Generator for a pulsed field ablation system

Abstract

A generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a system controller; a pulse generator for generating high voltage pulses from an input power supply under control of said system controller; and an output controller for receiving said generated high voltages pulses and outputting a predetermined sequence of therapeutic pulses to said multi-electrode implant.

Description

GENERATOR FOR A PULSED FIELD ABLATION SYSTEMTECHNICAL FIELD

[0001] The present invention relates to the field of Pulsed Field Ablation (PF A) in the treatment of atrial fibrillation; in particular, a generator for generating the pulses for application to an intra-cardiac catheter in a PFA system.BACKGROUND

[0002] Atrial fibrillation (AF) is a widespread heart rhythm disorder that can lead to blood clots and strokes. Catheter ablation has shown promise as a treatment for AF, but conventional methods using heat or cold can cause serious complications.

[0003] Pulsed Field Ablation (PFA) is an innovative technology that offers a safer and more effective alternative. Unlike traditional therapies, PFA uses non-thermal electric fields to precisely ablate heart tissue in a matter of seconds. This tissue-selective approach leads to faster and more durable clinical outcomes for patients. The therapy is performed using an implanted multi-electrode catheter.

[0004] Given the high level of voltage employed (in excess of 1000V) safety to patients and clinicians is paramount. Therefore, it is desirable to provide a system that an operator can be confident it is safe to use.

[0005] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.SUMMARY

[0006] PROBLEMS TO BE SOLVED

[0007] It is an aim and objective of the present invention to provide an improved PFA generator that is capable of operating safely with respect to operators and users.

[0008] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0009] MEANS FOR SOLVING THE PROBLEM

[0010] A generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a system controller; a pulse generator for generating high voltage pulses from an input power supply under control of said system controller; an output controller for receiving said generated high voltages pulses and outputting a predetermined sequence of therapeutic pulses to said multi-electrode implant; an actuator for manual actuation by an operator; wherein, upon determining the manual actuation of said actuator, the generator system outputs the predetermined sequence of therapeutic pulses until the sequence has completed, upon which the generator system reverts to an idle mode, or said actuator is determined to not being manually actuated, upon which the system controller disables the output of therapeutic pulses.

[0011] Preferably, the actuator must be armed by the system controller before it is capable of being manually actuated. The system controller may conduct system analysis upon initiation of the generator system, wherein the arming of the actuator is conditional upon the system analysis finding no faults in the generator system. The system controller may disarm the actuator upon disabling the output of therapeutic pulses.

[0012] Preferably, the system controller disables the output of therapeutic pulses upon determining the occurrence of one or more predetermined events, including: overvoltage detection, undervoltage detection, manual actuation of an emergency stop.

[0013] Preferably, the actuator is a foot pedal.

[0014] Preferably, the generator system further includes a graphical user interface for presenting operational data to the operator and allowing an operator to set and adjust system operating parameters, wherein, during operation of the generator system, the system controller periodically performs a handshake with the graphical user interface and, in the event that a handshake fails the system controller disables the output of therapeutic pulses.

[0015] Preferably, the pulse generator includes an inverter receiving a de electrical input, a transformer for transforming the output of said inverter into a high voltage output and a high voltage storage for storing the high voltage output, wherein said high voltage pulses are generated from said high voltage storage. The high voltage storage may be a capacitor storage bank. Ideally, upon the system controller disabling the output of therapeutic pulses, the system controller disables the inverter to prevent further high voltage from being stored. The system controller may further cause the high voltage storage to be safely discharged.

[0016] According to a further aspect of the present invention there is provided a generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a system controller; a pulse generator for generating high voltage pulses from an input power supply under control of said system controller; an output controller for receiving said generated high voltages pulses and outputting a predetermined sequence of therapeutic pulses to said multi-electrode implant; wherein said system controller monitors Electrocardiograph signals of a patient to determine a heartbeat rhythm, in response to which, said systemcontroller controls said pulse generator and / or output controller to adjust output therapeutic pulses to avoid coinciding with a determined heartbeat.

[0017] According to a further aspect of the present invention there is provided a generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a system controller; a pulse generator for generating high voltage pulses from an input power supply under control of said system controller; an output controller for receiving said generated high voltages pulses and outputting a predetermined sequence of therapeutic pulses to said multi-electrode implant; wherein said system controller is able to reconfigure the generator system in order to provide alternative therapeutic output from said multielectrode implant.

[0018] According to a further aspect of the present invention there is provided a generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a system controller; a pulse generator for generating high voltage pulses from an input power supply under control of said system controller; an output controller for receiving said generated high voltages pulses and outputting a predetermined sequence of therapeutic pulses to said multi-electrode implant; wherein, upon said implant being connected to the generator system, said system controller attempts to recognise said implant and, upon recognising said implant, configures the generator system operating parameter settings in accordance with stored settings associated with said implant.

[0019] Preferably, the implant further comprises a navigation sensor positioned at a distal end of the implant.

[0020] Preferably, the system controller is configured to enable generation of the high voltage only immediately prior to delivery of a therapeutic pulse.

[0021] Preferably, high voltage is discharged during idle states.

