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Tim Poston

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I don't really fit this format.
I've been in and out of research institutes, universities and companies: currently working on graphics and interaction with Animoto.com. Academia recognises "papers" but not "patents", so some more flexible self-description is on my home page.
Address: Forus Health Pte Ltd
Bangalore

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David Pierre Leibovitz

Carleton University

University College Cork

Patrizio Frosini

Università di Bologna

Lancaster University

Duke University

Kansas State University

Armando Marques-Guedes

UNL - New University of Lisbon

Denis A. Coelho

Universidade da Beira Interior

University of Genova

José d'Encarnação

Universidade de Coimbra

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Papers by Tim Poston

Delaunay Triangulation as a New Coverage Measurement

by Tim Poston and Hassan Chizari

Sensors, 2011

Sensing and communication coverage are among the most important trade-offs in Wireless Sensor Net... more Sensing and communication coverage are among the most important trade-offs in Wireless Sensor Network (WSN) design. A minimum bound of sensing coverage is vital in scheduling, target tracking and redeployment phases, as well as providing communication coverage. Some methods measure the coverage as a percentage value, but detailed information has been missing. Two scenarios with equal coverage percentage may not have the same Quality of Coverage (QoC). In this paper, we propose a new coverage measurement method using Delaunay Triangulation (DT). This can provide the value for all coverage measurement tools. Moreover, it categorizes sensors as ‘fat’, ‘healthy’ or ‘thin’ to show the dense, optimal and scattered areas. It can also yield the largest empty area of sensors in the field. Simulation results show that the proposed DT method can achieve accurate coverage information, and provides many tools to compare QoC between different scenarios.

<title>Implicit function-based phantoms for evaluation of registration algorithms</title>

by Nithin Nagaraj and Tim Poston

Medical Imaging 2005: Image Processing, 2005

Medical image fusion is increasingly enhancing diagnostic accuracy by synergizing information fro... more Medical image fusion is increasingly enhancing diagnostic accuracy by synergizing information from multiple images, obtained by the same modality at different times or from complementary modalities such as structural information from CT and functional from PET. An active, crucial research topic in fusion is validation of the registration (point-to-point correspondence) used. Phantoms and other simulated studies are useful in the absence of, or as a preliminary to, definitive clinical tests. Software phantoms in specific have the added advantage of robustness, repeatability and reproducibility. Our virtual-lung-phantom-based scheme can test the accuracy of any registration algorithm and is flexible enough for added levels of complexity (addition of blur/anti-alias, rotate/warp, and modality-associated noise) to help evaluate the robustness of an image registration/fusion methodology. Such a framework extends easily to different anatomies. The feature of adding software-based fiducials both within and outside simulated anatomies prove more beneficial when compared to experiments using data from external fiducials on a patient. It would help the diagnosing clinician make a prudent choice of registration algorithm.

Method for modeling and rendering complex surfaces using local height maps

Design and Analysis of Tensegrity Structures

The Virtual Workbench: Dextrous VR

Virtual Reality Software And Technology - Proceedings of the VRST '94 Conference, 1994

The Virtual Workbench: Dextrous VR Timothy Poston and Luis Serra Centre for Information-Enhanced ... more

Interactive vessel tracing in volume data

Proceedings of the 1997 symposium on Interactive 3D graphics - SI3D '97, 1997

On many scales, volume data sets often lack the resolution to allow automatic network segmentatio... more On many scales, volume data sets often lack the resolution to allow automatic network segmentation, from blood vessels to molten rock channels; even where humans can see the net clearly. We introduce a precise and dextrous environment for users to transform perception to data, using a stereoscopic view for easy identification of vessels. Our tools exploit the reach-in handimmersion ergonomics of the Virtual Workbench to allow sustained productive work, and 3D-textured subvolumes to allow interactive vessel tracing in real time.

<title>Implicit function-based phantoms for evaluation of registration algorithms</title>

Medical Imaging 2005: Image Processing, 2005

Medical image fusion is increasingly enhancing diagnostic accuracy by synergizing information fro... more Medical image fusion is increasingly enhancing diagnostic accuracy by synergizing information from multiple images, obtained by the same modality at different times or from complementary modalities such as structural information from CT and functional from PET. An active, crucial research topic in fusion is validation of the registration (point-to-point correspondence) used. Phantoms and other simulated studies are useful in the absence of, or as a preliminary to, definitive clinical tests. Software phantoms in specific have the added advantage of robustness, repeatability and reproducibility. Our virtual-lung-phantom-based scheme can test the accuracy of any registration algorithm and is flexible enough for added levels of complexity (addition of blur/anti-alias, rotate/warp, and modality-associated noise) to help evaluate the robustness of an image registration/fusion methodology. Such a framework extends easily to different anatomies. The feature of adding software-based fiducials both within and outside simulated anatomies prove more beneficial when compared to experiments using data from external fiducials on a patient. It would help the diagnosing clinician make a prudent choice of registration algorithm.

