Computer aided surgery : official journal of the International Society for Computer Aided Surgery
-
Comput. Aided Surg. · Jan 2009
Randomized Controlled TrialComputer assisted LISS plate placement: an in vitro study.
A laboratory study was conducted to compare the accuracy with which a LISS plate could be placed on the distal metaphysis of a model femur using both a fluoroscopy-based computer assisted technique and the conventional fluoroscopic technique. A significant difference was found between outcomes with the two approaches with respect to the maximum distance from the plate to the diaphysis of the bone, but there was no significant difference in the maximum distance to the condylar area. There was also no difference with respect to the number of holes that required re-drilling for adjustment of the plate placement or screws with poor purchase in bone. There were, however, significant differences between the two techniques in terms of duration of the procedure and radiation exposure.
-
Comput. Aided Surg. · May 2008
Comparative StudyNavigated pedicle screw placement: experimental comparison between CT- and 3D fluoroscopy-based techniques.
Even with CT-based navigation, the misplacement rate for pedicle screws is reported to be as high as 10%. Using fluoroscopy-based 3D navigation, misplacement rates of 1.7 to 6% occur. The purpose of this study was to compare the accuracy of CT-based and Iso-C-based navigation in an experimental context. ⋯ The overall image-to-reality accuracy for CT- and Iso-C-based navigation was assessed in the described experimental setup. An apparent tendency towards higher accuracy with Iso-C-based navigation was evaluated; however, the differences were not significant.
-
To demonstrate the possibilities, advantages and limitations of virtual bronchoscopy using data sets from positron emission tomography (PET) and computed tomography (CT). ⋯ PET/CT imaging has proven to be a highly valuable oncological diagnostic modality. Virtual hybrid bronchoscopy can be performed using a low-dose CT scan or diagnostic CT. However, it is expected to improve diagnostic accuracy in identification and characterization of malignancies, verification of infections, and differentiation of viable tumor tissue from atelectases and scar tissue, as well as assessment of tumor staging and therapeutic response, and detection of early stage recurrences that are not detectable or are liable to be misjudged using virtual CT-bronchoscopy. It could also be useful as a screening examination method for patients with suspected endobronchial malignancy. Virtual hybrid bronchoscopy with a transparent color-coded shaded-surface rendering model offers a useful alternative to fiberoptic bronchoscopy, and is particularly promising for patients for whom fiberoptic bronchoscopy is not feasible, contraindicated or refused.
-
One of the most important advantages of computer simulators for surgical training is the opportunity they afford for independent learning. However, if the simulator does not provide useful instructional feedback to the user, this advantage is significantly blunted by the need for an instructor to supervise and tutor the trainee while using the simulator. Thus, the incorporation of relevant, intuitive metrics is essential to the development of efficient simulators. ⋯ We further describe a novel performance evaluation console that displays metric-based information during an automated debriefing session. Finally, the results of several user studies are reported, providing some preliminary validation of the simulator, the metrics, and the feedback mechanisms. Several machine learning algorithms, including Hidden Markov Models and a Naïve Bayes Classifier, are applied to our simulator data to automatically differentiate users' expertise levels.
-
Comput. Aided Surg. · Mar 2008
Comparative StudyElectromagnetic navigation improves minimally invasive robot-assisted lung brachytherapy.
Recent advances in minimally invasive thoracic surgery have renewed an interest in the role of interstitial brachytherapy for lung cancer. Our previous work has demonstrated that a minimally invasive robot-assisted (MIRA) lung brachytherapy system produced results that were equal to or better than those obtained with standard video-assisted thoracic surgery (VATS) and comparable to results with open surgery. The purpose of this project was to evaluate the performance of an integrated system for MIRA lung brachytherapy that incorporated modified electromagnetic navigation and ultrasound image guidance with robotic assistance. ⋯ A modified integrated system for performing minimally invasive robot-assisted lung brachytherapy was developed that incorporated electromagnetic navigation and an improved robotic controller. The MIRA IV system performed significantly better than standard VATS and better than MIRA III.