Abstract: The system for treating an internal organ has a generator source for producing a shock wave connected to a handheld or small shock wave applicator device 2, wherein the external housing 16 of the device 2 is hermetically sealed in a non-electrically conductive insulating skin membrane 5 being of a polymer material, preferably a silicone rubber or polyurethane rubber. Preferably the entire device 2 including the connectors 32, 33 and at least a 20 cm portion of attached cable 1 is sealed using a dip coating process or alternatively can use an insert molding process wherein the device 2 is placed in a mold 400 and the skin membrane 5 is injection molded around the entire housing 16 and the cable 1 has an outer skin 5 that abuttingly seals at a connection 32, 33 to the housing 16. The device 2 may further include an internal vacuum conduit connected to a vacuum system to detect leakages and in use may be used with a sterile sleeve cover with a similar vacuum system for leakage detection.