Wyniki 1-10 spośród 12 dla zapytania: authorDesc:"Przemysław ADAMKIEWICZ"

Implementation Image Analysis and Optimization Techniques in e-Medicus System DOI:10.15199/48.2018.01.24

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In this paper. gradient reconstruction algorithms, medical and stereoscopic images in e-Medicus system were implemented. The reconstruction problem is a nonlinear and ill-posed, whose solution calls for special regularized algorithms [6-8]. In many cases the linear systems arising in practice consist of real number coefficients and data. The image reconstruction is very sensitive to the ubiquitous modelling errors which are caused by inaccurately known auxiliary variables of the measurement model [21-25]. Figure 1 presents the model of the imaging system. Fig. 1. The model of the imaging system The image data is of immense practical importance in medical informatics. Medical images, such as Computed Axial Tomography (CAT), Magnetic Resonance Imaging (MRI), Ultrasound, and X-Ray, in standard DICOM formats are often stored in Picture Archiving and Communication Systems (PACS) and linked with other clinical information in EHR clinical management systems. Research efforts have been devoted to processing and analysing medical images to extract meaningful information such as volume, shape, motion of organs, to detect abnormalities, and to quantify changes in follow-up studies. Recent advances in a wide range of medical imaging technologies have revolutionized how we view functional and pathological events in the body and define anatomical structures in which these events take place. X-ray, CAT, MRI, Ultrasound, nuclear medicine, among other medical imaging technologies, enable 2D or tomographic 3D images to capture in-vivo structural and functional information inside the body for diagnosis, prognosis, treatment planning and other purposes. Stereoscopic images Stereoscopic imaging techniques allow for 3D images. Simultaneous recording of two images allows for the mutual dependence of the spatial object, the distance from the observer and the depth of the scene. In order to obtain stereosc[...]

Effective algorithm for tomography imaging in threedimensional problems DOI:10.15199/48.2019.03.27

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There are many different methods to optimize the imaging problem solution [1-11]. Let us consider an Ultrasonic wave for which we can assume propagation along straight lines. Using this feature, an effective modification of an important part of image reconstruction algorithm (called Algebraic Reconstruction Techniques - ART), invented in 1938 by S. Kaczmarz, has been proposed in this paper. The essence of proposed algorithm modification in 3D space is an approximation of the voxel, so far treated as cube, by a sphere inscribed in this cube. The attempt of using sphere-shaped voxels instead of cubic voxels could be questionable. In case of cubes the whole object volume can be covered because any wall of one cubic cling to another wall of the neighbouring cube. In case of sphere, it touches another sphere only in one point. So, between spheres there exists volume of object outside spheres which is not contained in voxels. The authors refer to this issue later in this paper (for example Fig. 6 and Fig. 7) showing that it has no significant influence on imaging. This modification is one more simplifying assumption for that kind of imaging. That is why the main goal of this paper is to prove effectiveness of such an approach by numerical experiment. What is more, such modification allows to significantly accelerate the method for determining voxels, through which the ray passes in the considered region. In such a way we have got much faster imaging software, which is particular important in cases where "on line" imaging is needed. Time profit is particularly high for 3D problems [12- 18]. Tomographic images construction in 3D space In the case of the modelling area in 3D space, you must make its discretization on a cube voxel, in which the points common for rays and voxel walls should be determined (see for example Fig. 1). Such calculations are pretty complicated. Ray passing through the voxel perforate two of six walls. Th[...]

ECT Measurement System with Optical Detection for Quality Control of Flow Process DOI:10.15199/48.2016.12.40

