An elastically flexible pressing contact of transmitter and receiver on {HEAD ~ the skin surface} can be provided by {TAIL ~ the air cushion} formed with the aid of the two walls 
An elastically flexible pressing contact of transmitter and receiver on { HEAD ~ the skin surface } can be provided by { TAIL ~ the air cushion } formed with the aid of the two walls
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH