Angled Sensor Modules for Headsets to Reduce Environmental Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional wearable health monitors struggle to accurately measure physiological information in daily environments due to environmental interference from sunlight, temperature changes, and motion-coupled noise, which reduces sensor accuracy and generates false measurements.
Innovation Solution
A wearable monitoring apparatus with a sensor module that includes an energy emitter, detector, filter, and processor, configured to remove time-varying environmental interference by using optical filters and light-opaque materials to prevent ambient light from reaching the detector, and employing motion/position sensors to account for motion-related interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If traditional wearable health monitors are used in daily environments, then they can continuously monitor physiological information, but environmental interference from sunlight, temperature changes, and motion-coupled noise reduces measurement accuracy
Solution Approach 1:
The sensor module is segmented into distinct functional components: light-emitting elements, light-detecting elements, light-opaque shielding structures, and motion sensors. This segmentation allows each component to be optimized independently and positioned to minimize environmental interference while maintaining continuous monitoring capability
Solution Approach 2:
Light-opaque materials are introduced as intermediary shielding structures between the ambient light environment and the light-detecting elements. These intermediaries block harmful environmental light while allowing the desired optical signals from the physiological medium to reach the detector, thereby maintaining measurement accuracy during continuous monitoring
2Measurement precision
If environmental shielding structures are added to block ambient light, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
The light-opaque shielding structures are merged with the housing or casing of the wearable device, and the light-emitting and light-detecting elements are positioned in complementary orientations. This merging integrates the shielding function into the existing device structure rather than adding separate components, thereby improving signal-to-noise ratio without proportionally increasing device complexity
Solution Approach 2:
The light-emitting and light-detecting elements are positioned at angles relative to each other (e.g., 45-degree angles) rather than in simple linear arrangements. This angular positioning in multiple dimensions creates geometric relationships that naturally reject ambient light from common directions while maintaining sensitivity to physiological signals, improving measurement precision without requiring extensive shielding structures
3Measurement precision
If motion sensors are added to compensate for motion-related interference, then physiological measurement accuracy improves, but device complexity and energy consumption increase
Solution Approach 1:
The motion sensors serve multiple functions: they detect motion artifacts that interfere with physiological measurements, provide data for compensating these artifacts through signal processing, and can potentially track physical activity levels. This multi-functionality allows motion compensation capability to be added without proportionally increasing device complexity, as the same sensors contribute to multiple objectives
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 solution effectively reduces environmental noise, allowing for accurate monitoring of physiological conditions such as heart rate, blood pressure, and blood oxygen levels by isolating the sensor from ambient light and motion artifacts, thereby improving the reliability of health and fitness monitoring.
Implementation Method 1
an optical emitter that emits optical energy
Implementation Method 2
an optical filter that attenuates light at selected wavelengths
Implementation Method 3
an optical detector that detects an optical response signal
Data Source
AI summary
A headset includes a housing defining an audio cavity, a speaker located within the audio cavity, and first and second sensor modules within the housing in spaced-apart, angled relationship to each other. The housing includes an aperture through which sound from the speaker can pass, and the first and second sensor modules are on opposing sides of a direction from the speaker to the aperture. The first sensor module is configured to direct electromagnetic radiation at a first target region of an ear of a person wearing the headset and to detect a first energy response signal therefrom that is associated with one or more physiological metrics of the subject, and the second sensor module is configured to direct electromagnetic radiation at a second target region of the ear and to detect a second energy response signal therefrom that is associated with the one or more physiological metrics.