Patent ID: 7654960

Claim:
A method for ultrasound measurement of at least one of an opening surface area of an orifice through which a fluid flows, the volumetric flow rate through the orifice and the flow volume through the orifice, comprising the steps of: sonifying a region near an orifice through which bodily fluid is flowing by directing at least one transmit beam from an ultrasonic transducer toward said orifice; sensing a plurality of measurement beams using said ultrasonic transducer, each one of said measurement beams having a respective measurement area, said measurement areas being offset spatially and partially overlapping, said measurement beams comprising Doppler signals backscattered from the respective measurement areas, said measurement areas collectively encompassing said orifice; sensing at least one reference beam using said ultrasonic transducer, said at least one reference beam having a measurement area which is within said orifice, said reference beam comprising Doppler signals backscattered from the measurement area of said reference beam; evaluating said at least one reference beam to determine a reference value, said reference value comprising a Doppler power calibration coefficient; and cumulatively evaluating the Doppler signals within said plurality of measurement beams in conjunction with said reference value to determine at least one of the opening surface area of the orifice, the volumetric flow rate through the orifice, the flow volume through the orifice, and any value proportional thereto; wherein the Doppler signals of each measurement beam contribute to the overall value of said opening surface area, said volumetric flow rate, or said flow volume.