Electrophysiology Signal Gain Control for DC Offset and Saturation
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Solution Overview
Problem
Current electrophysiology systems face challenges in achieving high fidelity intracardiac electrophysiological signals with improved noise performance while maintaining fast recovery from transient interferences during procedures like pacing and ablation, due to limitations in ADC gain caused by DC offset issues.
Innovation Solution
The system automatically adjusts the ADC gain inversely proportional to the DC component of the signal, using a monitoring element to generate a control signal that adjusts the gain setting, thereby optimizing noise performance and minimizing signal distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If ADC gain is increased to improve noise performance, then noise performance is improved, but DC offset causes signal saturation and loss
Solution Approach 1:
The patent implements dynamic gain adjustment by continuously monitoring the DC component of the electrophysiological signal and adjusting the ADC gain accordingly. The gain is increased when DC offset is low (during diagnostic phases) to improve noise performance, and decreased when DC offset is high (during ablation) to prevent signal saturation. This dynamic adaptation resolves the contradiction between noise performance and signal saturation.
Solution Approach 2:
The system changes the gain parameter of the ADC based on the detected DC component level. By monitoring the DC offset and adjusting the gain parameter in real-time, the system optimizes the balance between noise performance and prevention of signal saturation, allowing high gain during low DC offset conditions and low gain during high DC offset conditions.
2Device complexity
If fixed gain is used to simplify system design, then device complexity is reduced, but noise performance cannot be optimized across different procedural phases
Solution Approach 1:
The patent employs a feedback mechanism where the DC component of the signal is continuously monitored and used to control the ADC gain. This closed-loop feedback system automatically adjusts the gain to optimize noise performance during different procedural phases (diagnostic vs. ablation) without requiring complex manual intervention, resolving the contradiction between simplicity and optimized performance.
Solution Approach 2:
The system performs self-adjustment by automatically monitoring its own signal conditions and adjusting the ADC gain accordingly. The monitoring element detects the DC component and the system autonomously modifies the gain setting, eliminating the need for external manual adjustment and maintaining operational simplicity while achieving optimized noise performance.
3Reliability
If gain is decreased during ablation to prevent saturation, then signal saturation is prevented, but noise performance deteriorates
Solution Approach 1:
The system dynamically adjusts the ADC gain based on the procedural phase detected through DC component monitoring. During ablation when DC offset is high, the gain is automatically decreased to prevent signal saturation. During diagnostic phases when DC offset is low, the gain is increased to optimize noise performance. This dynamic behavior resolves the contradiction between preventing saturation and maintaining noise performance.
Solution Approach 2:
The system periodically monitors the DC component of the signal and adjusts the gain in response to changing conditions. This periodic adjustment ensures that the gain is optimized for each procedural phase (diagnostic vs. ablation), preventing saturation during ablation while maintaining low noise during diagnostic phases.
Data Source
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AI summary
The present invention relates to an electrophysiology system comprising one or more signal channels, wherein each signal channel is adapted for processing an electrophysiological signal along a signal path. The signal path extends from an input port configured for receiving the electrophysiological signal as an analog signal, via at least one adjustable gain element adapted for amplifying the electrophysiological signal with a gain according to a gain setting, and via an ADC element adapted for converting the analog signal into a digital signal corresponding to the electrophysiological signal, to an output port arranged for providing the digital signal as an output. The electrophysiology system further comprises a monitoring element configured for generating a monitoring signal representative of a magnitude of a DC component of the electrophysiological signal and a gain control element configured for generating a control signal in response to the monitoring signal. The control signal is adapted to control the gain setting of the adjustable gain element so as to cause a decrease in gain, if an increase in the magnitude of the DC component is determined; and/or an increase in gain, if a decrease in the magnitude of the DC component is determined.