Wearable EO-PPG Sensing for Higher Detection Accuracy
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Solution Overview
Problem
Conventional physiological signal detection devices in VR or AR applications suffer from inadequate detection accuracy.
Innovation Solution
A wearable device incorporating a light modulator, light source, light waveguide, light sensor, and processor, utilizing a variable refractive index EO crystal element to analyze phase changes in light communication signals for enhanced detection, and optionally combining EO detection with PPG detection for physiological information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional physiological signal detection devices are used in VR or AR applications, then the device structure is simple, but the detection accuracy is insufficient
Solution Approach 1:
The patent combines multiple detection functions (EO detection and PPG detection) into a single wearable device. The light modulator, light waveguide, and light sensor serve dual purposes: EO detection for electric field sensing and PPG detection for physiological parameter measurement, thereby improving detection accuracy without proportionally increasing device complexity
Solution Approach 2:
The light sensor performs multiple functions: it detects light communication signals modulated by the human electric field (EO detection) and simultaneously detects reflected light signals from the human body (PPG detection). This multi-functionality enables the device to achieve high detection accuracy for multiple parameters while maintaining a relatively simple structure
2Measurement precision
If multiple detection functions are integrated to improve detection accuracy, then detection accuracy improves, but circuit complexity increases
Solution Approach 1:
The light sensor is designed to perform both EO detection and PPG detection functions. By using the same hardware component for multiple detection purposes, the patent avoids the need for separate detection circuits, thereby maintaining circuit simplicity while achieving high detection accuracy for multiple parameters
Solution Approach 2:
The light communication signal serves dual purposes: it carries information about the human electric field (used for EO detection) and simultaneously acts as the incident light signal for PPG detection. This self-service approach eliminates the need for separate light sources and detection circuits, reducing overall circuit complexity
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
Improves detection accuracy and reduces circuit complexity, enabling precise collection of human body state information such as heart rate and respiratory rate, and physiological parameters like blood oxygen concentration.
Implementation Method 1
The light modulator includes a metal coupling structure and an EO (Electro-Optical) crystal element. The metal coupling structure receives the human electric field. The EO crystal element is attached to the metal coupling structure. The refractive index of the EO crystal element is variable according to the human electric field.
Implementation Method 2
The light waveguide is configured to transmit the light communication signal. The light waveguide is a Fabry-Perot waveguide.
Implementation Method 3
The light sensor receives the light communication signal from the light waveguide.
Implementation Method 4
The light source is an LED (Light-Emitting Diode) or a laser diode. The light source further transmits an incident light signal to a human body.
Data Source
AI summary
A wearable device includes a light modulator, a light source, a light waveguide, a light sensor, a processor, and a carrier element. The light modulator receives a human electric field. The light source generates a light communication signal. The light waveguide is adjacent to the light modulator. The light waveguide is configured to transmit the light communication signal. The light sensor receives the light communication signal from the light waveguide. The processor is coupled to the light sensor. The light modulator, the light source, the light waveguide, the light sensor, and the processor are disposed on the carrier element. The processor can obtain the relative information of the human electric field according to the phase change in the light communication signal.