scholarly journals Numerical Investigation of Centrifugal Blood Pump Cavitation Characteristics with Variable Speed

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 293 ◽  
Author(s):  
Teng Jing ◽  
Yujiao Cheng ◽  
Fangqun Wang ◽  
Wei Bao ◽  
Ling Zhou
Keyword(s):  
Blood Circulation ◽  
Aortic Pressure ◽  
Scale Model ◽  
Blood Pump ◽  
Centrifugal Blood Pump ◽  
Multi Scale ◽  
Ansys Cfx ◽  
Blood Pumps ◽  
Cavitation Intensity ◽  
Heart Blood

In this paper, the cavitation characteristics of centrifugal blood pumps under variable speeds were studied by using ANSYS-CFX and MATLAB software. The study proposed a multi-scale model of the “centrifugal blood pump—left heart blood circulation”, and analyzed the cavitation characteristics of the centrifugal blood pump. The results showed that the cavitation in the impeller first appeared near the hub at the inlet of the impeller. As the inlet pressure decreased, the cavitation gradually strengthened and the bubbles gradually developed in the outlet of the impeller. The cavitation intensity increased with the increase of impeller speed. The curve of the variable speeds of the centrifugal blood pump in the optimal auxiliary state was obtained, which could effectively improve the aortic pressure and flow. In variable speeds, due to the high aortic flow and pressure during the ejection period, the sharp increases in speeds led to cavitation. The results could provide a guidance for the optimal design of the centrifugal blood pump.

scholarly journals A nonlinear multi-scale model for blood circulation in a realistic vascular system

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Ulin Nuha A. Qohar ◽  
Antonella Zanna Munthe-Kaas ◽  
Jan Martin Nordbotten ◽  
Erik Andreas Hanson
Keyword(s):  
Blood Flow ◽  
Blood Circulation ◽  
Vascular System ◽  
Scale Model ◽  
Model Framework ◽  
Fluid Exchange ◽  
Multi Scale ◽  
Proposed Model ◽  
Porous Media Model ◽  
Capillary Bed

In the last decade, numerical models have become an increasingly important tool in biological and medical science. Numerical simulations contribute to a deeper understanding of physiology and are a powerful tool for better diagnostics and treatment. In this paper, a nonlinear multi-scale model framework is developed for blood flow distribution in the full vascular system of an organ. We couple a quasi one-dimensional vascular graph model to represent blood flow in larger vessels and a porous media model to describe flow in smaller vessels and capillary bed. The vascular model is based on Poiseuille’s Law, with pressure correction by elasticity and pressure drop estimation at vessels' junctions. The porous capillary bed is modelled as a two-compartment domain (artery and venous) using Darcy’s Law. The fluid exchange between the artery and venous capillary bed compartments is defined as blood perfusion. The numerical experiments show that the proposed model for blood circulation: (i) is closely dependent on the structure and parameters of both the larger vessels and of the capillary bed, and (ii) provides a realistic blood circulation in the organ. The advantage of the proposed model is that it is complex enough to reliably capture the main underlying physiological function, yet highly flexible as it offers the possibility of incorporating various local effects. Furthermore, the numerical implementation of the model is straightforward and allows for simulations on a regular desktop computer.

scholarly journals A multi-scale flow model for blood regulation in a realistic vascular system

2020 ◽  
Author(s):  
Ulin Nuha Abdul Qohar ◽  
Antonella Zanna Munthe-Kaas ◽  
Jan Martin Nordbotten ◽  
Erik Andreas Hanson
Keyword(s):  
Blood Flow ◽  
Blood Circulation ◽  
Numerical Models ◽  
Scale Model ◽  
Fluid Exchange ◽  
Desktop Computer ◽  
Multi Scale ◽  
Proposed Model ◽  
Porous Media Model ◽  
Capillary Bed

