Detection of ablation catheter failure

Abstract

An example method for assessing catheter integrity, the method comprising: outputting, by a device, a pulse of electrical energy onto a first conductor of a plurality of conductors of a catheter for performing irreversible electroporation (IRE) on a target tissue of a patient; measuring, by the device, a reflected electrical energy signal generated by the electrical energy pulse at the first conductor; determining, by the device, health statistics of the catheter based on the measured reflected electrical energy signal; and outputting, by the device, a representation of the statistics.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 384,903, filed Nov. 23, 2022, the entire content of which is incorporated herein by reference. Technical Field

[0002] The present technology relates to ablation catheters. Specifically, various examples of the present technology relate to the detection of faults in ablation catheters. Background Art

[0003] Tissue ablation is a medical procedure commonly used to treat conditions such as cardiac arrhythmias, which include atrial fibrillation. To treat cardiac arrhythmias, ablation can be performed to modify tissue in order to stop abnormal electrical propagation and / or interrupt abnormal electrical conduction through cardiac tissue. Ablation techniques include irreversible electroporation (IRE), cryoablation, laser ablation, thermal ablation, radiation ablation, and radiofrequency (RF) ablation.

[0004] Cardiac arrhythmias are a group of conditions that cause an irregular heartbeat or conduction pattern. Ablation can be used to create a safe and effective lesion or group of lesions at the origin of the arrhythmia or in an area that helps terminate the cardiac arrhythmia without causing damage to adjacent structures or surrounding tissue, ideally resulting in the need for no maintenance treatment regimens, such as medications or cardioversion. Summary of the Invention

[0005] The present technology relates to devices, systems, and methods for detecting faults in ablation catheters. Irreversible electroporation (IRE), such as pulsed field ablation (PFA), is an ablation therapy that irreversibly electroporates cardiac tissue by applying a pulsed electric field, where energy is delivered via a PFA ablation catheter. The energy used to create a transmural lesion can exceed 1500 V. As such, a defect or fault in the conductor or insulation of a PFA ablation catheter or associated cable, or a connectivity fault between system components, can result in an undesired event during the delivery of ablation therapy (e.g., sub-optimal therapy) via the PFA ablation catheter.

[0006] According to one or more aspects of the present disclosure, a device can perform one or more operations to automatically detect faults in a PFA ablation catheter. For example, the device can output a signal onto a conductor of the PFA ablation catheter and measure the reflected signal generated by the output signal. The device can detect faults in the PFA ablation catheter based on the reflected signal (e.g., using a time domain reflectometer). For example, an artifact in the reflected signal can indicate a fault (e.g., an open circuit) in the conductor when a change in impedance causes a change in a small portion of the reflected signal. In this way, the device can detect faults in the PFA ablation catheter.

[0007] In one example, a method for assessing catheter integrity includes: outputting, by a device, an electrical energy pulse to a first conductor of a plurality of conductors of a catheter for performing PFA on a target tissue of a patient; measuring, by the device, a reflected electrical energy signal generated by the electrical energy pulse at the first conductor; determining, by the device, a health statistic of the catheter based on the measured reflected electrical energy signal; and outputting, by the device, a representation of the statistic.

[0008] In another example, a device includes: a memory; a signal generator; and a processing circuit configured to cause the signal generator to output an electrical energy pulse to a first conductor of a plurality of conductors of a catheter for performing PFA on a target tissue of a patient; receive, at the first conductor, a reflected electrical energy signal generated by the electrical energy pulse; determine, by the device, a health statistic of the catheter based on the received reflected electrical energy signal; and output a representation of the statistic.

[0009] In another example, a non-transitory computer-readable storage medium stores instructions that, when executed, cause a processing circuit to cause the signal generator to output an electrical energy pulse to a first conductor of a plurality of conductors of a catheter for performing PFA on a target tissue of a patient; receive, at the first conductor, a reflected electrical energy signal generated by the electrical energy pulse; determine, by the device, a health statistic of the catheter based on the received reflected electrical energy signal; and output a representation of the statistic.

[0010] Details of one or more aspects of the present disclosure are set forth in the following drawings and description. Other features, objects, and advantages of the technology described in the present disclosure will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a conceptual diagram showing an exemplary system for delivering ablation and detecting catheter failures in accordance with one or more aspects of the present disclosure.

[0012] Figure 2 is a block diagram showing an exemplary controller of an ablation system in accordance with one or more aspects of the present disclosure.

