An Investigation of Three-Dimensionality in the Penn State Pulsatile Pediatric Ventricular Assist Device
Open Access
- Author:
- Roszelle, Breigh Nonte
- Graduate Program:
- Bioengineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Keefe B Manning, Thesis Advisor/Co-Advisor
Keefe B Manning, Thesis Advisor/Co-Advisor - Keywords:
- particle image velocimetry
pediatric ventricular assist device
fluid mechanics - Abstract:
- Lack of organ availability remains one of the major obstacles in battling congenital heart disease through transplantation. This has led to the need for pediatric circulatory support devices to aid patients during the bridge-to-transplant time period. Penn State is currently developing a 12 cc pneumatically driven pediatric ventricular assist device (PVAD). One of the major concerns with assist devices is thrombosis, which can be a product of device fluid mechanics and therefore needs to be studied. Planar 2D particle image velocimetry has been used to observe whole field fluid mechanics of assist devices in the past. However, the decreased volume and increased curvature of the pediatric device has lead to more three-dimensionality, which makes the flow more difficult to interpret using 2D measurements. In this study planar measurements both parallel and normal to the diaphragm of the PVAD we acquired for the first time, in order to better analyze incidences of three-dimensionality. Measurements were taken in three planes parallel to the diaphragm and in six planes normal to the diaphragm, three in each of the ports. An acrylic model of the PVAD was placed in a mock circulatory loop that used a viscoelastic blood analog as a fluid. Both velocity flow maps and wall shear maps were obtained for each of the planes. The planes normal to the diaphragm confirmed flow features previously seen in the parallel planes including formation of the inlet jet, rotation within the device and areas of flow separation. The normal planes also identified new features, such as areas of regurgitation and stagnation. Obtaining data in the normal planes of the device helped to further understand the three-dimensional nature of the PVAD flow. It also confirmed that 2D measurements are fundamentally still a useful tool for this type of device.