the elongated structure 112 may include eight separate conductors. In this way, the elongated structure may enable each electrode in the electrode 110 to be driven with a different signal. In other examples, a plurality of electrodes in the electrode 110 may share a common conductor. For example, electrodes 110C and 110D may be connected to the same (e.g., common) conductor. Although such a common conductor arrangement may reduce flexibility (e.g., because the electrodes connected to the common conductor may be driven with the same signal), such an arrangement may reduce the complexity and/or cost of manufacturing. Generally speaking, a conductor may be referred to as a control lead.

As shown in FIG. 1 , the electrode 110 may include a tip electrode (e.g., electrode 110A), which may be a ring electrode having a "cap" covering at least a portion of the tip of the elongated structure 112. In some examples, the tip electrode may be beveled or otherwise rounded (e.g., to enable the catheter 102 to more easily pass through the patient's anatomical structure). The electrode 110 may include a tip ring electrode (e.g., electrode 110B) adjacent to the tip electrode. The tip ring electrode may be separated from the tip electrode (axially along the LA). The electrode 110 may include one or more ring electrode pairs. The ring electrode pair may include two adjacent closely spaced electrodes in the electrode 110. For example, in the example of FIG. 1 , electrodes 110C and 110D may form a first ring electrode pair, electrodes 110E and 110F may form a second ring electrode pair, and electrodes 110G and 110H may form a third ring electrode pair. Generally speaking, the first ring electrode pair (i.e., electrodes 110C and 110D) may be accompanied by one or more additional electrodes. The one or more additional electrodes may include any combination of ring electrode pairs and coil electrodes (e.g., electrodes including a conductor spirally wrapped around elongated structure 112). Thus, electrode 110 may include tip electrode 110A, tip ring electrode 110B (e.g., adjacent to tip electrode 110A), electrodes 110C and 110D (e.g., a ring electrode pair), and one or more additional electrodes (e.g., ring electrode pairs 110E and 110F and ring electrode pairs 110G and 110H).

1 , electrodes 110 are illustrated as having a larger diameter than elongated structure 112. In some examples, one or more of electrodes 110 may have a diameter that is substantially equal to the diameter of elongated structure 112. For example, electrode 110 may be recessed within elongated structure 112 such that the combination produces a relatively smooth outer surface.

The controller 104 may include an energy generator configured to provide electrical pulses to the electrode 110 to perform an electroporation procedure on cardiac tissue or other tissue in the patient's body (such as kidney tissue, airway tissue, and organs or tissues within the cardiac space or pericardial space). For example, the energy generator may be configured and programmed to deliver a pulsed high voltage electric field suitable for achieving the desired pulse, high voltage ablation (referred to as "pulsed field ablation" or "pulsed electric field ablation") and/or pulsed radiofrequency ablation. As a reference point, the non-radio frequency pulsed high voltage ablation effect of the present disclosure can be distinguished from DC current ablation and thermally induced ablation accompanying conventional RF technology. For example, the pulse train delivered by the energy generator can be delivered at a frequency of less than 30kHz, and in an exemplary configuration, at a frequency of 1kHz (lower than the frequency of radiofrequency treatment). The pulsed field energy according to the present disclosure may be sufficient to induce cell death so as to completely block abnormal conduction pathways along or through cardiac tissue, thereby destroying the ability of the cardiac tissue so ablated to propagate or conduct cardiac depolarization waveforms and associated electrical signals. Additionally or alternatively, the energy generator may be configured and programmed to deliver RF energy suitable for achieving tissue ablation.

According to one or more aspects of the present disclosure, the catheter 102 may be configured to selectively perform PFA using a linear mode or a focused mode. For example, the electrodes 110 of the catheter 102 may include both electrodes configured to deliver PFA using a linear mode and electrodes configured to deliver PFA using a focused mode (for different modes, there may be some or all overlap between the electrodes). By enabling a single catheter to perform both linear mode PFA and focused mode PFA, the present disclosure provides several advantages. As an example, a practitioner can switch between linear lesion formation and focused lesion formation without having to remove the catheter. As another example, supply management can be simplified (e.g., because the number of catheter types can be reduced).

