Title :
Comparison of techniques for assessing pulmonary input impedance spectra
Author :
Ha, Belinda ; Lucas, Carol L. ; Henry, G. William ; Frantz, Elman G. ; Ferreiro, Jose I. ; Severi, Rossana ; Wilcox, Benson R.
Author_Institution :
Dept. of Surg. & Pediatrics, North Carolina Univ., Chapel Hill, NC, USA
Abstract :
A six-element lumped parameter model of the pulmonary circulation was used to evaluate two signal-averaging techniques for calculating the pulmonary input impedance spectra of normal lambs. Pulmonary artery pressure and pulmonary artery flow data obtained simultaneously in the main pulmonary artery were subjected to time-domain averaging and frequency-domain averaging techniques. Input impedance was determined by a cross-power spectral method designed to retain the periodicity of the signals. Preliminary studies indicate that the impedance spectra determined from noise-free input flow data to the model closely approximated the model-derived impedance spectra for a wide range of heart rates. The addition of noise signals to the noise-free input data produced impedance spectra that were consistently in agreement with model spectra for the lower-order (1-3) harmonics but not for the higher-order terms
Keywords :
haemodynamics; lung; signal processing; spectral analysis; 6-element lumped parameter model; cross-power spectral method; frequency-domain averaging; harmonics; heart rate; noise signals; noise-free input data; normal lambs; pulmonary artery flow; pulmonary artery pressure; pulmonary input impedance spectra; signal periodicity; signal-averaging techniques; time-domain averaging; Arteries; Character generation; Heart rate; Impedance; Noise figure; Noise generators; Noise shaping; Signal generators; Surgery; Velocity measurement;
Conference_Titel :
Engineering in Medicine and Biology Society, 1989. Images of the Twenty-First Century., Proceedings of the Annual International Conference of the IEEE Engineering in
Conference_Location :
Seattle, WA
DOI :
10.1109/IEMBS.1989.95596