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Multi-phase flow measurement technologies are still built and improved. There is a clear trend in the industry to implement more optimum related functions, where the focus is put on an active control and the monitoring system. Control related active optimum functions can only be realised with a system that allows the electronic control. Electrical capacitance tomography (ECT) is a method of imaging cross-sections of vessels and pipelines containing dielectric material. Permittivity distribution is determined with a multi-electrode sensor and interpreted by software. This paper provides description of the device as well as results of exemplary measurements. Streszczenie. Technologie pomiarowe przepływu wielofazowego są wciąż budowane i ulepszane. Istnieje wyraźna tendencja w przemyśle do realizacji funkcji związanych z bardziej optymalnym sterowaniem, w którym nacisk kładziony jest na aktywną kontrolę i system monitoringu. Optymalizacja funkcji do aktywnej kontroli może być realizowana tylko w systemie, który umożliwia sterowanie elektroniczne. Elektryczna tomografia pojemnościowa (ETP) jest metodą obrazowania przekrojów naczyń i rurociągów zawierających materiał dielektryczny. Przenikalność elektryczna jest wyznaczana za pomocą czujnika wieloelektrodowego i interpretowana przez oprogramowanie. Niniejszy dokument zawiera opis urządzenia, jak również przykładowe wyniki pomiarów.(System pomiaru ETP z optyczna detekcją do kontroli jakości procesów przepływu). Keywords: Electrical Capacitance Tomography, Image Analysis, Sensors Słowa kluczowe: elektryczna tomografia pojemnościowa, analiza obrazów, sensory Introduction Simple and low cost intrusive probes have been used in many operation systems to obtain flow information. Process tomography becomes even more appealing when nonintrusive sensors are used to obtain the cross-sectional images. Designed control system allows for correlative studies using sets of measuring electrodes (Fig. 1). The [...]

Electrical Capacitance Tomography and Optical Detection in Quality Control System DOI:10.15199/48.2017.12.53

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Modern production processes are increasingly complex, while customers are demanding higher quality products at the lowest price. This situation increases the importance of process optimization. Products and requirements are changing faster and faster, technologists have less and less time to learn the process and to optimize it solely on the basis of their own experience. On the other hand, very often the processes are automated and metered in detail, so we have plenty of data describing it. Analysis of the data may be used for process optimization in different ways and it can affect many aspects of process management. We can detect disturbances in the process, find the causes affecting the problems with quality, and choose the optimal settings for the process, comparing different preparation procedures and many others. It is worth noting that in the processes, there are many people involved in with different tasks and permissions. Therefore, data analysis tool should provide access control. The research project assumes creation of two measurement platforms: a set of multiphase flow system and a mini production line. In the first case we will be analysing two-phase flows of liquid (water) and air. That type of flow is commonly used in chemical reactors where air is mixing substances [4,9,10]. Electrical Capacitance Tomography Electrical capacitance tomographs are devices capable of performing analysis of pipeline fragment or a vessel filled with examined medium [15]. Obtained cross-section’s image reconstruction can be analysed further for an automated quality control system’s autonomous and correct decision. However, existing industrial solutions are still of significant size and structurally complex [2,4,5]. This fact greatly limits the number of actual deployments. Decision makers are afraid of electrical capacitance tomography (ECT) implementation due to high costs of possible equipment failures and because[...]

Moisture Wall Inspection Using Electrical Tomography Measurements DOI:10.15199/48.2018.01.25

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One of the major causes of pathologies in historic buildings all over the world is the presence of moisture, particularly rising damp. Moisture transfer in walls of an old buildings, which are in direct contact with the soil, leads to a migration of soluble salts responsible for many building problems. Building porous materials (e.g. brick or concrete), both natural and manufactured have pores (like a sponge) and the moisture can be pulled up against gravity (capillary effect). Rising damp from the soil is a problem in old buildings, especially without adequate horizontal and vertical insulation of foundations. Moisture creates a danger not only to the walls, but also to human health. It promotes progress of rheumatic disorders and formation of fungus on the walls. Fungus can cause allergies and many other diseases. There are many different drainage systems (dry as watertight barriers, injection of hydrofuge products, etc.). Regardless of the method it is very important to continuously monitor the status of damp during the drying process [5]. The models of a brick wall are presented in Fig. 1. The test results obtained by the non-destructive impedance tomography are compared with the results obtained by numerical simulations. There were prepared two prototype measuring systems (16 and 32 electrodes). First of them is a system contains the 16 electrodes for measuring damp brick wall on one side (Fig. 1a). Second one is a system with 32 electrodes for test on both sides of wall (Fig. 1b). Measurement systems The electrical tomography (ET) is a technique of imaging the [...]

