Preliminary Evaluation of a Novel Neural Network-Based Hybrid Simulator for Surgical Training and Performance Assessment of Neonatal Thoracentesis.

INTRODUCTION: Tension pneumothorax is a rare and life-threatening situation in neonates requiring immediate intervention through thoracentesis. Significant complications can arise while performing thoracentesis in the case of inadequate skill level or exposure to the condition. Although simulation-based training (SBT) has proven to be effective in learning surgical skills, training sessions are long, subjective, and expensive, because of which they cannot be held regularly. This article attempts to improve traditional SBT for neonatal thoracentesis through an autonomous simulator that can provide real-time objective feedback during surgical training and assessment. METHODS: The simulator incorporates a custom manikin and virtual reality software interfaced through electromagnetic sensors that track the motion of surgical instruments. The software application reads and stores instrument motion information to replicate physical actions in the virtual environment, play back previously stored surgical performances and analyze data through a pretrained neural network. The simulator encapsulates the experience of SBT by allowing trainees to watch and replicate an ideal method of conducting the procedure, providing simplified, real-time autonomous guidance during practice and an objective taskwise assessment of the performance during testing. RESULTS: The preliminary trial held at the University of Illinois Hospital in the presence of 1 neonatologist and 4 fellows revealed that all the participants used the autonomous guidance more than once, and all found simulation experience to be accurate and overall effective in learning thoracentesis. CONCLUSION: Although the sample size is small, the simulator shows potential in being a viable alternative approach for training and assessment for thoracentesis.

Feasibility and Acceptability of Game-Based Cortical Priming and Functional Lower Limb Training in a Remotely Supervised Home Setting for Chronic Stroke: A Case Series.

Background: Movement-based priming has been increasingly investigated to accelerate the effects of subsequent motor training. The feasibility and acceptability of this approach at home has not been studied. We developed a game-based priming system (DIG-I-PRIMETM) that engages the user in repeated ankle movements using serious games. We aimed to determine the feasibility, acceptability, and preliminary motor benefits of an 8-week remotely supervised telerehabilitation program utilizing game-based movement priming combined with functional lower limb motor training in chronic stroke survivors. Methods: Three individuals with stroke participated in a telerehabilitation program consisting of 20-min movement-based priming using the DIG-I-PRIMETM system followed by 30-min of lower limb motor training focusing on strength and balance. We evaluated feasibility using reported adverse events and compliance, and acceptability by assessing participant perception of the game-based training. Motor gains were assessed using the 10-m walk test and Functional Gait Assessment. Results: All participants completed 24 remotely supervised training sessions without any adverse events. Participants reported high acceptability of the DIG-I-PRIMETM system, reflected by high scores on satisfaction, enjoyment, user-friendliness, and challenge aspects of the system. Participants reported overall satisfaction with our program. Post-training changes in the 10-m walk test (0.10-0.31 m/s) and Functional Gait Assessment (4-7 points) exceeded the minimal clinically important difference. Conclusion: Our results indicate that a remotely supervised game-based priming and functional lower limb exercise program is feasible and acceptable for stroke survivors to perform at home. Also, improved walking provides preliminary evidence of game-based priming to be beneficial as a telerehabilitation strategy for stroke motor recovery.

Evaluation of Artificial Intelligence-Based Intraoperative Guidance Tools for Phacoemulsification Cataract Surgery.

