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Objective Realistic, safe, and efficient modalities for simulation-based training are highly warranted to enhance the quality of surgical education, and they should be incorporated in resident training. The aim of this study was to develop a patient-specific virtual cerebral aneurysm-clipping simulator with haptic force feedback and real-time deformation of the aneurysm and vessels. Methods A prototype simulator was developed from 2012 to 2016. Evaluation of virtual clipping by blood flow simulation was integrated in this software, and the prototype was evaluated by 18 neurosurgeons. In 4 patients with different medial cerebral artery aneurysms, virtual clipping was performed after real-life surgery, and surgical results were compared regarding clip application, surgical trajectory, and blood flow. Results After head positioning and craniotomy, bimanual virtual aneurysm clipping with an original forceps was performed. Blood flow simulation demonstrated residual aneurysm filling or branch stenosis. The simulator improved anatomic understanding for 89% of neurosurgeons. Simulation of head positioning and craniotomy was considered realistic by 89% and 94% of users, respectively. Most participants agreed that this simulator should be integrated into neurosurgical education (94%). Our illustrative cases demonstrated that virtual aneurysm surgery was possible using the same trajectory as in real-life cases. Both virtual clipping and blood flow simulation were realistic in broad-based but not calcified aneurysms. Virtual clipping of a calcified aneurysm could be performed using the same surgical trajectory, but not the same clip type. Conclusions We have successfully developed a virtual aneurysm-clipping simulator. Next, we will prospectively evaluate this device for surgical procedure planning and education.

This study investigated the effect of a 12-week recreational skiing intervention on lower limb muscle strength and cardiorespiratory fitness in participants with unilateral total knee arthroplasty (TKA). Twenty-seven older adults (70 ± 5 years) were assigned to the intervention (n = 13) or control group (n = 14) after surgery (2.5 ± 1 years). Leg muscle strength was measured using an IsoMed 2000 dynamometer and cardiorespiratory fitness was determined by cycle ergometry before and after the intervention as well as after an 8-week retention period. The skiing intervention led to increased muscle strength in the operated leg during unilateral single joint isometric extension (maximal force: 11%; P

Burn depth and burn size are crucial determinants for assessing patients suffering from burns. Therefore, a correct evaluation of these factors is optimal for adapting the appropriate treatment in modern burn care. Burn surface assessment is subject to considerable differences among clinicians. This work investigated the accuracy among experts based on conventional surface estimation methods (e.g. "Rule of Palm", "Rule of Nines" or "Lund-Browder Chart"). The estimation results were compared to a computer-based evaluation method. Survey data was collected during one national and one international burn conference. The poll confirmed deviations of burn depth/size estimates of up to 62% in relation to the mean value of all participants. In comparison to the computer-based method, overestimation of up to 161% was found. We suggest introducing improved methods for burn depth/size assessment in clinical routine in order to efficiently allocate and distribute the available resources for practicing burn care.

Hintergrund: Isokinetische Gerate nehmen im Bereich der Kraftdiagnostik einen hohen Stellenwert ein. Das breite Angebot entsprechender Produkte am Markt wurde in den letzten Jahren um das IsoMed 2000 erweitert. Bevor ein Gerat in der Diagnostik Verwendung finden kann, mussen Informationen uber die Reliabilitat fur spezifische Anwendungen vorliegen. Wahrend es fur das IsoMed 2000 diesbez. bereits einzelne Studien hinsichtlich der Maximalkraft gibt, fehlen diese bislang ganzlich fur den Bereich der Kraftausdauer. Das Ziel dieser Studie bestand darin, die Reliabilitat mehrerer Methoden der Quantifizierung der Kraftausdauer am IsoMed 2000 zu untersuchen. Methode: Eine Stichprobe von 33 sportlich aktiven gesunden Probanden (Alter: 23,8 ± 2,6 J.) partizipierte an einem Gewohnungs- und zwei Testterminen, mit 3–4 Tagen Abstand zwischen den Terminen. Der Test umfasste eine Serie von 30 maximal durchgefuhrten konzentrischen Beuge- und Streckbewegungen des rechten Knies bei einer Winkelgeschwindigkeit von 180 °/s. Ausgehend von den Parametern maximales Drehmoment und Arbeit fur jede Einzelwiederholung wurden Indizes der absoluten (KADabs) und relativen (KADrel) Kraftausdauer abgeleitet. Die KADabs wurde anhand des Mittelwerts uber alle Testwiederholungen, die KADrel auf zwei Arten berechnet: zum einen als prozentueller Abfall zwischen den ersten und letzten 5 Wiederholungen (KADrelA), zum anderen als negative Steigung der linearen Regressionsgleichung uber alle Wiederholungen (KADrelB). Systematische Fehler wurden anhand gepaarter t-Tests gepruft, die relative und absolute Reliabilitat anhand des Intraklassenkorrelationskoeffizienten (ICC 2.1) bzw. des Standardmessfehlers (SEM%). Ergebnisse / Schlussfolgerung: Zusammenfassend wurden fur die Extension sowohl hinsichtlich der Messung der KADabs als auch – in etwas abgeschwachter Form – fur die KADrel durchweg hohe ICCWerte von 0,76–0,89 verbunden mit akzeptablen SEM%-Werten von 1,2–5,9 % gefunden. Fur die Flexion gilt dies lediglich fur die KADabs, wahrend die Ergebnisse fur die KADrel mit ICC- und SEM%-Werten von 0,42–0,62 bzw. 9,6–17,7 % deutlich schlechter ausfielen und Zweifel an der klinischen Verwertbarkeit aufwerfen. Sollte die KADrel fur die Flexion dennoch erhoben werden, so empfiehlt es sich – angesichts der jeweils etwas hoheren Reliabilitat – (i) die KADrelB und (ii) den Parameter Arbeit heranzuziehen sowie – angesichts der festgestellten betrachtlichen Lernund Gewohnungseffekte von ≈10 % – (iii) eine Gewohnungsphase durchzufuhren, die uber den in dieser Studie praktizierten Gewohnungstermin hinausgeht.

