Flexible Sensor Circuit Board for Stable Pulse Wave Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The pulse wave measuring method faces challenges in stability and accuracy due to movement of the subject, which can displace the sensor or cause blood vessels to move within the body, making it difficult to obtain reliable measurements.
Innovation Solution
A sensor design featuring a flexible circuit board with light-emitting and photodetector elements mounted in a face-down configuration, allowing for flexible positioning and integration with optical path changing elements like lenses, enabling accurate and stable pulse wave measurement by maintaining contact with the wrist's curve and reducing pressure on blood vessels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the sensor is placed on the arm or leg for pulse wave measurement, then the measurement is easier to perform than ECG, but the measurement stability and accuracy deteriorates due to subject movement
Solution Approach 1:
The circuit board is designed with a curved surface that conforms to the contour of the subject's body part (arm or leg). This curved configuration allows the sensor to maintain stable contact with the skin even when the subject moves, preventing sensor displacement and maintaining measurement reliability while preserving the ease of placement on accessible body parts
2Ease of operation
If the sensor is placed on the arm or leg for pulse wave measurement, then the measurement is easier to perform than ECG, but the measurement accuracy deteriorates due to blood vessel movement within the body
Solution Approach 1:
The curved circuit board conforms to the body's contour, distributing pressure evenly across the measurement area. This prevents excessive localized pressure that could displace blood vessels, while maintaining sufficient contact for accurate light transmission detection, thus preserving measurement precision during subject movement
3Device complexity
If a rigid circuit board is used to mount the light emitting and photodetector elements, then the sensor structure is simpler, but the sensor cannot conform to the body's curve, reducing measurement accuracy
Solution Approach 1:
The circuit board is constructed from flexible materials that allow it to bend and conform to the curved surface of the subject's body. This flexible configuration enables the sensor to adapt to body contours for accurate measurement while maintaining a relatively simple integrated structure without requiring additional rigid support components
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 sensor system provides stable and accurate pulse wave measurements even with subject movement, enhancing measurement accuracy and reducing the need for additional packaging, allowing for precise tracking of pulse wave velocity and bio-information calculation.
Implementation Method 1
a light emitting element for emitting light to a test site
Implementation Method 2
a photodetector element for receiving at least one of reflection light and scattered light from the test site
Implementation Method 3
The light-transmitting portion may be provided with an optical path changing element for changing at least one of an optical path of the light emitted by the light emitting element and an optical path of the light to be received by the photodetector element
Implementation Method 4
The optical path changing element may be any one of a spherical lens, an aspherical lens, a Fresnel lens, a cylindrical lens, and a prism
Data Source
AI summary
A sensor includes a light emitting element, a photodetector element for receiving light emitted by the light emitting element, and a circuit board having the light emitting element and the photodetector element mounted thereon. A light emitting surface of the light emitting element is facing the circuit board which is provided with a light-transmitting portion for transmitting the light emitted by the light emitting element.