Medical Image Perception Society 2009 - Day two

Session 6. Performance Measurement II. Chair: Matthew Freedman, MD, MBA

• Coding of FDG Intensity as a 3-D Rendered Height Mapping to Improve Fusion Display of Co-Registered PET-CT Images. RM Shah, C Wood, YP Hu, & LS Zuckier

• Revisiting the General Three-class ROC Theory. X He & EC Frey

• Estimation of AUC from Normally Distributed Rating Data with Known Variance Ratio. A Wunderlich & F Noo

• Using the Mean-to-Variance Ratio as a Diagnostic for Unacceptably Improper Binormal ROC Curves. SL Hillis & KS Berbaum

Session 7. Performance Measurement II. Chair: Stephen Hillis, PhD

• BI-RADS Data Should Not be Used to Estimate ROC Curves. Y Jiang & CE Metz
  
  
• Estimating the utility of screening mammography in large clinical studies. CK Abbey, JM Boone, & MP Eckstein
  
  
• Issues Related to the Definition of Image Contrast, DL Leong & PC Brennan

Session 8. Models of Perceptual processing. Chair: Yulei Jiang, PhD

• Channelized Hotelling Observers for Detection Tasks in Multi-Slice Images. L Platiša, B Goossens, E Vansteenkiste, A Badano & W Philips
  
  
• Channelized Hotelling observers adapted to irregular signals in breast tomosynthesis detection tasks. I Diaz, P Timberg, CK Abbey, MP Eckstein, FR Verdun, C Castella, FO Bochud
  
  
• Detecting Compression Artifacts in Virtual Pathology Images Using a Visual Discrimination Model. J Johnson & EA Krupinski
  
  
• Automatic MRI Acquisition Parameters Optimization Using HVS-Based Maps. J Jacobsen, P Irarrázabal, & C Tejos
  
  
• Parametric Assessment of Lesion Detection Using a Pre-whitened Matched Filter on Projected Breast CT Images. N Packard, CK Abbey, & JM Boone
  
  
• Model Observers for Complex Discrimination Tasks: Deployment Assessment of Multiple Coronary Stents. S Zhang, CK Abbey, X Da, JS Whiting, & MP Eckstein

Session 9. Special Invited Session on Neuroscience and Medical Image Perception. Chair: Miguel Eckstein, PhD

• Natural image statistics and visual coding. BA Olshausen

• Decoding Information Processing When Attention Fails: An Electrophysiological Approach. B Giesbrecht

• Some Neural Bases of Radiological Expertise. SA Engel

Medical Image Perception Society 2009 - Day one

The first day of the Medical Image Perception Society conference, held biannual, this year in Santa Barbara was filled with interesting talks. Plenty of research utilizing eye tracking as a means of obtaining data. The conference is hosted by Craig Abbey and Miguel Eckstein at the Department of Psychology at the University of California, Santa Barbara in cooperation with Elizabeth Krupinski (book1 , book2) from University of Arizona whom has performed extensive research on eye movements (among other things) in relation to medical imaging and radiology.

Session 1. Visual Search. Chair: Claudia Mello-Thoms, PhD

• Seeing trouble in a flash: Discrimination of normal from abnormal mammograms with brief exposure. KK Evans (current), D Georgian-Smith, R Birdwell, & JM Wolfe

• Mapping Eye Movements in Three-Dimensions: Analyzing Gaze Paths when Interpreting Volumetric Chest CT Data. M Tall, DL Ly, F Schmitzberger, D Rasooly, TJ Kim, JE Roos, DS Paik, S Napel, & GD Rubin

• Measuring Axial CTC Interaction. P Phillips

• Using eye-tracking to study diagnostic process during MRI scanning. C Cavaro-Ménard, J-Y Tanguy, & P Le Callet

Session 2. Visual Search. Chair: Elizabeth Krupinski, PhD

• Visual Search Characteristics of Pathology Residents Reading Dermatopathology Slides. J Law & C Mello-Thoms

• Are you a good eye-witness? Perceptual differences between physicians and lay people. C Mello-Thoms

• Eye movements and computer-based mammographic interpretation training. Y Chen & A Gale

Session 3. Perceptual Effects. Chair: David Manning, PhD

• Nuisance levels of noise effects Radiologists Performance. MF Mc Entee, A O'Beirne, J Ryan, R Toomey, M Evanoff, D Chakraborty, D Manning, & PC. Brennan

• Observer Performance in Stroke Interpretation: The Influence of Experience and Clinical Information in Multidimensional Magnetic Resonance Imaging. L Cooper, A Gale, J Saada, S Gedela, H Scott, & A Toms

