We discussed the simple method about a subjective evaluation of cooking odor diffusion from kitchen to a dining (or living) room. The subjects standardized their sensitivity by progressive amount of a standard material (2,4-decadienal) before each evaluating. And the subjects took a rest periodically during the evaluation, in order to exclude decreasing of sensitivity by olfactor y adaptation. These evaluating results accord with results of the thermal environment measurement and the visual observation by the smoke flow in the room. Prof., Faculty of Education, Niigata Univ., M. Home Ec. Graduate School, Nara Women's Univ. Kansai

The aim of this study is to develop a method for measuring the respiratory waveform using non-contact electrodes during bathing. To determine the most appropriate electrode arrangement, we modeled a composite system consisting of a body submerged in bath water. We calculated the frequency dependence of the impedance amplitude using a three-dimensional finite difference method (3D-FDM). The simulation results showed that an increase in chest size due to inspiration caused a decrease in the impedance amplitude in the frequency range of 0.1 Hz to 1 MHz. Next, bioelectric impedance (BEI) was measured in the frequency range of 4 kHz to 4 MHz at the maximum-end-expiration and maximum-end-inspiration stages. BEI results were consistent with those obtained from the model simulations. We found that 1 MHz was the appropriate frequency for measuring the respiratory waveform, and the time dependence of the impedance amplitude was measured at 1 MHz. The impedance amplitude agreed well with the respiratory waveform obtained from rubber strain gauge plethysmography, which was used as a reference.

Preliminary theoretical calculations and examinations were carried out to develop a method of non-contact respiratory monitoring during bathing to detect abnormal respiration using the bioelectric impedance (BEI) technique. First, theoretical calculations regarding the frequency-dependence of the impedance amplitude were made using a two-dimensional model consisting of a circular body and bath water surrounding the body. The body consisted of concentric layered circles representing the lung and the body fluid. The calculations showed that increases in chest size due to inspiration cause a decrease in the impedance amplitude in the frequency range from 1 kHz to 100 MHz. Next, BEI measurements were carried out from 4 to 400 kHz with the pair of electrodes placed in the vicinity of the chest at the maximumend-expiration and maximum-end-inspiration stages. These provided results consistent with those obtained from the theoretical calculations. Third, the time-dependence of the impedance amplitude was measured at 10, 100, and 400 kHz, respectively. At all of these frequencies, the impedance amplitude corresponded well with the respiratory waveform obtained from rubber strain gauge plethysmography, which was used as a reference.