Virtual Aristotelean physics

Proceedings of IEEE Virtual Reality Annual International Symposium, 1993

Aristotle&amp;amp;#39;s physics provides a coherent set of physical laws which predict physic... more Aristotle&amp;amp;#39;s physics provides a coherent set of physical laws which predict physical events less well than Newton&amp;amp;#39;s, but fit human expectations better. Embedded in a virtual reality, they thus provide a system which the user can more quickly learn to control, being more intuitive than Newton&amp;amp;#39;s laws and more consistent than ad hoc movement rules. Being simpler and cheaper to

Visibility volumes for interactive path optimization

The Visual Computer, 2008

We describe a real-time system that supports design of optimal flight paths over terrains. These ... more We describe a real-time system that supports design of optimal flight paths over terrains. These paths either maximize view coverage or minimize vehicle exposure to ground. A volume-rendered display of multi-viewpoint visibility and a haptic interface assists the user in selecting, assessing, and refining the computed flight path. We design a three-dimensional scalar field representing the visibility of a point above the terrain, describe an efficient algorithm to compute the visibility field, and develop visual and haptic schemes to interact with the visibility field. Given the origin and destination, the desired flight path is computed using an efficient simulation of an articulated rope under the influence of the visibility gradient. The simulation framework also accepts user input, via the haptic interface, thereby allowing manual refinement of the flight path.

Assessing suturing techniques using a virtual reality surgical simulator

Microsurgery, 2010

Advantages of virtual-reality simulators surgical skill assessment and training include more trai... more Advantages of virtual-reality simulators surgical skill assessment and training include more training time, no risk to patient, repeatable difficulty level, reliable feedback, without the resource demands, and ethical issues of animal-based training. We tested this for a key subtask and showed a strong link between skill in the simulator and in reality. Suturing performance was assessed for four groups of participants, including experienced surgeons and naive subjects, on a custom-made virtual-reality simulator. Each subject tried the experiment 30 times using five different types of needles to perform a standardized suture placement task. Traditional metrics of performance as well as new metrics enabled by our system were proposed, and the data indicate difference between trained and untrained performance. In all traditional parameters such as time, number of attempts, and motion quantity, the medical surgeons outperformed the other three groups, though differences were not significant. However, motion smoothness, penetration and exit angles, tear size areas, and orientation change were statistically significant in the trained group when compared with untrained group. This suggests that these parameters can be used in virtual microsurgery training.

The Brain Bench: virtual tools for stereotactic frame neurosurgery

Medical Image Analysis, 1997

We present a suite of neurosurgery supporting tools developed around (i) the Virtual Workbench, a... more We present a suite of neurosurgery supporting tools developed around (i) the Virtual Workbench, a productive environment for the control of 3-D data, in which delicate work can be performed for hours on end without strain, and (ii) the Electronic Brain Atlas, integrating the major print brain atlases in day-to-day clinical use. We describe in detail the Brain Bench, a surgical planning system for stereotactic frame neurosurgery. Its objective is to prepare faster plans; have a better and more accurate choice of target points; improve the avoidance of sensitive structures; have fewer sub-optimal frame attachments and speedier, more effective planning and training. If validated by a clinical study now under way, this will improve medical efficacy and reduce costs.

Dextrous virtual work

Communications of the ACM, 1996

A system for visualizing and manipulating medical images is detailed, with emphasis on interactio... more

Fuzzy Hough transform

by Tim Poston and Laszlo Koczy

Pattern Recognition Letters, 1994

July 1994 ~ Pattern Recognition Letters ELqEVIER Pattern Recognition Letters 15 ( 1994 ) 649-658 ... more

Interaction techniques for a virtual workspace

by John Waterworth and Tim Poston

Proceedings ICAT/VRST' …, Jan 1, 1995

Catastrophe theory and its applications

DOVER BOOKS ON MATHEMATICS AN INTROOUCTION TO LINEAR ALGEBRA ANO TENSORS, MA Akivis and VV Goldbe... more

Fuzzy geometry

... The vi, together with the line segments, define a regular n-sided polygon. We call such a pol... more

Nonlinear modeling of multistable perception

Behavioral Science, Jan 1, 1978

Multiresolution isosurface extraction with adaptive skeleton climbing

Computer Graphics Forum, Jan 1, 1998

Post-buckling behavior of a non-linearly hyperelastic thin rod with cross-section invariant under the dihedral group D n