[0022] Preferably, the generator system further comprises a configuration memory for storing a profile for the implant, wherein the profile is at least one selected from the group of: physical characteristics of the implant, and implant configurations; wherein the system controller is configured to read the configuration memory upon implant connection.

[0023] Preferably, the output controller is configured to enable or disable selected electrode pairs in response to user input via graphical user interface (GUI).

[0024] Preferably, the therapeutic pulse sequence is configured to be executed across multiple cardiac cycles, synchronised to a patient’s electrocardiogram (ECG) signal, wherein the therapeutic pulse sequence is delivered outside the QRS period.

[0025] Preferably, each electrode pair is configurable to comprise of any two electrodes of the multi-electrode implant.

[0026] Preferably, the system is further configurable for use with electrode geometries that are applied to a patient externally.

[0027] Preferably, the electrode geometries are at least one selected from the group of: clamps, and pads.

[0028] Preferably, the integration of a navigation sensor into the catheter near the contacts. This sensor allows for precise three-dimentional spatial positioning of the tip.

[0029] Preferably, the high voltage can be enabled only when required, just prior to delivery of the energy pulse. This reduces the risk of noise on the mapping system as no voltage generation is taking place.

[0030] Preferably, there is no storage of high voltage when idle so as to reduce the risk to the patient in the event of the failure of the electronics.

[0031] Preferably, the generator has a profile stored for each of the different catheter types. This may include the physical characteristics. These may include the V-Loop, Linear, Big Eye, Clamps, and pads etc.

[0032] Preferably, the firing sequence allows the user to enable or disable electrode pairs when a short circuit is suspected and so reducing the risk of blood clots, arcing etc. The enabling and disabling is done using the GUI and clearly indicating the state on the catheter graphic.

[0033] Preferably, the sequence for the delivery of the PFA therapy can be executed over a series of heartbeats, ensureing the PFA does not interfere with the normal heart rhythm (QRS), when synchronisation is enabled and the generator is connected to a patient monitor (ECG), which provides the synchronisation pulse to the generator. The sequence is timing validated to ensure that with the selected catheter, QRS delay and the therapy burst durations, does not result in a portion of the application during the QRS period and so reducing the risk for adverse events.

[0034] Preferably, the electrode pairs can be made to comprise of any two electrodes, allowing electrode pair optimisation to the physical shape and characteristics of the catheter.

[0035] Preferably, the generator can be configured to allow the use of non-catheter based electrode geometries, for example clamps and pads. These are used for external application, which reduces the risk for complications as a result of the therapy. The pairs and configuration are changeable via the GUI.BRIEF DESCRIPTION OF THE FIGURES

[0036] Figure 1 shows a generator system in accordance with a preferred embodiment;

[0037] Figure 2 shows illustrates the synchronisation of therapeutic pulses;

[0038] Figure 3 shows the operational difference between an uninterrupted therapeutic sequence and a disabled sequence.

[0039] Figure 4 shows the integration of a navigation sensor into a linear array catheter / implant located near the contacts in accordance with a preferred embodiment. This navigation sensor allows for precise three-dimensional spatial positioning of the tip.

[0040] Figure 5 shows the integration of a navigation sensor into a looped catheter / implant located near the contacts in accordance with another preferred embodiment. This navigation sensor allows for precise three-dimensional spatial positioning of the loop with embedded electrodes.DESCRIPTION OF THE INVENTION

[0041] Hardware:

[0042] The PFA generator electronics is designed to deliver a series of electrical pulses to a Catheter that is connected. The control of the electronics is controlled by a microcontroller and Graphic user interface (GUI). The electronics is designed to monitor the operation and provide feedback to the controller and GUI. The generator can be configured to allow different configurations of Catheters to be connected to it.

[0043] With the unit being connected to a patient special attention is made for ensuring the electrical safety and leakage currents to the patient. These are implemented with reference to the relevant sections of the standard IEC 60601-1

[0044] The hardware comprises a series of printed circuit boards (PCB) that perform specific functions.

[0045] All the electronics are mounted in a single enclosure. The front panel in the user interface where all connections are made. These include the connection to the Electrophysiology (EP) recording system, Catheter, foot pedal, Emergency Stop.

[0046] Safe operation is an integral part of the Generator, with a signal needing to be present to allow normal operation, ensuring, any failure, either electrical and / or mechanical, allows the unit to fall back to a safe state.

[0047] Main Components:

[0048] System shown in Fig. 1 consists of the following:1 - PFA Controller PCB2 - Feedback PCB3 - Estop FBPSU PCB4 - Inverter PCB5 - HV Storage PCB6 - Main Transformer7 - Bridge CT PCB8 - Output Pulse Transformer9 - Matrix PCB10 - ECG Sync PCB11 - System Monitoring12 - Catheter interface PCB13 - EP / CIM Interface PCB14 - Fibre optic interconnects15 - Power supplies16 - Foot pedal17 Catheter connected interface (plug and play)

[0049] PCB Description:

[0050] PFA Controller PCB (system controller):

[0051] The controller PCB consists of a CPU, Monitoring Logic, Fibre optic interfaces, analogue 0-5V control outputs, general IO and PSU.

[0052] At power the incoming power will be converted to the required power rails for use by the CPU and PCBs that are plugged into it.

[0053] The input voltage is checked via hardware comparators and provides a valid signal to the fault latches.

