It uses a radar beam of 15 to 20 degrees and a specialized signal processor to discern respiration from up to three meters away, with no physical connection between subject and radar. Its signal penetrates clothing, and the flashlight requires a body movement of only a few millimeters to detect human presence. A provisional patent application for the device has been filed. The signal processor is outside the flashlight-sized casing, and the respiration signature is displayed on a monitor.
Plans are to make all the equipment small enough to fit inside the flashlight housing.
Read a news release on this topic. Read a paper on this topic.