Registration-Free Workflow for Electromagnetic and Optical Navigation in Orbital and Craniofacial Surgery

Abstract

The accuracy of intra-operative navigation is largely dependent on the intra-operative registration procedure. Next to accuracy, important factors to consider for the registration procedure are invasiveness, time consumption, logistical demands, user-dependency, compatibility and radiation exposure. In this study, a workflow is presented that eliminates the need for a registration procedure altogether: registration-free navigation. In the workflow, the maxillary dental model is fused to the pre-operative imaging data using commercially available virtual planning software. A virtual Dynamic Reference Frame on a splint is designed on the patient’s fused maxillary dentition: during surgery, the splint containing the reference frame is positioned on the patient’s dentition. This alleviates the need for any registration procedure, since the position of the reference frame is known from the design. The accuracy of the workflow was evaluated in a cadaver set-up, and compared to bone-anchored fiducial, virtual splint and surface-based registration. The results showed that accuracy of the workflow was greatly dependent on tracking technique used: the workflow was the most accurate with electromagnetic tracking, but the least accurate with optical tracking. Although this method offers a time-efficient, non-invasive, radiation-free automatic alternative for registration, clinical implementation is hampered by the unexplained differences in accuracy between tracking techniques.

Comparison of Freehand Technique and a Novel Laser-Guiding Navigation System in Femoral Neck-Cannulated Screw Fixation: A Randomized Controlled Trial

“…Among them, the key characteristics [20] of optical navigation are optical location tracking and image registration, which require technically demanding and dedicated equipment, more time registration, higher cost, and lower penetration [21] . Initially, accord to the Desargues's theorem [23][24] , we wanted to design the laser-positioning navigation device, which could easily complete the intraoperative positioning accurately and is easy to promote, based on existing equipment [9] .…”

Comparison of freehand technique and a novel laser-guiding navigation system in femoral neck-cannulated screw fixation: a randomized controlled trial

“…Among them, the key characteristics [ 21 ] of optical navigation are optical location tracking and image registration, which require technically demanding and dedicated equipment, more time registration, higher cost, and lower penetration [ 22 ]. Initially, accord to the Desargues’s theorem [ 23 , 24 ], we wanted to design the laser-positioning navigation device, which could easily complete the intraoperative positioning accurately and is easy to promote, based on existing equipment [ 9 ].…”