Medical instrument tube end, for coupling tube with end piece carrying tool, e.g. for laparoscopy, has flange, interlocking part and elastic seal in groove, providing electrical insulation and fluid-tight seal

A tube end (10) for a medical instrument, for coupling a tube (61) with an end piece (500) carrying a tool, has a flange (40) with a contact surface; a groove adjacent to the contact surface; an interlocking part (20) couplable with the end piece; and an elastically deformable seal (100), located in the groove and lying in compressed form against the contact surface when the end piece is applied to the interlocking part. Independent claims are included for: (1) an end piece (500) for coupling on the tube end (10) of a medical instrument, having a thread interlocking with the tube end, a sleeve (510) connected with the thread and an elastically deformable seal connected to the sleeve, lying in compressed state on the tube end when the end piece interlocks with the tube end; and (2) a variant of the tube end for coupling with a tube, consisting of a part for application onto the end piece, formed from semi-crystalline plastics showing electrical resistance, and a widened part coming into frictional contact with the end piece when the end piece is applied to the tube end. Beschrieben ist u. a. ein medizinisches Instrument (65) mit einem Rohrende (11) zur Kopplung eines Rohrs mit einem Endstück (500). Das Rohrende (11) hat einen Anbringteil, der an dem Endstück (500) anbringbar ist, und eine Aufweitung (31), die in reibschlüssiger Anlage mit dem Endstück (500) kommt, wenn das Endstück (500) an dem Rohrende (11) angebracht wird.