Centrifugal Blood Pump for Temporary Ventricular Assist Devices With Low Priming and Ceramic Bearings

2013 ◽  
Vol 37 (11) ◽  
pp. 942-945 ◽  
Author(s):  
Juliana Leme ◽  
Cibele da Silva ◽  
Jeison Fonseca ◽  
Bruno Utiyama da Silva ◽  
Beatriz Uebelhart ◽  
...  
Keyword(s):  
Ventricular Assist Devices ◽  
Blood Pump ◽  
Ventricular Assist ◽  
Centrifugal Blood Pump ◽  
Assist Devices

Effects of gravity on flow rate estimations of a centrifugal blood pump using the eccentric position of a levitated impeller

2020 ◽  
Vol 43 (12) ◽  
pp. 774-781
Author(s):  
Shuya Shida ◽  
Toru Masuzawa ◽  
Masahiro Osa
Keyword(s):  
Flow Rate ◽  
Ventricular Assist Devices ◽  
Blood Pump ◽  
Accurate Estimation ◽  
Ventricular Assist ◽  
Centrifugal Blood Pump ◽  
Assist Devices ◽  
Flow Estimation ◽  
Magnetically Levitated ◽  
Gravity Direction

Implantable ventricular assist devices are a type of mechanical circulatory support for assisting the pumping of the heart. Accurate estimation of the flow rate through such devices is critical to ensure effective performance. A novel method for estimating the flow rate using the passively stabilized position of a magnetically levitated impeller was developed by our group. However, the performance of the method is affected by the gravity vector, which depends on the patient’s posture. In this study, the effects of gravity on the flow estimation method are analyzed, and a compensation method is proposed. The magnetically levitated impeller is axially suspended and radially restricted by passive stability in a centrifugal blood pump developed by our group. The gravity effects were evaluated by analyzing the relationships between the radial position of the magnetically levitated impeller and the flow rate with respect to the gravity direction. Accurate estimation of the flow rate could not be achieved when the direction of gravity with respect to impeller was unknown. A mean absolute error of up to 4.89 L/min was obtained for flow rate measurement range of 0–5 L/min. However, analysis of the equilibrium of forces on the passively stabilized impeller indicated that the effects of gravity on the flow estimation could be compensated by performing additional measurements of the gravity direction with respect to impeller. The method for compensating the effects of gravity on the flow estimation should improve the performance of therapy with the implantable ventricular assist devices.

scholarly journals The CentriMag Centrifugal Blood Pump as a Benchmark for In Vitro Testing of Hemocompatibility in Implantable Ventricular Assist Devices

2014 ◽  
Vol 39 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Chris H.H. Chan ◽  
Ina Laura Pieper ◽  
Rebecca Hambly ◽  
Gemma Radley ◽  
Alyssa Jones ◽  
...  
Keyword(s):  
Ventricular Assist Devices ◽  
Blood Pump ◽  
In Vitro Testing ◽  
Ventricular Assist ◽  
Centrifugal Blood Pump ◽  
Assist Devices

scholarly journals Tribology and Crystallinity in pivot bearings of Ventricular Assist Devices

2020 ◽  
pp. 52-62
Author(s):  
Dryelle S Marquiori ◽  
Pamela C Florentino ◽  
Sergio Y Araki ◽  
Isac K Fujita ◽  
Rodrigo LO Basso ◽  
...  
Keyword(s):  
Polyamide 6 ◽  
Aortic Pressure ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Oxide Ceramic ◽  
Ventricular Assist ◽  
Centrifugal Blood Pump ◽  
Assist Devices ◽  
Poly Ether Ether Ketone ◽  
Before And After

Ventricular Assist Devices are blood pumps used in patients with Congestive Heart Failure who are waiting for a heart transplant. They aim to assist the ventricle to pump out blood in physiological circulation by increasing aortic pressure and decreasing intraventricular pressure. The IFSP Laboratory of Bioengineering and Biomaterials (BIOENG) has been developing an Implantable Centrifugal Blood Pump called CARoL for mechanical circulatory support. The objective of this dissertation is to evaluate the changes in the crystallinity of the polymeric Pivot Bearings supporting the impeller of this pump when subjected to friction generated by rotation of zirconia oxide ceramic shafts. The adopted methodology consisted of submitting new and used samples of: a) bearings set made of polyamide 6; and b) the set made of poly-ether-ether-ketone. Those new and used samples were characterized by X-ray diffraction tests and Infrared Spectroscopy. The diffractograms and spectra obtained were compared to evaluate the bearing crystallinity, for both polymers before and after friction. The tests carried out showed diffractograms and similar spectra for the new and used samples, thus, there are indications that the friction generated by the rotation of the shafts did not change the crystallinity of the polymeric bearings supporting the pump rotor.

