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