Non-Invasive Detection of Increased Intracranial Pressure Using Acoustical Techniques
Final rept. 8 Aug 1992-7 Feb 1994
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This study was undertaken to determine the relationships between intracranial pressure ICP and the acoustic response of the head. Potentially fatal increases in ICP can occur in soldiers afflicted with Acute Mountain Sickness at high-altitude, yet there is no reliable and noninvasive procedure to monitor ICP changes in uncontrolled conditions. In this investigation, an ovine animal model was used in which incremental increases in ICP were elicited and directly measured through intraventricular cannulae. At each ICP increment, a vibration source elicited a flexural response of the animals head, and this acoustic response was measured at four locations on the skull using accelerometers. Spectral analysis of the response showed numerous changes in proportion to ICP up to roughly 20 CmH2O above normal a clinically significant range. For example, changes in magnitude and phase at frequencies between 4 and 7 kHz each correlated well 0.92 with ICP across the study group. Thus, alterations in ICP give rise to measurable acoustic changes that can potentially be used to noninvasively monitor afflicted soldiers in uncontrolled environments. Altitude, Cerebral edema, Acoustics, Mountain sickness, RAD III.
- Medicine and Medical Research
- Stress Physiology