IMPORTANCE: Complications that arise from phacoemulsification procedures can lead to worse visual outcomes. Real-time image processing with artificial intelligence tools can extract data to deliver surgical guidance, potentially enhancing the surgical environment. OBJECTIVE: To evaluate the ability of a deep neural network to track the pupil, identify the surgical phase, and activate specific computer vision tools to aid the surgeon during phacoemulsification cataract surgery by providing visual feedback in real time. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study evaluated deidentified surgical videos of phacoemulsification cataract operations performed by faculty and trainee surgeons in a university-based ophthalmology department between July 1, 2020, and January 1, 2021, in a population-based cohort of patients. EXPOSURES: A region-based convolutional neural network was used to receive frames from the video source and, in real time, locate the pupil and in parallel identify the surgical phase being performed. Computer vision-based algorithms were applied according to the phase identified, providing visual feedback to the surgeon. MAIN OUTCOMES AND MEASURES: Outcomes were area under the receiver operator characteristic curve and area under the precision-recall curve for surgical phase classification and Dice score (harmonic mean of the precision and recall [sensitivity]) for detection of the pupil boundary. Network performance was assessed as video output in frames per second. A usability survey was administered to volunteer cataract surgeons previously unfamiliar with the platform. RESULTS: The region-based convolutional neural network model achieved area under the receiver operating characteristic curve values of 0.996 for capsulorhexis, 0.972 for phacoemulsification, 0.997 for cortex removal, and 0.880 for idle phase recognition. The final algorithm reached a Dice score of 90.23% for pupil segmentation and a mean (SD) processing speed of 97 (34) frames per second. Among the 11 cataract surgeons surveyed, 8 (72%) were mostly or extremely likely to use the current platform during surgery for complex cataract. CONCLUSIONS AND RELEVANCE: A computer vision approach using deep neural networks was able to pupil track, identify the surgical phase being executed, and activate surgical guidance tools. These results suggest that an artificial intelligence-based surgical guidance platform has the potential to enhance the surgeon experience in phacoemulsification cataract surgery. This proof-of-concept investigation suggests that a pipeline from a surgical microscope could be integrated with neural networks and computer vision tools to provide surgical guidance in real time.

CathSym: Device and Method to Bring Haptic Feedback to Urinary Catheterization Training.

Urinary catheterization is one of the most widely taught procedures in the medical field. Current simulation-based training methods allow the students to be trained on non-realistic mannequins that do not adequately develop their psychomotor skills. This lack of proper training translates into increased likelihood of the medical professional causing damage to the patients' urethra in the form of false passages when faced with a difficult catheterization. The leading cause of this damage is the overuse of force that diverts the catheter head into the soft tissue. With the emergence of haptic feedback and virtual training into the medical field, we aimed to design and build a novel haptics-based mixed reality simulation trainer for teaching urinary catheterization. We developed a software system accompanied with a customized haptic feedback device to help the user train in various catheterization scenarios to gain experience for improving their psychomotor skills and teach them to navigate blockages and other anatomies in the urethra. Our simulation platform has the potential to adequately provde the trainees with realistic force and visual feedback that are representative of what the user might experience in real world Foley catheterization.

Psychomotor skills development for Veress needle placement using a virtual reality and haptics-based simulator.

PURPOSE: Veress needle (VN) insertion, if not correctly performed, could cause severe injuries to intra-abdominal organs and vessels. Therefore, cognitive and psychomotor skills training is needed. Virtual reality (VR) and haptic technologies have the potential to offer realistic simulations. METHODS: We developed a novel VR and haptic surgical simulator for VN insertion to teach trainees how to correctly puncture the abdominal wall, experiencing realistic tactile sensations throughout the simulation. The simulator allows for both procedural and realistic training. We released two different versions: the first using the OpenHaptics[Formula: see text] (OH) Toolkit and the second exploiting CHAI3D. We evaluated the learning effect using different performance indexes (time to perform the procedure, error in insertion angle, number of undesired contacts with organs) in an insertion task for both experienced urologists and students. RESULTS: A general improvement of the chosen performance indexes was registered in the second repetition of the task for both groups. From the questionnaires, the simulator leveraging OH provides the trainee with a more precise haptic feedback, whereas the one exploiting CHAI3D allows them to perform the procedure more easily thanks to the better visualization of the virtual environment. The results proved that the participants appreciated both implementations, and the System Usability Scale (SUS) test resulted in a "good" usability. CONCLUSION: The haptics-based and VR simulator has shown the potential to be an important resource for the basic urological training in obtaining the pneumoperitoneum and improving the acquisition of the necessary psychomotor skills, allowing for extended and more effective training without compromising patient safety.

Game-based movement facilitates acute priming effect in stroke.