Archive for rational mechanics and …, Jan 1, 1985

... with Cross-Section Invariant under the Dihedral Group Dn ERNESTO BUZANO, GIUSEPPE GEYMONAT &a... more

Cryptology: the mathematics of secure communication

The Mathematical …, Jan 1, 1979

Delaunay Triangulation as a New Coverage Measurement

by Tim Poston and Hassan Chizari

Sensors, 2011

Sensing and communication coverage are among the most important trade-offs in Wireless Sensor Net... more Sensing and communication coverage are among the most important trade-offs in Wireless Sensor Network (WSN) design. A minimum bound of sensing coverage is vital in scheduling, target tracking and redeployment phases, as well as providing communication coverage. Some methods measure the coverage as a percentage value, but detailed information has been missing. Two scenarios with equal coverage percentage may not have the same Quality of Coverage (QoC). In this paper, we propose a new coverage measurement method using Delaunay Triangulation (DT). This can provide the value for all coverage measurement tools. Moreover, it categorizes sensors as ‘fat’, ‘healthy’ or ‘thin’ to show the dense, optimal and scattered areas. It can also yield the largest empty area of sensors in the field. Simulation results show that the proposed DT method can achieve accurate coverage information, and provides many tools to compare QoC between different scenarios.

<title>Implicit function-based phantoms for evaluation of registration algorithms</title>

by Nithin Nagaraj and Tim Poston

Medical Imaging 2005: Image Processing, 2005

Medical image fusion is increasingly enhancing diagnostic accuracy by synergizing information fro... more Medical image fusion is increasingly enhancing diagnostic accuracy by synergizing information from multiple images, obtained by the same modality at different times or from complementary modalities such as structural information from CT and functional from PET. An active, crucial research topic in fusion is validation of the registration (point-to-point correspondence) used. Phantoms and other simulated studies are useful in the absence of, or as a preliminary to, definitive clinical tests. Software phantoms in specific have the added advantage of robustness, repeatability and reproducibility. Our virtual-lung-phantom-based scheme can test the accuracy of any registration algorithm and is flexible enough for added levels of complexity (addition of blur/anti-alias, rotate/warp, and modality-associated noise) to help evaluate the robustness of an image registration/fusion methodology. Such a framework extends easily to different anatomies. The feature of adding software-based fiducials both within and outside simulated anatomies prove more beneficial when compared to experiments using data from external fiducials on a patient. It would help the diagnosing clinician make a prudent choice of registration algorithm.

Method for modeling and rendering complex surfaces using local height maps

Design and Analysis of Tensegrity Structures

The Virtual Workbench: Dextrous VR

Virtual Reality Software And Technology - Proceedings of the VRST '94 Conference, 1994

The Virtual Workbench: Dextrous VR Timothy Poston and Luis Serra Centre for Information-Enhanced ... more

Interactive vessel tracing in volume data

Proceedings of the 1997 symposium on Interactive 3D graphics - SI3D '97, 1997

On many scales, volume data sets often lack the resolution to allow automatic network segmentatio... more On many scales, volume data sets often lack the resolution to allow automatic network segmentation, from blood vessels to molten rock channels; even where humans can see the net clearly. We introduce a precise and dextrous environment for users to transform perception to data, using a stereoscopic view for easy identification of vessels. Our tools exploit the reach-in handimmersion ergonomics of the Virtual Workbench to allow sustained productive work, and 3D-textured subvolumes to allow interactive vessel tracing in real time.

<title>Implicit function-based phantoms for evaluation of registration algorithms</title>

Medical Imaging 2005: Image Processing, 2005

Medical image fusion is increasingly enhancing diagnostic accuracy by synergizing information fro... more Medical image fusion is increasingly enhancing diagnostic accuracy by synergizing information from multiple images, obtained by the same modality at different times or from complementary modalities such as structural information from CT and functional from PET. An active, crucial research topic in fusion is validation of the registration (point-to-point correspondence) used. Phantoms and other simulated studies are useful in the absence of, or as a preliminary to, definitive clinical tests. Software phantoms in specific have the added advantage of robustness, repeatability and reproducibility. Our virtual-lung-phantom-based scheme can test the accuracy of any registration algorithm and is flexible enough for added levels of complexity (addition of blur/anti-alias, rotate/warp, and modality-associated noise) to help evaluate the robustness of an image registration/fusion methodology. Such a framework extends easily to different anatomies. The feature of adding software-based fiducials both within and outside simulated anatomies prove more beneficial when compared to experiments using data from external fiducials on a patient. It would help the diagnosing clinician make a prudent choice of registration algorithm.

