A Forehead-Mounted Measure of O2 Saturation: The Potential for in Cockpit Hypoxia Early Detection and Warning

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA523516&Location=U2&doc=GetTRDoc.pdf

A Forehead-Mounted Measure of O2 Saturation: The Potential for in Cockpit
Hypoxia Early Detection and Warning

Rita G. Simmons, Joseph F. Chandler & Dain S. Horning



NAMRL 10-26

Sponsoring agency USAARL

Symptoms of hypoxia have been documented among rotary-wing pilots and aircrew. An automated hypoxia warning system would be the optimal warning system, but currently no military aviation platform is outfitted with a physiological monitoring system to alert pilots and aircrew of impending hypoxic episodes. The objectives of this experiment were to compare the sensitivity of, and agreement between, a forehead-mounted pulse oximeter (Forehead) and finger-mounted pulse oximeter (Finger) for application in an early warning detection system. Military personnel donned an aviation flight mask connected to the Reduced Oxygen Breathing Device (ROBD), and were instrumented with the Forehead and Finger oximeters. Following instrumentation, subjects breathed ambient air through the ROBD, followed with one of two
counterbalanced ascent profiles used to model exposure to altitude, while data were collected from both sensors.
Results indicate an exceptionally strong agreement between the Forehead and Finger sensors. The sensitivity analyses revealed that the Forehead sensor was significantly faster when responding to rapid changes in SpO2 than the Finger. While the data may seem to suggest that the Forehead sensor is accurate and sensitive to altitude induced changes in SpO2, major
drawbacks exist for the technology utilized in the current study. Reflectance technology remains promising, but significant improvements aimed at diminishing noise, curbing motion artifact, and improving reliability are required to reduce errant measurements before it can be considered for aviation applications.