Contribution of statistical methods to the study of worn paint coatings surface topography

A surface morphology can be described by numerous roughness parameters. Making the most of the power of modern computers, the relative relevance of a hundred surface roughness parameters is assessed in this investigation with regard to the relationships between the morphological texture, the low wear damage and the gloss of polymer coatings. The relevance of each roughness parameter is quantitatively determined by statistical indexes of performance defined and calculated by combining the two-way ANalysis Of VAriance (ANOVA) and the Computer Based Bootstrap Method (CBBM). The fractal dimension is shown to be the most relevant parameter for characterising the different morphological textures of studied coatings and the average curvature radius of peaks for characterising the effect of wear. A linear relationship is found between the reduction of gloss and the reduction of the average curvature radius of peaks due to wear. Besides, it is also shown that angles of 85° and 20° are the most relevant for characterising, respectively, the effects of the morphological texture of polymer coatings and wear on the gloss measurements

Secure and Privacy-Preserving Automated Machine Learning Operations into End-to-End Integrated IoT-Edge-Artificial Intelligence-Blockchain Monitoring System for Diabetes Mellitus Prediction

Diabetes Mellitus, one of the leading causes of death worldwide, has no cure to date and can lead to severe health complications, such as retinopathy, limb amputation, cardiovascular diseases, and neuronal disease, if left untreated. Consequently, it becomes crucial to take precautionary measures to avoid/predict the occurrence of diabetes. Machine learning approaches have been proposed and evaluated in the literature for diabetes prediction. This paper proposes an IoT-edge-Artificial Intelligence (AI)-blockchain system for diabetes prediction based on risk factors. The proposed system is underpinned by the blockchain to obtain a cohesive view of the risk factors data from patients across different hospitals and to ensure security and privacy of the user's data. Furthermore, we provide a comparative analysis of different medical sensors, devices, and methods to measure and collect the risk factors values in the system. Numerical experiments and comparative analysis were carried out between our proposed system, using the most accurate random forest (RF) model, and the two most used state-of-the-art machine learning approaches, Logistic Regression (LR) and Support Vector Machine (SVM), using three real-life diabetes datasets. The results show that the proposed system using RF predicts diabetes with 4.57% more accuracy on average compared to LR and SVM, with 2.87 times more execution time. Data balancing without feature selection does not show significant improvement. The performance is improved by 1.14% and 0.02% after feature selection for PIMA Indian and Sylhet datasets respectively, while it reduces by 0.89% for MIMIC III

Influence of the morphological texture on the low wear damage of paint coated sheets

The influence of the morphological texture (flat and structured) of a polyester based paint coating on the low wear damage is characterised by means of roughness and gloss measurements. Using statistical methods, the aim of the investigation is to determine, among about 60 surface roughness parameters, the most relevant of them with regard to the morphological texture and the wear behaviour of polymer coatings. The level of relevance of each roughness is quantitatively assessed through the calculation of a statistical index of performance determined by combining the two-way analysis of variance (ANOVA) and the computer based Bootstrap method (CBBM). For the experimental conditions related to the present investigation, the fractal dimension and a roughness parameter directly related to the number of inflexion points of the profiles are shown to be the most relevant parameters for discriminating the different morphological textures of studied coatings and for characterising the low wear damage, respectively. Even if the gloss reduction related to the low wear damage is more visually perceptible at a macroscopic scale for the flat products than for the structured ones, the magnitude of this damage is shown to be however very similar at a microscopic scale whatever the morphological texture of the paint coatings

Common Features on Damage Mechanisms Identified on Various Metal and Ceramic on Polyethylene Articulating Surfaces of Total Hip Prostheses

This paper presents a methodology for assessing the in-vivo degradation mechanisms of articular components of total hip replacement (THR) prostheses of Charnley type. The experimental procedure revealed that common features can be observed even if the clinical cases under investigation were quite different with regard to the demographic data. It particularly emphasises the detrimental effects of foreign bodies on the damage of the articulating surfaces. These foreign bodies can migrate into the joint space before embedding definitely into the Ultra High Molecular Weight Polyethylene (UHMWPE) acetabular cup surface where they further participate to a third body wear mechanism accelerated by a progressive increase of the femoral head roughness. Our experimental results underline, from a practical point of view, the need for careful manufacturing and clinical handling of porous surfaces, advocate for a systematic assessment of retrieved components, particularly when changed because of unexplained wear, and make questionable the clinical use of multifilament trochanteric cables

Contribution of statistical methods to the study of worn paint coatings surface topography

A surface morphology can be described by numerous roughness parameters. Making the most of the power of modern computers, the relative relevance of a hundred surface roughness parameters is assessed in this investigation with regard to the relationships between the morphological texture, the low wear damage and the gloss of polymer coatings. The relevance of each roughness parameter is quantitatively determined by statistical indexes of performance defined and calculated by combining the two-way ANalysis Of VAriance (ANOVA) and the Computer Based Bootstrap Method (CBBM). The fractal dimension is shown to be the most relevant parameter for characterising the different morphological textures of studied coatings and the average curvature radius of peaks for characterising the effect of wear. A linear relationship is found between the reduction of gloss and the reduction of the average curvature radius of peaks due to wear. Besides, it is also shown that angles of 85° and 20° are the most relevant for characterising, respectively, the effects of the morphological texture of polymer coatings and wear on the gloss measurements

