Method for evaluating contact pressure between an optical sensor and a user's skin and associated device
By comparing optical signals at different wavelengths to evaluate contact pressure, the method improves the accuracy of wearable devices' physiological measurements by adjusting the sensor's fit, addressing issues of poor positioning and excessive pressure.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- WITHINGS SAS
- Filing Date
- 2022-04-25
- Publication Date
- 2026-05-22
AI Technical Summary
Existing wearable devices with optical sensors, such as smartwatches, face challenges in accurately measuring blood circulation due to improper positioning, which leads to poor-quality PPG measurements, often caused by excessive contact pressure that displaces blood from superficial vessels, affecting the quality of optical signals.
A method and device that utilize optical signals at different wavelengths to evaluate contact pressure by comparing optical data obtained from green and red or green and infrared ranges, calculating a vascular parameter, and adjusting the sensor's position based on this evaluation to ensure optimal contact pressure.
The method enhances the robustness of optical signal quality by normalizing variations in contact pressure, reducing the influence of external factors, and providing user notifications to adjust the device's fit, thereby improving the accuracy of physiological measurements like heart rate and blood oxygen saturation.
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