Turbulence Measurements in an Axial Rotary Blood Pump with Laser Doppler Velocimetry

2017 ◽  
Vol 40 (3) ◽  
pp. 109-117 ◽  
Author(s):  
Chan Y. Schüle ◽  
Klaus Affeld ◽  
Max Kossatz ◽  
Christian O. Paschereit ◽  
Ulrich Kertzscher
Keyword(s):  
Laser Doppler Velocimetry ◽  
Laser Doppler ◽  
Ventricular Assist Devices ◽  
Blood Pump ◽  
Doppler Velocimetry ◽  
Rotary Blood Pump ◽  
Measured Velocity ◽  
Blood Pumps ◽  
Velocity Spectra ◽  
Rotary Blood Pumps

Background The implantation of rotary blood pumps as ventricular assist devices (VADs) has become a viable therapy for quite a number of patients with end-stage heart failure. However, these rotary blood pumps cause adverse events that are related to blood trauma. It is currently believed that turbulence in the pump flow plays a significant role. But turbulence has not been measured to date because there is no optical access to the flow space in rotary blood pumps because of their opaque casings. Methods This difficulty is overcome with a scaled-up model of the HeartMate II (HM II) rotary blood pump with a transparent acrylic housing. A 2-component laser Doppler velocimetry (LDV) system was used for the measurement of time resolved velocity profiles and velocity spectra upstream and downstream of the rotor blades. Observing similarity laws, the speed and pump head were adjusted to correspond closely to the design point of the original pump – 10,600 rpm speed and 80 mmHg pressure head. A model fluid consisting of a water-glycerol mixture was used. Results The measured velocity spectra were scalable by the Kolmogorov length and the Kolmogorov length was estimated to be between 14 and 24 μm at original scale, thus being about 1.5 to 3 times the size of a red blood cell. Conclusions It can be concluded that turbulence is indeed present in the investigated blood pump and that it can be described by Kolmogorov's theory of turbulence. The size of the smallest vortices compares well to the turbulence length scales as found in prosthetic heart valves, for example.

Preliminary evaluation of a predictive controller for a rotary blood pump based on pulmonary oxygen gas exchange

2019 ◽  
Vol 233 (2) ◽  
pp. 267-278 ◽  
Author(s):  
Feng Huang ◽  
Zhe Gou ◽  
Yang Fu
Keyword(s):  
Gas Exchange ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Left Ventricular ◽  
Blood Pump ◽  
Rotary Blood Pump ◽  
Blood Pumps ◽  
Control Objective ◽  
Predictive Controller ◽  
Rotary Blood Pumps

Physiological control of rotary blood pumps is becoming increasingly necessary for clinical use. In this study, the mean oxygen partial pressure in the upper airway was first quantitatively evaluated as a control objective for a rotary blood pump. A model-free predictive controller was designed based on this control objective. Then, the quantitative evaluation of the controller was implemented with a rotary blood pump model on a complete cardiovascular model incorporated with airway mechanics and gas exchange models. The results show that the controller maintained a mean oxygen partial pressure at a normal and constant level of 138 mmHg in the left heart failure condition and restored basic haemodynamics of blood circulation. A left ventricular contractility recovery condition was also replicated to assess the response of the controller, and a stable result was obtained. This study indicates the potential use of the oxygen partial pressure index during pulmonary gas exchange when developing a multi-objective physiological controller for rotary blood pumps.

Physiology of Continuous-Flow Pumps

2012 ◽  
Vol 23 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Dawn M. Christensen
Keyword(s):  
Continuous Flow ◽  
Blood Pump ◽  
Circulatory Support ◽  
Cardiovascular Physiology ◽  
Rotary Blood Pump ◽  
Monitoring Methods ◽  
Failing Heart ◽  
Blood Pumps ◽  
Rotary Blood Pumps

The use of mechanical pumps for circulatory support started in the mid-1950s. The evolution of these devices has led to the present-day use of continuous-flow pumps to take over the function of a patient’s failing heart. The physiology associated with rotary blood pump use is quite different from normal cardiovascular physiology. Clinicians caring for patients who are supported by rotary blood pumps must have an understanding of the differences in physiology, monitoring methods, and unique complications associated with the use of these pumps.

Experimental Investigation of Water Jet Orifice Efficiency by a Novel Laser Doppler Velocimetry Technique

2006 ◽  
Author(s):  
Massimiliano Annoni ◽  
Loredana Cristaldi ◽  
Michele Norgia ◽  
Cesare Svelto
Keyword(s):  
Laser Doppler Velocimetry ◽  
High Speed ◽  
Dynamic Range ◽  
Water Jet ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Measured Velocity ◽  
Range Resolution ◽  
Cutting Head ◽  
Experimental Trials

The problem of efficiency evaluation of water jet nozzles has been dealt in the present work and a novel Laser Doppler Velocimetry (LDV) technique has been proposed in order to acquire high-speed water velocity at the exit of the cutting head nozzles. A standard LDV technique has been implemented for the first experimental trials with the aim of applying the theoretical approach to measured velocity values. A novel LDV technique has been proposed outlying of the critical aspects to be taken into account for future developments and improvements in measurement dynamic range, resolution, and accuracy.