During the ablation procedure, the practitioner may desire to switch between linear lesion formation and focused lesion formation. To achieve such switching, the controller 104 may be configured to selectively operate the catheter 102 in a linear mode and a focused mode. The practitioner may adjust the setting of the controller 104 to a linear mode or a focused mode. The controller 104 may operate the catheter 102 in the selected mode. For example, in order to operate the catheter 102 in the focused mode, the controller 104 may output energy to the electrode 110 so that the electrode 110 generates a field having a geometry focused at the tip of the catheter 102 (e.g., focused at the tip electrode 110A). Such a focused field geometry may result in the formation of a lesion proximal to the tip of the catheter 102. In order to operate the catheter 1002 in the linear mode, the controller 104 may output energy to the electrode 110 so that the electrode 110 generates a field having a relatively uniform geometry that is linear along the active portion of the catheter 102 (e.g., along a portion of the catheter 102 on which the electrode 110 is positioned). Such a linear field geometry may result in the formation of lesions longitudinally along the active portion of the catheter 102 .

As discussed above, in order to operate the catheter 102 in a focused mode, the controller 104 may output energy to the electrode 110 so that the electrode 110 generates a field having a geometry focused at the tip of the catheter 102. For example, the controller 104 may cause one or more electrodes positioned proximal to the tip of the catheter 102 (e.g., the tip electrode 110A and the tip ring electrode 110B) to operate as cathodes, and cause multiple electrodes positioned further distal to the tip (e.g., ring electrodes 110C and 110D) to operate as anodes. In some examples, one or more of the cathode and/or anode may be formed by a single electrode. In some examples, one or more of the cathode and/or anode may be formed by multiple electrodes. For example, the electrodes of the ring electrode pair may be driven with the same signal so that the electrodes of the ring electrode pair act as a single cathode or a single anode.

In some examples, to facilitate functioning as a single anode or a single cathode, the electrodes of the ring electrode pair may be positioned closer to each other than to adjacent electrodes. For example, the distance between the electrodes of the first ring electrode pair (e.g., the distance along LA between electrodes 110C and 110D) may be smaller than the distance between the distal ring electrode and the tip ring electrode of the ring electrode pair (e.g., the distance along LA between electrodes 110C and 110B).

The distances between adjacent ring electrode pairs may be substantially equal. For example, the distance between a first ring electrode pair (e.g., ring electrodes 110C and 110D) and a second ring electrode pair (e.g., ring electrodes 110E and 110F) may be substantially equal to the distance between the second ring electrode pair and a third ring electrode pair (e.g., ring electrodes 110G and 110H). Thus, in some examples, the ring electrode pairs in electrode 110 may be considered to be equally spaced along the LA of catheter 102.

Although not shown, the system 100 may include one or more sensors for monitoring operating parameters (such as temperature, delivered voltage, etc.) by the medical system 100, and for measuring and monitoring one or more tissue characteristics (such as EGM waveforms, monophasic action potentials, tissue impedance, etc.), in addition to monitoring, recording, or otherwise transmitting measurements or conditions of the surrounding environment within the energy delivery device or other components of the system 100 or at a distal portion of the energy delivery device. The sensors may communicate with the controller 104 to initiate or trigger one or more alarms or ablation energy delivery modifications during operation of the energy delivery device.

2A and 2B are conceptual diagrams illustrating example linear and focused operations of a catheter according to one or more aspects of the present disclosure. FIGS. 2C and 2D are conceptual diagrams illustrating example fields produced by linear and focused operations of a catheter according to one or more aspects of the present disclosure. The catheter 202 of FIGS. 2A and 2B may be an example of the catheter 102 of FIG. 1 .

FIG. 2A illustrates an example of how a controller (such as controller 104) may operate catheter 202 in a linear PFA mode. As shown in FIG. 2A , to operate catheter 302 in a linear PFA mode, the controller may drive electrode 210A (e.g., tip electrode) and electrode 210B (e.g., tip ring electrode) at a first polarity (e.g., as a cathode in the example of FIG. 2A ). The controller may drive electrodes 210C and 210D (e.g., a first ring electrode pair) at a second polarity different from the first polarity (e.g., as an anode in the example of FIG. 2A ). The controller may drive electrodes 210E and 210F (e.g., a second ring electrode pair) at a first polarity, and drive electrodes 210G and 210H (e.g., a third ring electrode pair) at a second polarity. By driving electrodes 210 (electrode pairs 210) at alternating polarities, the controller may achieve a substantially linear field along the axial direction of catheter 202 as shown in FIG. 2C . Generally speaking, driving the electrodes may include delivering energy to the electrodes. For example, to drive the electrodes 210 with alternating polarities, the controller 104 may deliver energy to the electrode pairs 210 with alternating polarities.

