A magnetic resonance imaging system comprises means for generating a main magnetic field with a main magnetic field strength an a plurality of magnetic resonance signal receiving positions, provided by one or more receiver antennae. According to another illustrative embodiment of the present invention, an optical device includes a first optical element disposed over a structure, and a second optical element, wherein the first optical element and the second optical element are aligned with a tolerance in the range of approximately 0. A reliable communications protocol is used for communications between the first and second processors to ensure that control data sent from either one of the processors is received by the other processor. The orientation detector is coupled to the attachment member such that the orientation detector detects an orientation of the attachment member.