Analysis of gravity effect on human blood flow and skin temperature through postural change

¹ Graduate School of Integrative Science and Engineering, Tokyo City University, 1-28-1, Tamadzutsumi, Setagaya-ku, Tokyo, Japan
² Faculty of Engineering, Tokyo City University, 1-28-1, Tamadzutsumi, Setagaya-ku, Tokyo, Japan
³ Faculty of Engineering, Tokyo City University, 1-28-1, Tamadzutsumi, Setagaya-ku, Tokyo, Japan
⁴ Faculty of Science and Engineering, Tokyo City University, 1-28-1, Tamadzutsumi, Setagaya-ku, Tokyo, Japan
⁵ Faculty of Science and Engineering, Tokyo City University, 1-28-1, Tamadzutsumi, Setagaya-ku, Tokyo, Japan
⁶ Faculty of Science and Engineering, Tokyo City University, 1-28-1, Tamadzutsumi, Setagaya-ku, Tokyo, Japan

^* Corresponding author: hnagano@tcu.ac.jp

Abstract

The blood flow of human body has much impact on the thermo-physiological response. When person change the posture, the gravity acts changes its direction and thus the blood flow can be changed. It is hypothesized that the gravitational effects of postural changes affect blood flow and skin temperature, which in turn affect comfort. To verify this, in the present study, a subject experiment focusing on postural changes was conducted for two conditions (Case 1 and Case 2). In the Case 1 experiment, the subjects were asked to raise their hands for 10 minutes after 30 minutes of rest in the chair-sitting position. As a result, significant skin temperature change were observed in the upper arm, forearm, and hand. The largest skin temperature change was observed in the hands, which showed a decrease in skin temperature of approximately 1.2 °C. The change had influence on the whole-body average value. In Case 2, the subjects were placed in the supine position for 10 minutes after 30 minutes of rest in the chair position. As a result, a decrease in skin temperature of approximately 1 °C was observed on the hands and 0.5 °C in the foot was observed.