Abstract: A cannulation assembly comprising: a housing; a needle selectively extendable from a proximal end of said housing; a tube arranged to pass through the housing and through a bore of said needle such that an insertion end of said tube is arranged to selectively project from an insertion end of said needle; a slide mounted to the needle in sliding engagement with the housing and arranged to move the needle from a retracted position to an insertion position such that the needle projects from said housing; wherein said slide is further arranged to move the needle from the insertion position to a locked position such that the needle is fully retracted.

Abstract: A syringe pump usable with a syringe having a barrel and a plunger, the plunger having a plunger flange, comprises a barrel retaining mechanism for holding the barrel, and a drive mechanism having a drive head assembly for driving the plunger along its axis. The drive head assembly comprises a flange retaining mechanism for retaining the plunger flange to the drive head assembly, and a load measuring device for measuring compressive force on the plunger flange, the load measuring device being movable within the drive head assembly transverse to the axis. The syringe pump comprises a self-centering mechanism having a pushing component which is arranged to move the load measuring device within the drive head assembly until the pushing component abuts against the plunger flange, such that a center of the load measuring device is aligned with the axis.