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Intra-operative support via augmented reality techniques in endoscopic surgery

computer aided surgery : official journal of the International Society for computer Aided Surgery 2003年第6期8卷 310-5页

作者： Uli Bockholt Alexander Bisler Mario Becker Wolfgang Müller-Wittig Gerrit Voss Fraunhofer Institute for Computer Graphics (Fraunhofer-IGD) Department of Visualization & Virtual Reality Darmstadt Germany. bockholt@igd.fhg.de

computer assisted operation planning systems are gaining increasing recognition in the field of surgery. These systems offer new possibilities for preparing an intervention, with the goal of reducing the amount of expensive operating-room time required for the intervention. The safest and most effective surgical approach should always be selected, but it is often difficult to transfer the output of the planning system to the intra-operative situation so that the planning results can be considered during the actual intervention. At the Fraunhofer Institute for computer graphics (IGD) in Darmstadt and the Centre for Advanced Media Technology (CAMTech) in Singapore methods are being developed to bridge the gap between the external planning session and the intra-operative case: Augmented Reality (AR) techniques are used to overlay preoperative scanned image data, as well as results of the planning session, on the operation field.

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Remote computing environment compensating for brain shift

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computer Aided Surgery 2003年第4期8卷 169-179页

作者： Hastreiter, Peter Engel, Klaus Soza, Grzegorz Wolf, Matthias Ganslandt, Oliver Fahlbusch, Rudolf Greiner, Gnther Ximsky, Christopher Department of Neurosurgery Neurocenter Friedrich Alexander University of Erlangen-Nuremberg D-91054 Erlangen Schwabachanlage 6. Germany Computer Graphics Group University of Erlangen-Nuremberg Erlangen Germany Visualization and Interactive Systems Group University of Stuttgart Erlangen Germany Knowledge Processing Group Bavarian Research Center for Knowledge-Based Systems Erlangen Germany

Objective: Anatomical and functional image data become invalid during an operation due to brain shift. Compensation is achieved by using intraoperative imaging to update anatomical information. To accelerate the registration and visualization of pre- and intraoperative image data, the presented work focuses on remote computing capabilities. The underlying framework efficiently combines local desktop computers and remote high-end graphics workstations exploiting expensive hardware. Methods: By performing all computations on the remote computer, the MR volumes are rigidly aligned via voxel-based registration. Using graphics hardware for acceleration, all interpolation operations are performed with 3D texture-mapping hardware. A new approach then transforms functional markers from preoperative measurements to the intraoperative situation using an automatic tracking algorithm to identify corresponding sulci. Communicating Java viewers are suggested for analyzing the results interactively on a local computer, with all calculations being performed exclusively on the remote computer. Results: The suggested approach was successfully applied in S cases using MR data containing functional markers of MEG and fMRI measurements identifying eloquent brain areas. Remote large-scale graphics hardware was thereby efficiently made available for fast registration and interactive direct volume rendering in neurosurgery. Conclusion: Overall, the presented framework demonstrates efficient access of expensive high- end hardware remotely controlled by thin clients, and further emphasizes the need to compensate for brain shift in functional neuronavigation. © 2003 Informa UK Ltd All rights reserved.

关键词： 3D visualization brain shift registration remote computing

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Novel uses of Pinch Gloves™ for virtual environment interaction techniques

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Virtual Reality 2002年第3期6卷 122-129页

作者： Bowman, D.A. Wingrave, C.A. Campbell, J.M. Ly, V.Q. Rhoton, C.J. Department of Computer Science Virginia Tech. Blacksburg VA United States College of Computing Graphics Visualization and Usability Center Georgia Institute of Technology GA United States Department of Computer Science (0106) Virginia Tech. Blacksburg VA 24061 United States

The usability of three-dimensional (3D) interaction techniques depends upon both the interface software and the physical devices used. However, little research has addressed the issue of mapping 3D input devices to interaction techniques and applications. This is especially crucial in the field of Virtual Environments (VEs), where there exists a wide range of potential 3D input devices. In this paper, we discuss the use of Pinch Gloves™ - gloves that report contact between two or more fingers - as input devices for VE systems. We begin with an analysis of the advantages and disadvantages of the gloves as a 3D input device. Next, we present a broad overview of three novel interaction techniques we have developed using the gloves, including a menu system, a text input technique, and a two-handed navigation technique. All three of these techniques have been evaluated for both usability and task performance. Finally, we speculate on further uses for the gloves. © Springer-Verlag London Ltd.

