TY - JOUR
AU - K. R. Lutchen , K. Yang , D. W. Kaczka , and B. Suki
AB -  of Biomedical KUN YANG, DAVID W. KACZKA, AND BELA SUKI Engineering, Boston University, Boston, Massachusetts 02215 alterations after bronchoconstriction (29, 39) or pulmonary edema (7,13) cause the frequency dependence and the levels of Rrs and Ers to become considerably elevated. Furthermore, the Rrs changes are largest at the lower frequencies (~0.2-0.5 Hz). In humans, the nature of the frequency and volume amplitude dependence has only recently received some attention (33) and, to our knowledge, has not been reported in human subjects with pulmonary disease. In human subjects there exists no efficient technique to acquire Rrs and Ers from 0 to 4 Hz. Moreover, interpretation is limited because of the lack of an appropriate manner to incorporate nonlinearities and frequency dependence into data analysis. One could methodically sequence through a series of sine wave oscillations at discrete frequencies and VTS [e.g., as was done by Barnas and co-workers (4,6-8)], but this protocol would be quite laborious and taxing and, hence, is not practical for clinical studies. An alternative would be to apply signals composed of several frequencies and to employ fast Fourier transform (FFT) techniques for estimating the impedance spectrum over the frequency range implicit in the driving signal’s 
TI - Optimal ventilation waveforms for estimating low-frequency respiratory impedance
JF - Journal of Applied Physiology
DA - 1993-07-01
UR - https://www.deepdyve.com/lp/the-american-physiological-society/optimal-ventilation-waveforms-for-estimating-low-frequency-respiratory-SyoH83TMy8
VL - 75
IS - 
DP - DeepDyve
ER -