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JP-7856231-B2 - Initiation of IRE generation using a lamp

JP7856231B2JP 7856231 B2JP7856231 B2JP 7856231B2JP-7856231-B2

Inventors

  • アサフ・ゴバリ
  • アンドレス・クラウディオ・アルトマン

Assignees

  • バイオセンス・ウエブスター・（イスラエル）・リミテッド

Dates

Publication Date
20260511
Application Date
20220309
Priority Date
20220216

Claims (9)

  1. A device for ablating tissue within a subject, A probe comprising an electrode configured to be inserted into the lumen of the subject, wherein the electrode is in close proximity to the tissue to be ablated, It is a processor, An immobilization signal configured to immobilize the subject is injected into the subject via the electrodes. A processor is configured to inject an ablation signal into the subject via the electrodes while the subject is immobilized, wherein the ablation signal is configured to ablate the subject's tissue by irreversible electroporation. The ablation signal comprises at least one column of first pulses, and each of the first pulses in the at least one column has a first pulse absolute amplitude. The immobilization signal comprises a plurality of rows of second pulses, each of which has a second pulse absolute amplitude smaller than the first pulse absolute amplitude and is not configured to ablate the tissue . A device in which the absolute amplitude of the second pulse increases monotonically over time.
  2. The apparatus according to claim 1 , wherein the monotonically increasing function is linear.
  3. The apparatus according to claim 1 , wherein the monotonically increasing portion is non-linear.
  4. The apparatus according to claim 1, wherein at least one row of the first pulses includes a plurality of pulses.
  5. The apparatus according to claim 1, wherein the absolute amplitude of the second pulse is 20% to 70% of the absolute amplitude of the first pulse.
  6. The apparatus according to claim 1, wherein the first pulse and the second pulse include bipolar pulses.
  7. The apparatus according to claim 1, wherein the overall duration of the fixed signal is within the range of 0.4 seconds to 0.6 seconds.
  8. The apparatus according to claim 1, wherein the probe comprises a further electrode configured to receive the injected ablation signal and the injected immobilization signal.
  9. The apparatus according to claim 1, further comprising external electrodes located on the skin of the subject, configured to receive the injected ablation signal and the injected immobilization signal.

Description

(Cross-reference of related applications) This application claims the benefit of U.S. Provisional Patent Application No. 63/159,412, filed March 10, 2021, which is incorporated herein by reference. (Field of invention) This disclosure generally relates to ablation used in surgical procedures, and more specifically to ablation performed using irreversible electroporation (IRE). IRE (Irradiation Resonance) is a soft tissue ablation technique that applies short pulses of a strong electric field to create permanent, and therefore lethal, nanopores within the cell membrane, thereby disrupting cellular homeostasis (internal physical and chemical conditions). Cell death after IRE is due to apoptosis (programmed cell death) and not necrosis (cell damage resulting from the action of the cell's own enzymes), as in all other heat or radiation-based ablation techniques. IRE is typically used in tumor ablation in areas where precision and preservation of the extracellular matrix, blood flow, and nerves are critical. Several examples of systems using IRE are provided below. U.S. Patent No. 9,867,652 to Sano et al. describes an IRE applied through the vascular system of an organ to decellularize the organ for the treatment of tumors deeply embedded within the tissue or organ, or to generate a scaffold from existing animal tissue with an existing complete vascular system. The patent states that "by gradually increasing the voltage and test cells within a given tissue, the point at which irreversible electroporation occurs can be determined." U.S. Patent Application No. 2018/0289417(A1) to Schweitzer et al. describes an electroporation system and a method for pre-conditioning tissue for electroporation therapy. The electroporation generator includes an electroporation circuit and a pre-conditioning circuit. The pre-conditioning circuit is configured to be coupled to a pre-conditioning electrode to stimulate the patient's skeletal muscle tissue and is further configured to transmit a pre-conditioning signal to the pre-conditioning electrode. U.S. Patent No. 10,286,108 to Davalos describes how IRE can be used to prepare tissue scaffolds. The scaffolds are derived from natural tissue and prepared using non-thermal, irreversible electroporation. A more complete understanding of this disclosure can be obtained by reading the following detailed description of the embodiments in conjunction with the drawings. This is a schematic diagram of an IRE (irreversible electroporation) system used in ablation procedures.This is a schematic voltage-time graph of a bipolar IRE pulse.This is a schematic voltage-time graph of a bipolar pulse burst.This is a schematic graph of the fixed signal and the IRE ablation signal.This is a flowchart illustrating the steps of the IRE ablation procedure, showing the use of a fixed signal. Overview A fundamental problem with IRE ablation is that the subject may jump or convulse when the IRE pulse is first applied to them. Convulsions are caused by the high electric field of the high-voltage IRE pulse, resulting in muscular, skeletal, or diaphragmatic contractions of the subject. Convulsions can lead to traumatic situations, for example, if the catheter probe is initially positioned at the desired location within the myocardium. First, instead of applying the IRE pulses at their full voltage amplitude, embodiments of this disclosure incorporate a ramp period into pulse generation. During the ramp period, the pulse amplitude is gradually increased while remaining below the effective IRE voltage. During the ramp period, the pulse amplitude is sufficiently low that no IRE occurs. After the ramp period, the full IRE voltage amplitude may be applied, resulting in IRE occurring. The initial low-voltage pulse immobilizes the subject's muscles without causing IRE (irradiation respiration), and therefore the subject remains immobilized and does not spasm when the full IRE voltage is achieved. The ramp can take any convenient shape, such as linear or exponential. The typical length of the ramp period is approximately 0.5 seconds. System Description Referring here to Figure 1, Figure 1 is a schematic diagram of a multichannel IRE system 20 used in an IRE (irreversible electroporation) ablation procedure. In the depicted embodiment, physician 22 performs a multichannel IRE ablation procedure using the IRE system 20. Physician 22 performs the procedure on the heart 52 of subject 24 using an ablation catheter probe 26 having a distal end 28, the distal end 28 comprising a plurality of ablation electrodes 30 arranged along the length of the distal end. The IRE system 20 includes a processor 32 and an IRE module 34, the IRE module including an IRE generator 36 and an IRE controller 38. An IRE generator similar to the generator 36 is described in U.S. Patent Application No. 16/701,989. As detailed below, the IRE generator 36 generates a series of electrical pulses directed to a selected electrode 30 to generate a current 72