An apparatus comprises: a planar optical waveguide having sets of locking diffractive elements and means for routing optical signals; and corresponding lasers. The system disclosed can be non verbally started and stopped without the need for the system user to use his or her hands facilitating hands-free operation in an environment with a relatively high degree of ambient background verbal noise. During a step of evaluating a specific node, there is dynamically computed a backjump pointer according to a specific rule associated with the specific node, wherein the value of the computed backjump pointer identifies an ancestor node of the tree. The tubing and the wire are preferably copper and also preferably form each entire spark plug and ignition coil wire. An adapter supports the J end of the bassinet tube that overlies a collapsible joint assembly at the midpoint of one upper rail assembly. The surgical instrument may have a generally hemispherical shape and the internal support may comprise a non-planar shim.