Publication Abstracts

In-Flight Cerebral Oxygen Status: Continuous Monitoring by Near-Infrared Spectroscopy

Asao Kobayashi, Ph.D. and Yoshinori Miyamoto, Ph.D.
Aviat Space Environ Med 2000; 71:177-83

Abstract

Background: Little is known about the in-flight cerebral oxygen status (COS) of fighter pilots. The purpose of this study was to evaluate the COS of fighter pilots during an F-15DJ flight. Methods: Three male F-15DJ fighter pilots volunteered to serve as test subjects during aerial gunnery training (AGT) missions. During the flight, the pilots' COS was continuously monitored from the right forehead using a NIRO-300G near-infrared spectrophotometer. This new instrument is capable of measuring the concentration changes in the brain of oxygenated hemoglobin (O₂Hb), reduced hemoglobin (HHb), total hemoglobin (cHb, O₂Hb + HHb), and the tissue oxygenation index (TOI, O₂Hb/cHb). Results: Continuous changes of COS within the brain were clearly demonstrated using NIRO-300G, the changes included reductions in O₂Hb, cHb, and TOI with increased +Gz, in a mirror image fashion. The maximum decreased concentration of hemoglobin during flight ranged from 12.8 to 25.6 µmol · L^-1 (of brain tissue). Conclusions: We believe this study is the first monitoring of COS during F-15 actual flight. The monitoring of COS during F-15 flight showed that the effect of +Gz was to simultaneously lower blood flow in a mirror image fashion. Our results demonstrated that near-infrared spectroscopy (NIRO-300G) provides a reliable and sensitive method for the monitoring of pilots' COS during flight.

Keywords: acceleration, near-infrared spectrophotometry, hemoglobin, physiologic monitoring, aviators, high-performance aircraft.

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Table of Contents for Volume 71, Number 2 of the ASME journal.