scholarly journals A Hybrid Mock Circulation for Control Algorithms of Ventricular Assist Devices

2019 ◽  
Vol 5 (1) ◽  
pp. 409-411
Author(s):  
Tobias Salesch ◽  
Jonas Gesenhues ◽  
Dirk Abel
Keyword(s):  
Optimal Control ◽  
Ventricular Assist Devices ◽  
Design Parameters ◽  
Control Algorithms ◽  
Proof Of Concept ◽  
Ventricular Assist ◽  
Test Conditions ◽  
Mock Circulation ◽  
Simulation And Control ◽  
And Control

AbstractThis paper deals with the design, simulation and control of a new lightweight hybrid Mock-Loop (MCL) concept. The proof of concept is evaluated by two simulation approaches. First, the design parameters are chosen by an optimal control problem. Second, a cascading controller structure is evaluated in a simulation. Both show that with a suitable range of the design parameter the new lightweight concept can be used as a MCL. To validate these findings, further investigations with the MCL under realistic test conditions are required.

Left Ventricular Assist Device Evaluation With a Model-Controlled Mock Circulation

2007 ◽  
Author(s):  
Mark Vaes ◽  
Marcel Rutten ◽  
René van de Molengraft ◽  
Frans van de Vosse
Keyword(s):  
Systemic Circulation ◽  
Left Ventricular ◽  
Ventricular Assist Devices ◽  
Left Ventricular Assist Devices ◽  
Bridge To Recovery ◽  
Assist Device ◽  
Ventricular Assist ◽  
Mock Circulation ◽  
Left Ventricular Assist ◽  
And Control

Left-ventricular assist devices (LVADs) have evolved from being a bridge to total heart transplant to forming a bridge to recovery of the heart. With this development, the process of weaning has become more important, and consequently, the operation and control of the LVADs during this process is more important as well. To evaluate the function and the assist properties of LVADs, a mock circulation, featuring the properties of the (diseased) heart and the systemic circulation may prove to be a valuable tool.

scholarly journals Response of a physiological controller for ventricular assist devices during acute patho-physiological events: an in vitro study

2017 ◽  
Vol 62 (6) ◽  
pp. 623-633 ◽  
Author(s):  
Anastasios Petrou ◽  
Panagiotis Pergantis ◽  
Gregor Ochsner ◽  
Raffael Amacher ◽  
Thomas Krabatsch ◽  
...  
Keyword(s):  
Valsalva Maneuver ◽  
Constant Speed ◽  
Ventricular Assist Devices ◽  
Moving Window ◽  
Clinical Implementation ◽  
Premature Ventricular Contractions ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Mock Circulation

AbstractThe current paper analyzes the performance of a physiological controller for turbodynamic ventricular assist devices (tVADs) during acute patho-physiological events. The numerical model of the human blood circulation implemented on our hybrid mock circulation was extended in order to simulate the Valsalva maneuver (VM) and premature ventricular contractions (PVCs). The performance of an end-diastolic volume (EDV)-based physiological controller for VADs, named preload responsive speed (PRS) controller was evaluated under VM and PVCs. A slow and a fast response of the PRS controller were implemented by using a 3 s moving window, and a beat-to-beat method, respectively, to extract the EDV index. The hemodynamics of a pathological circulation, assisted by a tVAD controlled by the PRS controller were analyzed and compared with a constant speed support case. The results show that the PRS controller prevented suction during the VM with both methods, while with constant speed, this was not the case. On the other hand, the pump flow reduction with the PRS controller led to low aortic pressure, while it remained physiological with the constant speed control. Pump backflow was increased when the moving window was used but it avoided sudden undesirable speed changes, which occurred during PVCs with the beat-to-beat method. In a possible clinical implementation of any physiological controller, the desired performance during frequent clinical acute scenarios should be considered.

In vivo proof of concept of a pulsatile physiologic controller framework for ventricular assist devices

2021 ◽  
Author(s):  
Tobias Salesch ◽  
Jonas Gesenhues ◽  
Moriz Habigt ◽  
Mare Mechelinck ◽  
Marc Hein ◽  
...  
Keyword(s):  
Ventricular Assist Devices ◽  
Proof Of Concept ◽  
Ventricular Assist ◽  
Assist Devices

scholarly journals Analysis of Operating Modes for Left Ventricle Assist Devices via Integrated Models of Blood Circulation

