Isolation interface apparatuses and methods for high-voltage medical treatment

Abstract

Methods and apparatuses for isolating and switching between electrical monitoring and electrical ablation that may be used with an electrical applicator, e.g., catheter that may include both monitoring and ablation electrodes. The isolating apparatus may provide rigorous isolation between the ablation components and the monitoring components. These methods and apparatuses may be particularly useful for systems that apply high voltage electric pulses.

Description

ISOLATION INTERFACE APPARATUSES AND METHODS FOR HIGH-VOLTAGE MEDICAL TREATMENTCLAIM OF PRIORITY

[0001] This patent application claims priority to U.S. provisional patent application no.63 / 746,240, titled “ISOLATION INTERFACE APPARATUSES AND METHODS FOR HIGH-VOLTAGE MEDICAL TREATMENT,” filed on January 16, 2025, and herein incorporated by reference in its entirety.BACKGROUND

[0002] Ablation may be used to treat various conditions, for example, cardiac disorders, including abnormal heart rhythms like atrial fibrillation (AFib), atrial flutter, supraventricular tachycardia (SVT), and ventricular tachycardia (VT), as well as non-cardiac disorders. A variety of ablation techniques can be used, such as radiofrequency (RF), ultrasound, microwave, pulsed electric field, cryoablation, and other forms of ablation. In particular, it may be beneficial to use high voltage electrical pulses delivered through a catheter. When delivering ablation by electrical techniques, it may be beneficial to use the same catheter for the delivery of ablation energy as well as for electrophysiological mapping, pacing, or position tracking / navigation, including measuring electrograms, to assist in guiding the application of ablation.

[0003] However, it may be particularly challenging to combine ablation, and in particular, high voltage ablation to treat tissue (e.g., voltage greater than 0.5Kv) with low voltage supplemental systems, such as electrocardiography (ECG), electroencephalography (EEG), electromyography (EMG), cardiac pacing systems, bispectral index (BIS) systems, tissue / clot sensing (e.g., bioimpedance) systems, etc. One non-limiting example of such supplemental systems are mapping systems, also known as Electrophysiological Diagnostic Systems (EDS) , that may be configured to detect very low voltages or currents (e.g., millivolts or microamps) from tissue. Difficulties may arise when attempting to operate one or more such low voltage supplemental systems, such as for monitoring, navigation, etc., either concurrently with operation of a high voltage system or when switching between the one or more low voltage (e.g., monitoring) systems and high voltage system. Thus, there is a need for apparatuses to isolate and protect supplemental systems from ablation systems, especially those involving high voltages, such as during high voltage ablation.- 1 - 14567-738.600 / 135 PCTSUMMARY OF THE DISCLOSURE

[0004] Described herein are methods and apparatuses for isolating and switching between low voltage supplemental electrical systems (e.g., for monitoring a patient, including mapping, etc.) and high voltage electrical systems (e.g., for electrical ablation). These methods and apparatuses may be used with an electrical applicator, e.g., catheter, probe, percutaneous delivery device (just to name a few), that includes both monitoring / sensing and ablation modalities (e.g., electrodes) and may be configured to provide rigorous isolation between the high voltage (e.g., ablation) components and the lower voltage (e.g., monitoring / sensing) components. These methods and apparatuses are not limited to apparatuses and method in which the same applicator is used for both low voltage and high voltage, but may provide isolation between low voltage (e.g., sensing) inputs in proximity to a high voltage electrodes when a high voltage is applied, e.g., during a treatment. These methods and apparatuses may be particularly useful for systems that apply short, high voltage electrical pulses to selectively destroy, manipulate or modify targeted tissue (e.g., soft tissue, including but not limited to cardiac tissue, and / or anatomical structures), and may be used for treating various conditions, including but not limited to cardiac arrhythmias like atrial fibrillation or ventricular tachycardia or fibrillation. Ultra-short electric pulses may create tiny pores in cell membranes without generating necrotizing heat, potentially reducing the risk of damage to nearby structures like the esophagus and phrenic nerve compared to traditional thermal ablation methods like radiofrequency or cryogenic ablation. One example of such electric pulses are pulses of microsecond or sub-microsecond (e.g., nanosecond) duration.

[0005] Any of the isolation apparatuses described herein may use one or more low-cost relays for isolating high voltage and high current pulses from one or more supplemental systems that may be connected to the same applicator and may even share electrodes with the high voltage components, such as a pulse generator. These methods and apparatuses may also be used for isolating high voltage and high current pulses from one or more supplemental systems that may include a separate applicator / sensor that is configured to connect to the same patient, including the same region of the body on the patient. In some cases this may be accomplished by isolating / floating the entire relay, so that there is no high potential across any parts of the relay. Any of these methods and apparatuses may also use state detection circuits (e.g., isolation state detection circuits, including relay state detection circuits) to directly monitor the state of the relays isolating the high voltage components (e.g., pulse generator) from the supplemental systems to ensure the isolation components of the apparatus-2 - 14567-738.600 / 135 PCTare functioning as intended, and / or are not damaged or have reduced functionality due to the high voltage treatments. Finally, these methods and apparatuses may also be configured to cold switch all of the relays of the isolation apparatus. For example the isolation apparatus may switch the relays to a target state prior to connecting to the pulse generator and / or supplemental system(s) or prior to activating HV treatment (ablation). This allows the isolation apparatus to use smaller relays and may dramatically extend their service life.

[0006] A low voltage supplemental system may include any appropriate low voltage system that may be used in conjunction with (sequentially and / or concurrently) with a high voltage system. Any appropriate supplemental system may be used, including but not limited to mapping systems (e.g., electrical mapping systems, such as electroanatomical mapping, intracardiac mapping, etc.), ultrasound mapping systems (e.g., intracardiac echocardiography), pacing and / or triggering systems, bispectral index (BIS) systems, electromyography systems, neuromuscular blocking monitoring, hemodynamic monitoring systems, pulse oximeter systems, EEG monitoring systems, evoked potential monitoring, temperature (e.g. skin, esophageal, etc.) probes, respiratory impedance monitoring systems, etc. Although many of the examples of low voltage supplemental systems described herein refer to cardiac mapping systems, it should be understood that this is only one example of a low voltage supplemental system. The method and apparatuses described herein are intended to cover isolation and protection of any low voltage supplemental system, including but not limited to cardiac monitoring or mapping system, from any high voltage treatment system. The methods and apparatuses described herein are not limited to cardiac applications but should be interpreted broadly to include any appropriate low voltage, supplemental system and high voltage treatment system. For example, these methods and apparatuses (including in particular, the isolation apparatuses and methods) may be configured for non-cardiac uses, including neurological applications, such as ablating at or near nerves in non-cardiac applications and may use one or more sensing electrodes to activate / stimulate nearby nerves to assess nerve function following ablation. Neurological procedures may benefit from realtime electrical monitoring to help guide surgical interventions and manage therapeutic devices (including ablation devices). For example, the low voltage (e.g., supplemental) systems may include neuromodulation systems such as, but not limited to electroencephalographic devices (EEGs), spinal cord stimulator systems, deep brain stimulator systems, vagus nerve stimulator systems, electrical stimulation, etc. Any of these supplemental systems may include nerve mapping systems. Any of methods and apparatuses of the present disclosure may be used in the various procedures and applications, e.g., to treat cancers, tumors, etc.-3 - 14567-738.600 / 135 PCT

[0007] The high voltage systems described herein may generally refer to high voltage treatment systems and may include ablation systems. These systems may be electrical ablation systems delivering (e.g., microsecond or sub-microsecond / nanosecond electrical pulses, RF energy, microwave, or high-current pulses, etc.) from a generator, e.g., pulse generator, to an applicator, enabling the effective ablation, electrocautery or coagulation of tissue or physiological fluids.

[0008] The isolation apparatuses described herein may be referred to as an isolation interface or switching device that may provide extremely high isolation between one or more low voltage supplemental systems and high voltage treatment system. In any of the methods and apparatuses described herein, these isolation apparatuses may include state detection to ensure that the relays (e.g., high voltage, HV, relays) are in the correct state before initiating HV treatment, such as pulsing. These isolation apparatuses may avoid “sticking” of the relays (e.g., in some cases HV reed relays) that are a common failure mode. These methods and apparatuses may be configured to ensure that the isolation relays for the low voltage supplemental system(s) are in a “disconnected” state prior to applying high voltage pulsing for ablation, preventing relay failures. In general, these systems and apparatuses may also be configured to withstand high dielectric breakdown, particularly when using high working voltages (e.g., voltages greater than about 500V, 550V, 600V, 650V, 700V, 750V, 800V, 900V, IkV, etc.). The systems and apparatuses described herein may also be configured to isolate any electromagnetic (EM) sensor signals and isolate specific circuits (e.g., connector detection circuits) while providing a high degree of isolation.

[0009] In general, the isolation apparatus (e.g., switching device) may be a stand-alone apparatus or may be integrated into a pulse generator or other treatment systems, such as high voltage treatment systems. For example, in some cases the isolation apparatus may include a cable configured to couple to the pulse generator for high voltage transmission. Thus, the isolation apparatus may be an interface between a high voltage treatment system (e.g., high voltage pulse generator), one or more low voltage supplemental systems and one or more applicators or low voltage (LV) monitoring sensors (pulse oximeter sensors, blood pressure sensors, etc.). The one or more applicators / sensors may include electrodes for either or both high voltage output (e.g., ablation) and / or low voltage (e.g., monitoring / sensing). The applicator may be, for example, a catheter, a probe, a percutaneous delivery device, or other tool. In some cases the applicator may be a combined low voltage and high voltage applicator, such as a combined mapping / sensing and ablation catheter. In some examples separate low voltage (e.g., sensing, mapping, etc.) and high voltage (e.g., ablation) applicators may be used. In other examples separate low voltage sensors (e.g., pulse-4 - 14567-738.600 / 135 PCToximeter, blood pressure, BIS anesthesia EEG electrodes, ECG electrodes, etc.) and high voltage (e.g., pulse field ablation, RF ablation, microwave ablation, electro surgical cautery or cutting, or combinations of these) applicators may be used. In some cases the monitoring (mapping, sensing, etc.) and ablation catheter may be integrated and may share electrodes for both mapping an ablation and / or may have separate mapping and ablation electrodes. The isolation apparatus may be configured to connect to other supplemental devices, including other monitoring / sensing devices or systems, on or in the patient, such as (but not limited to) pacing catheters and / or EGM pads. Other devices or systems that may be coupled to the isolation apparatus may include navigation systems, electrogram (EGM) signal visualizers, etc.

[0010] In general, the isolation apparatuses described herein may use one or more first set of switches, e.g., relays, to connect and disconnect sensing electrodes located on an applicator (e.g., catheter) from the other system components that use and / or control these electrodes / sensors. The isolation apparatus may use another (e.g., a second) set of switches to connect and disconnect ablations / treatment electrodes on the same or different applicator (e.g., catheter) from the pulse generator (e.g., HV source); in some cases the same electrodes may be used for sensing / monitoring and the application of ablation (e.g., HV treatment electrodes).

[0011] Any of these methods and apparatuses may also connect and disconnect other sensors in / on the patient by passing signals through the isolation apparatus. Thus, the isolation apparatus may be configured to be placed in a sensing or monitoring state in which various components are isolated from the components in the treatment state. For example, in some cases the isolation apparatus may be configured to enable low voltage activity (e.g., monitoring / sensing) by setting switches to the pulse generator as ‘open’ and switches to the low voltage (e.g., monitoring / sensing) system as closed; in this state, all the low voltage sensors and devices in and on the body can be used and can communicate with the monitoring / mapping system or other low voltage components. In this configuration, each signal that passes through a switch to the output side may continue to the appropriate system or equipment via connectors and cables. The circuitry isolation interface of the system may include a branching path to grounded protection components, to protect the lower voltage (e.g., sensing / monitoring) equipment. In some cases this branching path may include a transient voltage suppressor diode (TVS) or a gas discharge tube (GDT). Each switch of the second set of switches may include its own TVS / GDT. After the TVS diode(s), all lines may be tied together to earth ground. This TVS / gas discharge pathway to ground may be practically "open" when not required for protection of the low voltage components (e.g.,-5 - 14567-738.600 / 135 PCTmapping system) and may be shorted when necessary to protect the low voltage components from the high voltage pulses.

[0012] When treatment is to be delivered, e.g., by applying energy to ablate and connecting the treatment electrodes (and / or the common treatment / sensing electrodes), the isolation apparatus may be configured to transition to the treatment state in which the one plurality of switches is open and another plurality of switches is closed. In this state, all the sensors on or near the body, which can be exposed to voltage potential fields and also possible coupling with the HV pulses, are disconnected from the equipment used to control and sense from those devices.

[0013] Any of the apparatuses and methods described herein may also be configured to include an earth ground switch. The earth ground switch may connect the protection circuitry of the one or more low voltage supplemental systems to the earth ground in the high voltage treatment mode (that may be referred herein as the pulsing mode), but disconnect, e.g., isolate, the protection circuity from the earth ground in the monitoring mode. The earth ground switch may be activated by switching between the high voltage treatment (pulsing) mode and the low voltage (monitoring) mode, and the switching components of the earth ground switch may also include similar state detection circuitry as the first and second relays.

[0014] In general, the switching of the isolation apparatus can be fast and can be controlled by the pulse generator or by an external input.

