2006
C. Benthin, I. Wald, P. Slusallek.
Techniques for Interactive Ray Tracing of Bezier Surfaces, In Journal of Graphics Tools, Vol. 11, No. 2, pp. 1--16. 2006.
C. Benthin, I. Wald, M. Scherbaum, H. Friedrich.
Ray Tracing on the CELL Processor, In Proceedings of the 2006 IEEE Symposium on Interactive Ray Tracing, pp. 25--32. 2006.
F.F. Bernardon, S.P. Callahan, J.L.D. Comba, C.T. Silva.
Interactive Volume Rendering of Unstructured Grids with Time-Varying Scalar Fields, In Proceedings of the Eurographics Symposium on Parallel Graphics and Visualization, pp. 51--58. 2006.
M. Berzins.
Is there Still More to Science than Simulation?, No. UUSCI-2006-031, SCI Institute, University of Utah, November, 2006.
M. Berzins.
Adaptive Polynomial Interpolation on Evenly Spaced Meshes, SCI Institute Technical Report, No. UUSCI-2006-033, University of Utah, 2006.
W. Bethel, C.R. Johnson, C.D. Hansen, S.G. Parker, A.R. Sanderson, C.T. Silva, X. Tricoche, V. Pascucci, H. Childs, J. Cohen, M. Duchaineau, D. Laney, P. Lindstrom, S. Ahern, J. Meredith, G. Ostrouchov, K. Joy, B. Hamann.
VACET: Proposed SciDAC2 Visualization and Analytics Center for Enabling Technologies, In J. Phys.: Conf. Ser., Vol. 46, pp. 561--569. 2006.
J. Bigler, A.J. Stephens, S.G. Parker.
Design for Parallel Interactive Ray Tracing Systems, SCI Institute Technical Report, No. UUSCI-2006-027, University of Utah, 2006.
J. Bigler, J. Guilkey, C. Gribble, C.D. Hansen, S.G. Parker.
A Case Study: Visualizing Material Point Method Data, In Proceedings of Euro Vis 2006, pp. 299--306, 377. May, 2006.
J. Bigler, A.J. Stephens, S.G. Parker.
Design for Parallel Interactive Ray Tracing Systems, In Proceedings of The IEEE Symposium on Interactive Ray Tracing, pp. 187--196. 2006.
S. Boulos, D. Edwards, J.D. Lacewell, J.M. Kniss, J. Kautz, P. Shirley, I. Wald.
Interactive Distribution Ray Tracing, SCI Institute Technical Report, No. UUSCI-2006-022, University of Utah, 2006.
S. Boulos, I. Wald, P. Shirley.
Geometric and Arithmetic Culling Methods for Entire Ray Packets, School of Computing Technical Report, No. UUCS-06-010, School of Computing, University of Utah, 2006.
P.-T. Bremer, W. Cabot, A. Cook, D. Laney, A. Mascarenhas, P. Miller, V. Pascucci.
Understanding the Structure of the Turbulent Mixing Layer in Hydrodynamic Instabilities, In Proceedings of SciDAC 2006 -- Scientific Discovery Through Advanced Computing, Denver, CO, USA, Vol. 46, Journal of Physics Conference Series, pp. 556--560. June, 2006.
S. Browd, L.J. Healy, G. Dobie, J.T. Johnson III, G.M. Jones, L.F. Rodriguez, D.L. Brockmeyer.
Morphometric and Qualitative Analysis of Congenital Occipitocervical Instability in Children: Implications for Down Syndrome Patients, In Journal of Neurosurgery: Pediatrics, Vol. 105, No. 1 , Journal of Neurosurgery Publishing Group, pp. 50--54. July, 2006.
DOI: 10.3171/ped.2006.105.1.50
C.R. Butson, C.B. Maks, C.C. McIntyre.
Sources and effects of electrode impedance during deep brain stimulation, In Clinical Neurophysiology, Vol. 117, No. 2, pp. 447--454. 2006.
