Cuffless Blood Pressure Detection Using PPG Signal Calibration
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Solution Overview
Problem
Current blood pressure detection methods, such as cuff-type detection methods, are not portable and cannot provide continuous, accurate measurements suitable for hypertensive patients, requiring external devices for calibration and being cumbersome for frequent use.
Innovation Solution
A cuffless blood pressure detection method using photo plethysmography (PPG) signals, where initial calibration is obtained by processing a first PPG signal and first pressure, allowing subsequent blood pressure measurements to be made without external assistance, improving accuracy and user experience by eliminating the need for repeated pressure application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a cuff-type detection method is used to achieve accurate blood pressure measurement, then measurement precision is improved, but device complexity and portability are worsened
Solution Approach 1:
The patent replaces the mechanical cuff-based oscillometric detection system with an optical PPG-based detection system. The blood pressure detection apparatus uses a light source and photodetector to capture pulse wave signals optically, eliminating the need for mechanical inflation and deflation of a cuff. This substitution maintains measurement accuracy while dramatically improving portability and enabling continuous monitoring.
Solution Approach 2:
The apparatus performs self-calibration by automatically determining calibration parameters from the user's own PPG signals without requiring external calibration devices or manual intervention. The system extracts calibration information from the relationship between PPG signal amplitude and applied pressure, then uses this self-derived calibration data to convert subsequent PPG signals into accurate blood pressure readings, eliminating dependency on external sphygmomanometers.
2Measurement precision
If external calibration devices are used to improve blood pressure measurement accuracy, then measurement precision is improved, but ease of operation is worsened
Solution Approach 1:
The system performs automatic self-calibration by extracting calibration parameters directly from the user's PPG signals and the relationship with applied pressure. The calibration process is fully automated, requiring no manual intervention, external devices, or professional operation. The apparatus independently determines the calibration curve by analyzing how PPG signal amplitude changes with applied pressure, then uses this self-derived calibration to accurately measure blood pressure in subsequent measurements.
Solution Approach 2:
The system performs calibration in advance by determining calibration parameters from an initial set of PPG signals collected under known pressure conditions. This preliminary calibration action stores the relationship between PPG amplitude and blood pressure, enabling subsequent rapid and accurate blood pressure measurements without requiring repeated external calibration devices or manual procedures.
3Measurement precision
If pressure is applied repeatedly to obtain calibration data, then measurement precision is improved, but user experience is worsened
Solution Approach 1:
The system performs the pressure application and calibration data collection only once during an initial calibration phase. The calibration parameters derived from this single pressure application are then stored and reused for all subsequent blood pressure measurements. This eliminates the need for repeated pressure application, maintaining high measurement accuracy while significantly improving user comfort and experience during ongoing monitoring.
Solution Approach 2:
After the initial calibration phase, the system enables continuous blood pressure monitoring using the stored calibration parameters without requiring repeated pressure application. The PPG sensor continuously captures pulse wave signals, and the system continuously converts these signals into blood pressure readings using the pre-established calibration relationship, providing uninterrupted monitoring comfort and convenience.
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 method provides continuous, non-invasive, and accurate blood pressure monitoring, enhancing user convenience and experience by eliminating the need for external devices and reducing the frequency of pressure application, while maintaining high measurement accuracy.
Implementation Method 1
acquiring a second photo plethysmography (PPG) signal, and processing the second PPG signal to obtain the user's initial blood pressure
Data Source
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AI summary
A blood pressure detection method (100), an apparatus (101), and an electronic device (10) are provided, having relatively accurate blood pressure detection results and are convenient to detect. The blood pressure detection method (100) is applied to a blood pressure detection apparatus (101), and the method includes: acquiring blood pressure calibration information, the blood pressure calibration information being information obtained by processing according to a first pressure acting on a user and a first PPG signal when the first pressure acts on the user (S110); acquiring a second PPG signal, and processing according to the second PPG signal to obtain the user's initial blood pressure (S120); and calibrating the initial blood pressure according to the blood pressure calibration information, and using the blood pressure obtained by calibration as the blood pressure of the user (S130). In the pressure detection method (100), there is no need to resort to an external device such as a blood pressure meter for assistance. The relatively accurate user pressure can be obtained by acquiring the blood pressure calibration information determined according to the first PPG signal and the first pressure directly according to the blood pressure detection apparatus per se, obtaining the initial blood pressure determined according to the second PPG signal, and calibrating the initial blood pressure by the blood pressure calibration information.