[0013] Figure 3A and Figure 3B is a graph showing an exemplary measured reflected signal from a catheter in accordance with one or more aspects of the present disclosure.

[0014] Figure 4 is a flowchart showing an exemplary catheter health assessment technique in accordance with one or more techniques of the present disclosure. DETAILED DESCRIPTION

[0015] Figure 1is a conceptual diagram showing an exemplary system for delivering ablation and detecting catheter failures in accordance with one or more aspects of the present disclosure. System 100 includes a catheter 102 and a controller 104. Generally, for delivering ablation, a practitioner (e.g., an electrophysiologist, an interventional cardiologist, etc.) may insert one or more of the catheters 102 into a patient and cause the controller 104 to deliver energy (e.g., pulsed field ablation energy, radiofrequency ablation energy, etc.) via the catheter 102 to a target tissue of the patient. The ablation may cause damage in the target heart tissue, which may mitigate or stop arrhythmia. When ablation results in damage in the heart, it may be desirable for the system to safely and accurately provide information about ablation parameters to the clinician, such as the recommended positions of one or more energy delivery elements of one or more ablation catheters, the amount of energy to be delivered during ablation, or which tissue will be ablated after delivering ablation energy via at least one energy delivery element.

[0016] The catheter 102 may include an elongate structure 112 carrying a plurality of energy delivery elements 110A - 110H (collectively referred to as "energy delivery elements 110"). The energy delivery elements may include electrodes (e.g., in the case of a pulsed field ablation catheter), radiofrequency elements (e.g., in the case of a radiofrequency ablation catheter), or another energy delivery element. While the techniques of the present disclosure are applicable to any ablation catheter, Figure 1 an example of which relates to a pulsed field ablation catheter. The catheter 102 may generally include features that enable the catheter 102 to be inserted into a patient and enable the catheter 102 to be navigated to a target tissue site. The elongate structure 112 may include a distal portion 106 and a proximal portion 108. The energy delivery elements 110 may generally be located at the distal portion 106, while the proximal portion 108 may be connected to the controller 104. The energy delivery elements 110 may have any suitable geometry. Example geometries of electrodes include, but are not limited to, a circular (e.g., annular) electrode surrounding the body of a lead, a conformable electrode, a hoop electrode, a segmented electrode (e.g., electrodes disposed at different circumferential positions around a lead rather than a continuous annular electrode), and any combination thereof (e.g., an annular electrode and a segmented electrode). The energy delivery elements 110 may be axially distributed along the longitudinal axis LA of the elongate structure 112 or distributed in a plurality of other configurations. In some examples, the catheter 102 may include one or more energy delivery elements 110, and the geometry of one or more energy delivery elements 110 may include a balloon that may be inflated during ablation and deflated when navigating the catheter 102 to the target tissue. The delivery elements 110 may also be in a circular form, in an array, along a plurality of splines, or other configurations.

[0017] The elongate structure 112 can include conductors 114A through 114N (collectively referred to as "conductors 114"), which can be configured to carry electrical signals between the energy delivery element 110 and the controller 104 (shown in an exploded view). Examples of conductors 114 include but are not limited to wires (e.g., solid, braided, etc.), traces, and the like. In some examples, the elongate structure 112 can include individual conductors of the conductors 114 for each of the energy delivery elements in the energy delivery element 110. For example, in an example where the energy delivery element 110 includes eight electrodes Figure 1 the elongate structure 112 can include eight individual conductors (e.g., conductor 114A can carry an electrical signal for energy delivery element 110A, conductor 114B can carry an electrical signal for energy delivery element 110B,..., and conductor 114H can carry an electrical signal for energy delivery element 110H). In this way, the elongate structure can enable each electrode in the energy delivery element 110 to be driven with a different signal from the controller 104. In other examples, multiple electrodes in the energy delivery element 110 can share a common conductor. For example, energy delivery elements 110C and 110D can be connected to the same (e.g., shared) conductor of the conductors 114. Although such a common conductor arrangement may reduce the flexibility of the energy delivery elements (e.g., since electrodes connected to the common conductor can be driven with the same signal), such an arrangement can reduce manufacturing complexity and / or cost and can increase the structural flexibility of the catheter 102.

