PPG Wearable Monitoring with Adaptive Power and Signal Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional photoplethysmography (PPG) devices face challenges in maintaining consistent skin contact during physical activity, leading to reduced signal quality due to motion artifacts and high power consumption, especially in wearable forms like earbuds, which can be uncomfortable and inefficient in power management.
Innovation Solution
A monitoring device with a processor that adjusts signal analysis frequency and sensor interrogation power based on detected changes in activity, using optical sensors with adjustable algorithms and power settings to optimize data collection during varying activity levels, and environmental conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the magnitude of light energy reaching the skin is increased to improve signal quality, then measurement precision is improved, but use of energy increases
Solution Approach 1:
The patent applies dynamics by making the light energy magnitude adjustable rather than fixed. The system dynamically adapts the interrogation power based on detected activity levels, using higher power during low-activity periods when motion artifacts are minimal and lower power during high-activity periods, thereby resolving the contradiction between maintaining signal quality and reducing power consumption
Solution Approach 2:
The patent changes the parameter of light energy magnitude based on activity detection. By monitoring activity levels and adjusting the light energy parameter accordingly, the system optimizes the balance between signal quality and power consumption, using higher energy magnitudes when needed for accuracy and lower magnitudes when motion artifacts would degrade signal quality
2Measurement precision
If signal analysis frequency is increased to improve accuracy during high activity, then measurement precision is improved, but use of energy increases
Solution Approach 1:
The patent applies dynamics by making the signal analysis frequency adjustable based on activity levels. During high-activity periods when motion artifacts are prevalent, the system increases analysis frequency to capture rapid signal changes and apply more sophisticated filtering. During low-activity periods, it reduces analysis frequency to conserve power, since less frequent sampling is sufficient when motion artifacts are minimal
Solution Approach 2:
The patent changes the signal analysis frequency parameter in response to detected activity levels. This dynamic parameter adjustment allows the system to maintain high accuracy during challenging conditions while reducing power consumption during stable conditions, resolving the contradiction between precision and energy use
3Reliability
If elastomeric features are added to earbuds to improve retention during exercise, then reliability is improved, but optical skin coupling is degraded
Solution Approach 1:
The patent applies local quality by differentiating the properties of different parts of the earbud. The distal portion that contacts the skin is made substantially planar and free of elastomeric features to ensure optimal optical coupling, while other portions of the earbud may incorporate elastomeric features for retention. This localized differentiation resolves the contradiction between retention and optical coupling by assigning different functional requirements to different regions
4Reliability
If conventional spring mechanisms are used to maintain skin contact during exercise, then reliability is improved, but device mass increases
Solution Approach 1:
The patent applies the taking out principle by removing the spring mechanism entirely from the earbud design. Instead of using a mechanical spring to maintain skin contact, the system relies on the earbud's overall form factor and fit within the ear canal to maintain consistent optical coupling. This extraction of the spring component resolves the contradiction by eliminating the source of motion artifacts and reducing device mass while maintaining reliability through alternative means
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 signal quality and accuracy of physiological data collection by adapting to activity levels and environmental conditions, while reducing power consumption and enhancing comfort and usability of wearable devices.
Implementation Method 1
Photoplethysmography (PPG) is based upon shining light into the human body and measuring how the scattered light intensity changes with each pulse of blood flow
Implementation Method 2
The sensor may be an optical sensor that includes at least one optical emitter and at least one optical detector
Data Source
AI summary
A method of monitoring a subject via a photoplethysmography (PPG) sensor configured to detect and/or measure PPG information from the subject includes changing, via a processor, signal analysis frequency of the PPG sensor signals, optical wavelength emission of the PPG sensor, and/or PPG sensor interrogation power at predetermined times. Each predetermined time is associated with measuring at least one different biometric parameter from a plurality of biometric parameters.