The Experts below are selected from a list of 1224 Experts worldwide ranked by ideXlab platform

Jonathan C Silverstein - One of the best experts on this subject based on the ideXlab platform.

  • an optimized web based approach for collaborative stereoscopic Medical Visualization
    Journal of the American Medical Informatics Association, 2013
    Co-Authors: Mathias Kaspar, Nigel M Parsad, Jonathan C Silverstein
    Abstract:

    OBJECTIVE: Medical Visualization tools have traditionally been constrained to tethered imaging workstations or proprietary client viewers, typically part of hospital radiology systems. To improve accessibility to real-time, remote, interactive, stereoscopic Visualization and to enable collaboration among multiple viewing locations, we developed an open source approach requiring only a standard web browser with no added client-side software. MATERIALS AND METHODS: Our collaborative, web-based, stereoscopic, Visualization system, CoWebViz, has been used successfully for the past 2 years at the University of Chicago to teach immersive virtual anatomy classes. It is a server application that streams server-side Visualization applications to client front-ends, comprised solely of a standard web browser with no added software. RESULTS: We describe optimization considerations, usability, and performance results, which make CoWebViz practical for broad clinical use. We clarify technical advances including: enhanced threaded architecture, optimized Visualization distribution algorithms, a wide range of supported stereoscopic presentation technologies, and the salient theoretical and empirical network parameters that affect our web-based Visualization approach. DISCUSSION: The implementations demonstrate usability and performance benefits of a simple web-based approach for complex clinical Visualization scenarios. Using this approach overcomes technical challenges that require third-party web browser plug-ins, resulting in the most lightweight client. CONCLUSIONS: Compared to special software and hardware deployments, unmodified web browsers enhance remote user accessibility to interactive Medical Visualization. Whereas local hardware and software deployments may provide better interactivity than remote applications, our implementation demonstrates that a simplified, stable, client approach using standard web browsers is sufficient for high quality three-dimensional, stereoscopic, collaborative and interactive Visualization.

Mathias Kaspar - One of the best experts on this subject based on the ideXlab platform.

  • an optimized web based approach for collaborative stereoscopic Medical Visualization
    Journal of the American Medical Informatics Association, 2013
    Co-Authors: Mathias Kaspar, Nigel M Parsad, Jonathan C Silverstein
    Abstract:

    OBJECTIVE: Medical Visualization tools have traditionally been constrained to tethered imaging workstations or proprietary client viewers, typically part of hospital radiology systems. To improve accessibility to real-time, remote, interactive, stereoscopic Visualization and to enable collaboration among multiple viewing locations, we developed an open source approach requiring only a standard web browser with no added client-side software. MATERIALS AND METHODS: Our collaborative, web-based, stereoscopic, Visualization system, CoWebViz, has been used successfully for the past 2 years at the University of Chicago to teach immersive virtual anatomy classes. It is a server application that streams server-side Visualization applications to client front-ends, comprised solely of a standard web browser with no added software. RESULTS: We describe optimization considerations, usability, and performance results, which make CoWebViz practical for broad clinical use. We clarify technical advances including: enhanced threaded architecture, optimized Visualization distribution algorithms, a wide range of supported stereoscopic presentation technologies, and the salient theoretical and empirical network parameters that affect our web-based Visualization approach. DISCUSSION: The implementations demonstrate usability and performance benefits of a simple web-based approach for complex clinical Visualization scenarios. Using this approach overcomes technical challenges that require third-party web browser plug-ins, resulting in the most lightweight client. CONCLUSIONS: Compared to special software and hardware deployments, unmodified web browsers enhance remote user accessibility to interactive Medical Visualization. Whereas local hardware and software deployments may provide better interactivity than remote applications, our implementation demonstrates that a simplified, stable, client approach using standard web browsers is sufficient for high quality three-dimensional, stereoscopic, collaborative and interactive Visualization.

Thomas Bülow - One of the best experts on this subject based on the ideXlab platform.

  • A Radial Structure Tensor and Its Use for Shape-Encoding Medical Visualization of Tubular and Nodular Structures
    IEEE Transactions on Visualization and Computer Graphics, 2013
    Co-Authors: Rafael Wiemker, Tobias Klinder, Martin Bergtholdt, Kirsten Meetz, Ingwer C. Carlsen, Thomas Bülow
    Abstract:

    The concept of curvature and shape-based rendering is beneficial for Medical Visualization of CT and MRI image volumes. Color-coding of local shape properties derived from the analysis of the local Hessian can implicitly highlight tubular structures such as vessels and airways, and guide the attention to potentially malignant nodular structures such as tumors, enlarged lymph nodes, or aneurysms. For some clinical applications, however, the evaluation of the Hessian matrix does not yield satisfactory renderings, in particular for hollow structures such as airways, and densely embedded low contrast structures such as lymph nodes. Therefore, as a complement to Hessian-based shape-encoding rendering, this paper introduces a combination of an efficient sparse radial gradient sampling scheme in conjunction with a novel representation, the radial structure tensor (RST). As an extension of the well-known general structure tensor, which has only positive definite eigenvalues, the radial structure tensor correlates position and direction of the gradient vectors in a local neighborhood, and thus yields positive and negative eigenvalues which can be used to discriminate between different shapes. As Hessian-based rendering, also RST-based rendering is ideally suited for GPU implementation. Feedback from clinicians indicates that shape-encoding rendering can be an effective image navigation tool to aid diagnostic workflow and quality assurance.

Nigel M Parsad - One of the best experts on this subject based on the ideXlab platform.

