品質工学の超音波ドプラ製品開発への応用(第4報)

－循環器ドプラ自動計測の総括－

抄録

Recently, medical ultrasonic diagnostic equipment with a Doppler auto-trace/auto-measure capability is being used in the field of cardiovascular and perinatal diagnosis. The equipment automatically traces the spectral Doppler envelope and measures indices of the blood-flow wavefbrm during each heart-beat. In this study, an automatic measuring system that automatically measures a diagnostic index of blood flow on the basis of diagnostic images was developed and optimized. Reductions ih both the length and variability of the procedures carried out by the user were achieved, and highly reliable measurements were obtained. An automatic measurement algorithm for blood flow into and out of the left ventricle, which had been difficult to measure automatically,was developed. Scores of 90% and higher were obtained, in comparison to 20% to 30% by conventional methods. Measurement accuracy and consistency also reached levels high enough for practical use. Quality engineering was used durinb system development by carrying out prototype simulation and automatic evaluation. Compared with conventional cut-and-try methods, less time was required for optimizing the adjustable parameters and the reliability of product performance was improved.