Patent ID: 9681853
Date: 2017-06-20
CPC Classifications: A61B,G01F

Claim:
1. An ultrasonic transducer apparatus for receiving a signal indicative of a velocity of a fluid containing ultrasound scatterers flowing through a lumen having an axis, the apparatus comprising: a cylindrical non-diffraction-grating transducer adapted to be wrapped around the circumference of the lumen and coupled to a number of electrode elements for exciting an ultrasound beam perpendicular to the axis of said cylindrical non-diffraction-grating transducer; a cylindrical diffraction-grating transducer disposed in a close proximity to the cylindrical non-diffraction-grating transducer and coupled to a number of electrode elements, wherein said cylindrical diffraction-grating transducer is configured to be wrapped around the circumference of the lumen to form a receiving beam, wherein wavefronts of said receiving beam from opposite walls of said cylindrical diffraction-grating transducer form multiple equiphase planes perpendicular to the axis of the cylindrical diffraction-grating transducer; wherein the cylindrical non-diffraction-grating transducer and the cylindrical diffraction-grating transducer are configured to receive at the cylindrical diffraction-grating transducer, when the cylindrical non-diffraction-grating transducer is excited, a scattered signal corresponding to the scatterers in the fluid crossing at least one of said equiphase planes, wherein the scattered signal is indicative of a velocity of the fluid along the axis of the lumen.