@article{oai:niigata-u.repo.nii.ac.jp:00001956,
 author = {Hori, Jun-ichi and Saitoh, Yoshiaki and Kiryu, Tohru and Iijima, Taizo},
 issue = {6},
 journal = {IEICE transactions on information and systems, IEICE transactions on information and systems},
 month = {Nov},
 note = {The pressure waveforms indicated on a catheter manometer system are subject to serious distortion due to the resonance of the catheter itself, or the compliance of a particular transducer. Although several methods have been proposed for improving those characteristics, they have never been put into practice. We have focused on the transfer function of the catheter manometer, and made a pilot system, using the natural observation method. This method has been suggested as a means of studying the structure of the instantaneous waveform. In this manner, we were able to increase the bandwidth in the frequency domain and reduce the ringing in the time domain. Correction was performed automatically, using a step wave. Reproduction bf the waveform with a flushing device, was a task of equal simplicity, that allowed us to estimate the system parameters so that the response waveform became step-like. In the experiment, our system provided distortion-free left-ventricular pressure waveform measurements and exact evaluation of the cardiac pumping system. The values obtained came much closer to the original figures arrived at by the catheter-tip manometer system.},
 pages = {909--915},
 title = {Automatic Correction of Left-Ventricular Pressure Waveform Using the Natural Observation Method},
 volume = {E75-D},
 year = {1992}
}