The present study was conducted to evaluate the relative and absolute reproducibility of the IsoMed 2000-dynamometer in measuring Peak Torque (PT) during maximum isometric and isokinetic (60 and 120°/s) knee flexion and extension. Thirty four physically active male subjects (mean age: 23.2 years) were measured in three sessions (T1―T3), 48-72 h apart. Repeated measures analysis of variance (ANOVA) with Bonferroni post hoc adjustments revealed significant systematic errors for isokinetic flexion measurements with mean values on the second and third visit being around 3-5% higher than the corresponding values obtained in the first visit. Intraclass correlation coefficients (ICC 2,1) of 0.90-0.98 and 0.94-0.98 combined with values of standard error of measurement (SEM) of 5.5―9.1 and 4.0-9.0 Nm were found for T1―T2 and T2-T3, respectively. Based on the systematic errors found for flexor measurements and a clear improvement in reproducibility parameters from T1―T2 to T2―T3 for nearly all measurements, we recommend the use of a familiarisation session prior to actual testing.

Systematic assessment of muscle strength of the lower extremities throughout the annual training cycle in athletes is crucial from a performance perspective for the optimization of the training process, as well as a health perspective with regard to injury prevention. The main aim of the present study was to determine isokinetic muscle strength of the knee flexors and extensors in female handball players at the beginning of a preparatory period and to assess whether there were any differences between players of different performance levels. The performance level was expressed by means of membership of the Women’s Junior National Handball Team (JNT, n=8) or the Women’s National Handball Team (NT, n=9). The isokinetic peak torque during concentric and eccentric single-joint knee flexion and extension was measured at angular velocities of 60, 180, 240°/s (concentric) and 60°/s (eccentric). The Mann- Whitney test showed no significant differences in the peak torques or ipsilateral ratios between the two groups. The bilateral force deficit (BFD) for concentric extension at 240°/s was significantly higher in the JNT compared with the NT (p=0.04; d=1.02). However, the results of individual evaluation show that the BFD was more frequent in the NT in most measurements. A high BFD was evident in the eccentric mode in both groups highlighting a need for particular strengthening. With regard to low strength ratios a prevention programme should be suggested for both observed groups of professional female handball players to reduce the risk of injury.

Providing suitable training for aspiring neurosurgeons is becoming more and more problematic. The increasing popularity of the endovascular treatment of intracranial aneurysms leads to a lack of simple surgical situations for clipping operations, leaving mainly the complex cases, which present even experienced surgeons with a challenge. To alleviate this situation, we have developed a training simulator with haptic interaction allowing trainees to practice virtual clipping surgeries on real patient-specific vessel geometries. By using specialized finite element (FEM) algorithms (fast finite element method, matrix condensation) combined with GPU acceleration, we can achieve the necessary frame rate for smooth real-time interaction with the detailed models needed for a realistic simulation of the vessel wall deformation caused by the clamping with surgical clips. Vessel wall geometries for typical training scenarios were obtained from 3D-reconstructed medical image data, while for the instruments (clipping forceps, various types of clips, suction tubes) we use models provided by manufacturer Aesculap AG. Collisions between vessel and instruments have to be continuously detected and transformed into corresponding boundary conditions and feedback forces, calculated using a contact plane method. After a training, the achieved result can be assessed based on various criteria, including a simulation of the residual blood flow into the aneurysm. Rigid models of the surgical access and surrounding brain tissue, plus coupling a real forceps to the haptic input device further increase the realism of the simulation.

Wound management, which is based on wound diagnostic, will become more and more important and will develop even more towards evidence-based medicine. Evidence-based medicine is the current state of the art in clinical research. The data quality is very much dependent on the transparency of the treatment and its objective evaluation. An objectification requires comparable patients with comparable wounds as well as comparable documentation and quality of the documentation.