The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 1990
Filed:
Apr. 21, 1989
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An ultrasonic Doppler blood flow velocity detection apparatus comprises: a pulse generation circuit for generating pulses at a predetermined interval; a transducer for transmitting ultrasonic waves in response to each of the pulses and for receiving reflected ultrasonic waves from a reflective object in the blood of a human body and converting the received ultrasonic waves into an electric echo signal; an extraction circuit for extracting signal components of first and second frequencies f1 and f2; a signal producing circuit for producing a signal having a frequency of .vertline.f1-f2.vertline. using output signals of the extraction circuit; a detection circuit for detecting amplitude of an output signal of the frequency difference signal producing circuit circuit and for phase-comparing the output signal with a reference signal; and a reference signal generation circuit for generating the reference signal of a predetermined frequency fr in response to each of the pulses, the predetermined frequency fr being approximately equal to the frequency difference .vertline.f1-f2.vertline.. The invention also discloses a method for detecting blood flow velocity.