Nouvelle méthode d’évaluation du taux de pénétration linéaire et du volume d'usure d'explants en polyethilène

Il est reconnu que l’usure des composants articulaires de prothèses totales de hanche (PTH) est un des principaux facteurs à l’origine de la limitation de la durée de vie de ces dispositifs médicaux. En pratique, les chirurgiens estiment cette usure en effectuant une mesure du taux de pénétration linéaire sur des clichés radiographiques lors du suivi médical des patients. Cette mesure est ensuite utilisée pour faire un calcul de volume d’usure à partir d’une équation analytique relative à un modèle. L’objectif de notre étude est de présenter une nouvelle méthode d’évaluation du taux de pénétration linéaire et du volume d’usure à partir de l’analyse in vitro d’explants en polyéthylène. Ne faisant appel à aucun modèle analytique, notre méthode s’appuie sur le traitement de mesures d’explants sur Machine à Mesurer Tridimensionnelle. La pertinence de notre méthode est validée par simulation

Nouvelle méthode d’évaluation du taux de pénétration linéaire et du volume d'usure d'explants en polyethilène

Il est reconnu que l’usure des composants articulaires de prothèses totales de hanche (PTH) est un des principaux facteurs à l’origine de la limitation de la durée de vie de ces dispositifs médicaux. En pratique, les chirurgiens estiment cette usure en effectuant une mesure du taux de pénétration linéaire sur des clichés radiographiques lors du suivi médical des patients. Cette mesure est ensuite utilisée pour faire un calcul de volume d’usure à partir d’une équation analytique relative à un modèle. L’objectif de notre étude est de présenter une nouvelle méthode d’évaluation du taux de pénétration linéaire et du volume d’usure à partir de l’analyse in vitro d’explants en polyéthylène. Ne faisant appel à aucun modèle analytique, notre méthode s’appuie sur le traitement de mesures d’explants sur Machine à Mesurer Tridimensionnelle. La pertinence de notre méthode est validée par simulation

Influence of the morphological texture on the low wear damage of paint coated sheets

International audienceThe influence of the morphological texture (flat and structured) of a polyester based paint coating on the low wear damage is characterised by means of roughness and gloss measurements. Using statistical methods, the aim of the investigation is to determine, among about 60 surface roughness parameters, the most relevant of them with regard to the morphological texture and the wear behaviour of polymer coatings. The level of relevance of each roughness is quantitatively assessed through the calculation of a statistical index of performance determined by combining the two-way analysis of variance (ANOVA) and the computer based Bootstrap method (CBBM).For the experimental conditions related to the present investigation, the fractal dimension and a roughness parameter directly related to the number of inflexion points of the profiles are shown to be the most relevant parameters for discriminating the different morphological textures of studied coatings and for characterising the low wear damage, respectively. Even if the gloss reduction related to the low wear damage is more visually perceptible at a macroscopic scale for the flat products than for the structured ones, the magnitude of this damage is shown to be however very similar at a microscopic scale whatever the morphological texture of the paint coatings

Common Features on Damage Mechanisms Identified on Various Metal and Ceramic on Polyethylene Articulating Surfaces of Total Hip Prostheses

This paper presents a methodology for assessing the in-vivo degradation mechanisms of articular components of total hip replacement (THR) prostheses of Charnley type. The experimental procedure revealed that common features can be observed even if the clinical cases under investigation were quite different with regard to the demographic data. It particularly emphasises the detrimental effects of foreign bodies on the damage of the articulating surfaces. These foreign bodies can migrate into the joint space before embedding definitely into the Ultra High Molecular Weight Polyethylene (UHMWPE) acetabular cup surface where they further participate to a third body wear mechanism accelerated by a progressive increase of the femoral head roughness. Our experimental results underline, from a practical point of view, the need for careful manufacturing and clinical handling of porous surfaces, advocate for a systematic assessment of retrieved components, particularly when changed because of unexplained wear, and make questionable the clinical use of multifilament trochanteric cables

Nouvelle méthode d’évaluation du taux de pénétration linéaire et du volume d'usure d'explants en polyethylène

National audienceIl est reconnu que l’usure des composants articulaires de prothèses totales de hanche (PTH) est un des principaux facteurs à l’origine de la limitation de la durée de vie de ces dispositifs médicaux. En pratique, les chirurgiens estiment cette usure en effectuant une mesure du taux de pénétration linéaire sur des clichés radiographiques lors du suivi médical des patients. Cette mesure est ensuite utilisée pour faire un calcul de volume d’usure à partir d’une équation analytique relative à un modèle. L’objectif de notre étude est de présenter une nouvelle méthode d’évaluation du taux de pénétration linéaire et du volume d’usure à partir de l’analyse in vitro d’explants en polyéthylène. Ne faisant appel à aucun modèle analytique, notre méthode s’appuie sur le traitement de mesures d’explants sur Machine à Mesurer Tridimensionnelle. La pertinence de notre méthode est validée par simulation