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:
Nov. 19, 1991
Filed:
Dec. 19, 1989
Abstract
An ultrasonic Doppler blood flow velocity detection apparatus comprises: a signal producing circuit for producing trigger pulses, a sampling clock signal having a given phase relation with the trigger pulses, and a pair of quadrature signals of a given frequency in response to the trigger pulses. A transducer transmits also receives ultrasonic waves in response to the trigger pulses; The transducer also receives ultrasonic waves reflected back by an ultrasonic-wave reflective object and converts the received ultrasonic waves into an electric echo signal. A Doppler shift detection circuit, responsive to the pair of quadrature signals and the echo signal, detects the Doppler shift. An averaging circuit, responsive to the sampling clock, and the Doppler shift; averages plural time-different values of the Doppler shift, thereby producing a signal indicative of flow velocity of the ultrasonic-wave reflective object. The detection apparatus may further comprise a weighting circuit responsive to the output of the Doppler detection circuit and the sampling clock signal for weighting every value of the plural time-different values.