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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.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.Ipsilesional corticomotor excitability increased by 25% after game-based movement priming (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.

A atividade garimpeira e tradicional na regiao centro-sul do estado do Mato Grosso desde o seculo XVIII, onde inicialmente as lavras de ouro se davam nos aluvioes e atualmente se concentram em filoes com ouro livre. Entretanto, recentes verificacoes mostraram a presenca de mineralizacoes disseminadas, uma forma incomum de ocorrencia na regiao, em dois depositos – Adao Rodui e Jonas Gimenez – localizados no municipio de Pocone e no distrito de Cangas, respectivamente. O minerio principal e constituido por ouro, em teores significativos, associado a pirita e magnetita subordinadamente. O presente trabalho apresenta a caracterizacao do minerio aurifero contido nestes depositos, em concentracoes que chegam a ate 25,15 ppm em rocha total e a 560,25 ppm em concentrados de sulfetos. O minerio e hospedado em rochas do Grupo Cuiaba (Faixa Paraguai), de idade neoproterozoica, relacionadas a Orogenia Brasiliana-Pan Africana. As rochas foram metamorfizadas em facies xisto verde, com evidencias de intensa alteracao hidrotermal do tipo disseminada, em veio e stockwork, formadores de quartzo, magnetita, pirita e ouro. As rochas hospedeiras sao descritas como pacotes espessos de filito e metarritmito, cujo acamamento sedimentar (S0) e sobreposto por tres fases deformacionais progressivas (D1, D2 e D3), que aparentemente controlaram a entrada dos fluidos hidrotermais mineralizantes. A fase D1 e geradora de foliacao S1 paralela ao acamamento sedimentar, dobras F1 recumbentes e uma familia de veios de quartzo V1 de direcao NE. A segunda fase deformacional D2 esta relacionada a uma foliacao penetrativa de alto ângulo S2, plano axial as dobras abertas a suaves, assimetricas e reclinadas F2 e uma familia de veios de quartzo V2 foliados e de direcao NE. A fase D3 tem caracteristicas predominantemente rupteis e e representada por familias de foliacoes de direcao NW S3, por vezes preenchidas por quartzo formando os veios V3, nao foliados. A ocorrencia de ouro associado a assembleias hidrotermais disseminadas ou em veios, com forte controle estrutural e litologico, relacionadas a estruturas deformacionais ducteis-rupteis em rochas metamorficas de baixo grau sugerem que as mineralizacoes estudadas sao do tipo ouro orogenico, apresentando similaridades com o deposito de Paracatu, em Minas Gerais, incluindo rochas hospedeiras, alteracao hidrotermal, minerais de minerio, ambiente tectonico e idade.

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

PurposeVeress 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.MethodsWe 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$$^{\text {TM}}$$TM(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.ResultsA 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.ConclusionThe 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.

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.

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.

Virtual reality (VR) surgical training and presurgical planning require the creation of 3D virtual models of patient anatomy from medical scan data. Real-time head tracking in VR applications allows users to navigate in the virtual anatomy from any 3D position and orientation. The process of interactively rendering highly-detailed 3D volumetric data of anatomical models from a dynamically changing observer's perspective is extremely demanding for computational resources. Parallel computing presents a solution to this problem, involving a distributed volume graphics rendering system composed of multiple nodes concurrently working on different portions of the output streaming, which are later integrated to form the final view. This paper presents a distributed graphics rendering system consisting of multiple GPU-based heterogeneous nodes running a best-effort rendering scheme. Experiments show promising results in terms of efficiency and performance for rendering medical volumes in real time.

Haptics relates to the science of enabling “touch” of simulated objects in a virtual and controlled environment. It is an interdisciplinary field including computer science, engineering, physics, and human perception. Haptics is divided in three disciplines: human, machine, and computer haptics. Each haptic device is composed of electromechanical sensors and actuators that enable tactile feedback by interacting with virtual objects. Current examples of haptic devices include exoskeletal and stand-alone devices that are used on different medical training simulators.

This study explores the usefulness of virtual simulation training for learning to place pedicle screws in the lumbar spine.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.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%).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.

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.

Manual skill is important for surgeons, but current methods to evaluate sensory-motor skills in applicants to a surgical residency are limited.To develop a method of testing sensory-motor skill using objective and reproducible virtual reality simulation.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.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).Our study represents a first step in the direction of an objective, standard, computer-scored test of motor and haptic ability.

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.

