CN-122028862-A - Systems and methods for reducing microbubbles in electroporation applications

Abstract

An electroporation system is provided. The electroporation system includes a catheter comprising a plurality of electrodes, and a pulse generator coupled to the catheter, the pulse generator configured to generate a waveform to be transmitted using at least one of the plurality of electrodes. The waveform includes a plurality of pulse groups, each pulse group including a plurality of loops, and each loop including a plurality of pulses, wherein each of the plurality of pulses has a pulse width of 3 microseconds (μs) or less, wherein each pulse group includes no more than ten loops, wherein the plurality of pulse groups includes at least ten pulse groups, and wherein the pulse width, the number of loops per pulse group, and the number of pulse groups help reduce microbubble formation.

Inventors

• L. Mittal
• J. J. Daley
• L. B. Moon
• Fisch, J.M.

Assignees

• 圣犹达医疗用品心脏病学部门有限公司

Dates

Publication Date

20260512

Application Date

20241022

Priority Date

20231025

Claims (20)

1. 1. An electroporation system comprising: A catheter comprising a plurality of electrodes, and A pulse generator coupled to the catheter, the pulse generator configured to generate a waveform to be transmitted using at least one of the plurality of electrodes, the waveform comprising: a plurality of pulse groups, each pulse group comprising a plurality of loops, and each loop comprising a plurality of pulses, wherein each of the plurality of pulses has a pulse width of 3 microseconds (μs) or less, wherein each pulse group comprises no more than ten loops, wherein the plurality of pulse groups comprises at least ten pulse groups, and wherein the pulse width, the number of loops per pulse group, and the number of pulse groups help reduce microbubble formation.
2. 2. An electroporation system as claimed in claim 1 wherein the plurality of pulses comprises both positive and negative pulses.
3. 3. An electroporation system as claimed in claim 1, wherein the plurality of pulses comprises: A first pulse transmitted between a first electrode of the plurality of electrodes and a second electrode of the plurality of electrodes, wherein the first electrode is set to a positive voltage for transmitting the first pulse, and A second pulse transmitted between the first electrode and a third electrode of the plurality of electrodes, wherein the first electrode is set to a negative voltage for transmitting the second pulse.
4. 4. An electroporation system according to claim 1 wherein each of the plurality of pulses has a pulse width of 1 μs or less.
5. 5. An electroporation system as claimed in claim 1, wherein the plurality of pulse bursts comprises at least fifteen pulse bursts, and wherein each pulse burst comprises no more than five loops.
6. 6. An electroporation system as claimed in claim 1, wherein the plurality of pulse bursts comprises at least twenty pulse bursts, and wherein each pulse burst comprises no more than three loops.
7. 7. A pulse generator for an electroporation system, the pulse generator configured to be coupled to a catheter comprising a plurality of electrodes and configured to generate a waveform to be transmitted using at least one of the plurality of electrodes, the waveform comprising: a plurality of pulse groups, each pulse group comprising a plurality of loops, and each loop comprising a plurality of pulses, wherein each of the plurality of pulses has a pulse width of 3 microseconds (μs) or less, wherein each pulse group comprises no more than ten loops, wherein the plurality of pulse groups comprises at least ten pulse groups, and wherein the pulse width, the number of loops per pulse group, and the number of pulse groups help reduce microbubble formation.
8. 8. The pulse generator of claim 7, wherein the plurality of pulses comprises both positive and negative pulses.
9. 9. The pulse generator of claim 7, wherein the plurality of pulses comprises: A first pulse transmitted between a first electrode of the plurality of electrodes and a second electrode of the plurality of electrodes, wherein the first electrode is set to a positive voltage for transmitting the first pulse, and A second pulse transmitted between the first electrode and a third electrode of the plurality of electrodes, wherein the first electrode is set to a negative voltage for transmitting the second pulse.
10. 10. An electroporation system comprising: A catheter comprising a plurality of electrodes, and A pulse generator coupled to the catheter, the pulse generator configured to generate a waveform to be transmitted using at least one of the plurality of electrodes, the waveform including at least a first pulse transmitted between a first electrode of the plurality of electrodes and a second electrode of the plurality of electrodes, and A ground electrode arrangement configured to release charge accumulated on the first and second electrodes during transmission of the first pulse from the first and second electrodes.
11. 11. An electroporation system as claimed in claim 10 wherein the ground electrode arrangement comprises a ground electrode positioned adjacent the first and second electrodes.
12. 12. An electroporation system as claimed in claim 10 wherein the ground electrode arrangement comprises a switching circuit configured to periodically switch the first and second electrodes to ground.
13. 13. An electroporation system as claimed in claim 10 wherein the waveform is a biphasic waveform.
14. 14. The electroporation system of claim 10, wherein the waveform is a monophasic waveform.
15. 15. An electroporation system comprising: A catheter comprising a plurality of electrodes, and A pulse generator coupled to the catheter, the pulse generator configured to generate a waveform to be transmitted using at least one of the plurality of electrodes, the waveform comprising: a plurality of consecutive pulses transmitted between a first active electrode of the plurality of electrodes and a second electrode of the plurality of electrodes, wherein each of the plurality of pulses is a negative pulse, wherein the first active electrode has a larger surface area than the second electrode, and wherein the first active electrode is set to a positive polarity.
16. 16. An electroporation system as claimed in claim 15 wherein the first active electrode comprises a single electrode.
17. 17. An electroporation system as claimed in claim 15 wherein the first effective electrode comprises two or more electrodes.
18. 18. The electroporation system of claim 15 wherein the first active electrode and the second electrode comprise splines on a basket catheter.
19. 19. The electroporation system of claim 18 wherein the first active electrode comprises two splines on the basket catheter.
20. 20. An electroporation system as claimed in claim 15 wherein the first active electrode and the second electrode comprise electrodes on a linear catheter.

