Design Optimization and Performance Studies of an Adult Scale Viscous Impeller Pump for Powered Fontan in an Idealized Total Cavopulmonary Connection

A hybrid large eddy simulation (LES) and immersed boundary method (IBM) computational approach is used to make quantitative predictions of flow field statistics within the Food and Drug Administration’s (FDA) idealized medical device. An in-house code is used, hereafter (W enoHemo™), that combines high-order finite-difference schemes on structured staggered Cartesian grids with an IBM to facilitate flow over or through complex stationary or rotating geometries and employs a subgrid-scale (SGS) turbulence model that more naturally handles transitional flows [2]. Predictions of velocity and wall shear stress statistics are compared with previously published experimental measurements from Hariharan et al. [6] for the four Reynolds numbers considered.

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“…Pressure is also commonly used to study the power loss inside medical devices, as well as characterize the performance of pumps ([8]). Fig.…”

Section: Resultsmentioning

confidence: 99%

Large Eddy Simulation of FDA’s Idealized Medical Device

Delorme

Anupindi

Frankel

2013

Cardiovasc Eng Tech

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“…The VIP concept is inspired by the Von Karman viscous pump principle (Panton, 2005) and the current design resembles a double-sided cone with six mild vanes (Kennington et al, 2011). The height of the pump is 17.6 mm and its maximum diameter is 20.3 mm .…”

Section: Resultsmentioning

confidence: 99%

“…This will ease the symptoms of Fontan failure and allow the physician to take care of the patient as a “biventricular Fontan”. Preliminary performance, biocomptability and CFD studies of a rigid prototype have demonstrated the feasibility of the Viscous Impeller Pump (VIP) (Kennington et al, 2011; Giridharan et al, 2012). …”

Section: Introductionmentioning

confidence: 99%

Large eddy simulation of powered Fontan hemodynamics

Delorme

Anupindi

Kerlo

et al. 2013

Journal of Biomechanics

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Children born with univentricular heart disease typically must undergo three open heart surgeries within the first 2–3 years of life to eventually establish the Fontan circulation. In that case the single working ventricle pumps oxygenated blood to the body and blood returns to the lungs flowing passively through the Total Cavopulmonary Connection (TCPC) rather than being actively pumped by a subpulmonary ventricle. The TCPC is a direct surgical connection between the superior and inferior vena cava and the left and right pulmonary arteries. We have postulated that a mechanical pump inserted into this circulation providing a 3–5 mmHg pressure augmentation will reestablish bi-ventricular physiology serving as a bridge-to-recovery, bridge-to-transplant or destination therapy as a “biventricular Fontan” circulation. The Viscous Impeller Pump (VIP) has been proposed by our group as such an assist device. It is situated in the center of the 4-way TCPC intersection and spins pulling blood from the vena cavae and pushing it into the pulmonary arteries. We hypothesized that Large Eddy Simulation (LES) using high-order numerical methods are needed to capture unsteady powered and unpowered Fontan hemodynamics. Inclusion of a mechanical pump into the CFD further complicates matters due to the need to account for rotating machinery. In this study, we focus on predictions from an in-house high-order LES code (WenoHemo™) for unpowered and VIP-powered idealized TCPC hemodynamics with quantitative comparisons to Stereoscopic Particle Imaging Velocimetry (SPIV) measurements. Results are presented for both instantaneous flow structures and statistical data. Simulations show good qualitative and quantitative agreement with measured data.

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“…Support considerations include two microaxial pumps in the vena cava(e) [5] or a single percutaneous pump which can augment Fontan flow in all 4 axes of the TCPC without risk of venous pathway obstruction [6–8]. Once a safe and reliable device becomes available, it will be possible to provide high-volume, low-pressure flow augmentation similar to normal right ventricular hemodynamics to alleviate the sequelae of elevated systemic venous pressure and low cardiac output.…”

Section: Introductionmentioning

confidence: 99%

Cavopulmonary Assist for the Failing Fontan Circulation

et al. 2014

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Mechanical circulatory support - either ventricular assist device (VAD, left-sided systemic support) or cavopulmonary assist device (CPAD, right-sided support) - has been suggested as treatment for Fontan failure. The selection of left- vs. right-sided support for failing Fontan has not been previously defined. Computer simulation and mock circulation models of pediatric Fontan patients (15–25 kg) with diastolic, systolic, and combined systolic and diastolic dysfunction were developed. The global circulatory response to assisted Fontan flow using VAD (HeartWare HVAD, FL) support, CPAD (Viscous Impeller Pump, IN) support, and combined VAD and CPAD support were evaluated. Cavopulmonary assist improves failing Fontan circulation during diastolic dysfunction but preserved systolic function. In the presence of systolic dysfunction and elevated ventricular end-diastolic pressure (VEDP), VAD support augments cardiac output and diminishes VEDP, while increased preload with cavopulmonary assist may worsen circulatory status. Fontan circulation can be stabilized to biventricular values with modest cavopulmonary assist during diastolic dysfunction. Systemic VAD support may be preferable to maintain systemic output during systolic dysfunction. Both systemic and cavopulmonary support may provide best outcome during combined systolic and diastolic dysfunction. These findings may be useful to guide clinical cavopulmonary assist strategies in failing Fontan circulations.

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Design Optimization and Performance Studies of an Adult Scale Viscous Impeller Pump for Powered Fontan in an Idealized Total Cavopulmonary Connection

Cited by 14 publications

References 18 publications

Large Eddy Simulation of FDA’s Idealized Medical Device

Large Eddy Simulation of FDA’s Idealized Medical Device

Large eddy simulation of powered Fontan hemodynamics

Cavopulmonary Assist for the Failing Fontan Circulation

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