National Repository of Grey Literature 28 records found  previous11 - 20next  jump to record: Search took 0.01 seconds. 
Photoplethysmography using a smartphone
Dräxler, Vladislav ; Němcová, Andrea (referee) ; Janoušek, Oto (advisor)
The diploma thesis deals with the use of digital photoplethysmography (PPG) technology. The thesis describes the process of acquisition of the photoplethysmographic curve using a smartphone, preprocessing of the PPG signal, calculation of parameters and evaluation of the quality of the obtained data. The practical part includes a measurement protocol for different experimental conditions, describes an algorithm for obtaining a photoplethysmographic curve from video recordings and deals with determining the parameters of the PPG curve and evaluating the quality of the obtained PPG signal. The output of the work is an optimal acquisition protocol for digital scanning of the PPG curve.
Effect of acquisition site compression in multisite photoplethysmography
Hofrová, Lucie ; Kolář, Radim (referee) ; Janoušek, Oto (advisor)
The theoretical part of the thesis describes the pulse wave's origin, the principle of photoplethysmography, and the influence of vein compression on the morphology of the photoplethysmograph caused by external pressure during PPG signal measurement. Furthermore, the thesis contains the measurement and analysis of the PPG bilateral signal, which is used for the evaluation of whether there are differences between the PPG signal measured on the left or the right side of the human body. A dataset consisting of 10 volunteers was created for evaluation. The practical part contains the algorithm which analysis the PPG signal. Furthermore, normalization and statistical analysis is performed. The results show that external pressure has an effect on pulse wave width analysis and heart rate. When the pressure is high, the ability of pulse wave analysis is impaired.
Breathing Rate Estimation from the Photoplethysmogram
Petrík, Jakub ; Králík, Martin (referee) ; Kozumplík, Jiří (advisor)
The main topic of this bachelor thesis are methods for breathing rate estimations from photopletysmographic signals. In the theoretical part of the thesis we find a biref review of methods that are used for breathing rate estimation. These methods are than tested and their performance is evaluated on two pubilc databases BIDMC and CapnoBase. These databases also contain reference values of respiratory rate.
Vital Signs Monitoring
Kratochvíl, Pavel ; Mrázek, Vojtěch (referee) ; Vašíček, Zdeněk (advisor)
Cieľom tejto práce je navrhnúť dizajn, implementovať prototyp a evaluovať funkčnosť systému pre monitorovanie životných funkcií. Navrhnuté riešienie je založené na Bluetooth Low Energy Mesh sieti, v ktorej sa nachádzajú zariadenia štyroch typov: batériou napájané nositeľné monitorovacie zariadenie zbierajúce fotopletysmografické dáta zo senzora a rozosielajúce extrahované informácie o frekvencii srdcového tepu a periférneho okysličenia subjektu do mesh siete; zariadenia preposielajúceho dáta v sieti (relay node); nosného zariadenia konfigurujúceho mesh sieť pri jej inicializácii (provisioner node) a koncového zariadenia, ktoré odosiela dáta prijaté v mesh sieti pomocou protokolu MQTT na internet. Batériou napájané monitorovacie zariadenia sú implementované na module nRF52833 od firmy Nordic Semiconductor, zatiaľ čo koncové zariadenia komunikujúce cez MQTT protokol využívajú ESP32 moduly od firmy Espressif. Analýza zozbieraných PPG dát je dosiahnutá dvojitou filtráciou (spredu a zozadu) pomocou Chebyshev II band-pass filtra štvrtého rádu, následovanou vyhladením dát s použitím kĺzavého priemeru a extrakciou indikátorov životných funkcií algoritmom s jediným priechodom v nazbieraných vzorkách. Vďaka výbornej energetickej úspornosti zariadení a minimálnej vyžadovanej infraštruktúre predstavuje navrhnutý systém vhodné riešenie pre zdravotnícke zariadenia s obmedzenými finančnými zdrojmi.
Interface for plethysmographic sensor
Špánik, Šimon ; Barcík, Peter (referee) ; Kolka, Zdeněk (advisor)
The bachelor's thesis deals with the topic of photoplethysmography and the signal produced by the photoplethysmographic sensor. The goal is to design a laboratory device that would serve as an interface between a photoplethysmographic sensor and a computer. The work describes the anatomy and function of the human heart, the principle of photoplethysmography, and the properties of the sensor in terms of input and output signals. Also presented here is the method of powering and filtering the relevant circuits in the form of an additional printed circuit board for a standard Arduino microprocessor module, which is powered by USB. Furthermore, in the work, it is possible to find a solution to the influence of unwanted signals using filter analog circuits and the minimization of the measured signal's own noise, which prevents the signal from continuous values to discrete time and subsequent storage using a computer application on the data storage for subsequent signal processing.
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.
Visualization and analysis of retinal pulsatile phenomena
Plavcová, Daniela ; Odstrčilík, Jan (referee) ; Kolář, Radim (advisor)
Retinal blood flow can be a reflection of the state of the vascular system, but it can also indicate changes in intracranial pressure. For that reason, video sequences are taken from the retina, which can be processed to examine this area. This work deals with the analysis and visualization of pulsations on the retina, representing the change in light attenuation during one hearth cycle, and the search for suitable parameters describing connections and differences between data, whether in the form of signals, images or video sequences.
Photoplethysmography using a smartphone
Dräxler, Vladislav ; Němcová, Andrea (referee) ; Janoušek, Oto (advisor)
This work is focused on the PPG technology using a smartphone, from the acquisition of the photoplethysmographic curve, through the preprocessing of the PPG signal, the calculation of the parameters to the quality assessment. The practical part contains a measurement protocol under different experimental conditions, an algorithm for obtaining a photoplethysmographic curve from video recordings obtained by measurement, and further deals with determining various parameters and evaluating the quality of the obtained PPG signal. The output of the work is an optimal acquisition protocol for scanning the PPG curve.
Advanced sleep quality estimation
Benáček, Petr ; Ředina, Richard (referee) ; Filipenská, Marina (advisor)
This thesis deals with the assessment of sleep quality using modern deep learning methods. The thesis describes metrics for automatic classification of sleep stages. A selected database of sleep data is discussed. Due to the low number of data in the wakefulness phase, different methods of data augmentation are described and implemented. Models based on 1D convolutional networks are the basis for the classification. As a result, models for binary classification and classification of 3 and 4 sleep phases are prepared. Finally, sleep quality metrics are calculated using these models and the results are compared with the literature.
HRV analysis based on PPG signal
Martinů, Žaneta ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
The thesis deals with the detection of systolic and diastolic peaks of pulse waves in a photoplethysmographic database. The detectors are implemented in MATLAB. The following part of the thesis uses the signal delineation of the photoplethysmographic signal to determine pulse rate variability. The final part of the thesis evaluates the use of pulse rate variability and compares it to the heart rate variability.

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