• Interpretation of wrist radiographs: A comparison between final year medical and radiography students. L Hutchinson, P Brennan & L Rainford

• Tumor measurement for revised TNM staging of lung cancer. FL Jacobson, A Sitek, D Getty, & SE Seltzer

• Does Reader Visual Fatigue Impact Performance? EA Krupinski & KS Berbaum

• Ambient Temperature is an Important Consideration in the Radiology Reading Room. MF Mc Entee & S Gafoor

Session 4. Performance Measurement I. Chair: Dev Chakraborty, PhD

• Perceptual indicators of the holistic view in pulmonary nodule detection. MW Pietrzyk, DJ Manning, T Donovan, & Alan Dix

• An e-learning tutorial demonstrates significant improvements in ROC performance amongst naive observers in breast image interpretation. PBL Soh, PC Brennan, A Poulos, W Reed

• Is n ROC-type response Truly always better than A Binary Response? D Gur, AI Bandos, HE Rockette, ML Zuley, CM Hakim, DM Chough, MA Ganott

• Recognition of Images in Reader Studies: How Well Can We Predict Which Will Be Remembered? T Miner Haygood, P O’Sullivan, J Ryan, E Galvan, J-M Yamal, M Evanoff, M McEntee, J Madewell, C Sandler, E Lano, & P Brennan

Session 5. Performance Measurement I. Chair: Alastair Gale, PhD

• New classes of models with monotonic likelihood ratios. F Samuelson

• Sample size estimation procedure for free-response (FROC) studies. DP Chakraborty & M Bath

• Comparison of Four Methods (ROC, JAFROC, IDCA, and ROI) for Analysis of Free Response Clinical Data. F Zanca, DP Chakraborty, J Jacobs, G. Marchal, and H Bosmans

Feel free to post additional links in the comments. Slides will be posted as they become available.

DoCoMo EOG update

While eye movement detection using EOG is nothing new the latest demonstration by Japanese NTT DoCoMo illustrates recent developments in the field. The innovation here is the form factor which is quite impressive. Typically EOG is detected using electrodes placed around the eyes as in Andreas Bullings prototype demonstrated at CHI 09 in Boston. Now it can be done using tiny sensors inside the ear. Just compare it to the prototype demonstrated last year!







Thanks Roman for the links!

Wearable Augmented Reality System using Gaze Interaction (Park, Lee & Choi)

Came across this paper on a wearable system that employs a small eye tracker and a head mounted display for augmented reality. I've previously posted a video on the same system. It's a future technology with great potential, only imagination sets the limit here. There is a lot of progress in image/object recognition and location awareness taking place right now (with all the associated non-trivial problems to solve!)


Abstract
"Undisturbed interaction is essential to provide immersive AR environments. There have been a lot of approaches to interact with VEs (virtual environments) so far, especially in hand metaphor. When the user‟s hands are being used for hand-based work such as maintenance and repair, necessity of alternative interaction technique has arisen. In recent research, hands-free gaze information is adopted to AR to perform original actions in concurrence with interaction. [3, 4]. There has been little progress on that research, still at a pilot study in a laboratory setting. In this paper, we introduce such a simple WARS(wearable augmented reality system) equipped with an HMD, scene camera, eye tracker. We propose „Aging‟ technique improving traditional dwell-time selection, demonstrate AR gallery – dynamic exhibition space with wearable system."

• Park, H. M., Seok Han Lee, and Jong Soo Choi 2008. Wearable augmented reality system using gaze interaction. In Proceedings of the 2008 7th IEEE/ACM international Symposium on Mixed and Augmented Reality - Volume 00 (September 15 - 18, 2008). Symposium on Mixed and Augmented Reality. IEEE Computer Society, Washington, DC, 175-176. DOI= http://dx.doi.org/10.1109/ISMAR.2008.4637353

The EyeWriter project

For some time I've been following the EyeWriter project which aims at enabling Tony, who has ALS, to draw graffiti using eye gaze alone. The open source eye tracker is available at Google code and is based on C++, OpenFrameworks and OpenCV. The current version supports basic pupil tracking based on image thresholding and blob detection but they are aiming for remote tracking using IR glints. Keep up the great work guys!

The Eyewriter from Evan Roth on Vimeo.

eyewriter tracking software walkthrough from thesystemis on Vimeo.

