Measurements of blood flow and blood pressure under different indoor temperature and body postural conditions, and development of a new human simulation model

Numerical simulation with human thermophysiological model is one of the useful methods in order to evaluate the health risks caused by severe thermal environments. In addition, sudden changes in blood pressure (BP) and inadequate blood flow are key factors of those health problems. Therefore, we are developing a new human thermophysiological model, which can predict BP and blood flow as well as body temperature. In this study, we measured human physiological responses including BP and blood flow, because little experimental data on BP and blood flow were available to be referred. The measurements were carried on a healthy young man under three different conditions; 28^oC Sedentary, 35^oC Sedentary and 28^oC Standing. The BP was measured with the oscillometric method, and the blood flow was measured with an ultrasound imaging equipment and a laser blood flow meter. In these measurements, we observed the quantitative changes in blood flow, BP, stroke volume and heart rate due to indoor temperature and body position. On the other hand, we developed a simulation model of the cardiovascular system to be integrated into the new human model. The simulation results by this model were found to be reasonably matched with the measurements.