OBJECTIVE: Cortical priming is an emerging strategy to enhance motor recovery after stroke, however, limited information exists on the neuromodulatory effects of lower limb movement-based priming to facilitate corticomotor excitability after stroke. In this study, we investigated the feasibility and effectiveness of game-based ankle movement priming using the DIG-I-PRIME™ on corticomotor excitability and motor performance in chronic stroke survivors. METHODS: Nineteen stroke survivors participated in a 20-min session of game-based priming. A period of rest served as a control for the priming condition. Transcranial magnetic stimulation (TMS) was used to measure corticomotor excitability of the paretic and non-paretic tibialis anterior (TA) muscle representations. Motor performance was quantified by assessing the accuracy to track a sinusoidal target wave with paretic dorsiflexion and plantarflexion. RESULTS: Ipsilesional corticomotor excitability increased by 25% after game-based movement priming (p = 0.02) while changes were not observed after the control condition. No change in motor performance was noted. CONCLUSION: Game-based ankle movement priming demonstrated a significant acute priming effect on the ipsilesional lower limb M1. These data provide preliminary evidence for the potential benefits of game-based priming to promote functional recovery after stroke.

Design of a navigational catheter system for the targeted delivery of therapeutics within the suprachoroidal space.

Diseases of the posterior segment of the eye are common causes of blindness and can be difficult to treat due to their location. Recently, there has been increased interest in the use of the suprachoroidal space to deliver therapeutics to the posterior segment. This space is accessible through a trans-scleral approach and blunt dissection of the adjacent scleral and choroidal tissues. However, despite recent commercial interest, there are few tools designed specifically to provide targeted delivery of therapeutics to a localised region within the suprachoroidal space. Therefore, we designed and prototyped a novel navigational catheter system for the targeted delivery of payloads within the suprachoroidal space. The system consists of a customised catheter tip designed to minimise blunt dissection stresses on neighbouring tissues, a mechanism for controlled catheter navigation, and a method for targeted delivery of large payloads. A customised in vitro model of the eye was also designed to visually demonstrate the capability of the catheter system to controllably navigate within the suprachoroidal space and deliver a targeted payload. This system can enable the delivery of large therapeutic payloads to the eye for the treatment of posterior eye diseases, thereby impacting the development and availability of vision-saving treatments.

Autonomous image segmentation and identification of anatomical landmarks from lumbar spine intraoperative computed tomography scans using machine learning: A validation study.

PURPOSE: Machine-learning algorithms are a subset of artificial intelligence that have proven to enhance analytics in medicine across various platforms. Spine surgery has the potential to benefit from improved hardware placement utilizing algorithms that autonomously and accurately measure pedicle and vertebral body anatomy. The purpose of this study was to assess the accuracy of an autonomous convolutional neural network (CNN) in measuring vertebral body anatomy utilizing clinical lumbar computed tomography (CT) scans and automatically segment vertebral body anatomy. METHODS: The CNN was trained utilizing 8000 manually segmented CT slices from 15 cadaveric specimens and 30 adult diagnostic scans. Validation was performed with twenty randomly selected patient datasets. Anatomic landmarks that were segmented included the pedicle, vertebral body, spinous process, transverse process, facet joint, and lamina. Morphometric measurement of the vertebral body was compared between manual measurements and automatic measurements. RESULTS: Automatic segmentation was found to have a mean accuracy ranging from 96.38% to 98.96%. Coaxial distance from the lamina to the anterior cortex was 99.10% with pedicle angulation error of 3.47%. CONCLUSION: The CNN algorithm tested in this study provides an accurate means to automatically identify the vertebral body anatomy and provide measurements for implants and placement trajectories.

Augmented reality and artificial intelligence-assisted surgical navigation: Technique and cadaveric feasibility study.

PURPOSE: Augmented reality-based image overlay of virtual bony spine anatomy can be projected onto real spinal anatomy using computer tomography-generated DICOM images acquired intraoperatively. The aim of the study was to develop a technique and assess the accuracy and feasibility of lumbar vertebrae pedicle instrumentation using augmented reality-assisted surgical navigation. SUBJECTS AND METHODS: An augmented reality and artificial intelligence (ARAI)-assisted surgical navigation system was developed. The system consists of a display system which hovers over the surgical field and projects three-dimensional (3D) medical images corresponding with the patient's anatomy. The system was registered to the cadaveric spine using an optical tracker and arrays with reflective markers. The virtual image overlay from the ARAI system was compared to 3D generated images from intraoperative scans and used to percutaneously navigate a probe to the cortex at the corresponding pedicle starting point. Intraoperative scan was used to confirm the probe position. Virtual probe placement was compared to the actual probe position in the bone to determine the accuracy of the navigation system. RESULTS: Four cadaveric thoracolumbar spines were used. The navigated probes were correctly placed in all attempted levels (n = 24 levels), defined as Zdichavsky type 1a, Ravi type I, and Gertzbein type 0. The virtual overlay image corresponded to the 3D generated image in all the tested levels. CONCLUSIONS: The ARAI surgical navigation system correctly and accurately identified the starting points at all the attempted levels. The virtual anatomy image overlay precisely corresponded to the actual anatomy in all the tested scenarios. This technology may lead more uniform outcomes between surgeons and decrease minimally invasive spine surgery learning curves.