Efektywny algorytm obrazowania w tomografii ultradźwiękowej i radiowej dla zagadnień dwuwymiarowych DOI:10.15199/48.2018.06.11

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W ostatnich latach obserwujemy dynamiczny rozwój Tomografii niekonwencjonalnej jak na przykład dyfuzyjnej tomografii optycznej [12,13,16]. Przez tomografię konwencjonalną, autorzy rozumieją tomografię o ustalonym zasięgu zastosowań w medycynie czy też przemyśle, jak na przykład tomografię rentgenowską, tomografię rezonansu magnetycznego czy tomografię ultradźwiękową nazywaną powszechnie USG. Ta ostatnia coraz śmielej stosowana jest w przemyśle [4,10]. Również tomografia fal z radiowego zakresu jest ostatnio coraz chętniej stosowana [2,3,9,17]. Transmisyjną tomografię ultradźwiękową i radiową tomografię łączy jedna wspólna cecha. Fale ultradźwiękowe i radiowe, rozchodzą się po liniach prostych. Wykorzystując tę cechę, zaproponowano efektywną modyfikację istotnego fragmentu dobrze znanego w literaturze algorytmu algebraicznej rekonstrukcji obrazu (ang. Algebraic Reconstruction Techniques (ART)), zaproponowanego po raz pierwszy przez S. Kaczmarza [5,6,7,15]. Istota tej modyfikacji polega na przybliżeniu kształtu piksela, (który do tej pory traktowany był jako kwadratowa komórka), do kształtu kołowego. Zmiana ta pozwala w sposób istotny przyspieszyć metodę wyznaczania pikseli, przez które przechodzi dany promień w rozpatrywanym obszarze. Dzięki temu w zagadnieniach 2D uzyskujemy znaczne przyspieszenie obrazowania, co ma szczególne znaczenie w przypadkach, kiedy zależy nam na obrazowaniu "on line". Zysk czasowy będzie jeszcze większy dla zagadnień 3D, ale będzie to przedmiotem osobnego artykułu. Metody algebraiczne obrazowania tomograficznego Większość algorytmów z grupy algebraicznych technik rekonstrukcyjnych - ART bazuje na metodologii aproksymacji funkcji przez szeregi o skończonej długości [6,15]. W metodach tych dokonuje się uproszczenia polegającego na przyjęciu, że rekonstruowany obraz składa się ze skończonej liczby elementów. Obraz odtwarzany jest za pomocą algorytmu dyskretyzującego badany obszar do postaci n kwa[...]

Implementation of the LARS method to solve the inverse problem in electrical tomography DOI:10.15199/48.2018.12.31

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The tomographic method makes it possible to obtain moisture distribution inside the wall in a digital form. This is extremely useful when you need to obtain a high quality image in a non-invasive way. Visualization of the moisture inside the wall enables the implementation of effective protection of walls against moisture and in the case of old buildings - effective and fast drainage of walls. This is of particular importance for thick walls. The most important advantages of the proposed measurement system include non-invasive and non-destructive measurement of the tested object thanks to specially designed surface electrodes and the ability to display the moisture distribution inside the wall both on the plane (2D) and spatially (3D). Due to the fact that wall conductivity depends mainly on the degree of humidity, it is possible to determine the distribution of moisture inside the wall using the indirect method - based on the conductivity map. In the case of brick walls, this is the only cheap and non-invasive method, unlike the weight method, in which the wall must be drilled, and the heat generated evaporates a certain amount of moisture. This is, therefore, an invasive method of quality, not a quantitative method, thus subject to an additional error. We are interested only in differential (relative) images, on which we can distinguish specific colors from a dry background. Thanks to this, moisture content can be assessed in the tested cross-sections of walls or bricks. There are many different methods to optimize the solution mentioned above. problem [8-14,22,23]. This article presents the method of using the smallest angle algorithm [4] to solve the inverse problem in electrical tomography for damp wall [1-3,5-7,15-21]. Statistical method Reduction of adverse effects of multi-polarization between predictors can be achieved by applying the lowest angle regression algorithm for this solution. The algorithm in question [...]