More information is found at http://fffff.at/eyewriter/

GaZIR: Gaze-based Zooming Interface for Image Retrieval (Kozma L., Klami A., Kaski S., 2009)

From the Helsinki Institute for Information Technology, Finland, comes a research prototype called GaZIR for gaze based image retrieval built by Laszlo Kozma, Arto Klami and Samuel Kaski. The GaZIR prototype uses a light-weight logistic regression model as a mechanism for predicting relevance based on eye movement data (such as viewing time, revisit counts, fixation length etc.) All occurring on-line in real time. The system is build around the PicSOM (paper) retrieval engine which is based on tree structured self-organizing maps (TS-SOMs). When provided a set of reference images the PicSOM engine goes online to download a set of similar images (based on color, texture or shape)

Abstract
"We introduce GaZIR, a gaze-based interface for browsing and searching for images. The system computes on-line predictions of relevance of images based on implicit feedback, and when the user zooms in, the images predicted to be the most relevant are brought out. The key novelty is that the relevance feedback is inferred from implicit cues obtained in real-time from the gaze pattern, using an estimator learned during a separate training phase. The natural zooming interface can be connected to any content-based information retrieval engine operating on user feedback. We show with experiments on one engine that there is sufficient amount of information in the gaze patterns to make the estimated relevance feedback a viable choice to complement or even replace explicit feedback by pointing-and-clicking."

Fig1. "Screenshot of the GaZIR interface. Relevance feedback gathered from outer rings influences the images retrieved for the inner rings, and the user can zoom in to reveal more rings."

Fig2. "Precision-recall and ROC curves for userindependent relevance prediction model. The predictions (solid line) are clearly above the baseline of random ranking (dash-dotted line), showing that relevance of images can be predicted from eye movements. The retrieval accuracy is also above the baseline provided by a naive model making a binary relevance judgement based on whether the image was viewed or not (dashed line), demonstrating the gain from more advanced gaze modeling."

Fig 3. "Retrieval performance in real user experiments. The bars indicate the proportion of relevant images shown during the search in six different search tasks for three different feedback methods. Explicit denotes the standard point-and-click feedback, predicted means implicit feedback inferred from gaze, and random is the baseline of providing random feedback. In all cases both actual feedback types outperform the baseline, but the relative performance of explicit and implicit feedback depends on the search task."

• László Kozma, Arto Klami, and Samuel Kaski: GaZIR: Gaze-based Zooming Interface for Image Retrieval. To appear in Proceedings of 11th Conference on Multimodal Interfaces and The Sixth Workshop on Machine Learning for Multimodal Interaction (ICMI-MLMI), Boston, MA, USA, Novermber 2-6, 2009. (abstract, pdf)

An Adaptive Algorithm for Fixation, Saccade, and Glissade Detection in Eye-Tracking Data (Nyström M. & Holmqvist K, 2009)

From Markus Nyström and Kenneth Holmqvist at the Lund University Humanities Lab (HumLab) in Sweden comes an interesting paper on a novel algorithm that is capable of detecting glissades (aka dynamic overshoot) in eye tracker data. These are wobbling eye movements often found at the end of saccades and has previously been considered errors in saccadic programming with limited value. What ever their function is the phenomena does exists and should be accounted for. The paper reports finding glissades following half of all saccades while reading or viewing scenes, and has an average duration of 24 ms. This is work is important as it extends the default categorization of eye movement e.g. fixation, saccade, smooth pursuit, and blink. The algorithm is based on velocity saccade detection and is driven by data while containing a limited number of subjective settings. The algorithm contains a number of improvements such as thresholds for peak- and saccade onset/offset detection, adaptive threshold adjustment based on local noise levels, physical constraints on eye-movements to exclude noise and jitter, and new recommendations for minimum allowed fixation and saccade duration. Also, important to note that the data was obtained using a high-speed 1250 Hz SMI system, how the algorithm performs on a typical remote tracker running at 50-250Hz has yet to be defined.

• Nyström, M. & Holmqvist, K., "An Adaptive Algorithm for Fixation, Saccade, and Glissade Detection in Eye-Tracking Data", Behavior Research Methods.
  
  
• Download Matlab source code for the algorithm (version 1.0)

Psychnology Journal: Gaze control for work and play

"PsychNology Journal (ISSN 1720-7525) is a quadrimestral, international, peer-reviewed journal on the relationship between humans and technology. The name 'PsychNology' emphasizes its multidisciplinary interest in all issues related to the human adoption and development of technologies. Its broad scope allows to host in a sole venue advances and ideas that would otherwise remain confined within separate communities or disciplines. PNJ is an independent, electronic publication that leaves the copyright to authors, and provides wide accessibility to their papers through the Internet and several indexing and abstracting services including PsycInfo and EBSCO."