DOI: 10.1016/j.clinph.2005.10.007
PubMed ID: 16376143
OBJECTIVE: Clinical impedance measurements for deep brain stimulation (DBS) electrodes in human patients are normally in the range 500-1500 Omega. DBS devices utilize voltage-controlled stimulation; therefore, the current delivered to the tissue is inversely proportional to the impedance. The goals of this study were to evaluate the effects of various electrical properties of the tissue medium and electrode-tissue interface on the impedance and to determine the impact of clinically relevant impedance variability on the volume of tissue activated (VTA) during DBS.
Keywords: Brain, Brain: physiology, Computer Simulation, Deep Brain Stimulation, Electric Conductivity, Electric Impedance, Electrodes, Humans, Imaging, Models, Neurological, Three-Dimensional
C.R. Butson, C.C. McIntyre.
Role of electrode design on the volume of tissue activated during deep brain stimulation, In Journal of Neural Engineering, Vol. 3, No. 1, pp. 1--8. March, 2006.
ISSN: 1741-2560
DOI: 10.1088/1741-2560/3/1/001
PubMed ID: 16510937
Deep brain stimulation (DBS) is an established clinical treatment for a range of neurological disorders. Depending on the disease state of the patient, different anatomical structures such as the ventral intermediate nucleus of the thalamus (VIM), the subthalamic nucleus or the globus pallidus are targeted for stimulation. However, the same electrode design is currently used in nearly all DBS applications, even though substantial morphological and anatomical differences exist between the various target nuclei. The fundamental goal of this study was to develop a theoretical understanding of the impact of changes in the DBS electrode contact geometry on the volume of tissue activated (VTA) during stimulation. Finite element models of the electrodes and surrounding medium were coupled to cable models of myelinated axons to predict the VTA as a function of stimulation parameter settings and electrode design. Clinical DBS electrodes have cylindrical contacts 1.27 mm in diameter (d) and 1.5 mm in height (h). Our results show that changes in contact height and diameter can substantially modulate the size and shape of the VTA, even when contact surface area is preserved. Electrode designs with a low aspect ratio (d/h) maximize the VTA by providing greater spread of the stimulation parallel to the electrode shaft without sacrificing lateral spread. The results of this study provide the foundation necessary to customize electrode design and VTA shape for specific anatomical targets, and an example is presented for the VIM. A range of opportunities exist to engineer DBS systems to maximize stimulation of the target area while minimizing stimulation of non-target areas. Therefore, it may be possible to improve therapeutic benefit and minimize side effects from DBS with the design of target-specific electrodes.
Keywords: Animals, Brain, Brain: physiology, Computer Simulation, Computer-Aided Design, Deep Brain Stimulation, Deep Brain Stimulation: instrumentation, Deep Brain Stimulation: methods, Electrodes, Equipment Design, Equipment Design: methods, Equipment Failure Analysis, Equipment Failure Analysis: methods, Humans, Implanted, Microelectrodes, Models, Neurological, Neurons, Neurons: physiology, Organ Size, Organ Size: physiology
S.P. Callahan, J. Freire, E. Santos, C.E. Scheidegger, C.T. Silva, H.T. Vo.
Managing the Evolution of Dataflows with VisTrails, In Proceedings of The 2006 IEEE Workshop on Workflow and Data Flow for Scientific Applications (SciFlow 2006), 2006.
S.P. Callahan, J. Freire, E. Santos, C. Scheidegger, C.T. Silva, H.T. Vo.
VisTrails: Visualization Meets Data Management, In Proceedings of the 2006 ACM SIGMOD/PODS Conference, pp. 745--747. 2006.
S.P. Callahan, J. Freire, E. Santos, C.E. Scheidegger, C.T. Silva, H.T. Vo.
Using Provenance to Streamline Data Exploration through Visualization, SCI Institute Technical Report, No. UUSCI-2006-016, University of Utah, 2006.
S.P. Callahan, L. Bavoil, V. Pascucci, C.T. Silva.
Progressive Volume Rendering of Large Unstructured Grids, SCI Institute Technical Report, No. UUSCI-2006-019, University of Utah, 2006.
S.P. Callahan, L. Bavoil, V. Pascucci, C.T. Silva.
Progressive Volume Rendering of Large Unstructured Grids, In IEEE Transactions on Visualization and Computer Graphics, Vol. 12, No. 5, Note: Updated version of UUSCI-2006-019., pp. 1307--1314. 2006.
DOI: 10.1109/TVCG.2006.171