Abstract In the last decade, numerical models have been an increasingly important tool in medical science both for the fundamental understanding of the physiology of the human body as well as for diagnostics and personalized medicine. In this paper, a multi-scale model is developed for blood flow and regulation in a full vascular structure of an organ. We couple a 1D vascular graph model to represent blood flow in larger vessels and a porous media model to describe flow in smaller vessels and capillary bed. The vascular model is based on Poiseuille’s law, with pressure correction by elasticity and pressure drop estimation at vessels junctions. The porous capillary bed is modeled as a two compartments domain (arterial and venal) and Darcy’s law. The fluid exchange between the arterial and venal capillary bed compartments is defined as blood perfusion. The numerical experiments show that the proposed model for blood circulation: 1) is closely dependent on the structure and parameters of both the vascular vessels and of the capillary bed, and 2) it provides a realistic blood circulation in the organ. The advantage of the proposed model is that it is complex enough to capture the underlying physiology reliably, yet highly flexible as it offers the possibility of incorporating various local effects. Furthermore, the numerical implementation of the model is straightforward and allows for simulations on a regular desktop computer.

In vitro hemocompatibility investigation for the development of low-flow centrifugal blood pumps with less platelet clogging

2021 ◽  
pp. 039139882110525
Author(s):  
Akiko Oota-Ishigaki ◽  
Takashi Yamane ◽  
Daisuke Sakota ◽  
Ryo Kosaka ◽  
Osamu Maruyama ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Low Flow ◽  
Blood Pump ◽  
Centrifugal Pumps ◽  
Aggregation Index ◽  
Centrifugal Blood Pump ◽  
Pump Design ◽  
Blood Pumps ◽  
Adhesion Rate

Low-flow blood pumps rated under 1 L/min are emerging for new medical applications, such as hemofiltration in acute use. In those pumps, platelet adhesion and aggregation have to be carefully considered because of clogging risk in the filter part. To find an acceptable hemocompatibility that can be applied to low-flow centrifugal blood pump design, the platelet aggregation index, clogging on a micromesh filter, and the hemolysis index were investigated using a low-flow blood pump designed for hemofiltration use. We conducted circulation testing in vitro using fresh porcine blood and two centrifugal pumps with different impeller inlet shapes. The Negative Log Platelet Aggregation Threshold Index (NL-PATI), which reflects the ability of residual platelets to aggregate, and flow rate were measured during reflux for 60 min, and the Normalized Index of Hemolysis (NIH (g/20 min)) was calculated. In addition, blood cell clogging after reflux was observed on the micromesh filter by SEM, and the adhesion rate was calculated. Our results showed that the platelet clogging on the micromesh filter occurred when the average NL-PATI was greater than 0.28 and the average NIH (g/20 min) was greater than 0.01. In contrast, platelet clogging on the micromesh was suppressed when NL-PATI was less than 0.17 and the NIH (g/20 min) was less than 0.003. These values might be used as acceptable hemocompatibility of low-flow centrifugal blood pumps with suppressed platelet clogging for hemofiltration pumps.

scholarly journals Geometric Optimization of an Extracorporeal Centrifugal Blood Pump with an Unshrouded Impeller Concerning Both Hydraulic Performance and Shear Stress

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1211
Author(s):  
Bo Huang ◽  
Miao Guo ◽  
Bin Lu ◽  
Qingyu Wu ◽  
Zhigang Zuo ◽  
...  
Keyword(s):  
Shear Stress ◽  
Vascular Diseases ◽  
Geometric Optimization ◽  
Blood Pump ◽  
Original Design ◽  
Centrifugal Blood Pump ◽  
Low Degree ◽  
Blood Pumps ◽  
Optimized Model ◽  
Computation Load

Centrifugal blood pumps have provided a powerful artificial support system for patients with vascular diseases. In the design process, geometrical optimization is usually needed to acquire a more biocompatible model for clinical uses. In the current paper, we propose a method for multi-objective optimization concerning both the hydraulic and the hemolytic performances of the pump based on the near-orthogonal array in which the traditional hemolysis index (HI) is replaced with the maximum scalar shear stress criteria to reduce the computation load. The method is demonstrated with the optimization of an extracorporeal centrifugal blood pump with an unshrouded impeller. CFD studies on the original and nine modified pump models are carried out. The calculated hydraulic performances of the optimized model are also compared against the experiments for validation of the numeric method, with an error of 3.6% at the original design point. The resulting blood pump with low maximum scalar shear stress (132.2 Pa) shows a low degree of calculated HI (1.69 × 10−3).

