5 research outputs found

    Segmentation Model for Automatic Analysis of Periosteal Callus Dynamic Analysis from X-ray Images

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    Cílem této diplomové práce je návrh segmentačního modelu periostálního svalku s následnou analýzou geometrických parametrů a dynamiky hustoty v průběhu léčby zlomeniny. V práci byly použity snímky fraktur kostí z RTG obrazu. Analýza byla zhotovena pomocí variabilních kostí, a to kostí stehenní, klíční a bérce. Celý proces segmentace byl aplikován v prostředí MATLAB. Algoritmus se skládá z postupu, který obsahuje určení oblasti zájmu, úpravu kontrastu a jasu, filtraci obrazu, Fuzzy C means, aktivní kontury a morfologické operace. Nejpřesnějších výsledků segmentace dosahuje periostální svalek tvořen na kosti stehenní. Vzhledem k různosti tvorby a velikosti periostálního svalku během hojení kosti, je potřeba nastavení segmentace pro přesnější výsledky konkretizovat. Hodnocení vývoje periostálního svalku v průběhu léčby proběhlo pomocí ukazatelů geometrických parametrů a dynamiky hustoty, která byla reprezentována jasovým spektrem obrazu. Geometrické parametry poukazují na vývoj periostálního svalku v čase. Analýza výsledků dynamiky hustoty odpovídá zvyšování hustoty svalku v průběhu pozorování léčby zlomeniny. Analýza vykazuje ztotožnění hustoty periostálního svalku vzhledem ke zdravé kosti v čase léčby.The aim of this diploma thesis is to design a segmental model of the periosteal callus with subsequent analysis of geometric parameters and density dynamics during fracture treatment. X-ray images of bone fractures were used in this work. The analysis was performed using variable bones, namely the femur, clavicle and lower leg bones (tibia and fibula). The whole segmentation process was applied in the MATLAB environment. The algorithm consists of a procedure that includes region of interest determination, contrast and brightness adjustment, image filtering, Fuzzy C means, active contours, and morphological operations. The most accurate segmentation results occured on a periosteal muscle formed on the femur. Due to the diversity of periosteal muscle formation and size during bone healing, it is necessary to specify the segmentation settings for more accurate results. The development of the periosteal muscle during the treatment was performed using indicators of geometric parameters and density dynamics, which were represented by the brightness spectrum of the image. Geometric parameters show the development of the periosteal muscle over time. The analysis of the results of the density dynamics shows an increase in the density of the muscle during the observation of the fracture treatment. The analysis shows an identification of periosteal muscle density relative to healthy bone at the time of treatment.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn

    PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

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    The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery

    Progressive changes in the properties of bone during soft tissue decomposition

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    Changes in bone characteristics during soft tissue putrefaction were investigated over 140 days, equating to between 638 and 1450 cumulative cooling degree days (CCDD) depending on ambient temperature using a porcine experimental model in surface and burial depositions. The hypothesis that changes observed in bone characteristics during soft tissue putrefaction could be utilised for possible forensic applications was proved. Human bones were tested for comparison. The techniques used were colorimetric analysis of staining, measurement of micro-crack lengths (in the order of 0.1 to 1.0 mm) on fractured bone surfaces under scanning electron microscopy, inductively coupled plasma optical emission spectroscopy elemental profiling, thermogravimetric analysis (TGA), zoological mass spectrometry profiling non-collagenous peptide content, and Vickers hardness testing. The findings pertaining to the experimental porcine bone samples were as follows. Stain colour did not equalise between periosteal and fractured cortical bone surfaces. The fracture is widely considered perimortem if said surfaces are homogeneous in colour and postmortem if different. Observed inconsistences in colour change limit the potential of this technique as a potential forensic test of postmortem interval (PMI). After 28 CCDD, shorter intersecting micro-cracks changed to longer linear micro-cracks tracking lamellae. A longitudinal to tangential Vickers hardness (HV) ratio of 1.5 to 1 associated with minimal decomposition indicated 250 CCDD or less elapsed. The same ratio associated with marked decomposition indicated 1450 CCDD or more elapsed. A ratio of less than 1:1 indicated 250 to 1450 CCDD. Decreases in iron, sodium and potassium concentrations associated with tissue fluids can determine if bone is in the early stages of decomposition. TGA correlation of water loss between 22 and 100˚C with observed changes in micro-crack lengths, HV, and elemental profiles suggested progressive dehydration as the underlying common factor. These techniques demonstrated some potential to be developed as forensic tests of PMI. As no correlation with PMI was evident with proteomic profiling of non-collagenous peptides, no such potential was demonstrated
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