Cerebral Blood Flow Based Computer Modeling of G_z-Induced Effects

Area of Science:

• Aerospace Medicine
• Human Factors Engineering
• Physiological Modeling

Background:

• Acceleration (G) effects are critical in aviation accidents, impacting consciousness and vision.
• G-induced loss of consciousness (G-LOC) and related phenomena pose risks in military, aerobatic, and agricultural aviation.
• Understanding G-effects is vital for flight safety and accident investigation.

Purpose of the Study:

• To develop and validate a software model for evaluating G-LOC risk in aeronauts.
• To assess the impact of various physiological and equipment factors on G-tolerance.
• To provide a tool for understanding risk changes due to fatigue, medications, and countermeasures.

Main Methods:

• Developed the Civil Aerospace Medical Institute G-Effects Model (CGEM) using physical and physiological variables.
• Modeled aeronauts with parameters including sex, fitness, G-suits, and breathing gear.
• Validated the CGEM against experimental data from peer-reviewed literature and centrifuge studies.

Main Results:

• CGEM accurately predicted physiological Gz exposure effects, especially for rapid onset rates.
• Predicted G-LOC times and incapacitation periods were within 1 SD of experimental results from USN and USAF pilots.
• Model predictions for visual effects onset and aerobatic maneuver symptoms aligned with published data.

Conclusions:

• CGEM is a valuable new tool for civil and military aviation safety.
• The model offers insights into risk changes from factors like fatigue, medications, and anti-G countermeasures.
• Flight surgeons, pilots, and investigators can utilize CGEM for better risk assessment beyond simple G-tolerance values.