[0018] In some examples, the catheter 102 can be directly connected to the controller 104. In other examples, the catheter 102 can be connected to the controller 104 via a cable. For example, a cable can be connected to a connector of the catheter 102 and to a connector of the controller 104. The cable can include conductors configured to transfer electrical energy between the controller 104 and the catheter 102.

[0019] As Figure 1 shown, the energy delivery element 110 can include a distal electrode (e.g., electrode 110A), which can be an annular electrode having a "cap" that covers at least a portion of the distal end of the elongate structure 112. In some examples, the distal electrode can be beveled or otherwise rounded (e.g., to enable the catheter 102 to more easily pass through a patient's anatomy). The energy delivery element 110 can include an annular electrode adjacent to the distal electrode (e.g., electrode 110B). The annular electrode can be separated from the distal electrode (axially along the LA). The energy delivery element 110 can include one or more pairs of annular electrodes. A pair of annular electrodes can include two adjacent closely spaced electrodes in the energy delivery element 110. For example, in Figure 1In the example, energy delivery elements 110C and 110D may form a first pair of annular electrodes, energy delivery elements 110E and 110F may form a second pair of annular electrodes, and energy delivery elements 110G and 110H may form a third pair of annular electrodes. Generally speaking, the first pair of annular electrodes (i.e., energy delivery elements 110C and 110D) may be accompanied by one or more additional electrodes. The one or more additional electrodes may include any combination of annular electrode pairs and coil electrodes (e.g., electrodes including conductors helically wound around the elongate structure 112).

[0020] In Figure 1 the example, the energy delivery element 110 is illustrated as having a diameter greater than that of the elongate structure 112. In some examples, one or more of the energy delivery elements 110 may have a diameter that is approximately equal to or less than the diameter of the elongate structure 112. For example, the energy delivery element 110 may be recessed in the elongate structure 112 such that the combination results in a relatively smooth outer surface.

[0021] The controller 104 may include an energy generator configured to provide electrical pulses to the energy delivery element 110 to perform an ablation procedure on cardiac tissue or other tissue within 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 may be configured and programmed to deliver pulsed high-voltage electric fields suitable for achieving desired pulses, high-voltage ablation (referred to as "pulsed field ablation" or "pulsed electric field ablation") and / or pulsed radiofrequency ablation.

[0022] As described above, the conductor 114 may carry electrical signals between the controller 104 and the energy delivery element 110. Due to various circumstances, one or more of the conductor 114, the cable, or other components may become damaged (e.g., improper handling). During the delivery of energy (e.g., PFA ablation treatment) via the catheter 102, such a defect or failure may result in an undesired event. Thus, it may be desirable to determine whether the catheter 102 (or the associated cable) has any defects or failures.

[0023] According to one or more aspects of the present disclosure, the controller 104 may perform one or more operations to automatically detect a fault in the catheter 102. For example, the controller 104 may output a signal onto one of the conductors of the conductor 114 of the catheter 102 and measure the reflected signal generated by the output signal. The controller 104 may detect a fault in the catheter 102 based on the reflected signal (e.g., using a time domain reflectometer).

[0024] A signal incident on a conductor will propagate along the conductor at a substantial fraction of the speed of light, where that speed is determined by the impedance characteristics of the conductor. When a propagating signal encounters an impedance change, a portion of the signal continues to propagate in the forward direction and the remaining energy is reflected in the reverse direction. The time course of the signal at the source end of the conductor reveals the magnitude of the impedance change and, based on their time delay from the start of the source pulse, reveals their location along the conductor. Abrupt impedance changes such as those caused by an open or shorted conductor result in large increases and decreases in the detected magnitude, respectively. Thus, by monitoring the signal at the source end of the conductor in conductor 114, controller 104 can detect these changes and locate their position along the conductor in conductor 114. Additionally, in some examples, controller 104 can detect more subtle changes in impedance, such as a poor connection or a stressed conductor, via further analysis of the detected waveform. In this manner, controller 104 can detect faults in catheter 102.

[0025] Figure 2 is a block diagram showing an exemplary controller of an ablation system in accordance with one or more aspects of the present disclosure. Figure 2 The controller 200 of can be Figure 1 an example of the controller 104 of. As Figure 2 shown, the controller 200 can include an energy generator 202, a processing circuit 204, a user interface 206, and a storage device 208.

