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Hemolysis Test (hemolysis + test)
Selected AbstractsNew Centrifugal Blood Pump With Dual Impeller and Double Pivot Bearing System: Wear Evaluation in Bearing System, Performance Tests, and Preliminary Hemolysis TestsARTIFICIAL ORGANS, Issue 4 2008Eduardo Bock Abstract:, A new dual impeller centrifugal blood pump has been developed as a research collaboration between Baylor College of Medicine and Institute Dante Pazzanese of Cardiology for long-term left ventricle assist device (LVAD). A design feature of this new pump is a dual impeller that aims to minimize a stagnant flow pattern around the inlet port. Several different materials were tested in order to adopt a double pivot bearing design originally developed by Prof. Dr. Yukihiko Nosé from Baylor College of Medicine. Hydraulic performance tests were conducted with two different inlet ports' angle configurations 30° and 45°. Pump with inlet port angle of 45° achieved best values of pressure ahead and flow after 1800 rpm. Preliminary hemolysis tests were conducted using human blood. The pump showed good performance results and no alarming trace of hemolysis, proving to be a feasible long-term LVAD. [source] A Passive Magnetically and Hydrodynamically Suspended Rotary Blood PumpARTIFICIAL ORGANS, Issue 3 2009Martin Stoiber Abstract A combined hydrodynamic,magnetic bearing allows the design of rotary blood pumps that are not encumbered with mechanical bearings and magnets requiring sensors or electrical power. However, such pumps have so far needed very small and accurately manufactured gaps between rotor and housing to assure effective hydromagnetic bearing behavior. In order to use this concept in disposable pump heads, a design that allows larger rotor-housing gaps, and thus larger manufacturing tolerances, is needed. A pump with passive magnetic bearings and a gap between rotor and housing in the range of 0.5 mm was designed. Numerical simulations were performed to optimize the rotor geometry at low levels of shear stress. An experimental test stand was used to find a range of speeds and gap settings that resulted in low levels of vibration and useful pressure,flow relationships. Three different rotor geometries were tested using a viscosity-adjusted test fluid. Blood damage tests were conducted within the desirable range of speeds and gap settings. In this study stable pump performance was demonstrated at total gap widths between 0.3 and 0.7 mm at flows of 0,10 L/min, with afterloads up to 230 mm Hg. Best performance was achieved with rotors sliding on a fluid pillow between the rotor and the outer housing at a gap distance of 50 to 250 µm. The inner gap distance, between the rotor and the inner housing, could be as great as 500 µm. Hemolysis tests on the prototype within the chosen operating range showed lower values (NIH = 0.0029 ± 0.0012 g/100 L) than the Biomedicus BP-80 pump (NIH = 0.0033 ± 0.0011 g/100 L). In conclusion, it is possible to build rotary blood pumps with passive hydromagnetic bearings that have large gaps between their rotors and housings. Rotor behavior is sensitive to the position of the permanent magnetic drive unit. To minimize vibration and blood damage, the fluid gaps and the rotational speed have to be adjusted according to the desired operating point of the pump. Further study is needed to optimize the magnetic drive unit and to ascertain its ability to withstand inertial loads imposed by sudden movements and external shock. [source] Congenital dyserythropoietic anemia type II with a positive sucrose hemolysis testAMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2002Prasad Rao Koduri No abstract is available for this article. [source] Improvement of Hemocompatibility in Centrifugal Blood Pump With Hydrodynamic Bearings and Semi-open Impeller: In Vitro EvaluationARTIFICIAL ORGANS, Issue 10 2009Ryo Kosaka Abstract We have developed a noncontact-type centrifugal blood pump with hydrodynamic bearings and a semi-open impeller for mechanical circulatory assist. The impeller is levitated by an original spiral-groove thrust bearing and a herringbone-groove journal bearing, without any additional displacement-sensing module or additional complex control circuits. The pump was improved by optimizing the groove direction of the spiral-groove thrust bearing and the pull-up magnetic force between the rotor magnet and the stator coil against the impeller. To evaluate hemocompatibility, we conducted a levitation performance test and in vitro hemocompatibility tests by means of a mock-up circulation loop. In the hemolysis test, the normalized index of hemolysis was reduced from 0.721 to 0.0335 g/100 L corresponding to an expansion of the bearing gap from 1.1 to 56.1 µm. In the in vitro antithrombogenic test, blood pumps with a wide thrust bearing gap were effective in preventing thrombus formation. Through in vitro evaluation tests, we confirmed that hemocompatibility was improved by balancing the hydrodynamic fluid dynamics and magnetic forces. [source] Hemocompatibility Evaluation With Experimental and Computational Fluid Dynamic Analyses for a Monopivot Circulatory Assist PumpARTIFICIAL ORGANS, Issue 4 2009Masahiro Nishida Abstract:, The hemocompatibility of a newly developed monopivot circulatory assist pump was evaluated by the computational fluid dynamic (CFD) analyses with the particle tracking velocimetry measurement. Results were compared with those of the hemolysis test and in vitro antithrombogenic test to prevent hemolysis and thrombus formation inside the pump. The results of the CFD analysis and the particle tracking velocimetry had a good agreement with each other. The flow distributions by the CFD analysis indicated that the radial jet out of the impeller was adequately weak so that the wall shear stress was lower than 300 Pa on the volute casing wall. It corresponded with the hemolysis tests results, indicating that the hemolysis level was lower than that of the commercially available pump. However, the flow distributions also indicated that the pivot that was easy to stagnate was washed out, not only by the secondary flow through the back gap of the impeller, but also by the vortices generated by the secondary vanes. It corresponded with the in vitro antithrombogenic test results, indicating that thrombus formation could be removed only by redesigning the geometry of the secondary vanes. [source] New Centrifugal Blood Pump With Dual Impeller and Double Pivot Bearing System: Wear Evaluation in Bearing System, Performance Tests, and Preliminary Hemolysis TestsARTIFICIAL ORGANS, Issue 4 2008Eduardo Bock Abstract:, A new dual impeller centrifugal blood pump has been developed as a research collaboration between Baylor College of Medicine and Institute Dante Pazzanese of Cardiology for long-term left ventricle assist device (LVAD). A design feature of this new pump is a dual impeller that aims to minimize a stagnant flow pattern around the inlet port. Several different materials were tested in order to adopt a double pivot bearing design originally developed by Prof. Dr. Yukihiko Nosé from Baylor College of Medicine. Hydraulic performance tests were conducted with two different inlet ports' angle configurations 30° and 45°. Pump with inlet port angle of 45° achieved best values of pressure ahead and flow after 1800 rpm. Preliminary hemolysis tests were conducted using human blood. The pump showed good performance results and no alarming trace of hemolysis, proving to be a feasible long-term LVAD. [source] | ||||||||||