Noninvasive Tracking of Patient's Head Movements During Computer‐Assisted Intranasal Microscopic Surgery

Abstract

A noninvasive system designed for patient tracking during image-guided intranasal sinus surgery is described. It is based on optical digitizing with a custom-made registration and reference system, locatable surgical instruments, and a self-localizing operating microscope. Experimental and clinical results reveal a high degree of accuracy for the system. A mean spatial error of 0.82 +/- 0.31 mm was determined for repositioning of the reference system in a plastic model of the skull. For the positioning of the microscope, a mean error of 2.3 +/- 0.83 mm was calculated. Measurements of repositioning accuracy in 24 patients who received surgery for various sinus diseases had a mean spatial error of 1.56 +/- 0.76 mm. The 95% error interval for locating intranasal structures using the surgical instrument was 2.05 mm, and it was 4.92 mm using the microscope. These results suggest that the use of our noninvasive registration and reference system may be effective, accurate, and useful for noninvasive tracking of patient movements in computer-assisted intranasal surgery.

Navigation-assisted Surgery for Bone and Soft Tissue Tumors With Bony Extension

“…This system shows the 3-D virtual real image and has little error. Regarding the registration error using fiducial skin markers, early trials showed displacements from the CT data as large as 2 to 4 mm at the time of surgery, and this was concluded to be an unacceptable accuracy; thus, use of the noninvasive fiducial was inadequate [12].…”

“…Computer-assisted surgery has been performed for cranial biopsies and tumor resections for two decades [6,12,13,21,24,26,34] before being introduced to the field of orthopaedics [1, 5, 8, 9, 11, 15-17, 19, 23, 29, 30]. Currently, navigation systems often use CT data to navigate pedicle screw applications [1,11,17], cup placements for hip arthroplasties [16], TKAs [8,19], and cruciate ligament reconstructions [9,23].…”

Image guided surgery of the lateral skull base: Testing a new dental splint registration device

“…Although the more distant targets yielded slightly larger values, confirming the significant impact of the distance between the registration and target points on the accuracy [7,8,21], even the maximum deviation of 1.2 mm is still within the range (1 to 2 mm) that is often considered ''clinically acceptable'' for navigation system accuracy [1,21,25,26]. Maxillary splint-based systems with extraoral extensions for reference markers have been used previously with sufficient navigational accuracy in neurosurgery (0.29-0.86 mm [17], 0.0-2.0 mm [27]), in sinus surgery (1.56 AE 0.76 mm [28]), and in the temporal region (0.73 AE 0.25 mm [17,29]); however, only a few of these systems have been tested for targets in the lateral skull base region [15,29,30,31]. Bale et al used a mouthpiecebased registration template held in place by a vacuum system to successfully cannulate the foramen ovale [30], but did not test its applicability for Figure 3.…”

“…Furthermore, depending on the size and weight of the extensions, the extraoral parts might act as a lever, leading to dislocation of the maxillary splint and poor registration accuracy. Additionally, extraoral support of the reference frame by the nasion or external auditory canal [28] is not advisable, as the attachment of reference structures to soft tissue tends to increase inaccuracy because of soft tissue deformity, a problem also known from non-rigidly mounted registration devices like headbands or headsets [32]. In an attempt to solve this problem, we took special care to make our dental splint device as lightweight and as small as possible.…”

Design and Evaluation of a System for Microscope-Assisted Guided Interventions (MAGI)

“…Dental appliances such as occlusal splints and bite blocks have been proposed for use as positional reference devices [9,10]. For our purposes the standard occlusal splint was redesigned to maximise retention and stability with the aim of improved repeatability of placement.…”