[0026] The energy generator 202 can be configured to control the energy delivery element 110 of catheter 102 ( Figure 1 ), such as to provide electrical pulses to an electrode (e.g., energy delivery element 110) to perform an electroporation procedure or other ablation procedure on cardiac tissue or other tissue within a patient's body, including but not limited to renal tissue, airway tissue, bone, organs, or tissue within the cardiac space or pericardial space. For example, the energy generator 202 can be configured and programmed to deliver pulsed high voltage electric fields suitable for achieving desired pulses, high voltage ablation (referred to as "pulsed field ablation" or "pulsed electric field ablation") and / or pulsed radiofrequency ablation. Thus, the energy generator 202 can be referred to as a PFA signal generator. Although shown as a single energy generator in the Figure 2 example of, the energy generator 202 is not so limited. For example, the controller 200 can include multiple energy generators, each capable of generating ablation signals in parallel. In some examples, the controller 200 can include different types of energy generators, such as a pulsed field energy generator and / or a radiofrequency energy generator.

[0027] The processing circuit 204 may include one or more processors, such as any 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), discrete logic circuitry, or any other processing circuit configured to provide the functionality attributed to the processing circuit 210 that may be embodied herein as firmware, hardware, software, or any combination thereof. The processing circuit 204 may execute instructions to control the energy generator 202 to generate signals according to various settings (e.g., the ablation module 222 delivers PFA ablation energy). In some examples, the processing circuit 204 may execute other instructions stored in the storage device 208 (e.g., the catheter health module 218) to perform catheter testing / fault detection.

[0028] The storage device 208 may be configured to store information within the controller 200 during operation. The storage device 208 may include a computer-readable storage medium or a computer-readable storage device. In some examples, the storage device 208 includes one or more of short-term memory or long-term memory. The storage device 208 may be in the form of, for example, random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), ferroelectric random access memory (FRAM), a magnetic disk, an optical disk, flash memory, or electrically programmable read-only memory (EPROM) or electrically erasable programmable read-only memory (EEPROM). In some examples, the storage device 208 is used to store data indicative of instructions executed, for example, by the processing circuit 204. The storage device 208 may be configured to store the catheter health module 218 and / or the ablation module 222.

[0029] The user interface 206 may include buttons or a keypad, lights, a speaker for voice commands, a display (such as a liquid crystal (LCD), light emitting diode (LED), or organic light emitting diode (OLED)). In some examples, the display may be configured to display a representation of catheter health statistics, as described in further detail herein. For example, the processing circuit 204 may implement the catheter health module 218 to perform testing of the catheter (e.g., Figure 1 catheter 102) and / or associated cables, and output the results via the user interface 206 (e.g., present a graphical user interface).

[0030] The display can be used to guide a clinician to position at least one energy delivery element in contact with or near a recommended target tissue such that the target tissue is ablated during delivery of energy to the at least one energy delivery element. In some examples, the display can show a representation of the target tissue that will be ablated after ablation energy is delivered via the at least one energy delivery element. The processing circuit 204 can then output a representation of the ablated tissue for display to the user interface 206. In some examples, the display includes a touch screen. The user interface 206 can be configured to display any information related to the performance of the ablation. The user interface 206 can also receive user input (e.g., selection of the target tissue) via the user interface 206. The user input can be in the form of, for example, pressing a button on a keypad or selecting an icon from the touch screen. The user interface 206 can indicate which conductors are available for ablation energy (with good connectivity to the delivery electrodes).

[0031] The telemetry circuit 220 can include any suitable hardware, firmware, software, or any combination thereof for communicating with another device. The telemetry circuit 220 can be configured to communicate using any one of a variety of wireless communication schemes (such as or low power WiFi, 4G, or 5G) or a wired communication scheme (such as Ethernet). Under the control of the processing circuit 204, the telemetry circuit 220 can receive downlink telemetry from one or more external devices and / or transmit uplink telemetry to the one or more external devices by means of an internal antenna or an external antenna or via a wire.

[0032] The measurement circuit 224 can include any suitable hardware, firmware, software, or any combination thereof for measuring an electrical signal from a catheter connected to the controller 200. For example, the measurement circuit 224 can include one or more analog-to-digital converters (ADCs) configured to convert analog voltage measurements (e.g., the voltage level of a signal measured at the proximal end of a conductor of the catheter) into digital values that can be processed by the processing circuit 204.

