R2DRV: study protocol for longitudinal assessment of driving after mild TBI in young drivers.

BACKGROUND: Mild traumatic brain injury (mTBI) and traffic-related injuries are two major public health problems disproportionately affecting young people. Young drivers, whose driving skills are still developing, are particularly vulnerable to impaired driving due to brain injuries. Despite this, there is a paucity of research on how mTBI impacts driving and when it is safe to return to drive after an mTBI. This paper describes the protocol of the study, R2DRV, Longitudinal Assessment of Driving After Mild TBI in Young Drivers, which examines the trajectory of simulated driving performance and self-reported driving behaviors from acutely post-injury to symptom resolution among young drivers with mTBI compared to matched healthy drivers. Additionally, this study investigates the associations of acute post-injury neurocognitive function and cognitive load with driving among young drivers with and without mTBI. METHODS: A total of 200 young drivers (ages 16 to 24) are enrolled from two study sites, including 100 (50 per site) with a physician-confirmed isolated mTBI, along with 100 (50 per site) healthy drivers without a history of TBI matched 1:1 for age, sex, driving experience, and athlete status. The study assesses primary driving outcomes using two approaches: (1) high-fidelity driving simulators to evaluate driving performance across four experimental study conditions at multiple time points (within 96 h of injury and weekly until symptom resolution or 8 weeks post-injury); (2) daily self-report surveys on real-world driving behaviors completed by all participants. DISCUSSION: This study will fill critical knowledge gaps by longitudinally assessing driving performance and behaviors in young drivers with mTBI, as compared to matched healthy drivers, from acutely post-injury to symptom resolution. The research strategy enables evaluating how increased cognitive load may exacerbate the effects of mTBI on driving, and how post-mTBI neurocognitive deficits may impact the driving ability of young drivers. Findings will be shared through scientific conferences, peer-reviewed journals, and media outreach to care providers and the public.

Driving performance acutely after mTBI among young drivers.

OBJECTIVE: Mild traumatic brain injury (mTBI) can impair executive function, learning, and memory, which can negatively impact driving ability. However, little is known how the driving performance of young drivers may be impacted acutely after mTBI. This study aimed to evaluate simulated driving within 96 h of mTBI among young drivers as compared to matched healthy controls, and assess the effects of increased cognitive load on driving performance. METHODS: Injured young drivers ages 16 to 24 with physician-confirmed mTBI were enrolled from two sites (University of Alabama at Birmingham and Ohio State University) and completed the assessment on a high-fidelity driving simulator within 96 h of injury. Matched healthy controls were young drivers without mTBIs matched with an index mTBI by age, sex, athlete status, and driving experience. Participants drove four scenarios in a 2x2 design: with/without cognitive load and with/without critical events. Linear mixed models were used to compare the driving outcomes between mTBI drivers and healthy controls. RESULTS: A total of 38 participants were included, with 25 cases and 13 controls. Standard deviation of lateral position, following distance and reaction time were analyzed. The preliminary findings indicated that mTBI drivers tended to maintain more distance to the car in front of them than healthy controls. High cognitive load was associated with slower reaction time regardless of TBI status. CONCLUSIONS: This study is the first to assess simulated driving performance among young drivers with mTBI acutely post-injury. The findings will have important clinical implications on when young drivers may return to driver post-mTBI and at what conditions. Additional research is warranted to confirm these results.

Driving performance and road sign identification by multifocal contact lens wearers in a driving simulator.

PURPOSE: The purpose of this study was to compare sign identification distances and driving performance metrics in presbyopic participants while wearing multifocal contact lenses (MFCL) and while wearing progressive addition lens (PAL) spectacles. METHODS: 19 presbyopic participants completed PAL spectacle assessments and contact lens fitting and follow up visits before driving assessments began. These assessments occurred in a simulator equipped with a full-sized sedan on a motion platform and a 260 degree screen. Participants completed the driving task with PAL and with MFCL. Participants followed a lead car and identified signs at various distances from the road. For the two wearing conditions, comparisons of the distance along the road at which signs were identified were made using repeated measures ANOVA. Paired t-tests were used to compare driving performance for the two conditions. RESULTS: There was no statistical difference in sign identification distance between PAL and MFLC for signs 32.0 m from the road side of the road (182 ± 46 m for MFCL; 205 ± 45 m for PAL; P = 0.07) or 51.4 m from the side of the road (204 ± 43 m for MFCL; 216 ± 36 m for PAL; P = 0.3). Only signs 70.2 m from the roadside showed a significant difference (207 ± 42 m with MFCL; 232 ± 39 m with PAL; P = 0.01), All distances were greater than those required to safely stop a vehicle. There were no significant differences in the driving performance metrics between the refractive corrections. CONCLUSION: Driving performance metrics were similar for MFCL and PAL spectacles. Sign identification distances with both eyewear types were well within the distances required for safe vehicle stopping.

