IRE Pulse Generation With Ramp-Up Immobilization
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Solution Overview
Problem
Applying IRE pulses initially causes muscle spasms in subjects due to high electrical fields, leading to potential trauma and procedural complications.
Innovation Solution
Incorporating a ramp period into the pulse generation, where amplitudes are gradually increased to a safe level before applying full IRE voltage, ensuring muscle immobilization without causing irreversible electroporation during the ramp.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full IRE voltage is applied immediately, then ablation effectiveness is improved, but muscle spasms and traumatic situations occur
Solution Approach 1:
The patent applies a preliminary immobilizing signal before the full IRE ablation signal. This preliminary action locks the subject's muscles in advance, preventing spasms when the high-voltage ablation pulses are subsequently applied. The ramp period gradually increases voltage to achieve immobilization without causing irreversible electroporation, preparing the subject for safe ablation.
Solution Approach 2:
The patent uses an immobilizing signal that opposes the harmful muscle contraction effect of the subsequent IRE pulses. By applying this counteracting signal first, the system prevents the harmful spasms that would otherwise occur when full ablation voltage is applied, allowing effective ablation without trauma.
2Reliability
If ramp period is incorporated to prevent spasms, then subject safety is improved, but procedure time is increased
Solution Approach 1:
The patent changes the voltage parameter over time during the ramp period, gradually increasing from zero to the full IRE voltage. This time-varying parameter approach prevents muscle spasms by keeping initial voltages below the threshold for irreversible electroporation, while still achieving the necessary voltage for effective ablation within an acceptable time frame.
Data Source
AI summary
A method for ablating tissue in a subject, including providing a probe, having an electrode, that is inserted into a lumen of the subject, so that the electrode is in proximity to the tissue to be ablated. An immobilizing signal is injected into the subject, via the electrode, that immobilizes the subject. When the subject is immobilized, an ablation signal is injected via the electrode into the subject, the ablation signal being configured to ablate the tissue of the subject by irreversible electroporation. The ablation signal has at least one train of first pulses, each of the first pulses in the at least one train having a first pulse absolute amplitude, and the immobilizing signal has one or more trains of second pulses, each of the second pulses in the one or more trains having a second pulse absolute amplitude less than the first pulse absolute amplitude.