Blood Flow Index Calculation Using Camera-Based Pulse Wave Delay
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Solution Overview
Problem
Existing methods for measuring blood pressure and pulse wave velocity require dedicated hardware, making it impossible to measure these indices without extra equipment, such as electrocardiographic wave detecting electrodes or phototransistors, which are not typically found in general wrist watches.
Innovation Solution
A blood flow index calculating method and apparatus that uses a portable terminal, such as a mobile phone or digital camera, to detect pulse waves from images of the face and hand, calculating an index related to blood flow without the need for additional hardware by analyzing the delay between pulse wave patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dedicated hardware such as electrocardiographic wave detecting electrodes or phototransistors is used to measure blood pressure and pulse wave velocity, then measurement precision is improved, but device complexity increases and ease of operation deteriorates
Solution Approach 1:
The patent replaces dedicated hardware sensors (electrocardiographic electrodes, phototransistors) with a camera-based optical system. The camera captures images of the subject's face and hand, and pulse wave information is extracted through image processing algorithms rather than direct electrical or optical sensing, thereby eliminating the need for specialized medical-grade hardware components.
Solution Approach 2:
The patent uses a standard camera to capture visual images of blood flow changes in the face and hand, creating a visual copy of the physiological phenomenon. These images are then processed to extract pulse wave timing information, effectively copying the function of dedicated sensors using a more accessible device.
2Measurement precision
If dedicated hardware is installed to enable blood pressure measurement, then measurement precision is improved, but ease of operation worsens due to the need for special equipment
Solution Approach 1:
The patent makes the camera serve multiple functions: it not only captures photos and videos for general use but also functions as a pulse wave sensor for health monitoring. By extracting physiological information from regular camera images, the system enables blood pressure and pulse wave velocity measurement using a device everyone already possesses, greatly improving accessibility and ease of use.
3Ease of operation
If standard portable devices are used without extra hardware, then ease of operation is improved, but measurement precision deteriorates
Solution Approach 1:
The patent divides the face and hand regions in captured images into multiple analysis zones, tracking blood flow changes in different areas separately. By segmenting the image analysis and combining information from multiple regions (face, hand, fingers), the system compensates for the lower precision of standard camera sensors through spatial diversification of measurements.
Solution Approach 2:
The patent introduces image processing algorithms as an intermediary between the camera and the physiological measurement. These algorithms enhance the extraction of pulse wave signals from regular images, acting as a mediator that bridges the gap between standard device capabilities and medical-grade measurement requirements through sophisticated signal processing.
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
Enables the calculation of blood flow indices like pulse wave velocity and blood pressure using standard portable devices, eliminating the need for extra hardware and improving user convenience.
Implementation Method 1
detect pulse waves from images of the face and hand
Data Source
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AI summary
A blood flow index calculating apparatus (10) obtains an image, in which a first site of a living body and a second site of the living body are captured by a camera, the first site being a part of the living body of a subject, and the second site being a site different from the first site. Further, the blood flow index calculating apparatus (10) extracts an area of the first site of the living body and an area of the second site of the living body, the areas being included in the image. Furthermore, a pulse wave pattern of the first site of the living body is detected from the area of the first site of the living body and a pulse wave pattern of the second site of the living body is detected from the area of the second site of the living body. Moreover, the blood flow index calculating apparatus (10) calculates a delay amount from the pulse wave pattern of the first site of the living body and the pulse wave pattern of the second site of the living body. In addition, the blood flow index calculating apparatus (10) calculates an index related to blood flow by using the delay amount.