Measuring the perception of aggression in driving behavior.

The study of aggressive driving is an important step in the reduction of (often fatal) crashes due to this behavior. However, even though various measures of aggressive driver behavior have been proposed, a more thorough examination of what the driving public perceives as aggressive driving behavior can be performed. A nationally representative sample of 198 American adults saw and rated the aggressiveness of various driving behaviors in videos. The videos were shown from a first-, second-, or third-person perspective. Some videos depicted close following, varying in speed and distance from the car ahead. Participants also saw illegal passing videos and collision or near collision videos. A number of variables that might influence judgments of aggressive driving were included as controls (i.e., trait anger, aggressive and prosocial driving attitudes, driving experience). Following other drivers closely was rated as aggressive, especially when viewed from a third-person perspective. Illegal passes were viewed as more aggressive than speeding. Faster speeds didn't increase aggressive ratings much, regardless of perspective. Aggressiveness ratings were especially high for acts that could be considered "road rage" (i.e., hitting or nearly hitting vehicles, cyclists, and pedestrians). People high in trait anger have a bias to view many driving behaviors as intentionally aggressive.

Standard Setting of Competency in Mastoidectomy for the Cross-Institutional Mastoidectomy Assessment Tool.

OBJECTIVE: Competency-based surgical training involves progressive autonomy given to the trainee. This requires systematic and evidence-based assessment with well-defined standards of proficiency. The objective of this study is to develop standards for the cross-institutional mastoidectomy assessment tool to inform decisions regarding whether a resident demonstrates sufficient skill to perform a mastoidectomy with or without supervision. METHODS: A panel of fellowship-trained content experts in mastoidectomy was surveyed in relation to the 16 items of the assessment tool to determine the skills needed for supervised and unsupervised surgery. We examined the consensus score to investigate the degree of agreement among respondents for each survey item as well as additional analyses to determine whether the reported skill level required for each survey item was significantly different for the supervised versus unsupervised level. RESULTS: Ten panelists representing different US training programs responded. There was considerable consensus on cut-off scores for each item and trainee level between panelists, with moderate (0.62) to very high (0.95) consensus scores depending on assessment item. Further analyses demonstrated that the difference between supervised and unsupervised skill levels was significantly meaningful for all items. Finally, minimum-passing scores for each item was established. CONCLUSION: We defined performance standards for the cross-institutional mastoidectomy assessment tool using the Angoff method. These cut-off scores that can be used to determine when trainees can progress from performance under supervision to performance without supervision. This can be used to guide training in a competency-based training curriculum.

A review of simulation applications in temporal bone surgery.

BACKGROUND: Temporal bone surgery is a technically challenging and high-risk procedure in an anatomically complex area. Safe temporal bone surgery emphasizes a consummate anatomic understanding and technique development that requires the guidance of an experienced otologic surgeon and years of practice. Temporal bone simulation can augment otologic surgical training and enable rehearsal of surgical procedures. OBJECTIVES: The purpose of this article is to provide an updated review of temporal bone simulation platforms and their uses. DATA SOURCES: PubMed literature search. Search terms included temporal bone, temporal bone simulation, virtual reality (VR), and presurgical planning and rehearsal. DISCUSSION: Various simulation platforms such as cadaveric bone, three-dimensional (3D) printed models, and VR simulation have been used for temporal bone surgery training. However, each simulation method has its drawbacks. There is a need to improve upon current simulation platforms to enhance surgical training and skills assessment, as well as a need to explore other clinically significant applications of simulation, such as preoperative planning and rehearsal, in otologic surgery. CONCLUSIONS: There is no replacement for actual surgical experience, but high-fidelity temporal bone models such as those produced with 3D printing and computer simulation have emerged as promising tools in otolaryngologic surgery. Improvements in the fidelity of both 3D printed and VR simulators as well as integration of a standardized assessment format would allow for an expansion in the use of these simulation platforms in training and assessment. LEVEL OF EVIDENCE: 5.

Atlas-based segmentation of temporal bone surface structures.