[0054] The fault latches monitor the Over current, gate drive, Under Voltage, FB Enable, Reset and bridge drive. Any fault on these signals is latched and must be cleared by the CPU. This signal will prevent the Bridge from firing ensuring safety.

[0055] All the power supply rails are check with a comparator to be above a minimum voltage. This is referenced against a Voltage reference. The outputs are joined to form a common Under Voltage Detection signal.

[0056] The Bridge drive signals are derived from the CPU and interface to Fibreoptic drivers to connect to the Bridge drive circuit. This provides Voltage Isolation and electrical noise immunity. An optical feedback link from the Bridge is provided for monitoring the Bridge.

[0057] The controller has an Isolated USB interface to connect to the GUI. This is a highspeed serial interface. The USB interface, GUI Side, is powered from the GUI Computer.

[0058] The interface to the ECG Sync input is Isolated, both power and signals.

[0059] The Interface to the Foot Pedal is Isolated, both power and signals, Present and Pressed.

[0060] Estop FBPSU PCB:

[0061] The PCB is the interface to the E-Stop button that is fitted to the front panel of the Generator.

[0062] This powers a relay that will be turned on from the main controller, powering the Matric, Inverter and Bridge Driver circuits.

[0063] The main 12V control voltage is fed into this PCB. The power and control from the main controller are connected to this board. The e-stop signal is fed back via this connection.

[0064] The 12v additionally provides an isolated 12v Supply for the feedback board with a fibre optic interface. Serial and status from the feedback board.

[0065] To enable the power the controller will send a pulse to the board and the relay will latch and hold, being powered via the E-stop. Pushing the E-stop will remove power from the Relay and the supply to the switched circuits will be removed the status returned to the CPU.

[0066] Feedback PCB:

[0067] The PCB is powered from an isolated power supply as the circuit is connected to the High Voltage (HV) storage capacitor bank. The communication interface is via fibreoptic. There is a specialist microcontroller on this PCB providing the conversions, interface and control.

[0068] The Input voltage is connected via a high impedance input and scaled to provide a proportional signal that is converted in the local microcontroller. The main CPU can request the voltage at any time.

[0069] The input circuit makes provision for trimming and calibration allowing the return of precision readings.

[0070] Additionally, the Feedback controller can also control the inverter via a fibre optic interface to provide an autonomous HV generation system.

[0071] There is a proprietary communications interface to the module, allowing control and feedback.

[0072] Inverter PCB:

[0073] The PCB is powered from the switched power that is controlled by the CPU.

[0074] The Inverter consists of a control board with a dedicated microcontroller to provide the drive signals for the H-bridge driver for the step-up main transformer.

[0075] When the power is applied the H drive is disabled.

[0076] The power for the H drive comes in to a buffer capacitor. This voltage on the programable PSU is set by the main CPU and is set to a point that if the unit was continuously active then the maximum rating of the capacitor bank will not be exceeded preventing damage. Additionally, this is calculated to ensure that the output pulse voltage will not be exceeded.

[0077] The inverter is designed to drive two types of storage capacitors , a high capacity HV storage capacitor with integrated discharger or a low capacity HV storage capacitor without discharger. The high-capacity high voltage storage capacitor with integrated discharger is advantageously designed to store significant amounts of energy, which is suitable for systems requiring sustained or repeated high-energy discharges. The integrated discharger enables controlled and safe dissipation of stored energy. For the low capacity high voltage storage capacitor, it is advantageously optimised for transient energy storage in applications requiring quick charge / discharge cycles and lower stored energy. As there is no integrated discharger, the system relies on precise control of charge timing. The inverter is able to operate in a demand-driven mode, and activates only when high voltage is needed.

[0078] The inverter has an enable signal that is controlled by the CPU, using the Feedback PCB to enable disable the running of the inverter. Disabling the inverter during idle periods avoids the generation of high switching currents, and so improving system signal integrity and reducing electromagnetic interference in mapping or catheter mapping or measurement systems. More specifically, the inverter is controlled via an enable signal managed by the CPU, interfacing with a Feedback PCB. This PCB monitors inverter states and allows the CPU to dynamically enable or disable the inverter operation based on system conditions or timing requirements. When configured with the low-capacity storage capacitor, the system activates high voltage generation only when required, for example a pulsed operation which his a high-voltage event. The capacitor is quickly charged to the required voltage and remains energised for only a limited predetermined time, thus minimising risk and interference to the operator. The use of a dedicated Feedback PCB allows modular interfacing between the inverter and the CPU, which enables precise diagnostic, status monitoring and fault-handling capabilities.

[0079] When the low capacity storage is used, the high voltage generation is enabled only when required. By doing so, the high voltage on the capacitor is present when required and improves safety for service personnel which confers operational advantages. By energising the high voltage capacitor only when needed, the risk of accidental electricshock during servicing or maintenance is substantially reduced and this is especially important in this system where access to internal components may be possible while the unit is powered. By not charging continuously, there are no high switching currents thus no introduction of noise into the mapping system. Continuous high voltage generation typically involves high-frequency switching, which can inject noise into sensitive systems, for example signal processing, and sensor mapping.

[0080] The microcontroller provides the timing and control of the firing of the H bridge. When the enable is active the drive signal will have a soft start. There is a Shutdown control.

