Button-Integrated Optical Sensor for Finger Biometric Capture
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Solution Overview
Problem
Current optical sensors in electronic devices struggle to capture physiological data from a user's finger or fingertip, require multiple cameras for data capture, and do not utilize red and infrared wavelengths to measure blood oxygenation levels effectively.
Innovation Solution
An optical sensor is integrated into a button of an electronic device, utilizing a substrate with emitters and detectors, including LEDs for different wavelengths, and a baffle to limit crosstalk, allowing for accurate physiological data capture from a finger or fingertip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical sensors are disposed in components that contact the user (such as watch areas, bands, or finger clips), then physiological data can be captured, but the device complexity increases and requires additional components
Solution Approach 1:
The optical sensor is merged with the button structure, combining two separate functions (button operation and physiological sensing) into a single integrated component. This eliminates the need for separate sensing components while maintaining measurement capability.
Solution Approach 2:
The button is designed to serve multiple functions: mechanical input operation and optical sensing for physiological data capture. This multi-functionality reduces the overall component count and device complexity while achieving the measurement objective.
2Measurement precision
If multiple cameras are used to capture physiological data, then data capture capability is improved, but the device complexity and computational requirements increase
Solution Approach 1:
Multiple camera functions are merged into a single optical sensor module with integrated emitters and detectors. This consolidation achieves the same physiological data capture capability as multiple cameras while reducing component count and complexity.
Solution Approach 2:
The optical sensor system replaces complex camera-based imaging systems with a more compact emitter-detector configuration that achieves equivalent or superior physiological measurement capability with reduced computational requirements.
3Measurement precision
If optical sensors do not utilize red and infrared wavelengths, then device complexity is reduced, but the ability to measure blood oxygenation levels is impaired
Solution Approach 1:
Different wavelengths (red and infrared) are applied at specific locations within the optical sensor to target specific measurement objectives. The red LED measures one parameter while the infrared LED measures another, with each wavelength optimized for its specific function.
Solution Approach 2:
The optical sensor utilizes multiple wavelengths (red and infrared) to change the measurement parameters, enabling differentiation between various physiological metrics including blood oxygenation levels. This multi-parameter approach enhances measurement precision without proportionally increasing complexity.
4Measurement precision
If the substrate has equal length and width dimensions, then manufacturing is simplified, but the optical sensor cannot effectively separate emitters and detectors to reduce crosstalk
Solution Approach 1:
The substrate is designed with asymmetric dimensions (length greater than width) to optimize the spatial arrangement of emitters and detectors. This asymmetric geometry enables effective separation of optical paths while maintaining manufacturability through standard fabrication processes.
Solution Approach 2:
The optical sensor utilizes the length dimension of the substrate to separate emitters and detectors along the longitudinal axis, creating sufficient optical path separation to minimize crosstalk. This dimensional approach to separation is more effective than attempting separation in a square configuration.
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 enables convenient and frequent access to physiological data capture, improves measurement accuracy, reduces computational costs, and eliminates the need for additional devices like fitness trackers.
Implementation Method 1
The one or more emitters include a first light emitting diode (LED) configured to emit red light and a second LED configured to emit green light. Furthermore, in some implementations, the one or more emitters can include a third LED configured to emit infrared light.
Implementation Method 2
The optical sensor includes one or more detectors positioned closer to the second end of the substrate. The optical sensor is configured to obtain biometric data for determining one or more biometrics of a user.
Data Source
AI summary
A computing device includes a housing defining an aperture extending therethrough. The computing device further includes a button that includes a switch and a body. The body is at least partially disposed within the aperture and movable relative to the housing between a first position and a second position to selectively actuate the switch to cause the computing device to perform a function. The button includes a printed circuit electrically coupled to one or more processors of the computing device. The button includes an optical sensor disposed within the interior of the body and configured to obtain biometric data for determining one or more biometrics of a user.