title: High-frequency operation of a pulsatile VAD - a simulation study.
abstract: Ventricular assist devices (VADs) are mechanical blood pumps that are clinically used to treat severe heart failure. Pulsatile VADs (pVADs) were initially used, but are today in most cases replaced by turbodynamic VADs (tVADs). The major concern with the pVADs is their size, which prohibits full pump body implantation for a majority of patients. A reduction of the necessary stroke volume can be achieved by increasing the stroke frequency, while maintaining the same level of support capability. This reduction in stroke volume in turn offers the possibility to reduce the pump's overall dimensions. We simulated a human cardiovascular system (CVS) supported by a pVAD with three different stroke rates that were equal, two- or threefold the heart rate (HR). The pVAD was additionally synchronized to the HR for better control over the hemodynamics and the ventricular unloading. The simulation results with a HR of 90 bpm showed that a pVAD stroke volume can be reduced by 71%, while maintaining an aortic pulse pressure (PP) of 30 mm Hg, avoiding suction events, reducing the ventricular stroke work (SW) and allowing the aortic valve to open. A reduction by 67% offers the additional possibility to tune the interaction between the pVAD and the CVS. These findings allow a major reduction of the pVAD's body size, while allowing the physician to tune the pVAD according to the patient's needs.
authors: pd|z Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich.
authors: Mathias
authors: M
authors: Rebholz
authors: Wyss Translational Center Zurich, ETH Zurich, 8092 Zurich.
authors: Raffael
authors: R
authors: Amacher
authors: pd|z Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich.
authors: Anastasios
authors: A
authors: Petrou
authors: pd|z Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich.
authors: Mirko
authors: M
authors: Meboldt
authors: pd|z Product Development Group Zurich, CLA G21.1 Tannenstr. 3, 8092 Zurich.
authors: Marianne
authors: M
authors: Schmid Daners
mesh_terms: D003198:Computer Simulation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D025461:Feedback, Physiological; D006321:Heart / Q000503:physiopathology*; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D006353:Heart-Assist Devices; D006801:Humans; D008955:Models, Cardiovascular; D011673:Pulsatile Flow; D013813:Therapy, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome
keywords: hemodynamics with mechanical circulatory support; pulsatile blood pumps; pulsatility; synchronous operation, ventricular assist device (VAD)