Wearable Sensor Light Sensitivity via Segmented LED Arrays
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Solution Overview
Problem
Conventional wearable sensors have limited light sensitivity due to space constraints and scattering of light in the body, making them unsuitable for efficient light measurement and analysis of physiological signs.
Innovation Solution
A wearable sensor design featuring a flexible substrate with arrays of organic or inorganic light emitting diodes and semiconductor sensors, including switching elements with amorphous silicon, low-temperature polysilicon, or indium gallium zinc oxide, arranged to enhance light sensitivity and wearability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional light emitting diodes are used in wearable sensors, then the device can measure physiological signs, but the space allocation becomes insufficient and light sensitivity decreases
Solution Approach 1:
The sensor device is divided into multiple independent sensor elements, each comprising a light emitter and a reflected light receiver. This segmentation allows for compact arrangement of multiple sensing units within limited space while maintaining individual light sensitivity for each element.
Solution Approach 2:
The patent transitions from conventional two-dimensional arrangement to a stacked three-dimensional configuration where light emitters and reflected light receivers are positioned at different vertical levels. This dimensional change enables closer packing of components while preserving optical path integrity and light sensitivity.
2Loss of information
If light is emitted into the living body for measurement, then physiological information can be obtained, but light scattering reduces the received signal intensity
Solution Approach 1:
A light guide member is introduced as an intermediary component to capture scattered light from the living body and redirect it toward the reflected light receiver. This mediator increases the probability that scattered photons will still be detected, thereby reducing information loss despite scattering effects.
Solution Approach 2:
The patent converts the harmful effect of light scattering into a beneficial feature by using the scattered light itself as the measurement signal. The reflected light receiver is specifically designed to detect light that has scattered within the living body, transforming what was previously considered signal degradation into the primary measurement mechanism.
3Measurement precision
If multiple light sources and receivers are installed to improve light sensitivity, then measurement accuracy increases, but device complexity and manufacturing difficulty increase
Solution Approach 1:
Each sensor element is designed as a universal module that can be replicated and arranged in arrays. The standardized design of light emitters, reflected light receivers, and supporting substrates allows for scalable manufacturing without proportionally increasing device complexity, as each module performs the same function.
Solution Approach 2:
Multiple functional components are merged into integrated sensor elements where light emitters and reflected light receivers are combined in close proximity on the same supporting substrate. This merging reduces the overall number of discrete components and simplifies assembly while maintaining high light sensitivity through the combined functionality of each element.
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 achieves improved light sensitivity and accuracy in measuring physiological signs with enhanced wearability, capable of efficiently receiving light reflected from the body, reducing the impact of varying blood vessel distributions.
Implementation Method 1
a light emitter which is an organic light emitting diode or an inorganic light emitting diode
Implementation Method 2
reflected light receiver configured to measure a quantity of light emitted from the light emitter and reflected in a living body of a subject
Implementation Method 3
a photoelectric conversion layer for reflected light reception
Data Source
AI summary
Provided is a wearable sensor with enhanced light sensitivity. The wearable sensor is to be worn by a subject, the wearable sensor including: a supporting substrate; and sensor elements placed on the supporting substrate. The sensor elements each include: a light emitter which is an organic light emitting diode or an inorganic light emitting diode; and a reflected light receiver configured to measure a quantity of light emitted from the light emitter and reflected in a living body of a subject. Preferably, in a plan view, at least part of the reflected light receiver does not overlap the light emitter.