This study investigates the relationship among human metabolism rate, heart rate, and CO2 concentration in a sealed suit and provides a basis for real-time prediction of human metabolism rate in the suit. The suit is placed in a climate simulation chamber to minimize the effect of convective heat transfer with the environment as much as possible, the human metabolism experiment is performed in eight adult males under different conditions. The fan and pump operate during the experiment to provide gas purification and temperature and humidity control for the internal environment of the suit. The experimental results show that as the exercise load increases, the heart rate and CO2 concentration in the mouth and nose area increase and the metabolism rate increases. The changes in the metabolism rate are positively correlated with the heart rate and CO2 concentration. The linear calculation formulas of the volunteers between the human metabolism rate and heart rate as well as CO2 in the mouth and nose area are obtained through regression calculation. The study shows the prediction of human metabolism rate in a sealed suit is feasible using heart rate and CO2 .
Li et al. (Sun,) studied this question.