[0015] For example, described herein are isolation apparatuses comprising: a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from a first applicator comprising one or more electrodes in a high voltage (HV) treatment mode and to connect the LV supplemental system to the first applicator or a second applicator in a monitoring mode; a second one or more relays configured to connect a high voltage (HV) treatment system to the first applicator in the HV treatment mode and to electrically isolate the HV treatment system from the first and / or second applicator and the LV supplemental system in the monitoring mode; a relay state detection circuit configured to continuously detect, in real time, a state of the first one or more relays and a state of the second one or more relays in respective HV treatment mode and monitoring mode; and a controller configured to: receive an output from the relay state detection circuit; compare the output from the relay state detection circuit with an expected output to perform failure detection of the first or the second one or more relays; and switch between the HV treatment mode and the monitoring mode.

[0016] In any of these methods and apparatuses, the same applicator may be used for delivering the HV treatment and the LV treatment. For example, described herein are-6 - 14567-738.600 / 135 PCTisolation apparatuses comprising: a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from an applicator comprising one or more electrodes in a high voltage (HV) treatment mode and to connect the LV supplemental system to the applicator in a monitoring mode; a second one or more relays configured to connect a high voltage (HV) treatment system (e.g., a pulse generator) to the applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator and the low voltage supplemental system in the monitoring mode; an isolated state detection circuit (e.g., relay state detection circuit) configured to continuously detect, in real time, a state of the first one or more relays and a state of the second one or more relays in respective HV treatment mode and monitoring mode; and a controller configured to: receive an output from the relay state detection circuit; compare the output from the relay state detection circuit with an expected output to perform failure detection of the first or the second one or more relays; and switch between the HV treatment mode and the monitoring mode.

[0017] Any of these apparatuses may include a plurality of ports configured to couple to a plurality of cables for connection to the LV supplemental system, the applicator and / or the HV treatment system (e.g., pulse generator.) The supplemental system may comprise at least one of a sensing system, a mapping system, a position tracking / navigation system and / or a pacing system, etc., any or all of which may be referred herein for convenience of description as a monitoring system. The controller may be configured to communicate with the LV supplemental system and HV treatment system and report the respective HV treatment mode and the monitoring mode, as well as fault conditions if they occur.

[0018] In any of these apparatuses the isolation apparatus may be configured to transmit pulses up to 50kV from the HV treatment system, such as a pulse generator, to the applicator in the HV treatment / pulsing mode. The apparatus may be configured to receive electric pulses in microsecond and sub-microsecond ranges. In general, the apparatus may be a part of a system comprising the pulse generator and the applicator and wherein the applicator comprises one or more ablation electrodes and, for example, a plurality of sensing and / or mapping electrodes. In addition, any of these applicators may comprise an electromagnetic (EM) sensor. The applicator may comprise one or more electrodes configured to operate in dual mode: adapted to be in electrical communication with the LV supplemental system in a sensing (e.g., mapping) mode and with the pulse generator in the pulsing mode.

[0019] In any of these apparatuses, the isolator state detection circuit (e.g., relay state detection circuit) may be isolated from the first and / or the second one or more relays, for example, by a high-frequency isolator such as an opto-isolator and / or isolated power supply. The protection circuits (e.g., the relays of the protection circuit(s)) may be configured to -7 - 14567-738.600 / 135 PCTshunt current from the LV signal lines within the apparatus to ground when a voltage on the LV lines is above a threshold (e.g., above 375 V).

[0020] The second one or more relays may be electrically isolated entirely by one or more high frequency / low capacitance isolators. The second one or more relays may be a low voltage power relay. In some implementations, the second one or more relays may be configured to withstand, for example, up to 1400 A. The apparatus may further comprise a plurality of bidirectional protection circuits or circuit components (e.g., diodes).

[0021] In general, in some implementations the supplemental system may be a part of a system that also comprises a pulse generator or other high voltage treatment device / system.

[0022] As mentioned, any of these protect! on / i solation apparatuses may be also configured to protect the low voltage supplemental system(s), from potential high voltage stimulation that may arise even when the pulsing mode is disabled (e.g., in the monitoring mode), as may occur, for example, when defibrillation is applied. Thus, any of the apparatuses described herein may include an earth ground switch that is configured to disconnect one or more low voltage protection circuits from an earth ground, thereby limiting voltages of the signal lines to the low voltage system, in the monitoring mode and to connect the one or more low voltage protection circuits to the earth ground in the pulsing mode.

[0023] Also described herein are isolation apparatuses comprising: a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from a first applicator comprising one or more electrodes in a high voltage (HV) treatment mode and to connect the LV supplemental system to the first applicator or a second applicator in a monitoring mode; a second one or more relays configured to connect a high voltage (HV) treatment system (for example, a pulse generator system) to the first applicator in the HV treatment / pulsing mode and to electrically isolate the HV treatment system from the first and / or second applicator in the monitoring mode, wherein the second one or more relays is itself electrically isolated such that an activation coil of the second one or more relays is electrically isolated by one or more high voltage, low capacitance isolator; and a controller configured to switch between the HV treatment mode and the monitoring mode to protect the LV supplemental system from an output of the HV treatment system, for example, pulse generator. These isolation apparatuses may include any of the features described above.

[0024] As mentioned, the same applicator may be used for delivering the HV treatment and the LV treatment. For example, an isolation apparatus may comprise: a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from an applicator comprising one or more electrodes in a high voltage (HV) treatment mode and to connect the LV supplemental system to the applicator in a monitoring mode; a second one or -8 - 14567-738.600 / 135 PCTmore relays configured to connect a high voltage (HV) treatment system (for example, a pulse generator system) to the applicator in the HV treatment / pulsing mode and to electrically isolate the HV treatment system from the applicator in the monitoring mode, wherein the second one or more relays is itself electrically isolated such that an activation coil of the second one or more relays is electrically isolated by one or more high voltage, low capacitance isolator; and a controller configured to switch between the HV treatment mode and the monitoring mode to protect the LV supplemental system from an output of the HV treatment system, for example, pulse generator. These isolation apparatuses may include any of the features described above.

[0025] The one or more high voltage, low capacitance isolator may comprise one or more opto-isolators.

[0026] According to some further implementations, an isolation apparatus may include: a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from an applicator in a pulsing mode and to connect the LV supplemental system to the applicator in a monitoring mode, the applicator comprising one or more ablation electrodes and a plurality of mapping / sensing electrodes; a second one or more relays configured to connect a pulse generator to the applicator in the pulsing mode and to electrically isolate the pulse generator from the applicator and the LV supplemental system in the monitoring mode; a differential input signal protection circuit configured to limit a voltage between the plurality of mapping / sensing electrodes of the applicator to less than a differential voltage threshold; and a controller configured to switch between the pulsing mode and the monitoring mode. These isolation apparatuses may include any of the features described above.

[0027] The differential voltage threshold may be about 12V (about 14V, about 16V, about 18V, about 20V, about 22V, about 24V, about 26V, about 28V, about 30V, about 32V, about 34V, about 36V, about 38V, about 40V, between about 10-40V, between about 15-30V, between about 18-30V, between about 20-30V, etc.). The differential signal protection circuit may comprise a plurality of bidirectional protection circuits or circuit components (e.g., diodes) that may be coupled, for example, from each of electrode or sensor input signal lines to a hub and the plurality of bidirectional protection circuits or circuit components from the hub to earth ground having a higher voltage rating than each protection diode of the plurality of bidirectional protection circuits or circuit components.

[0028] The apparatus may include an earth ground switch configured to disconnect the one or more LV supplemental systems from an earth ground in the LV mode and to connect the one or more LV supplemental systems to the earth ground in the HV mode.-9 - 14567-738.600 / 135 PCT

[0029] Also described herein are methods of operating any of these apparatuses. For example described herein are methods of protecting a low voltage (LV) supplemental system coupled to a first applicator during the application of high voltage energy from the first applicator and / or a second applicator (which may be positioned proximate to the first applicator within or on a patient), the method comprising: switching between a high voltage (HV) treatment mode during which a high voltage (HV) treatment system is connected to the first applicator and / or second applicator and the LV supplemental system is isolated from the first and / or second applicator and a monitoring mode during which the HV treatment system is isolated from first and / or second applicator and the LV supplemental system is coupled to the first and / or second applicator; detecting, in an isolator state detection circuit (e.g., a relay state detection circuit), in real time, a state of a first one or more relays configured to electrically isolate the LV supplemental system from the first and / or second applicator in the HV treatment mode and to connect the LV supplemental system to the first and / or second applicator in the monitoring mode, and outputting the state; detecting, in the isolator state detection circuit, in real time, a state of a second one or more relays configured to connect the HV treatment system to the first and / or second applicator in the HV treatment mode and to electrically isolate the pulse generator from the first and / or second applicator in the monitoring mode, and outputting the state; and performing a failure detection check by comparing the outputs of the isolator state detection circuit with an expected output.

[0030] As mentioned, in any of these methods and apparatuses the same applicator may be used for both the HV treatment and the LV detection. For example, described herein are methods of operating any of these apparatuses. For example described herein are methods of protecting a low voltage (LV) supplemental system coupled to an applicator during the application of high voltage energy to the applicator, the method comprising: switching between a high voltage (HV) treatment mode during which a high voltage (HV) treatment system is connected to the applicator and the LV supplemental system is isolated from the applicator and a monitoring mode during which the HV treatment system is isolated from applicator and the LV supplemental system is coupled to the applicator; detecting, in an isolator state detection circuit (e.g., a relay state detection circuit), in real time, a state of a first one or more relays configured to electrically isolate the LV supplemental system from the applicator in the HV treatment mode and to connect the LV supplemental system to the applicator in the monitoring mode, and outputting the state; detecting, in the isolator state detection circuit, in real time, a state of a second one or more relays configured to connect the HV treatment system to the applicator in the HV treatment mode and to electrically isolate the pulse generator from the applicator in the monitoring mode, and outputting the state; and - 10 - 14567-738.600 / 135 PCTperforming a failure detection check by comparing the outputs of the isolator state detection circuit with an expected output.

[0031] Any of these methods may include triggering a safe mode (which may be a mode different from either HV treatment mode or monitoring mode) or a shutdown if the failure detection check indicates a mismatch between the outputs of the isolator state detection circuit and the expected output.

[0032] For example, a method of protecting a low voltage (LV) supplemental system coupled to an applicator during an application of high voltage energy to the applicator may include: switching an isolation apparatus between a high voltage (HV) treatment mode and a monitoring mode, wherein the isolation apparatus is coupled to each of the LV supplemental system, the applicator and a HV treatment system; electrically isolating the LV supplemental system from the applicator and from the HV treatment system during the HV treatment mode using a first one or more relays configured to electrically isolate the LV supplemental system from the applicator in the HV treatment mode and to connect the LV supplemental system to the applicator in the monitoring mode; electrically isolating the HV treatment system from the applicator and from the LV supplemental system during the monitoring mode using a second one or more relays configured to connect the HV treatment system to the applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator in the monitoring mode; and electrically isolating an activation coil of the second one or more relays using one or more galvanic isolators (e.g., a high voltage / low-capacitance isolator).

[0033] A method of protecting a low voltage (LV) supplemental system coupled to an applicator during an application of high voltage energy to the applicator, wherein the applicator comprises a plurality of mapping / sensing electrodes, may include: switching an isolation apparatus between a pulsing (e.g., high voltage) mode and a monitoring mode, wherein the isolation apparatus is coupled to each of: the LV supplemental system, the applicator and a pulse generator or a high voltage (HV) system; electrically isolating the LV supplemental system from the applicator and from the pulse generator during the pulsing mode using a first one or more relays configured to electrically isolate the LV supplemental system from the applicator in the pulsing mode and to connect the LV supplemental system to the applicator in the monitoring mode; electrically isolating the pulse generator from the applicator and from the LV supplemental system during the monitoring mode using a second one or more relays configured to connect the pulse generator to the applicator in the pulsing mode and to electrically isolate the pulse generator from the applicator in the monitoring- 11 - 14567-738.600 / 135 PCTmode; and limiting a voltage drop between the plurality of mapping / sensing electrodes of the applicator to less than a differential voltage threshold.

[0034] The differential voltage threshold may be about 12V (about 14V, about 16V, about 18V, about 20V, about 22V, about 24V, about 26V, about 28V, about 30V, about 32V, about 34V, about 36V, about 38V, about 40V, between about 10-40V, between about 15-30V, between about 18-30V, between about 20-30V, etc.). The voltage drop may be limited by a plurality of bidirectional protection circuits or circuit components that are coupled in parallel to a hub and the plurality of bidirectional protection circuits or circuit components having a higher voltage rating than each bidirectional protection circuit or circuit component of the plurality of bidirectional protection circuits or circuit components.

[0035] Also further described herein are isolation apparatuses, wherein the apparatus may comprise: a first one or more relays configured to electrically isolate a low voltage supplemental system from one or more monitoring / sensing electrodes of the LV supplemental system in a high voltage (HV) treatment mode and to connect the LV supplemental system to the one or more monitoring / sensing electrodes in a monitoring mode; a second one or more relays configured to connect a high voltage (HV) treatment system to a high voltage applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator in the monitoring mode; a controller configured to switch between the HV treatment mode and the monitoring mode; and an earth ground switch configured to disconnect the signal line protection devices from an earth ground in the monitoring mode and to connect the signal line protection device to the earth ground in the pulsing mode. The HV treatment system may comprise a pulse generator and the pulsing / HV treatment mode may comprise an ablation.