[0081] HV Storage PCB:

[0082] The HV storage PCB consists of three sections, viz. Rectifier, Storage, Safety Discharge

[0083] The output from the Main transformer connects to the rectifiers that convert the signal from the transformer to a number of de voltages that are put in series and fed to the capacitor storage bank.

[0084] This storage is designed to deliver large energy pulses on demand. The currents and voltages present make it hazardous, and extreme caution must be exercised when monitoring and testing.

[0085] The PCB is fitted with a safety discharger that must interfaced via fibre optic to the main controller. This needs to have active signals to turn off the discharger. This is powered by the energy storage and will ensure that storage is in a safe mode in storage. When the discharger is active a red LED is on.

[0086] Main Transformer:

[0087] The main transformer is custom designed to step the adjustable input voltage from the H bridge to 3 identical outputs that go to the HV storage. This is an iron core El type transformer that allows for the changing to the desired HV voltage.

[0088] Bridge CT PCB:

[0089] The bridge drive is connected to the HV storage. The circuit is configured as an H bridge. This consists of SiC High power High Speed Mosfets to deliver the energy to the output pulse transformer.

[0090] Each drive for the FETs is driven by a fibre optic hybrid module that provides the control and interfacing to the CPU which controls the FETs.

[0091] Each hybrid provides the correct bias conditions for the FET that it controls.

[0092] The input to the H Bridge is designed to connect directly to the storage board minimising the inductance in the connections.

[0093] The output goes directly to the output pulse transformer, one lead of which goes through a monitoring CT to allow for detection of excess currents. These will cause the CPU to terminate the delivery of further pulses.

[0094] All Pulses are measured both positive and negative.

[0095] Matrix PCB:

[0096] The output pulse from the Pusle transformer feeds into the Matrix board. The board has 2 functions. Viz. To disconnect the EP monitoring and to configure / route which electrodes are connected to the output at the catheter. The EP monitoring is done using insulated reed relays. The CPU interfaces to the Matrix controller PCB. The relays are selected using a decoder with the default of all off.

[0097] The switching in the matrix can be via relays or via solid state. This allows the routing of the treatment to any pairs of electrodes.

[0098] In this condition, the EP and all electrodes are disconnected and the Catheter is floating. This floating state ensures that no electrical connection exists between the electrodes on the catheter and the EP recording or stimulation system, which provides for safety, signal integrity during configuration, or protection during reconfiguration phases. The decoder ensures that if a channel is selected the EP will be disconnected. This plays a critical gating role as it ensures that if a signal channel is selected for active mapping or recording, the EP system will automatically disconnect from that electrode configuration before switching occurs. This prevents short circuits, minimises cross-talk between electrode pairs, and maintains safe operation during real-time electrode reconfiguration. The pair mapping is fixed for the interface and the IP and IN pair are connected. The pair mapping may refer to how individual electrodes on the catheter are logically grouped for differential signal acquisition or stimulation. In a preferred embodiment, there may be provided a fixed mapping configuration where the electrode pairings are predefined and fixed, such as connecting electrode 1 positive (IP) with electrode 1 negative (IN) to form a single bipolar pair. In another preferred embodiment, the system conduct custom mapping as it can also form custom electrode pairs, for example, IP and 3N where electrodes 1 and 3 are selected to form a measurement or stimulation path. This is especially useful and advantageous in high-density mapping where flexibility is required to explore various inter-electrode distances and orientations for better spatial resolution or signal characterisation. In another preferred embodiment, sequential mapping may be preferred. This may be a sequence of such electrode pair combinations, either in a predefined order or dynamically configured through software. Each custom or fixed pair is activated one at a time, and the system advances to the next pair in the sequence until all relevant electrode combinations have been tested or recorded. Alternatively, the catheter electrodes can be mapped to form custom pairs e.g. IP - 3N etc. This is then set to the next pair in the sequence until the end is reached. The catheter needs to be connected, in which decoding, pairing, and signal acquisition is only enabled when the catheter is phycially and electrically connected to the interface system. This may includeverification through impedance checks, connector presence sensing and / or signal integrity tests. Without a confirmed connection, for increasing the safety, the system can remain in a disabled or safe mode.

[0099] The controller provides a signal that indicates which channel pair is currently connected.

[0100] Important to note that the switching and setup of the matrix must be complete and only done when there is no current flowing.

[0101] Catheter Interface PCB:

[0102] The output pairs from the Matrix go directly to the catheter interface. This has the required 2mm Pin connector sockets and allows the catheter to be configured as required, to create pairs for the pulses to be delivered, e.g. 1~3, 4~9, etc

[0103] The indicator output from the Matrix control goes to LEDs that are visible to the user indicating which pair is being used.

