| 摘要 |
PURPOSE:To eliminate work of selecting a filter and eliminate a noise Doppler signal by an organ securely by providing a computation means which determines a frequency spectrum for a detected Doppler signal detecting blood flow information and reducing a compensation signal to a Doppler spectrum signal. CONSTITUTION:The level of each echo signal memorized in a digital scan converter DSC6 is compared with a threshold value memorized in an echo level detecting circuit 12. Every time an echo signal is obtained from a portion designated by a marker, a detecting signal is outputted to a sine wave signal generator 13. Time interval between the detection signals is measured at the sine wave signal generator 13, and the result of this measurement is converter into a frequency. A sine wave of the same frequency as this frequency is outputted for a compensation signal. At an FET computation circuit 9, the compensation from the sine wave signal generator 13 is processed for reduction to a frequency spectrum of a Doppler signal of blood flow speed inputted from an A/D converter circuit 8. A frequency spectrum can thus be obtained only for the blood flow speed with noise Doppler signals by motion of organs eliminated for the output of the FET computation circuit 9. |
