title: A sliding mode-based starling-like controller for implantable rotary blood pumps.
abstract: Clinically adequate implementation of physiological control of a rotary left ventricular assist device requires a sophisticated technique such as the recently proposed method based on the Frank-Starling mechanism. In this mechanism, the stroke volume of the heart increases in response to an increase in the volume of blood filling the left ventricle at the end of diastole. To emulate this process, changes in pump speed need to automatically regulate pump flow to ensure that the combined output of the left ventricle and pump match the output of the right ventricle across changing cardiovascular states. In this approach, we exploit the linear relationship between estimated mean pump flow (Q ̅ est) and pump flow pulsatility (PIQp) in a tracking control algorithm based on sliding mode control. The immediate response of the controller was assessed using a lumped parameter model of the cardiovascular system (CVS) and pump from which could be extracted both Q ̅ est and PIQp. Two different perturbations from the resting state in the presence of left ventricular failure were tested. The first was blood loss requiring a reduction in pump flow to match the reduced output from the right ventricle and to avoid the complication of ventricular suction. The second was exercise, requiring an increase in pump flow. The sliding mode controller induced the required changes in Qp within approximately five heart beats in the blood loss simulation and eight heart beats in the exercise simulation without clinically significant transients or steady-state errors.
authors.affiliation: School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Mohsen A
authors.initials: MA
authors.lastname: Bakouri
authors.forename: Robert F
authors.initials: RF
authors.lastname: Salamonsen
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Savkin
authors.forename: Abdul-Hakeem H
authors.initials: AH
authors.lastname: AlOmari
authors.forename: Einly
authors.initials: E
authors.lastname: Lim
authors.forename: Nigel H
authors.initials: NH
authors.lastname: Lovell
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006333:Heart Failure / Q000503:physiopathology / Q000601:surgery / Q000628:therapy*; D006352:Heart Ventricles / Q000503:physiopathology; D006353:Heart-Assist Devices; D006801:Humans; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D011673:Pulsatile Flow; D016277:Ventricular Function, Left
keywords: Heart failure; Left ventricular assist device; Sliding mode control; Starling-like controller