of inlet 2 c this in turn creates a diverging profile from first predetermined diameter 23 c of inlet 2 c to third predetermined diameter 27 c of swirl inducing portion 16 c followed by a converging profile from third predetermined diameter 27 c to throat 21 c diverging portion 11 c has second predetermined diameter 25 c and is further illustrated as having a predetermined length 13 c as illustrated in fig1 in an embodiment predetermined length 13 c is 1 centimeter as in the first and second embodiments diverging portion 11 c diffuses the flow of blood thereby reducing its exit velocity and surface 12 c of diverging portion 11 c makes an angle 14 c with longitudinal axis 8 c in an embodiment angle 14 c is 7 degrees as noted previously embodiments of diverging portion 11 c can be provided with either a conical or a flared configuration fig1 13 and 14 disclose four lobes 18 c which are helically disposed about longitudinal axis 8 c but are more pronounced and more defined than lobes 18 b in the second embodiment in an alternate embodiment not shown the cannula tip may have a plurality of lobes comprising of at least four lobes in another alternate embodiment not shown the cannula tip may have a plurality of lobes comprising of at least about four lobes furthermore lobes 18 c encompass a 360 degree u201c twist u201d or helical rotation along longitudinal axis 8 c of swirl inducing portion 16 c in another embodiment lobes 18 c encompass at least a 360 degree u201c twist u201d or helical rotation along longitudinal axis 8 c of swirl inducing portion 16 c in another embodiment.