PURPOSE: To develop a time-efficient automated segmentation approach that could identify surface structures on the temporal bone for use in surgical simulation software and preoperative surgical training. METHODS: An atlas-based segmentation approach was developed to segment the tegmen, sigmoid sulcus, exterior auditory canal, interior auditory canal, and posterior canal wall in normal temporal bone CT images. This approach was tested in images of 20 cadaver bones (10 left, 10 right). The results of the automated segmentation were compared to manual segmentation using quantitative metrics of similarity, Mahalanobis distance, average Hausdorff distance, and volume similarity. RESULTS: The Mahalanobis distance was less than 0.232 mm for all structures. The average Hausdorff distance was less than 0.464 mm for all structures except the posterior canal wall and external auditory canal for the right bones. Volume similarity was 0.80 or greater for all structures except the sigmoid sulcus that was 0.75 for both left and right bones. Visually, the segmented structures were accurate and similar to that manually traced by an expert observer. CONCLUSIONS: An atlas-based approach using a deformable registration of a Gaussian-smoothed temporal bone image and refinements using surface landmarks was successful in segmenting surface structures of temporal bone anatomy for use in pre-surgical planning and training.

Cross-Institutional Evaluation of a Mastoidectomy Assessment Instrument.

OBJECTIVE: The objective of this work is to obtain validity evidence for an evaluation instrument used to assess the performance level of a mastoidectomy. The instrument has been previously described and had been formulated by a multi-institutional consortium. DESIGN: Mastoidectomies were performed on a virtual temporal bone system and then rated by experts using a previously described 15 element task-based checklist. Based on the results, a second, similar checklist was created and a second round of rating was performed. SETTING: Twelve otolaryngological surgical training programs in the United States. PARTICIPANTS: In all, 65 mastoidectomy performances were evaluated coming from 37 individuals with a variety of temporal bone dissection experience, from medical students to attending physicians. Raters were attending surgeons from 12 different institutions. RESULTS: Intraclass correlation scores varied greatly between items in the checklist with some being low and some being high. Percentage agreement scores were similar to previous rating instruments. There is strong evidence that a high score on the task-based checklist is necessary for a rater to consider a mastoidectomy to be performed at the level of an expert but a high score is not a sufficient condition. CONCLUSIONS: Rewording of the instrument items to focus on safety does not result in increased reliability of the instrument. The strong result of the Necessary Condition Analysis suggests that going beyond simple correlation measures can give extra insight into grading results. Additionally, we suggest using a multiple point scale instead of a binary pass/fail question combined with descriptive mastery levels.

Atlas-Based Segmentation of Temporal Bone Anatomy.

PURPOSE: To develop a time-efficient automated segmentation approach that could identify critical structures in the temporal bone for visual enhancement and use in surgical simulation software. METHODS: An atlas-based segmentation approach was developed to segment the cochlea, ossicles, semicircular canals (SCCs), and facial nerve in normal temporal bone CT images. This approach was tested in images of 26 cadaver bones (13 left, 13 right). The results of the automated segmentation were compared to manual segmentation visually and using DICE metric, average Hausdorff distance, and volume similarity. RESULTS: The DICE metrics were greater than 0.8 for the cochlea, malleus, incus, and the SCCs combined. It was slightly lower for the facial nerve. The average Hausdorff distance was less than one voxel for all structures, and the volume similarity was 0.86 or greater for all structures except the stapes. CONCLUSIONS: The atlas-based approach with rigid body registration of the otic capsule was successful in segmenting critical structures of temporal bone anatomy for use in surgical simulation software.

Multi-Institutional Development of a Mastoidectomy Performance Evaluation Instrument.

OBJECTIVE: A method for rating surgical performance of a mastoidectomy procedure that is shown to apply universally across teaching institutions has not yet been devised. This work describes the development of a rating instrument created from a multi-institutional consortium. DESIGN: Using a participatory design and a modified Delphi approach, a multi-institutional group of expert otologists constructed a 15-element task-based checklist for evaluating mastoidectomy performance. This instrument was further refined into a 14-element checklist focusing on the concept of safety after using it to rate a large and varied population of performances. SETTING: Twelve otolaryngological surgical training programs in the United States. PARTICIPANTS: A total of 14 surgeons from 12 different institutions took part in the construction of the instrument. RESULTS: By using 14 experts from 12 different institutions and a literature review, individual metrics were identified, rated as to the level of importance and operationally defined to create a rating scale for mastoidectomy performance. Initial use of the rating scale showed modest rater agreement. The operational definitions of individual metrics were modified to emphasize "safe" as opposed to "proper" technique. A second rating instrument was developed based on this feedback. CONCLUSIONS: Using a consensus-building approach with multiple rounds of communication between experts is a feasible way to construct a rating instrument for mastoidectomy. Expert opinion alone using a Delphi method provides face and content validity evidence, however, this is not sufficient to develop a universally acceptable rating instrument. A continued process of development and experimentation to demonstrate evidence for reliability and validity making use of a large population of raters and performances is necessary to achieve universal acceptance.

