CVE Research Seminar

The CVE Research Seminar is a forum for scientific exchange in the group of Cardiovascular Engineering of the ARTORG Center. The CVE Research Seminar convenes at least once per month (typically on Thursdays at 16:00 in F502 of the ARTORG building at Murtenstrasse 50). There are invited talks by external speakers, discussions of papers (journal club) as well as internal presentations of research projects. The CVE Research Seminar is open to guests.

Next Event

Development of integrated patient-specific models of the mitral valve and left ventricle

Michael Sacks

Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering

The University of Texas at Austin

10:00-11:00,  November 21, 2019

sitem-insel, Freiburgstrasse 3, 3010 Bern, Room 01.123

 

 

Abstract:

The mitral valve (MV) regulates blood flow into the left ventricle (LV). In situations where the MV fails to fully close the resulting blood regurgitation into the left atrium causes pulmonary congestion, leading to heart failure and/or stroke. There is now agreement that adjunctive procedures are required to treat IMR, yet there is no consensus regarding the best procedure. There is thus an urgent need for quantitative assessments of MV function to better design surgical solutions. We demonstrate state-of-the-art means to produce patient-specific MV computational models to develop quantitatively optimized devices and procedures for MV repair that incorporate LV geometry. Three patients were randomly selected from the Cardiothoracic Surgical Trial Network (CTSN) for this study. We processed real-time 3D echocardiographic (rt-3DE) images for these patients from before and after undergoing the annuloplasty surgery to extract patient-specific leaflet geometries. For each patient, the pre-operative open valve model was converted into a 3D triangulated mesh using Poisson disk resampling and ball pivoting algorithms. The acquired mesh was then morphed to the closed leaflet geometry through a hyperelastic shape-warping technique that enforced the closed leaflet shape through a level-set penalization. The simulation results showed that our modeling approach can be used to reliably predict the closing behavior of the MV following annuloplasty surgery using pre-operative imaging data (Figure 1). In addition, we computed the leaflet deformation fields in the local surface directions which demonstrated the effects of undersized annuloplasty ring on the entire leaflet. Interestingly, the comparison of pre- and post-operative deformation patterns revealed that the circumferential strain and stress decreased significantly in the entire leaflet while radial components of the strain and stress remained mostly the same before and after the annuloplasty repair surgery.  We have also integrated this technique with complete LV to be able to gain insight into the role of LV geometry on the onset and progress of IMR (Figure 1). Simulating the MV response to surgery from clinical imaging data allows for refinements to treatment planning and optimization of repair surgery procedures. To conclude, we present a pipeline that allows for patient-specific modeling of the MV to predict the valvular response to annuloplasty repair with high predictive power. Our framework only relies on the clinically obtainable imaging data prior to the MV repair operation and thus can be extended into a virtual surgery tool that provides surgeons with additional insight into the patient-specific valvular response to different treatment options.

Figure 1: In-vivo human results for the pre- and post-surgical states. Note that the post-surgical states was accurately predicted from the pre-surgical data alone. Current work is focused on integration of the patient-specific MV pipeline into the left ventricle.

Date/Time Speaker Title Location
 21.12.2019
10:00-11:00
Michael Sacks, James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin
Development of integrated patient-specific models of the mitral valve and left ventricle Freiburgstrasse3, 3010 Bern, Room 01.123
 18.12.2018
10:00-11:00

Prof. Marco D. de Tullio, Department of Mechanics, Mathematics and Management, Politecnico di Bari

A fluid-structure interaction approach for the simulation of biological flows. Murtenstrasse 50, 3008 Bern, Floor F, Room F502
23.11.2018 11:15-12:00 Prof. Dr. med. Andreas Harloff, Klinik für Neurologie und Neurophysiologie, Universitätsklinikum Freiburg Charakterisierung der Aorta und des Herzens mittels 4D Fluss MRT – Daten einer Populationsstudie Room «Paradiso» H612, Wirtschaftsgebäude, Inselspital Bern
22.02.2018
16:00-17:00
Mr. Ali Mosayyebi Accumulation of stent encrustations depends on fluid dynamics: In-vitro study on a stent-on-a-chip model  Murtenstrasse 50, 3008 Bern, Floor F, Room F502
23.112017
14:00-15:00
Utku Gülan, Institute of Environmental Engineering, ETH Zürich Assessment of Energy Loss in the Ascending Aorta of Patients with Stenosis Murtenstrasse 50, 3008 Bern, Floor F, Room F502
28.09.2017
16:00-17:00
Dimosthenis Pasadakis, Università della Svizzera Italiana, Lugano  Fluid-Structure Interaction Simulations of the Human Heart Murtenstrasse 50, 3008 Bern, Floor F, Room F502
 08.06.2017
16:00-17:00
Lena Wiegmann, University of Zurich
Blood damage in ventricular assist devices Murtenstrasse 50, 3008 Bern, Floor F, Room F502
01.06.2017
15:30-16:30
Dario De Marinis, Politecnico di Bari Fluid-Structure-Interaction Immersed-Boundary Methods for Multiphysics Murtenstrasse 50, 3008 Bern, Floor F, Room F502
1.12.2016
16:00-17:00
Christoph Brücker, City University London  Strömungsforschung an biomedizinischen Fragestellungen: Ein Überblick  Murtenstrasse 50, 3008 Bern, Floor F, Room F502
13.10.2016
16:00-17:00
Timo Koch, Universität Stuttgart  An embedded multidimensional model for flow and transport processes in vascularized biological tissue  Murtenstrasse 50, 3008 Bern, Floor F, Room F502
12.09.2016
17:15-18:00
Marcel Filoche, Ecole Polytechnique, Paris 
Fluid transport and surfactant delivery into the lung airway system 
Inselspital, Polikliniktrakt 2 Kursraum D 517
10.06.2016
16:00-17:00
Marco Castagna, Politecnico di Milano A mock circulation loop for the right heart
Murtenstrasse 50, 3008 Bern, Floor F, Room F502
19.05.2016
16:00-17:00 
Alberto Mantegazza, Politecnico di Milano Finite element computational model for the design of a polymeric tracheal stent implantable in biological prosthesis
Murtenstrasse 50, 3008 Bern, Floor A, Room A008
28.04.2016
15:00-16:00
Gian-Reto Nussbaumer, ARTORG Center, University of Bern Minimally invasive measurement of flow rate and blood pressure in the portal vein with an inflatable cuff Murtenstrasse 50, 3008 Bern, Floor A, Room A008
21.04.2016
16:00-17:00
Lino Widmer, ARTORG Center, University of Bern Blood flow measurement in the cerebral microcirculation with the double-circle method  Murtenstrasse 50, 3008 Bern, Floor F, Room F502