Using unipolar configuration for irreversible-electroporation (IRE)
A pulsed field ablation (PFA) system includes a composite electrode, a body-surface electrode, a PFA generator, and a processor. The composite electrode is coupled to a distal end of a catheter configured for insertion into an organ of a patient. The body-surface electrode is configured to be attached to a skin of the patient. The PFA generator is configured to be electrically connected to the composite electrode of the catheter and to the body-surface electrode, and to generate Direct-Current (DC) PFA pulses. The processor is configured to control the PFA generator to apply the DC PFA pulses between the composite electrode and the body-surface electrode while the composite electrode is placed in contact with target tissue of the organ and the body-surface electrode is in contact with the skin of the patient.
1. A pulsed field ablation (PFA) system, comprising:
multiple electrodes coupled to a distal end of a catheter configured for insertion into an organ of a patient;
a body-surface electrode configured to be attached to a skin of the patient;
a PFA generator, which is configured to be electrically connected to the multiple electrodes of the catheter and to the body-surface electrode, and to generate Direct-Current (DC) PFA pulses, wherein the DC PFA pulses are configured for ablating target tissue of the organ; and
a processor, which is configured to control the PFA generator to apply the DC PFA pulses between the multiple electrodes and the body-surface electrode while the multiple electrodes are placed in contact with target tissue of the organ and the body-surface electrode is in contact with the skin of the patient; and
a switching assembly connected between a proximal end of the catheter and the PRA generator, wherein the switching assembly is only configured for connecting all the multiple electrodes to one lead of a PFA generator output prior to ablating the target tissue with the DC PFA pulses, and wherein the connecting all the multiple electrodes to one lead is based on electrically shorting the multiple electrodes.
2. The PFA system according to claim 1 , wherein electrically shorting the multiple electrodes is configured to form a single composite electrode configured for simultaneously ablating an entire circumference of an ostium of a pulmonary vein (PV).
3. The PFA system according to claim 1 , wherein the catheter comprises an expandable frame coupled to the distal end of the catheter, and wherein the multiple electrodes are disposed on the expandable frame.
4. The PFA system according to claim 1 , wherein the PFA generator is configured to generate the DC PFA pulses with voltage polarities that alternate from pulse to pulse.
5. The PFA system according to claim 1 , wherein the PFA generator is configured to generate the DC PFA pulses in multiple bursts separated by pause intervals.
6. The PFA system according to claim 1 , wherein the DC PFA pulses are dual-polarity DC PFA pulses.
7. The PFA system according to claim 1 , wherein the processor is configured to at least one of capture signals and track respective locations of each of the multiple electrodes inside a heart based on the switching assembly disconnecting the imposed electrical short.
8. A pulsed field ablation (PFA) method, comprising:
inserting into an organ of a patient multiple electrodes coupled to a distal end of a catheter;
attaching a body-surface electrode to a skin of the patient;
applying Direct-Current (DC) PFA pulses configured for ablating target tissue of the organ between the multiple electrodes of the catheter and the body-surface electrode while the multiple electrodes are placed in contact with target tissue of the organ and the body-surface electrode is in contact with the skin of the patient; and
connecting a switching assembly between a proximal end of the catheter and the generator, wherein the switching assembly is only configured for toggling between connecting and disconnecting all the multiple electrodes to one lead of a PEA generator;
operating the switching assembly to electrically short the multiple electrodes prior to applying the DC PFA pulses for delivering a unipolar DC PFA ablation signal for ablating the target tissue.
9. The PFA method according to claim 8 , wherein electrically shorting the multiple electrodes is configured to form a single composite electrode configured for simultaneously ablating an entire circumference of an ostium of a pulmonary vein (PV).
10. The PFA method according to claim 8 , wherein applying the DC PFA pulses comprises applying the DC PFA pulses with voltage polarities that alternate from pulse to pulse.
11. The PFA method according to claim 8 , wherein applying the DC PFA pulses comprises applying the DC PFA pulses in multiple bursts separated by pause intervals.
12. The PFA method according to claim 8 , wherein the DC PFA pulses are dual-polarity DC PFA pulses.
13. The PFA method according to claim 8 , comprising at least one of capturing signals and tracking respective locations of each of the multiple electrodes inside a heart based on the switching assembly disconnecting the imposed electrical short.