Integrated Thermofluid Lumped Parameter Model for Analyzing Hemodynamics in Human Fatigue State.

Area of Science:

• Physiology
• Biomedical Engineering
• Thermal Modeling

Background:

• Driving while fatigued poses significant risks, leading to accidents.
• The physiological mechanisms underlying fatigue remain insufficiently understood.
• Peripheral temperature changes are potential indicators of fatigue.

Purpose of the Study:

• To investigate the cardiovascular system's response to fatigue.
• To infer fatigue-induced changes using peripheral skin temperature.
• To develop an integrated model for fatigue mechanism analysis.

Main Methods:

• Constructed a full-body thermal model with variable blood perfusion.
• Integrated a cardiovascular system model using lumped parameters.
• Adjusted cardiovascular parameters (peripheral resistance, heart rate) to match experimental skin temperatures from induced fatigue.

Main Results:

• Fatigue led to decreased heart rate and blood pressure.
• Peripheral skin resistance in hands and head increased with fatigue.
• Reduced blood flow to extremities caused lower skin temperatures during fatigue.

Conclusions:

• The integrated model successfully elucidated fatigue's effect on the cardiovascular system.
• Decreased heart rate and increased peripheral resistance are key indicators of fatigue.
• Findings can enhance the accuracy of human fatigue monitoring systems.