Planar Spring Force Sensor for Catheter Contact Measurement
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Solution Overview
Problem
Current methods for verifying electrode contact with cardiac tissue during ablation procedures for treating arrhythmias are inadequate, as they fail to provide precise and reliable measurements of contact force, which can lead to inconsistent delivery of ablation energy and potential artifacts from poor tip contact.
Innovation Solution
A catheter system equipped with a contact force sensor, comprising a deformable helical spring and integrated radiofrequency coils, which measures contact force by analyzing the deformation of the spring and the amplitude of radiofrequency signals, providing accurate and real-time feedback on the force and orientation of the catheter tip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pressure transducer is used to measure contact force, then measurement capability is provided, but device complexity and cost increase
Solution Approach 1:
The patent combines the contact force sensing function with the existing catheter structure by integrating a deformable element directly into the catheter shaft. The deformable element's mechanical deformation under contact force is coupled with electromagnetic coils to generate electrical signals, merging mechanical sensing and electrical signal generation into a single integrated assembly, thereby reducing overall device complexity while maintaining measurement capability
Solution Approach 2:
The patent replaces traditional mechanical pressure transducers with an electromagnetic sensing mechanism. Instead of using a mechanical strain gauge or piezoelectric sensor, the invention uses a deformable element coupled with electromagnetic coils that convert mechanical deformation directly into electrical signals through electromagnetic induction, simplifying the mechanical components while achieving accurate force measurement
2Reliability
If electrode contact verification is improved, then ablation energy delivery consistency improves, but device complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the contact force sensor continuously monitors the force between the electrode and cardiac tissue, and this information is fed back to the control system. The control system uses this feedback to adjust ablation energy delivery parameters in real-time, ensuring consistent and reliable ablation while preventing overheating or ineffective treatment, thereby improving reliability without requiring complex external monitoring systems
Solution Approach 2:
The catheter assembly is designed to perform multiple functions: electrical signal delivery for ablation, contact force sensing, and real-time feedback control, all within a single integrated device. The deformable element serves both as a mechanical coupling component and as the sensing element, while the electromagnetic coils serve both for electromagnetic field generation and for signal detection, reducing the need for separate specialized components
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 system ensures stable and precise contact with cardiac tissue, allowing for consistent delivery of ablation energy and reducing the risk of artifacts, thereby improving the effectiveness of arrhythmia treatment by creating reliable non-conducting lesions.
Implementation Method 1
a deformable helical spring, which measures contact force by analyzing the deformation of the spring
Implementation Method 2
integrated radiofrequency coils, which measures contact force by analyzing the deformation of the spring and the amplitude of radiofrequency signals
Data Source
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AI summary
A flexible probe has an assembly in its distal end that includes a transmitter and a receiver that receives signals from the transmitter for sensing a position of the receiver relative to the transmitter. A pair of flat spring coils disposed between the transmitter and the receiver deform in response to pressure exerted on the distal tip when the distal tip engages a wall of a body cavity.