System and method of unipolar PFA
Systems and methods for unipolar Pulse-Field Ablation (PFA) are disclosed for reducing spasm and/or other adverse nerves stimulation effects during delivery of PFA pulses. The system includes or is connected to one or more motion sensors to be placed at one or more regions of a patient's body for monitoring spasm thereat. The system includes a signal switch capable of selectively connecting a PFA energy generator to selected one or more of return electrode patches for delivery of PFA pulses and/or pacing signals through the selected electrode patches; and a processor that monitors motion sensed by the motion sensor(s) during delivery of the PFA pulses or pacing signals to identify nerve stimulation effects, such as spasm, to facilitate, based on the monitoring, selection of certain electrode patches by which the PFA pulses may be delivered without, or with reduced spasm or other adverse effects of excessive nerves stimulation.
1 . A method for unipolar Pulse-Field Ablation (PFA), comprising:
providing a PFA system with a catheter having an electrode at its tip as a first pole, and at least two electrode patches on the patient's skin as return electrodes serving as second poles;
placing at least one motion sensor near the patient's body configured to identify spasm related motion patterns;
performing frequency analysis on output from the at least one motion sensor, wherein the analysis includes comparing amplitudes of frequency components of said output within a defined frequency range to a threshold;
based on the comparing, selecting at least one of the return electrodes for further pulse delivery.
2 . The method of claim 1 , wherein said at least one motion sensor comprises a position sensor and wherein said output is indicative of position changes of tissue near said at least one motion sensor respectively.
3 . The method of claim 1 , wherein at least one motion sensor comprises inertial measurement unit (IMU) and wherein said output is indicative of changes in velocity or acceleration of tissue near said at least one motion sensor respectively based on inertial measurements performed by said IMU.
4 . The method of claim 3 , wherein said inertial measurement unit (IMU) comprises at least one accelerometer.
5 . The method of claim 1 , wherein said at least one motion sensor is a wireless motion sensor comprising a wireless communication utility capable of wirelessly communicating said signals output to the PFA system.
6 . The method of claim 1 , wherein said spasm related motion patterns is associated with changes in at least one of a position, velocity and acceleration of the tissue near said at least one motion sensor.
7 . The method of claim 6 wherein said processing comprises at least one of spectral analysis and filtering to identify said frequency components being within said frequency range.
8 . The method of claim 1 wherein selecting the at least one return electrode based on the comparing, comprises carrying out the following upon identification of said spasm related motion pattern:
issuing an indication about the identified spasm related motion pattern; and
responsive to said indication, obtaining user instructions for selection of the at least one return electrode;
thereby delivering said one or more PFA pulses or pacing signals via the at least one of the return electrodes in accordance with said user instructions.
9 . The method of claim 1 , wherein said selecting the at least one of the return electrodes is performed automatically based on performing the frequency analysis.
10 . The method of claim 1 , further comprising positioning the at least one motion sensor in at least one of the following:
at, or near, at least one respective electrode patch of said plurality of electrode patches;
at, or near, at least one region of interest of the subject's body at which spasm related motion pattern may occur due to nerve stimulation affected by said delivery of the PFA pulses or pacing signals.
11 . The method of claim 1 , wherein said selecting of the at least one of the return electrodes may include selection of more than one electrode patch to serve as said second pole.
12 . The method of claim 11 wherein in case said more than one electrode patch are selected, said delivering of the PFA pulses or pacing signals comprises adjusting the relative portions of the said PFA pulses or pacing signals delivered through each of the selected electrode patches based on said monitoring, to thereby avoid or reduce spasm or other adverse effects of nerve stimulation.
13 . The method of claim 1 , wherein at least one of said electrode patches comprises a coupling member suitable for attachment of one of said at least one motion sensor thereto.
14 . A system for unipolar pulse-field ablation (PFA), comprising:
a catheter with a tip electrode as a first pole;
at least two electrode patches configured to attach to a patient's skin and serve as return electrodes (second poles);
at least one motion sensor for placement near the patient's body and configured to identify spasm related motion patterns;
a pulse generator configured to deliver PFA pulses or pacing signals between the catheter electrode and one of the at least two electrode patches;
a processor configured to:
perform frequency analysis on output from the at least one motion sensor, wherein the analysis includes comparing amplitudes of frequency components of said output within a defined frequency range to a threshold;
based on the comparing, select at least one of the return electrodes for further pulse delivery.
15 . The system of claim 14 , wherein said at least one motion sensor comprises at least one of a position sensor and an inertial measurement unit.
16 . The system of claim 14 , wherein said at least one motion sensor is a wireless motion sensor, and the system comprising a wireless communication utility capable of wirelessly communicating with said at least one motion sensor to obtain therefrom the output indicative of motion sensed thereby.
17 . The system of claim 14 , wherein said spasm related motion patterns are associated with changes in at least one of a position, velocity and acceleration of the tissue near said at least one motion sensor.
18 . The system of claim 14 comprising a user interface, and wherein said selecting the at least one return electrode based on the comparing comprises carrying out the following upon identification of said spasm related motion pattern:
operating said user interface to issue an indication about the identified spasm related motion pattern; and
responsive to said indication, obtaining via said user interface, instructions for selection of the return electrodes;
thereby delivering said one or more PFA pulses or pacing signals via the at least one of the return electrodes in accordance with said instructions.
19 . The system of claim 14 adapted for carrying out said automatically based on said monitoring of the spasm related motion patterns sensed by said at least one motion sensor.
20 . The system of claim 14 adapted for connection with at least one motion sensor comprising at least one of the following:
at least one motion sensor arranged at, or near, at least one respective electrode patch of said plurality of electrode patches;
at least one motion sensor arranged at, or near, at least one region of interest of the subject's body at which spasm related motion pattern may occur due to nerve stimulation affected by said delivery of the PFA pulses or pacing signals.
21 . The system of claim 14 wherein said selecting of the at least one of the return electrodes may include selection of more than one electrode patch to serve as said second pole.
22 . The system of claim 21 wherein said signal switch is configured and operable to adjust relative portions of the said PFA pulses or pacing signals being delivered through each of the selected electrode patches; and in case said more than one electrode patch are selected, said processor adjusts said relative portions based on said monitoring, in order to avoid or reduce spasm near the selected electrode patches.
23 . The system of claim 14 adapted to connect to at least one additional sensor capable of sensing additional effects of nerve stimulation due to said delivery of PFA pulses or pacing signals; and wherein said at least one processor is adapted to further monitor the signals obtained from said additional sensor and further select said certain one or more electrode patches based on the further monitoring of the signal from the additional sensor.