[0104] The different catheters are fitted with a configuration memory that contains the details of the number of electrodes (eg. electrode spacing, electrode configuration such as unipolar / bipolar arrays, numbering and logical assignment such as IP, 2N etc), maximum operating voltages (eg. including thresholds for DC bias voltage limits, peak RF voltage amplitudes, maximum transient voltage conditions), Operating times On and Off durations (duty cycle parameters specifying maximum continuous ‘on- time’, which is the duration for which RF energy or a waveform can be applied without overheating or damaging the catheter as well as the minimum ‘off-time’ or required cooldown period - this is critical for thermal management and to prevent overheating of electrodes or surrounding tissue) and the types of wave form that can be applied (RF radiofrequency ablation, DC direct current pacing, biphasic or monophasic waveforms, pulsed field ablation, diagnostic sensing-only modes). This embedded configuration memory module is integrated into the catheter connector or handle and is electronicallyaccessible by the host system, for example, an EP console, generator, or mapping system upon connection. This configuration memory can advantageously store citrical devicespecific metadata that defines safe and optimal operational parameters, which ensures compatibility, traceability, and safety.

[0105] The system will use this information to enable only the allowed electrode pairs, and the limits of the treatment to be applied.

[0106] If the catheter has the precision guidance / navigation sensor fitted, then the guidance system will connect through this interface. Spatial precision is critical as it supports accurate navigation and localisation within the body, for example but not limited to inside the heart or any other organ, the catheters are fitted with precision guidance sensors. These sensors are integrated into the catheter structure and interface with external guidance systems through a dedicated electrical and / or data interface. This allows third party systems to provide precision spacial position of the catheter. Figures 4 and 5 illustrate the integration of the sensor 40, 50 in different catheters in the active volume / spatial region. Sensor placement is designed to minimise error and maximise coverage within this 3D field, accounting for electromagnetic field uniformity, anatomical access constraints, flexibility and mechanical safety. These sensor(s) are embedded within or near the distal tip or along the shaft of the catheter to allow real-time spatial positioning within a predefined 3D active volume, which may be the working area monitored by the navigation system. It interfaces with the external guidance / navigation system through the main catheter interface connector. This interface may comprise power and ground lines, high-speed digital or analog data lines, and synchronisation signals to align catheter data with the external spatial model. The EP console or navigation system can detect the presence of a precision guidance sensor via the configuration memory or via an auto-detection protocol, which then establishes the required communication protocol with the third-party tracking system.

[0107] EP / CIM Interface PCB:

[0108] The catheter is connected to this output from the Matrix Controller when the generator is in normal patient monitoring mode. When the therapy is being delivered, this connection is broken and becomes open circuit before the output pulse from the Matrix are delivered to the Patient.

[0109] System Monitoring PCB:

[0110] This is used to monitor the current that is flowing to the catheter. It is a CT and is used to monitor the Current shape and the magnitude. Also used for calibration and validation of the pulses delivered.

[0111] ECG Sync PCB

[0112] The ECG Sync interface allows the input from a patient monitor to provide a synchronisation for the delivery of the therapy.

[0113] The circuit take the input current and provides a visual Pulse (RC) on a LED that is visible to the user indicating that a sync is present and correctly detected. The output is a narrow current limited pulse in sync with the input. There is an additional voltage sync output.

[0114] The ECG Sync allows the controller to validate the Therapy can be applied safely between heart beats. This is used to control when Pulses can be applied.

[0115] This circuit is powered from a dedicated isolated power supply provided by the CPU interface.

[0116] The interface on the CPU is fully isolated as it is connected to the patient monitor.

[0117] Power Supplies:

[0118] The Generator is powered by medical grade Power modules that take the input AC and produce a 12Vdc and a controlled Variable output.

[0119] The 12Vdc powers all the control electronics with additional isolation provided with suitable DC-to-DC convertors.

[0120] The Variable PSU is used as the source for to generating the storage voltage. The value for the current limit and Voltage output is set from the CPU and is changed dependant on the desired therapy.

[0121] Foot Pedal (manual actuator):

[0122] The foot pedal interface provides 2 circuits. The one is a present or plugged in detection and the second is the pressed detection. This is active for the duration of the foot pedal being pressed and is used to deliver the therapy.

[0123] This input is connected to the CPU via an Isolated interface.

[0124] Fibre optics:

[0125] The system uses fibre optic connections to provide electrical isolation to the high voltage areas of the generator. With these care needs to be taken to ensure that the ends are polished and inserted fully to ensure correct operation.

[0126] System Wiring:

[0127] The wiring in the generator is designed to handle the voltages ELV and High Voltage safely.

[0128] All the connectors and plugs are locking types and the wires in the system need to be secured to ensure that in the event of a failure no risk is posed to the user or patient. The Case is connected to the protective earth.

[0129] Main Microcontroller software Description:

[0130] Initialization of the PFA Generator (PFA-GEN)

[0131] When the Main Microcontroller is power-on or reset, it will initialize the start-up sequence as follows:Reset all peripherals of the Main Microcontroller,Configure the System Clock, GPIO, timers, I2C, UARTS, Independent WatchDog,Create threads and initialize the RTOS (a multi-tasking system),Configure the PFA-GEN software to an idle state,Start the RTOS kernel.

[0132] Emergency Sequence

[0133] The Emergency Sequence will put the PFA-GEN into a safe idle state. They are:Terminate any pulse train delivery immediately,Disable the inverter to stop charging the capacitor bank,Disarm the PFA-GEN if it is armed,Enable the active load to discharge the capacitor bank.Indicate the state of the PFA-GEN in the GET STATUS return.

