Application of heat and steam generating sheet to the human body (II) Physiological responses of the sheet applied to the abdominal region

Abstract

We present a basic study for a heat-and steam-generating sheet (HS sheet) in the study I. Then, in this study II, we present the effect of the influence of HS sheet on the peripheral hemodynamics and autonomic nervous activity, when applied to the abdomen. The following items were measured: abdominal skin temperature, fingertip skin temperature of the hand, oxygen saturation (StO₂) in the fingertip of the hand measured by near infrared spectroscopy, pupillary light reflex by closed-loop method, changes in R-R interval in electrocardiography (ECG), and percutaneous electrogastrography (EGG). For the control, a heat-generating sheet without steam was used. In this study, application of a HS sheet to the abdomen significantly prevented the decrease of the fingertip skin temperature and StO2 (p<0.05), suggesting that peripheral blood flow was improved. In addition, HS sheet application showed dominance of parasympathetic activity in the following items: an increase in the pupillary light reflex (p<0.01), an increase in the HF component and a decrease in the LF/HF component in the ECG R-R interval. The amplitude in EGG seemed to increase during application of HS sheet until for a while after its removal. Therefore, the application of the HS sheet to the abdomen is suggested to improve peripheral hemodynamics and produce parasympathetic predominance. [Jpn J Physiol 55 Suppl:S189 (2005)]