Expert subjective comparison of haptic models for bone-drill interaction.

PURPOSE: A haptic algorithm to simulate the interaction between a surgical drill and bone using a constraint-based algorithm has been previously demonstrated. However, there has been no blinded study to determine whether this algorithm is preferred by professionals who commonly use this type of system METHODS: Fourteen otologic surgeons were presented with a spring-damper model and a constraint-based model of drill-bone interaction rendered on a low-cost haptic device with only linear feedback. The participants were blinded as to what algorithm they were using. They then answered survey questions about their opinions of the models. RESULTS: The surgeons overwhelmingly preferred the constraint-based model. They generally preferred the constraint-based model in the individual questions as well. CONCLUSIONS: Follow-up work can be done to fine-tune the parameters in the model, but this study shows that a sophisticated algorithm can make a significant difference even on a low-fidelity haptic device.

Performance Assessment for Mastoidectomy.

Objective The aim of this report is to provide a review of the current literature for assessment of performance for mastoidectomy, to identify the current assessment tools available in the literature, and to summarize the evidence for their validity. Data Sources The MEDLINE database was accessed via PubMed. Review Methods Inclusion criteria consisted of English-language published articles that reported use of a mastoidectomy performance assessment tool. Studies ranged from 2007 to November 2015 and were divided into 2 groups: intraoperative assessments and those performed with simulation (cadaveric laboratory or virtual reality). Studies that contained specific reliability analyses were also highlighted. For each publication, validity evidence data were analyzed and interpreted according to conceptual definitions provided in a recent systematic review on the modern framework of validity evidence. Conclusions Twenty-three studies were identified that met our inclusion criteria for review, including 4 intraoperative objective assessment studies, 5 cadaveric studies, 10 virtual reality simulation studies, and 4 that used both cadaveric assessment and virtual reality. Implications for Practice A review of the literature revealed a wide variety of mastoidectomy assessment tools and varying levels of reliability and validity evidence. The assessment tool developed at Johns Hopkins possesses the most validity evidence of those reviewed. However, a number of agreed-on specific metrics could be integrated into a standardized assessment instrument to be used nationally. A universally agreed-on assessment tool will provide a means for developing standardized benchmarks for performing mastoid surgery.

Integration of high-resolution data for temporal bone surgical simulations.

PURPOSE: To report on the state of the art in obtaining high-resolution 3D data of the microanatomy of the temporal bone and to process that data for integration into a surgical simulator. Specifically, we report on our experience in this area and discuss the issues involved to further the field. DATA SOURCES: Current temporal bone image acquisition and image processing established in the literature as well as in house methodological development. REVIEW METHODS: We reviewed the current English literature for the techniques used in computer-based temporal bone simulation systems to obtain and process anatomical data for use within the simulation. Search terms included "temporal bone simulation, surgical simulation, temporal bone." Articles were chosen and reviewed that directly addressed data acquisition and processing/segmentation and enhancement with emphasis given to computer-based systems. We present the results from this review in relationship to our approach. CONCLUSIONS: High-resolution CT imaging ([Formula: see text] voxel resolution), along with unique image processing and rendering algorithms, and structure-specific enhancement are needed for high-level training and assessment using temporal bone surgical simulators. Higher-resolution clinical scanning and automated processes that run in efficient time frames are needed before these systems can routinely support pre-surgical planning. Additionally, protocols such as that provided in this manuscript need to be disseminated to increase the number and variety of virtual temporal bones available for training and performance assessment.

Translating the simulation of procedural drilling techniques for interactive neurosurgical training.

BACKGROUND: Through previous efforts we have developed a fully virtual environment to provide procedural training of otologic surgical technique. The virtual environment is based on high-resolution volumetric data of the regional anatomy. These volumetric data help drive an interactive multisensory, ie, visual (stereo), aural (stereo), and tactile, simulation environment. Subsequently, we have extended our efforts to support the training of neurosurgical procedural technique as part of the Congress of Neurological Surgeons simulation initiative. OBJECTIVE: To deliberately study the integration of simulation technologies into the neurosurgical curriculum and to determine their efficacy in teaching minimally invasive cranial and skull base approaches. METHODS: We discuss issues of biofidelity and our methods to provide objective, quantitative and automated assessment for the residents. RESULTS: We conclude with a discussion of our experiences by reporting preliminary formative pilot studies and proposed approaches to take the simulation to the next level through additional validation studies. CONCLUSION: We have presented our efforts to translate an otologic simulation environment for use in the neurosurgical curriculum. We have demonstrated the initial proof of principles and define the steps to integrate and validate the system as an adjuvant to the neurosurgical curriculum.

