片倉 景義¹, 千田 彰一², 西谷 智彦², 松尾 裕英²

Kageyoshi KATAKURA¹, Shoichi SENDA², Tomohiko NISHIYA², Hirohide MATSUO²

¹日立製作所中央研究所, ²香川医科大学第2内科

¹Central Research Laboratory, Hitachi, Ltd., ²Department of Internal Medicine, Kagawa Medical School

キーワード : Pressure wave velocity, Correlation, Coherency, Doppler

The method proposed here for local measurement of blood pressure pulse wave propagation speed uses the complex cross correlation of ultrasonic Doppler signals. The signals are Doppler shifted by blood flow and measured at two closely spaced locations of a blood vessel.
The usual Doppler shift measured for blood flow is about 1 kHz, a propagation delay as small as 1 ms can be measured between adjacent locations.
To improve the coherency between the two Doppler signals, they are processed.
Sharp correlation peak is obtained after this processing for signals taken from carotid artery.