Generally speaking, the electrodes of a ring-shaped electrode pair may be closer together than the electrodes of an adjacent electrode pair. For example, the distance between electrode 210C and electrode 210D may be smaller than the distance between electrode 210D and electrode 210E.

FIG2B illustrates an example of how a controller (such as controller 104) may operate catheter 202 in focused PFA mode. As shown in FIG2B , to operate catheter 302 in focused PFA mode, the controller may drive electrode 210A (e.g., tip electrode) and electrode 210B (e.g., tip ring electrode) at a first polarity (e.g., as cathodes in the example of FIG2A ). The controller may drive electrodes 210C and 210D (e.g., first ring electrode pair) at a second polarity different from the first polarity (e.g., as anodes in the example of FIG2A ). The controller may drive electrodes 210E and 210F (e.g., second ring electrode pair) at a second polarity, and drive electrodes 210G and 210H (e.g., third ring electrode pair) at a second polarity. By driving electrodes of electrode 210 near the tip at a first polarity and driving other electrodes of electrode 210 at a second polarity, the controller may achieve a substantially focused field at the tip of catheter 202 as shown in FIG2D .

3A and 3B are conceptual diagrams illustrating example linear and focused operations of a catheter according to one or more aspects of the present disclosure. FIGS. 3C and 3D are conceptual diagrams illustrating example fields produced by linear and focused operations of a catheter according to one or more aspects of the present disclosure. The catheter 302 of FIGS. 3A and 3B may be an example of the catheter 102 of FIG. 1 .

FIG3A illustrates an example of how a controller (such as controller 104) may operate catheter 302 in linear PFA mode. As shown in FIG3A , to operate catheter 302 in linear PFA mode, the controller may drive electrode 310A (e.g., tip electrode) and electrode 310B (e.g., tip ring electrode) at a first polarity (e.g., as cathodes in the example of FIG3A ). The controller may drive electrodes 310C and 310D (e.g., first ring electrode pair) at a second polarity different from the first polarity (e.g., as anodes in the example of FIG3A ). In linear mode, the controller may not drive electrode 310E (e.g., coil electrode). For example, the controller may float electrode 310E. By driving electrodes 310 in this manner, the controller may achieve a substantially linear field along the axial direction of catheter 302 as shown in FIG3C . Thus, the electrode 310 may include a tip electrode 310A, a tip ring electrode 310B (eg, adjacent to the tip electrode 310A), electrodes 310C and 310D (eg, a pair of ring electrodes), and one or more additional electrodes (eg, a coil electrode 310E).

As described above, the electrode (e.g., electrode 310E) may be a coil electrode. The coil may take the form of a wound coil, or alternatively, as a spiral laser cut tube that is flexible like a coil but has a larger surface area. The number of windings may be adjusted to reduce or increase the surface area of the end ends or middle portion of the coil. In one example, the surface area at the distal end of the coil may be reduced (wider spaced coil windings). In this way, aspects of the present invention may limit the electric field distribution around the end regions of the coil. In some examples, this may be an example of a short linear pattern.

FIG3B illustrates an example of how a controller (such as controller 104) may operate catheter 302 in focused PFA mode. As shown in FIG3B , to operate catheter 302 in focused PFA mode, the controller may drive electrode 210A (e.g., tip electrode) and electrode 210B (e.g., tip ring electrode) at a first polarity (e.g., as cathodes in the example of FIG2A ). The controller may drive electrodes 210C and 210D (e.g., first ring electrode pair) at a second polarity different from the first polarity (e.g., as anodes in the example of FIG2A ). The controller may drive electrode 210E (e.g., coil electrode) at a second polarity. By driving electrodes 310 in this manner, the controller may achieve a substantially focused field at the tip of catheter 302 as shown in FIG3D .