Background In this study, we evaluated the use of a part-task simulator with 3-dimensional and haptic feedback as a training tool for percutaneous spinal needle placement. Objective To evaluate the learning effectiveness in terms of entry point/target point accuracy of percutaneous spinal needle placement on a high-performance augmented-reality and haptic technology workstation with the ability to control the duration of computer-simulated fluoroscopic exposure, thereby simulating an actual situation. Methods Sixty-three fellows and residents performed needle placement on the simulator. A virtual needle was percutaneously inserted into a virtual patient's thoracic spine derived from an actual patient computed tomography data set. Results Ten of 126 needle placement attempts by 63 participants ended in failure for a failure rate of 7.93%. From all 126 needle insertions, the average error (15.69 vs 13.91), average fluoroscopy exposure (4.6 vs 3.92), and average individual performance score (32.39 vs 30.71) improved from the first to the second attempt. Performance accuracy yielded P = .04 from a 2-sample t test in which the rejected null hypothesis assumes no improvement in performance accuracy from the first to second attempt in the test session. Conclusion The experiments showed evidence (P = .04) of performance accuracy improvement from the first to the second percutaneous needle placement attempt. This result, combined with previous learning retention and/or face validity results of using the simulator for open thoracic pedicle screw placement and ventriculostomy catheter placement, supports the efficacy of augmented reality and haptics simulation as a learning tool.

Recent studies have shown that mental script-based rehearsal and simulation-based training improve the transfer of surgical skills in various medical disciplines. Despite significant advances in technology and intraoperative techniques over the last several decades, surgical skills training on neurosurgical operations still carries significant risk of serious morbidity or mortality. Potentially avoidable technical errors are well recognized as contributing to poor surgical outcome. Surgical education is undergoing overwhelming change, as a result of the reduction of work hours and current trends focusing on patient safety and linking reimbursement with clinical outcomes. Thus, there is a need for adjunctive means for neurosurgical training, which is a recent advancement in simulation technology. ImmersiveTouch is an augmented reality system that integrates a haptic device and a high-resolution stereoscopic display. This simulation platform uses multiple sensory modalities, re-creating many of the environmental cues experienced during an actual procedure. Modules available include ventriculostomy, bone drilling, percutaneous trigeminal rhizotomy, and simulated spinal modules such as pedicle screw placement, vertebroplasty, and lumbar puncture. We present our experience with the development of such augmented reality neurosurgical modules and the feedback from neurosurgical residents.

123 p. il. En la Argentina, la inflación es uno de los principales problemas de la economía. El presente proyecto aplica el proceso de minería de datos para encontrar patrones en variables económicas que permitan pronosticar la inflación. Para ello fue necesario obtener datos de economía, comprenderlos, prepararlos, elaborar el modelo de datos y analizar los resultados obtenidos. Con el objetivo de construir el modelo de datos se utilizaron redes neuronales y series de tiempo, de esta manera es posible realizar proyecciones de la inflación. Como resultado del proyecto se encuentran relaciones no lineales entre variables monetarias del sistema financiero asociadas al índice de precios al consumidor.

Aplicaciones de tiempo real como realidad virtual generan un flujo multimedia de tipo de máquina-humano que puede ser dividido tanto espacial como temporalmente para distribuir recursos de procesamiento, memoria o red. Este trabajo describe un protocolo para control de flujo de datos multimedia, donde su generación debe ser distribuida para incrementar el rendimiento. Este protocolo no describe la comunicación del flujo multimedia, sino solamente la comunicación de control para la generación de un único flujo multimedia entre múltiples nodos teniendo en cuenta un esquema de mejor esfuerzo. Para lograr estos objetivos se propone un protocolo de capa de aplicación, el cual utiliza UDP o UDP-lite en capa de transporte, IPv6 multicast en capa de red y Gigabit Ethernet con control de flujo en capa de enlace de datos.

This poster presents a part-task haptic simulator for ophthalmic surgical training developed for the MicrovisTouch simulation platform. This ophthalmic surgical simulator provides both realistic 3D visualization and haptic feedback. Trainees are able to learn interacting with a physics-based dynamic virtual eye model and receiving tactile feedback by handling virtual instruments while simulating a series of surgical tasks and exercises, including micro-dexterity and corneal incision. A pilot study was conducted on the micro-dexterity to measure its effectiveness to evaluate trainees' skills performing precise instrument motion required for ophthalmic surgical procedures.

Background We evaluated the use of a part-task simulator with 3D and haptic feedback as a training tool for a common neurosurgical procedure--placement of thoracic pedicle screws. Objective To evaluate the learning retention of thoracic pedicle screw placement on a high-performance augmented reality and haptic technology workstation. Methods Fifty-one fellows and residents performed thoracic pedicle screw placement on the simulator. The virtual screws were drilled into a virtual patient's thoracic spine derived from a computed tomography data set of a real patient. Results With a 12.5% failure rate, a 2-proportion z test yielded P = .08. For performance accuracy, an aggregate Euclidean distance deviation from entry landmark on the pedicle and a similar deviation from the target landmark in the vertebral body yielded P = .04 from a 2-sample t test in which the rejected null hypothesis assumes no improvement in performance accuracy from the practice to the test sessions, and the alternative hypothesis assumes an improvement. Conclusion The performance accuracy on the simulator was comparable to the accuracy reported in literature on recent retrospective evaluation of such placements. The failure rates indicated a minor drop from practice to test sessions, and also indicated a trend (P = .08) toward learning retention resulting in improvement from practice to test sessions. The performance accuracy showed a 15% mean score improvement and more than a 50% reduction in standard deviation from practice to test. It showed evidence (P = .04) of performance accuracy improvement from practice to test session.

