ApneaDx™ is a new PM that uses a microphone to record breath sounds and an acoustical analysis algorithm of breath sounds to determine the (Apnea Hypopnea Index) AHI. Results from preliminary studies suggest that the AHI derived from ApneaDx™ approximates that from PSG. In preliminary studies, it appears that for the diagnosis of sleep apnea, home sleep study with ApneaDx™ is simple and reliable even when conducted by untrained users.