An Overview of Robotics in Functional Neurosurgery <s> Error and Its Minimization in Functional Neurosurgery <s> This paper discusses the benefits that arise from the use of a robot arm for guiding neurosurgical operations. The design and operation of the PathFinder, safety issues and the accuracies that can be obtained and the use of a robot held camera for system calibration are described. <s> BIB001 </s> An Overview of Robotics in Functional Neurosurgery <s> Error and Its Minimization in Functional Neurosurgery <s> BACKGROUND ::: Brain biopsies (BB) and depth electrode placements (DEP) are increasingly performed using frameless stereotactic targeting devices. This paper is intended to provide a comprehensive review of the technical features, targeting errors and clinical results. ::: ::: ::: METHODS ::: A PubMed literature search from 1995-2010 was performed. ::: ::: ::: RESULTS ::: (A) Modified stereotactic arcs, (B) arm-based devices with and without aiming facilities, and (C) skull affixed devices were found. Guidance technologies were navigation systems (all groups), prospective stereotaxy and custom designed platforms (group C). Mean total errors ranged between 4.4 and 5.4 mm for BB and 2.0 and 3.2 mm for DEP. Diagnostic yield of BB was 89-100%. The clinical success rate for DEP was 96-100%. ::: ::: ::: CONCLUSIONS ::: Frameless stereotactic targeting devices may reach targeting errors and clinical results comparable with standard frame-based stereotaxy. Advantages and disadvantages of different devices should be acknowledged to ensure optimal technical performance. <s> BIB002 </s> An Overview of Robotics in Functional Neurosurgery <s> Error and Its Minimization in Functional Neurosurgery <s> Intraoperative imaging disrupts the rhythm of surgery despite providing an excellent opportunity for surgical monitoring and assessment. To allow surgery within real-time images, neuroArm, a teleoperated surgical robotic system, was conceptualized. The objective was to design and manufacture a magnetic resonance-compatible robot with a human-machine interface that could reproduce some of the sight, sound, and touch of surgery at a remote workstation. University of Calgary researchers worked with MacDonald, Dettwiler and Associates engineers to produce a requirements document, preliminary design review, and critical design review, followed by the manufacture, preclinical testing, and clinical integration of neuroArm. During the preliminary design review, the scope of the neuroArm project changed to performing microsurgery outside the magnet and stereotaxy inside the bore. neuroArm was successfully manufactured and installed in an intraoperative magnetic resonance imaging operating room. neuroArm was clinically integrated into 35 cases in a graded fashion. As a result of this experience, neuroArm II is in development, and advances in technology will allow microsurgery within the bore of the magnet. neuroArm represents a successful interdisciplinary collaboration. It has positive implications for the future of robotic technology in neurosurgery in that the precision and accuracy of robots will continue to augment human capability. <s> BIB003 </s> An Overview of Robotics in Functional Neurosurgery <s> Error and Its Minimization in Functional Neurosurgery <s> Accurate patient registration is a critical issue in medical image-guided interventions. The neurosurgical robotic system RObotic Neuro-NAvigation (RONNA) uses four retro-reflective spheres, on a marker attached to the patient’s cranial bone, for patient registration in physical and image space. In this paper, the algorithm for automatic localization of spherical fiducials in CT scans is presented and clinically evaluated. The developed localization algorithm uses a unique approach, which combines machine vision algorithms, biomedical image filtration methods, and mathematical estimation methods. The performance of the localization algorithm was evaluated in comparison with four skilled human operators. The measurements were based on twelve patient and eight lab phantom CT scans. The localization error of the algorithm in comparison with the human readings was smaller by 49.29% according to the ground truth estimation and by 45.91% according to the intra-modal estimation. Localization processing time was reduced by 84.96%. Reliability in terms of successful localization of the fiducial marker was 100% for 20 different test samples containing a total of 116 spherical fiducials. Based on the tests carried out in clinical conditions, the localization algorithm has demonstrated reliability with a high degree of accuracy and short processing time. The developed algorithm provides fully automated and accurate machine vision-based patient localization for the neurosurgical clinical application of the robotic system RONNA. <s> BIB004 </s> An Overview of Robotics in Functional Neurosurgery <s> Error and Its Minimization in Functional Neurosurgery <s> BACKGROUND ::: Robotic neuronavigation is becoming an important tool for neurosurgeons. We present a case study of a frameless stereotactic biopsy guided by the RONNA G3 robotic neuronavigation system. ::: ::: ::: METHODS ::: A 45 year-old patient with a history of vertigo, nausea and vomiting was diagnosed with multiple periventricular lesions. Neurological status was unremarkable. A frameless robotic biopsy of a brain lesion was performed. ::: ::: ::: RESULTS ::: Three tissue samples were obtained. There were no intraoperative or postoperative complications. Histological analysis showed a B-cell lymphoma. After merging the preoperative CT scan with the postoperative MRI and CT scans, the measured error between the planned and the postoperatively measured entry point was 2.24 mm and the measured error between the planned and postoperatively measured target point was 2.33 mm. ::: ::: ::: CONCLUSIONS ::: The RONNA G3 robotic system was used to navigate a Sedan brain biopsy needle to take tissue samples and could be a safe and precise tool for brain