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.

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.

To determine if a computer-based simulation with haptic technology can help surgical trainees improve tactile discrimination using surgical instruments.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.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).Virtual computer-based simulators with integrated haptic technology may improve tactile discrimination required for microsurgical technique.

Visualization methods of medical imagery based on volumetric data constitute a fundamental tool for medical diagnosis, training and pre-surgical planning. Often, large volume sizes and/or the complexity of the required computations present serious obstacles for reaching higher levels of realism and real-time performance. Performance and efficiency are two critical aspects in traditional algorithms based on complex lighting models. To overcome these problems, a volume rendering algorithm, PD-Render intra for individual networked nodes in a parallel distributed architecture with a single GPU per node is presented in this paper. The implemented algorithm is able to achieve photorealistic rendering as well as a high signal-tonoise ratio at interactive frame rates. Experiments show excellent results in terms of efficiency and performance for rendering medical volumes in real time. Fil: Perez Monte, Cristian Federico. Universidad Tecnológica Nacional. Facultad Regional Mendoza. Departamento de Electrónica. Grupo de Investigación Gridtics; Argentina. Universidad Tecnológica Nacional. Facultad Regional Mendoza. Departamento de Sistemas de Información. Laboratorio de Investigación en Cómputo Paralelo/Distribuido; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Informática. Laboratorio Investigación y Desarrollo en Inteligencia Computacional; Argentina Fil: Picolli, Fabiana. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Informática. Laboratorio Investigación y Desarrollo en Inteligencia Computacional; Argentina Fil: Luciano, Cristian. University of Illinois at Chicago. Department of Mechanical and Industrial Engineering; Estados Unidos Fil: Rizzi, Silvio. University of Illinois at Chicago. Department of Mechanical and Industrial Engineering; Estados Unidos Fil: Bianchini, German. Universidad Tecnológica Nacional. Facultad Regional Mendoza. Departamento de Sistemas de Información. Laboratorio de Investigación en Cómputo Paralelo/Distribuido; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza; Argentina Fil: Caymes Scutari, Paola Guadalupe. Universidad Tecnológica Nacional. Facultad Regional Mendoza. Departamento de Sistemas de Información. Laboratorio de Investigación en Cómputo Paralelo/Distribuido; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza; Argentina

This work was carried out as part of the BID-CONICET Project No. 83 “Modeling, Simulation and Control of Flexible Manufacturing Cell. FMC”. It deals with the design and construction of the control system for a Tutorial Flexible Manufacturing Cell (TFMC). The control system modelling was built on a Data Flow Diagram basis. The implementation itself was carried out with Artificial Intelligence techniques and the computer language used was Prolog. The hardware consisted basically of PCs and peripheral devices. The control system has been made and tested and is operating at present at the CUDAR.

This paper presents some simulation results of a tutorial Flexible Manufacturing Cell (FMC). After a hundred of simulation trials, two study cases were chosen, a FMC with a slow and a faster robot. Simulation analysis allowed FMC engineers to draw a balanced design for the new tutorial robot RSA-2.

Volumetric datasets have become essential in virtual reality and haptics simulation for medical and surgical training. Technologies such as computed tomography (CT) and magnetic resonance imaging provide 3D scans of patient anatomy, from which 3D models can be generated to represent highly detailed and complex anatomical structures such as bone, organs, or muscle. Traditionally, 3D models have been represented as polygonal meshes, i.e., surfaces in 3D space consisting of multiple triangles. From the volumetric data, polygonal meshes are constructed using an isosurface extraction algorithm such as Marching Cubes [1]. Furthermore, mesh processing may be required in order to reduce the number of triangles in each model (decimation) and to obtain smooth surfaces. All these preprocessing stages often demand a fair amount of time to generate high quality models. Although methods to automate the segmentation and isosurface creation processes have been discussed in the literature [2], they still require considerable human intervention. Alternatively, anatomical 3D models can be displayed using direct volume rendering, which requires less human participation and minimum data preprocessing, generally at the expense of lower graphics frame rates. Combinations of scene graph managers [3,4] and haptics libraries [5] have been used in surgical simulations for graphics and haptics rendering of 3D models [6,7]. The goals of these simulations are simultaneous visualization of complex 3D models and tactile interaction with anatomy at interactive frame rates. While frame rates in the order of 30–60 Hz are acceptable for graphics rendering, the minimum required rate of 1 kHz for haptics rendering makes it a nontrivial problem when dealing with complex and highly detailed polygonal models. On the other hand, volume-based haptics techniques have proven themselves capable of generating force feedback from complex anatomies at interactive frame rates [8,9]. This paper presents a comparison of haptics rendering algorithms combined with polygonal graphics rendering within the framework of medical simulation. This evaluation seeks to assess the quality of the haptic feedback provided as well as identifying the best algorithm in terms of rendering time.

