Abstract: In one embodiment, a method includes recording, by a camera of a client device, a video of a region of a first user's skin and estimating, from the recorded video, a current ratio of ratios (RoR) for the first user corresponding to the first user's current blood-oxygen saturation. The method further includes converting the first user's determined RoR to a transformed RoR for the first user based at least in part on a baseline user's RoR determined while generating a trained SpO2 prediction model. The trained SpO2 prediction model is trained to estimate the baseline user's SpO2 value based on an input RoR value from the baseline user. The method further includes determining, by the trained SpO2 prediction model and based on the transformed RoR for the first user, the first user's current estimated blood-oxygen saturation.

Abstract: A method performed by at least one processor includes obtaining an image of a subject; preprocessing the image of the subject; inputting the preprocessed image into a machine learning model trained in accordance with a first frequency distribution corresponding to a first ground truth obtained from one or more sensors performing a vital measurement on one or more test subjects; and obtaining, from the machine learning model, an estimate of a signal corresponding to the vital measurement of the subject.

Abstract: In one embodiment, a method includes accessing a video of a user's face. The method further includes accessing, for each image frame in the video, (1) one or more facial landmarks determined by a facial landmark detection (FLD) model and (2) a corresponding determined position in the image for each facial landmark. The method further includes determining, based on the one or more facial landmarks and corresponding positions, a motion of the user's face in the captured video; extracting, from the determined motion of the user's face, a corrected motion signal of the user's face; adjusting, based on the extracted corrected motion signal of the user's face, the positions of one or more facial landmarks in the image frames; and determining, based at least in part on the adjusted positions of the facial landmarks in the sequential images of the video, one or more vital signs of the user.

Abstract: A method includes capturing a video of a person's face using a camera. The method also includes determining a motion-based respiratory rate (RR) and a motion-based respiratory signal based on the video of the person's face. The method further includes determining a remote photoplethysmography (rPPG)-based RR and an rPPG-based respiratory signal based on the video of the person's face. The method also includes predicting whether the motion-based RR or the rPPG-based RR is more likely to be accurate using a trained machine learning model that receives the motion-based respiratory signal and the rPPG-based respiratory signal as input. In addition, the method includes presenting one of the motion-based RR or the rPPG-based RR based on the prediction.

Abstract: In one embodiment, a method includes accessing a sequence of images of a portion of a person's skin illuminated by ambient light and determining, from at least one of the images, a plurality of microregions in the portion of the person's skin. The method further includes determining, based on a similarity between particular microregions of the plurality of microregions, one or more regions of interest of the person's skin; determining, for each of the regions of interest, a remote photoplethysmogram (rPPG) signal based on the sequence of images; and determining, based on one or more of the rPPG signals, an estimate of an oxygen saturation in the person's blood.

Abstract: In one embodiment, a method includes accessing a plurality of images of a region of interest of a person's skin and extracting, from the plurality of images, a color signal of the region of interest as a function of time. The method further includes determining, based at least on the color signal, a first quality associated with an estimated vital sign of the person, where the vital sign estimate is determined from the plurality of images.

Abstract: A multimodal, contactless vital sign monitoring system is configured to perform the following operations. Images are received from a video capture device. An image of a subject is identified within the images. The image of the subject is segmented into a plurality of segments. A first analysis is performed on the plurality of segments to identify a color feature. A second analysis is performed of the plurality of segments to identify a motion feature. Using a combination of the color feature and the motion feature a plurality of vital signs for the subject are determined. The first analyzing and the second analyzing are performed in parallel. The plurality of vital signs include one or more of heart rate, respiration rate, oxygen saturation, heart rate variability, and atrial fibrillation.