US Patent 10117989 Syringe type pump

The subcutaneous injection device contains a pump and a mechanism for inserting a cannula into the patient's skin. The cannula is fixedly positioned relative to the pump and the insertion mechanism has a flexible surface adhering to the skin. The flexible surface is positioned relative to the cannula in such a way that in a first position the tip of the cannula is concealed by the surface and in a second position the cannula is exposed beyond the surface. The insertion mechanism brings the surface from the first to the second position, thereby pulling the skin against the tip of the cannula.