Ryan Armstrong

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MobiVis is a visual analytics tools to aid in the process of processing and understanding complex relational data, such as social networks. At the core of these tools is the ability to filter complex networks structurally and semantically, which helps us discover clusters and patterns in the organization of social networks. Semantic filtering is obtained(More)
Image guidance can provide surgeons with valuable contextual information during a medical intervention. Often, image guidance systems require considerable infrastructure, setup-time, and operator experience to be utilized. Certain procedures performed at bedside are susceptible to navigational errors that can lead to complications. We present an application(More)
In this paper we present an information visualization approach for visualizing the intersection between multiple feature hierarchies. In cases where a dataset has multiple complex features of interest, especially ones that have been hierarchically clustered, it is often very difficult to grasp the commonalities between them. Understanding the overlap(More)
This paper describes the design and development of a software tool for the evaluation and training of surgical residents using an interactive, immersive, virtual environment. Our objective was to develop a tool to evaluate user spatial reasoning skills and knowledge in a neuroanatomical context, as well as to augment their performance through interactivity.(More)
As one of the most commonly performed neurosurgical procedures, ventriculostomy training simulators are becoming increasingly familiar features in research institutes and teaching facilities. Despite their widespread implementations and adoption, simulators to date have not fully explored the landscape of performance metrics that reflect surgical(More)
PURPOSE To report the results of early enteral feeding in patients with cancer after outpatient placement of a percutaneous fluoroscopy-guided gastrostomy (PFG). MATERIALS AND METHODS From January 2008 through December 2008, 121 consecutive patients with cancer underwent outpatient placement of a PFG for nutrition. Of these patients, 118 patients met(More)