Abstract
The purpose of this study is to identify a major factor of ambiguity of nasal cycle from the viewpoint of contingency of each breathing. The waveform of nasal breathing measured with thermistors was converted to time-series data of the breathing volume, and multivariate autoregressive model was adopted to the shift. The experimental data showed that both of nasal breathings drifted according to a similar pattern in the morning and at night, while each side behaved independently in the daytime. These results suggested that the nasal cycle easily changes due to disturbances although each side has similar pattern of output.
