We have developed a non-contact microwave radar respirometry method, where the microwave radars are located under the bed, they do not increase the strain on the subjects. In order to evaluate the effectiveness of the microwave radar respirometry, we have conducted clinical tests to make a comparison between the proposed non-contact method and polysomnograph (PSG). We tested the proposed system on twenty subjects suspected to have Sleep Apnea Syndrome (SAS) (male 16, female 4, age 35 to 67, average 49.8±10.1 years old). PSG was adopted as a reference to determine Apnea Hypopnea events. The proposed method detected 75.6% of Apnea Hypopnea events, (2,810 out of 3,716 events), and it was 58.8% of total radar events (2,810 out of 4,780 radar events.).
