Pulse Wave Measurement Using Optical Displacement and Airbag Pressure
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Solution Overview
Problem
Existing pulse diagnosis devices suffer from measurement errors due to non-linear relationships between operator-induced depression depth and static pressure, leading to inaccurate physiological state assessments.
Innovation Solution
A pulse wave measuring device that uses an airbag with a pressure control module, displacement sensing module, and optional scanning position control module to accurately measure pulse waves by adjusting pressure and optimizing signal-to-noise ratio at specific positions on the wrist, particularly at Cun, Guan, and Chi points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure film sensor is used with airbag to adjust depression depth, then pulse wave measurement can be performed, but measurement precision deteriorates due to non-linear relationship between static pressure and depression depth
Solution Approach 1:
The patent replaces the mechanical pressure film sensor system with an optical measurement system. A displacement sensor detects the position of a reflective marker on the wrist, and a camera captures images to calculate displacement based on marker position changes. This optical substitution eliminates the non-linear pressure-depression relationship, providing linear and reliable displacement measurements for pulse wave analysis.
2Ease of operation
If operator manually adjusts airbag pressure to achieve optimal depression depth, then pulse location can be targeted, but measurement precision deteriorates due to varying operator habits
Solution Approach 1:
The system performs self-positioning and self-measurement without requiring operator skill or manual adjustment. The displacement sensor and camera automatically detect the reflective marker on the wrist and calculate displacement. The system independently completes the measurement process, eliminating operator habit variations and ensuring consistent measurement precision across different users.
Solution Approach 2:
The patent changes the measurement parameter from pressure-based (non-linear) to displacement-based (linear). By tracking the position changes of the reflective marker optically, the system achieves linear relationship between measured parameter and actual displacement, improving measurement precision and eliminating the need for manual pressure adjustment.
3Loss of information
If pressure film sensor measures dynamic pressure, then pulse signal can be obtained, but signal-to-noise ratio deteriorates due to noise interference
Solution Approach 1:
The patent replaces mechanical pressure sensing with optical displacement detection. The displacement sensor and camera system tracks the reflective marker's position changes, converting mechanical pulse movements into optical displacement signals. This substitution avoids the noise interference affecting pressure sensors and provides cleaner signal quality with better signal-to-noise ratio.
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 device provides precise measurement of pulse wave characteristics, enhancing the accuracy of physiological state assessment by ensuring optimal signal detection and reducing measurement errors.
Implementation Method 1
uses a photoelectric displacement sensor to accurately measure pulse wave characteristics
Data Source
AI summary
A Chinese pulse wave measuring device is provided, which includes an airbag, a pressure control module, a displacement sensing module, a scanning position control module, and a computing device. The above-mentioned pressure control module, displacement sensing module, and scanning position control module are respectively communicationally connected to the computing device, and the pump of the pressure control module is connected to the airbag through gas tube and valve. A method of using the above-mentioned pulse wave measuring device is also provided.