Predictive model of biliocystic communication in liver hydatid cysts using classification and regression tree analysis

<p>Abstract</p> <p>Background</p> <p>Incidence of liver hydatid cyst (LHC) rupture ranged 15%-40% of all cases and most of them concern the bile duct tree. Patients with biliocystic communication (BCC) had specific clinic and therapeutic aspect. The purpose of this study was to determine witch patients with LHC may develop BCC using classification and regression tree (CART) analysis</p> <p>Methods</p> <p>A retrospective study of 672 patients with liver hydatid cyst treated at the surgery department "A" at Ibn Sina University Hospital, Rabat Morocco. Four-teen risk factors for BCC occurrence were entered into CART analysis to build an algorithm that can predict at the best way the occurrence of BCC.</p> <p>Results</p> <p><b>I</b>ncidence of BCC was 24.5%. Subgroups with high risk were patients with jaundice and thick pericyst risk at 73.2% and patients with thick pericyst, with no jaundice 36.5 years and younger with no past history of LHC risk at 40.5%. Our developed CART model has sensitivity at 39.6%, specificity at 93.3%, positive predictive value at 65.6%, a negative predictive value at 82.6% and accuracy of good classification at 80.1%. Discriminating ability of the model was good 82%.</p> <p>Conclusion</p> <p>we developed a simple classification tool to identify LHC patients with high risk BCC during a routine clinic visit (only on clinical history and examination followed by an ultrasonography). Predictive factors were based on pericyst aspect, jaundice, age, past history of liver hydatidosis and morphological Gharbi cyst aspect. We think that this classification can be useful with efficacy to direct patients at appropriated medical struct's.</p

Binary feature descriptor for omnidirectional images processing

International audienceAn omnidirectional image has a 360? view around a viewpoint and which could be applied in a variety of fields, such as autonomous navigation, surveillance systems, virtual reality and remote monitoring, is presented. Many techniques of digital image processing rely on local descriptors to characterize the scene information around interest points (or keypoints) in the omnidirectional images. Despite the fact that a lot of advancements have been made in the area of keypoint descriptors over the last years, the literature on omnidirectional image processing for the most part still focuses on float-point descriptors, such as SIFT and SURF, and largely neglects more recent descriptors, such as the BRISK descriptor. In this paper we try to bridge this gap and assess the usefulness of the BRISK descriptor for the task of omnidirectional images processing. This work is a direct comparison of the BRISK and SURF descriptors within a simple verification framework, in order to see the improvement that can be achieved. Our results indicate that the BRISK descriptor is a viable alternative to the SURF descriptor for omnidirectional images processing and due to its binary nature is particularly useful for real-time localization techniques and autonomus navigation which has the visual sensor, including omnidirectional camera

Synthesis and characterization of Mg-Fe layer double hydroxides and its application on adsorption of Orange G from aqueous solution

International audienceLayered double hydroxide (LDH) with hydrotalcite-like structure containing Mg(II) and Fe(III) in the layers and its calcined form were prepared at different Mg/Fe molar ration by co-precipitation method at fixed pH= 10 and followed by calcination at 500 ◦C (denoted CLDH). The obtained materials were characterized by powder X-ray diffraction (PXRD), FT-IR spectroscopy, and TGA. The prepared LDH and CLDH were used for Orange G (Acid Orange 10) dye removal from aqueous solutions. Batch studies were carried out to address various experimental parameters such as contact time, pH, sorbent dose and temperature. The sorption kinetics data fitted the pseudo-second order model. The isotherms were established and the parameters calculated. The sorption data fitted the Langmuir model with good values of the correlation coefficient. The sorption capacity of CLDH was found to be almost independent on initial pH of solution in the range 3-13 and approximately 5 times higher than that of LDH

Visual Servoing

International audienceVisual servoing refers to the use of visual data as input of real-time closed-loop control schemes for controlling the motion of a dynamic system, a robot typically. It can be defined as sensor-based control from a vision sensor and relies on techniques from image processing, computer vision, and control theory

Robot Visual Control

International audienc