2005 Volume 13 Issue 6 Pages 57-65
Doppler auto trace, a method that automatically traces the envelope of the Doppler spectrum and thereby determines the maximum flow velocity in every systolic cycle, has come into recent use for ultrasonic diagnosis of circulatory organs and blood flow in the brain etc,, because through automation, it saves time and reduces operator-dependent variation. In practice, however, adequate trace performance is difficult to obtain by system setup alone, because the envelope waveform shape and Doppler sensitivity vary depending on the patient and the site being diagnosed. To improve the trace performance, in this study a simulation was carried out to optimize the control parameters of the signal processor for every diagnostic site. As a result, for diagnostic sites with lower Doppler sensitivity, such as the vertebral artery and middle cerebral artery, variation was reduced to approximately one-third the variation occurring in a conventional Doppler auto trace (i.e., the signal-to-noise ratio was reduced by approximately 10 db). Compared wjth conventional trial-and-error methods, our method reduced the time required for parameter optimization and made development more efficient.
