Stabilized Sensor Modules with Segmented Stabilizing Members
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Solution Overview
Problem
Conventional photoplethysmography devices face challenges in maintaining consistent skin contact during physical activity, leading to reduced signal quality due to motion artifacts and discomfort, especially in earbud form factors which struggle with optical coupling and retention.
Innovation Solution
A sensor module with a housing and guide layer featuring protrusions and stabilizing members that secure the energy emitter and detector close to the skin, using a combination of optical guides and resilient materials to maintain contact and stability during movement, and can be integrated into wearable articles like earbuds or bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional spring mechanisms are used to secure the sensor to the skin, then retention during motion is improved, but comfort deteriorates due to excessive pressure and discomfort
Solution Approach 1:
The sensor assembly is divided into multiple stabilizing members (first stabilizing member, second stabilizing member, etc.) that are distributed around the sensor. This segmentation allows the retention force to be distributed across multiple contact points rather than concentrated at a single spring location, improving both retention reliability and comfort during motion.
2Stability of the object's composition
If the sensor mass is increased to improve stability, then stability during acceleration is improved, but the device becomes less comfortable to wear for long periods
Solution Approach 1:
The stabilizing members are made of elastomeric material with specific mechanical properties that provide localized stability and cushioning. This allows the sensor assembly to maintain stability during acceleration while the elastomeric material absorbs shocks and distributes pressure, enabling comfortable long-term wear despite the added stability features.
3Reliability
If elastomeric features are added to the earbud to improve retention during vigorous activity, then retention is improved, but optical coupling performance deteriorates
Solution Approach 1:
The guide layer acts as an intermediary component between the stabilizing members and the sensor. It provides a stable platform for the sensor while allowing the stabilizing members to perform their retention function. The guide layer ensures that the sensor maintains proper alignment and optical coupling with the skin surface even when the stabilizing members are engaged during vigorous activity.
4Measurement precision
If the sensor assembly is forcibly pressed against the entire earbud to minimize motion, then motion artifacts are reduced, but user comfort deteriorates significantly
Solution Approach 1:
Instead of using a single spring to press the entire earbud against the skin, the invention segments the stabilization function into multiple stabilizing members positioned around the sensor assembly. This segmentation allows for localized stabilization at the sensor-skin interface without requiring excessive force across the entire earbud, thereby maintaining signal quality while improving user comfort.
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 provides comfortable and accurate biometric data collection by maintaining consistent skin contact and reducing motion artifacts, ensuring reliable data reporting even under extreme accelerations.
Implementation Method 1
The cover includes at least one light guide configured to guide light from the at least one optical emitter to the ear of a subject and/or guide light from the subject's body to the at least one optical detector
Implementation Method 2
The stabilizing members are configured to contact a subject's skin to stabilize the sensor module relative to the skin
Data Source
AI summary
A sensor module includes a housing and a sensor assembly disposed within the housing. The sensor assembly includes a base having at least one energy emitter and at least one energy detector, and a guide layer overlying the base in face-to-face relationship. The guide layer has at least one protrusion extending outwardly to accommodate the at least one energy emitter, and a plurality of outwardly extending stabilizing members. The housing has at least one first opening through which the at least one protrusion extends, and a plurality of second openings through which the stabilizing members extend. Some of the stabilizing members have an outwardly extending length that is greater than an outwardly extending length of the at least one protrusion. Some of the stabilizing members are substantially cylindrical and have a circular cross-sectional profile, and some of the stabilizing members are partially cylindrical and have a partially circular cross-sectional profile.