title: An in vitro test bench reproducing coronary blood flow signals.
abstract: BACKGROUND
  It is a known fact that blood flow pattern and more specifically the pulsatile time variation of shear stress on the vascular wall play a key role in atherogenesis. The paper presents the conception, the building and the control of a new in vitro test bench that mimics the pulsatile flows behavior based on in vivo measurements.
  
  
  METHODS
  An in vitro cardiovascular simulator is alimented with in vivo constraints upstream and provided with further post-processing analysis downstream in order to mimic the pulsatile in vivo blood flow quantities. This real-time controlled system is designed to perform real pulsatile in vivo blood flow signals to study endothelial cells' behavior under near physiological environment. The system is based on an internal model controller and a proportional-integral controller that controls a linear motor with customized piston pump, two proportional-integral controllers that control the mean flow rate and temperature of the medium. This configuration enables to mimic any resulting blood flow rate patterns between 40 and 700 ml/min. In order to feed the system with reliable periodic flow quantities in vivo measurements were performed. Data from five patients (1 female, 4 males; ages 44-63) were filtered and post-processed using the Newtonian Womersley's solution. These resulting flow signals were compared with 2D axisymmetric, numerical simulation using a Carreau non-Newtonian model to validate the approximation of a Newtonian behavior.
  
  
  RESULTS
  This in vitro test bench reproduces the measured flow rate time evolution and the complexity of in vivo hemodynamic signals within the accuracy of the relative error below 5%.
  
  
  CONCLUSIONS
  This post-processing method is compatible with any real complex in vivo signal and demonstrates the heterogeneity of pulsatile patterns in coronary arteries among of different patients. The comparison between analytical and numerical solution demonstrate the fair quality of the Newtonian Womersley's approximation. Therefore, Womersley's solution was used to calculate input flow rate for the in vitro test bench.
authors.affiliation: Laboratoire de Médecine Expérimentale (ULB 222 Unit), Route de Gozée 706, 6110, Montigny-Le-Tilleul, Belgium. kamil.chodzynski@umons.ac.be.|Faculté Polytechnique de Mons, Service Fluides-Machines, Université de Mons, 53, rue du Joncquois, 7000, Mons, Belgium. kamil.chodzynski@umons.ac.be.
authors.forename: Kamil Jerzy
authors.initials: KJ
authors.lastname: Chodzyński
authors.affiliation: Laboratoire de Médecine Expérimentale (ULB 222 Unit), Route de Gozée 706, 6110, Montigny-Le-Tilleul, Belgium. kzouaoui@ulb.ac.be.
authors.forename: Karim Zouaoui
authors.initials: KZ
authors.lastname: Boudjeltia
authors.affiliation: Service of Cardiology, CHU Charleroi, Boulevard Zoé Drion 1, 6000, Charleroi, Belgium. Jacques.Lalmand@chu-charleroi.be.
authors.forename: Jacques
authors.initials: J
authors.lastname: Lalmand
authors.affiliation: Service of Cardiology, CHU Charleroi, Boulevard Zoé Drion 1, 6000, Charleroi, Belgium. Adel.Aminian@chu-charleroi.be.
authors.forename: Adel
authors.initials: A
authors.lastname: Aminian
authors.affiliation: Laboratory of Molecular Parasitology, IBMM, Université Libre de Bruxelles (ULB), 12 rue des Prof. Jeener et. Brachet, 6041, Gosselies, Belgium. Luc.Vanhamme@ulb.ac.be.
authors.forename: Luc
authors.initials: L
authors.lastname: Vanhamme
authors.affiliation: Laboratoire de Médecine Expérimentale (ULB 222 Unit), Route de Gozée 706, 6110, Montigny-Le-Tilleul, Belgium. dribeiro@ulb.ac.be.
authors.forename: Daniel Ribeiro
authors.initials: DR
authors.lastname: de Sousa
authors.affiliation: Faculté Polytechnique de Mons, Service Fluides-Machines, Université de Mons, 53, rue du Joncquois, 7000, Mons, Belgium. Simone.Gremmo@umons.ac.be.
authors.forename: Simone
authors.initials: S
authors.lastname: Gremmo
authors.affiliation: Faculté Polytechnique de Mons, Service Fluides-Machines, Université de Mons, 53, rue du Joncquois, 7000, Mons, Belgium. Laurent.Bricteux@umons.ac.be.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bricteux
authors.affiliation: Automatic Control Department, University of Mons, 31, Boulevard Dolez, 7000, Mons, Belgium. Christine.Renotte@umons.ac.be.
authors.forename: Christine
authors.initials: C
authors.lastname: Renotte
authors.affiliation: CREATIS, CNRS UMR 5220, INSERM U1044, UCB Lyon1, INSA Lyon, University of Lyon, 7 Av. Jean Capelle Building Blaise Pascal, 69621, Villeurbanne Cedex, France. guy.courbebaisse@insa-lyon.fr.
authors.forename: Guy
authors.initials: G
authors.lastname: Courbebaisse
authors.affiliation: Faculté Polytechnique de Mons, Service Fluides-Machines, Université de Mons, 53, rue du Joncquois, 7000, Mons, Belgium. Gregory.Coussement@umons.ac.be.
authors.forename: Grégory
authors.initials: G
authors.lastname: Coussement
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D057446:Hydrodynamics; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011673:Pulsatile Flow; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D014057:Tomography, X-Ray Computed