Physiological Detection Device Reducing Motion Artifacts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wearable devices struggle to accurately detect physiological signals due to motion artifacts, which are not effectively eliminated by existing methods using accelerometers or Gyros, especially under continuous motion or low temperatures.
Innovation Solution
A physiological detection device employing multiple light sources of different wavelengths, such as infrared and green light, and multiple light sensors to directly reduce motion artifacts in the analog stage, without the need for additional motion sensors like accelerometers or Gyros, by adjusting the emission intensity based on intensity differences and variations detected by the sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an accelerometer or Gyro is added to eliminate motion artifacts, then motion artifact removal capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical motion sensing system (accelerometer/Gyro) with an optical detection system using multiple light sources and light sensors. The optical system directly detects motion artifacts through changes in light absorption and reflection patterns, eliminating the need for separate mechanical motion sensors while maintaining motion artifact removal capability.
Solution Approach 2:
The optical detection system performs dual functions: it simultaneously measures physiological signals (heart rate, oxygen saturation) and detects motion artifacts. By using multiple wavelengths of light, the system can distinguish between physiological signal changes and motion-induced changes, making the same optical components serve multiple purposes without requiring additional dedicated motion sensors.
2Measurement precision
If an accelerometer or Gyro is added to eliminate motion artifacts, then motion artifact removal capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive mechanical motion sensors (accelerometer/Gyro) with optical detection components that are already necessary for physiological signal measurement. This substitution eliminates the need for additional expensive components while achieving motion artifact removal, thereby reducing overall manufacturing cost.
Solution Approach 2:
The system uses the same optical components (light sources and light sensors) for both physiological signal detection and motion artifact detection. This multi-functionality eliminates the need for separate motion sensing components, reducing bill of materials cost and simplifying the manufacturing process.
3Measurement precision
If multiple light sources and light sensors are used to reduce motion artifacts, then motion artifact reduction is improved, but device complexity increases
Solution Approach 1:
The patent divides the optical detection system into multiple independent channels, each using a specific wavelength of light. By segmenting the detection into different wavelength channels (e.g., red, infrared, green), the system can independently analyze motion artifacts affecting each wavelength differently, then combine the information to eliminate motion artifacts while maintaining physiological signal accuracy.
Solution Approach 2:
The system changes the wavelength parameter of light sources to create multiple detection channels. By using light sources with different wavelengths that interact differently with tissue and motion, the system can distinguish motion artifacts from physiological signals. The processor analyzes intensity variations across different wavelengths to identify and remove motion-induced changes.
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
This approach effectively reduces motion artifacts, improving the accuracy of physiological signal detection and eliminating the need for additional motion sensors, thereby simplifying the system and reducing costs while maintaining high detection precision.
Implementation Method 1
The physiological signal, e.g., including photoplethysmography (PPG) and oxygen saturation SPO2, detected by an optical device
Implementation Method 2
The first light sensor is configured to receive a first intensity light associated with the first light source and a second intensity light associated with the second light source from the skin surface
Data Source
AI summary
There is provided a physiological detection device for detecting physiological signals via a skin surface and including a first light source, a second light source, a first light sensor, a second light sensor and a processor. The first light source emits light via an optical element that causes the first light sensor and the second light sensor to receive different percentages of light energy of the first light source. The first light sensor and the second light sensor receive the same percentage of light energy of the second light source. The processor adjusts emission intensity of the first light source according to an intensity difference between two light energies received by the first and second light sensors as well as an intensity variation of light energy received by the first light sensor to alleviate motion artifacts in the physiological signals.