Catheter ECG Signal Synchronization Using Common Ground Offset Correction
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Solution Overview
Problem
Legacy catheter-based systems face issues with ground offset and timing desynchronization when processing unipolar ECG signals from modern diagnostic catheters with multiple electrodes, leading to inaccurate signal amplitudes and phase discrepancies.
Innovation Solution
An additional circuitry and processor configuration are introduced to assign a common electrical ground and timing reference, digitize unipolar signals, and estimate ground and timing offsets to synchronize and correct the signals, allowing accurate measurement of multiple unipolar ECG signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If unipolar ECG signals are processed using legacy catheter-based systems, then signal acquisition is possible, but ground offset and timing desynchronization cause inaccurate signal amplitudes and phase discrepancies
Solution Approach 1:
The patent introduces an intermediary processing stage that receives both analog unipolar signals and analog body-surface signals, converts them to digital domain, and performs offset estimation and correction. This intermediary digital signal processing unit acts as a mediator between the analog catheter signals and the legacy system, enabling accurate synchronization and amplitude measurement by eliminating ground offset and timing desynchronization issues.
2Productivity
If multiple unipolar electrodes are used in modern diagnostic catheters, then more ECG channels are available, but ground offset and timing desynchronization issues arise
Solution Approach 1:
The patent replaces complex analog signal processing and grounding schemes with digital signal processing. Instead of using complex analog circuitry to handle multiple unipolar electrodes and their associated ground references, the system converts all signals to digital domain where offset estimation and correction can be performed algorithmically, simplifying the overall system architecture while maintaining high channel count capability.
3Ease of operation
If analog unipolar signals are directly measured without digital conversion, then signal acquisition is simpler, but ground offset and timing reference issues cannot be corrected
Solution Approach 1:
The patent performs preliminary digital conversion of analog unipolar signals and analog body-surface signals before processing. By converting signals to digital domain early in the processing chain, the system enables subsequent offset estimation and correction operations that would be difficult or impossible to perform on analog signals. This preliminary digital conversion maintains operational simplicity while enabling precise amplitude measurement through algorithmic correction.
Data Source
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AI summary
A method includes receiving analog body-surface signal from body-surface electrode, and multiple analog unipolar signals from multiple unipolar electrodes of an invasive probe. A first unipolar electrode is assigned to serve as a common electrical ground and a common timing reference for the analog unipolar signals and the analog body-surface signal. The analog unipolar signals are digitized to produce digital unipolar signals sampled relative to a digital ground. Defined are an analog bipolar signal between the first unipolar electrode and a second unipolar electrode of the probe, and digital bipolar signal formed from the first unipolar electrode and the second unipolar electrode. Ground and timing offsets between the analog bipolar signal and the digital bipolar signal are estimated, while the first unipolar electrode is connected to the digital ground. The ground offset and the timing offset are applied in measuring a third unipolar signal, sensed by a third unipolar electrode.