scholarly journals The Design and Evaluation of a Portable Extracorporeal Centrifugal Blood Pump

2021 ◽  
Vol 12 ◽  
Author(s):  
Peng Wu ◽  
Wenjing Xiang ◽  
Chengke Yin ◽  
Shu Li
Keyword(s):  
Heart Failure ◽  
Ring Cavity ◽  
Life Quality ◽  
Blood Pump ◽  
Centrifugal Blood Pump ◽  
Portable Pump ◽  
Blood Pumps ◽  
Patients With Heart Failure ◽  
Clinical Benefits

In recent years, blood pumps have become the bridge to heart transplantation for patients with heart failure. Portability and wearability of blood pumps should be considered to ensure patient satisfaction in everyday life. To date, the focus has been on the development of portable and wearable peripheral components, little attention has been paid to the portable and wearable performance of the blood pump itself. This study reported a novel design of a wearable and portable extracorporeal centrifugal blood pump. Based on an in-house centrifugal maglev blood pump, the wearable and portable blood pump was designed with parallel inlet and outlet pipes to improve the wearable performance. A ring cavity was set at the inlet to convert the circumferential velocity of the inlet pipe to an axial velocity. The hydraulic and hemolytic performance of the baseline and portable blood pumps were analyzed and compared. Compared with the baseline pump, the hydrodynamic and hemolytic performance of the portable pump has been maintained without serious degradation. The results of this study will improve the life quality of patients with heart failure, and enhance the clinical benefits of artificial heart.

scholarly journals Mock loop for bubble generation in a centrifugal blood pump for fault simulation

2018 ◽  
Vol 4 (1) ◽  
pp. 33-36
Author(s):  
André Stollenwerk ◽  
Mateusz Buglowski ◽  
Jan Kühn
Keyword(s):  
Blood Circulation ◽  
Laboratory Experiments ◽  
Fault Simulation ◽  
Gas Bubbles ◽  
Blood Pump ◽  
Bubble Generation ◽  
Centrifugal Blood Pump ◽  
Animal Trials ◽  
Extracorporeal Blood Circulation ◽  
Gas Volume

AbstractIn extracorporeal blood circulation intensive care treatments, the occurrence of gas within the circulation is one known major hazard. This gas volume can cause severe harm to the patient like infarctions. Consequently, within risk assessment for these treatments gas bubbles are usually addressed by either constructive or signal based approaches. All signal-based approaches do have in common that they need a sufficient amount of data to be parameterized. These data can only be acquired in animal trials or laboratory experiments, as they could result in harm to patients. Hence, we designed a mock loop, which is automatically able to create annotated data of gas bubbles injected into an extracorporeal circulation. We were able to run this setup with a periodicity of 15 seconds, which results in 240 annotated measurements per hour. For the evaluation, we created 1095 bubbles of varying sizes (0.3 to 0.5 ml). The elaborated setup enables us to produce a great amount of annotated data, which is shown to be comparable to manually generated data in a convenient and fully automated manner.

Hydraulic Analysis and Optimization in Impeller of Magnetically Levitated Centrifugal Blood Pump

2011 ◽  
Vol 121-126 ◽  
pp. 1204-1208 ◽  
Author(s):  
Hui Min Zhang ◽  
Qi Zhu
Keyword(s):  
Fluid Dynamic ◽  
Pressure Head ◽  
Blood Pump ◽  
Hydraulic Analysis ◽  
Optimization Analysis ◽  
Centrifugal Blood Pump ◽  
Optimization Of Parameters ◽  
Fluid Field ◽  
Ansys Cfx ◽  
Magnetically Levitated

