Abstract: The invention relates to a power supply unit (SCC) for generating a protective current (sealing current), which is superposed on signal currents carried by metal lines for protection against corrosion at tie points or splices of the metal lines, wherein the power supply unit is particularly suited for delivering ANSI T1.601-1992 conformant protective currents (sealing currents) for digital user terminal lines. It exhibits two voltage-controlled power sources (J1, J2), wherein the first power source (J1) is capable, depending on an applied voltage (UC1), of outputting a constant current (I1) having a first value of 0 mA, or a constant current (I1) having a second value of at least 1 mA, in particular 1.

Abstract: The invention relates to a middle ear prosthesis comprising an artificial ear drum (20) and a tubular housing which is tightly joined to said ear drum. The housing consists of a coupling element (28) and a transmitting element (22). The coupling element (28) comprises firstly an open end area (30), configured for resting against the tympanic wall (32) of an ear, and secondly, inside its inner space, a retaining device (34) for a first ossicle part (26) which extends through a small, artificially created opening (36) in the stapes base-plate (38). The transmitting element (22) is connected to the ear drum (20), on the inner surface of which is attached a second ossicle part (24), which comes into contact with and is connected to the first ossicle part (26) when the coupling element (28) and transmitting element (22) are put together.

Abstract: A pressure compensation device for a prosthetic substitute of a eustachian tube has an outer part and an inner part. The outer part serves for the admission of air from the outside and has a freely accessible area laterally surrounded by skin. Further, the outer part is provided with a seat for receiving a filter. This filter is accessible from the outside and keeps away coarse dirt and water. The outer part and the inner part are interconnected by a first tube. The inner part has a sealed housing divided into two chambers, namely an outer chamber communicating with the first tube and an inner chamber. These chambers are separated by either a fine filter or by a pressure compensation membrane to assure a germ tight separation. The inner chamber is connected with a second tube ending in a middle ear.