[0033] As described above, the processing circuit 204 can implement the catheter health module 218 to perform catheter testing / fault detection. To perform catheter testing / fault detection, the processing circuit 204 can implement the catheter health module 218 to cause the energy generator 202 to output an electrical energy pulse onto the proximal end of a first conductor of a plurality of conductors of a catheter for performing pulsed field ablation (PFA) on a target tissue of a patient. For example, the energy generator 202 can output an electrical pulse onto Figure 1on one of the conductors 114 of the catheter 102. One or more other conductors in the conductor 114 can be used to establish a return path. The electrical energy pulse can have a voltage level less than N volts (e.g., 50 millivolts, 0.5 volts, 1 volt, 2 volts, 3 volts, 4 volts, 5 volts). In some examples, the pulse can be a square wave pulse. In other examples, more complex signals (e.g., single-cycle or half-cycle sine waves) can be used.

[0034] The pulse can propagate along the conductor until it reaches any change in impedance. As described above, a change in impedance can cause a portion of the signal to be reflected back to the proximal end of the conductor. The measurement circuit 224 can measure the reflected electrical energy signal generated by the electrical energy pulse at the first conductor. For example, the ADC of the measurement circuit 224 can convert the voltage level at the proximal end of the first conductor into a stream of digital values and provide these digital values to the processing circuit 204.

[0035] The controller 200 can determine the health statistics of the catheter based on the measured reflected electrical energy signal. Generally, the health statistics are measurements representing the viability of the conductor. For example, the processing circuit 204 can execute the catheter health module 218 to analyze the digital values to determine the health statistics, e.g., whether the conductor has any faults. In some cases (e.g., under low-noise conditions), the controller 200 can use a single pulse to perform catheter testing / fault detection. In other cases, the controller 200 can use multiple pulses (and their corresponding return signals) to perform catheter testing / fault detection (e.g., the pulse can be repeated periodically and measured so that signal averaging or other processing steps can be used to improve the detection accuracy).

[0036] To determine the health statistics based on the reflected electrical energy signal, the controller 200 can determine the time displacement between the first time when the output electrical energy pulse is sent and the second time when the reflected electrical energy signal is received. The time displacement between the first time and the second time can indicate the location of the impedance change along the catheter. Since the impedance change may be the result of a fault or other damage, the time displacement represents the location of the fault along the catheter (e.g., determined based on the signal propagation speed). In some examples, the controller 200 can use morphological template matching (e.g., templates for "good" and "bad" states) to determine the presence of a fault.

[0037] The controller 200 can determine the health statistics to indicate whether the catheter is faulty or not. In the case where the controller 200 determines the health statistics to indicate that the catheter has one or more faults, the health statistics can indicate the location of the fault on the catheter (e.g., 30 cm from the proximal end).

[0038] In some examples, the controller 200 may perform signal output and measurement on a single conductor of the catheter. In other examples, the controller 200 may perform signal output and measurement on multiple conductors of the catheter. For example, the controller 200 may output a corresponding pulse of a plurality of pulses to a corresponding one of the plurality of conductors, and measure a corresponding reflected energy signal of the plurality of reflected energy signals at each corresponding one of the plurality of conductors. Thus, in some examples, the controller 200 may determine a single health statistic representative of all conductors (e.g., determine a health statistic of the catheter based on the plurality of reflected energy signals).

[0039] The controller 200 may output a representation of the statistic. As an example, the processing circuit 204 may cause the user interface 206 to display a binary representation of whether the catheter has a fault. As another example, the processing circuit 204 may cause the user interface 206 to display a graphical user interface (GUI) that indicates whether the catheter has a fault, which conductors of the catheter have a fault, and / or the location of the fault.

[0040] In some examples, in addition to or instead of outputting a representation of the statistic, the controller 200 may perform one or more actions. As an example, in response to the health statistic of the catheter indicating a fault in the catheter, the controller 200 may prevent delivery of ablation energy (e.g., PFA ablation energy) via the catheter. For example, the catheter health module 218 may prevent the ablation module 222 from causing the energy generator 202 to output ablation energy via the catheter.

