Frequency analysis of heart rate variability under flight conditions

Area of Science:

• Human physiology
• Aerospace medicine
• Biomedical engineering

Background:

• Heart rate variability (HRV) is a physiological indicator reflecting autonomic nervous system activity.
• Understanding HRV responses to workload is crucial for optimizing human performance and safety, especially in demanding environments like aviation.

Purpose of the Study:

• To investigate the factors influencing heart rate variability (HRV) under various physical and mental workloads, including specific flight conditions.
• To analyze the frequency domain characteristics of HRV in relation to different operational demands.

Main Methods:

• Frequency analysis of heart rate was performed using a fast Fourier analyzer.
• Cross-correlation analysis was conducted between heart rate, blood pressure, and respiration.
• HRV frequency components were examined at rest, during physical exertion, and under varying mental loads.

Main Results:

• At rest, HRV main frequencies were observed at 0.1 Hz and 0.25-0.3 Hz.
• Physical loads caused these HRV fluctuations to disappear.
• Moderate mental load initially increased the 0.1 Hz frequency, which then decreased with increasing mental load.

Conclusions:

• The 0.1 Hz frequency component of HRV appears influenced by higher brain centers during mental workload.
• During flight, HRV frequencies decreased during takeoff and landing but remained stable during gunnery and acrobatic maneuvers.
• HRV analysis is a valuable tool for evaluating workload in flight conditions and enhancing the man-machine interface.