A microcirculation phantom for performance testing of blood perfusion measurement equipment

Objective: This paper describes a new flow phantom, designed to simulate slow, small volume flow, such as that found in the capillary beds. Existing flow phantoms imitate flow in blood vessels with a narrow flow area and the flow velocities are normally not extendible down to capillary blood flow velocities. Recent progress in ultrasonic blood perfusion measurements has resulted in devices that operate at blood flow velocities of the order 0.1−5 m/s and flow that is spatially and directionally distributed over the sample volume. Method: The phantom uses a ball of spatially random-oriented thin plastic tubes to carry scatterers through the sample volume. To avoid stationary echoes, and thereby ensure that the ultrasound reflections emanate mainly from the circulating blood mimicking particle suspension inside the tubing, the surrounding liquid has been acoustically matched to the tubing material. Results: The phantom has been tested on a novel blood perfusion measurement equipment and shown to set up a reasonably reproducible approximation of blood perfusion in tissue. Conclusion: It is believed that the design of the phantom is satisfactory for mimicking blood perfusion.