Abstract: A lancing mechanism fixture for puncturing skin with a lancet having a penetration end being moveable in a direction substantially parallel to the longitudinal axis of the lancet, the penetration end being moveable from a first position to a second position during a forward stroke, the penetration end being movable from the second position back to the first position during a return stroke. The motion of the lancet is controlled by a cam mechanism including a slot cam and a cam follower connected to a lancet. A drive member applies a linear force to the slot cam whose linear motion and slot path shape forces the lancet to move from a first position to a second position and back to the first position.