title: Numerical optimization studies of cardiovascular-rotary blood pump interaction.
abstract: A heart-pump interaction model has been developed based on animal experimental measurements obtained with a rotary blood pump in situ. Five canine experiments were performed to investigate the interaction between the cardiovascular system and the implantable rotary blood pump over a wide range of operating conditions, including variations in cardiac contractility and heart rate, systemic vascular resistance (SVR), and total blood volume (V(total) ). It was observed in our experiments that SVR decreased with increasing mean pump speed under the healthy condition, but was relatively constant during the speed ramp study under reduced cardiac contractility conditions. Furthermore, we also found a significant increase in pulmonary vascular resistance with increasing mean pump speed and decreasing total blood volume, despite a relatively constant SVR. Least squares parameter estimation methods were utilized to fit a subset of model parameters in order to achieve better agreement with the experimental data and to evaluate the robustness and validity of the model under various operating conditions. The fitted model produced reasonable agreement with the experimental measurements, both in terms of mean values and steady-state waveforms. In addition, all the optimized parameters were within physiological limits.
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia. einly_lim@um.edu.my
authors.forename: Einly
authors.initials: E
authors.lastname: Lim
authors.forename: Socrates
authors.initials: S
authors.lastname: Dokos
authors.forename: Robert F
authors.initials: RF
authors.lastname: Salamonsen
authors.forename: Franklin L
authors.initials: FL
authors.lastname: Rosenfeldt
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Ayre
authors.forename: Nigel H
authors.initials: NH
authors.lastname: Lovell
mesh_terms: D058646:Adrenergic alpha-1 Receptor Agonists / Q000494:pharmacology; D058671:Adrenergic beta-1 Receptor Antagonists / Q000494:pharmacology; D000818:Animals; D001810:Blood Volume; D004285:Dogs; D006333:Heart Failure / Q000628:therapy; D006339:Heart Rate; D006353:Heart-Assist Devices; D006801:Humans; D016018:Least-Squares Analysis; D008680:Metaraminol / Q000494:pharmacology; D008790:Metoprolol / Q000494:pharmacology; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D009599:Nitroprusside / Q000494:pharmacology; D010952:Plasma Substitutes; D011097:Polygeline; D014655:Vascular Resistance; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D058646:Adrenergic alpha-1 Receptor Agonists; D058671:Adrenergic beta-1 Receptor Antagonists; D010952:Plasma Substitutes; D014665:Vasodilator Agents; D009599:Nitroprusside; D008680:Metaraminol; D011097:Polygeline; D008790:Metoprolol