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.

Hemodynamic performance of a compact centrifugal left ventricular assist device with fully magnetic levitation under pulsatile operation: An in vitro study

2020 ◽  
Vol 234 (11) ◽  
pp. 1235-1242 ◽  
Author(s):  
Tingting Wu ◽  
Hao Lin ◽  
Yuxin Zhu ◽  
Penghui Huang ◽  
Frank Lin ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Left Ventricular ◽  
Ventricular Assist Devices ◽  
Circulation System ◽  
Third Generation ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Mock Circulation ◽  
Hemodynamic Performance

Long-term using continuous flow ventricular assist devices could trigger complications associated with diminished pulsatility, such as valve insufficiency and gastrointestinal bleeding. One feasible solution is to produce pulsatile flow assist with speed regulation in continuous flow ventricular assist devices. A third-generation blood pump with pulsatile operation control algorithm was first characterized alone under pulsatile mode at various speeds, amplitudes, and waveforms. The pump was then incorporated in a Mock circulation system to evaluate in vitro hemodynamic effects when using continuous and different pulsatile operations. Pulsatility was evaluated by surplus hemodynamic energy. Results showed that pulsatile operations provided sufficient hemodynamic assistance and increased pulsatility of the circulatory system (53% increment), the mean aortic pressure (65% increment), and cardiac output (27% increment). The pulsatility of the system under pulsatile operation support was increased 147% compared with continuous operation support. The hemodynamic performance of pulsatile operations is susceptible to phase shifts, which could be a tacking angle for physiological control optimization. This study found third-generation blood pumps using different pulsatile operations for ventricular assistance promising.

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.

The Evaluation of Leukocytes in Response to the In Vitro Testing of Ventricular Assist Devices

2013 ◽  
pp. n/a-n/a ◽  
Author(s):  
Chris H.H. Chan ◽  
Andrew Hilton ◽  
Graham Foster ◽  
Karl M. Hawkins ◽  
Nafiseh Badiei ◽  
...  
Keyword(s):  
Ventricular Assist Devices ◽  
In Vitro Testing ◽  
Ventricular Assist ◽  
Assist Devices

Efficacy of Combination of N-acetylcysteine, Gentamicin, and Amphotericin B for Prevention of Microbial Colonization of Ventricular Assist Devices

2009 ◽  
Vol 30 (2) ◽  
pp. 190-192 ◽  
Author(s):  
Maria D. Hernandez ◽  
Mohammad D. Mansouri ◽  
Saima Aslam ◽  
Barry Zeluff ◽  
Rabih O. Darouiche
Keyword(s):  
Antimicrobial Activity ◽  
Amphotericin B ◽  
Rabbit Model ◽  
Microbial Colonization ◽  
Ventricular Assist Devices ◽  
Ventricular Assist ◽  
In Vivo Efficacy ◽  
Assist Devices

We assessed the in vitro antimicrobial activity and the in vivo efficacy of dipping ventricular assist devices in a combination of N-acetylcysteine, gentamicin, and amphotericin B (NAC/G/A). Ventricular assist devices dipped in NAC/G/A exhibited broad-spectrum antimicrobial activity in vitro and were less likely than undipped devices to become colonized with Staphylococcus aureus in a rabbit model.

Hydrodynamic response of a VAD with a compliant cannula: results of in vitro tests

1994 ◽  
Vol 17 (12) ◽  
pp. 635-642 ◽  
Author(s):  
J.C. Antoranz ◽  
J.F. Del Cañizo ◽  
M.M. Desco
Keyword(s):  
The Other ◽  
Hydrodynamic Performance ◽  
Ventricular Assist Devices ◽  
In Vitro Tests ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Hydrodynamic Response

We report on comparative in vitro tests of two ventricular assist devices (VAD) one with a rigid input cannula and the other with a collapsible (compliant) inlet cannula. We show how this compliant cannula yields significant improvements in the hydrodynamic performance of the system.

In Vitro Hemocompatibility Evaluation of Modified Rotary Left to Right Ventricular Assist Devices in Pulmonary Flow Conditions

ASAIO Journal ◽  
2019 ◽  
Vol 66 (6) ◽  
pp. 637-644
Author(s):  
Chris Hoi Houng Chan ◽  
Deepika Nandakumar ◽  
Nicoletta Balletti ◽  
Jarod Horobin ◽  
Eric Lee-Jan Wu ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Ventricular Assist Devices ◽  
Flow Conditions ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Pulmonary Flow
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