Multi-Frequency Impedance for Accurate Probe Location Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing impedance-based catheter location-tracking systems face difficulties in accurately determining the location of probes within an organ when multiple probes are present, as they introduce capacitive impedance that deviates from calibrated values, leading to incorrect location estimation.
Innovation Solution
The method employs zero-frequency impedance measurements at two different electrical frequencies to estimate the location of a probe by correlating probe zero-frequency impedance with stored calibration zero-frequency impedance, reducing capacitive distortion and enabling accurate tracking even with multiple probes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple probes are present in the organ for simultaneous tracking, then the system can perform multiple diagnostic or therapeutic functions, but capacitive impedance is introduced that causes deviation from calibrated impedance values, leading to inaccurate location estimation
Solution Approach 1:
The patent applies parameter changes by transitioning from single-frequency impedance measurements to multi-frequency impedance measurements. By measuring impedance at multiple frequencies and using frequency-dependent analysis, the system can distinguish between capacitive effects (which vary with frequency) and resistive effects (which are more stable), thereby compensating for the capacitive distortion introduced by multiple probes and maintaining accurate location estimation
Solution Approach 2:
The patent introduces an intermediary computational process that acts as a mediator between the raw impedance measurements and location estimation. This intermediary step involves calculating impedance magnitudes at multiple frequencies, analyzing the frequency dependence, and compensating for capacitive effects before determining probe location, thus isolating the location estimation from the distorting capacitive influences of multiple probes
2Ease of operation
If traditional single-frequency impedance-based location tracking is used, then the system is simple to operate, but capacitive distortion from multiple probes causes incorrect location estimation
Solution Approach 1:
The system changes the measurement parameter from single-frequency to multi-frequency impedance measurements. This allows the system to maintain ease of operation while improving measurement precision, as the additional frequency measurements enable the system to identify and compensate for capacitive distortion automatically through frequency-dependent analysis
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
This approach allows for precise location estimation of probes in organs, mitigating capacitive effects and simplifying multi-probe tracking procedures, such as in cardiac catheterization, without requiring additional location tracking techniques.
Implementation Method 1
measuring one or more first impedance-magnitudes, between a probe located at a location in an organ of a patient and one or more body-surface electrodes, at a first electrical frequency. One or more second impedance-magnitudes, between the probe located at the location and the one or more body-surface electrodes, are measured at a second electrical frequency
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A method for location tracking, includes measuring one or more first impedance-magnitudes, between a probe located at a location in an organ of a patient and one or more body-surface electrodes, at a first electrical frequency. One or more second impedance-magnitudes, between the probe located at the location and the one or more body-surface electrodes, are measured at a second electrical frequency. Based on the measured first and second impedance-magnitudes, one or more probe zero-frequency impedance-magnitudes between the probe and the one or more body-surface electrodes are estimated. The location of the probe in the organ is estimated based on the one or more probe zero-frequency impedance-magnitudes.