|
|
Autonomous Impedance Meter
Voda, Zbyšek ; Mrázek, Vojtěch (referee) ; Vašíček, Zdeněk (advisor)
This thesis deals with design of a smart embedded device for autonomous measurement of impedance optimized for measurement of biological materials. The goal is to create a device which provides a simple web interface which allows users to capture and further analyze measured data. The digital part is based on MT7688 SoC with WiFi capabilities. The analogue part utilizes a single-chip integrated solution AD5933 that is tightly coupled with a custom analogue frontend whose function is to modify the signal to avoid a potential damage of biological samples. The proposed device is able to either measure impedance for a single frequency or perform a frequency sweep across the whole range beginning at 50Hz and ending at 100 kHz. It supports common two-electrode probes as well as more precise four-electrode probes. The analogue frontend has been simulated using the SPICE simulator to avoid a potential design bug. The experimental evaluation shows that the achieved precision for the typical impedance of biological samples is better than 0.5%.
|
|
|
Validaton of multichannel bioimpedance of vessels using synchronized vascular ultrasonography
Hidegová, Simona ; Kolářová, Jana (referee) ; Mézl, Martin (advisor)
The inclusion of a new device in clinical practice requires an adequate validation. The original publication which introduced multichannel bioimpedance monitor MBM was focused on discribing its technical parameters and demonstration measurements. Further evaluation desires comparision with other standard measuring device. This thesis describes pulse wave measurement by MBM and by other medical devices used for establishing cardiovascular risk. It proposes the validation experiment with synchronized vascular ultrasonography as a reference method. The process of the experimental measurement, aquired data and following data analysis are described in detail. The outputs of the experiment are statistically evaluated. The MBM’s performance and design of the experiment are discussed.
|
|
|
Bioimpedance measurement
Pagáčová, Lenka ; Balogh, Jaroslav (referee) ; Sekora, Jiří (advisor)
The work deals with the body analysis using bioimpedance. The work included theory about bioimpedance and methods associated with the analysis. In the practical part is design of the device for measuring body composition including a software for the microcontroller. The assembled device was tested and compared with commercial product Tanita.
|
|
|
An Electro-Hydrodynamic Model for Bioimpedance Plethysmography
Vyroubal, Petr ; Uruba,, Václav (referee) ; Horák,, Vladimír (referee) ; Maxa, Jiří (advisor)
This doctoral thesis deals with the study of electro-hydrodynamics in the area of numerical modelling of biomechanical systems, concretely in the method of bioimpedance plethysmography. Solving tasks of pulsatile blood flow in the elastic vessel wall is currently one of the most complicated problem in mechanics and biomechanics due to the interaction of two continua on the common boundary. The whole system is additionally loaded by diagnostic electric current. This doctoral thesis was created in cooperation with the Institute of Scientific Instruments of the CAS, v. v. i. Brno with the team engaged in medical signals (the leader Ing. Pavel Jurák, CSc.). Experimental measurements were made independently in the St. Anne's University Hospital Brno in the International Clinical Research Center ICRC and in the Mayo Clinic USA.
|
|
|
Conductive model of human tissue for electroporation purposes
Zelinková, Kateřina - Šarlota ; Cipín, Radoslav (referee) ; Novotná, Veronika (advisor)
This thesis solves the issue of the distribution of the high voltage pulse at the electroporation of the arget ablation zone. For futher examination of influence electroporation was necessary to first understand theoretically electrical charakter of cells and replace with basics eletrical circumferential elements (RLC). Based on this knowledge, theoretical prerequisites for experimental measurements were derived. Theoretical assumptions were then verified by experimental measurements. In the measurement, the assumptions found were confirmed, but significant performance losses were identified. A new catheter was designed to reduce the loss. Because the production of a new catheter is not economically disadvantageous, the properties of the new catheter were first tested using the simulation cloud environment SIMSCALE, where the heating of the heart tissue after the application of the electroporation pulse was monitored. Furthermore, the electroporation process was simulated in the FEMM program, where emphasis was placed on the propagation of cardiac tissue tension.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
Methods of subcutaneous fat measurement
Marek, Vojtěch ; Harabiš, Vratislav (referee) ; Chlíbková, Daniela (advisor)
The thesis studies comparsion of methods of subcutaneous fat measurements. It briefly describes body composition, and deals with research of the most important methods. It describes used devices, which were used. It deals with statistical evaluation of measured data. This thesis approves, that results are different among the devices on statistically significant level, simultaneously there wasnt clear factor, that would have caused it.
|
|
|
The influence of specific futsal preparation on the body composition of Bohemians Prague 1905 futsal players
Ploc, David ; Kinkorová, Ivana (advisor) ; Jandová, Tereza (referee)
Title: The effect of specific futsal preparatory period on the body composition of Bohemians Praha 1905 futsal players Objectives: The main objective of the study was to analyze changes in selected parameters of body composition of the Bohemians Praha 1905 futsal players, which occurred due to specific futsal preparatory period. Methods: The work has the character of an empirical research, the main method is observation. A total of 9 players (1 goalkeeper, 3 defenders and 5 forwards) who played for the Bohemians Praha 1905 futsal club, took part in the research. Basic anthropometric parameters (body height, body weight, BMI) were measured. The BIA method (BIA-Tanita MC 980) was used to obtain input and output data for the analysis of changes in body composition parameters. Statistical data processing (arithmetic mean, standard deviation, tables and graphs) performed in Microsoft Excel. Results: The results of our study show that during the specific futsal preparatory period there were changes in most of the body composition parameters. The only parameter that did not change was fat mass, the value of which remained the same even after a specific futsal preparatory period (12.4 kg). We noted the most significant differences in body weight, which decreased on average by 1.4 kg, and in muscle mass,...
|
guest ::