[0036] In any of the methods and apparatuses described herein, unless specified otherwise, the electrodes of the low voltage supplemental system, e.g., low voltage (e.g., monitoring / sensing) electrodes, may be a part of the same applicator as the high voltage electrodes of the high voltage system (e.g., pulse generator). For example, an isolation apparatus may be a part of a system comprising the pulse generator and the applicator, and wherein the applicator comprises one or more ablation electrodes and a plurality of monitoring and / or sensing electrodes. Alternatively, any of these methods and apparatuses, including the isolation apparatuses, may be used with multiple applicators, including the applicator configured to apply the high voltage energy and one or more separate applicators including the low voltage electrodes or sensors.

[0037] Any of these apparatuses may include a relay state detection circuit configured to continuously detect, in real time, a state of the first one or more relays and a state of the - 12 - 14567-738.600 / 135 PCTsecond one or more relays in respective HV treatment (pulsing) mode and monitoring mode, wherein the controller is further configured to: receive an output from the relay state detection circuit, and to compare the output from the relay state detection circuit with an expected output to perform failure detection of the first or the second one or more relays. Any of these apparatuses may include a plurality of ports configured to couple to a plurality of cables for connection to the supplemental system, the applicator and / or the pulse generator. The supplemental system may comprise at least one of a sensing system, a mapping system, a position tracking / navigation system and / or a pacing system. In any of these apparatuses, the isolation apparatus may be configured to transmit pulses up to 50kV from the pulse generator to the applicator in the pulsing mode. In general, these apparatuses may be configured to receive electric pulses in microsecond and sub-microsecond ranges.

[0038] In any of these apparatuses, the applicator may comprise an electromagnetic (EM) sensor. The applicator may comprise one or more electrodes configured to be in electrical communication with both the low voltage supplemental system in the monitoring mode and with the high voltage treatment system (e.g., pulse generator) in the high voltage treatment (pulsing) mode. The relay state detection circuit may be isolated from the first and / or the second one or more relays by an opto-isolator or by one or more high frequency / low capacitance isolators. The first one or more relays may be configured to shunt current to ground when a high voltage is applied. In general, connections to the low voltage supplemental system may be protected by circuits or devices that protect the LV system when the voltage (e.g., the voltage being applied to the patient) is greater than a threshold, for example, greater than 300V, or greater than 375 V, etc. In any of these apparatuses the second one or more relays (e.g., relay drive circuit) may itself be electrically isolated entirely by one or more high frequency / low capacitance isolators. The second one or more relays may be a low voltage power relay. Any of these apparatuses may include a plurality of protection components, such as transient voltage suppression diodes, gas discharge tubes, metal-oxide varistors or similar protection circuitry. Such bidirectional protection circuits or circuit components (e.g., diodes) may be connected to the low voltage supplemental system signal lines. The second one or more relays may be configured to withstand up to 1400 A, for example, under arc conditions at 15kV pulse voltage.

[0039] All of the methods and apparatuses described herein, in any combination, are herein contemplated and can be used to achieve the benefits as described herein.- 13 - 14567-738.600 / 135 PCTBRIEF DESCRIPTION OF THE DRAWINGS

[0040] A better understanding of the features and advantages of the methods and apparatuses described herein will be obtained by reference to the following detailed description that sets forth illustrative embodiments, and the accompanying drawings of which:

[0041] FIG. 1 A schematically illustrates an example of an isolation apparatus, shown as part of an overall interconnected system.

[0042] FIG. IB schematically illustrates another example of an overall interconnect diagram for a system including an isolation apparatus.

[0043] FIG. 2A illustrates one example of an isolation apparatus, shown connected to an applicator configured as a catheter for the application of ablation energy, electrical mapping, and position sensing, a pulse generator (console) and a mapping system.

[0044] FIG. 2B is an enlarged view of the isolation apparatus of FIG. 2A.

[0045] FIG. 3 illustrates one example of a user interface for a system including or coupled to an isolation apparatus.

[0046] FIGS. 4A-4B illustrate one example of an applicator configured for both sensing position and / or mapping as well as the application of ablation energy. FIG. 4A shows a distal end view of the applicator and FIG. 4B shows a side view of the distal end region of the applicator.

[0047] FIGS. 5 and 6 schematically illustrate operation of the isolation apparatus in pulsing mode (FIG. 5) and monitoring mode (FIG. 6).

[0048] FIG. 7 is a schematic illustration of one example of an electrical architecture (e.g., block diagram) of an isolation apparatus.

[0049] FIG. 8 schematically illustrates an example of an isolator state detection circuit that is configured as a relay state detection circuit to perform continuous, real-time, detection of the state of the isolator (e.g., relay).

[0050] FIG. 9 schematically illustrates an example of an isolated relay assembly that may be used in any of the isolation apparatuses described herein.

[0051] FIG. 10 schematically illustrates one example of an overvoltage protection assembly that may be included as part of an isolation apparatus.

[0052] FIG. 11 schematically illustrates one example of an isolation diagram illustrating various isolation zones within an isolation apparatus.

[0053] FIGS. 12A-12B schematically illustrate one example of an earth ground switch configured to disconnect one or more low voltage systems from earth ground when the- 14 - 14567-738.600 / 135 PCTisolation apparatus is not in the HV (e.g., pulsing) mode. FIG. 12A schematically illustrates the configuration in the low voltage (monitoring) mode, mitigating coupling from an external high voltage (e.g., defibrillation) source to the LV supplemental systems. FIG. 12B schematically illustrates the configuration in the high voltage (pulsing) mode, mitigating any coupling from the HV treatment outputs to the LV supplemental systems.DETAILED DESCRIPTION

[0054] Apparatuses and methods for electrically isolating low voltage equipment from the high voltage equipment used during medical procedures are provided. The isolation apparatuses and methods described herein may be particularly helpful when used with a high voltage (HV) pulse generator, such as (but not limited to) a microsecond and / or submicrosecond pulse generators, which may be low impedance pulse generators. Such systems (see, e.g., US 2021 / 0196375) may operate at relatively high working voltages (e.g., voltages greater than about 500V, 1 kV, 5kV, lOkV, 15kV, 25kV, etc.). The low voltage systems, also referred to herein as supplemental systems or low voltage (LV) supplemental systems may be used on the same patients and may optionally share the same applicator. Any appropriate low voltage system may be used, in particular monitoring (e.g., mapping and / or sensing) systems, pulse oximeters systems (e.g., configured to measure SpCh and pulse rate), bispectral index (BIS) monitoring systems, or blood pressure sensor systems, electrocardiography (ECG), electroencephalography (EEG) systems, electromyography (EMG) systems, cardiac pacemaker systems, tissue / clot sensing (e.g., bioimpedance) systems, etc.

[0055] The isolation apparatuses described herein may utilize one or more low-cost power relays to effectively isolate high voltage and high-current pulses from supplemental systems that are connected to the same applicator. These supplemental systems may even share common electrodes with the high voltage components, such a pulse generator. A high degree of isolation is critical to prevent interference or damage. In certain configurations, this isolation may be achieved by “floating” or electrically isolating the entire relay, ensuring that no high voltage potential is present across any part of the relay. This design approach helps protect sensitive components and allows the apparatus to operate safely without risk of electrical shock or system malfunction due to inadvertent voltage surges such as arcing.

[0056] The isolation methods and apparatuses described herein may incorporate detection circuits that may themselves be isolated and are configured to monitor the state of the isolators (e.g., relays), providing real-time feedback on the operational state of the isolator. This direct monitoring ensures that the high voltage components, such as the pulse generator, are fully isolated from the supplemental systems and helps to ensure proper functioning - 15 - 14567-738.600 / 135 PCTduring operation. The use of these detection circuits enhances the safety and reliability of the system by allowing immediate identification and remediation of any potential issues with the relay's performance.

[0057] The isolation apparatuses may be configured to cold-switch all relays within the system. Cold-switching refers to the process of switching the relays to their desired state while they are not under a load, meaning no electrical current is flowing through the relay contacts at the time of switching. This approach allows the system to set the relays to their target state before any HV treatment is output from a generator or any other HV treatment system. By ensuring the relays are in the correct position prior to HV or high current activation, stress on the relays during operation may be minimized. As a result, the system can utilize smaller relays, which are more cost-effective and energy-efficient, while still maintaining performance standards. Moreover, this cold-switching technique significantly extends the service life of the relays by reducing wear and tear from frequent switching under load conditions, contributing to more reliable and durable system operation over time.

[0058] The isolation apparatuses described herein are especially useful with applicators comprising a treatment / ablation electrodes and also sensing / mapping / navigation electrodes, which are configured to connect to high voltage pulse generators and also to low voltage (LV) supplemental systems. The supplemental system as used herein generally includes any system that connects to the applicator, typically to receive low voltage input and / or output.Supplemental systems may include, for example, one or more of mapping, sensing, tracking, navigation, and / or pacing systems. In some cases the supplemental system may sense or apply electrical energy (e.g., mapping position sensing, impedance sensing, etc.). In some cases the supplemental system may be couped to one or more inputs and / or outputs on the applicator. Supplemental systems may include sensing and / or applying energy other than electrical energy, such as ultrasound, optical, etc. For example, a supplemental system may include an optical mapping system, an imaging system, an ultrasound mapping system, etc. Typically, all of these supplemental systems may be protected from damage that may arise from the high voltage ablation system, as they may operate at low voltage (e.g., less than 500V, 400V, 300V, 200V, 150V, 100V, 80V, etc.). A supplemental system may couple to one or more inputs / outputs to the applicator and may benefit from electrical isolation from the high voltage ablation system, which may be on the same applicator and in some cases may share inputs / outputs with the ablation system.

[0059] In some examples the pulse generator system is a low impedance (LI) pulse generator. The isolation apparatus may be stand-alone or it may include one or more accessory cables, e.g., an EM sensing cable, mapping sensor cable, pulse generator cable, etc.- 16 - 14567-738.600 / 135 PCT

[0060] The isolation apparatus may be a part of an overall mapping / sensing and pulse generator system, or it may be a stand-alone device. In some cases the isolation apparatus may be integrated with either the supplemental (e.g., mapping / sensing) system or the pulse generator system. The isolation apparatus may connect to supplemental system, pulse generator and / or applicator (e.g., a catheter, a probe, etc.) via one or more cables. Thus one or more cables may be used for interconnections between the isolation apparatus and the other components, including third-party 3D electro-anatomical mapping systems, electromagnetic (EM) tracking systems, equipment that utilize the electrogram (EGM) signal, and / or other low voltage equipment useful in the diagnosis and treatment of biologic tissue. In general, the isolation apparatus enables the isolation of the sensing / mapping electrodes (e.g., EGM sensing electrodes, EM tracking electrodes, mapping electrodes) that may use Low Voltage (LV) signals from the HV signals (e.g., nanosecond or microsecond energy pulse signals, or other high voltage signals). During HV pulsing, the isolation apparatus connects the HV signal (e.g., from the pulse generator) to the ablation electrodes on the applicator and makes sure that the LV components, such as the low voltage supplemental systems (e.g., mapping / position sensing, etc.) that may also be connected to the same applicator are disconnected, e.g., isolated, from the applicator and any other portion of the system that may be in electrical communication with the pulse generator. The isolation apparatus may also ensure that during LV operation (e.g., during mapping / sensing, etc.) any HV components (e.g., the pulse generator) are completely electrically isolated, so that they may not connect to the applicator, including to the ablation electrodes (e.g., HV catheter electrodes). This may protect any LV supplemental systems, such as the sensing / mapping system, 3D electroanatomical mapping system, position (e.g., electromagnetic, EM) tracking system, etc.

[0061] By providing the isolation between the HV signal and the LV signals, the isolation apparatus provides protection to the equipment connected to the isolation apparatus from damage due to capacitive coupling (or a direct connection at the catheter electrodes) of the HV signal to the LV signals.

[0062] The isolation apparatus may communicate its state to the pulse generator (for example, a separate controller of the pulse generator) that may coordinate operation of the isolation apparatus and the pulse generator, including receiving user input and / or providing user output.

[0063] During ablation (e.g., HV pulsing) the isolation apparatus may transmit high voltage signals (e.g., microsecond electrical pulses, nanosecond electrical pulses, RF, microwave, or high-current pulses, etc.) from the generator to the applicator, enabling the effective ablation, cutting or coagulation of tissue (e.g., cardiac tissue), or physiological - 17 - 14567-738.600 / 135 PCTfluids (blood).. The isolation apparatus may transmit LV signals, e.g., from the applicator’s sensing / mapping electrodes to the sensing / mapping system (e.g., a 3D electro-anatomical mapping system, an EM tracking system, and / or other EP equipment).

[0064] The isolation apparatus may be configured as descried herein to have electrical characteristics (e.g. dielectric withstand, impedance, EMC) to ensure safe and effective HV energy transfer from the pulse generator to the applicator(s) while simultaneously protecting (i.e., isolating) the supplemental system (e.g., 3D electro-anatomical mapping, EM sensing systems, etc.) from HV energy that may cause equipment damage.

[0065] In any of these methods and apparatuses described herein, the cabling and connectors may be keyed to avoid incorrect connections.

[0066] The isolation apparatus may also be keyed and / or may include software, hardware and / or firmware to permit only a predetermined applicator for use with the isolation apparatus and / or with the pulse generator.

