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Capsule endoscopy (CE) is a widely used medical imaging tool for the diagnosis of gastrointestinal tract abnormalities like bleeding. However, CE captures a huge number of image frames, constituting a time-consuming and tedious task for medical experts to manually inspect. To address this issue, researchers have focused on computer-aided bleeding detection systems to automatically identify bleeding in real time. This paper presents a systematic review of the available state-of-the-art computer-aided bleeding detection algorithms for capsule endoscopy. The review was carried out by searching five different repositories (Scopus, PubMed, IEEE Xplore, ACM Digital Library, and ScienceDirect) for all original publications on computer-aided bleeding detection published between 2001 and 2023. The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) methodology was used to perform the review, and 147 full texts of scientific papers were reviewed. The contributions of this paper are: (I) a taxonomy for computer-aided bleeding detection algorithms for capsule endoscopy is identified; (II) the available state-of-the-art computer-aided bleeding detection algorithms, including various color spaces (RGB, HSV, etc.), feature extraction techniques, and classifiers, are discussed; and (III) the most effective algorithms for practical use are identified. Finally, the paper is concluded by providing future direction for computer-aided bleeding detection research. [ABSTRACT FROM AUTHOR]

Sulfuric acid (H2SO4) sensing is essential and demands a lot in manufacturing industries and real-life applications. In this study, a pentagonal-shaped photonic crystal fiber (PCF)-based plasmonic sensor is proposed to sense the concentration levels of H2SO4. This study is tested for 0%, 10%, 20%, 30%, and 40% H2SO4 mixture with water at 0.8 to1.8 μm wavelength range. For performance analysis of the sensor, a finite element method (FEM) based on COMSOL Multiphysics software is used. The sensor structure includes a large circular core and pentagonal-shaped cladding region. Because of the large circular core, the sensor achieved higher relative sensitivity which is 99.6% with negligible confinement loss (around 0 dB/m) and effective material loss (1.8 × 10−3 dB/cm) at 1.3 μm optimum wavelength condition. Also, the sensor fabrication complexity is less than others because of core and all the air holes of cladding are circular shape. All things considered, the proposed sensor is remarkable to sense the concentration level of H2SO4 and solves real-world problems. [ABSTRACT FROM AUTHOR]

In this paper, a terahertz range hybrid structured with square hollow-core PCF-based edible oil sensor is presented and statistically examined. For the purpose of determining this proposed hollow core fiber's propagation characteristics, the finite element method is used with a circular perfectly matched layer boundary condition. In ideal geometrical circumstances, the recommended detector exhibits 98.45% relative sensitivity to various edible oils at optimum frequency of 1.8 THz. An extensive simulation of that microstructure fiber across THz frequency range reveals that it is possible to concurrently achieve very low effective material loss of 0.004632 cm−1 and a very low confinement loss of 1.07 × 10–15 dB/m. In addition, the proposed fiber is thoroughly studied for other crucial factors like total loss, spot size, and numerical aperture. This optical waveguide's outstanding achievements will make it possible to use it in a variety of practical terahertz applications. [ABSTRACT FROM AUTHOR]