Patent attributes
The sleep monitoring system uses a motion vector estimator to determine motion vectors as a function of location in camera images. A signal processing system with an input coupled to the motion vector estimator computes a measure of turning motion, by summing motion vectors from respective locations within an image. Pose changes are detected based on the measure of turning motion. The measure of turning motion may be computed from a sum of components of the motion vectors that are normal to the major axis of a body area in the image, which is determined based on image content changes in a set of images from the camera. To avoid false turning detection due to leg kicking or similar motion the detected turning motion may be reduced to zero if it is not detected in a sufficiently large part of the body area.