Catheter Power Control via Contact Force Feedback
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Solution Overview
Problem
Invasive medical devices, such as catheters, face challenges in preventing undesired damage to heart tissue due to excessive contact force and RF energy during procedures like intracardiac radiofrequency ablation, where proper contact is necessary but excessive force or energy can cause tissue damage or perforation.
Innovation Solution
A catheterization system that includes a sensor assembly to detect contact force and a controller to adjust the power supplied to the catheter electrode based on detected force levels, reducing power when contact force increases and increasing power when force decreases, using a power control curve with hysteresis to manage energy delivery effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RF energy is applied to the electrode to ablate heart tissue, then therapeutic effect is achieved, but excessive RF energy may cause undesired damage to the heart tissue and even perforation of the heart wall
Solution Approach 1:
The system continuously monitors contact force between the electrode and heart tissue using a force sensor, and adjusts RF power delivery in real-time based on the measured contact force. When contact force increases indicating potential excessive pressure, the system automatically reduces or shuts off RF power to prevent tissue damage, while maintaining therapeutic effect when proper contact is detected
Solution Approach 2:
The RF power delivery is made dynamic rather than static, with the power level automatically adjusting based on real-time contact force measurements. The system transitions between different power states (off, reduced power, full power) depending on the contact force threshold being exceeded, allowing adaptive control that responds to changing clinical conditions
2Reliability
If contact force is increased to ensure proper electrode contact with the endocardium, then diagnostic function and therapeutic effect are improved, but excessive contact force may cause undesired damage to the heart tissue
Solution Approach 1:
The force sensor provides continuous feedback on contact force magnitude, allowing the system to detect when proper contact is achieved and when excessive force is applied. This feedback enables automatic adjustment of both contact force (through operator guidance) and RF power delivery to maintain safe operating parameters
Solution Approach 2:
The system automatically monitors and protects against excessive contact force without requiring continuous manual intervention. The force sensor and control system work together to self-regulate the interaction between electrode and tissue, reducing reliance on operator skill and experience while preventing damage
Data Source
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AI summary
A method for controlling an ablation power applied to a catheter includes: receiving, by a controller, a detected contact force from a sensor assembly of the catheter, the sensor assembly being configured to detect a contact force applied to the electrode; controlling, by the controller, a power supplied to an electrode of the catheter to have a deactivated power level when the detected contact force is less than a first threshold contact force; controlling, by the controller, the power supplied to the electrode of the catheter to have a first power level when the detected contact force is greater than the first threshold contact force; and controlling, by the controller, the power supplied to the electrode of the catheter to have a deactivated power level when the detected contact force is greater than a cutoff contact force, the cutoff contact force being greater than the first threshold contact force.