Flexible Ablation Electrode Irrigant Distribution
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Solution Overview
Problem
Current ablation electrode assemblies face challenges with temperature correlation between the electrode and tissue interface during RF ablation, leading to impedance rise, coagulum formation, and excessive tissue damage, while also struggling to efficiently deliver energy due to rigid electrode designs.
Innovation Solution
The ablation electrode assembly incorporates a flexible electrode shell with an irrigant distribution element and a thermal insulator, featuring irrigation passageways and a conductive polymer coating, which allows for flexible conformation to cardiac anatomy and efficient fluid distribution to prevent coagulum formation and enhance energy delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a rigid electrode design is used, then structural stability is improved, but adaptability to cardiac anatomy deteriorates
Solution Approach 1:
The electrode assembly is divided into multiple segments including a hub, electrode shaft, and electrode head that can move independently. The electrode head can rotate and deflect relative to the shaft, allowing adaptation to cardiac anatomy while the hub remains stable for catheter attachment.
Solution Approach 2:
The electrode design incorporates dynamic elements including rotation capability around the longitudinal axis and deflection capability perpendicular to the shaft. These dynamic features allow the electrode to conform to the three-dimensional cardiac anatomy while maintaining structural integrity through controlled movement.
2Use of energy by moving object
If RF ablation energy is increased to improve treatment effectiveness, then energy delivery is improved, but tissue damage worsens due to excessive heat
Solution Approach 1:
An irrigation fluid is introduced as an intermediary between the electrode and cardiac tissue. The fluid flows through channels in the electrode head and creates a cooling barrier that allows high RF energy delivery while preventing excessive heat accumulation and tissue damage through thermal regulation.
Solution Approach 2:
The irrigation fluid undergoes phase transition from liquid to vapor at the electrode-tissue interface, absorbing excessive heat through evaporation. This phase change mechanism effectively dissipates thermal energy and prevents tissue charring and steam pop while allowing effective ablation.
3Reliability
If irrigation fluid flow is increased to prevent coagulum formation, then coagulum prevention is improved, but fluid consumption worsens
Solution Approach 1:
Irrigation fluid is delivered locally through channels positioned at the electrode head and distributed through pores in the electrode surface. This localized delivery concentrates the cooling effect precisely where heat generation occurs, preventing coagulum formation with minimal overall fluid consumption compared to general irrigation.
Solution Approach 2:
The electrode incorporates hydraulic channels for fluid delivery and uses pressure-driven flow through the electrode structure. The fluid flows through internal channels and exits through surface pores, creating efficient localized cooling with controlled fluid consumption through hydraulic principles.
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 design improves temperature correlation, reduces coagulum formation, and enables deeper and more efficient energy delivery during RF ablation by maintaining effective fluid flow and flexible electrode conformation, thereby minimizing tissue damage and improving procedural efficiency.
Implementation Method 1
The electrode core member comprises a thermal insulator having a reduced thermal conductivity
Implementation Method 2
The electrode core member has a distal end; a proximal end; and at least one irrigation passageway. The at least one irrigation passageway extends from the inner cavity to the outer surface of the electrode core member
Implementation Method 3
At least a portion of the circumference and at least a portion of the length of the axially extending passageway can include a coating of an electrically non-conductive material
Data Source
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AI summary
Ablation electrode assemblies 10 having a longitudinal axis 64 include an electrode core member 44; an electrode shell 46; and an irrigant distribution element 100. The electrode core member 44 comprises a thermal insulator and has a first end 48; a second end 50; and at least one irrigation passageway. The electrode shell 46 comprises an electrically conductive material, defines an inner volume, and has a first end 48; and a second end 50. The second end 50 of the electrode shell 46 is configured for connection to the first end 48 of the electrode core member 44. The electrode shell 46 is sufficiently flexible for deflection of the distal end 78 of the electrode shell 46 relative to the longitudinal axis 64 of the ablation electrode assembly 10. The irrigant distribution assembly comprises a first end; and a second end, wherein the second end of the irrigant distribution element 100 defines a circumferential irrigation port 106 between the irrigant distribution element 100 and the electrode core member 44.