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.

Flow rate estimation of a centrifugal blood pump using the passively stabilized eccentric position of a magnetically levitated impeller

2019 ◽  
Vol 42 (6) ◽  
pp. 291-298 ◽  
Author(s):  
Shuya Shida ◽  
Toru Masuzawa ◽  
Masahiro Osa
Keyword(s):  
Flow Rate ◽  
Estimation Method ◽  
Ventricular Assist Devices ◽  
Simple Manner ◽  
Ventricular Assist ◽  
Centrifugal Blood Pump ◽  
Assist Devices ◽  
Flow Estimation ◽  
Accuracy And Precision ◽  
Magnetically Levitated

Flow rate estimation for ventricular assist devices without additional flow sensors can improve the quality of life of patients. In this article, a novel flow estimation method using the passively stabilized displacement of a magnetically levitated impeller is developed to achieve sufficient accuracy and precision of flow estimation for ventricular assist devices in a simple manner. The magnetically levitated impeller used is axially suspended by a magnetic bearing in a centrifugal blood pump that has been developed by our group. The radial displacement of the impeller, which is restricted by passive stability, can be correlated with the flow rate because the radial hydraulic force on the impeller varies according to the flow rate. To obtain the correlation with various blood viscosities, the relationships between the radial displacements of the magnetically levitated impeller and the pressure head-flow rate characteristics of the pump were determined simultaneously using aqueous solutions of glycerol with a potential blood viscosity range. The measurement results showed that accurate steady flow rates could be estimated with a coefficient of determination of approximately 0.97 and mean absolute error of approximately 0.22 L/min without fluid viscosity measurements by using the relationships between the impeller displacement and the flow rate. Moreover, a precision of approximately 0.01 (L/min)/µm was obtained owing to a strong estimation indicator signal provided by the large displacement of the passively stabilized impeller; thus, the proposed estimation method can help ensure sufficient accuracy and precision for ventricular assist devices in a simple manner, even if the blood viscosity is unknown.

scholarly journals Filmes Finos de Alumina em substratos de alumínio 5052 por processo de Oxidação Eletrolítica à Plasma

2020 ◽  
pp. 167-180
Author(s):  
José Viana ◽  
Rosa Sá ◽  
Tamires Araujo ◽  
Rafael Ribeiro ◽  
Elidiane Rangel ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Deposition ◽  
Primary Aluminum ◽  
Film Deposition ◽  
Ventricular Assist Devices ◽  
Blood Pump ◽  
Mechanical Resistance ◽  
Ventricular Assist ◽  
Centrifugal Blood Pump ◽  
Federal Institute

Alumina, or aluminum oxide, has several applications as Biomaterial in addition to being used in machining tools, grinding, thermal insulation, shielding, refractory for heating furnaces, electrical insulators, electronic components due to its high resistance to high temperatures, hardness, mechanical resistance and chemical resistance. Its achievement is due to intermediate processes in the manufacture of primary aluminum, as well as physical and chemical deposition processes. This work aims to obtain thin films of alumina through the Plasma Electrolytic Oxidation process, using the 5052 aluminum alloy as a substrate. This study serves as a basis for applications of thin films of alumina in Implantable Centrifugal Blood Pump rotors used as Ventricular Assist Devices developed by the Laboratory of Bioengineering and Biomaterials in the Federal Institute of São Paulo. The samples were prepared with same surface area of the rotor, in order to simulate the same behavior of the rotor film deposition, thus being able to observe the morphology at different oxidation times and energies, and how the influence of time and energy on the generation of plasma micro-arcs act in the formation of the alumina film. The film was characterized with Scanning Electron Microscopy, Dispersive Energy Spectroscopy and X-Ray Diffraction. The ceramic films in the PEO are created by the reaction of the electrolytic solution with the electrical discharges produced by a source, being deposited on the surface of the samples through micro arcs. In the future, the films will be tested for cell viability, and will also be evaluated as an internal coating of Implantable Centrifugal Blood Pump for use as Ventricular Assist Device.

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