Heart attack prediction via fluid-structure interaction simulation

master's thesis

• Title (croatian): Predviđanje srčanog udara primjenom simulacije međudjelovanja između fluida i deformabilnog tijela
• Author: Josip Ištvanović
• Mentor: Željko Tuković (mentor)
• Mentor: Peter De Jaeger https://orcid.org/0000-0003-3398-6833 (komentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-07-20, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

Cardiovascular diseases are the leading cause of death in modern civilization, which result from insufficient coronary blood flow. The majority of them can be attributed to atherosclerosis, which causes the development of plaques that protrude into the vessel lumens and either block or partially block blood flow. The partial blockage leads to the development of collateral coronary circulation that can eliminate any symptoms of cardiac dysfunction to some degree. When the collateral circulation is insufficient, the heart muscle becomes severely limited in its work output, resulting in a heart attack.
The main focus of this thesis is to simulate the nonlinear dynamics of the atherosclerotic coronary artery as a tool to predict the occurrence of a heart attack. A three-dimensional fluid-structure interaction (FSI) model is reconstructed based on the patient-specific computerized tomography (CT) scans and simulated via the finite volume method using OpenFOAM® for the determination of regions with the highest von Misses and shear stresses. The arterial wall is assumed to be rigid, while the accumulated plaque is modeled as a hyperelastic incompressible body. The fluid model incorporates transient isothermal and laminar blood flow with simplified geometry and realistic hemodynamic conditions, where blood is modeled as a Newtonian and incompressible fluid. The atherosclerotic plaque is modeled as a homogeneous solid body with mixed material properties such as smooth muscle cells, collagen, and lipids. These are the main constituents of the plaque body, all significantly different in their stiffness level, which may be the main cause of plaque rupture and initiation of myocardial infarction.
In the future, the study of arterial blood flow will lead to the prediction of individual hemodynamic flows in any patient, the development of diagnostic tools to quantify the disease, and the design of devices that mimic or alter blood flow. This field is rich in challenging problems in fluid mechanics involving three-dimensional, pulsating flows at the edge of turbulence.

Abstract (croatian)

Bolesti krvožilnog sustava predstavljaju glavni uzrok smrti u suvremeno dobra, a posljedica su nedostatnog koronarnog protoka krvi. Većina ih se može pripisati aterosklerozi koja uzrokuje stvaranje aterosklerotskog plaka, koji strši u lumen krvnih žila i djelomično ili posve priječi protok krvi. Djelomično začepljenje dovodi do razvoja kolateralne koronarne cirkulacije koja u određenoj mjeri može ukloniti simptome srčane disfunkcije. Kada i kolateralna cirkulacija nije dovoljna, sposobnost srčanog mišića za obavljanje rada se značajno smanjuje, što s vremenom dovodi do srčanog udara.
Glavni cilj ovo rada je simulacija nelinearnog ponašanja aterosklerotične koronarne arterije koja može poslužiti kao alat za predviđanje srčanog udara. Trodimenzionalni model međudjelovanja fluida i čvrstog tijela (FSI) rekonstruiran je na temelju CT skenova, specifičnog za pojedinog pacijenta, i simuliran metodom kontrolnih volumena koristeći programski paket OpenFOAM® za određivanje područja s najvećim normalnim i posmičnim naprezanjima. Pretpostavljena je kruta arterijska stijenka, dok je nakupljeni plak modeliran kao hiperelastično nestlačivo tijelo. Model fluida uključuje nestacionarni izotermni i laminarni protok krvi s pojednostavljenom geometrijom i realnim hemodinamičkim uvjetima, dok je krv modelirana kao nestlaičivi i newtonski fluid. Aterosklerotski plak je modeliran kao homogeno čvrsto tijelo s miješanim svojstvima materijala kao što su glatke mišićne stanice, kolagen i lipidi. Oni predstavljaju glavne slojeve plaka, a njihova značajna razlika u krutosti može biti jedan od glavnih uzroka njegova puknuća, a samim time i infarkta miokarda.
U budućnosti će proučavanje arterijskog krvotoka dovesti do predviđanja pojedinačnih hemodinamičkih tokova kod pacijenata, razvoja dijagnostičkih alata za kvantificiranje bolesti i dizajna uređaja koji oponašaju ili mijenjaju protok krvi. Ovo polje je bogato izazovnim problemima u mehanici fluida koji uključuju trodimenzionalne, pulsirajuće tokove na rubu turbulencije.

• Keywords: coronary artery; atherosclerosis; fluid-structure interaction; FSI; OpenFOAM
• Keywords (croatian): koronarne arterije; ateroskleroza; međudjelovanje fluida i deformabilnog tijela; FSI; OpenFOAM
• Language: english
• URN:NBN: urn:nbn:hr:235:701587
• Study programme: Title: Mechanical Engineering; specializations in: Design, Process and Energy Engineering, Production Engineering, Engineering Modelling and Computer Simulation, Marine Engineering, Industrial Engineering and Management, Materials Engineering, Mechatronics and Robotics, Autonomous Systems; Course: Engineering Modelling and Computer Simulation; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2024-07-20
• Created on: 2022-07-13 10:36:52