  • an optimized web based approach for collaborative stereoscopic Medical Visualization
    Journal of the American Medical Informatics Association, 2013
    Co-Authors: Mathias Kaspar, Nigel M Parsad, Jonathan C Silverstein
    Abstract:

    OBJECTIVE: Medical Visualization tools have traditionally been constrained to tethered imaging workstations or proprietary client viewers, typically part of hospital radiology systems. To improve accessibility to real-time, remote, interactive, stereoscopic Visualization and to enable collaboration among multiple viewing locations, we developed an open source approach requiring only a standard web browser with no added client-side software. MATERIALS AND METHODS: Our collaborative, web-based, stereoscopic, Visualization system, CoWebViz, has been used successfully for the past 2 years at the University of Chicago to teach immersive virtual anatomy classes. It is a server application that streams server-side Visualization applications to client front-ends, comprised solely of a standard web browser with no added software. RESULTS: We describe optimization considerations, usability, and performance results, which make CoWebViz practical for broad clinical use. We clarify technical advances including: enhanced threaded architecture, optimized Visualization distribution algorithms, a wide range of supported stereoscopic presentation technologies, and the salient theoretical and empirical network parameters that affect our web-based Visualization approach. DISCUSSION: The implementations demonstrate usability and performance benefits of a simple web-based approach for complex clinical Visualization scenarios. Using this approach overcomes technical challenges that require third-party web browser plug-ins, resulting in the most lightweight client. CONCLUSIONS: Compared to special software and hardware deployments, unmodified web browsers enhance remote user accessibility to interactive Medical Visualization. Whereas local hardware and software deployments may provide better interactivity than remote applications, our implementation demonstrates that a simplified, stable, client approach using standard web browsers is sufficient for high quality three-dimensional, stereoscopic, collaborative and interactive Visualization.

Jannick P. Rolland - One of the best experts on this subject based on the ideXlab platform.

  • Modeling Real-Time 3-D Lung Deformations for Medical Visualization
    IEEE Transactions on Information Technology in Biomedicine, 2008
    Co-Authors: Anand P Santhanam, Celina Imielinska, Paul Davenport, Patrick Kupelian, Jannick P. Rolland
    Abstract:

    In this paper, we propose a physics-based and physiology-based approach for modeling real-time deformations of 3-D high-resolution polygonal lung models obtained from high-resolution computed tomography (HRCT) images of normal human subjects. The physics-based deformation operator is nonsymmetric, which accounts for the heterogeneous elastic properties of the lung tissue and spatial-dynamic flow properties of the air. An iterative approach is used to estimate the deformation with the deformation operator initialized based on the regional alveolar expandability, a key physiology-based parameter. The force applied on each surface node is based on the airflow pattern inside the lungs, which is known to be based on the orientation of the human subject. The validation of lung dynamics is done by resimulating the lung deformation and comparing it with HRCT data and computing force applied on each node derived from a 4-D HRCT dataset of a normal human subject using the proposed deformation operator and verifying its gradient with the orientation.

  • physically based deformation of high resolution 3d lung models for augmented reality based Medical Visualization
    Proceedings of the AMI-ARCS 2004 Workshop, 2004
    Co-Authors: Anand P Santhanam, Jannick P. Rolland, Cali M Fidopiastis, Felix G Hamzalup, Celina Imielinska
    Abstract:

    Visualization tools using Augmented Reality Environments are effective in applications related to Medical training, prognosis and expert interaction. Such Medical Visualization tools can also provide key visual insights on the physiology of deformable anatomical organs (e.g. lungs). In this paper we propose a deformation method that facilitates physically-based elastostatic deformations of 3D highresolution polygonal models. The implementation of the deformation method as a pre-computation approach is shown for a 3D high-resolution lung model. The deformation is represented as an integration of the applied force and the local elastic property assigned to the 3D lung model. The proposed deformation method shows faster convergence to equilibrium as compared to other physically-based simulation methods. The proposed method also accounts for the anisotropic tissue elastic properties. The transfer functions are formulated in such a way that they overcome stiffness effects during deformations.

  • A New Paradigm for Head-Mounted Display Technology: Application to Medical Visualization and Remote Collaborative Environments
    Novel Optical Systems Design and Optimization IV, 2001
    Co-Authors: Jannick P. Rolland, Yonggang Ha, L. Davis, Frank Biocca
    Abstract:

    Today advanced 3D virtual environments are mostly based on either a technology known as the cave or head-mounted displays. A new type of head-mounted display, which consists of a pair of miniature projection lenses and displays mounted on the helmet and retro-reflective sheeting materials placed strategically in the environment, has been proposed as an alternative to eyepiece optics types of displays. The novel concept and properties of the head- mounted projective display (HMPD) suggests solutions to part of the problems of state-of-art Visualization devices and make it extremely suitable for multiple-user collaborative environments. In this paper, we first review the concept of the HMPD and present the latest prototype developed. We then discuss its application to Medical Visualization and remote collaborative environments.

  • Optical Versus Video See-Through Head-Mounted Displays in Medical Visualization
    Presence: Teleoperators and Virtual Environments, 2000
    Co-Authors: Jannick P. Rolland, Henry Fuchs
    Abstract:

    We compare two technological approches to augmented reality for 3-D medicla Visualization; optical and video see-through devices. We provide a context to discuss the technology by reviewing several Medical applications of augmented-reality research effordt driven by real needs in the Medical field, both in the United States and in Europe. We then discuss the issues for each approach, optical versus video, for both a technology and human-factor point of view. Finally, we point to potentially promising future developments of such devices including eye tracking and multifocus planes capabilities, as well as hybrid optical/video technology.