Blood filter

Abstract

A blood filter having a bubble separating section includes a generally cylindrical chamber for allowing bubbles to separate from blood, an air discharging vent at an upper end of the chamber, and an inlet conduit horizontally extending from the chamber for introducing blood into the chamber. A blood filter section is disposed below the bubble separating section, including an outlet at a lower end for discharging blood and a filter member disposed between the inlet and the outlet. The axis of the inlet conduit extends substantially parallel to a tangent line of the generally circular chamber at the connection between the chamber and the inlet conduit, but is spaced a certain distance from the tangent line in a plane perpendicular to the axis of the chamber. An inflow portion is disposed between the inlet conduit and the chamber so as to define a flowpath merging the inlet conduit to the chamber, whereby the inflow portion directs incoming blood from the inlet conduit so as to flow as a substantial laminar flow to a swirl flow of blood in the chamber and then merge with the swirl flow. The apparatus has high bubble removal capacity in that few bubbles are conveyed to the filter member since newly introduced blood does not disturb the existing swirl flow of blood in the chamber.