Filling the gap between the OR and virtual simulation: a European study on a basic neurosurgical procedure.

BACKGROUND: Currently available simulators are supposed to allow young neurosurgeons to hone their technical skills in a safe environment, without causing any unnecessary harm to their patients caused by their inexperience. For this training method to be largely accepted in neurosurgery, it is necessary to prove simulation efficacy by means of large-scale clinical validation studies. METHODS: We correlated and analysed the performance at a simulator and the actual operative skills of different neurosurgeons (construct validity). We conducted a study involving 92 residents and attending neurosurgeons from different European Centres; each participant had to perform a virtual task, namely the placement of an external ventricular drain (EVD) at a neurosurgical simulator (ImmersiveTouch). The number of attempts needed to reach the ventricles and the accuracy in positioning the catheter were assessed. RESULTS: Data suggests a positive correlation between subjects who placed more EVDs in the previous year and those who get better scores at the simulator (p = .008) (fewer attempts and better surgical accuracy). The number of attempts to reach the ventricle was also analysed; senior residents needed fewer attempts (mean = 2.26; SD = 1.11) than junior residents (mean = 3.12; SD = 1.05) (p = .007) and staff neurosurgeons (mean = 2.89, SD = 1.23). Scoring results were compared by using the Fisher's test, for the analysis of the variances, and the Student's T test. Surprisingly, having a wider surgical experience overall does not correlate with the best performance at the simulator. CONCLUSION: The performance of an EVD placement on a simulator correlates with the density of the neurosurgical experience for that specific task performed in the OR, suggesting that simulators are able to differentiate neurosurgeons according to their surgical ability. Namely this suggests that the simulation performance reflects the surgeons' consistency in placing EVDs in the last year.

Evaluation of Sensory and Motor Skills in Neurosurgery Applicants Using a Virtual Reality Neurosurgical Simulator: The Sensory-Motor Quotient.

OBJECTIVE: Manual skill is an important attribute for any surgeon. Current methods to evaluate sensory-motor skills in neurosurgical residency applicants are limited. We aim to develop an objective multifaceted measure of sensory-motor skills using a virtual reality surgical simulator. DESIGN: A set of 3 tests of sensory-motor function was performed using a 3-dimensional surgical simulator with head and arm tracking, collocalization, and haptic feedback. (1) Trajectory planning: virtual reality drilling of a pedicle. Entry point, target point, and trajectory were scored-evaluating spatial memory and orientation. (2) Motor planning: sequence, timing, and precision: hemostasis in a postresection cavity in the brain. (3) Haptic perception: touching virtual spheres to determine which is softest of the group, with progressive difficulty. Results were analyzed individually and for a combined score of all the tasks. SETTING: The University of Chicago Hospital's tertiary care academic center. PARTICIPANTS: A total of 95 consecutive applicants interviewed at a neurosurgery residency program over 2 years were offered anonymous participation in the study; in 2 cohorts, 36 participants in year 1 and 27 participants in year 2 (validation cohort) agreed and completed all the tasks. We also tested 10 first-year medical students and 4 first- and second-year neurosurgery residents. RESULTS: A cumulative score was generated from the 3 tests. The mean score was 14.47 (standard deviation = 4.37), median score was 13.42, best score was 8.41, and worst score was 30.26. Separate analysis of applicants from each of 2 years yielded nearly identical results. Residents tended to cluster on the better performance side, and first-year students were not different from applicants. CONCLUSIONS: (1) Our cumulative score measures sensory-motor skills in an objective and reproducible way. (2) Better performance by residents hints at validity for neurosurgery. (3) We were able to demonstrate good psychometric qualities and generate a proposed sensory-motor quotient distribution in our tested population.

