Working With the Food and Drug Administration's Center for Devices to Advance Regulatory Science and Medical Device Innovation

Malinauskas, Richard A.; Saha, Anindita; Sheldon, Murray

doi:10.1111/aor.12505

Cited by 8 publications

(3 citation statements)

References 4 publications

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“…Choosing a PC with channel width equal to 1.5 mm for Re τ = 80 and assuming blood viscosity μ = 0.0035 Pa s, the shear stress at the wall, τ w , was calculated to be 35.16 Pa, with friction velocity u � = 0.183 m/s. The Reynolds number for turbulent PF can be related to the Reynolds number for flow in the typical centrifugal PLOS ONE blood pump that was offered as part of the Food and Drug Administration critical path initiative for simulations [25,[34][35][36]. The case of flow of blood at 7 lt/min at Re = 3661 in a 1.5mm diameter pipe corresponds to a mean velocity of 1.990m/s, which when compared to the mean velocity of 16.68 in viscous wall units of the Re τ = 300 simulation gives u � = 0.1208 m/s and τ w = 14.95Pa.…”

Section: Computational Approachmentioning

confidence: 99%

Computations of the shear stresses distribution experienced by passive particles as they circulate in turbulent flow: A case study for vWF protein molecules

et al. 2022

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The stress distribution along the trajectories of passive particles released in turbulent flow were computed with the use of Lagrangian methods and direct numerical simulations. The flow fields selected were transitional Poiseuille-Couette flow situations found in ventricular assist devices and turbulent flows at conditions found in blood pumps. The passive particle properties were selected to represent molecules of the von Willebrand factor (vWF) protein. Damage to the vWF molecule can cause disease, most often related to hemostasis. The hydrodynamic shear stresses along the trajectories of the particles were calculated and the changes in the distribution of stresses were determined for proteins released in different locations in the flow field and as a function of exposure time. The stress distributions indicated that even when the average applied stress was within a safe operating regime, the proteins spent part of their trajectories in flow areas of damaging stress. Further examination showed that the history of the distribution of stresses applied on the vWF molecules, rather than the average, should be used to evaluate hydrodynamically-induced damage.

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Section: Computational Approachmentioning

confidence: 99%

Computations of the shear stresses distribution experienced by passive particles as they circulate in turbulent flow: A case study for vWF protein molecules

et al. 2022

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“…Blood is shear‐thinning and thixotropic, with an apparent viscosity that can increase by more than an order of magnitude at low shear rates . Despite these non‐Newtonian characteristics, the use of a Newtonian model is reasonable in simulating continuous flow blood pumps, because the viscosity of human blood is effectively shear‐independent at shear rates above 100 s −1 .…”

Section: Considerations For Modeling Flow and Hemolysis In Blood Pumpsmentioning

confidence: 99%

“…The first study began in 2008 to evaluate CFD as a biomedical research tool using a simple nozzle model. The second study is ongoing and is evaluating CFD predictions and limitations in characterizing flow and predicting blood damage in a centrifugal blood pump . The FDA will provide hemolysis measurements using porcine blood at an operating temperature of 25°C in the experimental setup shown in Fig.…”

mentioning

confidence: 99%

Flow‐Field Simulations and Hemolysis Estimates for the Food and Drug Administration Critical Path Initiative Centrifugal Blood Pump

et al. 2017

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The design of blood pumps for use in ventricular assist devices, which provide life-saving circulatory support in patients with heart failure, require remarkable precision and attention to detail to replicate the functionality of the native heart. The United States Food and Drug Administration (FDA) initiated a Critical Path Initiative to standardize and facilitate the use of computational fluid dynamics in the study and development of these devices. As a part of the study, a simplified centrifugal blood pump model generated by computer-aided design was released to universities and laboratories nationwide. The effects of changes in fluid rheology due to temperature, hematocrit, and turbulent flow on key metrics of the FDA pump were examined in depth using results from a finite volume-based commercial computational fluid dynamics code. Differences in blood damage indices obtained using Eulerian and Lagrangian formulations were considered. These results are presented and discussed awaiting future validation using experimental results, which will be released by the FDA at a future date.

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Hemolysis estimation in turbulent flow for the FDA critical path initiative centrifugal blood pump

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O’Rear

et al. 2021

Biomech Model Mechanobiol

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Working With the Food and Drug Administration's Center for Devices to Advance Regulatory Science and Medical Device Innovation

Cited by 8 publications

References 4 publications

Computations of the shear stresses distribution experienced by passive particles as they circulate in turbulent flow: A case study for vWF protein molecules

Computations of the shear stresses distribution experienced by passive particles as they circulate in turbulent flow: A case study for vWF protein molecules

Flow‐Field Simulations and Hemolysis Estimates for the Food and Drug Administration Critical Path Initiative Centrifugal Blood Pump

Hemolysis estimation in turbulent flow for the FDA critical path initiative centrifugal blood pump

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