The Psychnology Journal Special edition on Gaze control for work and play is now available online. It contains some of the highlights from the Cogain conference last year in an extended journal format. For the COGAIN people this is old news, for the rest it's hopefully interesting stuff. The NeoVisus prototype I presented in Prague should have appeared but unfortunately did not have the time to make the necessary changes. More information on the scrollable keyboard and text entry by gaze in general is available in Päivi's excellent Ph.D thesis. Also, rumor has it that Javier San Agustin's Ph.D thesis gaze interaction and a low-cost alternative is getting closer to D-day. We're all looking forward to it, hang in there mate =)

• Predicting preference from fixations
  Mackenzie G. Glaholt, Mei-Chun Wu, Eyal M. Reingold

• Scrollable Keyboards for Casual Eye Typing
  Oleg Špakov, Päivi Majaranta

• Hands Free Interaction with Virtual Information in a Real Environment: Eye Gaze as an Interaction Tool in an Augmented Reality System
  Susanna Nilsson, Torbjörn Gustafsson, Per Carleberg

• Gaze beats mouse: A case study on a gaze-controlled breakout
  Michael Dorr, Laura Pomarjanschi, Erhardt Barth

• Evaluation of the Potential of Gaze Input for Game Interaction
  Javier San Agustin, Julio C. Mateo, John Paulin Hansen, Arantxa Villanueva

A geometric approach to remote eye tracking (Villanueva et al, 2009)

Came across this paper today, it's good news and a great achievement, especially since consumer products for recording high definition over a plain USB port has begun to appear. For example the upcoming Microsoft Lifecam Cinema HD provides 1,280 x 720 at 30 frames per second. This is to be released on September 9th at a reasonable US$ 80. Hopefully it will allow a simple modification to remove the infrared blocking filter. Things are looking better and better for low-cost eye tracking, keep up the excellent work, it will make a huge difference for all of us.

Abstract
"This paper presents a principled analysis of various combinations of image features to determine their suitability for remote eye tracking. It begins by reviewing the basic theory underlying the connection between eye image and gaze direction. Then a set of approaches is proposed based on different combinations of well-known features and their behaviour is valuated, taking into account various additional criteria such as free head movement, and minimum hardware and calibration requirements. The paper proposes a final method based on multiple glints and the pupil centre; the method is evaluated experimentally. Future trends in eye tracking technology are also discussed."


The algorithms were implemented in C++ running on a Windows PC equipped with a Pentium 4 processor at 3 GHz and 1 GB of Ram. The camera of choice delivers 15 frames per second at 1280 x 1024. Optimal distance from screen is 60 cm which is rather typical for remote eye trackers. This provides a track-box volume of 20 x 20 x 20 cm. Within this area the algorithms produce an average accuracy of 1.57 degrees. A 1 degree accuracy may be achieved obtained if the head is the same position as it was during calibration. Moving the head parallel to the monitor plane increases error by 0.2 - 0.4 deg. while moving closer or further away introduces a larger error between 1-1.5 degrees (mainly due to camera focus range). Note that no temporal filtering was used in the reporting. All-in-all these results are not so far from what typical remote systems produce.


The limitation of 15 fps stems from the frame rate of the camera, the software itself is able to process +50 images per second on the specified machine. Leaving it to our imagination what frame rates may be achieved with a fast Intel Core i7 processor with four cores.

• A. Villanueva, G. Daunys, D. Hansen, M. Böhme, R. Cabeza, A. Meyer, and E. Barth, "A geometric approach to remote eye tracking," Universal Access in the Information Society. [Online]. Available: http://dx.doi.org/10.1007/s10209-009-0149-0

COGAIN Student Competition Results

Lasse Farnung Laursen, a Ph.D student with the Department of Informatics and Mathematical Modeling at the Technical University of Denmark, won this years COGAIN student competition with the leisure application called GazeTrain.

"GazeTrain (illustrated in the screenshot below) is an action oriented puzzle game, that can be controlled by eye movements. In GazeTrain you must guide a train by placing track tiles in front of it. As you guide the train, you must collect various cargo and drop them off at the nearest city thereby earning money. For further details regarding how to play the game, we encourage you to read the tutorial accessible from the main menu. The game is quite customizable as the dwell time and several other parameters can be adjusted to best suit your play-style." (Source)

The GazeTrain game.

Runner ups, sharing the second place were

Music Editor, developed by Ainhoa Yera Gil, Public University of Navarre, Spain. Music Editor is a gaze-operated application that allows the user to compose, edit and play music by eye movements. The reviewers appreciated it that "a user can not only play but can actually create something" and that "Music Editor is well suited for gaze control".

Gaze Based Sudoku, developed by Juha Hjelm and Mari Pesonen, University of Tampere, Finland. The game can be operated by eye movements and it has three difficulty levels. Reviewers especially appreciated how "the separation between viewing and controlling and between sudoku grid and number selection panel is solved" and that the game "has no time constraints" so it is "relaxing" to play.