2012 Volume 17 Issue 1 Pages 1-13
This study was aimed at establishing a new index of respiratory regularity (IRR). By time-frequency analysis of a given respiratory curve, the IRR is defined as the frequency bandwidth of the respiratory component of power spectral density. The LIRR is also defined as the log-transformed IRR. The IRR was applied to respiratory curves of 14 subjects when the subjects breathed with controlled respiration and with natural respiration. The mean LIRR under controlled respiration was significantly lower compared with that under natural respiration. In addition, the characteristics of the IRR were examined by applying the IRR to computer-generated pseudo respiratory curves in the Appendix. In conclusion, the characteristics of the IRR were elucidated, and the IRR could quantitatively describe the subjects' respiratory regularity.