Pulse Wave Amplitude Extraction for Cardiovascular Feature Estimation
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Solution Overview
Problem
Current bio-information estimation methods, such as those using PPG sensors, face challenges in accurately determining blood pressure and other cardiovascular metrics due to distortion from superposition of element waveforms in pulse wave signals, leading to inaccurate feature extraction and estimation.
Innovation Solution
The proposed solution involves a processor that extracts specific amplitudes from pulse wave signals corresponding to different element waveforms and corrects these amplitudes by subtracting a predetermined percentage of adjacent waveform amplitudes, allowing for more accurate estimation of bio-information like blood pressure, vascular age, and other cardiovascular metrics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If amplitude extraction is performed directly from superposed pulse wave signals, then the processing is simple, but the measurement precision deteriorates due to waveform distortion
Solution Approach 1:
The pulse wave signal is segmented into multiple element waveforms (first, second, third element waveforms) corresponding to different physiological events. By dividing the superposed signal into constituent elements, the system can extract amplitudes from individual waveforms rather than the distorted superposition, thereby improving measurement precision while maintaining reasonable processing complexity
Solution Approach 2:
The invention extracts specific amplitude values (P1, P2, P3) from individual element waveforms within the superposed pulse wave signal. By taking out the relevant amplitude information from each element waveform separately, the system avoids the distortion that would result from analyzing the superposed signal as a whole, thus improving amplitude extraction accuracy
2Loss of information
If reflection waves are included in the pulse wave signal, then the signal contains more physiological information, but the reliability of blood pressure estimation deteriorates due to waveform distortion
Solution Approach 1:
The invention converts the harmful effect of reflection wave superposition into a beneficial feature by using the amplitude relationships between different element waveforms. The corrected amplitude calculation uses the reflection wave amplitude (P3) to adjust the second element waveform amplitude (P2), transforming the distortion problem into a source of additional physiological information that improves blood pressure estimation reliability
Solution Approach 2:
The system uses feedback from the third element waveform amplitude (P3) to correct the second element waveform amplitude (P2). By applying the correction formula that incorporates P3, the system continuously adjusts the amplitude values based on the actual waveform characteristics, thereby improving the reliability of blood pressure estimation while retaining information from all wave components
Data Source
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AI summary
Provided is an apparatus for estimating bio-information. The apparatus for estimating bio-information according to an embodiment includes a processor configured to obtain a pulse wave signal from a user; extract components of a plurality of element waveforms which constitute a waveform of the pulse wave signal; and obtain a cardiovascular feature based on the extracted components of the plurality of element waveforms. The processor is configured to extract a component of at least one element waveform based on a component of an adjacent element waveform.