University College Dublin School of Electrical, Electronics and Mechanical Engineering Belfield, Dublin 4 Ireland Email: [email protected]. Fluid-Structure Interaction (FSI) in Bioengineering V. Kanyanta , N. Quinn, S. Kelly, A. Ivankovic, A. Karac 2 nd OpenFOAM Workshop
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University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Fluid-Structure Interaction (FSI) in Bioengineering
V. Kanyanta, N. Quinn, S. Kelly, A. Ivankovic, A. Karac
2nd OpenFOAM Workshop
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Introduction
• Bioengineering mostly involves the study of the response of biological systems to mechanical loading or stimulus
• E.g Cardiovascular diseases where hemodynamic forces i.e. wall shear stress are known to play a key role in Atherosclerosis
• Numerical studies have become key to understanding the role of hemodynamic forces in cardiovascular diseases
• Most importantly – interaction between flowing blood and deforming vascular wall – FSI (critical)
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
• This presentation looks at 3 applications of FSI in Bioengineering – highlights the importance of FSI
2. Towards early diagnosis of Atherosclerosis - Role of WSS
3. Towards early diagnosis of Atherosclerosis - exploring a novel approach to detecting the development of Atherosclerosis plagues by focusing on the artery wall rather than the flow through it
4. Numerical study of an Abdominal Aortic Aneurysm (AAA)
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Towards Early Diagnosis of Atherosclerosis: Role of Wall Shear Stress
A combined Experimental and Numerical Analysis
V. Kanyanta, A. Ivankovic, A. karac
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
V. Kanyanta, N. Quinn, S. Kelly, A. Ivankovic, A. Karac
• Atherosclerosis is the leading cause of death in the developed world
• It involves local accumulation of lipids, calcium and proliferating cells within arterial walls
• Its development has been linked to the dysfunction of the endothelium - known to be caused by low & highly oscillatory WSS
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Objective:Investigate the role of Wall Shear Stress (WSS) in Atherosclerosis while taking into account the flexibility/deformation of arteries.
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Towards Early Diagnosis of Atherosclerosis: A Combined Experimental and Numerical
Approach
Niamh Quinn, Prof A. Ivankovic, A. Karac
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
V. Kanyanta, N. Quinn, S. Kelly, A. Ivankovic, A. Karac
Motivation For Research
• Traditional diagnostic techniques focus on blood flow and can only detect a plaque in the latter stages of the disease
• This novel approach investigates the deformation of diseased arteries
• Mechanical principles are applied to a medical problem in order to develop a diagnostic technique capable of identifying the disease in its early stages
• Establish “Proof Of Principle”
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Hypothesis
“ An emerging plaque, causing a localised increase in arterial wall thickness, has a
measurable effect on the deformation profile of the artery wall”
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
• Finite Volume Solver: OpenFoam-1.2
• Simulation of experiments
• Linear elastic material– E = 4.2MPa, ρ=1000kg/m3, ν=0.4995
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Fluid and solid properties• Fluid properties – Water
– σ = 1000 kg/m3
– μ = 0.001 kg/ms
• Solid properties – Non-linear material, with the properties of polyurethane rubber
Stress-strain curve for Wet Polyurethane Rubber
0
10
20
30
40
50
0 50 100 150 200 250 300 350 400 450 500 550
Strain (%)
Str
ess
(MP
a)
.
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Creation of aneurysm model
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
• Physiologically realistic boundary conditions
• Fluid and solid meshes moving• Arterial wall with non-linear material properties
Inlet velocity profile
-0.05
0
0.05
0.1
0.15
0 0.5 1 1.5 2
Time (s)
Vel
ocity
(m/s
) .
Idealised outlet pressure
10000
12000
14000
16000
18000
0 0.5 1 1.5 2
Time (s)
Pre
ssur
e (P
a)
.
FSI in aneurysm model
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Fluid Flow
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Stress – Model 1
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Stress – Model 2
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Patient based geometry
• Female patient
• 68 years old
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Fluid flow
Flow visualisation results from “Haemodynamics of Abdominal Aortic Aneurysms: A Comparison between Idealised and Patient-Based Models”, James McCullough, PhD thesis, UCD, 2006
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Fluid flow
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Fluid flow
University College DublinSchool of Electrical, Electronics and Mechanical EngineeringBelfield, Dublin 4Ireland Email: [email protected].
Prof. A. Ivankovic Dr. A. Karac
Dr. J. McCulloughDr. M. O’Rourke
J. Adams
Irish Research Council for Science, Engineering and Technology (IRCSET).