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