[0134] Command handling task

[0135] The Command handling task is responsible for taking serial commands from the GUI and execute the GET or SET commands. All commands will be replied with an ACK or NACK to indicate if the command action is successful or not.

[0136] The GUI is master and the Main Microcontroller is slave in this communication link.

[0137] Each command has its own handler. Some commands are control related, e.g. Power-On, Engaging the Inverter (i.e. start charging), Arming the system to prepare electro pulses for delivery. Some commands are status related, e.g. Over-Current, UnderVoltage, system status.

[0138] The GUI interface allows the various pairs to be enabled / disabled while displaying the firing pattern. This allows for pairs to be controlled and if a short is suspected then disabled, reducing the risk of arcing and blood clots. The GUI allows the operator to view the graphical representation of all available electrode pairs, select individual or multiple pairs for activation, temporarily disable specific pairs from participating in the procedure. This advantageously proides real-time control over the energy delivery or signal mapping process. The firing pattern visualisation may be a real-time representation of which electrode pairs are currently energised or stimulated, the sequence and timing of energy delivery, and intensity or power levels applied to each pair. If a short circuit condition is suspected between electrodes, which may be due to blood bridging, tissue contact, or hardware fault, the system may display abnormal electrical parameters (eg. low impedance or abnormally high return current), it will trigger a warning or alert on the GUI. The operator can manually disable the affected electrode pairs through the GUI to prevent continued energy delivery across the shorted path, and minimise the risk of electrical arcing which could lead to tissue overheating or charring, uncontrolled energy dispersion and formation of blood clots due to local thermal damage.

[0139] When the SET ARM ON command is received, the Main Microcontroller has to check if all alarms are cleared and the system is safe to be armed before acknowledging the ARM command. The system has to be armed before delivery, when the Foot Pedal is depressed, the delivery will commence.

[0140] When the system is ARMED, the Command handling task will block other SET commands (except other priority commands) to avoid any unwanted settings changes during the delivery.

[0141] SET ARM OFF command will revert the system to a standby status even the delivery is in progress.

[0142] WatchDog & Handshaking

[0143] For safety reasons, the Main Microcontroller must be supervised by the GUI at all times. To ensure the Main Microcontroller has a good connection with the GUI, a handshaking signal must be received from the GUI at least once per second. On expiration of 1 second period without the handshaking signal, the system will be reset to the power-on state and capacitor bank is discharged. By the same token, if the GUI doesn’t receive the acknowledgement of the GET STATUS command, it will prompt the user to check the connection between the GUI & the PFA Generator.

[0144] Sensing and handling of Over Current Protection(OCP)

[0145] The Bridge CT PCB and the PFA Controller PCB modules provide the Over Current Protection which set a hardware latch to activate a GPIO input to the Main Microcontroller. This high priority signal will be treated immediately which execute the Emergency Sequence and signal the Over Current flag in the system status. An error message of OCP detected will be logged.

[0146] Sensing and handling of Under Voltage Protection(UVP)

[0147] The PFA Controller PCB module provides the Under Voltage Protection which set a hardware latchs to activate a GPIO input to the Main Microcontroller. This high priority signal will be treated immediately which execute the Emergency Sequence and signal the Under Voltage flag in the system status. An error message of UVP detected will be logged.

[0148] Voltage control and self-discharging active load

[0149] The Voltage Control Task is responsible for charging the capacitor bank to the set value and controlling the active load according to different states of the system.

[0150] The set value of the system is converted to a PWM value output to the Power Supply module.

[0151] It reads the capacitor voltage through the Feedback Board.

[0152] The control loop will keep the capacitor voltage within a certain range. It will enable the Active Load if it finds the capacitor voltage is too high.

[0153] When the system is ARMED, and the Foot Pedal is depressed, the Voltage Control Task will 1) disable the active load, 2) ensure the inverter is enabled, 3) keep charging the capacitor bank and 4) maintain the capacitor voltage in the ready-for- ablation range until the delivery sequence is completed or terminated.

[0154] Synchronization and firing control

[0155] When the system is ARMED, and the Foot Pedal is depressed, the PFA Controller Task will prepare to deliver the pulses to the catheter.

[0156] It will check if the capacitor voltage is within the ready-for-ablation range. If the capacitor voltage cannot reach the ready-for-ablation range in configured number of seconds, the firing actions will be cancelled and alarmed to the GUI as an error.

[0157] The system is ready to fire.

[0158] If a delay from the QRS wave is required, the PFA-Controller Task will wait for the next QRS trigger signal and wait for the QRS -Delay (milli-seconds) to expire before carrying on the firing activities.

[0159] If the delivery action is interrupted by any high priority events such as Over Current, Under Voltage, lifting of the Foot Pedal, Emergency Stop button depressed etc, the firing actions will be terminated immediately.

[0160] After the QRS-Delay, the PFA Controller Task will switch on the active channel sequentially via the relay matrix. If the channel is successfully turned on, the Pulse generation timers of CPU are triggered and fire. The timing of the output pulse trains is properly programmed and aligned such that the H-bridge is turned on in the way to switch the capacitor bank DC voltage to a bipolar pulse train. The bipolar pulse trains are multiplied by a step-up transformer to a high voltage bipolar pulse train before it is routed to the catheter electrodes through the relay matrix.

