An experimental study on the ergonomics indices of partial pressure suits

Mechanical and physiological effect of partial pressure suit: Experiment and numerical study

BACKGROUND

During high-altitude flight, the protection of the pilot is vital. A partial pressure suit may affect human physiology, especially circulatory physiology.

OBJECTIVE

The purpose of this study was to investigate how a partial pressure suit works.

METHOD

Ten subjects took part in the flight simulation experiments. Counter pressure at the chest, abdomen, thigh and shank were detected, together with physiological parameters such as heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR). A numerical model was also established to simulate hemo-physiological effects of the partial pressure suit.

RESULTS

The experiment's results show the non-uniform counter pressure distribution in different parts of the body. There is a linear, proportional relation between TPR and the pressurizing level. HR and MAP increase along with that of the pressure level. SV and CO decrease with the increase of the pressure level. The numerical model simulated the physiological effect of a partial pressure suit. The results were verified by experiment data. The simulation estimated the change of blood flow with the pressure level.

CONCLUSIONS

The numerical model provides a potential way to improve the protection of pilots.

Optimizing the physical ergonomics indices for the use of partial pressure suits

This study developed an ergonomic evaluation system for the design of high-altitude partial pressure suits (PPSs). A total of twenty-one Chinese males participated in the experiment which tested three types of ergonomics indices (manipulative mission, operational reach and operational strength) were studied using a three-dimensional video-based motion capture system, a target-pointing board, a hand dynamometer, and a step-tread apparatus. In total, 36 ergonomics indices were evaluated and optimized using regression and fitting analysis. Some indices that were found to be linearly related and redundant were removed from the study. An optimal ergonomics index system was established that can be used to conveniently and quickly evaluate the performance of different pressurized/non-pressurized suit designs. The resulting ergonomics index system will provide a theoretical basis and practical guidance for mission planners, suit designers and engineers to design equipment for human use, and to aid in assessing partial pressure suits.