Search results for "graphics"
showing 10 items of 1223 documents
Mapping of the human visual cortex using image-guided transcranial magnetic stimulation
2002
We describe a protocol using transcranial magnetic stimulation (TMS) to systematically map the visual sensations induced by focal and non-invasive stimulation of the human occipital cortex. TMS is applied with a figure of eight coil to 28 positions arranged in a 2x2-cm grid over the occipital area. A digitizing tablet connected to a PC computer running customized software, and audio and video recording are used for detailed and accurate data collection and analysis of evoked phosphenes. A frameless image-guided neuronavigational device is used to describe the position of the actual sites of the stimulation coils relative to the cortical surface. Our results show that TMS is able to elicit p…
A multiparametric magnetic resonance imaging-based virtual reality surgical navigation tool for robotic-assisted radical prostatectomy
2019
Objective Increased computational power and improved visualization hardware have generated more opportunities for virtual reality (VR) applications in healthcare. In this study, we test the feasibility of a VR-assisted surgical navigation system for robotic-assisted radical prostatectomy. Material and methods The prostate, all magnetic resonance imaging (MRI) visible tumors, and important anatomic structures like the neurovascular bundles, seminal vesicles, bladder, and rectum were contoured on a multiparametric MRI using an in-house segmentation software. Three-dimensional (3-D) VR models were rendered and evaluated in a side room of the operating room. While interacting with the VR platfo…
CT-Angiographie bei arterieller Verschlußkrankheit: Vergleich von 3 Rekonstruktionsverfahren
1997
Purpose To evaluate different rendering techniques of CT data for the assessment of long vessel segments in peripheral vascular occlusive disease. Material and methods 40 CT angiograms (aortoiliac: n = 20, leg arteries: n = 20) were viewed using three different rendering techniques: 1, maximum intensity projection (MIP); 2, volume rendering (VR); 3, shaded surface display (SSD). CT angiograms were obtained in 6 or 8 projections. Axial cross-section images were analysed using an interactive cine mode. Intraarterial DSA was the standard in all cases. Results The sensitivities for the diagnosis of occlusive disease were 100% (cross-section images), 94% (MIP), 91% (VR) and 93% (SSD). The specif…
Comparative ergonomic workflow and user experience analysis of MRI versus fluoroscopy-guided vascular interventions: an iliac angioplasty exemplar ca…
2014
A methodological framework is introduced to assess and compare a conventional fluoroscopy protocol for peripheral angioplasty with a new magnetic resonant imaging (MRI)-guided protocol. Different scenarios were considered during interventions on a perfused arterial phantom with regard to time-based and cognitive task analysis, user experience and ergonomics. Three clinicians with different expertise performed a total of 43 simulated common iliac angioplasties (9 fluoroscopic, 34 MRI-guided) in two blocks of sessions. Six different configurations for MRI guidance were tested in the first block. Four of them were evaluated in the second block and compared to the fluoroscopy protocol. Relevant…
Animación, documental y memoria. La representación animada de la dictadura chilena
2018
Resumen: La animación aparece cada vez más en producciones sobre sucesos relacionados con la memoria. Nuestro objetivo es ana lizar las obras que incorporan escenas animadas para representar la dictadura chilena y profundizar en la convergencia entre animación, documental y memoria. Desde una perspectiva cualitativa, combi namos el análisis de las animaciones con entrevistas a sus directores. Los resultados muestran que la animación es un formato versátil, que permite a los autores superar la ausencia de imágenes de archivo, suavi zar el grado de representación de los suce sos traumáticos, abaratar costes, conectar la memoria con las nuevas generaciones y favorecer la empatía del espectador…
Case-specific performance of MM-PBSA, MM-GBSA, and SIE in virtual screening.
2015
In drug discovery the reliable prediction of binding free energies is of crucial importance. Methods that combine molecular mechanics force fields with continuum solvent models have become popular because of their high accuracy and relatively good computational efficiency. In this research we studied the performance of molecular mechanics generalized Born surface area (MM-GBSA), molecular mechanics Poisson-Boltzmann surface area (MM-PBSA), and solvated interaction energy (SIE) both in their virtual screening efficiency and their ability to predict experimentally determined binding affinities for five different protein targets. The protein-ligand complexes were derived with two different app…
Fast Techniques for Mosaic Rendering
2005
Use of accelerometers and gyros for hip and knee angle estimation
2013
In this paper a wearable sensor system, consisting of accelerometers and gyros, has been studied to estimate hip and knee angles. The proposed algorithm, developed in order to avoid the error accumulation due to gyroscopes drift, has been tested on angle measurement of the hip and knee of a commercial device for assisted gait. The results have shown a good accuracy of the angles estimation, also in high angle rate movement
A novel technique for opus vermiculatum mosaic rendering
2006
In this paper we present a method to generate a digital mosaic starting from a raster input image. Mosaics generation of artistic quality is challenging. The basic elements, the tiles, typically small polygons, must be packed tightly, emphasizing orientations chosen by the artist. An adhoc boundaries detection have to be performed according to the directional guidelines. Different mosaic styles can be automatically rendered, depending on artistic techniques considered (“opus musivum”, “opus vermiculatum”, etc.). The proposed method is able to reproduce the colors of the original image emphasizing relevant boundaries by placing tiles along their direction. The boundaries detection is based o…