Connection method for MEMS navigation unit for computer-assisted surgery

An inertial navigation assembly adapted for navigating a surgical instrument using a computer-assisted surgery CAS system remote from both the inertial navigation assembly and the surgical instrument, the CAS system being in wireless communication with the inertial navigation assembly, the navigation assembly comprising:

• a micro-electromechanical sensor (MEMS) navigation unit having one or more MEMS producing at least orientation data and wirelessly transmitting the at least orientation data to the CAS system remote from the navigation assembly;
• a support including a receptacle receiving the MEMS navigation unit therein, the support being adapted to be mounted on the instrument in a fixed orientation relative to established navigated features of the instrument;
• and
• at least two connection devices connecting and aligning the MEMS navigation unit and the support, a first connection device of the at least two connection devices including a pair of spaced apart mating ball-in-socket features disposed between the MEMS navigation unit and the support at opposed ends thereof for releasably engaging the MEMS navigation unit in precise orientational alignment within the receptacle, the pair of mating ball-in-socket features being aligned along an axis extending between the opposed ends, the pair of mating ball-in-socket features comprising a first ball-in-socket feature having a biased catch and a second ball-in socket feature having a fixed catch, the biased catch and the fixed catch being received within respective sockets formed within the MEMS navigation unit or the support.