| 摘要 |
<p>PURPOSE:To operate with high accuracy the power spectrum of the detection output of an utrasonic wave Doppler blood flow meter, by providing a square operation data ROM, an overflow detector and a digital saturation circuit respectively. CONSTITUTION:The signals lines 51 and 52 form an OVF (overflow) bus 38. When an OVF is generated during a square operation with a square data ROM 36, an eight input buffer of a digital saturation circuit 40 is set in an ACTIVE state and sends an input data 7F (hexadecimal) to an output bus 29. Then the Fourier vector value of the reflected signal sent from the erythrocytes estimated to be within the range of bit positions 10-0 of a bus 35 is converted by the ROM36. While the Fourier vector value of an intensive reflected signal is considred to exceed the input range of the ROM36 and detected by an OVF detector 39. Then the circuit 40 delivers the digital saturation value.</p> |
