Particle Image Velocimetry Tests on Pediatric 45-cc and 30-cc Ventricle Assist Devices: Effects of Heart Rate on VAD Operation

Witkowski, Dariusz; Obidowski, D.; Reorowicz, P.; Jodko, D.; Jóźwik, Krzysztof

doi:10.5301/ijao.5000618

Cited by 5 publications

(11 citation statements)

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“…Optical techniques, such as particle image velocimetry and laser Doppler anemometry, can be used to measure velocity fields. [11][12][13][14] From the velocity field, estimates of local residence times can be produced. To obtain the total residence time within a VAD, it would be necessary to integrate the velocity field, for example, using pathlines from the inlet to the outlet.…”

Section: Introductionmentioning

confidence: 99%

Experimental measurement and numerical modelling of dye washout for investigation of blood residence time in ventricular assist devices

et al. 2018

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Ventricular assist devices have become the standard therapy for end-stage heart failure. However, their use is still associated with severe adverse events related to the damage done to the blood by fluid dynamic stresses. This damage relates to both the stress magnitude and the length of time the blood is exposed to that stress. We created a dye washout technique which combines experimental and numerical approaches to measure the washout times of ventricular assist devices. The technique was used to investigate washout characteristics of three commercially available and clinically used ventricular assist devices: the CentriMag, HVAD and HeartMate II. The time taken to reach 5% dye concentration at the outlet (T05) was used as an indicator of the total residence time. At a typical level of cardiac support, 5 L/min and 100 mmHg, T05 was 0.93, 0.28 and 0.16 s for CentriMag, HVAD and HeartMate II, respectively, and increased to 5.06, 1.64 and 0.96 s for reduced cardiac support of 1 L/min. Regional variations in washout characteristics are described in this article. While the volume of the flow domain plays a large role in the differences in T05 between the ventricular assist devices, after standardising for ventricular assist device volume, the secondary flow path was found to increase T05 by 35%. The results explain quantitatively, for the first time, why the CentriMag, which exerts low shear stress magnitude, has still been found to cause acquired von Willebrand Syndrome in patients.

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Section: Introductionmentioning

confidence: 99%

Experimental measurement and numerical modelling of dye washout for investigation of blood residence time in ventricular assist devices

et al. 2018

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“…The stagnation area with respect to the total measurement plane (red contour line) was 1.13% during diastole and 0.46% during systole. 19 …”

Section: Resultsmentioning

confidence: 99%

“…A 40% aqueous glycerin solution of the density 1045 kg/m 3 and viscosity 0.0035 Pa s was used as the flow medium to simulate blood parameters. 19 , 26 , 27 The temperature during the tests was 22°C and was constant to maintain the density and viscosity of the solution. The measurements of the velocity fields inside the VAD were made with particle image velocimetry (PIV) conducted with a LaVision FlowMaster system.…”

Section: Methodsmentioning

confidence: 99%

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Methods for determination of stagnation in pneumatic ventricular assist devices

et al. 2018

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Background:A pneumatic paediatric ventricular assist device developed at the Foundation of Cardiac Surgery Development, Zabrze, equipped with valves based on J. Moll’s design, with later modifications introduced at the Institute of Turbomachinery, Lodz University of Technology, was tested numerically and experimentally. The main aim of those investigations was to detect stagnation zones within the ventricular assist device and indicate advantages and limitations of both approaches.Methods:In the numerical transient test, a motion of the diaphragm and discs was simulated. Two different methods were used to illustrate stagnation zones in the ventricular assist device. The flow pattern inside the chamber was represented by velocity contours and vectors to validate the results using images obtained in the laser particle image velocimetry experiment.Results:The experimental light-based method implied problems with proper illumination of regions in the wall vicinity. High-resolution flow data and other important parameters as stagnation regions or flow patterns in regions not accessible for light in the particle image velocimetry method are derived in the numerical solution. However, computations of a single case are much more time-consuming if compared to a single experiment conducted on a well-calibrated stand.Conclusion:The resulting main vortexes in the central part of the pump chamber and the velocity magnitudes are correlated in both methods, which are complementary and when used together offer better insight into the flow structure inside the ventricular assist device and enable a deeper analysis of the results.

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“…However, for long-term applications, implantable biomaterials need to demonstrate the lack of inflammatory response in living tissues. Biomaterial implantology has been used, among others, in the development of glucose biosensors, heart valves and pacemakers, and stents and catheters [ 11 ]. Any foreign material introduced into the body may cause adverse reactions in the form of acute or chronic inflammation, granulation, or fibrosis.…”

Section: Introductionmentioning

confidence: 99%

In Vivo Biocompatibility of an Innovative Elastomer for Heart Assist Devices

et al. 2022

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Cardiac surgical approaches require the development of new materials regardless of the polyurethanes used for pulsatile blood pumps; therefore, an innovative biomaterial, a copolymer of poly(ethylene terephthalate) and dimer fatty acid (dilinoleic acid) modified with D-glucitol, hereafter referred to as PET/DLA, has been developed, showing non-hemolytic and atrombogenic properties and resistance to biodegradation. The aim of this work was to evaluate in vivo inflammatory responses to intramuscular implantation of PET/DLA biomaterials of different compositions (hard to soft segments). Two copolymers containing 70 and 65 wt.% of hard segments, as in poly(ethylene terephthalate) and dilinoleic acid in soft segments modified with D-glucitol, were used for implantation tests to monitor tissue response. Medical grade polyurethanes Bionate II 90A and Bionate II 55 were used as reference materials. After euthanasia of animals (New Zealand White rabbits, n = 49), internal organs and tissues that contacted the material were collected for histopathological examination. The following parameters were determined: peripheral blood count, blood smear with May Grunwald–Giemsa staining, and serum C-reactive protein (CRPP). The healing process observed at the implantation site of the new materials after 12 weeks indicated normal progressive collagenization of the scar, with an indication of the inflammatory–resorptive process. The analysis of the chemical structure of explants 12 weeks after implantation showed good stability of the tested copolymers in contact with living tissues. Overall, the obtained results indicate great potential for PET/DLA in medical applications; however, final verification of its applicability as a structural material in prostheses is needed.

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Particle Image Velocimetry Tests on Pediatric 45-cc and 30-cc Ventricle Assist Devices: Effects of Heart Rate on VAD Operation

Cited by 5 publications

References 11 publications

Experimental measurement and numerical modelling of dye washout for investigation of blood residence time in ventricular assist devices

Experimental measurement and numerical modelling of dye washout for investigation of blood residence time in ventricular assist devices

Methods for determination of stagnation in pneumatic ventricular assist devices

In Vivo Biocompatibility of an Innovative Elastomer for Heart Assist Devices

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