Pulsed Field Ablation Electrode Selection for Deeper Lesions
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Solution Overview
Problem
Intravascular or percutaneous medical procedures face challenges with existing pulsed field ablation (PFA) devices due to the complexity of device structure and undesired muscle contractions from monopolar PFA, while bipolar PFA provides weaker ablation effects.
Innovation Solution
A medical system with a data processing device that selects and activates specific groups of electrodes to perform 'pseudo-monopolar' bipolar pulsed field ablation, blending the benefits of both modes by spacing electrodes to achieve deeper tissue lesions with reduced muscle contractions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If monopolar PFA is used to generate deeper electric field penetration, then tissue ablation depth is improved, but muscle contraction and stimulation increase
Solution Approach 1:
The catheter electrode array is segmented into multiple independently controllable electrode groups arranged along the catheter shaft. The system selectively activates specific electrode groups to create localized electric fields for ablation, while maintaining inactive electrodes as references. This segmentation allows the system to achieve deep tissue penetration at specific locations without generating widespread muscle contractions that would occur with monopolar activation of the entire electrode array.
Solution Approach 2:
The system implements local quality by creating localized electric fields through selective activation of specific electrode groups. Each active electrode group generates a confined electric field that penetrates to a controlled depth at its specific location, while adjacent areas remain unaffected. This localized approach enables deep ablation at the treatment site without the diffuse muscle stimulation characteristic of monopolar PFA.
2Object-affected harmful factors
If bipolar PFA is used to reduce muscle contraction, then muscle stimulation is improved, but ablation effect strength decreases
Solution Approach 1:
The system dynamically adjusts the configuration and activation of electrode groups based on real-time procedural requirements. The controller can selectively activate different electrode groups, adjust activation timing, and modify electric field parameters to optimize both ablation strength and muscle contraction reduction. This dynamic control allows the system to adapt the bipolar configuration to achieve strong ablation effects while minimizing muscle stimulation.
Solution Approach 2:
The system changes key parameters including the number of active electrode groups, the spacing between active and reference electrodes, the pulse duration, and the voltage magnitude. By adjusting these parameters, the system can optimize the electric field distribution to achieve strong ablation effects through bipolar configuration while controlling muscle contraction. For example, increasing the spacing between active and reference electrodes can enhance ablation depth while reducing muscle stimulation.
3Ease of operation
If intravascular catheter systems are used for PFA, then access to target tissue is improved, but device structure complexity increases
Solution Approach 1:
The catheter electrode array is designed with multi-functionality, serving both as a delivery mechanism for the ablation procedure and as the active treatment device. The same catheter structure that provides intravascular access also contains the electrode groups that generate the electric fields for ablation. This universal design eliminates the need for separate access devices and treatment electrodes, reducing overall system complexity while maintaining ease of access to target tissue.
Solution Approach 2:
The electrode groups are nested within the catheter structure, with the catheter shaft providing a protective and flexible housing for the electrode array. The electrode groups are arranged concentrically or in nested configurations within the catheter, allowing compact packaging that maintains the flexibility needed for intravascular delivery while providing the necessary electric field generation capability. This nesting approach reduces the overall device footprint and simplifies the catheter structure.
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
The system enables efficient and controlled bipolar pulsed field ablation with deeper tissue penetration and reduced muscle stimulation, improving the efficacy of PFA procedures.
Implementation Method 1
PFA is an ablation method that employs high voltage pulse delivery in proximity to target tissue. The electric field applied by the high voltage pulses in PFA physiologically changes the tissue cells to which the energy is applied (e.g., puncturing or perforating the cell membrane to form various pores therein). If relatively greater field strength is established, then permanent, and sometimes larger, pores form in the tissue cells, the pores allowing loss of control of ion concentration gradients (both inward and outward) thereby resulting in cell death (e.g., in a process sometimes referred to as irreversible electroporation).
Implementation Method 2
If a relatively low field strength is established, the formed pores may close in time and cause the cells to maintain viability (e.g., a process sometimes referred to as reversible electroporation).
Data Source
AI summary
A medical system may be configured at least to receive a user-selection of a first group of electrodes in a spatial distribution of electrodes; cause, at least in response to the user-selection of the first group of electrodes, a machine-selection of a second group of electrodes in the spatial distribution of electrodes, each electrode in the machine-selected second group of electrodes spaced, according to the spatial distribution, from an electrode in the user-selected first group of electrodes at least by a respective interposed electrode set in the spatial distribution of electrodes; and cause bipolar pulsed field tissue ablation between the user-selected first group of electrodes and the machine-selected second group of electrodes, while omitting at least any electrode of each respective interposed electrode set from causing bipolar pulsed field tissue ablation.