[0067] FIG. 1 A schematically illustrates one example of an overall interconnect diagram, including an isolation apparatus 150 that is configured to act as an interface between one or more applicators 120, 124, a low voltage supplemental system 200, and a pulse generator 100. In any of the methods and apparatuses described herein, the same applicator may be used for the high voltage (e.g., pulsed ablation) system and the low voltage (e.g., supplemental) system. The applicator 120 may be, for example, a catheter, such as a catheter with an EM sensor. In this example the isolation apparatus is a stand-alone device that may be used in conjunction with supplemental system 200 and pulse generator system 100. The supplemental system 200 may be, e.g., a 3D electro-anatomical mapping system. The high voltage system 100 may include a pulse generator having a low-impedance console. The pulse generator may include a display 105 and may provide a user input and / or output for controlling the system. In FIG. lAthe display 105 shows a user interface (e.g., graphical user interface). When connected to the pulse generator, the isolation apparatus 150 may initialize the appropriate treatment parameters when the applicator 120 is connected. The pulse generator may be configured to apply high voltage, microsecond, or sub-microsecond (e.g., nanosecond) pulses for performing ablation of a target tissue. The applicator 120 may be configured to deliver the pulsed energy (e.g., bipolar pulsed energy) through the tissue between two or more electrodes, e.g., to treat tissue, for example, cardiac tissue. The supplemental system 200 may be coupled to the isolation apparatus via one or more cables, e.g., mapping (“EGM”) cable 160 or sensing (“EM”) cable 170 to allow the supplemental system 200 to provide mapping, sensing and / or navigation information. In variations in which a single applicator is used for both the high voltage and low voltage systems the applicator - 18 - 14567-738.600 / 135 PCT120 may be connected to the isolation apparatus 150 by one or more cables, such as a sensing cable 130 and a catheter extension cable 140. The isolation apparatus 150 may also be connected to the pulse generator 100 by one or more cables 110 (e.g., a console cable). FIG.1 A also indicates the optional configuration in which separate applicators are used for the high voltage system and the low voltage system. In FIG. 1 A a second applicator 124 is shown connected to the sensing able 130’; in this configuration the sensing cable 130 may not connect to the first applicator 120. Optionally in some examples the low voltage (supplemental) system may connect to both applicators via multiple cables 130, 130’. In some examples the second applicator may be entirely configured for sensing (e.g., electrical sensing) and may not, strictly speaking apply energy. Both the first and second applicators (when used) may be configured as one or more of catheters, probes, coils, pads, plates, wires, etc. and may include one (or preferably more) electrodes, including arrays of electrodes. The first and second applicators may have different forms factors (e.g., the first applicator may be a catheter and the second applicator may be a wire, etc.).

[0068] FIG. IB is a schematic of another example of an overall interconnect diagram, including an isolation apparatus 150 that is coupled to a pulse generator 100, an applicator 120 (e.g., catheter) including both ablation and sensing / mapping electrodes, a mapping system 200 (e.g., cardiac electrophysiology system) and an EM location sensing system 200’ (e.g., EM position sensing or tracking system).

[0069] FIG. 2A illustrates another example of an overall interconnection, including an isolation apparatus 150 (shown in greater detail in FIG. 2B) that is configured to act as an interface between the applicator (e.g., a catheter) 120, a mapping system 200, and a pulse generator 100. When the ablation electrodes of the applicator 120 are connected to the pulse generator 100, the isolation apparatus 150 may initialize the appropriate treatment parameters for delivery through the applicator. In some cases the pulse generator is configured to apply high voltage, microsecond, or sub-microsecond (e.g., nanosecond) pulses for performing ablation. Any appropriate applicator 120 may be used and configured to deliver the pulsed energy (e.g., bipolar pulsed energy) through the tissue between two or more treatment / ablation electrodes, e.g., to cardiac tissue during cardiac procedures or other target tissue, as appropriate. The same applicator may include both mapping / sensing and / or ablation electrodes. The supplemental system 200 (e.g., mapping system) may be coupled to the isolation apparatus 150 via one or more cables (such as cables 160, 170) to allow the supplemental system 200 to provide mapping and / or navigation information.

[0070] In one example, a power cable may be connected to the isolation apparatus 150 (not shown in FIGS. 2A or 2B), and plugged, e.g., into a wall power having a protective - 19 - 14567-738.600 / 135 PCTground. The isolation apparatus may be connected to room equipotential grounding. The isolation apparatus may include a power switch that may be toggled between the off and on configuration. The isolation apparatus may then be connected to the pulse generator 100. For example, a cable (e.g., console cable 110) may be connected to the port 155 (see FIG. 2B) on the isolation apparatus, and the same cable may be connected to the pulse generator 100, as shown. The applicator (e.g., catheter 120) may be connected via one or more cables, such as a sensing cable 130 and a catheter cable 140, to the isolation apparatus 150. In FIGS. 2A-2B, the applicator is connected via the sensing cable 130 to an applicator (e.g., catheter) cable port 153. The isolation apparatus may include additional port 154 for connecting additional applicator (e.g., catheter) cables (e.g., cable 140). The isolation apparatus may also be connected to the mapping / sensing system 200 by one or more cables (e.g., mapping and EM sensing cables 160, 170) connecting to ports 152, 151 on the isolation apparatus, as shown. The dimensions for the isolation apparatus shown in FIG. 2B are but one example of such dimensions. The actual dimensions may be different, including smaller, or larger. As mentioned above, in some examples the isolation apparatus may be integrated with the pulse generator 100 or other components, such as the supplemental system 200.

[0071] The apparatuses (e.g., systems and devices) described herein, including the isolation apparatuses, may include any appropriate inputs / outputs. For example, the apparatus may include an input from one or more of a button, switch, toggle, lever, slider, foot switch, touchscreen, etc. The output may be visual (display screen, LED, projection, etc.), audible (tone, speech, etc.), tactile, etc.

[0072] An isolation apparatus may include a controller that coordinates the switching between a high voltage treatment mode, referred to herein as a “pulsing” mode (although this mode is not limited to “pulsing” but rather intended to cover any high voltage treatment mode), and a low voltage mode, referred to herein for convenience as a “monitoring” (or sometimes “mapping” mode, although this mode is not limited to mapping); in the pulsing mode the isolation apparatus connects the applicator to the high voltage system, such as a pulse generator, and isolates the low voltage supplemental systems, while in the monitoring mode the isolation apparatus connects the applicator to the supplemental systems, and fully isolates the high voltage (e.g. pulse generator) systems. The isolation apparatus switches between these modes and continuously (by polling at a predetermined or adjustable frequency of, e.g., equal or greater than 10 Hz, 50 Hz, 100 Hz, 200Hz, 300 Hz, 500 Hz, 750 Hz, 1kHz, 1.5 kHz, etc.) monitor the state of the isolation of the high voltage system(s), e.g., pulse generator, and the low voltage supplemental system(s). The isolation apparatus controller may include software, hardware and / or firmware, including one or more processors, e.g.,-20 - 14567-738.600 / 135 PCTmicroprocessors, memory and control logic. For example, the isolation apparatus controller may receive and compare data from the one or more, e.g., plurality of, state detection circuits (which may be also referred to generally as “isolation state detection circuits,” or as “relay state detection circuits”) that monitor the state of the isolators, such as the state of the one or more relays, optoisolators, high voltage / low-capacitance isolators, etc. (e.g., galvanic isolators), and may compare these states to a predetermined or expected state based on the mode (e.g., pulsing mode, monitoring mode, etc.) that the isolation apparatus is operating in. The isolation apparatus controller may be linked to the controller for the pulse generator (e.g., console) and / or the controller(s) for the supplemental system(s) and may set the operational mode based on input from one or more user inputs from the isolation apparatus, and / or on the pulse generator (e.g., console) and / or from the supplemental system(s). The isolation apparatus controller may be linked to the isolators to control the state (e.g., open / isolating, closed / non-isolating, etc.) of each isolator based on the operating mode, and / or based on detection of a fault or mismatch between the expected state corresponding to the operation state and the state(s) determined by the state detection circuit(s). Thus, the isolation apparatus controller may control the relays (switches) within the isolation apparatus.

[0073] The isolation apparatuses described herein may include a communication control interface for communicating with the pulse generator / console and / or with the supplemental system(s). In general, the isolation apparatus may act as an intermediary between the pulse generator and supplemental system(s) and the applicator and may replace direct connections between these components. Thus, the isolation apparatus may include one or more inputs corresponding to each supplemental system and the pulse generator. As mentioned, the isolation apparatus may be configured to couple with virtually any supplemental system, including but not limited to mapping systems that use electrical sensing from one or more electrodes on the applicator (which may be separate but intermixed with ablation electrodes or may include the ablation electrodes), such as an intracardiac electrogram mapping (EGM) system. The isolation apparatus may couple with an electromagnetic (EM) tracking interface for tracking the position and / or orientation of the applicator based on an EM sensor in the applicator. Other supplemental systems may include ultrasound systems (e.g., ultrasound mapping and / or ablation systems) that may include one or more ultrasound transducers on the applicator, and / or one or more optical systems, which may include one or more optoelectric components on the applicator (e.g., LEDs, etc.).

[0074] In some examples, once the isolation apparatus is powered on and connected to the pulse generator, a display 105 of the pulse generator (or a display of any other component) may display a user interface (e.g., video, touchscreen, etc.). In some cases the -21 - 14567-738.600 / 135 PCTuser interface may display a screen including an image of the isolation with one or more prompts to guide a user in connecting the applicator / catheter and / or mapping system. During or before the start of a procedure, the user interface may display a procedure screen, as shown by example in FIG. 3. In this example, the user interface may include data about the system and / or procedures being performed, such as an image of the isolation apparatus 112, the date / time, the image 106 of the configuration of the applicator, a session type and / or indicator 108 (e.g., number, name, etc.). The user interface may also include an identifier for the user or users (e.g., a name, identification number, etc.). The user interface may also guide the user in selecting the treatment levels, etc.. Guidance may be graphical and / or textural, and may be displayed on the user interface, e.g., screen, such as a touchscreen.

[0075] As mentioned above, any appropriate applicator may be used, including a single applicator with both sensing and / or mapping and ablation electrodes, or plurality of applicators with different sensing and ablation electrodes. FIGS. 4A and 4B illustrate one example of an applicator that may be used. For example, in FIG. 4Athe distal end of the applicator, which may be expandable, includes a plurality of discrete sensing (e.g., mapping) electrodes 431. In this example, ten are shown on the arms of the distal-facing applicator. Wire ablation electrodes 432, 433 are connected between these arms. The wires forming the individual petals of the inner ring / electrode (extending between adjacent arms) may be electrically connected; separately the wires forming the individual petals of the outer ring / electrode may be also electrically connected. The distal end may be collapsable and expandable. FIG. 4B shows a side view of the same applicator as in FIG. 4A, showing an additional set of sensing electrodes on the shaft of the applicator. The sensing electrodes on the shaft and on the arms of the applicator may be ring electrodes. An electromagnetic (EM) sensor 435 may also be held within the distal end region of the shaft, as shown.

[0076] The methods and apparatuses described herein may be used, and / or may include, applicators in which the same electrodes, or a subset of the same electrodes, are used for both ablation (high voltage energy) and mapping / sensing (e.g., low voltage energy). Alternatively or additionally, in some implementations, the ablation electrodes and the mapping electrodes may be close to each other, e.g., less than 5 mm, less than 4 mm, less than 3 mm, less than 2 mm, etc.). In both cases, this may provide a significant risk of damage to the low voltage supplemental systems without the isolation apparatuses described herein.Operation of the isolation apparatus

[0077] As mentioned, the isolation apparatuses described herein have two primary operating modes, a low voltage monitoring mode (e.g., “sensing” or “mapping”) and a high voltage treatment mode (e.g., “ablating”, “pulsing”, or any HV treatment delivery). The term -22 - 14567-738.600 / 135 PCTmonitoring mode, as used herein, is intended to cover any one or a combination of the modes of operation during which the low voltage supplemental system is connected to a patient and used for sensing, mapping, pacing, tracking or navigation, or any other form of monitoring; the monitoring mode may also therefore be referred to as a ‘low voltage mode’. In some specific examples, the monitoring mode may also be referred to as a mapping mode.Similarly, the pulsing mode may refer to any one or a combination of modes of operation during which the high voltage system is applying high voltage signal (e.g., voltage greater than 0.5Kv). As stated earlier, the “pulsing mode” is not limited to pulsing but rather is intended to cover any high voltage treatment delivery, including in some cases for therapeutic treatment, such as ablation. The pulsing mode may, therefore, be referred to generically as a “high voltage treatment mode” and may refer to delivery of any high voltage energy, particularly high voltage energy for patient treatment. The isolation apparatus may include a configuration of relay banks (switches) and system level connections for each of these modes, such as the configurations schematically illustrated in FIGS. 5 and 6. One example of an electrical architecture (e.g., block diagram) of an isolation apparatus is provided in FIG. 7. FIGS. 5 and 6 illustrate high-level descriptions of the expected states of the high voltage systems (pulse generator / console) and the low voltage supplemental systems (e.g., mapping system(s), position tracking systems(s), etc.). These states may be implemented by a one or more isolators configured specifically and beneficially as described in greater detail herein, and may be controlled and monitored by one or more sensing circuits such as an isolator state detection circuit (which may also be referred to as a relay state detection circuit).