scholarly journals Methodology for measuring the gap size using a fiber-optic displacement sensor exemplified by a centrifugal blood pump

2020 ◽  
Vol 12 (2) ◽  
pp. 46
Author(s):  
Maciej Gawlikowski ◽  
Przemysław Kurtyka ◽  
Jerzy Zalewski ◽  
Magda Zarwańska-Doffek ◽  
Artur Kapis
Keyword(s):  
Heart Failure ◽  
Ventricular Assist Device ◽  
Fiber Optic ◽  
Displacement Sensor ◽  
Blood Pump ◽  
Rotary Blood Pump ◽  
Assist Device ◽  
Ventricular Assist ◽  
Blood Pumps ◽  
Rotary Blood Pumps

In order to avoid blood clotting, in the second generation of rotary blood pumps the impeller is suspended without mechanical bearing, using balance of magnetic and hydrodynamic forces. Reaching single tens of microns gap between pump housing and impeller is crucial for level of blood traumatization by the pump. In this paper we would like to present the method of physical measurement of this gap on a running pump with the use of commercial fiber-optic proximity sensor on the example of Polish rotary blood pump ReligaHeart ROT. We also discussed technical requirements of the construction of laboratory stand. Full Text: PDF ReferencesS. Westaby, "Rotary blood pumps as definitive treatment for severe heart failure", Future Cardiol. 9, 2 (2013). CrossRef R. Delgado, M. Bergheim, "HeartMate® II left ventricular assist device: a new device for advanced heart failure", Epert Rev. Med. Devices, 2, 5 (2005). CrossRef M. Ozban, T. Yagdi, C. Engin et al, Transplant proc., 44, 6 (2012). CrossRef A.T. Lanfear, M. Hamandi, J. Fan et al., "Trends in HeartMate 3: What we know so far", J. Card. Surg., 35, 1 (2020). CrossRef Ch. Zengsheng, S. Anqiang, W. Hongyu, "Non-physiological shear stress-induced blood damage in ventricular assist device", Medicine in Novel Technology and Devices, 3 (2019). CrossRef A. M. Robertson, A. Sequeira, R. G. Owens, Rheological models of blood In: L. Formaggia, A. Quarteroni, A Veneziani (eds) Cardiovascular Mathematics (Milano, Springer-Verlag 2009) CrossRef M. Gawlikowski et al., "Necessity of telemonitoring in patients treated by means of cardiac assist systems on the example of Polish rotary blood pump ReligaHeart ROT", Advances in Intelligent Systems and Computing, 925 (2019). CrossRef R. Kustosz, et al., "The tin coating utilisation as blood contact surface modification in implantable rotary left ventricle assist device religaheart ROT", Arch. Matall. Mater., 60, 3 (2015). CrossRef S. S. Patil, A. D. Shaligram, "Analytical study of performance variations of fiber optic micro-displacement sensor configurations using mathematical modeling and an experimental test jig", IJSER, 4, 11 (2013). DirectLink Philtec Application Note, 6, 25 (2017) CrossRef

scholarly journals Investigation of Internal Flow in Centrifugal Pump Diffuser using Laser Doppler Velocimetry (LDV) and Computational Fluid Dynamics

2021 ◽  
Vol 1909 (1) ◽  
pp. 012075
Author(s):  
Daisuke Sugiyama ◽  
Asuma Ichinose ◽  
Tomoki Takeda ◽  
Kazuyoshi Miyagawa ◽  
Hideyo Negishi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Pump ◽  
Laser Doppler Velocimetry ◽  
Internal Flow ◽  
Laser Doppler ◽  
Doppler Velocimetry

scholarly journals Laser-Doppler Velocimetry Measurements Inside a Backward Curved Centrifugal Fan

2001 ◽  
Vol 7 (3) ◽  
pp. 173-181
Author(s):  
Tong-Miin Liou ◽  
Meng-Yu Chen
Keyword(s):  
Flow Rate ◽  
Turbulence Intensity ◽  
Laser Doppler Velocimetry ◽  
Reverse Flow ◽  
Flow Region ◽  
Design Flow ◽  
Laser Doppler ◽  
Centrifugal Fan ◽  
Doppler Velocimetry ◽  
Flow Rates

Laser-Doppler velocimetry (LDV) measurements are presented of relative mean velocity and turbulence intensity components inside the impeller passage of a centrifugal fan with twelve backward curved blades at design, under-design, and over-design flow rates. Additional LDV measurements were also performed at the volute outlet to examine the uniformity of the outlet flow for the three selected flow rates. Complementary flow visualization results in the tongue region are further presented. It is found that the number of characteristic flow regions and the average turbulence level increase with decreasing air flow rate. For the case of under-design flow rate, there are a through-flow region on the suction side, a reverse flow region on the pressure side, and a shear layer region in between. The corresponding average turbulence intensity is as high as 9.1% of blade tip velocity.

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