[0041] Figure 3A and Figure 3B is a graph showing exemplary measured reflection signals from a catheter in accordance with one or more aspects of the present disclosure. Figure 3A Shows an exemplary reflection signal from a conductor of a catheter having an impedance matching termination at its distal end. For example, Figure 3A shows the measured reflection signal from a 2 meter (m), 50 ohm coaxial cable having a 50 ohm termination at its distal end, the measured reflection signal being excited with a 10 MHz square wave having a 30 picosecond (ps) rise time. Figure 3A The flat top of the signal of Figure 3B indicates no impedance change along the length of the conductor. Figure 3B Shows an exemplary reflection signal from a conductor of a catheter having an open distal end. For example, Figure 3A shows the reflection signal measured from the same cable as Figure 3BAs can be seen, after 20 nanoseconds (ns), corresponding to the round-trip propagation time of a 2m cable, there is a sudden jump (doubling) in the magnitude. If the conductor being excited is interrupted midway along its length, this doubling will occur at 10 ns, thereby signaling a fault condition at that location (i.e., at the midpoint location).

[0042] Figure 4 is a flowchart showing an exemplary ablation catheter health assessment technique in accordance with one or more techniques of the present disclosure. Figure 4 The technique can be performed by a controller (such as Figure 1 controller 104 of Figure 2 or controller 200).

[0043] Controller 200 can output an electrical energy pulse to a first conductor among a plurality of conductors of a catheter for performing irreversible electroporation (IRE) (such as pulsed field ablation (PFA)) on a target tissue of a patient (402). For example, controller 104 can cause a signal generator to output an electrical energy pulse to the proximal end of conductor 114A (e.g., when the distal end of conductor 114A or an electrode connected thereto is connected to one or more other conductors of conductor 114 or an electrode connected thereto).

[0044] Controller 200 can measure a reflected electrical energy signal generated by the electrical energy pulse at the first conductor (404). For example, controller 104 can sense the voltage level at the proximal end of conductor 114A. As described above, the ADC can convert the sensed voltage level into a digital value.

[0045] Controller 200 can determine the health statistics of the catheter based on the measured reflected electrical energy signal (406). For example, controller 104 can perform a time domain reflectometer (TDR) to analyze the measured reflected electrical energy signal and determine whether there are any faults along conductor 114A. The health statistics can indicate whether controller 104 has detected any faults. As described above, controller 104 can perform TDR on a plurality of conductors of the catheter or can perform TDR on a single conductor of the catheter. Thus, the statistics can represent the health of one or more of the conductors.

[0046] Controller 200 can output a representation of the statistics (408). As an example, controller 104 can cause user 206 to display a binary representation of whether the catheter has a fault. As another example, controller 104 can cause the user interface to display a graphical user interface (GUI) that indicates whether the catheter has a fault, which conductors of the catheter have a fault, and / or the location of the fault.

[0047] The controller 200 may perform an ablation catheter health assessment at one or more moments during the catheter life cycle. As an example, the controller 200 may perform an ablation catheter health assessment after the system components are connected, which may be referred to as a system connection check (e.g., to assess connectivity). As another example, the controller 200 may perform an ablation catheter health assessment after the catheter is placed, which may be referred to as a conductor disconnection check (e.g., to assess whether effective therapy is possible or whether there are issues with the catheter interface cable (CIC) (e.g., the cable that connects the proximal end of the catheter to the controller) that can be remedied without having to remove the catheter). As another example, the controller 200 may perform an ablation catheter health assessment after attempting therapy delivery, which may be referred to as a therapy integrity check (e.g., to determine whether the conductor was damaged during therapy delivery).

[0048] For the system connection check, the controller 104 may sequentially and individually connect the pulse source to each electrode terminal (e.g., each conductor). All other terminals may be connected together and used as a signal return path. As described above, a sudden rise in the signal magnitude value indicates an open circuit condition, and its occurrence time relative to the input signal indicates its location. Analysis of the signal will confirm the connection from the generator to the distal end of the cable. A disconnected CIC may cause an early doubling of the signal magnitude value. Similarly, a disconnected catheter may be revealed by an increase in the signal magnitude value (e.g., after an additional 25 ns). This check may be performed before the catheter is inserted into the patient or while the catheter is in place. In response to detecting a fault, the controller 104 may output a system warning that indicates to the user how to mitigate the problem or prevent therapy delivery via the damaged conductor / electrode. This may also be a mechanism to allow system compatibility of the signal generator with catheter designs having "less than the allowed maximum" electrodes (limiting energy delivery to only the connected conductor / electrode). Thus, a procedure that would otherwise have to be cancelled may continue with reduced functionality.

