Fastening device, implant device, locking method, and operation method

A fastening device for implant device, the fastening device comprising at least two fastening sections, where a first fastening section is arranged with a through hole, a second fastening section is arranged with a protruding part, and where said protruding part is in place in said trough hole in a fastening device locking state, wherein the implant device is adjustable and connected to an implant device feed member, characterized in that the protruding part on the second fastening section is arranged with a trough channel having an inlet and an outlet, said through channel being arranged to receive the implant device feed member, wherein the implant device feed member is arranged to be a locking member and for being involved in the adjustment of the implant device by feeding at least one of a hydraulic or pneumatic fluid, electrical energy and an electrical signal to the implant device, wherein said inlet and outlet is accessible from the exterior of the fastening device in said fastening device locking state, wherein the first fastening section is detachably and securely locked to the second fastening section when, in said fastening device locking state, said implant device feed member is in place in the trough channel and protrudes from both the inlet and the outlet of said trough channel, wherein said fastening device is adapted to be reversible in two steps, involving to remove said implant device feed member from the through channel and thereafter detaching the first fastening section from the second fastening section.