Cycled pulsing to mitigate thermal damage for multi-electrode irreversible electroporation therapy
Inventors
O'Brien, Timothy J. • Neal, II, Robert E. • Davalos, Rafael V.
Assignees
Virginia Tech Intellectual Properties Inc • Angiodynamics Inc • Virginia Polytechnic Institute and State University
Publication Number
US-11950835-B2
Publication Date
2024-04-09
Expiration Date
2040-06-29
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Abstract
Methods and systems for distributing electrical energy to tissue which minimize Joule heating, thermal effects, and/or thermal damage, without sacrificing efficacy of treatment, are described. The methods and systems are particularly suitable to electrical energy-based therapies employing multiple electrodes, such as arrays of electrodes.
Core Innovation
The invention provides methods and systems for distributing electrical energy to tissue in a manner that minimizes Joule heating, thermal effects, and thermal damage without sacrificing treatment efficacy. These methods are particularly suitable for electrical energy-based therapies employing multiple electrodes, such as arrays of electrodes for irreversible electroporation (IRE) and related treatments. The invention strategically subdivides the total number of electrical pulses among multiple electrode pairs and distributes them over several cycles, optionally incorporating delays between pulses or cycles to further reduce thermal effects.
The core problem addressed by the invention is the undesired thermal damage that can result from conventional multi-electrode electroporation therapies. In conventional pulse schemes, all pulses are delivered through one electrode pair before switching to the next, which can lead to excessive heating, tissue coagulation, and potential risk to critical structures. Alternative methods to mitigate thermal effects—such as active cooling—may add complexity or limit the practicality of treatments, especially for large or irregularly shaped tumors.
The invention introduces cycled pulsing protocols, where electrical pulses are cycled between different electrode pairs, with or without active delays, and with optional optimization of the electrode pair activation order to further reduce consecutive activation of any single electrode. The methods can be performed using a variety of electrode geometries—including surface and needle electrodes—and a wide range of electrical parameters such as voltage, pulse duration, and frequency, thus maintaining flexibility across various clinical scenarios. The corresponding systems include arrays of electrodes and programmable pulse generators capable of implementing these strategies to reduce Joule heating while preserving or enhancing ablation zone size.
Claims Coverage
The patent contains two independent claims which define the scope of the inventive features related to multi-electrode electroporation therapies that utilize cycled pulsing schemes to mitigate thermal damage.
Cycled pulsing for electrical energy delivery to tissue
A method of treating tissue by delivering a total number of electrical pulses to a target region using a number of electrodes, wherein: - The pulses are delivered by activating various pairs of the electrodes across a number of cycles. - The activating is performed a number of times that equals the total number of electrical pulses, divided by the number of pairs of electrodes, divided by the number of cycles. - Within at least one cycle, specific first and second electrode pairs and third and fourth electrode pairs are activated in sequence, each pair comprising different electrodes. - Electrical energy is thereby strategically distributed to sub-regions within the target region to treat tissue while mitigating one or more of thermal effects, thermal damage, potential for Joule heating, or delivery of electric current to the target region. - At least one of the electrodes is a surface electrode and at least one is a needle electrode.
Distribution of electrical pulses by electrode pairs over cycles
A method of treating tissue with electrical energy while mitigating thermal damage by: - Distributing a total number of electrical pulses to the tissue via a plurality of electrode pairs over multiple cycles. - Each electrode pair is activated to receive one or more pulse train during each cycle. - Within at least one cycle, first and second electrode pairs are activated in sequence, and third and fourth electrode pairs are activated in sequence, with each pair consisting of different electrodes. - At least one of the electrodes in one or more pairs is a surface electrode and at least one is a needle electrode.
The independent claims focus on methods for strategically distributing electrical pulses among multiple electrode pairs over cycles and specific activation patterns, with the intent of reducing thermal damage, and systems capable of implementing these protocols using combinations of surface and needle electrodes.
Stated Advantages
Minimizes Joule heating and thermal damage to tissue during electrical energy-based therapies.
Allows effective tissue ablation while preserving the efficacy of treatment zone size.
Enables clinicians to position electrodes closer to critical structures without significant risk of thermal injury.
Permits more comprehensive treatment of tumors near sensitive anatomical features by reducing local heat accumulation.
Reduces overall treatment time compared to some conventional methods.
Facilitates a treatment approach that may promote favorable immune responses due to non-thermal cell ablation.
Documented Applications
Treatment of malignant and benign tumors in various tissues, including cancer and non-cancerous growths, by electrical energy-based therapies such as irreversible electroporation (IRE) and high frequency irreversible electroporation (HFIRE).
Non-thermal ablation of diverse cancer types listed explicitly, including but not limited to liver, pancreatic, bladder, brain, kidney, prostate, and soft tissue cancers.
Ablation of benign or non-cancerous tumors or growths such as uterine fibroids, adenomas (polyps), lipomas, cysts, and other abnormal or undesired growths.
Treatment of cardiac arrhythmias such as arterial fibrillation.
Fat removal procedures using electrical energy-based ablation.
Applicable to electrical energy-based therapies including reversible electroporation, electrochemotherapy, electrogenetherapy, supraporation, and combinations thereof.
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