SLEEP MONITORING SYSTEM AND METHOD Russian patent published in 2019 - IPC A61B5/11 

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment. System for monitoring a subject in bed comprises a camera for capturing images of the subject in bed, motion vector estimation means for determining motion vectors depending on the location in each successive image from the set of images obtained in the time interval, and a signal processing system. Signal processing system is arranged to determine in each successive image a map of locations in the image for blocks in each corresponding image related to the body area of the subject in the bed, and the direction of the main axis of the body area in the bed according to the determined map of locations in the image. Direction is determined by the size of the body area in the bed in the direction of the main axis, which is larger or not smaller than the size of the body area in the bed in all other directions. Direction of the main axis of the body area in the bed is adaptable in response to deviations of the main axis from the longitudinal direction of the bed. Signal processing system is also configured to calculate the index of the subject's rotational movement in the bed, which comprises using the direction of the main axis of the body area in the bed and components of certain motion vectors of each block in each corresponding image that are normal with respect to the direction of the main axis of the body area in the bed, and subsequently summing said components into blocks from the corresponding map of the locations of the images associated with the body area of the subject in the bed, within each successive image from the set of images. Signal processing system is adapted to detect changes in the subject’s posture in the bed based on the calculated indicator of the subject’s rotational movement.

EFFECT: more reliable determination of the state of sleep.

12 cl, 6 dwg