The Change of the Pressure Sensation and the Plethysmogramby Wearing the Pressure Suit

Abstract

The purpose of this study is to investigate the change of the pressure sensation and the finger and the finger and the toe tip plethysmogram during the period of the pressurization on the different pressure area by using the pressure suit which can apply pressure to the human body surface by the region individually. There are two cases for pressurization. One case is that the pressure applies to each region to investigate the regional characteristics against the pressure. The other is that the pressure applies to more than two regions at the same time to investigate the effect of the increase of the pressure area. The pressure was recorded when the subjects felt the following pressure sensation of "slightly tight" "tight", or "fairly tight" The plethysmogram of the both hands (Digitus II) and the feet (Digitus I) were measured. The results were as follows. In the case of the pressure applied to each region, the chest and back was the most sensitive region against the same pressure. The pressure against the same pressure sensation became small according as the pressure area increased except the pressure applied to the trunk. When the pressure applied to the whole body, the pressure against the same pressure sensation was the smallest. The degree of decrease of the finger and toe tip plethysmogram were not changed by the pressure area and the increment of the pressure area when the pressure applied to the limbs. When the pressure applied to the upper extremities, the degree of the decrease of the finger tip plethysmogram was larger than that of the toe tip plethysmogram when the pressure applied to the lower extremities against the same pressure. The finger and the toe plethysmograms were also decreased by the pressure applied to the chest and back. In the case of the pressure applied to the whole body, the decrease of the plethysmograms were at almost the same degree compared with those obtained by the pressure applied to the limbs. The results suggest that 1) attention should be given to the pressure methods of the chest and back because of the high sensitivity against the pressure, 2) the increment of the pressure area influence on the psychological discomfort and not on blood flow, and 3) if the pressure applies to the whole body at the same pressure, the physiological load of the upper extremities may become large compared with that of lower extremities.