BLOOD PUMP

摘要

PROBLEM TO BE SOLVED: To prevent the inner bottom of a pump casing from being stuck by a thrombus by determining the ratio of the whole length of projection or groove to the diameter of an impeller and the ratio of the area that the projection and the groove contact with blood to the area that impeller is reflected as they can be within a certain area while more than one projection or groove- shaped mixing element is radially settled inside the inner bottom of the main impeller. SOLUTION: At the back of main impeller 2 that is composed of cone-shaped rotor 21 and plural fans 22 that are settled around the surface of the rotor 21, Disk-shaped mixing impeller 3 is fixed as it faces to the inside of the pump casing 10's bottom. Mixing element is composed of mixing impeller 3 at which more than one projection 41 or grooves (they are to be called 'the projection 41 and so on') that extend toward the direction of the diameter are formed. The ratio of the whole length of the projection 41 and so on to the diameter D of the impeller 2 and the ratio of the area that projection 41 and so on contact bloods to the area to which the impeller 2 are reflected should fulfill the formula 1 and the formula 2. Thus, the inner bottom of the casing 10 can be prevented from being stuck by a thrombus.