[0078] As shown in FIG. 5, in the pulsing mode the isolation apparatus 550 is configured so that the pulse generator (for HV pulsing) is connected to the applicator (e.g., a catheter having both HV and LV electrodes) by closing a relay. The isolation apparatus is configured so that the LV (supplemental system) and HV (pulse generator) are linked in parallel by two (or more) relays. In FIG. 5 these relays, examples of which are provided below, may be configured to maintain electrical isolation between the HV and LV components. A different relay of the isolation apparatus is opened preventing electrical communication between the LV supplemental system (e.g., a sensing / mapping and / or tracking and navigation) and applicator. In the monitoring mode, shown in FIG. 6, the isolation apparatus is configured so that the pulse generator is disconnected from the applicator, as the relay between the HV pulse generator and the applicator is opened, while the relay between the LV supplemental system and the applicator is closed.

[0079] FIG. 7 shows a schematic illustration of one example of an isolation apparatus 600. In this schematic, the isolation apparatus includes a plurality of connectors for receiving -23 - 14567-738.600 / 135 PCTa cable connection from the HV system 675 (e.g., ablation console, including the pulse generator), which divides the HV signal into a HV+ and HV- signal, that are passed to HV+ 615 and HV- 616 relays, respectively. These relays may be assemblies including relays, and may themselves be isolated (e.g., so that the power and control line from the isolation apparatus controller is protected), as described in detail below. When the HV+ and HV- relays 615, 616 are closed, allowing the passing of the signal, the HV+ and HV- signals are transmitted to the applicator (e.g., to the pulse connector 654 for the applicator, such as a catheter 620). In parallel, the isolation apparatus may include one or more connections 651, 652 to / from a supplemental system, such as, in this example, a sensing / mapping system (“mapping syst”) and a position / orientation sensing system (e.g., “EM sys”). These connections may be isolated by one or more isolators (e.g., relays) for isolating the signals. FIG. 7 shows a plurality of mapping relays 655, 656 and EM system interface and relays 665 for the EM sensor signals. The EM sensor signals are delivered from the catheter sensing / mapping connector 653 to the EM system interface and relays 665, and the mapping electrode EGM signals are delivered from the catheter sensing / mapping connector 653 to the plurality of mapping relays 655, 656.

[0080] The isolation apparatus includes a controller 644 which may include a microcontroller 645 and control circuitry for power control and distribution 646. The controller may include and / or access a datastore including expected state values for the isolators in each of the operating states (e.g., pulsing, mapping, etc.). The controller 644 may also control the distribution of power from the power supply 641, which may be plugged into a wall (mains) and / or battery. The controller may also receive input from the relay state detection circuits, as described in detail below. The isolation apparatus may also control and communicate with a wireless (e.g., near-field) communication portion of the circuit for wirelessly communicating with the applicator, supplemental system and / or pulse generator / console. The isolation apparatus may include a communication, master control interface and near field communication (NFC) circuitry for reading information from the applicator.

[0081] As mentioned, the isolation apparatus may be a part of a system for operating an applicator (e.g., a cardiac catheter system). The isolation apparatus may include one or more cables for interconnections between the isolation apparatus, the applicator(s), the pulse generator and a supplemental system, e.g., a 3D electro-anatomical mapping system, an EM tracking system, or any other low voltage medical equipment that communicates with the applicator. The isolation apparatus may be sterilizable (e.g., configured for use within the-24 - 14567-738.600 / 135 PCTsterile field) or may be used outside of the sterile field. In some cases the isolation apparatus may include a sterile drape or cover.

[0082] The isolation apparatus may include power isolation for isolation and distribution of power to internal components (e.g., isolators, such as relays, circuits, etc.).

[0083] In general, any of the isolation apparatuses described herein may provide overvoltage protection, e.g., for the mapping / sensing systems described herein. For example, the overvoltage protected inputs and outputs of the supplemental system(s) may connect to mapping / sensing electrodes and / or an EM sensor on the applicator. This is described in greater detail in reference to FIG. 10. The isolation apparatus may therefore protect any supplemental system, such as a mapping and / or EM (e.g., position sensing) system(s), from damaging voltages while meeting rigorous safety and performance standards, such as 60601-1 Type CF Patient Leakage compliance testing. The isolation apparatus may include protection components, including isolators, connected at one end to the circuits or systems to be protected and at the other end to earth ground. Thus, if a voltage in the system, including on any sense lines (e.g., from the applicator) is greater than this trigger threshold voltage (e.g., about 375V) the protection components may shunt the current on the circuit or signal lines to earth ground. If such shunting were not present, high or very high voltages could arc across the circuits, arc across the sense lines, or otherwise rise to a level that could damage the sensitive, low voltage supplemental systems. The trigger threshold voltage (also referred to as the activation voltage) may be preset or may be adjusted. Testing for Type CF Patient Leakage may be conducted at 264VAC (this is an RMS, “root of the mean squared”, voltage) and so has a peak voltage of 264 • 2 = 264 • 1.414 = 373.4V.

[0084] In general the isolation components described herein may have a low capacitance, as passing Type CF for normal condition typically requires < lOuA and in fault conditions < 50uA. Most of the leakage current in a medical device may be due to capacitive coupling to the mains, so the isolation apparatus may have a voltage trigger threshold (trigger threshold) that is sufficiently low so as to protect the supplemental systems, but which may also be high enough not to fail Type CF testing.

[0085] Any of these isolation apparatuses may be configured to use lower voltage (~ 25V) protection components to keep the supplemental systems signal to signal (not signal to ground) protected, such as limiting the voltage between mapping sensor to sensor signals so that they never exceed a few volts, hence ~ 25 V protection may ensure that the signal input to signal input voltage (e.g., voltage that the low voltage supplemental systems, such as mapping and EM inputs, may be the least protected from) does not become destructive.-25 - 14567-738.600 / 135 PCT

[0086] As mentioned, any of the isolation apparatuses described herein may be configured to include continuous detection of the state of the isolators, including the isolation relays (e.g., switches). For example, the isolation apparatuses may include a state detection circuit (which, for convenience, may be referred to as “relay state detection circuit”) for all or a subset of the isolators. These state detection circuits may be used to determine if an isolator has failed (e.g., if the isolator is not in the correct or expected state based on the current operating mode as determined by the controller). Thus, the isolation apparatuses may be configured to check in real-time, e.g., by ongoing polling of the state detection circuit(s), whether there is a failed relay or failed circuit and then the isolation apparatuses may be put in a state which is safe to the patient and operator to minimize the likelihood of damage to the connected low voltage supplemental system.

[0087] Thus, the isolation apparatuses may include circuitry, e.g., state detection circuits, to perform this real-time checking of the isolators. In some cases the state detection circuits may monitor the relay contact state. The state detection circuits may be configured to withstand direct pulse voltages (e.g., at the HV system relay circuitry) and / or induced pulse voltages (e.g., at the LV system(s) relay circuitry). The state detection may be achieved using form C relays; in some cases the state detection circuits may use semiconductor switches (e.g., MOSFETs, IGBTs, etc.). The state detection circuit, which may be configured as a realtime relay state detection circuit, may ensure that the isolation apparatus delivers treatment pulses and, by detecting invalid isolator (e.g., relay) states, protects the supplemental systems such as, but not limited to, mapping and EM systems when configured for pulsing mode. Without such a state detection capability, a failed isolator (e.g., a failed relay) can cause diminished pulse voltage at the applicator electrode(s) or can cause the pulse voltage to be connected to or coupled to the isolation apparatus outputs, potentially damaging the supplemental system(s) and / or the isolation apparatus.

[0088] For example, FIG. 8 schematically illustrates an example of a state detection circuit configured to perform continuous, real-time, relay state detection. The controller of the isolation apparatus may generally accept commands from one or more inputs, such as from the pulse generator (e.g., the console of the pulse generator) and may set the mode of operation, e.g., switching between a pulsing mode and a monitoring mode based on these inputs, including in some cases based on commands from the console of the pulse generator. The isolation apparatus controller may confirm that the state of the isolators (e.g., switches / relays) is the same as intended / expected for current operation mode (e.g., HV / LV mode, such as pulsing mode or monitoring mode). If the input state from the isolator (e.g., relay) determined by the state detection circuit matches the intended / expected state for the -26 - 14567-738.600 / 135 PCTconfigured mode, then this is “normal condition” (not a failure / fault condition). If the input state from the isolator (e.g., relay) determined by the state detection circuit does not match the intended / expected state for the configured mode, then this is a “failure / fault condition.”

[0089] In some cases the resulting state determination may trigger a response. For example, the sensed condition (“normal or “fault / failure”) may be transmitted to the pulse generator (e.g., console) including any output to the user, such as a display. If the condition is failure / fault the pulse generator stops pulsing (if in HV mode) and issues an alert, such as an audible alert, and an error message on the output, such as the console screen. If in monitoring mode, the pulse generator may issue an audible alert and error message on an output (e.g., screen). In some cases the isolation apparatus may also act internally, e.g., trigger a backup disconnect from the high voltage system.

[0090] In some examples of the isolation apparatus, the state detection circuits may be coupled to the isolators, such as the one or more relays configured to isolate the high voltage system (e.g., pulse generator) during monitoring mode operation and the one or more isolators, e.g. relays, configured to isolate the low voltage supplemental system(s) (e.g., mapping or EM relays) during pulsing mode. In FIG. 8, a relay receives an input signal 771, e.g., HV+ or HV- signals for the high voltage system in the pulsing mode, or sensing signals to / from the catheter for the low voltage supplemental system during monitoring mode. This input is shared by half of the detection circuit, such as a state detection isolator 773 (e.g., a relay state detection power isolator), e.g., a high voltage mapping / EM sense relay or high voltage pulse relay detection. This isolator isolates the state detection circuit (and may be considered part of the stated detection circuit in some examples), and may be controlled by the controller of the isolation apparatus via input line 774. The state detection isolator 773 may be connected to the power common / retum 775 of the isolation apparatus (e.g., in the open state) and may couple to another relay state detection isolator 777. In FIG. 8 the relay state detection circuit include a second (relay state detection) isolator, an optical isolation component (e.g., optoisolator 777) that produces state detection output 778 (e.g., relay state detect logic output) and is also connected to the power common / return 775’ of the isolation apparatus. In FIG. 8, the state of the isolator (e.g., relay) is therefore determined in part by the optoisolator (e.g., phototransistor / photodiode). Thus, the state detection circuit may detect the state of the isolator (e.g., relay) being monitored by connecting a photodiode to the pole (in the open configuration) of the switch so that in the open state the relay pole turns on the photodiode which activates an output phototransistor. Multiple levels of isolated power and isolated relay state detection optoisolators may be cascaded. This may also reduce the-27 - 14567-738.600 / 135 PCTcoupling capacitance from the isolator (e.g., relay) to the isolation apparatus bus, ensuring effective isolation during fast high voltage treatment pulses.

[0091] The controller may determine if the isolator (e.g., relay) being checked is in the desired state (e.g., open / close) based on the expected state, and may output a normal / fail signal (e.g., the comparison may happen at the state detection circuit) or, equivalently, the state detection circuit may output a state of the isolator (e.g., relay) being monitored by the state detection circuit to the controller (e.g., on the relay state detection logic output 778) that may compare the sensed state with the target state to determine normal / fail. The isolator state detection circuits may be referred to as relay state detection circuits when the isolator being monitored is a relay. In FIG. 8, the isolator 715 being monitored by the state detection circuit is a relay and thus the state detection circuit is a relay state detection circuit 700. In this example the output of the relay 772 may be the HV+ or HV- signals for the high voltage system in the pulsing mode if the isolator is isolating the pulse generator or may be output sensed signals from the catheter for the low voltage supplemental system during monitoring mode if the isolator is isolating the supplemental system.

[0092] The configuration of the state detection circuits and controllers described herein may be particularly fast. The isolation apparatus controller may continuously monitor the state detection circuit outputs for a plurality of isolators during operation and can detect a failed relay and report and / or act on it, e.g., by communicating with the pulse generator, for example, within less than about 0.05 seconds, less than about 0.045 seconds, less than about 0.04 seconds, less than about 0.035 seconds, less than about 0.03 seconds, less than about 0.02 seconds, etc. This relay state detection technique may ensure that the relays are in the correct state before a HV pulsing treatment begin and is monitored during pulsing. This may prevent damage to the isolation apparatus and any connected low voltage supplemental systems (e.g., mapping system or EM position / orientation system).

[0093] The operation modes described herein are generally pulsing and mapping, however, other operational modes may be included, and may have corresponding target states. Other operational modes may include a turn-on mode (e.g., turning on of the system from an off state), a shut-down mode (e.g., turning off), and / or a self-testing mode, and / or an error and / or fault mode. The self-testing mode may be the same as, or part of the turn-on mode. For example, during power on, a system self-test may include confirming that the relays are all cycled to ensure that the state detection circuits are operating properly.-28 - 14567-738.600 / 135 PCTLow Cost, Board-Mounted, Pulse Signal Relay

[0094] As discussed, the isolation apparatuses described herein may include one or more isolators, e.g., relays (switches) that connect or disconnect (e.g., isolates) the applicator from the pulse generator. This one or more isolators, in pulsing mode, may provide a low contact resistance connection (when the relay is closed to conduct the treatment pulse) that can isolate, for example, the 10-20 kV HV+ and HV- signals from the rest of the isolation apparatus and can withstand, for example, up to 1400A when connected in pulsing mode. In other implementations, the one or more isolators may withstand more than 1400A.

