What does a single axis accelerometer measure?
D000328:Adult; D001450:Ballistocardiography / Q000295:instrumentation; D001783:Blood Flow Velocity; D002302:Cardiac Output; D006801:Humans; D007702:Kinetocardiography / Q000295:instrumentation*; D008297:Male; D009200:Myocardial Contraction; D011187:Posture; D013977:Tibia