A 3D colour Doppler ultrasound imaging system for in vitro estimation of flow parameters downstream of prosthetic heart valves

The paper presents a 3D colour ultrasound imaging system for the estimation of flow parameters downstream of prosthetic heart valves. The system consists of an ATL Ultramark 9 HDI colour Doppler ultrasound machine with a 38 mm aperture and a 5 MHz high resolution linear array transducer, a 3D ultrasound imaging system, and an in vitro circulation system under which the prosthetic heart valves are tested. Preliminary results obtained in the case of St. Jude prosthetic heart valves show that the technique can be used successfully to estimate the mean flow velocity, the cross-sectional area of the forward flow, and the impact of the jets. Further work is required for more quantitative evaluation of flow velocity. In this context, some suggestions are presented in order to improve the velocity estimation