Optical Finger Mouse Signal Separation for Physiological Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pulse oximeters cannot accurately detect physiological characteristics on portable electronic devices due to signal noise caused by movement and interference from ambient light sources, making them unsuitable for use with portable devices.
Innovation Solution
An optical finger mouse equipped with two light sources emitting different wavelengths, an image sensor, and a processing unit that uses independent component analysis to separate movement information from physiology information, eliminating noise and allowing for simultaneous detection of finger displacement, contact status, and physiological characteristics like blood oxygenation and heart rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional pulse oximeters are used to detect physiological characteristics, then blood oxygenation and heart rate can be monitored, but signal noise from movement and ambient light makes accurate detection impossible
Solution Approach 1:
The patent segments the detection process into distinct phases: capturing image frames during light source activation, capturing reference frames during light source deactivation, and separately processing movement information versus physiology information. This segmentation allows the system to isolate and eliminate ambient light interference and movement noise independently, resolving the contradiction between detecting physiological characteristics and eliminating signal noise.
Solution Approach 2:
The patent introduces reference image frames captured during light source deactivation as an intermediary to subtract ambient light interference from the main detection frames. Additionally, it uses independent component analysis as a mathematical intermediary to separate movement-induced signal variations from actual physiological signals, thereby eliminating noise while preserving measurement accuracy.
2Adaptability or versatility
If the device detects both finger displacement and physiological characteristics simultaneously, then comprehensive user information is obtained, but the system complexity increases
Solution Approach 1:
The patent makes the image sensor and processing unit universal by designing them to perform multiple functions: detecting finger contact status, measuring finger displacement, and monitoring physiological characteristics all through the same optical detection system. This multi-functionality approach increases adaptability while avoiding the need for separate detection systems, thus not increasing overall device complexity.
Solution Approach 2:
The patent merges the detection of finger displacement and physiological characteristics into a single integrated processing workflow. Both types of information are extracted from the same sequence of image frames through unified image processing and independent component analysis, simplifying the system architecture while providing comprehensive detection capabilities.
3Measurement precision
If the light source remains continuously on to ensure adequate lighting for detection, then image quality is maintained, but energy consumption increases
Solution Approach 1:
The patent implements periodic activation of the light source, switching it on and off in synchronized cycles with the image frame capture. The light source is activated only during specific intervals when reference frames or detection frames need to be captured, rather than remaining continuously on. This periodic action maintains adequate lighting quality when needed while significantly reducing overall energy consumption during idle periods.
Solution Approach 2:
The system uses the periodic light source activation itself to serve dual purposes: providing necessary illumination for image capture while simultaneously creating the temporal structure needed for ambient light subtraction. The dark frames captured during light source deactivation automatically provide the reference data needed to eliminate ambient light interference, making the system self-sufficient without requiring continuous illumination.
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
Effectively eliminates signal noise from movement and ambient light, enabling accurate detection of physiological characteristics on portable devices, providing a mechanism to regulate system frequency and enter sleep mode, while ensuring accurate calculations only when finger displacement is within predetermined limits.
Implementation Method 1
a first light source (111) emits light of a first wavelength to the finger, and a second light source (112) emits light of a second wavelength to the finger
Implementation Method 2
an image sensor (14) is configured to capture reflected light from the finger with a sampling frequency to generate a plurality of first image frames corresponding to the on-state of the first light source and a plurality of second image frames corresponding to the on-state of the second light source
Implementation Method 3
a processing unit (15) is configured to separate movement information from physiology information, and to calculate the displacement and the physiological characteristic
Data Source
AI summary
There is provided an optical finger mouse including two light sources, an image sensor and a processing unit. The two light sources emit light of different wavelengths to illuminate a finger surface. The image sensor receives reflected light from the finger surface to generate a plurality of image frames. The processing unit detects a displacement and a contact status of the finger surface and a physiological characteristic of a user according to the plurality of image frames. There is further provided an electronic device and a physiological characteristic detection device.