Guidewire Impedance Measurement Error Correction
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Solution Overview
Problem
Conventional impedance measurement methods for biological tissues face challenges in differentiating true impedance values from errors induced by the measuring tool, particularly due to shunt capacitance, which affects measurement accuracy and treatment efficacy.
Innovation Solution
The method involves using a third-terminal connection with an error correction electrode to create an electrical pathway that reduces or eliminates shunt capacitance errors by independently advancing two guidewires with electrodes into a tissue region and applying a voltage, allowing for accurate impedance measurement between them.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional two-terminal impedance measurement is used, then the measurement process is simple, but shunt capacitance causes significant measurement errors
Solution Approach 1:
The patent introduces a third terminal (error correction electrode) as an intermediary element that provides a reference path for measuring shunt capacitance. This third terminal acts as a mediator between the two measurement electrodes and the body, enabling separate measurement and compensation of the shunt capacitance error from the tissue impedance measurement.
Solution Approach 2:
The measurement process is segmented into separate components: the total measured impedance is divided into the tissue impedance component and the shunt capacitance component. By using the third terminal to measure the shunt capacitance separately, the total measurement is segmented into measurable parts that can be processed independently and then combined to obtain the true tissue impedance.
2Object-affected harmful factors
If guidewires with shielding material are used, then electromagnetic interference is reduced, but shunt capacitance between guidewires increases
Solution Approach 1:
The system uses the third terminal to continuously measure the shunt capacitance between guidewires and the body, providing feedback information about the error. This feedback is then used to compensate for the shunt capacitance effect in real-time, allowing the system to adapt to changes in shunt capacitance caused by different guidewire configurations and shielding materials.
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 provides more accurate in vivo tissue impedance measurements, reducing errors associated with shunt capacitance and improving the evaluation of tissue conditions and treatment implementation.
Implementation Method 1
A voltage is applied across the first and the second guidewires. The impedance of the tissue region between the first and the second guidewires is measured while using an electrical pathway created by the error correction electrode.
Implementation Method 2
The impedance of the tissue region between the first and the second guidewires is measured
Data Source
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AI summary
A method and apparatus for measuring an impedance of a tissue region inside a body of a patient. A first guidewire is advanced into a tissue region of a body of a patient, wherein the first guidewire comprises one or more electrodes electrically coupled to the tissue region. A second guidewire is advanced into the body, wherein the second guidewire comprises one or more electrodes electrically coupled to the tissue region of the body of the patient and spaced from the first guidewire. An error correction electrode is electrically coupled to the body. A voltage is applied across the first and the second guidewires. The impedance of the tissue region between the first and the second guidewires is measured while using an electrical pathway created by the error correction electrode.