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Bioimpedance signal processing
Valíčková, Vladimíra ; Vondra, Vlastimil (referee) ; Soukup, Ladislav (advisor)
Theoretical part of this Bachelor thesis deals with properties measurement and use of bioim-pedance signal for medical diagnostics. The practical part deals with detection of important points in derivate bioimpedance signal that may be further used in various medical applicati-ons. This work compares three detection methods. The best results were achieved by a de-tection with fixed interval there were excluded only 1,09 % values. Very similar results had detector dependent on constant bioimpedance. Here was excreted 1.18 % of detections. Algo-rithms that are dependent on length of RR interval perform worse. Furthermore, there is cal-culated the Pulse wave velocity in six parts of the human body in a horizontal and tilt patient position. In the tilt position were the pulse wave velocity about 38.59 % faster than in hori-zontal.
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Solid State Power Amplifier for the L-Band
Pecen, Vojtěch ; Vondra, Vlastimil (referee) ; Kasal, Miroslav (advisor)
The goal of this diploma's thesis is to create a design of a two stages amplifier working in a band reserved for the secondary surveillance radar at the frequency of 1090 MHz. Output power of the amplifier should be 20 W and efficiency should be as high as possible. Because of this the second stage is designed in class C. Contents of this diploma's thesis include a theoretical analysis, simulations of the amplifier parameters, comparison of the Ansys Designer and AWR Microwave Office simulation programs and design of both stages of the amplifier, followed by a comparison of the measured parameters with the simulations.
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Properties of pulse wave velocity in human body during various excitations
Matejková, Magdaléna ; Halámek, Josef (referee) ; Vondra, Vlastimil (advisor)
The thesis is concerned with the analysis of measuring pulse wave velocity in human body with the aid of whole-body multichannel bioimpedance which was developed at ISI AS CR, v.v.i.. The evaluation of pulse wave velocity can provide us with important information about the state of vessel compliance which is one of the basic parameters informing on their physiological state. The examination of the state of vascular system is a very important part of early diagnostics because its pathological states are the main contributor to the rise of cardiovascular diseases and disease mortality. The thesis is concerned with the theoretical analysis together with the available methods of valuation of the state of vascular system that use measuring of pulse wave velocity. The main part of the thesis deals with the analysis of the whole-body multichannel bioimpedance measurement. The proposed and programmed protocol that summarizes and visualizes all obtained information is a part of this thesis. This is currently used as an output of the experimental measurement by this method. Data file for statistical processing contains the values of the pulse wave velocity of 35 healthy volunteers and subsequently the properties of pulse wave are assessed at various excitations.
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Low Noise Amplifier for the S Band
Benites Ayala, Ivan Alejandro ; Vondra, Vlastimil (referee) ; Kasal, Miroslav (advisor)
This master's thesis presents the design and the realization of a low noise amplifier (LNA) for the S band of radio frequency spectrum from 2.3 GHz to 2.4 GHz. This thesis is mainly focused on stability and impedance matching networks study. Ansoft Designer and ANSYS HFSS programs are used for this design to simulate the LNA. Different low noise devices are simulated in order to find the best results for the final design. Moreover, a coaxial cavity resonator is designed in the input of the LNA and works as a band pass filter. Finally, the LNA is fabricated and its properties compared with the simulation results.
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Automatic determination of the pulse wave velocity in a body segment
Kampo, Dávid ; Svačinová, Jana (referee) ; Vondra, Vlastimil (advisor)
This Bachelor´s thesis deals with a propagation of a pulse wave velocity in different body segments and its measurement through bioimpedance. In connection with this topic, the work includes a profound description of a pulse wave and its velocity in regards to diagnostics and prevention of cardiovascular diseases that have been prevailing in recent years. During the process of determination of PWV, ECG is recorded, as it helps to accurately estimate the relevant transition times and the reulting PWV. The main purpose of this work is to validate that PWV can be determined without supportive ECG signals, what as a result makes the whole process simpler, more effective and available. The main target of this work has been successfully achieved and the algorithm for an evaluation of transition times and determination of PWV is described in the work. Moreover, the algorithm is implied to the structure of GUI in Matlab programm where the interface has been designed to suit the user´s needs to analyse PWV. Highlighting the validation process and functionality of the algorithm, signals from 21 subjects have been used to assess some of the most frequent analysed PWVs and all average values of velocities are within a physiological range from 5 m/s to 15 m/s. cfPWV is considered as a golden standard when it comes to PWV and the average value for all 21 subjects has been estimated to 7,54 m/s what corresponds with values from scientific studies that have been assessing cfPWV.
