In vitro flow study in a compliant abdominal aorta phantom with a non-Newtonian blood-mimicking fluid

• Published in: Journal of biomechanics Vol. 130; p. 110899
• Main Authors: Moravia, Anaïs, Simoëns, Serge, El Hajem, Mahmoud, Bou-Saïd, Benyebka, Kulisa, Pascale, Della-Schiava, Nellie, Lermusiaux, Patrick
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.01.2022; Elsevier Limited; Elsevier
• Subjects: Aneurysms; Aorta; Aorta, Abdominal; Aortic dissection; Aqueous solutions; Biomechanics; Blood; Blood circulation; Blood Flow Velocity; Blood-mimicking fluid; Circulatory mock loop; Compliance; Coronary vessels; Decision analysis; Decision making; Flow distribution; Flow paths; Flow velocity; Flow visualization; Fluid dynamics; Fluid flow; Fluid mechanics; Fluids; Geometry; Hemodynamics; Humans; In vivo methods and tests; Mechanical properties; Mechanics; Medical imaging; Mimicry; Models, Cardiovascular; Newtonian fluids; Non Newtonian fluids; Non-Newtonian; Particle image velocimetry; Physics; Physiology; PIV; Polymers; Pulsatile Flow; Rheology; Shear rate; Shear thinning (liquids); Silicones; Simulators; Stress distribution; Stress, Mechanical; Thinning; Velocity; Velocity distribution; Viscosity; Wall shear stresses; Xanthan; Xanthan gum; Circulatory mock loop; Aorta; Blood-mimicking fluid; Non-Newtonian; PIV
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/j.jbiomech.2021.110899

In vitro aortic flow simulators allow studying hemodynamics with a wider range of flow visualization techniques compared to in vivo medical imaging and without the limitations of invasive examinations. This work aims to develop an experimental bench to emulate the pulsatile circulation in a realistic aortic phantom. To mimic the blood shear thinning behavior, a non-Newtonian aqueous solution is prepared with glycerin and xanthan gum polymer. The flow is compared to a reference flow of Newtonian fluid. Particle image velocimetry is carried out to visualize 2D velocity fields in a phantom section. The experimental loop accurately recreates flowrates and pressure conditions and preserves the shear-thinning properties of the non-Newtonian fluid. Velocity profiles, shear rate, and shear stress distribution maps show that the Newtonian fluid tends to dampen the observed velocities. Preferential asymmetrical flow paths are observed in a diameter narrowing region and amplified in the non-Newtonian case. Wall shear stresses are about twice higher in the non-Newtonian case. This study shows new insights on flow patterns, velocity and shear stress distributions compared to rigid and simplified geometry aorta phantom with Newtonian fluid flows studies. The use of a non-Newtonian blood analog shows clear differences in flows compared to the Newtonian one in this compliant patient-specific geometry. The development of this aortic simulator is a promising tool to better analyze and understand aortic hemodynamics and to aid in clinical decision-making.