US 11,937,904 B2
Detecting the end of cardio machine activities on a wearable device
James P. Ochs, San Francisco, CA (US); Mariah W. Whitmore, Cupertino, CA (US); Mark P. Sena, Larkspur, CA (US); Julia K. Nichols, Alameda, CA (US); Erin Paeng, Portland, OR (US); Vinay R. Majjigi, Mountain View, CA (US); Karthik Jayaraman Raghuram, Mountain View, CA (US); and Hung A. Pham, Oakland, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Sep. 9, 2020, as Appl. No. 17/016,020.
Claims priority of provisional application 62/897,722, filed on Sep. 9, 2019.
Prior Publication US 2021/0068689 A1, Mar. 11, 2021
Int. Cl. A61B 5/24 (2021.01); A61B 5/00 (2006.01); A61B 5/024 (2006.01); A61B 5/11 (2006.01)
CPC A61B 5/02438 (2013.01) [A61B 5/02416 (2013.01); A61B 5/1118 (2013.01); A61B 5/6813 (2013.01); A61B 2562/0223 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for improving performance of a wearable device while recording a cardio-machine activity, the method comprising:
starting a recording of the cardio machine activity on the wearable device;
measuring, by a motion sensing module of the wearable device, motion data of a user of the wearable device;
measuring, by a heart rate sensing module of the wearable device, heart rate data of the user, the heart rate sensing module comprising a photoplethysmogram (PPG) sensor configured to be worn adjacent to the user's skin;
detecting, by a processor circuit, an end of the cardio-machine activity by:
determining rotational data from the motion data, the rotational data describing a position of the wearable device in a three-dimensional space relative to a frame of reference;
estimating a device heading based on the rotational data;
tracking the heading of the wearable device at multiple time points during the cardio machine activity to estimate a relative heading;
detecting a variable heading by determining that the relative heading exceeds a heading threshold;
detecting the end of the cardio machine activity in response to detecting the variable heading; and
confirming the end of the cardio-machine activity based on at least one of the heart rate data and the motion data; and
in response to the confirming the end of the cardio-machine activity, ending, by the processor circuit, the recording of cardio machine activity.