Usefulness of a Virtual Reality Percutaneous Trigeminal Rhizotomy Simulator in Neurosurgical Training.

BACKGROUND: Simulation-based training may be incorporated into neurosurgery in the future. OBJECTIVE: To assess the usefulness of a novel haptics-based virtual reality percutaneous trigeminal rhizotomy simulator. METHODS: A real-time augmented reality simulator for percutaneous trigeminal rhizotomy was developed using the ImmersiveTouch platform. Ninety-two neurosurgery residents tested the simulator at American Association of Neurological Surgeons Top Gun 2014. Postgraduate year (PGY), number of fluoroscopy shots, the distance from the ideal entry point, and the distance from the ideal target were recorded by the system during each simulation session. Final performance score was calculated considering the number of fluoroscopy shots and distances from entry and target points (a lower score is better). The impact of PGY level on residents' performance was analyzed. RESULTS: Seventy-one residents provided their PGY-level and simulator performance data; 38% were senior residents and 62% were junior residents. The mean distance from the entry point (9.4 mm vs 12.6 mm, P = .01), the distance from the target (12.0 mm vs 15.2 mm, P = .16), and final score (31.1 vs 37.7, P = .02) were lower in senior than in junior residents. The mean number of fluoroscopy shots (9.8 vs 10.0, P = .88) was similar in these 2 groups. Linear regression analysis showed that increasing PGY level is significantly associated with a decreased distance from the ideal entry point (P = .001), a shorter distance from target (P = .05), a better final score (P = .007), but not number of fluoroscopy shots (P = .52). CONCLUSION: Because technical performance of percutaneous rhizotomy increases with training, we proposed that the skills in performing the procedure in our virtual reality model would also increase with PGY level, if our simulator models the actual procedure. Our results confirm this hypothesis and demonstrate construct validity.

The use of a virtual reality surgical simulator for cataract surgical skill assessment with 6 months of intervening operating room experience.

PURPOSE: To evaluate a haptic-based simulator, MicroVisTouch™, as an assessment tool for capsulorhexis performance in cataract surgery. The study is a prospective, unmasked, nonrandomized dual academic institution study conducted at the Wilmer Eye Institute at Johns Hopkins Medical Center (Baltimore, MD, USA) and King Khaled Eye Specialist Hospital (Riyadh, Saudi Arabia). METHODS: This prospective study evaluated capsulorhexis simulator performance in 78 ophthalmology residents in the US and Saudi Arabia in the first round of testing and 40 residents in a second round for follow-up. RESULTS: Four variables (circularity, accuracy, fluency, and overall) were tested by the simulator and graded on a 0-100 scale. Circularity (42%), accuracy (55%), and fluency (3%) were compiled to give an overall score. Capsulorhexis performance was retested in the original cohort 6 months after baseline assessment. Average scores in all measured metrics demonstrated statistically significant improvement (except for circularity, which trended toward improvement) after baseline assessment. A reduction in standard deviation and improvement in process capability indices over the 6-month period was also observed. CONCLUSION: An interval objective improvement in capsulorhexis skill on a haptic-enabled cataract surgery simulator was associated with intervening operating room experience. Further work investigating the role of formalized simulator training programs requiring independent simulator use must be studied to determine its usefulness as an evaluation tool.

Virtual reality cerebral aneurysm clipping simulation with real-time haptic feedback.

BACKGROUND: With the decrease in the number of cerebral aneurysms treated surgically and the increase of complexity of those treated surgically, there is a need for simulation-based tools to teach future neurosurgeons the operative techniques of aneurysm clipping. OBJECTIVE: To develop and evaluate the usefulness of a new haptic-based virtual reality simulator in the training of neurosurgical residents. METHODS: A real-time sensory haptic feedback virtual reality aneurysm clipping simulator was developed using the ImmersiveTouch platform. A prototype middle cerebral artery aneurysm simulation was created from a computed tomographic angiogram. Aneurysm and vessel volume deformation and haptic feedback are provided in a 3-dimensional immersive virtual reality environment. Intraoperative aneurysm rupture was also simulated. Seventeen neurosurgery residents from 3 residency programs tested the simulator and provided feedback on its usefulness and resemblance to real aneurysm clipping surgery. RESULTS: Residents thought that the simulation would be useful in preparing for real-life surgery. About two-thirds of the residents thought that the 3-dimensional immersive anatomic details provided a close resemblance to real operative anatomy and accurate guidance for deciding surgical approaches. They thought the simulation was useful for preoperative surgical rehearsal and neurosurgical training. A third of the residents thought that the technology in its current form provided realistic haptic feedback for aneurysm surgery. CONCLUSION: Neurosurgical residents thought that the novel immersive VR simulator is helpful in their training, especially because they do not get a chance to perform aneurysm clippings until late in their residency programs.