[0161] After one round of delivery (or one burst), the PFA Controller Task will wait for a pre-defined period before the next delivery until all bursts are delivered.

[0162] When all bursts are delivered, the relay matrix will be switched to its default, which is direct all catheter electrodes to the EP interface.

[0163] QRS Sync & Auto- Adjust Therapy Algorithm

[0164] The PFA Generator is intended to deliver therapy ie pulse trains in between the T wave and P wave of heartbeats. Sometime when the patient has a higher heart rate, the window between the T and P wave is too short for a full pulse train. The PFA Generator can work out the optimal therapy and split it into multiple parts to deliver to multiple heartbeats.1. Collect the defined R-T wave delay (in milliseconds) from EP operator or the doctor2. Configure the PFA Generator QRS Delay setting.3. Measure the time (X) between 2 consecutive QRS Sync pulse.4. Using X to work out the T-P wave window duration (Tw) from general equation.5. Using the current settings : pulse width (Tp), number of pulses (N), number of pair of electrodes (M) to work out the total duration of a pulse train (Ttotal)-6. If Ttotal is less than or equal to Tw, then deliver the whole pulse train to all electrode pairs at once7. Else Ttotai is greater than Tw, then split the pulse train to multiple parts and deliver separately to multiple heartbeats.

[0165] Sensing and handling of Foot Pedal

[0166] The Foot Pedal status is monitored by the Main Microcontroller. When the system is armed and ready to deliver, the depressed Foot Pedal will initiate the delivery of pulse train. If the Foot Pedal is released during the delivery process, this will terminate the delivery immediately.

[0167] The presence of Foot Pedal is monitored by the Main Microcontroller. This high priority signal will be treated immediately which execute the Emergency Sequence and signal a Missing Foot Pedal error.

[0168] Sensing and handling of Emergency Stop

[0169] The Emergency Stop button will execute the Emergency Sequence and put the generator to a power-on reset state. The Generator remains in a safe condition until the Emergency Stop button is reset.

[0170] Sensing and handling of other major faults

[0171] The Feedback Board Fault, Gate Driver Fault and Bridge Fault are high priority events and the handler will execute the Emergency Sequence and put the generator to a power-on reset state. The Generator remains in a safe condition until these events are cleared.

[0172] Catheter selected Auto-configuration Algorithm

[0173] Each catheter has a specific settings to optimize the therapeutic deliverable. For example the electrode pairs, maximum pulse voltage, pulse width, etc. The PFA Generator has a build-in function to detect the catheter and configure the generator settings.1. The PFA Controller CPU will continuously to check if a catheter is connected to the system.2. identify the catheter type by electrical connection or communicate with the build-in memory of the catheter.3. When the catheter type is determined, a corresponding set of configuration is retrieved from a stored repository4. PFA Controller CPU will configure the Pulse Voltage, Pulse Width, Pulse count, Electrode firing pattern corresponding to the identified catheter type.5. The GUI will indicate the catheter is detected and the PFA Generator is successfully configured.6. When no catheter or unknown catheter is detected, the GUI will indicate the catheter is not detected and the PFA Generator is not ready to deliver therapy.

[0174] A preferred embodiment of a therapy may involve the following parameters as detailed in the table below.

[0175] The Contact Impedance Measurement (CIM) method enables stimulation of electrodes in any arbitrary configuration, with both phase and frequency - ranging from approximately 100 kHz to 600 kHz, which is controlled by a frequency synthesizer under the management of a microcontroller and a graphical user interface (GUI).Electrode selection for stimulation is dynamically managed by the microcontroller and directly influences the overall system performance.

[0176] When switching between different electrode configurations or updating signal parameters, the system employs a controlled fade-in and fade-out mechanism. This transition technique minimises electrical noise and prevents interference with the electrophysiology (EP) system.

[0177] Stimulating and sensing electrodes using a fixed configuration, with signals applied at varying phases, further contributes to noise reduction. This approach ensures that the addition of CIM functionality remains electrically transparent to the EP system.

[0178] Electrode-specific signal parameters are optimised based on the physical geometry of the electrodes and the catheter or device or implant in which they are embedded. Supported geometries include, but are not limited to, V-loop (10 electrodes), linear arrays (6 electrodes), and big-eye configurations (4 electrodes). Configuration profiles for these geometries are pre-stored within the CIM system and automatically applied upon selection via the GUI.

[0179] Additionally, the CIM system supports contact detection for externally applied electrodes such as those used in clamps, surface patches, or other non- catheter / non-implant applications. Electrode channels not required for a specific measurement can be selectively enabled or disabled, allowing the contact detection routine to operate with a focused set of electrodes, thereby improving accuracy and minimising signal artifacts.

[0180] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms, in keeping with the broad principles and the spirit of the invention described herein.

[0181] The present invention and the described preferred embodiments specifically include at least one feature that is industrial applicable.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a. a system controller; b. a pulse generator for generating high voltage pulses from an input power supply under control of said system controller; c. an output controller for receiving said generated high voltage pulses and outputting a predetermined sequence of therapeutic pulses to said multielectrode implant; d. an actuator for manual actuation by an operator; wherein, upon determining the manual actuation of said actuator, the generator system outputs the predetermined sequence of therapeutic pulses until the sequence has completed, upon which the generator system reverts to an idle mode, or said actuator is determined to not being manually actuated, upon which the system controller disables the output of therapeutic pulses.

