Biomechanics and Biomaterials Design Laboratory (BBDL)

Particle Image Velocimetry Flow Loop System

Brain aneurysms occur when the walls of a blood vessel inside the brain weaken and form a focal dilation. The rupturing of brain aneurysms can cause catastrophic damage to a patient's neurovascular health and in many cases premature mortality. Current treatments for aneurysms include surgical clipping, minimally invasive endovascular procedure with detachable coils, and flow diverting stents. In vitro flow tests of cerebral vascular systems with patient-specific aneurysm geometries are crucial for evaluating the efficacy and performance of new aneurysm treatment devices. Particle image velocimetry (PIV) is an optical technique that measures the fluid velocity field by tracking the movement of small particles within the fluid.

For this project, a PIV flow loop system is constructed to study aneurysm hemodynamics at a 100% size scale. Polydimethylsiloxane (PDMS) aneurysm phantoms are made to mimic the brain aneurysm geometry. The working fluid of this system is made of a mixture of water, glycerol, and fluorescent dyed particles. A laser sheet is aligned perpendicular to the direction of flow to illuminate the suspended particles for the high speed camera system to capture the particle movement through the phantom. The pulsatile pump, a pressure gauge, and a flow meter is used to monitor the flow of the working fluid to best replicate cerebral blood flow. The results of this research can be used to assist in testing the efficacy of various aneurysm treatments and in collection of high-fidelity flow-field data to validate brain aneurysm computational models.