Apple Inc.
Force sensing for PPG heart-rate performance enhancement and contact detection

Abstract:

The present disclosure generally relates to wearable devices and methods for measuring a photoplethysmographic signal. The wearable devices and methods may include a force sensor that provides input used for motion-noise filtering to obtain improved PPG signals. Feedback from the force sensor may also be used to indicate whether the amount of pressure exerted by the device should be adjusted, or whether the device should be switched to a locked state.