Inherent precision of mechanical, infrared and laser-guided navigation systems for computer-assisted surgery.

This investigation detects the inherent precision of four navigation systems, of different structural type, for computer-assisted surgery, ranging from 0.1 to 1.8 mm: the Viewing Wand with a mechanical arm, and three new systems, the SMN microscope and STP pointer with infrared technology and the MKM system with laser autofocus. For this purpose, a new standard to detect separately the inherent deviations of navigation systems from the deviations caused by acquisition of CT data sets, is introduced. The measurements are performed within a complete three-dimensional room, consisting of three orthogonal planes of a geometric model. The method introduced is valid for regular measurements of the inherent precision of navigation systems for quality assurance in order to prevent intraoperative failure caused by insufficient potentiometers, infrared transmitters or receivers.