Abstract: The invention relates to a device for removing a gas from an aqueous liquid, particularly a blood liquid, comprising a first compartment permeated by the aqueous liquid during operation of the device; a second compartment permeated by a purging gas during operation of the device, the first compartment and the second compartment being separated from each other by a semipermeable membrane; and a third compartment permeated by a liquid proton donor during operation of device, said proton donor being an organic or inorganic acid, the first compartment and the third compartment being separated from each other by a membrane permeable to ions, and the membrane permeable to ions comprising at least one cation conductor.

Abstract: In various exemplary embodiments, a modular cannula device is provided that has an external, tubular cannula, a first tubular guide part which has a tapering distal end and can be inserted into the cannula so that its outer wall rests tightly against the inner wall of the cannula, and a second tubular guide part, which has a tapering, pointed distal end and can be inserted into the first guide part so that its outer wall rests tightly against the inner wall of the first guide part.