US 12,453,481 B2
Method and apparatus for deriving biometric information using multiple-axis seismocardiography
Yannick D'Mello, Mississauga (CA); Philip J.r. Roche, Montreal (CA); and Michel A. Lortie, Saint-Lazare (CA)
Assigned to MACDONALD, DETTWILER AND ASSOCIATES INC., Toronto (CA)
Appl. No. 17/269,777
Filed by MACDONALD, DETTWILER AND ASSOCIATES INC., Toronto (CA)
PCT Filed Aug. 20, 2018, PCT No. PCT/CA2018/051006
§ 371(c)(1), (2) Date Feb. 19, 2021,
PCT Pub. No. WO2020/037391, PCT Pub. Date Feb. 27, 2020.
Prior Publication US 2021/0315463 A1, Oct. 14, 2021
Int. Cl. A61B 5/0205 (2006.01); A61B 5/00 (2006.01); A61B 5/024 (2006.01); A61B 5/08 (2006.01); A61B 5/091 (2006.01); A61B 5/11 (2006.01); A61B 5/113 (2006.01)
CPC A61B 5/0205 (2013.01) [A61B 5/02405 (2013.01); A61B 5/02438 (2013.01); A61B 5/0816 (2013.01); A61B 5/091 (2013.01); A61B 5/1102 (2013.01); A61B 5/113 (2013.01); A61B 5/6823 (2013.01); A61B 5/7214 (2013.01); A61B 5/7257 (2013.01); A61B 5/7278 (2013.01); A61B 2562/0219 (2013.01)] 34 Claims
OG exemplary drawing
 
1. A method of non-invasively deriving at least one biometric datum, of a living vertebrate, comprising actions, at an instrument, of:
receiving, from a sensor positioned against the vertebrate, time-domain samples of measurements, by the sensor, of vibrations within a body of the vertebrate that correspond to a seismocardiogram (SCG) signal, in at least one time-stamped stream that corresponds to at least one associated axis of measurement of at least one of linear and rotational acceleration;
organizing the samples into a plurality of windowed streams, each windowed stream having an associated time period and comprising a stream of sample groups, each group having an associated monotonously changing time stamp index and comprising samples having a time stamp that precedes a time represented by the index;
separating the plurality of windowed streams into a first set of streams corresponding to physical events of the vertebrate associated with cardiovascular activity and a second set of streams corresponding to physical events of the vertebrate associated with respiration;
extracting the at least one datum from at least one of:
a selected one of the first set of streams whose associated time period is substantially an integer multiple of a period of a cardiac cycle of the vertebrate by autocorrelating the first set of streams with a time-delayed version thereof to identify at least one characteristic peak of a cardiac cycle, corresponding to a cardiac event within the cardiac cycle, of the vertebrate, and
the second set of streams by determining a characteristic frequency of respiration of the vertebrate;
identifying consecutive peaks associated with opening of an aortic valve (AO) in successive cardiac cycles and calculating a maximum positive acceleration followed by a maximum negative acceleration; and
determining a peak associated with closing of the aortic valve (AC) in a cardiac cycle for which a peak associated with opening thereof has been identified and deriving a left ventricle ejection time (LVET) from a time difference therebetween.