Application of Gaussian Kernel with Regard to Correlations for Image Reconstruction in Electrical Tomography DOI:10.15199/48.2019.05.14

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This article proposes a new solution based on the analysed methods that enable the proper reproduction of the image. This work gives promising results as a new horizon to solve practical problems. The Support Vector Machine for Regression with Gaussian kernel was implemented. A regression method gives more accurate and stable reconstruction results in solving the inverse problem in electrical tomography. There are many ways to solve the optimization problem [1-10]. The statistical methods [11] were used to reconstruct the image in electrical impedance tomography. The main objective of the tomography is to perform image reconstruction. During the measurements, we can see that the measured values from some electrodes are strongly correlated (due to the way of measurement). In this case, we have a multicollinearity problem. Electrical impedance tomography (EIT) is an ill-posed inverse problem. In the EIT, the electrical voltages are injected into the object using a set of electrodes attached to the object's surface, and the potentials are measured. The object's conductivity is reconstructed on the basis of known voltages and measured potentials. Reconstruction of electrical impedance tomography requires accurate modelling. EIT is a method of imaging in which the conductivity distribution of the tested object is estimated on the basis of measurements of electrical voltages and potentials of electrodes at the boundary. To obtain quantitative information on the change in conductivity, it would be better to use a non-linear model in the differential imaging solution [12-14]. In the case when the objects are different (in the sense of size), the grid is made, then the model parameters are estimated, and only in the final phase the reconstruction is a labour-intensive process. The approach used below is an attempt to create a model that would analyse similar objects of different sizes - we learn on a smaller object, but we recogn[...]

Detection of seepages in flood embankments using the ElasticNET method DOI:10.15199/48.2019.01.40

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Electric tomography is based on the transformation of data taken from the surface of the tested object into the image of its cross-section. There are many methods to optimize the obtained image by solving the appropriate objective function [1-5,13,15,16,20-25,32]. The algorithm based on the ElasticNET presented in this article is a new proposal in tomography. Fig. 1. Model of measuremnt system. The way of working of electrical impedance tomography (EIT) consists in introducing electrical voltage to the tested object by means of a set of electrodes located on the surface of the object. Next, the measured values of electrical potentials between individual electrode pairs are collected. Conductance of individual sections of the crosssection of the tested object is reconstructed on the basis of known values of voltages and measured values of potentials. Reconstruction of the image obtained by electrical tomography requires sophisticated modeling. This method of imaging consists in the fact that the conductivity distribution of the tested object is estimated on the basis of measurements of electrical voltages and electrode potentials on the surface of their contact with the tested object. In order to obtain quantitative data on changes in the conductivity inside an object, it is more effective to apply a non-linear model in differential imaging [1,6-12,14,17- 199,26-31]. In Fig. 1 shows the model of the measurement system. ElasticNET Let’s consider the problem of recognizing linear dependencies (1) Y  X   where Y Rn , X Rnk1 are the observation matrices of a output variable and predictive variables respectively,   Rk1means a matrix of structural parameters, while  Rn vector of independent random variables. The wellknown method of least squares consists in estimating unknown parameters &[...]

A hybrid tomography for assessing the moisture level of walls and building condition DOI:10.15199/48.2019.02.23

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The non-destructive method [4,20,26,27,34] of brick wall insulation is tested using electrical impedance tomography (EIT). The aim of the presented method is to obtain image reconstruction using the proposed solution. The set was used to determine the humidity of the test wall on specially constructed models. The presented algorithms have been successfully used in the reconstruction of model wall measurement data. These approaches were based on the sensitivity analysis. An effective algorithm for solving forward and inverse problems would also improve many numerical results of the proposed methods. In modeling the problem in electrical tomography, it is required to identify unknown conductivities from near-limit potential measurements [17-19,21]. The discussed technique can be used to solve inverse problems in electrical impedance tomography. Fig. 1. Hybrid tomography system. Electrical tomography consists in restoring the conductivity of the interior of the tested object with the knowledge of currents and tensions imposed on its surface. Most of the available research methods allow only a point evaluation of moisture, thanks to which it is possible to achieve only the discrete distribution itself. Permeation of moisture in the walls of old buildings, which are in direct contact with the soil, leads to migration of soluble salts in relation to many wall problems. Building porous materials (eg bricks or concrete), both natural and made, has pores (like a sponge). The data collection system collects the measured voltage from the electrode and then processes the data [1-3,5-11,13-15,28-33]. Figure 1 presents the model of a hybrid tomography system. Measurement system The electrical tomography is a technique of i[...]

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