The medialization laryngoplasty is a surgical procedure to improve the voice function of the patient with vocal fold
paresis and paralysis. An image guided system for the medialization laryngoplasty will help the surgeons to accurately
place the implant and thus reduce the failure rates of the surgery. One of the fundamental challenges in image guided
system is to accurately register the preoperative radiological data to the intraoperative anatomical structure of the patient.
In this paper, we present a combined surface and fiducial based registration method to register the preoperative 3D CT
data to the intraoperative surface of larynx. To accurately model the exposed surface area, a structured light based stereo
vision technique is used for the surface reconstruction. We combined the gray code pattern and multi-line shifting to
generate the intraoperative surface of the larynx. To register the point clouds from the intraoperative stage to the
preoperative 3D CT data, a shape priori based ICP method is proposed to quickly register the two surfaces. The proposed
approach is capable of tracking the fiducial markers and reconstructing the surface of larynx with no damage to the
anatomical structure. We used off-the-shelf digital cameras, LCD projector and rapid 3D prototyper to develop our
experimental system. The final RMS error in the registration is less than 1mm.