Table of Contents
ISRN Biomedical Imaging
Volume 2013, Article ID 850303, 6 pages
Research Article

Automatic Valve-Rejection Algorithm for Cardiac Doppler Ultrasound Systems

1Toshiba Medical Systems Corporation, 1920-2, Usuba, Otawara, Tochigi 3240035, Japan
2Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 2238522, Japan

Received 7 February 2013; Accepted 26 February 2013

Academic Editors: R. Guldiken and B. Tomanek

Copyright © 2013 Tatsuro Baba et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In recent years, blood flow diagnosis using Doppler ultrasound systems has become popular. Using these systems, the peak velocity of blood flow is automatically traced. However, because valve signals are mixed with the blood flow signals in a heart chamber, automatic measurements of blood flow are not correctly recorded. To solve this problem, we developed a novel method that adopted system identification. We applied a mathematical model with an electrocardiographic waveform as the input and a trace waveform of the peak velocity as the output. Several mathematical models with different structures and orders were compared to select the optimal model. Using this model, we developed a system that could automatically eliminate the valve signal. We also evaluated our valve-rejection algorithm using simulations based on actual clinical data.