Blood Pressure Waveform Decomposition for Noise-Robust Measurement
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Solution Overview
Problem
Existing blood pressure measurement methods using oscillometric methods suffer from accuracy issues due to noise in pulse waveforms, which are influenced by cuff wrapping and positioning, necessitating data collection and calibration to set parameters, but these measures do not guarantee error reduction.
Innovation Solution
A blood pressure meter that decomposes cuff and pulse waveforms into multiple feature value waveforms using Wave-U-Net, employing a trained model with machine learning to measure blood pressure without data collection or calibration, leveraging global and local features to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If data collection and calibration are performed to set parameters of the blood pressure measurement algorithm, then measurement accuracy may be improved, but measurement time and operational complexity increase
Solution Approach 1:
The patent applies preliminary action by pre-training the deep learning model using extensive data collection and calibration before actual measurement. The model is trained in advance on diverse pulse waveform data to learn the relationship between waveform features and blood pressure, so that during actual measurement, the system can directly use the pre-trained model without requiring time-consuming data collection or calibration procedures. This resolves the contradiction by shifting the data collection and calibration work to a preliminary phase, making the measurement process faster while maintaining accuracy.
2Measurement precision
If data collection and calibration are performed to set parameters of the blood pressure measurement algorithm, then measurement accuracy may be improved, but the complexity of the measurement process increases
Solution Approach 1:
The patent applies self-service by enabling the pre-trained deep learning model to automatically process pulse waveform data and output blood pressure measurements without requiring manual intervention for parameter setting or calibration. The model autonomously learns from the input waveform and produces measurements directly, eliminating the need for complex manual calibration procedures. This resolves the contradiction by replacing complex manual measurement process with an automated self-service system that maintains accuracy while reducing operational complexity.
3Measurement precision
If the pulse wave includes noise due to cuff wrapping and positioning, then measurement accuracy decreases, but suppressing noise requires additional data collection and calibration
Solution Approach 1:
The patent applies the blessing in disguise principle by converting the harmful noise in pulse waveforms into beneficial training data for the deep learning model. Instead of attempting to eliminate noise through additional data collection or calibration, the system uses the noisy waveforms as part of the training data, teaching the model to recognize and filter noise patterns while extracting useful blood pressure information. The model learns to distinguish between noise and meaningful signal features, thereby converting the previously harmful noise into a factor that improves the model's robustness and accuracy in real-world conditions.
Data Source
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AI summary
The blood pressure meter includes: a cuff to be wrapped around an arm of a subject to be measured; a detection unit that detects cuff pressure; a decomposition unit that acquires, based on the cuff pressure, a first waveform indicating a time-series change in a feature value related to blood pressure of the subject to be measured and decomposes the first waveform into a plurality of second waveforms indicating two or more different feature values; a trained model constructed by machine learning in which the second waveforms for a plurality of test subjects are used as explanatory variables and blood pressure actually measured by auscultation is used as an objective variable; a measurement unit that measures the blood pressure of the subject by inputting the plurality of second waveforms into the trained model; and an output unit that outputs the blood pressure measured by the measurement unit.