Blood lancet device for withdrawing blood for diagnostic purposes

Blood lancet device for withdrawing blood for diagnostic purposes, comprising

• a lancet (34) comprising a metal needle (166, 176) with a tip (35), a plastic body (165) connected to said metal needle (166, 176), and a lancet positioning means (169, 178),
• a housing (1) with an outlet (84) for the tip (35) of the lancet (34),
• a lancet holder (6) located within the housing and contacting the lancet (34) for holding the lancet (34) and movable within the housing (1) along a predetermined puncture path, and
• a lancet drive means (3) located within the housing for moving the lancet in a puncturing direction comprising an elastic drive element (9), a transmission system driven by said elastic drive element to contact and move the lancet positioning means (169, 178) through a precisely defined maximum longitudinal displacement, and
• wherein the lancet holder accurately positions the lancet positioning means (169, 178) relative to the lancet drive (3) means such that the puncture depth at which during the puncturing movement tip (35) of the lancet (34, 175) emerges from the outlet (84) varies by no more than at most .+-.0.15 mm with unchanged setting of the blood lancet device and successive puncturing movements.

Blood lancet device for withdrawing blood for diagnostic purposes comprising

• a lancet (34) comprising a metal needle (166, 176) with a tip (35) and a plastic body (165),
• a lancet holder (6) for holding the lancet (34),
• a lancet drive means (3) for driving the lancet needle (166, 176) along a predetermined straight path, the driving means comprising
• a driver input member rotatable about an axis parallel to the straight path, a driver output member connected to the lancet and the driver input member for converting the rotation of the driver input into longitudinal movement of the lancet along said straight path, and
• means for accurately positioning the metal needle (166, 176) of the lancet (34) relative to the driving means, thereby accurately to control the puncture depth of the tip (35), the positioning means comprising a positioning means surface (169) on the needle (166, 176), a stop (170) on the lancet holder (6) for abutting the positioning means surface (169), and elastic means for pressing the positioning means surface (169) against the stop (170).