关键词： 3D Input Devices Interaction Techniques Pinch Gloves Usability Evaluation Virtual Environments

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A model for the visualization exploration process

A model for the visualization exploration process

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VIS 2002, IEEE Visualisation 2002

作者： Jankun-Kelly, T.J. Ma, Kwan-Liu Gertz, Michael Visualization and Graphics Res. Grp. Center for IPIC University of California Davis CA 95616 United States Database and Information Syst. Group Computer Science Department University of California Davis CA 95616 United States

The current state of the art in visualization research places a strong emphasis on different techniques to derive insight from disparate types of data. However, little work has investigated the visualization process itself. The information content of the visualization process-the results, history, and relationships between those results-is addressed by this work. A characterization of the visualization process is discussed, leading to a general model of the visualization exploration process. The model, based upon a new parameter derivation calculus, can be used for automated reporting, analysis, or visualized directly. An XML-based language for expressing visualization sessions using the model is also described. These sessions can then be shared and reused by collaborators. The model, along with the XML representation, provides an effective means to utilize the information within the visualization process to further data exploration.

关键词： visualization

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A Study of Transfer Function Generation for Time-Varying Volume Data 2

A Study of Transfer Function Generation for Time-Varying Vol...

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2nd IEEE TCVG / Eurographics International Workshop on Volume graphics, VG 2001

作者： Jankun-Kelly, T.J. Ma, Kwan-Liu Visualization And Graphics Research Group Center For Image Processing And Integrated Computing University Of California Department Of Computer Science DavisCA95616 United States

ISBN: (纸本)321183737X

The proper usage and creation of transfer functions for time-varying data sets is an often ignored problem in volume visualization. Although methods and guidelines exist for time-invariant data, little formal study for the timevarying case has been performed. This paper examines this problem, and reports the study that we have conducted to determine how the dynamic behavior of time-varying data may be captured by a single or small set of transfer functions. The criteria which dictate when more than one transfer function is needed were also investigated. Four data sets with different temporal characteristics were used for our study. Results obtained using two different classes of methods are discussed, along with lessons learned. These methods, including a new multiresolution opacity map approach, can be used for semi-automatic generation of transfer functions to explore large-scale time-varying data sets. © VG 2001. All rights reserved.

关键词： Transfer functions

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Real-time out-of-core visualization of particle traces

Real-time out-of-core visualization of particle traces

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IEEE Symposium on Parallel and Large-Data visualization and graphics (PVG)

作者： R. Bruckschen F. Kuester B. Hamann K.I. Joy Visualization and Graphics Research Group Center for Image Processing and Integrated Computing Department of Computer Science University of California Davis CA USA Visualization and Interactive Systems Group Department of Electrical and Computer Engineering University of California Irvine CA USA

ISBN: (纸本)0780372239

visualization of particle traces provides intuitive and efficient means for the exploration and analysis of complex vector fields. The paper presents a method suitable for the real-time visualization of arbitrarily large time-varying vector fields in virtual environments. We describe an out-of-core scheme in which two distinct pre-processing and rendering components enable real-time data streaming and visualization. The presented approach yields low-latency application start-up times and small memory footprints. The described system was used to implement a "volumetric fog lance," which can emit up to 60000 particles into a flow field while maintaining an interactive frame rate of 60 frames per second. All algorithms were specifically designed to support commodity hardware. The proof-of-concept system is running on a low-cost Linux workstation equipped with a 120 GB E-IDE RAID (redundant array of inexpensive disk) system.

关键词： Data visualization Computational modeling Computational fluid dynamics Motion pictures Hardware computer graphics Interactive systems Image processing computer science Image analysis

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Compressed progressive meshes (vol 6, pg 79, 2000)

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IEEE TRANSACTIONS ON visualization AND computer graphics 2000年第2期6卷 190-192页

作者： Pajarola, R Rossignac, J Information and Computer Science Department University of California Irvine Graphics Visualization and Usablity Center Georgia Institute of Technology

Most systems that support visual interaction with 3D models use shape representations based on triangle meshes. The size of these representations imposes limits on applications for which complex 3D models must be accessed remotely. Techniques for simplifying and compressing 3D models reduce the transmission time. Multiresolution formats provide quick access to a crude model and then refine it progressively. Unfortunately, compared to the best nonprogressive compression methods, previously proposed progressive refinement techniques impose a significant overhead when the full resolution model must be downloaded. The CPM (Compressed Progressive Meshes) approach proposed here eliminates this overhead. It uses a new technique, which refines the topology of the mesh in batches, which each increase the number of vertices by up to 50 percent. Less than an amortized total of 4 bits per triangle encode where and how the topological refinements should be applied. We estimate the position of new vertices from the positions of their topological neighbors in the less refined mesh using a new estimator that leads to representations of vertex coordinates that are 50 percent more compact than previously reported progressive geometry compression techniques.