[0049] For the conductor disconnection check, the controller 104 may use the same measurement scheme as described above and may determine the location of the disconnected (open) conductor based on the rise in the signal magnitude value. By examining the time between the source edge and the rise, the controller 104 can not only diagnose the presence of a disconnected connection but also localize the disconnected connection to the CIC or the catheter. A short circuit between a conductor and one or more of its adjacent conductors may be detected based on a sudden decrease in the signal magnitude value. The controller 104 may perform this check, which may be performed before the catheter is inserted or while the catheter is in place. Performing the check once the catheter is in place can be particularly valuable as it can detect a break in the CIC (e.g., which can be remedied without having to remove the catheter). This procedure can also ensure patient connection, enabling effective therapy delivery.

[0050] For therapy integrity checking, the controller 104 can use the same measurement scheme as described above to perform a conductivity assessment after delivering therapy energy. In this way, the controller 104 can determine whether the conductor has been damaged during therapy delivery. If the conductor is damaged during therapy delivery, effective therapy cannot be guaranteed.

[0051] The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, 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 circuitry; and any combination of such components. The term "processor" or "processing circuit" generally may refer to any of the foregoing logic circuitry alone or in combination with other logic circuitry, or any other equivalent circuitry. A control unit including hardware may also form one or more processors or processing circuits configured to perform one or more of the techniques of this disclosure.

[0052] Such hardware, software, and firmware may be implemented and various operations may be performed, on a coordinated basis, within the same device, within separate devices, and / or within, between, or across multiple devices to support the various operations and functions described in this disclosure. Additionally, any of the described units, circuits, or components may be implemented together or independently 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 or software components. Instead, the functions associated with one or more circuits or units may be performed by separate hardware or software components, or integrated within common or separate hardware or software components. The processing circuit including one or more processors described in this disclosure may be implemented as fixed function circuitry, programmable circuitry, or a combination thereof in various examples. Fixed function circuitry refers to circuitry that provides specific functionality using preset operations. Programmable circuitry refers to circuitry that can be programmed to perform various tasks and provide flexible functionality in the operations that can be performed. For example, programmable circuitry may execute software or firmware that causes the programmable circuitry to operate in a manner defined by the instructions of the software or firmware. Fixed function circuitry may execute software instructions (e.g., to receive stimulation parameters or output stimulation parameters), but the types of operations performed by the fixed function circuitry are generally immutable. In some examples, one or more of these units may be different circuit blocks (fixed function or programmable), and in some examples, one or more of these units may be integrated circuits.

[0053] The techniques described in this 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 when executing these instructions. The computer-readable storage medium may include random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette tape, a magnetic medium, an optical medium, or other computer-readable media.

[0054] The following examples are a non-limiting list of articles according to one or more techniques of this disclosure.

[0055] Example 1. A method for assessing catheter integrity, the method comprising:

[0056] Outputting, by a device, an electrical energy pulse to a first conductor of a plurality of conductors of a catheter for performing irreversible electroporation (IRE) on a target tissue of a patient; measuring, by the device, a reflected electrical energy signal generated by the electrical energy pulse at the first conductor; determining, by the device, a health statistic of the catheter based on the measured reflected electrical energy signal; and outputting, by the device, a representation of the statistic.

[0057] Example 2. The method according to Example 1, wherein the device is an IRE signal generator.

[0058] Example 3. The method according to Example 1, wherein the device does not include an IRE signal generator.

[0059] Example 4. The method according to any one of Examples 1 to 3, wherein outputting the pulse to the first conductor includes: outputting a first pulse of a plurality of pulses to the first conductor, the method further comprising: outputting, by the device, a corresponding pulse of the plurality of pulses to a corresponding conductor of the plurality of conductors; and measuring, by the device, a corresponding reflected energy signal of a plurality of reflected energy signals at each corresponding conductor of the plurality of conductors, wherein determining the health statistic of the catheter includes: determining the health statistic of the catheter based on the plurality of reflected energy signals.

[0060] Example 5. The method according to Example 4, wherein the health statistic of the catheter includes a corresponding health statistic of each conductor of the plurality of conductors, such that determining the health statistic includes determining a plurality of health statistics.

[0061] Example 6. The method according to any one of Examples 1 to 5, wherein assessing the integrity of the catheter includes: assessing the integrity of the catheter before delivering IRE ablation energy to the patient via the catheter.

[0062] Example 7. The method according to Example 6, wherein assessing the integrity of the catheter before delivering IRE ablation energy to the patient includes: assessing the integrity of the catheter after inserting the catheter into the patient but before the delivery of the IRE ablation energy.

