A control device for providing a reconfigurable operator interface for a medical apparatus is provided. The control device comprises a control surface comprising at least one control actuator arranged on the control surface. The control device further comprises a plurality of modules arranged side-by-side and attached to each other via adjacent abutting side surfaces in a liquid-tight manner, wherein the plurality of modules comprise a first terminal module having a closing end surface and an abutting side surface opposite the closing end surface, and a second terminal module having an abutting side surface facing towards the abutting side surface of the first terminal module, and an opposite closing end surface. Operation of the control device is enabled when all the abutting side surfaces of the plurality of modules are in an attached state.