Exhausting power from the hot fusion core to the plasma-facing components is one fusion energy’s biggest challenges. The MAST Upgrade tokamak uniquely integrates strong containment of neutrals within the exhaust area (divertor) with extreme divertor shaping capability. By systematically altering the divertor shape, this study shows the strongest evidence to date to our knowledge that long-legged divertors with a high magnetic field gradient (total flux expansion) deliver key power exhaust benefits without adversely impacting the hot fusion core. These benefits are already achieved with relatively modest geometry adjustments that are more feasible to integrate in reactor designs. Benefits include reduced target heat loads and improved access to, and stability of, a neutral gas buffer that ‘shields’ the target and enhances power exhaust (detachment). Analysis and model comparisons shows these benefits are obtained by combining multiple shaping aspects: long-legged divertors have expanded plasma-neutral interaction volume that drive reductions in particle and power loads, while total flux expansion enhances detachment access and stability. Containing the neutrals in the exhaust area with physical structures further augments these shaping benefits. These results demonstrate strategic variation in the divertor geometry and magnetic topology is a potential solution to one of fusion’s power exhaust challenge. (Figure presented.)

Objectives: To compare medical students' and residents' knowledge retention of assessment, diagnosis and treatment procedures, as well as a learning experience, of patients with spinal trauma after training with either a Virtual Patient case or a video-recorded traditional lecture. Methods: A total of 170 volunteers (85 medical students and 85 residents in orthopedic surgery) were randomly allocated (stratified for student/resident and gender) to either a video-recorded standard lecture or a Virtual Patient-based training session where they interactively assessed a clinical case portraying a motorcycle accident. The knowledge retention was assessed by a test immediately following the educational intervention and repeated after a minimum of 2 months. Participants' learning experiences were evaluated with exit questionnaires. A repeated-measures analysis of variance was applied on knowledge scores. A total of 81% (n = 138) of the participants completed both tests. Results: There was a small but significant decline in first and second test results for both groups (F-(1,F-135) = 18.154, p = 0.00). However, no significant differences in short-term and long-term knowledge retention were observed between the two teaching methods. The Virtual Patient group reported higher learning experience levels in engagement, stimulation, general perception, and expectations. Conclusions: Participants' levels engagement were reported in favor of the VP format. Similar knowledge retention was achieved through either a Virtual Patient or a recorded lecture.

The influence of the faix and tentorium on brain injury biomechanics during impact was studied with finite element (FE) analysis. Three detailed 3D FE head models were created based on the images of a healthy, normal size head. Two of the models contained the addition of falx and tentorium with material properties from previously published experiments. Impact loadings from a reconstructed concussive case in a sport accident were applied to the two players involved. The results suggested that the faix and tentorium could induce large strains to the surrounding brain tissues, especially to the corpus callosum and brainstem. The tentorium seemed to constrain the motion of the cerebellum while inducing large strain in the brainstem in both players involved in the accident (one player had mainly coronal head rotation and the other had both coronal and transversal rotations). Since changed strain levels were observed in the brainstem and corpus callosum, which are classical sites for diffuse axonal injuries (DAI), we confirmed the importance of using accurate material properties for falx and tentorium in a FE head model when studying traumatic brain injuries. 

This RCT study aimed to investigate if VIS-Ed (Visualization through Imaging and Simulation - Education) had the potential to improve medical student education and specialist training in clinical diagnosis and treatment of trauma patients. The participants' general opinion was reported as high in both groups (lecture vs. virtual patient (VP)). Face validity of the VIS-Ed for cervical spine trauma was demonstrated and the VP group reported higher stimulation and engagement compared to the lecture group. No significant difference in the knowledge test between both groups could be observed, confirming our null hypothesis that VIS-Ed was on par with a lecture.

Brain edema is one of the most common consequences of serious head injury because of the enhancement of water content and thus the increased brain volume. Once the brain compensation mechanisms have been exhausted, the intracranial pressure (ICP) will increase exponentially because the brain is enclosed in the rigid skull. Previous research suggests that the poroelastic theory provides a solution for studying the fluid flow in the brain. In this paper, poroelastic theory is used to study the intracranial pressure distribution due to traumatic brain edema by a detailed 3D finite element brain model.

Brain edema is one of the most common consequences of serious traumatic brain injuries which is usually accompanied with increased Intracranial Pressure (ICP) due to water content increment. A three dimensional finite element model of brain edema is used to study intracranial pressure in this paper. Three different boundary conditions at the end of Cerebral Spinal Fluid (CSF) were used to investigate the boundary condition effects on the volume-pressure curve based on the current model. Compared with the infusion experiments, results from the simulations show that exponential pressure boundary condition model corresponds well with the experiment

A method to automatically generate finite element (FE) head models is presented in this paper. Individual variation in geometry of the head should be taken into consideration in future injury-prediction research. To avoid inter- and intra-operator variation due to manual segmentation, a robust and accurate algorithm is suggested. The current approach utilises expectation maximisation classification and skull stripping. The whole process from geometry extraction to model generation is converted into an automatic scheme. The models that are generated from the proposed method are validated in terms of segmentation accuracy, element quality and injury-prediction ability. The segmentations of the white matter and grey matter are about 90% accurate and the models have good element quality, with 94% of the elements having a Jacobian above 0.5. Using the experimental data from post-mortem human subject heads, nodal displacements were compared with the data collected from the simulations with the FE head models. The results are promising, indicating that the proposed method is good enough to generate patient-specific model for brain injury prediction. Further improvement can be made in terms of geometry accuracy and element quality.

The influence of sulci in dynamic finite element simulations of the human head has been investigated. First, a detailed 3D FE model was constructed based on an MRI scan of a human head. A second model with a smoothed brain surface was created based on the same MRI scan as the first FE model. These models were validated against experimental data to confirm their human-like dynamic responses during impact. The validated FE models were subjected to several acceleration impulses and the maximum principle strain and strain rate in the brain were analyzed. The results suggested that the inclusion of sulci should be considered for future FE head models as it alters the strain and strain distribution in an FE model.

A non-invasive method for measuring intracranial pressure (ICP) is provided. A numerical model such as finite element model is developed in order to calculate the ICP, strain or stress for patients who suffers from hematoma, edema or tumor. The method can further provide local maximum principle strain that can provide information about possible subsequent brain injury, such as diffuse axonal injury, in sensitive region of the brain. Based on computer tomography or magnetic resonance images an individual diagnosis and treatment plan can be formed for each patient.

(FR)L'invention concerne un procédé non invasif visant à mesurer la pression intracrânienne (ICP). Un modèle numérique tel qu’un modèle par éléments finis est développé afin de calculer l’ICP, la déformation ou la contrainte pour des patients souffrant d’un hématome, d’un œdème ou d’une tumeur. Le procédé peut en outre fournir le maximum local de déformation principale qui peut donner des informations concernant d’éventuelles lésions cérébrales subséquentes, comme des lésions axonales diffuses, dans une région sensible du cerveau. Sur la base d’une tomographie informatisée ou d’images par résonance magnétique, un diagnostic et un plan de traitement individualisés peuvent être formulés pour chaque patient.