2014 年 13 巻 4 号 p. 269-277
The main purpose of this study is to explore physiological parameters that are usable for tactile softness differentiation. Two pillows and a cushion which were different in tactile softness (perceived compressibility and resilience) were chosen as the samples. 10 healthy students participated in the physiological test. Each of them was tested on three days, twice a day with the same sample involved. Each subject was required to keep quiet, compress the sample and keep quiet again in succession during a whole test. ECG (electrocardiography), PPG (photoplethysmography) and RSP (respiration) signals were recorded simultaneously during each physiological test. Several parameters indicating cardiovascular and respiratory reactions were calculated based on these signals. The statistical analysis results revealed that, HFnorm (normalized power of high-frequency components) calculated from the power spectrum of PWTT (pulse wave transmitting time) might be a very promising parameter which can be used for tactile softness differentiation.