Fetal ECG Extraction via Maternal Abdomen Signal Subtraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for monitoring fetal electrocardiogram (ECG) signals are invasive or lack non-invasive solutions for continuous monitoring throughout pregnancy and labor, necessitating improved extraction techniques.
Innovation Solution
A system and method utilizing multiple measurement vectors and sparse signal estimation frameworks to isolate the fetal ECG signal from abdominal ECG recordings by exploiting support similarities between signals, involving electrode placement on the mother's chest and abdomen, and processing using analog and digital circuitry to subtract the maternal ECG component and combine fetal ECG estimates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If invasive methods such as coupling an electrode onto the fetal scalp are used to monitor FECG during labor, then measurement precision is improved, but ease of operation deteriorates and object-affected harmful factors increase
Solution Approach 1:
The patent uses the maternal abdomen as an intermediary medium to capture FECG signals. Electromagnetic fields generated by the fetal heart propagate through the uterine wall and abdominal tissues to be detected by electrodes placed on the maternal abdomen, eliminating the need for direct fetal contact while preserving signal detectability
Solution Approach 2:
The patent replaces direct mechanical contact with the fetus (invasive electrode attachment) with electromagnetic field detection through maternal tissues. This substitution allows non-invasive measurement while maintaining the ability to detect FECG signals through the abdominal wall
2Object-affected harmful factors
If non-invasive abdominal ECG monitoring is used to monitor FECG throughout pregnancy and labor, then ease of operation is improved and object-affected harmful factors are reduced, but measurement precision deteriorates due to signal contamination
Solution Approach 1:
The patent segments the composite abdominal ECG signal into distinct maternal and fetal components through signal processing. By separating the MECG and FECG signals mathematically, the system can extract the fetal component with sufficient precision despite the initial signal contamination
Solution Approach 2:
The patent extracts the FECG signal from the composite abdominal ECG by removing the MECG component. Through signal processing techniques, the fetal ECG is isolated and extracted from the mixed signal, achieving measurement precision comparable to invasive methods
3Device complexity
If single-channel abdominal ECG data is used to estimate fetal ECG using sparse decomposition, then device complexity is reduced, but measurement precision deteriorates due to signal interference
Solution Approach 1:
The patent applies partial action by using only the necessary components of the signal processing framework. Sparse decomposition is applied selectively to extract FECG from abdominal ECG without requiring full multi-channel processing, achieving adequate precision with reduced complexity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of estimating fetal electrocardiogram (FECG) signals utilizes a plurality of ECG signals measured along the mother's abdomen. The method includes defining an MECG (ECG) dictionary of symbols and projecting the plurality of abdominal ECG signals onto the MECG dictionary to estimate MECG signals within each of the plurality of abdominal ECG signals. The estimated MECG signals are subtracted from the plurality of measured abdominal ECG signals to estimate FECG signals and the plurality of estimated FECG signals are combined to generate a representation of the FECG source signal.