[0095] High voltage contactors may be used in some situations to provide a high voltage, special purpose relay that is designed to isolate very high voltages (e.g., > lOkV, > 20kV) and when switched on, conducts very high currents (e.g., > 100A) while providing the high voltage isolation to the coil that energizes the relay, while providing high voltage (e.g., lOkV, 12kV, 15 kV, 18kV, etc.) isolation. However, such high voltage contactor relays have many significant disadvantages, particularly in the context of an isolation apparatuses, including their large size (often inches long and cannot be board-mounted), large weight (e.g., most weigh more than 1 lb.), high cost, and may be difficult to source due to very long lead-times.

[0096] The isolation apparatuses described herein may instead use a low voltage but high current relays in a specific isolation configuration, as shown in FIG. 9. Although the isolators for the high voltage pulse generators described herein may have very high pulse currents (e.g., up to 1400A or even higher in arc conditions) and may also need to isolate, for example, up to 30kV (in open circuit fault conditions where the reflected voltage can be up to 30kV) from the HV+ or HV- to the other circuits in the isolation apparatus, these conditions are typically only present for a very brief duration (e.g., during a 300 ns, 200 ns, 100 ns, etc. or less durations). FIG. 9 schematically illustrates an example of a low-cost relay 900 configured for use that may achieve the same results as a contactor switch. In general, these isolators are relays that are themselves electrically isolated such that the activation coil of the relay is electrically isolated by one or more high voltage, low capacitance isolators, and may include multiple levels of isolation of the activation coil. In the example shown in FIG. 9, the relay is an automative-grade relay (e.g., a 40 / 30 AMP 12V DC relay).

[0097] In FIG. 9, the isolator 900 includes a relay 901 that is configured as part of an external circuit that provides high voltage isolation (e.g., 20kV, 25kV, 30k V), and the entire relay may be isolated externally so that it may be isolated to a higher voltage than a contactor switch. In this example, the automotive relay 901 provides a low voltage (e.g., 250V, 300V, 350V, 500 V) isolation between the HV input from the pulse generator to each of the-29 - 14567-738.600 / 135 PCTapplicator (e.g., catheter), or the ground (detect +); the relay is actuated by relay coil 903. The relay coil 903 is driven by a set of isolation relays 905, 906 that are turned on in the monitoring mode, but off in the pulsing mode (each having high voltage isolation) and each also coupled to a power and signal isolator 907 (having a high voltage isolation. The isolation apparatus may connect the internal power bus to the power and signal isolation control.

[0098] Thus, the isolation apparatus described herein may isolate the pulse generator using isolators that are themselves isolated to protect the supplemental systems (and isolation apparatus) more fully. The isolation of the pulse generator during monitoring mode (or any other mode other than pulsing mode) is only required during pulsing which can, therefore, be externally isolated by using the relay for state detection rather than using a contactor-type relay that isolates the coil and contacts within the relay. Essentially, rather than using chassis mount relay (such as a contactor-type relay) that isolates the contacts and coil internal to the relay, the isolation apparatus describe herein may instead isolate the entire relay, providing the isolation external to the relays, rather than internal. Further, the low voltage but high current relay can withstand much higher than rated current (closed contact or carrying current) when the current is applied for a very short time, for example 100 ns, 200ns or 300 ns pulses. This is because the carrying current limitation of these relays is the heating of the relay contact-to-contact electrical interface and, for the systems described herein, the treatment pulses are typically short enough and the pulse rates low enough that the contact to contact interface does not heat sufficiently to cause the relay to fail.

[0099] Thus, the pulse switching circuit for the isolation apparatus described herein may use easily available, low-cost relays (e.g., 40A automative relays) with a very high voltage isolation circuit to ensure that the HV+ and HV- are very well isolated from the other systems (e.g., the circuits and wiring of the isolation apparatus and the supplemental systems). This isolator technique allows the isolation apparatus to be compact, to provide fast switching, and to have a substantially lower cost.Isolation apparatus Mapping Sense Input Differential Overvoltage Protection

[0100] The mapping (EDS) system and isolation apparatus may typically be more sensitive to differential (e.g., between sense inputs) over-voltages than to common mode (e.g., voltage from sense inputs to earth ground) at the sense signals. The isolation apparatuses described herein may be configured to ensure that, even with high voltages between the isolation apparatus mapping sense (EGM) inputs (e.g., from the applicator electrodes) there will be no more than, for example, 24V (e.g., voltage drop across two 12V bidirectional TVS diodes) between the mapping sense (EGM) inputs.-30 - 14567-738.600 / 135 PCT

[0101] FIG. 10 illustrates one example of a schematic of an overvoltage protection assembly including a star-shaped arrangement of protection diodes 1081 that may be included as part of any of the isolation apparatus for protecting the sensing / mapping system(s) (e.g., mapping / sensing / monitoring system). This configuration may be referred to as a differential input signal protection circuit. In this example the isolation apparatus may include a plurality of bidirectional protection circuits or circuit components (e.g., bidirectional TVS protection diodes) that are coupled in parallel so that each catheter mapping sense (e.g., EGM) electrode is connected to a bidirectional protection diode in the isolation apparatus; the second end of each of the bidirectional protection diodes are all connected (in parallel) to a hub comprising a higher voltage rated protection device (e.g., diode) and to an earth ground (mains ground). The hub (e.g., the second protection diode) may be a TVS (Transient Voltage Suppressor) diode or a GDT (Gas Discharge Tube) diode, a MOV (metal-oxide varistor), or any circuits that rapidly provide a low-impedance connection when the voltage across the device or circuit is above a threshold voltage. As mentioned, the sensing / mapping system and the isolation apparatus may be more sensitive to differential overvoltages (e.g., between the sense inputs for the mapping electrodes) and the arrangement of bidirectional diodes arranged in a star configuration with another diode 1083 connected to earth ground may ensure that even with high voltages between the mapping / sensing electrode inputs on the applicator (catheter) electrodes, there will be no more than a threshold voltage drop (e.g., 24V in the example shown, with 12V bidirectional TVS protection diodes) between the mapping / sensing electrode inputs. The common connection to earth ground from the 12V TVS diodes may ensure that no mapping / sense (EGM) input can have more than a second threshold, thereby protecting the isolation apparatus and mapping / sensing systems from common mode overvoltages. This arrangement may be integrated into the isolation apparatus.

[0102] In general, the isolation apparatus may include multiple isolation zones, as described above. The arrangement of these isolation zones may be particularly helpful.Isolation which is not extremely low capacitance is not helpful, as higher capacitance isolation (e.g., tens of pF from the mapping sense inputs or pulse inputs to the mapping or EM System outputs) may still transmit a significant amount of pulse current (and consequently pulse voltage) to the outputs, that is, the sensing / mapping system inputs or EM System (e.g., position sense) inputs and thereby damage the sensitive input electronics of these systems. For example, FIG. 11 illustrates one example of a schematic of isolation zones, showing the isolation circuit for input for the position sensing input from the applicator 1121, the isolation circuit for the position sensor 1123, the isolation circuit for the mapping sensor input from the applicator 1125, the isolation circuit for the output to the -31 - 14567-738.600 / 135 PCTmapping sensor system 1127, the isolation circuit for the HV input to the applicator (for ablation) 1128, the isolation circuit for the HV input from the pulse generator 1129. The schematic in FIG. 11 also shows the isolation of the communication with the controller (e.g., console) of the pulse generator 1130. The arrangement of isolation zones in FIG. 11 is just one example of extremely low capacitance isolation (e.g., less than 10 pF, less than 5 pF, less than 1 pF, etc.) between various inputs and outputs of the isolation apparatus. Without this low capacitance isolation, pulsed current, and consequently pulsed voltage, from the pulse generator may damage the isolation apparatus and supplemental system during operation of the pulse generator (which may operate at greater than 10 kV) and / or during failure conditions, such as open or arcing at or near the applicator electrodes. Thus, the isolation apparatus may include multiple very low capacitance isolation stages.

[0103] In general, the isolation apparatus described herein may include high voltage relays in the isolation apparatus that have a relay state detection circuit. That is, the isolation apparatus is configured to check, in real-time, whether there is a failed relay or failed circuit and the built-in firmware then puts the isolation apparatus in a state which is safe to the patient and the operator, and minimizes the likelihood of damage to the connected sensing / mapping systems (e.g., a mapping system and / or EM system, e.g., for catheter electrode position sensing). A detected relay or failed circuit may also cause the isolation apparatus controller to immediately communicate this failed state to the console (pulse generator), which, upon receiving the transmission, stops the high voltage treatment pulsing.

[0104] In general, the isolation apparatus described herein are configured to operate with very short pulses, e.g., microsecond, sub-microsecond / nanosecond pulses, which are particularly challenging as compared to other ablation systems, including radiofrequency (RF) ablation systems. This is because the rapid rise time of these short pulses means that the isolation between the input of the sensing systems must be isolated from the ablation pulses with an extremely low capacitance, otherwise the voltage or rise time may result in capacitive coupling (and subsequent high voltages) that may damage the sensing systems and potentially harm the patient. It is not sufficient to just isolate the sensing systems from the ablation subsystem, as the resistance may still be relatively high. Thus, the isolation apparatuses described herein are configured specifically to provide very low capacitance coupling between all the components, and particularly between the supplemental system and pulse generator to and applicator high voltage signal path.

[0105] When the isolation apparatus is in a monitoring mode the pulse generator may be disconnected from the applicator, e.g., using an isolator such as the relay assembly shown in-32 - 14567-738.600 / 135 PCTFIG. 9, and indeed, in some configurations the ablation electrode may be used as sensing electrodes when in monitoring mode. Thus, the isolation apparatus may isolate any components that will have a high voltage during pulsing (e.g., ablation), such as a voltage of greater than about 0.5 kV, 1 kV, lOkV, etc. from any circuit path that may be coupled to the lower voltage monitoring (e.g., sensing) systems. As shown in FIG. 11, there are multiple isolation barriers in series between the ground, power supply, connectors for the applicator, pulse generator and supplemental systems, to provide a very low capacitance; for example, each isolation barrier may have less than 3 pF (e.g., 2 pF, 1 pF) capacitance in series. The isolation barriers are not limited to relays, but may include relays, power supplies, optical isolators or high frequency / low capacitance isolators, and / or any low isolation capacitance galvanic isolator.

[0106] The isolation apparatus may contain overvoltage protection circuit(s) that protect the supplemental systems from voltages above a threshold voltage between about 400V-500V (e.g., 410V, 420V, etc.), while still allowing a patient leakage testing voltage (e.g., 264 VAC) to pass through and not be coupled to ground. Protection to ground will not activate until higher than the threshold voltage. Thus, the isolation apparatus may provide HV protection but not activating at a voltage that is so low that leakage current compliance is impaired.

[0107] The isolation apparatus may include a controller (e.g., microcontroller, programmable logic, firmware, hardware, etc.) that is configured to receive input from the one or more relay state detection circuits to confirm that (e.g., before switching between HV treatment / pulsing mode and monitoring mode) the relays (switches) are in the appropriate state for the current mode. The relay state detection circuits may detect a fault in the relays and may communicate to the console (pulse generator) to turn off / prevent pulsing when in pulsing mode. The state detection circuits and controller may continuously detect relay or associated circuit faults / failures while the isolation apparatus is in pulsing or monitoring mode or may turn off / prevent pulsing when in pulsing mode. The state detection circuits (e.g., fault detection circuits) described herein are configured to be very fast, so that the round-trip time to detect a fault and respond (e.g., by disabling pulsing) is extremely fast, e.g., before the next pulse.

[0108] Thus, the system may turn off pulsing when it detects out-of-normal-conditions (detected relay state or circuit fault / failure) by the next pulse (e.g., within 50 ms or less). The isolation apparatus may also have a default (e.g., unpowered) configuration such that pulsing is disabled, e.g., if there is a failure in any of the components or if power is lost. For example, the relays may be set to have a default ‘off’ state.-33 - 14567-738.600 / 135 PCT

[0109] The isolation apparatus described herein may also be configured to confirm that the applicators are compatible with the isolation apparatus. For example, the isolation apparatus may include an NFC (Near-Field Communications) reader at one or more of the applicator connectors to receive input from an NFC tag or circuit in the applicator connector that confirms the identity of the applicator.

[0110] In general, the isolation apparatuses described herein may protect the low voltage systems coupled to the same applicator delivering high voltage, e.g., ablation, energy by monitoring and controlling the isolation components (e.g. relays, opto-couplers, isolated power supplies, etc.) coupled to the applicator in defined modes, such as pulsing and monitoring modes. In the pulsing mode, all the connections between the supplemental systems are isolated from the applicator to prevent high voltage treatment pulses from damaging the sensitive low voltage inputs of the supplemental system(s), such as an electromagnetic (EM) position tracing system or electrophysiological mapping system.[oni] However, in some cases the isolation of the supplemental system may effectively disconnect and later reconnect the supplemental subsystem from the applicator, which may result in undesirable surgical procedure delays, particularly where the supplemental system is configured to initialize upon connection to an applicator by reading configuration information from the applicator. A supplemental system such as an EM position tracking system may be configured to obtain calibration and configuration data when it is connected (or reconnected) to an applicator. In some examples that EM position tracking system may read from an EEPROM (or ROM, or programable logic component, or resistor array, or any other circuit means that may contain configuration data) to obtain calibration and configuration data for the EM position tracking sensors that are part of the applicator (see, e.g., FIG. 4B). This calibration / configuration step may need to be completed before the system may operate; for example, some systems require reading EEPROM data to be completed before the EM position tracking system can be used, and may take many seconds (e.g., 5 seconds or longer).

