Life Sciences Applications: Modeling and Simulation for Biomedical Device Design Kristian.Debus@cd-adapco.com SGC 2013
Mode deling and S and Simu mulatio ion f for Biomed medical De Device Desig e Design • Biomedical device design and the regulatory agencies • Modeling capabilities for the design of various devices • Respiratory • Medical equipment • Cardiovascular • Fluid Structure Interaction (FSI): implicit coupling of STAR-CCM+ and Abaqus
Med edic ical De Devic ice Ap e Appl plicatio ion R Rang ange Diagnostics Macro Devices – MRI/CT Scanners – Stents – Ultrasound – Pumps – Heartvalves Life Support – Artificial Organs – Lung/Heart Machine – Catheters – Dialysis – Pacemakers – Respiratory Aids Monitors – Blood Pressure Micro Devices – ECG, EEG, dissolved gases – Lab on a Chip – Implanted sensors Therapeutic – Implanted drug delivery – Lasers – Infusion Pumps
ASME ME V&V 40 C Com ommit ittee for ormin ing a V&V c V&V commi mmittee t that hat i is appl plication-specif cific t ic to t o the m medical dical device ice indus ind ustry Some E Example Cas ases: : – FDA CPI I – Nozzle – Hemolysis Modeling – Drug delivery to the eye, by intravitreal injection – Oscillatory Pipe Flow – Flow in a Flexible Pipe – CFD Challenge – Aneurysms – Porous media modeling (Fiber bundles) – Oxygenator – Particle tracking etc. etc…..
In Inha haler Mod Modeli ling at t ARUP STA TAR-CC CCM+ + at t VI VIASYS (Car arefusio ion) Healt lthcare re
Mout uth Ca Cavity – Inhalat atio ion Model del Mouth Cavity
Sim implewar are lung dem demo ca case Simpleware was used to obtain the complex geometry from MRI of the human body
Mi Microfluidi dics Formation of droplet in flow-focusing geometry 8
Hea eat Tran ansf sfer, Elect ctronics cs Coolin ing & Noise ise Model dellin ing Ventilation flow and convective cooling as required for MRI/CT scanners, ICU devices Surface wrapping utilized to automatically prepare surface • Volumetric heat sources • Multiple fan models with fan curves •
Workflow: Meshing of Patient Specific Data Surface Wrapping, STL Cleanup & Polyhedral Meshing Rapid Turnaround of Complex Geometry AAA (Abdominal Aortic Aneurysm) Geometry Provided by Computational Clinical Modeling, New Jersey (Chris Ebeling) Dissected Aorta Polyhedral Mesh, Geometry Provided by the Methodist DeBakey Heart and Vascular Center, Houston (Dr. Christof Karmonik, Dr. Mark Davies, Dr. Alan Lumsden, Dr. Jean Bismuth)
Model del s setup Car ardio diovas ascul cular ar flow w wave form from om ap applie ied at at the in inlet Materi rial pr properties of bl f blood ( (Newtonian A Appr pproxima mation) » Density = 1056 kg m -3 » Dynamic Viscosity = 0.0035 Pas R R C 3 C 2 2 3 Win indkes essel p par aram ameters t to o de define ine t the ou outlet cond condit itio ion: n: C Z Z 1 2 R 3 » Z = 1.1x10 7 [kg m -4 s -1 ] 1 Z 1 » R = 1.45x10 8 [kg m -4 s -1 ] » C = 1.45x10 -8 [m 4 s 2 kg -1 ] Lami minar r fl flow mo model • Implicit Unsteady model (dt = 0.001 s) • Coupled implicit solver Z Sim imul ulat atio ion w was r run un for a a nu number of of cy cycl cles t to e o ensure a C 4 4 R per erio iod r respons onse w was ach achie ieved. 4
Pre reli liminary Result ults Anal nalyt ytical ical s sol olut utio ion [ n [2] Analytical Solution • Maximum outlet pressure = 93mmHg. Num umerical ical s solut utio ion n • Maximum outlet pressure = 92.2 mmHg [2] Brown A. G., Patient-Specific Local and Systemic Haemodynamics in the Presence of a Left Ventricular Assist Device , 2012. PhD Thesis, The University of Sheffield.
Flu luid S Structure I Interaction • Driven by highly compliant vessels and membranes, structurally impacted by mechanical devices. • STAR-CCM+ couples directly to Abaqus (Simulia) through a co-simulation API fully coupled, implicit cit , two-way FSI Examples include: Blood Pumps (LVADs), Vena Cava Filter, Stents, Graft Bypass, Diagnostics for Arterial Flows or Lung Models etc. etc.
Coun unter r Intu ntuit itiv ive: Pu Pulse thr through an an Extr treme mely y Flexib Fl xible T Tube Pressure pulse in fluid travels only at a • speed of near 50 m/s when bulk modulus of the solid is 0.1GPa. For completely rigid pipe: pulse would • travel at sound speed of the fluid (1500 m/s). Kinetic energy is primarily being converted • into radial strain energy in the solid when it travels there is nothing left to push the pulse down the pipe. The step size is chosen so that for the • expect wave speed, the wave travels one cell down the axis. So the smaller the modulus, the smaller the wave speed, the larger the time step yet still accurate and stable!! Damon Afkari, Universidad Politécnica de Madrid
FS FSI Simu imulat ation of n of Pu Pulsat atil ile Bl Bloo ood Fl Flow in in Aor ortic Ar Arch ch: Co Coupli pling g Abaq aqus and and STAR-CC CCM+ Universidad Politécnica de Madrid, Damon Afkari: PhD Student Developed Proprietary Explicit Coupling Methodology • Now Implicit Coupling with Aortic Dis ic Dissect ctio ion Abaqus • Focus on Fast Turn Around to Aid Surgeon Decision Making
FSI SI for or H Hea eart t Valve B Biom omech chanics ( University of Connecticut, Prof. Wei Sun, Dr. Eric Sirois) CA CAD
CF CFD Meshi D Meshing & g & Mo Morphi hing ng Valve L Leafl aflet • Poly lyhedra ral l mesh 0.43 mm base size – • Leafle let motion on -> Star ar-CC CCM+ + morph phin ing Separate motion for each leaflet – Interpolated and mapped – • Ar Arbit itrar ary Lagran angian ian-Eule leri rian (A (ALE LE) mesh esh morphin ing • Auto tomated r re-meshing for low w qual uality or zero-volum olume cells “Minimum points in a gap” of 4 nodes – used to control proximity Cr Cros oss-section of CFD CFD Mesh varied from ~700k to 1.8M mo model el showi owing ng po polyhedral – me mesh.
Leaflet Leaf et Mot otion on Com ompar parison FE FEA FE FEA 1 st st Ru 2 nd nd Ru Run Run Lea eaflet Lea eaflet Expe periment nt Mo Motion Mo Motion CFD CF D CFD CF D 1 st st Ru 2 nd nd Ru Run Fa Far-Fi Field Run Pressure Hem emody odynam namics Com ompar parison on
CFD FD V Veloc locity Ma ty Magn gnitu tude a and W WSS Sid ide v e vie iew Top vi view Bottom v vie iew WSS
Heart Valve FSI: Edwards LifeSciences FSI & Overset Meshes Biomedical FSI Applications • Stent Implants: AAA, Coronary, Carotid Arteries etc. • Vena Cava Filters • Heart Valves • Graft Bypass • Aneurysm Diagnostics Models • Respiratory/Lung Models
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