Pulsed Field Ablation Catheter With Impedance Loads for Low-Thermal Lesions
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Solution Overview
Problem
Existing ablation therapies, such as radiofrequency energy, cause significant thermal effects and muscle contractions, and may lead to sustained atrial arrhythmias, necessitating improved methods for precise and efficient tissue ablation.
Innovation Solution
The use of pulsed field ablation (PFA) systems with a catheter and return electrodes, coupled with impedance loads, to deliver high-voltage electric pulses for irreversible electroporation, minimizing thermal heating and muscle recruitment, and controlling lesion formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radiofrequency energy is used for ablation, then tissue destruction is achieved, but significant thermal effects and muscle contractions occur
Solution Approach 1:
The patent changes the fundamental parameter of energy delivery from continuous thermal energy (radiofrequency) to pulsed electrical fields. By using short-duration high-voltage pulses (e.g., 100-1000 volts for 100 microseconds to 10 milliseconds), the system achieves irreversible electroporation that destroys tissue without significant thermal heating or musclecontractions, directly resolving the contradiction between effective tissue destruction and harmful thermal/muscular side effects
Solution Approach 2:
The patent replaces the thermal mechanism (heat-based tissue destruction via radiofrequency) with an electrical field mechanism (irreversible electroporation). This substitution eliminates the need for thermal heating while achieving the same therapeutic goal of tissue destruction, thereby removing the harmful thermal effects and musclecontractions associated with traditional radiofrequency ablation
2Reliability
If high voltage pulses are applied for PFA, then irreversible electroporation is achieved, but thermal heating may still occur
Solution Approach 1:
The patent employs periodic pulsed delivery of electrical fields with specific parameters (voltage amplitude, pulse duration, pulse interval) to achieve irreversible electroporation. The pulsed nature allows tissue to return to baseline temperature between pulses, preventing cumulative thermal heating while maintaining the electroporation effect. Typical protocols use multiple pulses delivered over seconds to minutes with adequate cooling intervals
Solution Approach 2:
The patent optimizes electrical field parameters (pulse duration in the microsecond to millisecond range, voltage amplitude of 100-1000 volts) to maximize electroporation effectiveness while minimizing resistive heating. By carefully controlling these parameters, the system achieves cell membrane permeabilization without exceeding thermal thresholds that would cause unwanted heating
3Reliability
If multiple therapy applications are used to achieve complete ablation, then thorough tissue treatment is achieved, but procedure time increases
Solution Approach 1:
The patent delivers multiple electrical pulses in rapid succession (continuous pulsed action) to achieve complete and uniform ablation in a single application site. This continuous delivery of therapeutic effect eliminates the need for repeated catheter insertions or prolonged treatment sessions, reducing overall procedure time while ensuring thorough tissue treatment through cumulative electroporation damage
4Area of stationary object
If waveform parameters are optimized for larger lesion size, then more tissue is ablated, but overall energy delivery and heating increase
Solution Approach 1:
The patent uses specific waveform parameters (pulse duration of 100 microseconds to 10 milliseconds, voltage amplitude of 100-1000 volts) that create a non-monotonic relationship between energy delivery and lesion size. By operating at these optimized parameters, the system achieves maximal electroporation effect with minimal energy input, creating large lesions without proportional increases in heating or total energy consumption
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
PFA achieves deeper and more precise lesions with reduced thermal effects and muscle contractions, enabling faster pulmonary vein isolation and focal ablation procedures.
Implementation Method 1
PFA generally involves delivering high voltage pulses from electrodes disposed on a catheter. These fields may be applied between pairs of electrodes (bipolar therapy) or between one or more electrodes and a return patch (monopolar therapy). 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.
Implementation Method 2
less overall energy delivery generally corresponds to less heating of the target tissue
Data Source
AI summary
An electroporation system is provided. The electroporation system includes a catheter including at least one therapeutic electrode, a plurality of return electrodes, a pulse generator configured to apply energy between the at least one therapeutic electrode and the plurality of return electrodes to generate a lesion at the at least one therapeutic electrode, and at least one impedance load, each of the at least one impedance load coupled between the pulse generator and one of the plurality of return electrodes.