| Summary: | 碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 100 === Para-Aortic Blood Pump ( PABP ) is a novel left ventricular assist device. To ensure minimal thrombosis and hemolysis, four methods were used in this study. First, tracer particle visualization was used to reveal basic flow patterns. Second, dye dilution method results can identify if any residual non-replaceable fluid still remained inside the PABP. Third, dye washout method evaluated the surface washing effect. Last, particle image velocimetry (PIV) was applied to quantify the flow fields.
The results of tracer particle visualization showed a counterclockwise vortex pattern inside the blood chamber of PABP. The results of dye dilution method proved good replacement that can prevent blood disease. The results of dye washout method indicated uniform washing on the wall.
The results of PIV also showed a counterclockwise vortex pattern in PABP during diastole, and the maximum velocity was measured near 100 cm/sec. After analyzing the velocity, vorticity, and shear rate fields, one can conclude that both maximum velocity and shear rate happened right in the start of diastole. By calculating strain field of the flow, the maximum instaneous shear stress was found to be 0.4 N/m2, which was far less than the value of erythrocyte deformability: 50 N/m2 and the value of platelet activation: 10 N/m2. Therefore, the current PABP design is proven to be a low risk of thrombosis and hemolysis during diastole.
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