Prevention of secondary brain injuries following head trauma can be accomplished most easily when intracranial pressure (ICP) is monitored. However, current measurement techniques are invasive and thus not practical in the combat environment. The Pulsed Phase Lock Loop device, which was developed and patented by consultants Drs. Yost and Cantrell, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in ICP. Year two studies included whole body head-up and head-down tilting effects on intracranial compliance and pressure in six healthy volunteers.Hargens, Alan R.Ames Research CenterPRESSURE MEASUREMENT; BRAIN DAMAGE; INTRACRANIAL PRESSURE; ULTRASONICS; VOLUME; PULSE RATE; CRANIUM; MODELS; INFECTIOUS DISEASES; COMPUTER PROGRAMS...