Capacitive Force Sensor for Electrophysiology Catheters
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Solution Overview
Problem
Current cardiac catheterization technologies lack a reliable method to measure the force applied by electrodes during tissue contact, which is crucial for effective ablation procedures, especially in treating cardiac arrhythmias by creating circumferential lesions around pulmonary veins.
Innovation Solution
Incorporation of a micro capacitive tactile sensor in the distal section of electrophysiology catheters, which measures force by detecting changes in capacitance upon tissue contact, allowing for precise calibration and assessment of the applied force, regardless of electrode configuration as a tip, ring, or balloon electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a force sensor is incorporated into the catheter to measure tissue contact force, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces traditional mechanical force sensors with a capacitive sensing system. The capacitive sensor measures force through changes in capacitance between two plates, eliminating the need for complex mechanical strain gauges or load cells. This substitution of mechanical measurement with electrical field-based measurement reduces device complexity while maintaining measurement precision.
Solution Approach 2:
The capacitive sensor is integrated into the flexible catheter structure using thin-film technology. The sensor plates are embedded within or on the surface of the catheter's flexible materials, allowing the sensor to conform to the catheter's shape and movement without adding rigid structural complexity. This integration approach maintains catheter flexibility while enabling force measurement.
2Measurement precision
If multiple electrodes are integrated on the catheter for comprehensive tissue contact assessment, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The catheter integrates multiple electrodes that serve dual functions: electrical ablation/mapping and capacitive force sensing. The same electrode structures that deliver therapeutic energy also function as capacitive sensors for measuring tissue contact force. This multi-functionality eliminates the need for separate sensing electrodes, reducing overall device complexity while improving comprehensive tissue contact assessment.
Solution Approach 2:
The patent merges the ablation electrode and force sensing electrode into a single integrated structure. The capacitive sensor plates are positioned adjacent to or as part of the ablation electrode assembly, allowing simultaneous measurement of electrical properties and mechanical contact force. This consolidation reduces the number of separate components and simplifies the overall device architecture.
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
Enables accurate measurement and feedback of force applied during tissue contact, enhancing the quality and consistency of ablation lesions by ensuring optimal electrode-tissue interaction, thereby improving the effectiveness of arrhythmia treatment procedures.
Implementation Method 1
a capacitive force sensor having a first plate affixed to the shell, a second plate distal of the first plate and configured for contact with the tissue, and an elastically compressible dielectric between the first and second plates, wherein the force sensor has a first capacitance when the first and second plates are separated by a first distance, and the force sensor has a second capacitance when the first and second plates are separated by a second different from the first distance
Data Source
AI summary
An electrophysiology catheter has a micro capacitive tactile sensor provided in the distal section. The distal section may include a tip electrode, a ring electrode and/or a balloon catheter adapted for tissue contact. The capacitive force sensor is configured to exhibit a change in capacitance with tissue contact wherein the force applied with tissue contact is measured and reliably calibrated in assessing and determining the applied force. The capacitive force sensor has a first plate affixed to a tissue contact portion of the catheter, a second plate configured for contact with the tissue, and an elastically compressible dielectric between the first and second plates, wherein the force sensor has a first capacitance when the first and second plates are separated by a first distance, and the force sensor has a second capacitance when the first and second plates are separated by a second different from the first distance.