US 12,070,312 B2
Contextually aware fetal sensing in transabdominal fetal pulse oximetry
Soheil Ghiasi, Davis, CA (US); and Daniel Fong, Davis, CA (US)
Assigned to The Regents of the University of California, Oakland, CA (US)
Filed by The Regents of the University of California, Oakland, CA (US)
Filed on Mar. 16, 2020, as Appl. No. 16/820,388.
Application 16/820,388 is a continuation in part of application No. 16/347,532, granted, now 11,116,412, previously published as PCT/US2017/062782, filed on Nov. 21, 2017.
Claims priority of provisional application 62/424,789, filed on Nov. 21, 2016.
Prior Publication US 2020/0214603 A1, Jul. 9, 2020
Int. Cl. A61B 5/1464 (2006.01); A61B 5/00 (2006.01); A61B 5/0205 (2006.01); A61B 5/024 (2006.01); A61B 5/08 (2006.01); A61B 5/1455 (2006.01)
CPC A61B 5/1464 (2013.01) [A61B 5/0205 (2013.01); A61B 5/14552 (2013.01); A61B 5/7214 (2013.01); A61B 5/725 (2013.01); A61B 5/7257 (2013.01); A61B 5/7278 (2013.01); A61B 5/02411 (2013.01); A61B 5/0816 (2013.01); A61B 5/4356 (2013.01); A61B 2562/0238 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A method for determining a fetal blood oxygenation level, comprising:
activating two or more light sources, having different wavelengths, which are positioned on the maternal abdomen of a pregnant mammal to direct light into a maternal abdomen toward a fetus;
receiving a set of mixed signals from a set of photodetectors, which are positioned at different locations on the maternal abdomen to receive reflected light from the two or more light sources that traverses both maternal and fetal tissue;
measuring a maternal heart rate through an external maternal heart rate sensor;
measuring a maternal respiration rate through an external maternal respiration rate sensor;
performing a filtering operation that removes signal components associated with the maternal heart rate and the maternal respiration rate from the set of mixed signals to produce a set of fetal signals;
combining the set of fetal signals to produce a composite fetal signal by computing a dynamic weighted average of the set of fetal signals based on dynamic coefficients, which are adjusted based on evolving confidence factors associated with each individual mixed signal; and
determining the fetal blood oxygenation level by performing a pulse-oximetry computation based on the composite fetal signal.