A flexible blood flow phantom capable of independently producing constant and pulsatile flow with a predictable spatial flow profile for ultrasound flow measurement validations

The validation of the ultrasound time-domain correlation method of measuring blood flow has required the development of a flexible blood flow phantom capable of generating predictable flow profiles under a wide variety of conditions. The purpose of the phantom is to generate flow with well-known flow properties and not to mimic actual in vivo vessels. This paper describes a flow phantom which can independently generate both constant and pulsatile flow over a wide range of flow rates with a spatially fully developed laminar flow profile. It incorporates a computer-controlled pulsatile pump, which can produce different temporal pulsatile waveforms. The flow phantom also supports multiple vessels, different vessel sizes, as well as different attenuating media. The fluid most commonly used in the phantom is Sephadex mixed in water, and the probability density function of ultrasound reflected from Sephadex is experimentally determined and compared with that of blood. Examples of different constant and pulsatile flow experiments using the phantom are presented.