A non-invasive detection of respiration by using ultra wideband signals

Recent research on extracting biological information by radio waves has attracted much attention for application in disaster areas or medical scenes. This technology enables the collection of biological information even from people not wearing any sensors such as RFID (Radio Frequency IDentification) tags. The purpose of this paper is to detect respiration non-invasively regardless of a person´s shape using ultra wideband signals, which are less harmful to the body or medical equipment. The respiratory detection experiment involves the analysis of reflected waves from the target body using two double-ridged guide horn antennas. The received power in the measurement system varies with time as a function of respiration. By measuring the periodicity, the possibility of non-invasive detection of respiration was demonstrated.