Neurosurgical tactile discrimination training with haptic-based virtual reality simulation.

OBJECTIVE: To determine if a computer-based simulation with haptic technology can help surgical trainees improve tactile discrimination using surgical instruments. MATERIAL AND METHODS: Twenty junior medical students participated in the study and were randomized into two groups. Subjects in Group A participated in virtual simulation training using the ImmersiveTouch simulator (ImmersiveTouch, Inc., Chicago, IL, USA) that required differentiating the firmness of virtual spheres using tactile and kinesthetic sensation via haptic technology. Subjects in Group B did not undergo any training. With their visual fields obscured, subjects in both groups were then evaluated on their ability to use the suction and bipolar instruments to find six elastothane objects with areas ranging from 1.5 to 3.5 cm2 embedded in a urethane foam brain cavity model while relying on tactile and kinesthetic sensation only. RESULTS: A total of 73.3% of the subjects in Group A (simulation training) were able to find the brain cavity objects in comparison to 53.3% of the subjects in Group B (no training) (P  =  0.0183). There was a statistically significant difference in the total number of Group A subjects able to find smaller brain cavity objects (size ≤ 2.5 cm2) compared to that in Group B (72.5 vs. 40%, P  =  0.0032). On the other hand, no significant difference in the number of subjects able to detect larger objects (size ≧ 3 cm2) was found between Groups A and B (75 vs. 80%, P  =  0.7747). CONCLUSION: Virtual computer-based simulators with integrated haptic technology may improve tactile discrimination required for microsurgical technique.

Virtual reality spine surgery simulation: an empirical study of its usefulness.

OBJECTIVE: This study explores the usefulness of virtual simulation training for learning to place pedicle screws in the lumbar spine. METHODS: Twenty-six senior medical students anonymously participated and were randomized into two groups (A = no simulation; B = simulation). Both groups were given 15 minutes to place two pedicle screws in a sawbones model. Students in Group A underwent traditional visual/verbal instruction whereas students in Group B underwent training on pedicle screw placement in the ImmersiveTouch simulator. The students in both groups then placed two pedicle screws each in a lumbar sawbones models that underwent triplanar thin slice computerized tomography and subsequent analysis based on coronal entry point, axial and sagittal deviations, length error, and pedicle breach. The average number of errors per screw was calculated for each group. Semi-parametric regression analysis for clustered data was used with generalized estimating equations accommodating a negative binomial distribution to determine any statistical difference of significance. RESULTS: A total of 52 pedicle screws were analyzed. The reduction in the average number of errors per screw after a single session of simulation training was 53.7% (P  =  0.0067). The average number of errors per screw in the simulation group was 0.96 versus 2.08 in the non-simulation group. The simulation group outperformed the non-simulation group in all variables measured. The three most benefited measured variables were length error (86.7%), coronal error (71.4%), and pedicle breach (66.7%). CONCLUSIONS: Computer-based simulation appears to be a valuable teaching tool for non-experts in a highly technical procedural task such as pedicle screw placement that involves sequential learning, depth perception, and understanding triplanar anatomy.

Virtual reality simulator for vitreoretinal surgery using integrated OCT data.

Operative practice using surgical simulators has become a part of training in many surgical specialties, including ophthalmology. We introduce a virtual reality retina surgery simulator capable of integrating optical coherence tomography (OCT) scans from real patients for practicing vitreoretinal surgery using different pathologic scenarios.

A novel virtual reality simulation for hemostasis in a brain surgical cavity: perceived utility for visuomotor skills in current and aspiring neurosurgery residents.