2. The generator system of claim 1 , wherein the actuator must be armed by the system controller before it is capable of being manually actuated.

3. The generator system of claim 2, wherein the system controller conducts a system analysis upon initiation of the generator system, wherein the arming of the actuator is conditional upon the system analysis finding no faults in the generator system.

4. The generator system of claim 2 or 3, wherein the system controller disarms the actuator upon disabling the output of therapeutic pulses.

5. The generator system of any one of the preceding claims, wherein said system controller disables the output of therapeutic pulses upon determining the occurrence of one or more predetermined events.

6. The generator system of claim 5, wherein said one or more predetermined events include: overvoltage detection, undervoltage detection, manual actuation of an emergency stop.

7. The generator system of any one of the preceding claims, wherein said actuator is a foot pedal.

8. The generator system of any one of the preceding claims, further including a graphical user interface for presenting operational data to the operator and allowing an operator to set and adjust system operating parameters, wherein, during operation of the generator system, the system controller periodically performs a handshake with the graphical user interface and, in the event that a handshake fails the system controller disables the output of therapeutic pulses.

9. The generator system of any one of the preceding claims, wherein the pulse generator includes an inverter receiving a de electrical input, a transformer for transforming the output of said inverter into a high voltage output and a high voltage storage for storing the high voltage output, wherein said high voltage pulses are generated from said high voltage storage.

10. The generator system of claim 9, wherein said high voltage storage is a capacitor storage bank.

11. The generator system of claim 9 or 10, wherein upon the system controller disabling the output of therapeutic pulses, the system controller disables the inverter to prevent further high voltage from being stored.

12. The generator system of claim 11, wherein the system controller further causes the high voltage storage to be safely discharged.

13. The generator system of any one of the preceding claims wherein said generated high voltage pulses provided to said output controller are monitored and assessed as to whether they remain within predetermined set parameters.

14. The generator system according to any one of the preceding claims, wherein said receives and monitors realtime operating parameters of a connected multi-electrode implant to assess proper functioning of said implant.

15. A generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a. a system controller; b. a pulse generator for generating high voltage pulses from an input power supply under control of said system controller; c. an output controller for receiving said generated high voltages pulses and outputting a predetermined sequence of therapeutic pulses to said multielectrode implant; wherein said system controller monitors Electrocardiograph signals of a patient to determine a heartbeat rhythm, in response to which, said systemcontroller controls said pulse generator and / or output controller to adjust output therapeutic pulses to avoid coinciding with a determined heartbeat.

16. A generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a. a system controller; b. a pulse generator for generating high voltage pulses from an input power supply under control of said system controller; c. an output controller for receiving said generated high voltages pulses and outputting a predetermined sequence of therapeutic pulses to said multielectrode implant; wherein said system controller is able to reconfigure the generator system in order to provide alternative therapeutic output from said multi-electrode implant.

17. The generator system according to claim 16, wherein said alternative therapeutic output is Intracardiac defibrillation.

18. A generator system for generating output pulses to be applied to a multi-electrode implant of Pulsed Field Ablation system, the generator system including: a. a system controller; b. a pulse generator for generating high voltage pulses from an input power supply under control of said system controller;c. an output controller for receiving said generated high voltages pulses and outputting a predetermined sequence of therapeutic pulses to said multielectrode implant; wherein, upon said implant being connected to the generator system, said system controller attempts to recognise said implant and, upon recognising said implant, configures the generator system operating parameter settings in accordance with stored settings associated with said implant.

19. The generator system according to claim 18, wherein if the system controller cannot recognise said implant, said system controller attemptes to access an embedded memory in said implant in order to determine if said embedded memory has any stored operating parameter settings and configures generator system operating parameter settings in accordance with the determined stored settings from said embedded memory.

20. The generator system according to any one of the preceding claims, wherein the implant further comprises a navigation sensor positioned at a distal end of the implant.

21. The generator system according to claim 20, wherein the system controller is configured to enable generation of the high voltage only immediately prior to delivery of a therapeutic pulse.

22. The generator system of claim 21 , wherein high voltage is discharged during idle states.

23. The generator system of any one of the preceding claims, wherein the generator system further comprises a configuration memory for storing a profile for the implant, whereinthe profile is at least one selected from the group of: physical characteristics of the implant, and implant configurations; wherein the system controller is configured to read the configuration memory upon implant connection.

24. The generator system of any one of the preceding claims, wherein the output controller is configured to enable or disable selected electrode pairs in response to user input via graphical user interface (GUI).

25. The generator system of any one of the preceding claims, wherein the therapeutic pulse sequence is configured to be executed across multiple cardiac cycles, synchronised to a patient’s electrocardiogram (ECG) signal, wherein the therapeutic pulse sequence is delivered outside the QRS period.

26. The generator system of any one of the preceding claims, wherein each electrode pair is configurable to comprise of any two electrodes of the multi-electrode implant.

27. The generator system of any one of the preceding claims, wherein the system is further configurable for use with electrode geometries that are applied to a patient externally.

28. The generator system of claim 27, wherein the electrode geometries are at least one selected from the group of: clamps, and pads.

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