Balloon Catheter Electrode Contact Detection by Surface Temperature
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Solution Overview
Problem
Existing cardiac catheters lack efficient methods to determine whether electrodes are in physical contact with tissue during ablation procedures, requiring tedious and unsafe fluoroscopy for occlusion assessment.
Innovation Solution
A catheter system with expandable balloon electrodes and sensors measures transient changes in blood properties, such as temperature or impedance, to determine electrode-tissue contact, eliminating the need for fluoroscopy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluoroscopy is used to assess occlusion and electrode-tissue contact, then assessment can be performed, but patient exposure to radiation increases and the procedure becomes more complex
Solution Approach 1:
The patent replaces fluoroscopy (a radiation-based imaging system) with a mechanical/physical sensing system that measures pressure differential and temperature changes. Temperature sensors detect thermal changes caused by blood flow occlusion, while pressure sensors measure differential pressure across the balloon, providing a non-radiative method to assess occlusion and electrode-tissue contact
Solution Approach 2:
The patent introduces temperature and pressure sensors as intermediary devices that indirectly measure occlusion status. Instead of directly visualizing anatomy with fluoroscopy, the sensors detect physiological changes (temperature differential, pressure differential) that serve as intermediaries to infer occlusion and contact status
2Reliability
If fluoroscopy is used to determine electrode-tissue contact, then contact assessment can be performed, but device complexity and procedural time increase
Solution Approach 1:
The ablation balloon catheter integrates multiple functions: RF ablation delivery, temperature sensing, and pressure sensing. The same balloon structure that delivers therapeutic energy also houses sensors that provide diagnostic information about occlusion and tissue contact, eliminating the need for separate assessment procedures
Solution Approach 2:
The patent combines the ablation function and sensing function into a single integrated device. Temperature sensors and pressure sensors are embedded within the balloon structure, merging the therapeutic and diagnostic capabilities into one unified system that simultaneously performs ablation and monitors contact status
3Reliability
If temperature sensors are placed distal to the cryo-balloon to measure blood temperature changes, then occlusion quality can be assessed, but the measurement location may not accurately reflect electrode-tissue contact at the balloon surface
Solution Approach 1:
The patent places temperature sensors in direct contact with or in immediate proximity to the balloon surface at multiple locations corresponding to different electrodes. This local placement ensures that each sensor measures temperature changes specific to its associated electrode-tissue interface, providing precise contact detection for each ablation site
Solution Approach 2:
The patent divides the balloon into multiple segments or zones, each with its own temperature sensor and corresponding electrode. This segmentation allows independent monitoring of occlusion and contact status at each ablation site, enabling precise localization of contact problems to specific electrode positions
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
Provides real-time, safe, and accurate assessment of electrode-tissue contact, improving the effectiveness of cardiac ablation treatments like pulmonary vein isolation.
Implementation Method 1
one or more temperature sensors in proximity to each electrode, wherein the one or more temperature sensors are each configured to measure the characteristic of blood
Implementation Method 2
measuring a resulting transient change in blood properties
Data Source
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AI summary
A method includes positioning an expandable balloon, coupled to a distal end of a catheter, at a target location within an organ of a patient, the expandable balloon including multiple electrodes and one or more sensors in proximity to each electrode, wherein the one or more sensors are configured each to measure a characteristic of blood. The expandable balloon is expanded at the target location. A fluid is flowed through an inner lumen of the catheter and into the blood in a vicinity of each electrode. A dependence of the characteristic of blood on time is measured, via the one or more sensors, in proximity to each electrode. Using a processor, it is determined whether or not each electrode is in physical contact with tissue, based on the measured dependence of the characteristic of blood. An indication of whether or not each electrode is in physical contact with tissue is outputted to a user.