scholarly journals Fluid–Structure Interaction Models of Bioprosthetic Heart Valve Dynamics in an Experimental Pulse Duplicator

2019 ◽  
Author(s):  
Jae Ho Lee ◽  
Alex D. Rygg ◽  
Ebrahim M. Kolahdouz ◽  
Simone Rossi ◽  
Stephen M. Retta ◽  
...  
Keyword(s):  
Heart Valves ◽  
Computational Models ◽  
Fluid Structure Interaction ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Pulse Duplicator ◽  
Valve Dynamics ◽  
Valve Opening ◽  
Surgical Valve Replacement

Computer modeling and simulation (CM&S) is a powerful tool for assessing the performance of medical devices such as bioprosthetic heart valves (BHVs) that promises to accelerate device design and regulation. This study describes work to develop dynamic computer models of BHVs in the aortic test section of an experimental pulse duplicator platform that is used in academia, industry, and regulatory agencies to assess BHV performance. These computational models are based on a hyperelastic finite element extension of the immersed boundary method for fluid--structure interaction (FSI). We focus on porcine tissue and bovine pericardial BHVs, which are commonly used in surgical valve replacement. We compare our numerical simulations to experimental data from two similar pulse duplicators, including a commercial ViVitro system and a custom platform related to the ViVitro pulse duplicator. Excellent agreement is demonstrated between the computational and experimental results for bulk flow rates, pressures, valve open areas, and the timing of valve opening and closure in conditions commonly used to assess BHV performance. In addition, reasonable agreement is demonstrated for quantitative measures of leaflet kinematics under these same conditions. This work represents a step towards the experimental validation of this FSI modeling platform for evaluating BHVs.

Fluid-Structure Interaction in Bi-Leaflet Mechanical Heart Valves

2007 ◽  
Author(s):  
Iman Borazjani ◽  
Liang Ge ◽  
Fotis Sotiropoulos ◽  
Lakshmi Prasad Dasi ◽  
Ajit Yogonathan
Keyword(s):  
Heart Valves ◽  
Fluid Structure Interaction ◽  
Mechanical Heart Valve ◽  
Immersed Boundary ◽  
Acceleration Phase ◽  
Fluid Structure ◽  
Flow Solver ◽  
Vortical Structures ◽  
Structure Interaction ◽  
Curvilinear Grid

In this work we focus on the fluid-structure interaction (FSI) problem of a St. Jude Regent 23mm bi-leaflet mechanical heart valve (BMHV) implanted in modeled straight aorta geometry with a simplified sinus. A FSI solver based on a recently developed curvilinear grid/immersed boundary method fluid flow solver is developed. The current numerical simulation focuses on the acceleration phase within the cardiac cycle when the leaflets are opening following the incoming flow. The simulated results are compared with experimental data with regard to the leaflet kinematics as well as valve induced wake vortical structures and excellent agreement between the simulation and measurements is reported.

Using Two-Way Fluid-Structure Interaction to Study the Collapse of the Upper Airway of OSA Patients

2014 ◽  
Vol 553 ◽  
pp. 275-280 ◽  
Author(s):  
Mo Yin Zhao ◽  
Tracie J. Barber ◽  
Peter A. Cistulli ◽  
Kate Sutherland ◽  
Gary Rosengarten
Keyword(s):  
Computational Models ◽  
Treatment Success ◽  
Fluid Structure Interaction ◽  
Maximum Velocity ◽  
Upper Airway ◽  
Post Treatment ◽  
Mandibular Advancement ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Obstructive Sleep

Obstructive Sleep Apnea (OSA) is a common sleep disorder characterized by repetitive collapse of the upper airway (UA) during sleep. Treatment options for OSA include mandibular advancement splints (MAS), worn intra-orally to protrude the lower jaw to stabilize the airway. However not all patients will respond to MAS therapy and individual effects on the upper airway are not well understood. Simulations of airway behavior represent a non-invasive means to understand this disorder and treatment responses in individual patients. The aims of this study was to perform analysis of upper airway (UA) occlusion and flow dynamics in OSA using the fluid structure interaction (FSI) method, and secondly to observe changes associated with MAS usage. Magnetic resonance imaging (MRI) scans were obtained with and without mandibular advance splint (MAS) treatment in a patient known to be a treatment responder. Computational models of the anatomically correct UA geometry were reconstructed for both pre-and post-treatment (MAS) conditions. By comparing the simulation results, the treatment success of MAS was demonstrated by smaller UA structure deformation (maximum 2mm) post-treatment relative to the pre-treatment fully collapsed (maximum 6mm) counterpart. The UA collapse was located at the oropharynx and the low oropharyngeal pressure (-51 Pa to-39 Pa) was induced by the velopharyngeal jet flow (maximum 10 m/s). The results support previous OSA computational fluid dynamics (CFD) studies by indicating similar UA pressure drop and maximum velocity values. These findings lay a firm platform for the application of computational models for the study of the biomechanical properties of the upper airway in the pathogenesis and treatment of OSA.

Sign in / Sign up

Export Citation Format

Share Document