Abstract: A method and apparatus for detecting position and movement of a subject within a volume of space is described. The apparatus may comprise an upper frame having a first plurality of infrared transmitters configured to emit infrared light through the volume; and a lower frame positioned below the upper frame, having a plurality of receivers configured to detect the infrared light emitted through the volume. The apparatus is configured to fire the transmitters and activate the receivers and the apparatus is configured to report a status of successful infrared light transmission or a status of unsuccessful infrared light transmission for a particular transmitter-receiver pair after one of the first plurality of transmitters is fired.