|
|
Device for simultaneous acquisition of PCG and PPG signals
Matoušek, Denis ; Králík, Martin (referee) ; Mézl, Martin (advisor)
This bachelor's thesis deals with the design and implementation of equipment for phonocardiographic and photoplethysmographic measurements. The theoretical part discusses the description of the origin of heart sounds, the place and method of measurement in the framework of phonocardiography. The practical part describes several options for building individual devices with the help of a Raspberry Pi 4 or with the help of measuring technology and a non-soldering field. Subsequently, the best solutions for PPG and PCG data acquisition are selected. 10 volunteers were measured on the final device. The scanned data is processed in the Python environment. Individual measurement results are described, documented, compared, and evaluated against other measurements.
|
|
|
Pharmacokinetic modelling in Positron Emission Tomography
Čaňková, Lenka ; Jiřík, Radovan (referee) ; Mézl, Martin (advisor)
This bachelor thesis deals with pharmacokinetic compartmental modelling in positron emission tomography. It includes a description of the basic pharmacokinetic variables and models. Models for selected radiopharmaceuticals are theoretically developed. Simulations of different organs in the Simulink environment have been performed for the radiopharmaceutical 18F-FDG. A brain slice model for the radiopharmaceutical [11C]-PS13 was created. Estimation of constants and optimization of models based on real data was performed. Subsequently, graphs of radiopharmaceutical concentrations as a function of time were plotted and described.
|
|
|
Photoreceptor detection methods in high-resolution retinal images
Vicianová, Jana ; Mézl, Martin (referee) ; Odstrčilík, Jan (advisor)
This thesis deals with the detection of photoreceptors in images captured by a camera using adaptive optics. The theoretical part of the work describes the anatomy and physiology of the eye, the retina and the diseases affecting it. Subsequently, current approaches in the field of photoreceptor detection are described. Selected methods are implemented in the practical part of the work. Modifying them, a photoreceptor detector is created. The results of individual methods are evaluated and compared.
|
|
|
Spatial-temporal epidemiologic models of Covid-19
Schubert, Richard ; Ředina, Richard (referee) ; Mézl, Martin (advisor)
This work aims to establish a fundamental framework for studying spatially diffusive models that describe the dynamics of infectious disease spread with constant parameters in a homogeneous domain. Initially, compartmental models and their extension to spatial domains are examined, followed by the theory of metapopulation models, where the degree of coupling between populations and the overall reproductive number R0 is discussed. Furthermore, the relationship between R0 and the shape of the spatial distribution of infected individuals in a simple diffusive SIR model is modeled. The influence of Neumann boundary conditions versus Dirichlet boundary conditions on R0 is demonstrated. In the second part of the work, selected findings and conclusions of studies that applied models in the spatiotemporal domain to analyze and predict the COVID-19 pandemic are summarized. In the third part of the work, a model with diffusive and metapopulation elements is fitted to epidemiological data from Lombardy in 2020, and the suitability of this approach is discussed.
|
|
| |
|
|
Prediction of radiotherapy response in rectal cancer by MR
Chmela, Radek ; Nohel, Michal (referee) ; Mézl, Martin (advisor)
This diploma thesis deals with the issue of predicting the response of rectal cancer to radiotherapy. The work is divided into four chapters. In the first two, the anatomy of the rectum, types of cancer and individual diagnostic methods are described, together with algorithms for detecting objects in images. In the third chapter, there is a description of the solution for automatic segmentation and prediction of the effectiveness of radiotherapy. In the fourth chapter, the achieved results are discussed.
|
|
|
Simulation of Perfusometric Data
Hývlová, Denisa ; Mézl, Martin (referee) ; Jiřík, Radovan (advisor)
This diploma thesis focused on the simulation of perfusion MRI data. The introduction describes standard perfusion imaging methods, DCE and DSC, and the quantitative analysis of perfusion. In the following section, simulation of the perfusion MRI data and the structure of the provided simulation software are described. This software was reworked, and new methods and parameters were implemented. The key product of this work is a simulation study of focused ultrasound-induced blood-brain barrier opening, comparing the pharmacokinetic models used in this application and the accuracy of their permeability estimates. The results of the simulation study were compared with real-dataset results.
|
|
|
Evaluation of mitochondrial activity in living cells using fluorescence methods
Fedorov, Vasilii ; Mézl, Martin (referee) ; Čmiel, Vratislav (advisor)
Monitoring mitochondrial dynamics can help in the therapeutic treatment of serious diseases and slowing down the aging process. This work was parted into a theoretical part and a practical part. In the theoretical part, research was carried out in the field of mitochondria and methods of activity evaluation. In the practical part in the Python environment, an automatic algorithm for evaluating mitochondrial activity based on the analysis of morphological signs was implemented. The algorithm included image preprocessing, localization of mitochondria, segmentation, and calculation of morphological features such as number of mitochondria, total area, average area, circularity index, eccentricity index. We were able to get and perform an analysis on 16 microscopic images and confirm the success of an algorithm that could be used for drug discovery and testing purposes.
|
|
|
Calculating the Cortical Thickness of Brain by using electrical and mathematical models for Optimal Transcranial Direct Current Stimulation
Hamza, Ali ; Mezl, Martin ; Zafar, Saima
transcranial direct current stimulation (tDCS) is one of the most well-known brain stimulation techniques. In this technique, a constant low intensity (4mA to 5mA) current provides to the brain to modulate the excitability of neurons. There are two categories of tDCS, and both are used for diagnosing different neural disorders, one is anodal stimulation and the other one is cathodal stimulation. Anodal stimulation is used for patients of stroke, epilepsy and depression. Whereas cathodal stimulation is helpful for the obesity, drug addiction and hypertension. The aim of this research was to improve the efficiency of tDCS which depends on the intensity and magnitude of current applied for stimulation. It is important to note that there are numerous variables that can alter the intensity of the current. Some of these variables are hair thickness, head size, skull, tissues thickness, cortical fluid thickness, age, cortical thickness of the brain. In this article, the cortical thickness of the brain is estimated, and the current intensity is calculated for a patient. The Magnetic resonance images (MRI) data of 8 male subjects are analyzed, the raw MRIs are preprocessed, and layers of the head are segmented using MATLAB tool statistical parametric mapping (SPM). After the segmentation of these layers, we calculated the combined thickness of these layers to calculate the desired value of current. The authenticity of our results is compared with the standard current values. Our results shows that the calculated current intensity is closely matched with the standard values and is a direct function of the cortical thickness of brain which is computed from the MRIs. We claim that using our computation, the stimulation current is more accurate and is patient dependent instead of applying the same current to every patient.
|
|
|
Segmentation of optic disc in retinal image data
Juráček, Radek ; Mézl, Martin (referee) ; Odstrčilík, Jan (advisor)
This bachelor thesis is focused on the algorithm of automatic detection of the optical disk in retinal images. It briefly describes the anatomy of the human eye and the principles of scanning the ocular background. The following describes the optical disk segmentation methods. Selected methods are implemented in MATLAB and optimized using a genetic algorithm. A total of five methods were introduced and optimized on the HRF dataset and two experimental datasets.
|
guest ::
