Noninvasive Intracranial Volume and Pressure Measurements Using Ultrasound.
Abstract
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 (PPLL) device, which was developed and patented by consultants Dr. Yost and Dr. Cantrell, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in lOP. Year one studies involved instrument improvements and measurement of altered intracranial distance with altered ICP in fresh cadavera. We accomplished our goals for the past year. Our software was improved to facilitate future studies of normal subjects and trauma patients. Our bench studies proved that PPLL output correlated highly with changes in path length across a model cranium. Cadaveric studies demonstrated excellent correlation between invasive and noninvasive measures of ICP using an input arterial pulse. A compact, noninvasive device for monitoring changes in intracranial distance may aid in the early detection of elevated lCP, decreasing risk of secondary brain injury and infection, and returning head-injured patients to duty.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1998
- Accession Number
- ADA339344
Entities
People
- Alan R. Hargens
Organizations
- National Aeronautics and Space Administration