[0063] Example 8. The method according to Example 6 or Example 7, the method further comprising: in response to the health statistics of the catheter indicating a fault in the catheter, preventing the delivery of the IRE ablation energy via the catheter.

[0064] Example 9. The method according to any one of Examples 1 to 5, wherein assessing the integrity of the catheter includes: assessing the integrity of the catheter after delivering the IRE ablation energy to the patient via the catheter.

[0065] Example 10. The method according to any one of Examples 1 to 9, wherein outputting the electrical energy pulse includes: outputting the electrical energy pulse at a voltage level less than 5 volts.

[0066] Example 11. The method according to any one of Examples 1 to 10, the method further comprising: based on the time displacement between a first time of outputting the electrical energy pulse and a second time of receiving the reflected electrical energy signal, determining the location of a fault between the pulse generating device and the delivery electrode of the catheter, wherein the health statistics indicate the determined location of the fault.

[0067] Example 12. The method according to any one of Examples 1 to 11, wherein the catheter is connected to the device via a cable, and wherein the health statistics include the health statistics of the cable.

[0068] Example 13. A device, the device comprising: a memory; a signal generator; and a processing circuit configured to perform the method according to any one of Examples 1 to 12.

[0069] Example 14. A computer-readable storage medium storing instructions that, when executed, cause a device to perform the method according to any one of Examples 1 to 12.

Claims

1. A method for assessing catheter integrity, the method comprising: Outputting, by a device, an electrical energy pulse onto a first conductor of a plurality of conductors of a catheter for performing irreversible electroporation (IRE) on a target tissue of a patient; Measuring, by the device, a reflected electrical energy signal generated by the electrical energy pulse at the first conductor; Determining, by the device, a health statistic of the catheter based on the measured reflected electrical energy signal; And Outputting, by the device, a representation of the statistic.

2. The method according to claim 1, wherein the device is an IRE signal generator.

3. The method according to claim 1, wherein the device does not include an IRE signal generator.

4. The method according to any one of claims 1 to 3, wherein outputting the pulse onto the first conductor comprises: Outputting a first pulse of a plurality of pulses onto the first conductor, the method further comprising: Outputting, by the device, a corresponding pulse of the plurality of pulses onto a corresponding conductor of the plurality of conductors; and Measuring, by the device, a corresponding reflected energy signal of a plurality of reflected energy signals at each corresponding conductor of the plurality of conductors, wherein determining the health statistic of the catheter comprises: determining the health statistic of the catheter based on the plurality of reflected energy signals.

5. The method according to claim 4, wherein the health statistic of the catheter comprises a corresponding health statistic of each conductor of the plurality of conductors, such that determining the health statistic comprises determining a plurality of health statistics.

6. The method according to any one of claims 1 to 5, wherein assessing the integrity of the catheter comprises: Assessing the catheter integrity before delivering IRE ablation energy to the patient via the catheter.

7. The method according to claim 6, wherein assessing the integrity of the catheter before delivering IRE ablation energy to the patient via the catheter comprises: Assessing the catheter integrity after inserting the catheter into the patient but before the delivery of the IRE ablation energy.

8. The method according to claim 6 or claim 7, the method further comprising: In response to the health statistic of the catheter indicating a fault in the catheter, preventing the delivery of the IRE ablation energy via the catheter.

9. The method according to any one of claims 1 to 5, wherein assessing the integrity of the catheter comprises: Assessing the catheter integrity after delivering the IRE ablation energy to the patient via the catheter.

10. The method according to any one of claims 1 to 9, wherein outputting the electrical energy pulses comprises: Outputting the electrical energy pulse at a voltage level less than 5 volts.

11. The method according to any one of claims 1 to 10, the method further comprising: Determining, based on a time displacement between a first time of outputting the electrical energy pulse and a second time of receiving the reflected electrical energy signal, a location of a fault between the pulse generating device and a delivery electrode of the catheter, wherein the health statistic indicates the determined location of the fault.

12. The method according to any one of claims 1 to 11, wherein the catheter is connected to the device via a cable, and wherein the health statistic comprises a health statistic of the cable.

13. A device, the device comprising: A memory; A signal generator; And A processing circuit configured to perform the method according to any one of claims 1 to 12.

14. A computer-readable storage medium storing instructions that, when executed, cause a device to perform the method according to any one of claims 1 to 12.

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