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Modelling of cardiac impedance signals
Matušek, Adam ; Vondra, Vlastimil (referee) ; Provazník, Ivo (advisor)
Tato diplomová práce se zabývá vytvořením modelu signálu impedančního měření srdce (ICG signál). Impedanční kardiografie podává informaci o změně srdečního objemu během srdečního cyklu. Modelování signálu předchází statistická analýza vzájemné pozice ICG signálu vzhledem k dalším mechanickým srdečním signálům. Konstrukce modelu vychází z reálných nasnímaných signálů. Konečný ICG model je začleněn do již existujícího modelu mechanických interakcí mezi srdcem a plícemi. Výsledkem je funkční model kardio-respiračních interakcí, který bude sloužit v dalších částech výzkumu laboratoře PRETA.
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SMV-2022-61: Development of advanced programmable acquisition system with pulse generator
Vondra, Vlastimil
Assessment of the equipment specification in terms of the equipment implementation possibilities using the contractor's instrumentation. Analysis of the requirements of the assignment and development of the generator solution methodology. Preparation of a proposal for implementation according to the desired characteristics. Manufacturing mechanical and electrical parts and purchasing the necessary components. Verification of theoretical initial requirements by practical measurements at a designated location. Assembling 1 piece of experimental equipment. Installation, calibration of equipment at the filling site. Operator training at the client's.
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Automatic determination of the pulse wave velocity in a body segment
Kampo, Dávid ; Svačinová, Jana (referee) ; Vondra, Vlastimil (advisor)
This Bachelor´s thesis deals with a propagation of a pulse wave velocity in different body segments and its measurement through bioimpedance. In connection with this topic, the work includes a profound description of a pulse wave and its velocity in regards to diagnostics and prevention of cardiovascular diseases that have been prevailing in recent years. During the process of determination of PWV, ECG is recorded, as it helps to accurately estimate the relevant transition times and the reulting PWV. The main purpose of this work is to validate that PWV can be determined without supportive ECG signals, what as a result makes the whole process simpler, more effective and available. The main target of this work has been successfully achieved and the algorithm for an evaluation of transition times and determination of PWV is described in the work. Moreover, the algorithm is implied to the structure of GUI in Matlab programm where the interface has been designed to suit the user´s needs to analyse PWV. Highlighting the validation process and functionality of the algorithm, signals from 21 subjects have been used to assess some of the most frequent analysed PWVs and all average values of velocities are within a physiological range from 5 m/s to 15 m/s. cfPWV is considered as a golden standard when it comes to PWV and the average value for all 21 subjects has been estimated to 7,54 m/s what corresponds with values from scientific studies that have been assessing cfPWV.
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Evaluation of pulse Wave Velocity Based on Whole-Body Bioimpedance
Soukup, Ladislav ; Tyšler, Milan (referee) ; Vrba, Jan (referee) ; Vondra, Vlastimil (advisor)
This thesis deals with the methodology of use of whole-body impedance cardiography for evaluation of pulse wave velocity. The first three chapters explain selected hemodynamic properties of the arterial system related to the issue of pulse wave propagation. At the same time the ordinary methods for estimation, its disadvantages and merits has been summarized. Points at issue of whole-body impedance evaluation methodology for pulse wave velocity are researched in second part of this thesis. In order that analysis the procedure for correct methodology has been determined. Particularly determination of reference proximal point for calculation of transit time towards aortic valve, and design and accuracy of transit distance measurement were discussed. Based on the obtained data, a calculation of representative pulse wave velocity to eight limb locations was performed.
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