Determining respiration rate from a video of a subject breathing

A system for determining a respiration rate from a video of a subject while breathing, the system comprising:

• a storage device;
• and
• a processor executing machine readable instructions for performing:
• receiving T time-sequential image frames of a video of a subject breathing, the video being captured of an area of the subject where a signal corresponding to respiratory function can be registered by at least one imaging channel of an imaging device used to capture that video, the video comprising a first portion of at least 10 seconds of video for a total of N image frames, and a second portion of M image frames, where N+M=T;
• for each image frame It, where t=1 to N, determining a flow vector Ft(x,y) for each (x,y) pixel location;
• determining a correlated flow field V which captures how the individual flow vectors in each image frame are correlated to each other;
• for each image frame It, where t=1 to M:
• determining a flow vector Ft(x,y) at each (x,y) pixel location;
• and
• determining a velocity velt for the tth image frame;
• integrating the velocities over the image frames of the second portion of the video to obtain an integrated signal corresponding to thoracoabdominal movement;
• determining a respiration rate for the subject from the integrated signal;
• and
• communicating the respiration rate to the storage device.