[0112] This initial delay is not particularly significant when a supplemental system such as an EM position tracking system and / or mapping system is first connected to the applicator, as the start of a procedure that includes mapping (e.g., generating an electrophysiology map), as these systems may be connected well before placement and positioning of the applicator. However, such a delay (e.g., several to many seconds) may become burdensome after the start of the procedure. For example, in reference to the cardiac mapping, after the first ablation during which the isolation apparatus is in HV mode, cardiac mapping may be quickly performed (and may take only a few seconds, e.g., 15 to 20 seconds, for instance)-34 - 14567-738.600 / 135 PCTbefore further ablation is applied. During transitions from pulsing mode (e.g., ablating cardiac tissue) and monitoring mode (e.g., assessing the ablation effectiveness) the several second or more delay may therefore be a significant part of the time to perform the cardiac mapping that determines ablation efficacy.

[0113] To address this issue, any of the apparatuses described herein may be configured so that the isolation apparatus, after initially connecting the applicator to the supplemental system, may prevent the supplemental system from sensing disconnect caused by the isolation of the sensing system during ablation. For example, in some cases a supplemental system such as an EM position tracking system may use a “connect detect” digital signal to determine when the applicator is connected to the supplemental system. The isolation apparatus may prevent the delay due to “disconnecting” the supplemental system that may occur between the pulsing mode and the monitoring mode by continuing to present a connect detect signal to the supplemental system, continuously, even during pulsing mode when the applicator (and therefore any sensor / sensing electrodes) is isolated from the supplemental system. For example, for an EM position tracking system, the position sensor(s) and the EM Position sensor data chip (EEPROM, etc.) may be disconnected from the position tracking system during pulsing, but the isolation apparatus may transmit a signal mimicking the connect detect signal to the EM position tracking system. In general, the isolation system may signal an ongoing connection to the supplemental system even when the supplemental system is isolated from the applicator. This technique may be used with any supplemental system that reads information from the applicator when first connected.

[0114] For example, the isolation apparatus may include an applicator detect circuit to alert the isolation apparatus when a new applicator is connected. Along with this detection, if the isolation apparatus is already in, or once the isolation apparatus is changed to monitoring mode, the detection event may be forwarded to the supplemental system. This detection may stay active until the applicator is removed, regardless of the state or mode of the isolation apparatus, eliminating the surgical procedure delay that may be caused by isolation of the applicator from the supplemental system.

[0115] For example, the applicator (e.g., catheter, a clamp, a probe, etc.) may include an EEPROM (or ROM, or programable logic component, or resistor array, or any other circuit means that may contain configuration data) , such as inside the handle of the applicator, that may contain configuration data. In some cases the applicator may also include contact detection, such as by shorting two or more contacts (e.g., pins) inside the handle connector to act as a detect signal. In one example, the isolation apparatus detects the attachment to the-35 - 14567-738.600 / 135 PCTapplicator, e.g., the shorted pins, ahead of the isolation relays and transmits this signal to the isolation apparatus controller. When a detect event occurs and when the isolation apparatus is in the monitoring mode, the controller may actuate a relay that mimics the shorted pins to the supplemental system, creating a connection ‘event’, which triggers the supplemental system (e.g. EM position / orientation) to initialize based on data read from the catheter handle EEPROM. In this example, the relay will stay active for as long as the applicator is connected, regardless of the current mode of operation (e.g., pulsing mode or monitoring mode). Thus, the supplemental system may only initialize once, for the duration of time the catheter is inserted, allowing for a very quick response when the box switches to monitoring mode during a procedure. Thus, any of these isolation apparatuses described herein may detect a connection signal and may preserve the ‘initialized’ status of the supplemental system even when this system gets disconnected during isolation in the pulsing mode. This may dramatically reduce the delay after switching from the pulsing mode to the monitoring mode.Earth Ground Switch

[0116] An isolation apparatus as described herein may include a common earth ground (“mains ground”) to which the protection components for the low voltage (e.g., supplemental) systems and the high voltage (e.g. pulsing) system are attached (or conditionally attached, as described herein). Any of the isolation apparatuses described herein may include protection circuitry (such as one or more relays) to electrically isolate / protect a low voltage supplemental system. Although this may help eliminate or reduce any induced voltage in the supplemental monitoring due to capacitive or other coupling from high voltage systems / treatments, a common ground connection may in some conditions result in a leakage current and / or may be problematic when an external high voltage signal (e.g., defibrillation) is applied to the patient during the monitoring mode. The application of defibrillation (or other high voltage energy) during monitoring mode may inadvertently result in this high voltage energy being directed to the earth ground through the protection components of the supplemental monitoring system(s), for example, potentially reducing the effectiveness of the defibrillation to mitigate cardiac arrhythmia.

[0117] Thus, described herein are isolation apparatuses that include a earth ground switch that may connect the protection circuitry of the low voltage supplemental systems (e.g., transient voltage suppressors (TVSs), gas discharge tubes (GDTs), metal-oxide varistors (MO Vs) or any combination of voltage threshold activated protection components or circuits configured to electrically isolate / protect any low voltage supplemental systems during the-36 - 14567-738.600 / 135 PCTpulsing mode) to the earth ground in the pulsing mode, but may disconnect, e.g., isolate, the protection circuity from the earth ground in the monitoring mode. The earth ground switch that connects or disconnects the isolation apparatus or circuits may be activated by switching between the high voltage (pulsing) mode and the low voltage (monitoring).

[0118] Thus, in operation, the isolation apparatuses described herein may connect the protection circuitry for the low voltage supplemental systems to the earth ground in the pulsing mode and may disconnect the low voltage supplemental systems, e.g., the protection circuitry for the low voltage supplemental systems, from the earth ground in the monitoring mode. The earth ground switch may be monitored by the same state monitoring as any of the other switches in the isolation apparatus discussed above. The apparatus may therefore monitor operation of the earth ground switch in the same manner as the relays / switches described above. In the event that the earth ground switch fails, the apparatus may trigger an alert, e.g., on a console, and indicate a failure state for the isolation apparatus.

[0119] FIGS. 12A-12B illustrate an example of a portion of an isolation apparatus including an earth ground switch that may be used with any of the isolation apparatuses described herein. FIGS. 12A and 12B both schematically illustrates an example in which three sets of protection circuits 1204, 1206, 1208 are shown, however, any number of multiple sets of protection circuits may be used. For example, in the example of FIGS. 12A-12B the first protection circuit 1204 may be connected to an electromagnetic position / orientation supplemental system 1224, acting to protect the isolation apparatus output from high voltages that can be present in the pulsing mode, such as from one or more electrodes (e.g., of an applicator). The second and third protection circuits 1206, 1208 in this example are connected to another supplemental low voltage system, a mapping system, and are configured to protect EGM (e.g., cardiac electrophysiological) or other low voltage supplemental systems from high voltage that, during treatment, may be conducted to sensor signals 1226 from one or more electrodes or sensors (e.g., on the same applicator or a different applicator). All of the protection circuits 1204, 1206, 1208 are connected in parallel to the earth ground switch 1210.

[0120] FIG. 12A shows the isolation apparatus in the low voltage, monitoring, mode, and the earth ground switch 1210 is shown disconnecting these protection circuits 1204, 1206, 1208 from the common earth ground 1211. Thus, in this example, both EM and EGM signals and / or other sensor signal are connected (e.g., from a catheter or other applicator device or devices) to the respective low voltage supplemental systems, e.g., and these protection circuits are disconnected from the earth ground.-37 - 14567-738.600 / 135 PCT

[0121] FIG. 12B shows the isolation apparatus in the high voltage, pulsing, mode, (e.g., treatment mode) and the earth ground switch 1210 is shown connecting the protection circuits 1204, 1206, 1208 to the common earth ground 1211. Thus, in this example, both EM and EGM and / or other sensor signals are disconnected (e.g., from a catheter or other applicator device or devices) from the respective low voltage supplemental systems, e.g., and these protection circuits are connected to the earth ground 1211.

[0122] All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. Furthermore, it should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein and may be used to achieve the benefits described herein.

[0123] Any of the methods (including user interfaces) described herein may be implemented as software, hardware or firmware, and may be described as a non-transitory computer-readable storage medium storing a set of instructions capable of being executed by a processor (e.g., computer, tablet, smartphone, etc.), that when executed by the processor causes the processor to control perform any of the steps, including but not limited to: displaying, communicating with the user, analyzing, modifying parameters (including timing, frequency, intensity, etc.), determining, alerting, or the like. For example, any of the methods described herein may be performed, at least in part, by an apparatus including one or more processors having a memory storing a non-transitory computer-readable storage medium storing a set of instructions for the processes(s) of the method.

[0124] While various embodiments have been described and / or illustrated herein in the context of fully functional computing systems, one or more of these example embodiments may be distributed as a program product in a variety of forms, regardless of the particular type of computer-readable media used to actually carry out the distribution. The embodiments disclosed herein may also be implemented using software modules that perform certain tasks. These software modules may include script, batch, or other executable files that may be stored on a computer-readable storage medium or in a computing system. In some embodiments, these software modules may configure a computing system to perform one or more of the example embodiments disclosed herein.

[0125] As described herein, the computing devices and systems described and / or illustrated herein broadly represent any type or form of computing device or system capable-38 - 14567-738.600 / 135 PCTof executing computer-readable instructions, such as those contained within the modules described herein. In their most basic configuration, these computing device(s) may each comprise at least one memory device and at least one physical processor.

[0126] The term “memory” or “memory device,” as used herein, generally represents any type or form of volatile or non-volatile storage device or medium capable of storing data and / or computer-readable instructions. In one example, a memory device may store, load, and / or maintain one or more of the modules described herein. Examples of memory devices comprise, without limitation, Random Access Memory (RAM), Read Only Memory (ROM), flash memory, Hard Disk Drives (HDDs), Solid-State Drives (SSDs), optical disk drives, caches, variations or combinations of one or more of the same, or any other suitable storage memory.

[0127] In addition, the term “processor” or “physical processor,” as used herein, generally refers to any type or form of hardware-implemented processing unit capable of interpreting and / or executing computer-readable instructions. In one example, a physical processor may access and / or modify one or more modules stored in the above-described memory device. Examples of physical processors comprise, without limitation, microprocessors, microcontrollers, Central Processing Units (CPUs), Field-Programmable Gate Arrays (FPGAs) that implement softcore processors, Application-Specific Integrated Circuits (ASICs), portions of one or more of the same, variations or combinations of one or more of the same, or any other suitable physical processor.

[0128] Although illustrated as separate elements, the method steps described and / or illustrated herein may represent portions of a single application. In addition, in some embodiments one or more of these steps may represent or correspond to one or more software applications or programs that, when executed by a computing device, may cause the computing device to perform one or more tasks, such as the method step.

[0129] In addition, one or more of the devices described herein may transform data, physical devices, and / or representations of physical devices from one form to another.Additionally or alternatively, one or more of the modules recited herein may transform a processor, volatile memory, non-volatile memory, and / or any other portion of a physical computing device from one form of computing device to another form of computing device by executing on the computing device, storing data on the computing device, and / or otherwise interacting with the computing device.

[0130] The term “computer-readable medium,” as used herein, generally refers to any form of device, carrier, or medium capable of storing or carrying computer-readable- 39 - 14567-738.600 / 135 PCTinstructions. Examples of computer-readable media comprise, without limitation, transmission-type media, such as carrier waves, and non-transitory-type media, such as magnetic-storage media (e.g., hard disk drives, tape drives, and floppy disks), optical -storage media (e.g., Compact Disks (CDs), Digital Video Disks (DVDs), and BLU-RAY disks), electronic-storage media (e.g., solid-state drives and flash media), and other distribution systems.

[0131] A person of ordinary skill in the art will recognize that any process or method disclosed herein can be modified in many ways. The process parameters and sequence of the steps described and / or illustrated herein are given by way of example only and can be varied as desired. For example, while the steps illustrated and / or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed.

[0132] The various exemplary methods described and / or illustrated herein may also omit one or more of the steps described or illustrated herein or comprise additional steps in addition to those disclosed. Further, a step of any method as disclosed herein can be combined with any one or more steps of any other method as disclosed herein.

[0133] The processor as described herein can be configured to perform one or more steps of any method disclosed herein. Alternatively or in combination, the processor can be configured to combine one or more steps of one or more methods as disclosed herein.

[0134] When a feature or element is herein referred to as being "on" another feature or element, it can be directly on the other feature or element or intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being "connected", "attached" or "coupled" to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being "directly connected", "directly attached" or "directly coupled" to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed "adjacent" another feature may have portions that overlap or underlie the adjacent feature.

[0135] Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the - 40 - 14567-738.600 / 135 PCTsingular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as " / ".

[0136] Spatially relative terms, such as "under", "below", "lower", "over", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as "under”, or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "under" can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms "upwardly", "downwardly", "vertical", "horizontal" and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[0137] Although the terms “first” and “second” may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another feature / element. Thus, a first feature / element discussed below could be termed a second feature / element, and similarly, a second feature / element discussed below could be termed a first feature / element without departing from the teachings of the present invention.