Description

Systems and methods for reducing microbubbles in electroporation applications Cross Reference to Related Applications The present application claims priority from U.S. provisional patent application No. 63/545,657, filed on 25 at 10/2023, the entire contents of which are incorporated herein by reference. Technical Field The present disclosure relates generally to tissue ablation systems. In particular, the present disclosure relates to applying electroporation therapy using waveforms that help reduce microbubble formation. Background Ablation therapy is well known for treating various conditions affecting human anatomy. For example, ablation therapy may be used to treat atrial arrhythmias. Lesions may form in the tissue when the tissue is ablated, or at least subjected to ablation energy generated by an ablation generator and delivered by an ablation catheter. Electrodes mounted on or within the ablation catheter are used to cause tissue destruction of cardiac tissue to correct symptoms such as ventricular and atrial arrhythmias including, but not limited to, ectopic atrial tachycardia, atrial fibrillation and atrial flutter. Arrhythmia (i.e., arrhythmia) can lead to various dangerous symptoms including asynchrony of atrioventricular contractions and blood flow stagnation, which in turn can lead to various diseases and even death. It is believed that the primary cause of atrial arrhythmias is stray electrical signals within the left or right atrium of the heart. The ablation catheter delivers ablation energy (e.g., radiofrequency energy, cryoablation, laser, chemicals, high-intensity focused ultrasound, etc.) to heart tissue to form lesions in the heart tissue. The damage blocks an undesired electrical path, thereby limiting or preventing stray electrical signals that lead to arrhythmias. Electroporation is a basic non-thermal ablation technique involving the application of a strong electric field to induce pore formation in the cell membrane. The electric field may be induced by applying a pulse of relatively short duration, which may last for example from 1ns to several milliseconds. Such pulses may be repeated to form a pulse train. When such an electric field is applied to tissue in an in vivo environment, cells in the tissue experience an increased transmembrane potential, thereby opening pores in the cytoplasmic membrane. Electroporation may be reversible (i.e., the temporarily open pores will be re-closed) or irreversible (i.e., the pores will remain open). For example, in the field of gene therapy, reversible electroporation (i.e., temporary opening of pores) is used to transfect high molecular weight therapeutic vectors into cells. In other therapeutic applications, a suitably configured pulse train may be used alone to cause cell destruction, such as by causing irreversible electroporation. For example, pulsed Field Ablation (PFA) may be used to perform transient Pulmonary Vein Isolation (PVI). PFA generally involves the transmission of high voltage pulses from electrodes disposed on a catheter. For example, the voltage pulse may range from less than about 500 volts to about 2400 volts or more. These fields may be applied between pairs of electrodes (bipolar therapy) or between one or more electrodes and a return patch (monopolar therapy). In PFA, different waveforms may be used to achieve different goals. For example, certain waveforms may produce larger or smaller lesion sizes than others. In addition, certain waveforms produce higher or lower total energy transfer than others (less total energy transfer generally corresponds to less target tissue heating). As another example, certain waveforms are more likely to induce muscle contraction in a patient. In general, it is desirable to deliver electrical perforation therapy in a relatively short time frame with a relatively small number of therapeutic applications. Furthermore, it is often desirable to avoid thermal heating of the tissue, and to have little to no skeletal muscle recruitment (i.e., to avoid muscle contraction). In addition, it is also generally desirable to reduce the likelihood of waveform generation of persistent atrial arrhythmias. Since PFA for PVI (or other application) involves applying an electrical pulse in the blood pool, PFA for PVI (or other application) may induce microbubble formation in some instances. Microbubble formation can be attributed to, for example, a combination of electrolysis and gas displacement due to shock waves. Microbubbles are generally undesirable. Thus, it is desirable to reduce or eliminate microbubble formation in PFA applications. Disclosure of Invention In one aspect, an electroporation system is provided. The electroporation system includes a catheter comprising a plurality of electrodes, and a pulse generator coupled to the catheter, the pulse generator configured to generate a waveform to be transmitted using at least one of the plurality of electrodes. The waveform includes a plurality of pu