This is an excellent overview of the pros and cons of surgical VR techniques. In the Netherlands, it is concluded that training scenarios for complicated endoscopic procedures are lacking. A cultural shift in the teaching hospitals is thus needed both for trainers and trainees.[94] The authors also focus on the fact that so far it has not been proven that a virtual environment can improve neurosurgical training. The question “Why is that so?” is not fully answered! Limited dexterity will result in neurosurgical trainees not developing their skills to an extent that will convert them from novices into experienced surgeons.[89–91] Most importantly, however, all surgeons need to be able to reflect over how they are performing during operative procedures if they are to become true experts.[92] Moving into the topic “endoscopic surgery,” we also change our working space in many ways.[88] Most importantly, we change our normal working 3D space into a 2D space. Thereby we have to learn new ways of obtaining a 3D perception. Most literature on surgical VR techniques is dealing with multi-port endoscopy, where surgeons are working in an artificial, distended operative field. This is in contrast to neurosurgery, where only one endoscopic port is used. Models of removing gall bladders were among the first VR scenarios. While training with VR-simulators, there is a significant difference in the number of mistakes and speed between experienced and novice surgeons.[87] This fact cannot simply be transfered to the learning of endoscopy in neurosurgery. In endoscopic neurosurgery, using a single endoscope to both view and manipulate instruments in narrow spaces under the brain with very limited degrees of finger/hand movements makes a significant difference.[89] In real surgical life, sensing is a key point for neurosurgeons. For spatio/temporal skills, using the sense of touch is an important skill to learn and master. For technical reasons, haptics are most often not included in the VR systems on the market.[95] Verbal teaching of haptics is a challenging task. The range of haptic sensitivity varies from person to person, and possibly also from dominant to non-dominant hand in the same person. Bring a brain retractor into the field and demonstrate to your trainee how gentle your retraction of the brain is. How can the trainee sense what you are doing?[89,93] To the best of my knowledge, the topic of “how to learn to use a brain spatula” has never been introduced in neurosurgical training, not even in the present paper.No one mentions the fact that the trainee learns only how to use a spatula by watching his mentor in no way can the pressure-sensing of the spatula on the brain be transferred from trainer to trainee in the present operating room situations. We have therefore developed a Virtual Brain model using haptic feedback to develop different pressures of the retractor, and thus different deformations of the brain.[93] Now we can teach trainees how the true pressure equals the monitored pressure and the brain shape/deformations are correlated.[86] The neurosurgical VR training is thus different from training in conventional multi-port endoscopy. Neurosurgeons have to use VR systems that develop dexterity and transfer it into an automatic dexterity, whereby haptics are needed in the coming neurosurgical VR models.

(Tesis) Programa de Pedagogía para Licenciados El Colegio en el cual se realizó la práctica es el Arturo Prat, ubicado en la comuna de Talagante. Esta ciudad está distante 35 kilómetros al sur oriente de Santiago y el establecimiento está inmerso en el sector urbano de la comuna, cercano a importantes instituciones como la Comisaría de Carabineros, Centro de Salud Familiar Doctor Alberto Allende Jones, Parroquia Sagrado Corazón y otros establecimientos educacionales, uno de carácter particular subvencionado y tres de carácter municipal. El establecimiento cuenta con una matrícula de 332 alumnos, desde prekinder a cuarto año de enseñanza media. Hay un curso por nivel y se busca que haya matrícula 'reducida', con 30 alumnos máximo por curso para facilitar un buen ambiente de aprendizaje. El funcionamiento del establecimiento se desarrolla en media jornada para la educación preescolar y en jornada completa para la enseñanza básica y media.

Based on a study of 48 neurological residents using a high fidelity haptic/graphic virtual reality simulator to perform ventricular cannulation, we recorded absolute Euclidean distance from the catheter tip to the foramen of Monroe within the ventricle. The data suggest that as expected, successful first attempts to cannulate the virtual 'shifted ventricle' are much less frequent than previous assessments with normal virtual ventricular anatomy. Furthermore, the significant improvement observed by the second attempt implies that the learning curve has been affected and the process 'jump started'.