[0138] In general, any of the apparatuses and methods described herein should be understood to be inclusive, but all or a sub-set of the components and / or steps may alternatively be exclusive and may be expressed as “consisting of’ or alternatively “consisting essentially of’ the various components, steps, sub-components or sub-steps.

[0139] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word "about" or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and / or position to indicate that-41 - 14567-738.600 / 135 PCTthe value and / or position described is within a reasonable expected range of values and / or positions. For example, a numeric value may have a value that is + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value "10" is disclosed, then "about 10" is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that "less than or equal to" the value, "greater than or equal to the value" and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value "X" is disclosed the "less than or equal to X" as well as "greater than or equal to X" (e.g., where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data represents endpoints and starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “ 15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0140] Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.

[0141] The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have-42 - 14567-738.600 / 135 PCTbeen illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.-43 - 14567-738.600 / 135 PCT

Claims

1. CLAIMSWhat is claimed is:

1. An isolation apparatus, the apparatus comprising:a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from an applicator comprising one or more electrodes in a high voltage (HV) treatment mode and to connect the LV supplemental system to the applicator in a monitoring mode;a second one or more relays configured to connect a high voltage (HV) treatment system to the applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator and the LV supplemental system in the monitoring mode;a relay state detection circuit configured to continuously detect, in real time, a state of the first one or more relays and a state of the second one or more relays in respective HV treatment mode and monitoring mode; and a controller configured to: receive an output from the relay state detection circuit;compare the output from the relay state detection circuit with an expected output to perform failure detection of the first or the second one or more relays; and switch between the HV treatment mode and the monitoring mode.

2. An isolation apparatus, the apparatus comprising:a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from an applicator comprising one or more electrodes in a high voltage (HV) treatment mode and to connect the LV supplemental system to the applicator in a monitoring mode;a second one or more relays configured to connect a high voltage (HV) treatment system to the applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator and the LV supplemental system in the monitoring mode, wherein the second one or more relays is itself electrically isolated such that an activation coil of the second one or more relays is electrically isolated by one or more high voltage, low capacitance isolator(s); and-44 - 14567-738.600 / 135 PCTa controller configured to switch between the HV treatment mode and the monitoring mode to protect the LV supplemental system from an output of the HV treatment system.

3. The apparatus of claims 1 or 2, wherein the controller is configured to communicate with the LV supplemental system and HV treatment system and report the respective HV treatment mode and the monitoring mode, and fault conditions if they occur.

4. The apparatus of any of claims 1-3, further comprising an earth ground switch configured to disconnect one or more protection circuits from an earth ground in the monitoring mode and to connect the one or more protection circuits to the earth ground in the HV treatment mode.

5. The apparatus of any of claims 1-4, further comprising a plurality of ports configured to couple to a plurality of cables for connection to the LV supplemental system, the applicator and / or the HV treatment system.

6. The apparatus of any of claims 1-5, wherein the LV supplemental system comprises at least one of a sensing system, a mapping system, a position tracking / navigation system and / or a pacing system.

7. The apparatus of any of claims 1-6, wherein the HV treatment system comprises a pulse generator and the isolation apparatus is configured to transmit pulses up to 50kV from the pulse generator to the applicator in the HV treatment mode.

8. The apparatus of any of claims 1-7, wherein the apparatus is configured to receive high voltage electric pulses in microsecond and sub-microsecond ranges.

9. The apparatus of any of claims 1-8, wherein the applicator comprises one or more ablation electrodes and a plurality of mapping and / or sensing electrodes.

10. The apparatus of any of claims 1-9, wherein the applicator comprises an electromagnetic (EM) sensor.

11. The apparatus of any of claims 1-10, wherein the one or more electrodes of the applicator are configured to be in electrical communication with both the LV supplemental system in the monitoring mode and with the HV treatment system in the HV treatment mode.-45 - 14567-738.600 / 135 PCT12. The apparatus of any of claims 1 and 3-11 when dependent from claim 1, wherein the relay state detection circuit is isolated from the first and / or second one or more relays by a high-frequency isolator.

13. The apparatus of any of claims 1-12, wherein the second one or more relays is electrically isolated entirely by one or more high frequency / low capacitance isolators.

14. The apparatus of any of claims 1-13, wherein the second one or more relays is a low voltage power relay.

15. The apparatus of claim 2, wherein the one or more high voltage, low capacitance isolator comprises one or more opto-isolators.

16. An isolation apparatus, the apparatus comprising:a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from a first applicator comprising one or more electrodes in a high voltage (HV) treatment mode and to connect the LV supplemental system to the first applicator or a second applicator in a monitoring mode; a second one or more relays configured to connect a high voltage (HV) treatment system to the first applicator in the HV treatment mode and to electrically isolate the HV treatment system from the first and / or second applicator and the LV supplemental system in the monitoring mode;a relay state detection circuit configured to continuously detect, in real time, a state of the first one or more relays and a state of the second one or more relays in respective HV treatment mode and monitoring mode; and a controller configured to: receive an output from the relay state detection circuit;compare the output from the relay state detection circuit with an expected output to perform failure detection of the first or the second one or more relays; and switch between the HV treatment mode and the monitoring mode.

17. An isolation apparatus, the apparatus comprising:a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from an applicator in a high voltage (HV) treatment mode and to connect the LV supplemental system to the applicator in a monitoring mode, the applicator comprising one or more ablation electrodes and a plurality of monitoring / sensing electrodes;-46 - 14567-738.600 / 135 PCTa second one or more relays configured to connect a pulse generator to the applicator in the HV treatment mode and to electrically isolate the pulse generator from the applicator and the LV supplemental system in the monitoring mode;a differential input signal protection circuit configured to limit a voltage between the plurality of monitoring / sensing electrodes of the applicator to less than a differential voltage threshold; anda controller configured to switch between the HV treatment mode and the monitoring mode.

18. The apparatus of claim 17, further comprising an earth ground switch configured to disconnect the LV supplemental system from an earth ground in the monitoring mode and to connect the LV supplemental system to the earth ground in the HV treatment mode.

19. The apparatus of claims 17 or 18, wherein the differential voltage threshold is 24V.

20. The apparatus of any of claims 17-19, wherein the differential input signal protection circuit comprises a plurality of bidirectional protection circuits or circuit components that are coupled from each monitoring / sensing electrode or a sensor input signal line to a hub and a bidirectional protection circuit or circuit component from the hub to earth ground having a higher voltage rating than each bidirectional protection circuit or circuit component of the plurality of bidirectional protection circuits or circuit components.

21. The apparatus of any of claims 17-20, further comprising a plurality of ports configured to couple to a plurality of cables for connection to the LV supplemental system, the applicator and / or the pulse generator.

22. The apparatus of any of claims 17-21, wherein the LV supplemental system comprises at least one of a sensing system, a mapping system, a position tracking / navigation system and / or a pacing system.

23. A method of protecting a low voltage (LV) supplemental system coupled to an applicator during the application of high-voltage energy to the applicator, the method comprising:switching between a high voltage (HV) treatment mode during which a HV treatment system is connected to the first applicator and the LV supplemental system is isolated from the applicator and a monitoring mode during which the-47 - 14567-738.600 / 135 PCTHV treatment system is isolated from the applicator and the LV supplemental system is coupled to the applicator;detecting, in a relay state detection circuit, in real time, a state of a first one or more relays configured to electrically isolate the LV supplemental system from the applicator in the HV treatment mode and to connect the LV supplemental system to the applicator in the monitoring mode, and outputting the state;detecting, in the relay state detection circuit, in real time, a state of a second one or more relays configured to connect the HV treatment system to the applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator in the monitoring mode, and outputting the state; andperforming a failure detection check by comparing the outputs of the relay state detection circuit with an expected output.

24. The method of claim 23, further comprising triggering a safe mode or a shutdown if the failure detection check indicates a mismatch between the outputs of the relay state detection circuit and the expected output.

25. A method of protecting a low voltage (LV) supplemental system coupled to an applicator during an application of high voltage energy to the applicator, the method comprising: switching an isolation apparatus between a high voltage (HV) treatment mode and a monitoring mode, wherein the isolation apparatus is coupled to each of: the LV supplemental system, the applicator and a HV treatment system; electrically isolating the LV supplemental system from the applicator and from the HV treatment system during the HV treatment mode using a first one or more relays configured to electrically isolate the LV supplemental system from the applicator in the HV treatment mode and to connect the LV supplemental system to the applicator in the monitoring mode;electrically isolating the HV treatment system from the applicator and from the LV supplemental system during the monitoring mode using a second one or more relays configured to connect the HV treatment system to the applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator in the monitoring mode; and-48 - 14567-738.600 / 135 PCTelectrically isolating an activation coil of the second one or more relays using one or more high voltage / low-capacitance isolator.

26. A method of protecting a low voltage (LV) supplemental system from high voltage energy delivered to an applicator, wherein the LV supplemental system comprises one or more monitoring / sensing electrodes configured to be in contact with a patient, the method comprising:switching an isolation apparatus between a HV treatment mode and a monitoring mode, wherein the isolation apparatus is coupled to each of: the LV supplemental system, the applicator and a HV treatment system; electrically isolating the LV supplemental system from the applicator and from the HV treatment system during the HV treatment mode using a first one or more relays configured to electrically isolate the LV supplemental system from the applicator in the HV treatment mode and to connect the LV supplemental system to the one or more monitoring / sensing electrodes in the monitoring mode;electrically isolating the HV treatment system from the applicator and from the LV supplemental system during the monitoring mode using a second one or more relays configured to connect the HV treatment system to the applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator in the monitoring mode; andlimiting a voltage between the one or more monitoring / sensing electrodes to less than a differential voltage threshold.

27. The method of claim 26, wherein the HV treatment system comprises a pulse generator.

28. The method of claims 26 or 27, wherein the differential voltage threshold is 24V.

29. The method of any of claims 26-28, wherein the differential voltage is limited by a differential input signal protection circuit comprising a plurality of bidirectional protection circuits or circuit components that are coupled from each of electrode or sensor input signal lines to a hub and a bidirectional protection circuits or circuit components from the hub to earth ground having a higher voltage rating than each bidirectional protection circuits or circuit components of the plurality of bidirectional protection circuits or circuit components.-49 - 14567-738.600 / 135 PCT30. The method of any of claims 26-29, wherein the one or more monitoring / sensing electrodes of the LV supplemental system are configured as wired sensors or electrodes located at or connected to the patient.

31. The method of any of claim 26-29, wherein the one or more monitoring / sensing electrodes are on the applicator.

32. The method of any of claims 26-31 wherein the one or more monitoring / sensing electrodes comprise one or more of: EEG electrodes, pulse oximeter sensors, or blood pressure sensors.

33. The method of any of claims 26-32, wherein the LV supplemental system comprises one of: a pulse oximeters configured to measure SpCh and pulse rate, a surface electrode ECG monitor, a bispectral index (BIS) monitor, or blood pressure sensor.

34. The method of any of claims 26-33, the method comprises delivering, during the high voltage energy delivery, one or more of: pulse field ablation energy, radio frequency (RF) energy, microwave energy, high current and / or high magnetic field energy, or any combinations of such treatment modalities.

35. An isolation apparatus, the apparatus comprising:a first one or more relays configured to electrically isolate a low voltage (LV) supplemental system from one or more monitoring / sensing electrodes of the LV supplemental system in a high voltage (HV) treatment mode and to connect the LV supplemental system to the one or more monitoring / sensing electrodes in a monitoring mode;a second one or more relays configured to connect a high voltage (HV) treatment system to an applicator in the HV treatment mode and to electrically isolate the HV treatment system from the applicator in the monitoring mode;a controller configured to switch between the HV treatment mode and the monitoring mode; andan earth ground switch configured to disconnect signal line protection devices from an earth ground in the monitoring mode and to connect the signal line protection devices to the earth ground in the HV treatment mode.

36. The isolation apparatus of claim 35, wherein the HV treatment system comprises a pulse generator and the HV treatment mode comprises ablation.-50 - 14567-738.600 / 135 PCT37. The isolation apparatus of claims 35 or 36, further comprising a relay state detection circuit configured to continuously detect, in real time, a state of the first one or more relays and a state of the second one or more relays in respective HV treatment mode and monitoring mode, wherein the controller is further configured to: receive an output from the relay state detection circuit, and to compare the output from the relay state detection circuit with an expected output to perform failure detection of the first or the second one or more relays.

38. The apparatus of any of claims35-37, wherein the apparatus is configured to receive electric pulses in microsecond and sub-microsecond ranges.

39. The apparatus of any of claims 35-38, wherein the apparatus is a part of a system comprising the pulse generator and the applicator and wherein the applicator comprises one or more ablation electrodes and a plurality of monitoring and / or sensing electrodes.

40. The apparatus of any of claims 35-39, wherein the applicator comprises an electromagnetic (EM) sensor.

41. The apparatus of any of claims 35-40, wherein the applicator comprises one or more electrodes configured to be in electrical communication with both the LV supplemental system in the monitoring mode and with the pulse generator in the HV treatment mode.

42. The apparatus of any of claims 35-41, wherein the second one or more relays is a low voltage power relay.

43. The apparatus of any of claims 35-42, wherein the second one or more relays is configured to withstand up to 1400 A.-51 - 14567-738.600 / 135 PCT

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