| 摘要 |
PCT No. PCT/FI88/00170 Sec. 371 Date Apr. 12, 1990 Sec. 102(e) Date Apr. 12, 1990 PCT Filed Oct. 14, 1988 PCT Pub. No. WO89/03195 PCT Pub. Date Apr. 20, 1989.The invention concerns an ultrasound based measurement method and an apparatus for examining dense tissues in particular. According to the method, the measured object (17) is subjected to a high-frequency ultrasound signal, and echoes returning from the object (17) are converted into electric signals. According to the invention, either the object (17) or the ultrasound transducer (36) is vibrated at a low-frequency and the level of the low-frequency vibrating signal is detected from the echo signal, whereby interface locations of the vibrating object (17) can be determined from the maximum values of the detected low-frequency signal in relation to the transmitted high-frequency pulse. |
