Identification of Circular Patterns in Capsule Endoscopy Bubble Frames

Abstract

Abstract
Background: A significant number of frames captured by the wireless capsule endoscopy are
involved with varying amounts of bubbles. Whereas different studies have considered bubbles as
nonuseful agents due to the fact that they reduce the visualization quality of the small intestine
mucosa, this research aims to develop a practical way of assessing the rheological capability of
the circular bubbles as a suggestion for future clinical diagnostic purposes. Methods: From the
Kvasir?capsule endoscopy dataset, frames with varying levels of bubble engagements were chosen
in two categories based on bubble size. Border reflections are present on the edges of round?shaped
bubbles in their boundaries, and in the frequency domain, high-frequency bands correspond to these
edges in the spatial domain. The first step is about high-pass filtering of border reflections using
wavelet transform (WT) and Differential of Gaussian, and the second step is related to applying the
Fast Circlet Transform (FCT) and the Hough transform as circle detection tools on extracted borders
and evaluating the distribution and abundance of all bubbles with the variety of radii. Results:
Border’s extraction using WT as a preprocessing approach makes it easier for circle detection tool for
better concentration on high?frequency circular patterns. Consequently, applying FCT with predefined
parameters can specify the variety and range of radius and the abundance for all bubbles in an image.
The overall discrimination factor (ODF) of 15.01, and 7.1 showing distinct bubble distributions in
the gastrointestinal (GI) tract. The discrimination in ODF from datasets 1-2 suggests a relationship
between the rheological properties of bubbles and their coverage area plus their abundance,
highlighting the WT and FCT performance in determining bubbles’ distributions for diagnostic
objectives. Conclusion: The implementation of an object?oriented attitude in gastrointestinal analysis
makes it intelligible for gastroenterologists to approximate the constituent features of intra?intestinal
fluids. this can’t be evaluated until the bubbles are considered as non?useful agents. The obtained
results from the datasets proved that the difference between the calculated ODF can be used as an
indicator for the quality estimation of intraintestinal fluids’ rheological features like viscosity, which
helps gastroenterologists evaluate the quality of patient digestion.