Abstract: This disclosure provides transabdominal fetal oximetry (TFO) that uses frequency-modulated continuous-wave (FMCW) time-domain near-infrared spectroscopy to measure time-resolved reflectance values of light signals collected from a maternal-fetal multilayer tissue structure. In various embodiments, the disclosed FMCW time-domain near-infrared spectroscopy is configured to function as an optical interferometer that uses two frequency-swept laser sources of different center wavelengths ?1 and ?2 as probe lights to detect optical property in vascular tissues of the maternal-fetal multilayer tissue structure. The FMCW near-infrared spectroscopy is configured to collect light signals returned from the multilayer structure and generate a time-resolved reflectance curve based on the collected light signals.

Abstract: This disclosure provides a fetal-blood-oxygen-saturation estimation technique using a deep neural network without performing explicit fetal signal extraction from mixed maternal-fetal photoplethysmogram (PPG) signals. In one aspect, the disclosed fetal-blood-oxygen-saturation estimation technique receives multiple channels of PPG signals from two or more photodetectors detecting transabdominal diffused light from two or more light sources emitting two or more distinct wavelengths, wherein the photodetectors and light sources are positioned on a maternal abdomen. Note that each channel of the multiple channels of PPG signals includes mixed maternal-fetal PPG signals.

Abstract: The system determines a fetal blood oxygenation level by 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. The system then receives a maternal signal from a first photodetector, which is positioned on the maternal abdomen to receive reflected light that traverses maternal tissue. The system also receives a mixed signal from a second photodetector, which is positioned on the maternal abdomen to receive reflected light that traverses both maternal and fetal tissue. The system performs a filtering operation that removes maternal signal components from the mixed signal to produce a fetal signal. The system determines the fetal blood oxygenation level by performing a pulse-oximetry computation on the fetal signal. The system dynamically adjusts operational parameters in the face of changing variables, such as fetus position and depth.

Abstract: The system determines a fetal blood oxygenation level by 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. The system then receives a maternal signal from a first photodetector, which is positioned on the maternal abdomen to receive reflected light that traverses maternal tissue. The system also receives a mixed signal from a second photodetector, which is positioned on the maternal abdomen to receive reflected light that traverses both maternal and fetal tissue. The system performs a filtering operation that removes maternal signal components from the mixed signal to produce a fetal signal. The system determines the fetal blood oxygenation level by performing a pulse-oximetry computation on the fetal signal. The system dynamically adjusts operational parameters in the face of changing variables, such as fetus position and depth.

Abstract: The disclosed system determines a fetal blood oxygenation level. During operation, the system activates two or more light sources, having different wavelengths, which are positioned on the abdomen of a pregnant mammal to direct light into the maternal abdomen toward a fetus. Next, the system receives a set of mixed signals from a set of photodetectors, which are positioned at different locations on the maternal abdomen to receive reflected light that traverses both maternal and fetal tissue. The system then performs a filtering operation that removes signal components associated with a maternal heart rate and a maternal respiration rate from the set of mixed signals to produce a set of fetal signals. Next, the system combines the set of fetal signals to produce a composite fetal signal. Finally, the system determines the fetal blood oxygenation level by performing a pulse-oximetry computation based on the composite fetal signal.

Abstract: Here discloses a system for sensing bladder volume. The system includes at least one patch, a plurality of light emitters, a plurality of light sensors, and a process. The at least one patch is configured to attach to a human skin or a wearable garment at locations in proximity to an abdomen area. The light emitters are directed towards the abdomen area. The light sensors are configured to receive light signals that are emitted by the light emitters, reflected by human tissues, and transmitted through an abdominal wall. At least one of the light emitters or at least one of the light sensors is disposed on the at least one patch. The processor is configured to receive information of the received light signals and to predict a bladder volume based on the information of the received light signals.