A multi-element nonlinear model of human circulatory-respiratory systems and its application in high-G study

The performance of modern combat aircraft, and the physiological limitation of pilots in tolerating high sustained acceleration, has led to the investigation of improved anti-G techniques. To predict physiological alterations under high G environments and evaluate effectiveness of protective measures, a multi-element, nonlinear mathematical model of human circulatory-respiratory system is developed based on the previous work. The modeling of pulmonary circulation and respiration system, as well as detailed models of abdomen and lower extremities, is added to previous studies regarding systemic circulation to see the influence of acceleration forces and anti-G measures on cardiopulmonary system. The simulation results have been shown to agree well with relevant experimental data on ophthalmic arterial pressure, with parallel human centrifuge experiments when wearing extended coverage anti-G suit, and be consistent with the experimental data obtained from reported centrifuge experiments using combined anti-G techniques.