US 12,290,346 B2
Motion artifact removal by time domain projection
Ian R. Shapiro, Saratoga, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Aug. 3, 2020, as Appl. No. 16/983,700.
Application 16/983,700 is a continuation of application No. 14/454,562, filed on Aug. 7, 2014, granted, now 10,758,133.
Prior Publication US 2020/0359919 A1, Nov. 19, 2020
This patent is subject to a terminal disclaimer.
Int. Cl. A61B 5/024 (2006.01); A61B 5/00 (2006.01); A61B 5/026 (2006.01)
CPC A61B 5/02416 (2013.01) [A61B 5/721 (2013.01); A61B 5/02405 (2013.01); A61B 5/0261 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A device for determining a heart rate of a user, comprising:
a light emitter operative to emit light towards a skin of the user when the device is worn by the user;
a light detector operative to receive a portion of the emitted light that has interacted with the skin of the user and generate a light signal corresponding to the received portion of the emitted light;
an accelerometer operative to generate an acceleration signal corresponding to a movement of the user, wherein the acceleration signal comprises a signal stream of acceleration measurements; and
a processor operative to:
receive the light signal and the acceleration signal;
generate an integrated acceleration signal from the acceleration signal;
identify, using a least squares algorithm, a best representation of the acceleration signal and the integrated acceleration signal in the light signal;
remove the identified best representation of the acceleration signal and the integrated acceleration signal from the light signal to generate a filtered signal; and
determine the heart rate of the user using the filtered signal.