Abstract
Almost all pumps for presently available blood purification systems are roller pumps. We are developing a system of a small centrifugal blood pump with a vascular access to peripheral vein in order to downsize the hemofiltration systems for easy transportation and to make its use safer. We have developed small centrifugal pumps: NY1, NY2 and NY3 whose impeller diameters are 30 mm. NY4 and NY5 whose impeller diameters are 34 mm. Their impellers are supported with double pivot bearing. Another difference of NY pumps is pivot contact areas. Their contact angle of prospect are 30° for NY1 and NY5, 45° for NY2, and 60° for NY3 and NY4. These pumps provides stable blood flow of 50 mL/min. Hemolysis tests were conducted fir all pumps. The total quantity of plasma free hemoglobin of all pumps were found to be under half of that of a commercial centrifugal pump for extracorporeal circulation. Especially it was found that NY5 pump showed only 10 percent hemolysis compared to a commercial centrifugal pump.