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1331 ◽  
Author(s):  
Sergey Simakov ◽  
Alexander Timofeev ◽  
Timur Gamilov ◽  
Philip Kopylov ◽  
Dmitry Telyshev ◽  
...  
Keyword(s):  
Left Ventricular ◽  
Operating Conditions ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Left Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Lumped Model ◽  
Assist Devices ◽  
Operating Modes ◽  
Mock Circulation

Left ventricular assist devices provide circulatory support to patients with end-stage heart failure. The standard operating conditions of the pump imply limitations on the rotation speed of the rotor. In this work we validate a model for three pumps (Sputnik 1, Sputnik 2, Sputnik D) using a mock circulation facility and known data for the pump HeartMate II. We combine this model with a 1D model of haemodynamics in the aorta and a lumped model of the left heart with valves dynamics. The model without pump is validated with known data in normal conditions. Simulations of left ventricular dilated cardiomyopathy show that none of the pumps are capable of reproducing the normal stroke volume in their operating ranges while complying with all criteria of physiologically feasible operation. We also observe that the paediatric pump Sputnik D can operate in the conditions of adult circulation with the same efficiency as the adult LVADs.

scholarly journals Numerical Optimal Control of Turbo Dynamic Ventricular Assist Devices

2013 ◽  
Vol 1 (1) ◽  
pp. 22-46 ◽  
Author(s):  
Raffael Amacher ◽  
Jonas Asprion ◽  
Gregor Ochsner ◽  
Hendrik Tevaearai ◽  
Markus Wilhelm ◽  
...  
Keyword(s):  
Optimal Control ◽  
Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Assist Devices

Discrete-Time H2-Optimal Control for Hydraulic Position Control Systems

2007 ◽  
Author(s):  
Yang Lin ◽  
Yang Shi ◽  
Richard Burton
Keyword(s):  
Optimal Control ◽  
Control Systems ◽  
Discrete Time ◽  
Ad Hoc ◽  
Position Control ◽  
Experimental Studies ◽  
Design Procedure ◽  
Design Parameters ◽  
Practical Applications ◽  
And Control

Hydraulic position control systems play an important role in industrial automation. This paper explores the application of discrete-time H2-optimal control for a hydraulic position control system (HPCS). By minimizing the H2-norm of the system, the discrete-time robust H2-optimal control both stabilizes the plant and minimizes the root-mean-square of the servo position error simultaneously. The intuitive nature of this advanced approach helps to manage the selection of design parameters, whereas, classical methods provide less insight into strategies for parameter selection and control design. Additionally, the powerful ability to address disturbances and uncertainty in the robust H2-optimal design offers a more direct alternative to the ad hoc and iterative nature of classical methods for the hydraulic servo position system. Computer simulations illustrate the design procedure and the effectiveness of the proposed method. Experimental studies which employ the H2-optimal control on a hydraulic positioning system are also conducted and the results show that the method is suitable for practical applications.

A Proof-of-Concept Demonstration for a Novel Soft Ventricular Assist Device

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Saleh H. Gharaie ◽  
Amir Ali Amir Moghadam ◽  
Subhi J. Al'Aref ◽  
Alexandre Caprio ◽  
Seyedhamidreza Alaie ◽  
...  
Keyword(s):  
Soft Materials ◽  
Ventricular Assist Devices ◽  
Proof Of Concept ◽  
Bridge To Recovery ◽  
Bridge To Transplantation ◽  
Assist Device ◽  
Ventricular Assist ◽  
Physiological Flow ◽  
The Common ◽  
Post Implantation

Patients treated by current ventricular assist devices (VADs) suffer from various post implantation complications including gastrointestinal bleeding and arteriovenous malformation. These issues are related to intrinsically mismatch of generated flow by VADs and the physiological flow. In addition, the common primary drawback of available VADs is excessive surgical dissection during implantation, which limits these devices to less morbid patients. We investigated an alternative soft VAD (SVAD) system that generates physiological flow, and designed to be implanted using minimally invasive surgery by leveraging soft materials. A soft VAD (which is an application of intraventricular balloon pump) is developed by utilizing a polyurethane balloon, which generates pulsatile flow by displacing volume within the left ventricle during its inflation and deflation phases. Our results show that the SVAD system generates an average ejection fraction of 50.18 ± 1.52% (n = 6 ± SD) in explanted porcine hearts. Since the SVAD is implanted via the apex of the heart, only a minithoracotomy should be required for implantation. Our results suggest that the SVAD system has the performance characteristics that could potentially make it useful for patients in acute and/or chronic heart failure, thus serving as a bridge-to-transplantation or bridge-to-recovery.

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