Blood flow sensing device

Abstract

Abstract A pulsed ultrasound Doppler blood flow sensing device comprising: rate pulse signal generating means (5) for producing a rate pulse signal at a rate frequency (f r ); drive pulse signal generating means (6) for producing a drive pulse signal in response to the rate pulse signal; transducing means (7) for emitting ultrasound pulses into an object under diagnosis in response to a drive pulse signal from the drive pulse signal generating means and for converting echoes of the ultrasonic pulses returning from the object into electrical signals; sampling and holding means (11a, 11b) for sampling and holding only the electrical signals of the echoes returning from positions at a give depth of the object; band pass filter means (13a, 13b) for extracting only the Doppler frequency shift signals from the sampled and held signals, the band pass means having a band pass characteristic in which a variation of an attenuation degree is almost flat over a frequency band at least between -f/2 and +f,/2 except for a region in proximity to frequency 0; frequency analyzing circuit (14) for analyzing the frequencies of the Doppler frequency shift signals; signal processing means (15) for processing the frequency analyzed Doppler frequency shift signals to obtain Doppler shifts; and display means (16) for displaying blood flow signals which represent the obtaind Doppler frequency shifts and have frequencies at least between the frequencies -f, and +f r .

Inventors

• 👤 Kazuhiro Iinuma

Bibliographic Details