FIG. 4 is a conceptual diagram illustrating an example focusing operation of a catheter according to one or more aspects of the present disclosure. In particular, FIG. 4 illustrates an example of how a controller (such as controller 104) may operate a catheter 402 in a linear PFA mode. As shown in FIG. 4 , to operate the catheter 402 in a linear PFA mode, the controller may drive an electrode 410A (e.g., a tip electrode) and an electrode 410B (e.g., a tip ring electrode) at a first polarity (e.g., as a cathode in the example of FIG. 4 ). The controller may float electrodes 310C and 310D (e.g., a first ring electrode pair) and drive electrode 410E (e.g., a coil electrode) at a second polarity different from the first polarity (e.g., as an anode in the example of FIG. 4 ). By driving the electrodes 410 in this manner, the controller may produce a more focused focusing mode in which ablation occurs closer to the two tip electrodes 410A and 410B. In some examples, this may be an example of a long linear mode.

FIG5 is a block diagram illustrating an example controller of a multi-mode PFA system according to one or more aspects of the present disclosure. The controller 504 of FIG5 may be an example of the controller 104 of FIG1 . As shown in FIG5 , the controller 504 may include an energy generator 516 , a processing circuit 518 , a user interface 520 , and a storage device 522 .

The energy generator 516 may be configured to provide electrical pulses to an electrode (e.g., electrode 110 of FIG. 1 ) to perform an electroporation procedure on cardiac tissue or other tissue in a patient's body (such as kidney tissue, airway tissue, and organs or tissues within the cardiac space or pericardial space). For example, the energy generator 516 may be configured and programmed to deliver a pulsed high voltage electric field suitable for achieving desired pulses, high voltage ablation (referred to as "pulsed field ablation" or "pulsed electric field ablation") and/or pulsed radiofrequency ablation. Although shown as a single energy generator in the example of FIG. 5 , the energy generator 516 is not limited thereto. For example, the controller 504 may include multiple energy generators, each of which is capable of generating ablation signals in parallel.

The processing circuit 518 may include one or more processors, such as one or more of the following: a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a discrete logic circuit, or any other processing circuit configured to provide the functionality attributed to the processing circuit 518, which may be embodied herein as firmware, hardware, software, or any combination thereof. The processing circuit 518 controls the energy generator 516 to generate signals according to various settings, such as a linear setting 530 or a focus setting 532. In some examples, the processing circuit 518 may execute other instructions stored in the storage device 522 to perform PFA according to the linear setting 530 or the focus setting 532.

The storage device 522 may be configured to store information during operation, respectively, within the controller 504. The storage device 522 may include a computer-readable storage medium or a computer-readable storage device. In some examples, the storage device 522 includes one or more of a short-term memory or a long-term memory. The storage device 522 may include, for example, a random access memory (RAM), a dynamic random access memory (DRAM), a static random access memory (SRAM), a magnetic disk, an optical disk, a flash memory, or various forms of electrically programmable memory (EPROM) or electrically erasable programmable memory (EEPROM). In some examples, the storage device 522 is used to store data indicating instructions executed, for example, by the processing circuit 518. As described above, the storage device 522 is configured to store the linear setting 430 and the focus setting 532.

The user interface 520 may include buttons or a keypad, lights, a speaker for voice commands, a display such as a liquid crystal (LCD), a light emitting diode (LED), or an organic light emitting diode (OLED). In some examples, the display includes a touch screen. The user interface 520 may be configured to display any information related to the execution of PFA. The user interface 520 may also receive user input (e.g., selection of a linear PFA mode or a focused PFA mode) via the user interface 520. The user input may be in the form of, for example, pressing a button on a keypad or selecting an icon from a touch screen.

6 is a flow chart illustrating an example technique for performing both linear PFA and focused PFA using a single catheter in accordance with one or more aspects of the present disclosure. The technique of FIG. 6 may be performed by a controller, such as controller 104 of FIG. 1 or controller 504 of FIG. 5 .

The controller 504 may receive a PFA model selection (602). For example, the processing circuit 518 of the controller 504 may receive a selection from a medical practitioner via the user input device 520 whether to operate in a focus mode or a linear mode.

Controller 504 may determine whether a linear mode is selected (604). In response to determining that a linear PFA mode is used (e.g., the "yes" branch of 604), controller 504 may drive the electrodes of the catheter to generate a linear field (606). For example, processing circuit 514 may cause energy generator 516 to output energy to the electrodes of the catheter so that the electrodes generate a field having a geometry that is linear along the active portion of the particular catheter (e.g., similar to the fields shown in FIGS. 2C and 3C).