OBJECTIVE: To understand the perceived utility of a novel simulator to improve operative skill, eye-hand coordination, and depth perception. METHODS: We used the ImmersiveTouch simulation platform (ImmersiveTouch, Inc., Chicago, Illinois, USA) in two U.S. Accreditation Council for Graduate Medical Education-accredited neurosurgical training programs: the University of Chicago and the University of Texas Medical Branch. A total of 54 trainees participated in the study, which consisted of 14 residents (group A), 20 senior medical students who were neurosurgery candidates (group B), and 20 junior medical students (group C). The participants performed a simulation task that established bipolar hemostasis in a virtual brain cavity and provided qualitative feedback regarding perceived benefits in eye-hand coordination, depth perception, and potential to assist in improving operating skills. RESULTS: The perceived ability of the simulator to positively influence skills judged by the three groups: group A, residents; group B, senior medical students; and group C, junior medical students was, respectively, 86%, 100%, and 100% for eye-hand coordination; 86%, 100%, and 95% for depth perception; and 79%, 100%, and 100% for surgical skills in the operating room. From all groups, 96.2% found the simulation somewhat or very useful to improve eye-hand coordination, and 94% considered it beneficial to improve depth perception and operating room skills. CONCLUSION: This simulation module may be suitable for resident training, as well as for the development of career interest and skill acquisition; however, validation for this type of simulation needs to be further developed.

Sensory and motor skill testing in neurosurgery applicants: a pilot study using a virtual reality haptic neurosurgical simulator.

BACKGROUND: Manual skill is important for surgeons, but current methods to evaluate sensory-motor skills in applicants to a surgical residency are limited. OBJECTIVE: To develop a method of testing sensory-motor skill using objective and reproducible virtual reality simulation. METHODS: We designed a set of tests on a 3-dimensional surgical simulator with head and arm tracking, colocalization, and haptic feedback: (1) "trajectory planning in a simulated vertebra," ie, 3-dimensional memory and orientation; "hemostasis in the brain," ie, motor planning, sequence, timing, and precision; and "choose the softest object," ie, haptic perception. We also derived a weighted combined score for all tasks. RESULTS: Of the 55 consecutive applicants to a neurosurgery residency approached, 46 performed at least 1 task, and 36 performed all tasks. For the trajectory planning task, the distance from target ranged from 3 to 30 mm, with 25 of 36 in the 6- to 18-mm range. In the motor planning test, the duration between cauterization attempts ranged between 5 and 22.5 seconds, peaking at 10 to 12.5 seconds in 15 of 36 participants. In the haptic perception test, linear regression demonstrated increased variability in performance with increasing difficulty of task (R = 0.6281). In all tests, performance followed a roughly bell-shaped curve. The combined weighted score of all tests demonstrated a better bell curve distribution, with scores ranging from 0.275 to 0.71 (mean, 0.47; median, 0.4775; SD, 0.1174). CONCLUSION: Our study represents a first step in the direction of an objective, standard, computer-scored test of motor and haptic ability.

Practice on an augmented reality/haptic simulator and library of virtual brains improves residents' ability to perform a ventriculostomy.

INTRODUCTION: Ventriculostomy is a neurosurgical procedure for providing therapeutic cerebrospinal fluid drainage. Complications may arise during repeated attempts at placing the catheter in the ventricle. We studied the impact of simulation-based practice with a library of virtual brains on neurosurgery residents' performance in simulated and live surgical ventriculostomies. METHODS: Using computed tomographic scans of actual patients, we developed a library of 15 virtual brains for the ImmersiveTouch system, a head- and hand-tracked augmented reality and haptic simulator. The virtual brains represent a range of anatomies including normal, shifted, and compressed ventricles. Neurosurgery residents participated in individual simulator practice on the library of brains including visualizing the 3-dimensional location of the catheter within the brain immediately after each insertion. Performance of participants on novel brains in the simulator and during actual surgery before and after intervention was analyzed using generalized linear mixed models. RESULTS: Simulator cannulation success rates increased after intervention, and live procedure outcomes showed improvement in the rate of successful cannulation on the first pass. However, the incidence of deeper, contralateral (simulator) and third-ventricle (live) placements increased after intervention. Residents reported that simulations were realistic and helpful in improving procedural skills such as aiming the probe, sensing the pressure change when entering the ventricle, and estimating how far the catheter should be advanced within the ventricle. CONCLUSIONS: Simulator practice with a library of virtual brains representing a range of anatomies and difficulty levels may improve performance, potentially decreasing complications due to inexpert technique.