TY - GEN A1 - Behbahani, Mehdi A1 - Mai, A. A1 - Waluga, C. A1 - Bergmann, B. A1 - Tran, L. A1 - Vonderstein, K. A1 - Behr, Marek A1 - Mottaghy, K. T1 - Numerical Modeling of Flow-Related Thrombus Formation under Physiological and Non-Physiological Flow Conditions T2 - Acta Physiologica N2 - Aims: Thrombotic complications due to activation of platelets and plasmatic clotting factors belong still to the most investigated topics in the field of study of patho-physiological mechanisms. Mathematical modeling of thrombotic reactions is established and validated in test cases. Aim of this study is to experimentally evaluate and computationally simulate platelets under the influence of well-defined shear flow conditions. Platelet behaviour and reactions are experimentally reproduced, measured and used for validation of the numerical simulation. Methods: A mathematical model of platelet activation, adhesion and aggregation has been implemented into a finite element CFD (Computational Fluid Dynamics) code. The approach is based on the advective and diffusive transport equations for resting platelets, activated platelets and platelet released agonists. Adhesion rates for the reactive surfaces depend on the hemocompatibility properties of the surface and the local shear rate. Experiments with citrate-anticoagulated freshly-drawn whole blood are performed in a perfusion flow chamber as well as in a system of rotating cylinders for Couette and Taylor-vortex flow. Different biomaterials are used. The activation, drop of platelet concentration, adhesion and aggregation are quantified using scanning electron microscopy (SEM) and flow cytometry. Results: Regions and flow conditions with a high potential for thrombus growth could be identified. The experiments clearly show the influence of the blood contacting material and flow properties. By means of SEM diverse platelet adhesion patterns are observed. Numerical analysis can explain the patterns and the degree of thrombus formation. Conclusion: The numerical method shows good agreement with experimental data indicating a possible prediction of initiation of activation and detection of the local adhesion areas in connection with the role of Von-Willebrand-Factor. Y1 - 2010 SN - 1748-1716 N1 - Joint Congress of the Scandinavian and German Physiological Societies, Copenhagen, Denmark, March 27-30, 2010 VL - 198 IS - Supplement 677 SP - 185 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Probst, M. A1 - Mai, A. A1 - Behr, Marek A1 - Tran, L. A1 - Vonderstein, K. A1 - Mottaghy, K. T1 - Numerical Prediction of Blood Damage in Biomedical Devices Y1 - 2010 N1 - Biomedica: The Life Science Summit, Aachen, Germany , 2010-03-17 - 2010-03-18 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Probst, M. A1 - Mai, A. A1 - Tran, L. A1 - Vonderstein, K. A1 - Keschenau, P. A1 - Linde, T. A1 - Steinseifer, U. A1 - Behr, Marek A1 - Mottaghy, K. T1 - The influence of high shear on thrombosis and hemolysis in artificial organs JF - The International Journal of Artificial Organs Y1 - 2010 SN - 0391-3988 VL - 33 IS - 7 SP - 426 EP - 426 PB - Sage CY - Thousand Oaks ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Mai, A. A1 - Bergmann, B. A1 - Waluga, C. A1 - Behr, Marek A1 - Tran, L. A1 - Vonderstein, K. A1 - Mottaghy, K. T1 - Modeling and Numerical Simulation of Blood Damage Y1 - 2010 N1 - Posterpresentation ; Umbrella Symposium "Modelling and Simulation in Medicine, Engineering and Sciences", Forschungszentrum Jülich, January 18-20, 2010 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Waluga, C. A1 - Stock, S. A1 - Mai, A. A1 - Bergmann, B. A1 - Behr, Marek A1 - Tran, L. A1 - Vonderstein, K. A1 - Scheidt, H. A1 - Oedekoven, B. A1 - Mottaghy, K. T1 - Modelling and Numerical Analysis of Platelet Reactions and Surface Thrombus Growth Y1 - 2009 N1 - Posterpresentation ; European Society of Biomaterials (ESB), Lausanne, Switzerland, September 7-10, 2009 ER - TY - JOUR A1 - Tran, Linda A1 - Mottaghy, K. A1 - Arlt-Körfer, Sabine A1 - Waluga, Christian A1 - Behbahani, Mehdi T1 - An experimental study of shear-dependent human platelet adhesion and underlying protein-binding mechanisms in a cylindrical Couette system JF - Biomedizinische Technik Y1 - 2017 U6 - https://doi.org/10.1515/bmt-2015-0034 SN - 0013-5585 VL - 62 IS - 4 SP - 383 EP - 392 PB - De Gruyter CY - Berlin ER - TY - GEN A1 - Behbahani, Mehdi A1 - Nam, J. A1 - Waluga, C. A1 - Behr, Marek A1 - Pasquali, M. A1 - Mottaghy, K. T1 - Modeling and Numerical Analysis of Platelet Activation, Adhesion and Aggregation in Artificial Organs T2 - ASAIO Journal N2 - Purpose of Study: Thrombosis-related complications are among the leading causes for morbidity and mortality in patients who depend on artificial organs. For the prediction of platelet behavior both the flow conditions inside the device and the thrombogenic properties of the blood-contacting surfaces must be considered. Platelet reactions under the influence of well-defined shear rates are experimentally evaluated and numerically simulated. The approach is intended for the analysis of VAD and oxygenator design. Methods Used: A mathematical model of platelet activation, adhesion and aggregation has been implemented into a finite element CFD (Computational Fluid Dynamics) code. The approach is based on the advective and diffusive transport equations for resting and activated platelets and platelet released agonists. Experiments with citrate-anticoagulated freshly-drawn whole blood are performed in a perfusion flow chamber as well as in a system of rotating cylinders for Couette and Taylor-vortex flow. Different biomaterials are used. The activation, adhesion and aggregation are quantified using scanning electron microscopy and flow cytometry. Summary of Results: Regions and flow conditions with a high potential for thrombus growth could be identified. The experiments clearly show the influence of the blood contacting material and governing shear rates. Numerical analysis can explain observed adhesion patterns and the degree of thrombus formation Y1 - 2010 U6 - https://doi.org/10.1097/01.mat.0000369377.65122.a3 SN - 1538-943X N1 - 56th annual conference, American Society of Artificial Organs (ASAIO), Baltimore, USA, May 27-29, 2010 VL - 56 IS - 2 SP - 85 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Tran, L. A1 - Waluga, C. A1 - Behr, Marek A1 - Oedekoven, B. A1 - Mottaghy, K. T1 - Model-based Numerical Analysis of Platelet Adhesion, Thrombus Growth and Aggregation for Assist Devices JF - The International Journal of Artificial Organs. 32 (2009), H. 7 Y1 - 2009 SN - 0391-3988 N1 - Abstracts - Oral Presentations: XXXVI Annual ESAO Congress, 2-5 September 2009, Compiègne - France; European Society of Artificial Organs (ESAO), Compiegne, France, September 2-5, 2009 SP - 398 EP - 398 ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Tran, L. A1 - Jockenhövel, S. A1 - Behr, Marek A1 - Mottaghy, K. T1 - Numerical prediction of thrombocyte reactions for application to a vascular flow model JF - British Journal of Surgery Y1 - 2011 SN - 1365-2168 N1 - 46th Congress of the European Society for Surgical Research, Aachen, Germany, 25-28 May 2011 ; ESSR Abstracts 2011 ; Oral Sessions OP10-5 VL - 98 IS - S5 SP - S17 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Behbahani, Mehdi A1 - Waluga, C. A1 - Arlt, S. A1 - Behr, Marek A1 - Mottaghy, K. T1 - Computational Analysis of Platelet Aggregation in a Taylor-Couette System JF - The International Journal of Artificial Organs. 31 (2008), H. 7 Y1 - 2008 SN - 0391-3988 N1 - Posterpresentation ; European Society of Artificial Organs (ESAO), Geneva, Switzerland SP - 643 ER -