Controlling the Display of Capsule Endoscopy Video for Diagnostic Assistance

Hai VU  Tomio ECHIGO  Ryusuke SAGAWA  Keiko YAGI  Masatsugu SHIBA  Kazuhide HIGUCHI  Tetsuo ARAKAWA  Yasushi YAGI  

IEICE TRANSACTIONS on Information and Systems   Vol.E92-D   No.3   pp.512-528
Publication Date: 2009/03/01
Online ISSN: 1745-1361
DOI: 10.1587/transinf.E92.D.512
Print ISSN: 0916-8532
Type of Manuscript: PAPER
Category: Biological Engineering
capsule endoscopy,  color similarity,  motion displacements,  video display rate control.,  

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Interpretations by physicians of capsule endoscopy image sequences captured over periods of 7-8 hours usually require 45 to 120 minutes of extreme concentration. This paper describes a novel method to reduce diagnostic time by automatically controlling the display frame rate. Unlike existing techniques, this method displays original images with no skipping of frames. The sequence can be played at a high frame rate in stable regions to save time. Then, in regions with rough changes, the speed is decreased to more conveniently ascertain suspicious findings. To realize such a system, cue information about the disparity of consecutive frames, including color similarity and motion displacements is extracted. A decision tree utilizes these features to classify the states of the image acquisitions. For each classified state, the delay time between frames is calculated by parametric functions. A scheme selecting the optimal parameters set determined from assessments by physicians is deployed. Experiments involved clinical evaluations to investigate the effectiveness of this method compared to a standard-view using an existing system. Results from logged action based analysis show that compared with an existing system the proposed method reduced diagnostic time to around 32.5 7 minutes per full sequence while the number of abnormalities found was similar. As well, physicians needed less effort because of the systems efficient operability. The results of the evaluations should convince physicians that they can safely use this method and obtain reduced diagnostic times.