This article, on the basis of the magnetically levitated pumps developed by Ibaraki University, talks about fluid dynamic analysis of pump and optimization of parameters of the impellers. The pump uses blood as medium, with a flow rate Q of 5L/min, a pressure head H of 100mmHg. By using software of ANSYS CFX, the article analyzes the effect of shape, angle, height, length and thickness of the impeller on performance chart and fluid field distribution inside the pump. To fulfill the human requirements in blood pump, an optimization analysis is conducted to improve the uniformity of fluid field, reduce power and efficiency of the pump. As result, meeting the flow and pressure head condition, single curvature impeller is found to have lower speed, better efficiency and more uniform flow field, this helps to prevent the generation of thrombus and hemolytic.

Flow characteristics and hemolytic performance of the new Breethe centrifugal blood pump in comparison with the CentriMag and Rotaflow pumps

2021 ◽  
pp. 039139882110416
Author(s):  
Ge He ◽  
Jiafeng Zhang ◽  
Aakash Shah ◽  
Zachary B Berk ◽  
Lu Han ◽  
...  
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Flow Characteristics ◽  
Pressure Head ◽  
Blood Pump ◽  
Assisted Circulation ◽  
Centrifugal Blood Pump ◽  
Blood Pumps ◽  
Flow Features

Blood pumps have been increasingly used in mechanically assisted circulation for ventricular assistance and extracorporeal membrane oxygenation support or during cardiopulmonary bypass for cardiac surgery. However, there have always been common complications such as thrombosis, hemolysis, bleeding, and infection associated with current blood pumps in patients. The development of more biocompatible blood pumps still prevails during the past decades. As one of those newly developed pumps, the Breethe pump is a novel extracorporeal centrifugal blood pump with a hybrid magnetic and mechanical bearing with attempt to reduce device-induced blood trauma. To characterize the hydrodynamic and hemolytic performances of this novel pump and demonstrate its superior biocompatibility, we use a combined computational and experimental approach to compare the Breethe pump with the CentriMag and Rotaflow pumps in terms of flow features and hemolysis under an operating condition relevant to ECMO support (flow: 5 L/min, pressure head: ~350 mmHg). The computational results showed that the Breethe pump has a smaller area-averaged wall shear stress (WSS), a smaller volume with a scalar shear stress (SSS) level greater than 100 Pa and a lower device-generated hemolysis index compared to the CentriMag and Rotaflow pumps. The comparison of the calculated residence times among the three pumps indicated that the Breethe pump might have better washout. The experimental data from the in vitro hemolysis testing demonstrated that the Breethe pump has the lowest normalized hemolysis index (NIH) than the CentriMag and Rotaflow pumps. It can be concluded based on both the computational and experimental data that the Breethe pump is a viable pump for clinical use and it has better biocompatibility compared to the clinically accepted pumps.

Dynamic Model and Analysis of a Centrifugal Blood Pump and Induction Motor

2001 ◽  
Author(s):  
P. Ruby Mawasha ◽  
Omotoye Omotoso ◽  
Paul Lam ◽  
Ted Conway
Keyword(s):  
Induction Motor ◽  
Dynamic Model ◽  
Characteristic Curve ◽  
Volumetric Flow Rate ◽  
Ventricular Assist Devices ◽  
Blood Pump ◽  
Ventricular Assist ◽  
Centrifugal Blood Pump ◽  
Blood Pumps ◽  
The Mathematical Model

Abstract A dynamic model of a centrifugal blood pump, induction motor, and channel is investigated through nonlinear analysis. A centrifugal blood pump with forward curved blades and an induction motor is subject to constant inlet and outlet mass flow conditions leading to a channel. The steady state pressure drop versus volumetric flow rate relation is described by a constitutive model containing a cubic nonlinearity obtained from centrifugal pump characteristic curves. Within certain operating regimes along the characteristic curve, the model exhibits self-excited pulsatile periodic morion and the qualitative features of the response can be understood in terms of the underlying model. Further, the mathematical model is a more general model and can be used by the designer of centrifugal blood pumps and other ventricular assist devices (VADs) to determine the instability mechanisms.

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