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Multimodal retinal image registration
Štohanzlová, Petra ; CSc, Tomáš Suk, (referee) ; Harabiš, Vratislav (advisor)
This work deals with possibilities of registration of retinal images from different mo-dalities, concretely optical coherence tomography (OCT), scanning laser ophthalmoscopy (SLO) and fundus camera. In first stage is the interest focused on registration of SLO and fundus images, which will serve to determine area of interest for consecutive registration of OCT data. The final stage is finding correct location of OCT B-scans in fundus image. On the basis of the studied methods of registration was chosen method making use of computation of correlation coefficient for both cases. For finding optimal parameters of registration is used searching through whole space of parameters. In partial stages of the work was created algorithm for alignment of B-scans followed by detection of blood vessels and also simple algorithm for detection of blood vessels from fundus image. For more transparent registration the graphical user interface was created, which allows loading input images and displaying the result in several possible forms.
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Retinal image registration using phase correlation
Šikula, Viktor ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
This master thesis deals with retinal image registration using phase correlation technique. There are described properties of retinal images and modality of scanning. A geometrical transformation encompasing scale, rotation and translation between two retinal images is considered and the whole registration framework is described. There are used retinal images from fundus camera and scanning laser ophthalmoscope (SLO). In this thesis is described corresponding bifurcations detection using phase correlation and registration using second-order polynomial transformation. The results are subjectively and objectively verificated.
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Experimental data processing in real time
Veselý, Petr ; Harabiš, Vratislav (referee) ; Kolářová, Jana (advisor)
The thesis completes the current programming equipment for experimental measurement of isolated animal heart signals. It adds a block providing the pre-processing of the signals. The signals measured are the elektrogram (EG) and the action potential (AP). The origin of individual signals, the measuring method and the possibilities of noise elimination are dealt with in the theoretical part of the thesis. The practical part describes the pre-processing block securing the noise elimination during the AP. It uses accumulative methods of averaging the corresponding time periods of the AP. Based on the results of measuring the signal to noise ratio, the thesis suggests the most appropriate accumulative methods and their variables. In order for the chosen accumulative methods to work well, it is important to divide the AP process into sectors of corresponding shape (repeats). The connection between the EG and AP processes is used to determine the beginning and end of the sectors. These points are identified by the detection of R and T wave peaks in the EG. To detect the R and T waves, the thesis uses methods based on wavelet transform. The efficiency and accuracy of detection methods is verified by test EG signals with hand-marked R and T wave peaks.
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Wireless Nurse Care Calling
Bubník, Karel ; Sekora, Jiří (referee) ; Harabiš, Vratislav (advisor)
This work describes the design, construction a performance of such a complete wireless pager suitable for health care centers, rest homes, home application, for example for calling an attendant. This appliance is designed to be easy to attendance. A wireless transceiver is simplified and is attended only by one button. A wireless receiver also doesn't require a complicated manipulation. The aim is to create pager, which will be an useful assistant thanks to its price and simple construction.
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Preprocessing of ophthalmology images for image registration
Orešanská, Hana ; Sekora, Jiří (referee) ; Harabiš, Vratislav (advisor)
The aim of my thesis was research of the ophthalmology images processing. These methods contains image filtration, detection of important points in the image and registration. Image adjustment and the follow up registration is very important to find some deseases (e.g. glaucoma, where is a change of nervous threads going from retina ). For the image changes and registrations was made computer programme (Matlab, Graphical User Interface), where the user can try the different methods decribed in teoretical part of thesis.
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ECG signal classification
Smělý, Tomáš ; Harabiš, Vratislav (referee) ; Hrubeš, Jan (advisor)
This thesis deals with classification of different types of time courses of ECG signals. Main objective was to recognize the normal cycles and several forms of arrhythmia and to classify the exact types of them. Classification has been done with usage of algorithms of Neural Networks in Matlab program, with its add-on (Neural Network Toolbox). The result of this thesis is application, which makes possible to load an ECG signal, pre-process it and classify its each cycle into five classes. Percentage results of this classification are in the conclusion of this thesis.
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Optical disc detection in ophthalmologic images
Melša, Ondřej ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
This work is target on the detection of center and border of optical disk in AF (autofluorescent) and IR (infrared) images. The image are primarily modified at brightness area. The center of optical disk are sought after by algorithms, which offers program Matlab. As well are search border of optical disk. Results are comparison with engaged results and then is calculated effectivity of created algorithm.
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Registration of the autofluorescence images
Říha, František ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
The autofluorescence images of the retina, which are obtained by laser scanning confocal ophthalmoscope Heidelberg Retina Angiograph (HRA), are used for early glaucoma diagnosis. Glaucoma is caused by gradual damage of the optic nerves, which leads to the failing of eyesight and can even cause its complete loss. HRA system is used to obtain a set of retinal images, where every image represents certain segment of retina. This thesis describes image registration methods for retinal image mosaicing. The tested registration methods are based on the global function of similarity or the landmarks detection. As landmarks, the blood vessel bifurcations are considered.
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Application of neural networks for classification of T-wave alternations
Procházka, Tomáš ; Harabiš, Vratislav (referee) ; Hrubeš, Jan (advisor)
This thesis deals with analysis of T-wave Alternans (TWA), periodical changes of T wave in ECG signal. Presence of these alternans may predict higher risk of sudden cardiac death. From the several possible ways of TWA classification, the training algorithms of self organizing maps are used in this thesis. Result of the thesis is a program, which in the first step detects QRS complexes in the signal. Then, in the next step, gained reference points are used for T-waves detection. Detected waves are represented by a vector of significant points, which is used as an input for artificial neural network. Final output of the program is a decision about presence of TWA in the signal and its rate.
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Detection of the nerve fibres in ophthalmologic images
Urbánek, Dušan ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
This thesis deals with detection of the retinal nerve fiber layer in gray level retinal images taken by fundus camera. The first part describes a physiology of human eye and glaucoma disease. Then, the use of wavelet transform and algorithm of texture analysis applied for texture analysis. Next chapters describe theory of texture analysis named „Gray level run length matrices“ and its application for detection of the nerve fiber layer. Applications of this method are described for three types of retinal tissues and for whole image. The last chapter describes gray levels around optic disc and results obtained from parameters from GLRL matrices.
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