Abstract: A method of determining the volume flow of a fluid through a conduit usable with a single crystal, whereby at least one of the fluid and the conduit have energy-scattering interfaces. The method in one embodiment includes transmitting a known, uniform sound field through the fluid which illuminates the entire cross-sectional area of the conduit, obtaining the Doppler signal from the received signal such that the sampling region is normal to the direction of propagation of the sound field; and obtaining the integral of the power over this surface. A known volume of fluid totally within the conduit is then sampled for the reference power return therefrom and this reference power return is divided into the first moment of the power to produce a signal proportional to the volume flow of the fluid through the conduit.

Abstract: A catheter probe flow meter and method of determining the volume flow of a fluid through a conduit, at least one of the fluid and the conduit having energy-scattering interfaces. The method in one embodiment includes trasmitting at least two and receiving at least one or transmitting at least one and receiving at least two sound beams through the fluid, resolving the Doppler vectors into an average velocity vector for each transmitting/receiving combination, and resolving the resolved velocity vectors into their component parts.

Abstract: A catheter probe flow meter and method of determining the volume flow of a fluid through a conduit, at least one of the fluid and the conduit having energy-scattering interfaces. The method in one embodiment includes transmitting at least two and receiving at least one or transmitting at least one and receiving at least two sound beams through the fluid, resolving the Doppler vectors into an average velocity vector for each transmitting/receiving combination, and resolving the resolved velocity vectors into their component parts.