RESPIRATION IMPEDANCE MEASURING DEVICE AND METHOD, AND RESPIRATION IMPEDANCE DISPLAY METHOD

摘要

A respiration impedance can be continuously measured with very high accuracy by removing the noise. A loudspeaker (21) applies an air vibration pressure to the mouth cavity by an oscillation wave produced by frequency thinning so that different frequencies of the oscillation wave are thinned and the oscillation wave has only the remaining frequency components. The pressure in the mouth cavity is detected to determine the flow rate of respiration. A Fourier-transforming means (32) Fourier-transforms the obtained signal to obtain the spectrum. An extracting means (33) determines the respiration high-frequency component contributing as noisefrom the spectrum corresponding to the frequency components removed by the frequency thinning, subtracting the respiration high-frequency component from the spectrum corresponding to the remaining frequency components, and thus extracting the oscillation wave component. A computing means (34) divides the pressure component by the flow rate component for each frequency with respect to the extraction result.