Virtual Aristotelean physics

Proceedings of IEEE Virtual Reality Annual International Symposium, 1993

Aristotle&amp;amp;#39;s physics provides a coherent set of physical laws which predict physic... more Aristotle&amp;amp;#39;s physics provides a coherent set of physical laws which predict physical events less well than Newton&amp;amp;#39;s, but fit human expectations better. Embedded in a virtual reality, they thus provide a system which the user can more quickly learn to control, being more intuitive than Newton&amp;amp;#39;s laws and more consistent than ad hoc movement rules. Being simpler and cheaper to

Visibility volumes for interactive path optimization

The Visual Computer, 2008

We describe a real-time system that supports design of optimal flight paths over terrains. These ... more We describe a real-time system that supports design of optimal flight paths over terrains. These paths either maximize view coverage or minimize vehicle exposure to ground. A volume-rendered display of multi-viewpoint visibility and a haptic interface assists the user in selecting, assessing, and refining the computed flight path. We design a three-dimensional scalar field representing the visibility of a point above the terrain, describe an efficient algorithm to compute the visibility field, and develop visual and haptic schemes to interact with the visibility field. Given the origin and destination, the desired flight path is computed using an efficient simulation of an articulated rope under the influence of the visibility gradient. The simulation framework also accepts user input, via the haptic interface, thereby allowing manual refinement of the flight path.

Assessing suturing techniques using a virtual reality surgical simulator

Microsurgery, 2010

Advantages of virtual-reality simulators surgical skill assessment and training include more trai... more Advantages of virtual-reality simulators surgical skill assessment and training include more training time, no risk to patient, repeatable difficulty level, reliable feedback, without the resource demands, and ethical issues of animal-based training. We tested this for a key subtask and showed a strong link between skill in the simulator and in reality. Suturing performance was assessed for four groups of participants, including experienced surgeons and naive subjects, on a custom-made virtual-reality simulator. Each subject tried the experiment 30 times using five different types of needles to perform a standardized suture placement task. Traditional metrics of performance as well as new metrics enabled by our system were proposed, and the data indicate difference between trained and untrained performance. In all traditional parameters such as time, number of attempts, and motion quantity, the medical surgeons outperformed the other three groups, though differences were not significant. However, motion smoothness, penetration and exit angles, tear size areas, and orientation change were statistically significant in the trained group when compared with untrained group. This suggests that these parameters can be used in virtual microsurgery training.

The Brain Bench: virtual tools for stereotactic frame neurosurgery

Medical Image Analysis, 1997

We present a suite of neurosurgery supporting tools developed around (i) the Virtual Workbench, a... more We present a suite of neurosurgery supporting tools developed around (i) the Virtual Workbench, a productive environment for the control of 3-D data, in which delicate work can be performed for hours on end without strain, and (ii) the Electronic Brain Atlas, integrating the major print brain atlases in day-to-day clinical use. We describe in detail the Brain Bench, a surgical planning system for stereotactic frame neurosurgery. Its objective is to prepare faster plans; have a better and more accurate choice of target points; improve the avoidance of sensitive structures; have fewer sub-optimal frame attachments and speedier, more effective planning and training. If validated by a clinical study now under way, this will improve medical efficacy and reduce costs.

Dextrous virtual work

Communications of the ACM, 1996

A system for visualizing and manipulating medical images is detailed, with emphasis on interactio... more

Fuzzy Hough transform

by Tim Poston and Laszlo Koczy

Pattern Recognition Letters, 1994

July 1994 ~ Pattern Recognition Letters ELqEVIER Pattern Recognition Letters 15 ( 1994 ) 649-658 ... more

Interaction techniques for a virtual workspace

by John Waterworth and Tim Poston

Proceedings ICAT/VRST' …, Jan 1, 1995

Catastrophe theory and its applications

DOVER BOOKS ON MATHEMATICS AN INTROOUCTION TO LINEAR ALGEBRA ANO TENSORS, MA Akivis and VV Goldbe... more

Fuzzy geometry

... The vi, together with the line segments, define a regular n-sided polygon. We call such a pol... more

Nonlinear modeling of multistable perception

Behavioral Science, Jan 1, 1978

Multiresolution isosurface extraction with adaptive skeleton climbing

Computer Graphics Forum, Jan 1, 1998

Post-buckling behavior of a non-linearly hyperelastic thin rod with cross-section invariant under the dihedral group D n

Archive for rational mechanics and …, Jan 1, 1985

... with Cross-Section Invariant under the Dihedral Group Dn ERNESTO BUZANO, GIUSEPPE GEYMONAT &a... more

Cryptology: the mathematics of secure communication

The Mathematical …, Jan 1, 1979