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