Catheter Electrode Contact Detection Using Multi-Frequency Impedance
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Solution Overview
Problem
Current medical three-dimensional positioning systems struggle to accurately determine the relative position and contact between invasion devices, such as catheters, and the tissue in body cavities like heart chambers or renal arteries, necessitating a method for easy and practical contact identification.
Innovation Solution
A method and system that utilize impedance measurements at different frequencies to calculate an impedance frequency response coefficient, determining a contact index (CI) between electrodes and tissue, using working and reference electrodes on catheters, to assess contact status and extent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional positioning methods are used, then the basic positioning function is provided, but the contact identification between invasion device and tissue is inaccurate and difficult to operate
Solution Approach 1:
The patent changes the measurement parameter from single-frequency impedance to multi-frequency impedance spectroscopy. By measuring impedance at multiple frequencies (e.g., 1kHz, 10kHz, 100kHz) and analyzing the frequency response characteristics, the system achieves more accurate contact identification. The impedance frequency response coefficient calculation provides a comprehensive parameter that reflects tissue contact status better than traditional single-point impedance measurement.
Solution Approach 2:
The patent replaces mechanical contact sensing with electrical impedance-based detection. Instead of relying on mechanical sensors or visual confirmation, the system uses electrical impedance measurements at different frequencies to infer contact status. The impedance frequency response coefficient serves as an electrical indicator that substitutes for complex mechanical positioning systems, simplifying the overall system while improving accuracy.
2Measurement precision
If multi-frequency impedance measurement is implemented, then contact identification accuracy is improved, but system complexity increases
Solution Approach 1:
The patent makes the impedance measurement system multi-functional by using the same electrode structure for both traditional single-frequency impedance measurement and new multi-frequency spectroscopy. The existing electrodes on the invasion device can perform both functions, eliminating the need for separate contact sensing components. This universality reduces system complexity despite the enhanced measurement capability.
Solution Approach 2:
The patent performs preliminary impedance measurements at multiple frequencies and stores the frequency response characteristics before final contact determination. By pre-calculating the impedance frequency response coefficient and establishing reference values in advance, the system simplifies the real-time contact detection process. The preliminary data processing reduces the computational burden during actual operation.
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 accurate and reliable identification of electrode contact with tissue, enhancing the precision of catheter positioning within body cavities by displaying contact status with color differences, improving operational efficiency.
Implementation Method 1
acquiring an impedance between the electrodes on a body cavity invasion device at different frequencies; determining, according to the acquired impedance between the electrodes, an impedance frequency response coefficient between the electrodes
Data Source
AI summary
A method and system for identifying the contact between electrodes and a tissue includes acquiring an impedance between the electrodes on a body cavity invasion device at different frequencies, determining, according to the acquired impedance between the electrodes, an impedance frequency response coefficient between the electrodes, and determining, according to the impedance frequency response coefficient, the contact condition between the electrodes and a tissue in a body cavity. The body cavity invasion device includes a catheter. A plurality of electrodes are disposed at a distal end of the invasive catheter. The contact condition includes whether the electrodes are in contact with the surface of the body cavity and the extent of the contact.