Development of a Complex Flow Phantom for Diagnostic Imaging

Literature and market analysis have highlighted the lack of flow phantom technologies able to challenge innovative medical imaging devices, such as Ultrasound and Magnetic Resonance. A novel, cost-effective, compact and robust Complex Flow Phantom prototype was proposed. The design relies on the generation of stable, reproducible, predictable and controllable vortex rings. Vortex rings were chosen because bring together high stability and physiological relevance. The design was tested with multiple and independent measurement methods under challenging working conditions. Overall, it demonstrated to produce reproducible flows with variability always lower than +/- 10 %. This variability was assessed with regards to translational velocity, however, macro-flow reproducibility implies micro-flow stability. Computational Fluid Dynamics (CFD) and optical/video acquisitions were used as first methods to independently validate two early prototypes operating in air and water. CFD overall well approximate theoretical predictions but accuracy was insufficient to provide a reference standard. Overall, the early prototypes demonstrated encouraging stability and a Vortex Ring based Complex Flow Phantom prototype was manufactured. Laser PIV acquisitions were performed to establish flow reference standard values. Optical/video acquisitions were performed and results were compared with Laser PIV to assess the rigour of the methods. Results obtained by the two different measurement methods on two identically manufactured but different systems showed credible consistency. Conventional and advanced (Vector Flow Imaging) Ultrasound acquisitions were also performed on the design. An instrumentation pack was designed and is provided as tool for self-calibrating the phantom and for estimating flow reference values under different generating conditions. An MRI compatible version of the phantom was manufactured and was tested in laboratory. Design and experiments are supported by journal article and conference proceeding publications, poster and oral presentation in international conferences. The phantom is purchasable from Leeds Test Objects Ltd or can be manufactured in laboratory following the specifications provided.