Abstract: A clutter and sensitivity phantom for calibrating an acoustic beam generating clinical Doppler ultrasound instrument, comprising: a fluid-filled tank into which the ultrasound instrument probe is immersed; first and second sound scattering belts; an acoustic beam splitter intermediate the ultrasound probe and the first and second sound scattering belts, the acoustic beam splitter being oriented at a predetermined angle relative to the ultrasound instrument and to respective ones of the first and second signal scattering belts for splitting and directing the acoustic beam generated by the ultrasound instrument so as to be reflected off both of the first and second sound scattering belts at an identical angle, whereby portions of the acoustic beam reflected off of the first and second sound scattering belts may be separately or simultaneously monitored.

Abstract: A positive displacement pump includes a reservoir for storing fluid, a cylinder for receiving and discharging the fluid and a piston within the cylinder for forcing the fluid into and out of the cylinder. The pump further includes a four-way valve having an inlet port connected to a reservoir, a pair of bidirectional ports connected to the opposite ends of the cylinder and an outlet port. Mechanisms are provided for receiving a user flow waveform expressed in terms of predetermined flow rate as a function of time and in response moving the piston and configuring the four-way valve to provide fluid flow from the reservoir through the valve and into one of the opposite ends of the cylinder, and from the other one of the opposite ends of the cylinder through the valve to the outlet port in accordance with the user flow waveform.