Pulsed Field Ablation Waveform Pulse Periods
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Solution Overview
Problem
Current tissue ablation systems using pulsed field ablation face challenges in achieving optimal lesion depth and minimizing thermal heating and muscle contractions during electroporation therapy.
Innovation Solution
The system employs a catheter with multiple electrodes and a pulse generator that produces a waveform with a first and second pulse pattern, where the pulse period between the start of the first and second pulse patterns ranges from 1 millisecond to 100 milliseconds, enhancing lesion depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional pulsed field ablation waveforms are used with short pulse periods, then the treatment time is reduced, but the lesion depth is insufficient
Solution Approach 1:
The patent applies periodic action by using a pulse train waveform consisting of multiple individual pulses delivered at specific intervals. The pulse train includes a first pulse pattern followed by a second pulse pattern, where the pulse period between corresponding pulses ranges from 1-100 milliseconds. This periodic structure allows cumulative electroporation effects to build up lesion depth over time while maintaining controlled treatment duration through the finite number of pulses in each pattern.
2Duration of action of moving object
If higher energy pulses are delivered to increase lesion depth, then thermal heating of tissue increases, but this may cause unwanted thermal damage
Solution Approach 1:
The periodic pulse delivery allows thermal energy to dissipate between pulses, preventing cumulative thermal damage while still achieving sufficient lesion depth through repeated electroporation cycles. The 1-100 millisecond pulse period is specifically chosen to be long enough for thermal relaxation but short enough to maintain overall treatment efficiency.
Solution Approach 2:
The patent replaces thermal-based ablation mechanisms with electroporation-based cell membrane disruption. By using high-voltage electrical pulses to create pores in cell membranes rather than relying on thermal heating, the system achieves tissue ablation through a non-thermal mechanism, thereby avoiding unwanted thermal damage while still creating effective lesions.
3Reliability
If high voltage pulses are applied to achieve effective ablation, then muscle contractions are induced, but this complicates the procedure
Solution Approach 1:
The patent applies local quality by using bipolar electrode configuration where positive and negative pulses are delivered through adjacent electrodes positioned close together. This creates a highly localized electric field concentrated at the tissue interface between the electrodes, achieving effective ablation only at the target site while minimizing the spatial spread of electrical stimulation that would otherwise trigger distant muscle contractions.
Solution Approach 2:
The alternating positive and negative pulses in the pulse train create a bipolar waveform that delivers energy in balanced phases. This periodic alternation between polarities reduces net charge accumulation and minimizes the likelihood of triggering sustained muscle contractions compared to unipolar delivery, while still achieving effective electroporation at the tissue interface where the electric field is most concentrated.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively increases lesion depth while reducing thermal effects and muscle contractions, thereby improving the efficacy of electroporation therapy.
Implementation Method 1
Electroporation is a substantially non-thermal ablation technique that involves applying strong electric-fields that induce pore formation in the cellular membrane. The electric field may be induced by applying a relatively short duration pulse which may last, for instance, from a nanosecond to several milliseconds
Implementation Method 2
PFA generally involves delivering high voltage pulses from electrodes disposed on a catheter. For example, voltage pulses may range from less than about 50 volts to about 10,000 volts or higher. When such an electric field is applied to tissue in an in vivo setting, the cells in the tissue are subjected to an increased trans-membrane potential, which opens the pores on the cell plasma membrane
Data Source
AI summary
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 delivered using at least one of the plurality of electrodes. The waveform includes a first pulse pattern, and a second pulse pattern that is consecutive to the first pulse pattern, wherein a pulse period defined between a start of the first pulse pattern and a start of the second pulse pattern is in a range from 1 millisecond (ms) to 100 ms, such that the waveform facilitates increasing lesion depth.