biopsy. <s> BIB005 </s> An Overview of Robotics in Functional Neurosurgery <s> Error and Its Minimization in Functional Neurosurgery <s> OBJECTIVE The aim of this study was to determine whether a modified registration method could reduce registration error and postoperative electrode vector error and to analyze the method's clinical significance in deep brain stimulation (DBS) surgery. METHODS The first part of the study involved a skull model, in which three registration methods were tested using the ROSA (robotic stereotactic assistance) system. In the second part, four registration methods were clinically tested in patients undergoing DBS surgery using the ROSA system. Thirty-three patients (65 sides, group I) underwent the conventional registration method 2E, and registration errors were recorded. Thirty-eight patients (75 sides, group II) underwent four types of modified registration methods including 2A, 2B, 2C, and 2D. Registration and electrode vector errors, intraoperative electrophysiological signal length (IESL), and DBS power-on voltage were recorded. The primary measure of efficacy was the change in the Unified Parkinson's Disease Rating Scale (UPDRS) and UPDRS Part III scores from baseline to 10 weeks after surgery. RESULTS In the skull model, the registration error (mean ± SD) was 0.56 ± 0.11 mm for method 1A, 0.35 ± 0.11 mm for method 1B (vs. 1A, p < 0.001), and 0.90 ± 0.15 mm for method 1C (vs. 1A, p < 0.001). In the clinical study, method 2C was selected for DBS surgery in group II since it had the smallest registration error among the four methods tested. The registration error was 0.62 ± 0.22 mm (mean ± SD) for group I and 0.27 ± 0.07 mm for group II (p < 0.001). Postoperative electrode vector error was 0.97 ± 0.31 mm for group I and 0.65 ± 0.23 mm for group II (p < 0.001). There was a positive correlation between registration error and electrode vector error in both groups (group I: r = 0.69, p < 0.001; group II: r = 0.71, p < 0.001). The mean IESL was 5.0 ± 0.9 mm in group I and 5.8 ± 0.7 mm in group II (p < 0.001). The mean DBS power-on voltage was 1.63 ± 0.44 V in group I and 1.48 ± 0.38 V in group II (p = 0.027). In the UPDRS score, group I showed 50% ± 16% improvement and group II showed 52% ± 18% improvement (p = 0.724); there was no statistically significant difference in improvement on the UPDRS. CONCLUSIONS In DBS surgery assisted by the ROSA system, registration error and electrode vector error showed a positive correlation. The modified registration method could reduce the registration error and electrode vector error, but the long-term effects need to be further observed and evaluated. <s> BIB006
A complete DBS surgical procedure involves skin incision, dissection, burr-hole placement, dural incision, electrode array placement and recording, and permanent electrode placement followed by wound closure. The procedures of frame fixation, image acquisition, fusion, and registration occur prior to the actual surgery. The time from burr-hole placement to burr-hole closure after the electrode fixation is crucial and has the maximum risk of workflow error. The final trajectory from the skin surface to the target tissue is linear. The end actuator system for this phase of surgery has to be strictly linear with one direction of freedom. Prismatic or helical joints are ideal joints at the last set of effectors in contact with the skull. The number of joints in relation to the skull has to be minimized to reduce errors. The size of the subthalamic nucleus is approximately 3 mm. Even if a 10% error margin is considered, the device should be able to reach a given spatial target with an error less than 0.3 mm from the target tissue in 3D space. Current documentations of error during stereotactic procedures are in the range of 2 mm. BIB002 BIB005 Newer techniques and developments are expected to reduce the errors further as more and more automation enters into the workflow. BIB003 BIB006 BIB004 Sources of error in robotic stereotactic procedures have been studied in detail. BIB002 BIB001 These include imaging resolution, distortions in image acquisition and the display system, anatomical changes that may occur between image acquisition and the actual surgery; registration errors between patient and the imaging; camera, tool, and robot calibration errors; and kinematic errors. Regarding stereotactic brain procedures, the access path from the dural entry point to the target is blind. There is no visual confirmation regarding the accuracy of having reached the target. This is somewhat mitigated by image guidance systems and microelectrode recordings for DBS procedures. These techniques in turn have been advancements on the earlier techniques of brain atlas-based localizations. Even with current (nonrobotic) practices, the issues of brain-shift, frame errors, and image acquisition issues persist to varying extents. It is in this context that robots would play a major role in the near future in minimizing error. Developing a single robot that can perform skin incision, scalp dissection, and retraction is a difficult proposition. Benefits of developing tools to this end are not of relevance, as the chances of error occurring during these steps are minimal. From the point of burr-hole placement to the electrode implant stage, robotic devices can minimize error. It is thus imperative that a fully dedicated functional neurosurgery robot should have multiple components dedicated to diverse tasks such as burr-hole placement, dural incision, prevention of intradural air entry, and electrode array deployment and implantation. Some of the tasks may require dedicated separate modules, for example drills, and haemostatic devices. The other elements such as the electrode array, electrode implantation, and testing components are best designed coaxial and brought into play at relevant points of time. The surgical steps after burr-hole placement up to electrode delivery and implant delivery have to be a seamless robotic procedure.