LAUSR

Artificial hearts are effective devices to treat heart failure in clinical practice and can be divided into two categories: artificial hearts and ventricular assist devices. The goal of this work was to investigate the fluidity and biological changes of in vitro sheep blood using a novel alternating current (AC) magnetohydrodynamic blood pump (central magnetic intensity: 0.9 T, alternating current frequency of the electric motor: 0-80 Hz). Blood samples were collected from five sheep and were divided into two groups: the control group (no exposure to an external magnetic field) and the exposed group (3 h of exposure to an alternating magnetic field). The blood cell counts, changes in blood viscosity, and ultrastructural changes of the blood cells under transmission electron microscopy were investigated. This study demonstrated several findings: (i) Continuous sheep blood flow can be achieved; (ii) The blood cell counts remained unchanged after 3 h of exposure to an alternating magnetic field; (iii) Compared with the control group, the high- and low-shear viscosities of the whole blood from the sheep significantly decreased after 3 h of exposure to an alternating magnetic field (P < 0.05 and P < 0.01, respectively). Plasma viscosity was significantly reduced after exposure to high-intensity alternating magnetic fields (P < 0.001); (iv) The cytoplasm of blood cells (especially erythrocytes) became lighter in color in the exposure group compared to the control group, and "beads-on-string" aggregations of black particles appeared. This work provides detailed and reliable scientific research data for the development of this type of blood pump, which may serve as a transition to the clinical artificial heart.