Controller 504 may determine whether a focused mode is selected (608). In response to determining that a focused PFA mode is used (e.g., the "yes" branch of 608), controller 504 may drive the electrodes of the catheter to generate a focused field (610). For example, processing circuit 514 may cause energy generator 516 to output energy to the electrodes of the catheter so that the electrodes generate a field having a geometry that is focused at the tip of the particular catheter (e.g., similar to the fields shown in FIGS. 2D and 3D).

The following numbered embodiments may illustrate one or more aspects of the present disclosure:

Embodiment 1. A catheter for performing pulsed field ablation (PFA), the catheter comprising: a slender structure, the slender structure defining a longitudinal axis; a plurality of electrodes, the plurality of electrodes being carried on a distal portion of the slender structure, the plurality of electrodes comprising: a tip electrode, the tip electrode being positioned at the distal tip of the slender structure; a tip ring electrode, the tip ring electrode being adjacent to the tip electrode; a ring electrode pair; and one or more additional electrodes, wherein the ring electrode pair is longitudinally arranged along the slender structure between the tip ring electrode and the one or more additional electrodes.

Example 2. The catheter according to Example 1, wherein the distance between the electrodes of the ring electrode pair is smaller than the distance between the distal ring electrode and the tip ring electrode of the ring electrode pair.

Embodiment 3. The catheter according to embodiment 1 or embodiment 2 further comprises: a first common control lead connected to the tip electrode and the tip ring electrode.

Embodiment 4. The catheter according to any one of embodiments 1 to 3, further comprising: a second common control lead connected to two electrodes of the annular electrode pair.

Example 5. The catheter according to Example 1 or Example 2 further comprises: a separate control lead for each electrode of the plurality of electrodes.

Example 6. The catheter of any one of Examples 1 to 5, wherein the one or more additional electrodes comprises a coil electrode.

Embodiment 7. The catheter of any one of Embodiments 1 to 6, wherein the one or more additional electrodes comprise one or more additional annular electrode pairs.

Example 8. A catheter according to any one of Examples 1 to 5, wherein the one or more additional electrodes include: a coil electrode; and one or more additional annular electrode pairs, wherein the one or more additional annular electrode pairs are longitudinally arranged between the coil electrode and the annular electrode pair along the slender structure.

The techniques described in the present disclosure may be implemented at least in part in hardware, software, firmware, or any combination thereof. For example, various aspects of the described techniques may be implemented within a processing circuit that may include one or more processors, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs); or any other equivalent integrated or discrete logic circuits; and any combination of such components. The term "processor" or "processing circuit" may generally refer to any of the foregoing logic circuits, alone or in combination with other logic circuits, or any other equivalent circuits. A control unit including hardware may also form one or more processors or processing circuits configured to perform one or more techniques of the present disclosure.

Such hardware, software, and firmware may be implemented, and various operations may be performed on a coordinated basis within the same device, within a separate device, and/or within, between, or across multiple devices to support the various operations and functions described in this disclosure. In addition, any of the described units, circuits, or components may be implemented together, or individually as discrete but interoperable logic devices. Describing different features as circuits or units is intended to highlight different functional aspects, and does not necessarily imply that such circuits or units must be implemented by separate hardware components or software components. On the contrary, the functions associated with one or more circuits or units may be performed by separate hardware components or software components, or integrated in common or separate hardware components or software components. The processing circuits described in this disclosure, including one or more processors, may be implemented as fixed-function circuits, programmable circuits, or combinations thereof in various examples. Fixed-function circuits refer to circuits that provide specific functionality using preset operations. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functionality in executable operations. For example, a programmable circuit may execute software or firmware that causes the programmable circuit to operate in a manner defined by the instructions of the software or firmware. Fixed-function circuits can execute software instructions (e.g., to receive stimulation parameters or output stimulation parameters), but the type of operation performed by the fixed-function circuits is generally immutable. In some examples, one or more of these units can be different circuit blocks (fixed-function or programmable), and in some examples, one or more of these units can be integrated circuits.

