US Patent 7141023 Micro perfusion device comprising a collecting container

A micro perfusion device including a casing, a perfusate supply, an inner cannula forming an inner lumen between a front cannula opening which is distal when the device is subcutaneously positioned and a rear cannula opening, the inner lumen being connected or connectable to the perfusate supply via the rear cannula opening, a perfusion cannula projecting from a lower side of the casing and surrounding the inner cannula, an outer lumen between the inner cannula and the perfusion cannula, a collecting container for the perfusate, and a perfusate outlet connecting the outer lumen to the collecting container, wherein the collecting container has a variable volume and a partial vacuum with respect to a pressure prevailing in the perfusate supply may be generated in the collecting container.