关键词： Triangle mesh compression Progressive Meshes Multiresolution Modeling Geometry Compression

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A spreadsheet interface for visualization exploration 00

A spreadsheet interface for visualization exploration

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Proceedings of the conference on visualization '00

作者： T. J. Jankun-Kelly Kwan-Liu Ma Computer Science Department Visualization and Graphics Research Group. Center for Image Processing and Integrated Computing University of California Davis CA

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Rhinosurgical therapy planning via endonasal airflow simulation†

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computer Aided Surgery 2000年第3期5卷

作者： Uli Bockholt Dipl.-Math. Gunter Mlynski M.D. Wolfgang Müller Dipl.-Inf. Gerrit Voss Dipl.-Inf. Darmstadt University of Technology Interactive Graphics Systems Group (GRIS) Darmstadt ENT-Clinic Ernst-Moritz-Arndt University Greifswald Greifswald and Fraunhofer Institute for Computer Graphics (Fraunhofer-IGD) Department of Visualization & Virtual Reality Darmstadt Germany

Nowadays, Computational Fluid Dynamics (CFD) methods play an important part in the production process of the automotive industry. Progress in recent years has made possible highly sophisticated airflow-simulation models that are used in engineering for optimization and verification of aerodynamics. The key purpose of the Simulation Tool for Airflow in the human Nose (STAN), developed at the Darmstadt University of Technology in cooperation with the University Hospital in Greifswald, is to use these techniques to support the rhinosurgeon in diagnosis and planning of therapy (Frühauf T, Mlynski G. Simulation and visualization of the air flow in the human nose. Proceedings of the First World Congress on Computational Medicine, Austin, Texas, 1994). A system has been developed that realizes a three-dimensional (3D) reconstruction of the endonasal cavities based on computer tomography (CT) scans. This semiautomatic reconstruction method requires minimal manual intervention. The surface model is used to create an unstructured 3D volume mesh suitable for finite volume simulations. In this way, an individual simulation based on patient-specific data can be realized. At the University Hospital in Greifswald, experimental investigations and measurements are made in nasal models to verify the simulation result. The goal of this project is to investigate individual nasal complaints and to detect respiratory disorders. The surgeon should be able to simulate the disordered respiration before performing a surgical procedure, and thereby increase the effectiveness of surgical planning. Comp Aid Surg 5:175–179 (2000). © 2000 Wiley-Liss, Inc.

关键词： biomechanical simulation computer-aided diagnosis computational biofluids rhinosurgery

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Real-time simulation of tissue deformation for the nasal endoscopy simulator (NES)

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computer Aided Surgery 1999年第5期4卷

作者： Uli Bockholt Dipl.-Math. Wolfgang Müller Dipl.-Inf. Gerrit Voss Dipl.-Inf. Ulrich Ecke M.D. Ludger Klimek M.D. Interactive Graphics Systems Group (GRIS) Darmstadt University of Technology Darmstadt Mainz University Hospital Mainz Germany Department of Visualization and Virtual Reality Fraunhofer Institute for Computer Graphics (Fraunhofer-IGD) Darmstadt Mainz University Hospital Mainz Germany Department of Otolaryngology Head and Neck Surgery Mainz University Hospital Mainz Germany

Endonasal sinus surgery requires a great amount of training before it can be adequately performed. The complicated anatomy involved, the proximity of relevant structures, and the variability of the anatomy due to inborn or iatrogenic variations make several complications possible. Today, cadaver dissections are the “gold standard” for surgical training. To overcome the drawbacks of traditional training methods, the Fraunhofer Institute for computer graphics is currently developing a highly interactive medical simulation system for nasal endoscopy and endonasal sinus surgery, in cooperation with the Mainz University Hospital. For the simulation of a rhinoscopic procedure, not only are the realization of the 3D interaction and the geometric representation of the anatomical structures necessary, but also a real-time simulation of the deformation behavior constrained by the instrument collisions. The challenge is to close the gap between a maximal degree of realism and the required real-time conditions. Comp Aid Surg 4:281–285 (1999). © 1999 Wiley-Liss, Inc.

关键词： surgical simulation skill training virtual reality soft tissue deformation rhinoscopic education

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