Fetal ECG Monitoring via Maternal Signal Subtraction
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Solution Overview
Problem
Current systems for monitoring fetal and maternal cardiac activity during pregnancy face challenges in accurately distinguishing fetal heart signals from maternal signals due to factors like fetal movement, maternal anatomy, and varying signal-to-noise ratios, leading to potential inaccuracies in fetal heart rate monitoring.
Innovation Solution
A system comprising electrocardiogram (ECG) and phonocardiogram (PCG) sensors integrated into a garment, along with a programmed computer system that uses digital signal filtering, non-linear subtraction procedures, and Independent-Component-Analysis to isolate and process fetal heart signals, improving signal-to-noise ratios and accurately detecting fetal heart rate and variability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ECG and PCG sensors are used to monitor fetal cardiac activity, then continuous non-invasive monitoring is achieved, but accurate distinction between fetal and maternal signals becomes difficult
Solution Approach 1:
The patent segments the maternal ECG signal into discrete beats using detected R-peaks as markers. Each beat is divided into P-QRS-T complexes that can be individually analyzed and subtracted. This segmentation allows the system to process and remove maternal cardiac contributions in a systematic way, isolating the fetal signal components.
Solution Approach 2:
The patent extracts the maternal ECG contribution from the composite signal by identifying and removing P-QRS-T complexes based on detected R-peaks. By taking out the maternal signal components systematically, the fetal ECG and PCG signals can be isolated and analyzed separately, resolving the mixing problem.
Solution Approach 3:
The patent uses an intermediary approach by employing multiple sensors (ECG electrodes and acoustic PCG sensors) that capture different aspects of cardiac activity. The ECG provides electrical timing information while PCG provides acoustic verification, serving as intermediary measurements that help distinguish fetal from maternal origins through complementary data.
2Measurement precision
If multiple sensors are used to improve signal detection, then monitoring accuracy improves, but system complexity increases
Solution Approach 1:
The patent merges ECG and PCG sensor data into a unified analysis framework. By combining electrical (ECG) and acoustic (PCG) measurements, the system cross-validates fetal and maternal cardiac events, improving detection precision while managing complexity through integrated processing of complementary signal types.
Solution Approach 2:
The patent implements a multi-functional processing system that handles both ECG and PCG signals through a unified algorithmic framework. The same computational infrastructure processes both sensor types, performing maternal signal removal, fetal signal extraction, and heart rate calculation, thereby reducing overall system complexity despite multiple input sources.
3Reliability
If continuous monitoring is implemented, then fetal health assessment improves, but signal-to-noise ratio varies leading to potential inaccuracies
Solution Approach 1:
The patent implements continuous monitoring by continuously detecting R-peaks in the ECG signal and systematically processing each detected beat. The maternal signal removal and fetal signal extraction processes operate continuously as new data arrives, ensuring uninterrupted fetal health assessment despite varying signal conditions.
Solution Approach 2:
The patent employs feedback mechanisms where detected fetal heart rate and variability metrics are continuously monitored and can trigger alerts or adjustments. The system uses feedback from the signal processing pipeline to verify detection accuracy and maintain reliability even when signal-to-noise ratio fluctuates during continuous 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
The system provides continuous, non-invasive, and accurate monitoring of fetal heart activity, enhancing the detection of fetal heart rate and variability by effectively isolating fetal signals from maternal interference, thereby improving prenatal care.
Implementation Method 1
at least one electrocardiogram sensor configured to contact the skin of the abdomen of a pregnant human subject and detect fetal and maternal cardiac electrical activity
Implementation Method 2
at least one acoustic sensor configured to contact the skin of the abdomen of a pregnant human subject and detect fetal and maternal cardiac sounds
Data Source
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AI summary
The invention provides systems and methods for monitoring the wellbeing of a fetus by the non-invasive detection and analysis of fetal cardiac electrical activity data.