{HEAD ~ The intensity} of the reflective ultrasonic signals is used to determine {TAIL ~ the location} of a preselected body structure 
{ HEAD ~ The intensity } of the reflective ultrasonic signals is used to determine { TAIL ~ the location } of a preselected body structure
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH