Directionally Focused Ablation With a Permeable Electrode Sheath
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Solution Overview
Problem
Existing tissue ablation techniques, particularly thermal methods like cryoablation and radiofrequency ablation, are time-consuming and risk tissue damage due to high energy use, while non-thermal pulsed field ablation (PFA) can cause collateral damage when not directionally controlled, wasting energy and affecting non-target tissues.
Innovation Solution
A medical device with a permeable sheath surrounding electrodes, using a hydrophilic permeable membrane to insulate non-target areas from pulsed electric fields, allowing focused energy delivery to cardiac tissue through a permeable sheath and insulation material, such as hydrophobic microspheres, to minimize energy dispersion into blood and reduce collateral damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-directional PFA is used, then ablation can be performed without thermal damage, but energy is wasted in non-target tissues and collateral damage occurs
Solution Approach 1:
The electrode surface is divided into directionally selective zones with different properties. The directional contact portion has high conductivity for focused energy delivery, while other portions have reduced conductivity or are insulated, creating local quality variations that direct energy flow preferentially toward the target tissue and away from non-target areas.
Solution Approach 2:
The electrode is segmented into multiple functional regions: a directional contact portion for focused energy delivery and other portions with reduced or blocked energy delivery. This segmentation allows independent control of energy distribution patterns, enabling precise targeting while minimizing energy waste in surrounding non-target tissues.
2Reliability
If thermal ablation techniques are used, then ablation can be performed effectively, but tissue damage risk increases due to high energy requirements
Solution Approach 1:
The invention replaces thermal ablation mechanisms with non-thermal pulsed field ablation. Instead of using continuous high-energy thermal fields that cause collateral tissue damage, the system uses short-duration pulsed electric fields that create transmembrane potential differences to achieve ablation through electropermeabilization, eliminating the harmful thermal effects while maintaining ablation effectiveness.
Solution Approach 2:
The system employs periodic pulsed electric fields rather than continuous energy delivery. Short-duration pulses are delivered in controlled intervals, allowing tissue to return to baseline between pulses and preventing cumulative thermal damage while maintaining effective ablation through repeated electropermeabilization events.
3Productivity
If PFA energy is delivered without directional control, then treatment can be performed quickly, but collateral damage to non-target tissue occurs
Solution Approach 1:
The electrode structure incorporates local quality variations with a directional contact portion designed for energy delivery and other portions with reduced conductivity or insulation. This allows the system to maintain quick pulsed energy delivery while spatially constraining the electric field to target areas, preventing collateral damage to adjacent non-target tissues.
Solution Approach 2:
Insulating materials are introduced as intermediaries between the electrode and non-target tissues. These materials selectively block electric field lines from reaching sensitive structures while allowing field penetration toward the target, serving as a mediator that directs energy flow without requiring complex electrode redesign.
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 device enables precise, non-thermal ablation with reduced collateral damage and energy waste by directing pulsed electric fields specifically to treatment sites, minimizing tissue disruption and enhancing lesion creation while reducing heating effects.
Implementation Method 1
a permeable sheath at least partially surrounding the at least one electrode, the permeable sheath being permeable to a pulsed electric field and impermeable to an insulation material
Implementation Method 2
the permeable sheath is composed of a hydrophilic permeable membrane and the insulation material is at least one of a gas and a hydrophobic material such that the insulation material is retained within the hydrophilic permeable membrane
Implementation Method 3
PFA involves the application of short pulsed electric fields (PEF) which may reversibly or irreversibly destabilize cell membranes through electropermeabilization without generally affecting the structural integrity of the tissue components
Data Source
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AI summary
A medical device for directionally focusing energy to a treatment site, the medical device including a shaft having an elongated body defining a proximal portion and a distal portion opposite the proximal portion, the distal portion including at least one electrode having a contact portion and a permeable sheath at least partially surrounding the at least one electrode, the permeable sheath being impermeable to an insulation material emitted from a fluid source configured to be coupled to the shaft.