Pulsatile control of rotary blood pumps: Does the modulation waveform matter?

Pirbodaghi, Tohid; Axiak, Shannon; Weber, Alberto; Gempp, Thomas; Vandenberghe, Stijn

doi:10.1016/j.jtcvs.2012.02.015

Cited by 63 publications

(67 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These differences, however, were negligible compared to the effects of the three pump parameters ϕ, ϕ p and synchronization ratio. These findings agree with the results published by Pirbodaghi et al [26], who investigated different speed modulation patterns for tVADs. In our investigations the intensity of hemodynamic effects attributed to both simulated VADs (pVAD and tVAD) scales with the assist ratio.…”

Section: Discussionsupporting

confidence: 93%

“…The tVAD simulation was intended as a baseline experiment that represents the use of tVADs in clinical application today. There are numerous studies that have investigated augmented pulsatility in tVADs through speed modulation [1,3,4,16,26,27,33,34]. These studies have shown improved levels of pulsatility, left ventricular unloading and blood flow through the aortic valve, but were exceeded by the values of our pVAD simulation.…”

Section: Discussionmentioning

confidence: 92%

“…Previous studies have investigated synchronization ratios (1:2 and 1:4) lower than the HR under one given phase-shift setting [24] with the intention of establishing a weaning protocol. The importance of considering the pump timing and systolic fraction as an integral part of the investigation has been shown in vivo by [2] for pVADs and by [1,3,4,26,33,34] both in silico and in vivo for tVADs.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

High-frequency operation of a pulsatile VAD – a simulation study

Rebholz

Amacher

Petrou

et al. 2017

Biomedical Engineering / Biomedizinische Technik

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

High-frequency operation of a pulsatile VAD – a simulation study

Rebholz

Amacher

Petrou

et al. 2017

Biomedical Engineering / Biomedizinische Technik

View full text Add to dashboard Cite

show abstract

“…Different types of speed profiles, synchronized to the natural cardiac cycle, have been applied in silico and in vitro to analyze their influence on perfusion, pulse pressure and ventricular unloading [13][14][15][16][17][18]. In vivo experiments have been conducted to validate this approach [19,20]. Common among all previous research on this topic was the preselection of a certain speed profile, such as a sine wave or a square wave.…”

Section: Introductionmentioning

confidence: 99%

Numerical Optimal Control of Turbo Dynamic Ventricular Assist Devices

et al. 2013

Self Cite

View full text Add to dashboard Cite

Abstract:The current paper presents a methodology for the derivation of optimal operating strategies for turbo dynamic ventricular assist devices (tVADs). In current clinical practice, tVADs are typically operated at a constant rotational speed, resulting in a blood flow with a low pulsatility. Recent research in the field has aimed at optimizing the interaction between the tVAD and the cardiovascular system by using predefined periodic speed profiles. In the current paper, we avoid the limitation of using predefined profiles by formulating an optimal-control problem based on a mathematical model of the cardiovascular system and the tVAD. The optimal-control problem is solved numerically, leading to cycle-synchronized speed profiles, which are optimal with respect to an arbitrary objective. Here, an adjustable trade-off between the maximization of the flow through the aortic valve and the minimization of the left-ventricular stroke work is chosen. The optimal solutions perform better than constant-speed or sinusoidal-speed profiles for all cases studied. The analysis of optimized solutions provides insight into the optimized Bioengineering 2014, 1 23 interaction between the tVAD and the cardiovascular system. The numerical approach to the optimization of this interaction represents a powerful tool with applications in research related to tVAD control. Furthermore, patient-specific, optimized VAD actuation strategies can potentially be derived from this approach.

show abstract

“…As controversy still remains on this issue, the development of pulsatile rotary blood pumps would provide a unique opportunity for further research and comparison [4][5].…”

mentioning

confidence: 99%