The technology described in the present disclosure may also be embodied or encoded in a computer-readable medium (such as a computer-readable storage medium) containing instructions, which may be described as a non-transitory medium. The instructions embedded or encoded in the computer-readable storage medium may cause a programmable processor or other processor to perform the method, for example, when executing these instructions. The computer-readable storage medium may include a random access memory (RAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette, a magnetic medium, an optical medium, or other computer-readable medium. It should also be understood that when an electrode is described as an anode or a cathode, this does not mean that a direct current is delivered, but generally speaking, the present disclosure uses such terms to indicate that when an alternating current or the most common biphasic pulse waveform is delivered, the electrode referred to as the anode is connected to the opposite polarity of the electrode referred to as the cathode. Such a biphasic waveform may be delivered as a series of pulses (pulse train) consisting of a positive square wave pulse followed by a negative square wave pulse, wherein such a pulse train may consist of tens or hundreds of such alternating polarity (biphasic) pulses.

Claims (15)

1. A catheter for performing pulsed field ablation (PFA), the catheter comprising: an elongated structure defining a longitudinal axis; a plurality of electrodes carried on a distal portion of the elongated structure, the plurality of electrodes comprising: a tip electrode positioned at a distal tip of the elongated structure; a tip ring electrode, the tip ring electrode being adjacent to the tip electrode; a ring electrode pair; and One or more additional electrodes, wherein the ring electrode pair is disposed longitudinally along the elongated structure between the tip ring electrode and the one or more additional electrodes. 2 . The catheter according to claim 1 , wherein a distance between electrodes of the ring electrode pair is smaller than a distance between a distal ring electrode and the tip ring electrode of the ring electrode pair. 3. The catheter according to claim 1 or claim 2, further comprising: A first common control lead is connected to the tip electrode and the tip ring electrode. 4. The catheter according to any one of claims 1 to 3, further comprising: A second common control lead is connected to two electrodes of the annular electrode pair. 5. The catheter according to any one of claims 1 to 4, further comprising: A separate control lead is provided for each electrode in the plurality of electrodes. 6. The catheter of any one of claims 1 to 5, wherein the one or more additional electrodes comprise a coil electrode. 7. The catheter of any one of claims 1 to 6, wherein the one or more additional electrodes comprise one or more additional ring electrode pairs. 8. The catheter of any one of claims 1 to 5, wherein the one or more additional electrodes comprise: Coil electrodes; and One or more additional ring electrode pairs are disposed longitudinally along the elongated structure between the coil electrode and the ring electrode pairs. 9. A system, comprising: A catheter for performing pulsed field ablation (PFA), the catheter comprising: an elongated structure defining a longitudinal axis; a plurality of electrodes carried on a distal portion of the elongated structure, the plurality of electrodes comprising: a tip electrode positioned at a distal tip of the elongated structure; a tip ring electrode, the tip ring electrode being adjacent to the tip electrode; a ring electrode pair; and One or more additional electrodes, wherein the ring electrode pair is disposed longitudinally along the elongated structure between the tip ring electrode and the one or more additional electrodes. 10. The system according to claim 9, further comprising: A controller is configured to control the delivery of electrical stimulation via the catheter to perform PFA. 11. A catheter for performing pulsed field ablation (PFA), the catheter comprising: an elongated structure defining a longitudinal axis; a plurality of electrodes carried on a distal portion of the elongated structure, the plurality of electrodes comprising: a tip electrode positioned at a distal tip of the elongated structure; a tip ring electrode, the tip ring electrode being adjacent to the tip electrode; a ring electrode pair; and one or more additional electrodes, wherein the ring electrode pair is disposed longitudinally along the elongated structure between the tip ring electrode and the one or more additional electrodes; a plurality of control leads extending through the elongated structure, the plurality of control leads comprising: a first common control lead connected to the tip electrode and the tip ring electrode; and A second common control lead is connected to two electrodes of the annular electrode pair. 12. The catheter of claim 11, wherein the plurality of control leads further comprises: A separate control lead is provided for each electrode in the plurality of electrodes. 13. The catheter of claim 11 or claim 12, wherein the tip ring electrode is axially separated from the tip electrode along the longitudinal axis. 14. The catheter of any one of claims 11 to 13, wherein the outer diameter of the annular electrode pair is the same as the outer diameter of the distal portion of the elongated structure. 15. A catheter according to any one of claims 11 to 14, wherein the annular electrode pair includes a first annular electrode pair, wherein the one or more additional electrodes include a second annular electrode pair, and wherein the distance between the electrodes of the first annular electrode pair is less than the distance between adjacent electrodes of the first annular electrode pair and the second annular electrode pair.