Virtual mastoidectomy performance evaluation through multi-volume analysis.

PURPOSE: Development of a visualization system that provides surgical instructors with a method to compare the results of many virtual surgeries (n > 100). METHODS: A masked distance field models the overlap between expert and resident results. Multiple volume displays are used side-by-side with a 2D point display. RESULTS: Performance characteristics were examined by comparing the results of specific residents with those of experts and the entire class. CONCLUSIONS: The software provides a promising approach for comparing performance between large groups of residents learning mastoidectomy techniques.

Virtual temporal bone dissection system: OSU virtual temporal bone system: development and testing.

OBJECTIVES/HYPOTHESIS: The objective of this project was to develop a virtual temporal bone dissection system that would provide an enhanced educational experience for the training of otologic surgeons. STUDY DESIGN: A randomized, controlled, multi-institutional, single-blinded validation study. METHODS: The project encompassed four areas of emphasis: structural data acquisition, integration of the system, dissemination of the system, and validation. RESULTS: Structural acquisition was performed on multiple imaging platforms. Integration achieved a cost-effective system. Dissemination was achieved on different levels including casual interest, downloading of software, and full involvement in development and validation studies. A validation study was performed at eight different training institutions across the country using a two-arm randomized trial where study subjects were randomized to a 2-week practice session using either the virtual temporal bone or standard cadaveric temporal bones. Eighty subjects were enrolled and randomized to one of the two treatment arms; 65 completed the study. There was no difference between the two groups using a blinded rating tool to assess performance after training. CONCLUSIONS: A virtual temporal bone dissection system has been developed and compared to cadaveric temporal bones for practice using a multicenter trial. There was no statistical difference between practice on the current simulator compared to practice on human cadaveric temporal bones. Further refinements in structural acquisition and interface design have been identified, which can be implemented prior to full incorporation into training programs and used for objective skills assessment.

Virtual simulation of mouse anatomy and procedural techniques.

Translational science requires the use of mouse models for the characterization of disease and evaluation of treatment therapies. However, often there is a lack of comprehensive training for scientists in the systemic and regional anatomy of the mouse that limits their ability to perform studies involving complex interventional procedures. We present our methodologies for the development, evaluation, and dissemination of an interactive 3D mouse atlas that includes designs for presenting emulation of procedural technique. We present the novel integration of super-resolution imaging techniques, depth-of-field interactive volume rendering of large data, and the seamless delivery of remote visualization and interaction to thin clients.

Translating surgical metrics into automated assessments.

In the effort to promote more continuous and quantitative assessment of surgical proficiency, there is an increased need to define and establish common surgical metrics. Furthermore, as various pressures such as limited duty hours and access to educational resources, including materials and expertise, place increased demands on training, the value of quantitative automated assessment becomes increasingly apparent. We present our methods to establish common surgical metrics within the otology and neurotology community and our initial efforts in the subsequent transfer of these metrics into objective automated assessments provided via a simulation environment.

Automatic scoring of virtual mastoidectomies using expert examples.

PURPOSE: Automatic scoring of resident performance on a virtual mastoidectomy simulation system is needed to achieve consistent and efficient evaluations. By not requiring immediate expert intervention, the system provides a completely objective assessment of performance as well as a self-driven user assessment mechanism. METHODS: An iconic temporal bone with surgically important regions defined into a fully partitioned segmented dataset was created. Comparisons between expert-drilled bones and student-drilled bones were computed based on gradations with both Euclidean and Earth Mover's Distance. Using the features derived from these comparisons, a decision tree was constructed. This decision tree was used to determine scores of resident surgical performance. The algorithm was applied on multiple expert comparison bones and the scores averaged to provide reliability metric. RESULTS: The reliability metrics for the multi-grade scoring system are better in some cases than previously reported binary classification metrics. The two scoring methods given provide a trade-off between accuracy and speed. CONCLUSIONS: Comparison of virtually drilled bones with expert examples on a voxel level provides sufficient information to score them and provide several specific quality metrics. By merging scores from different expert examples, two related metrics were developed; one is slightly faster and less accurate, while a second is more accurate but takes more processing time.