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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Rozměřování záznamů EKG s využitím kombinování metod / Delineation of ECG signals using methods combining

Zahradník, Radek January 2014 (has links)
The aim of this work is to study and describe the principles and method of delineation of ECG signals. Learn and describe about method of cluster analysis. In this work was created and described three different methods of delineations of ECG signals. Created algorithms were tested on complete CSE database. With cluster analysis were combine created methods. The obtained results from realized methods and combined method were compared with others known methods. At the end of this work is evaluate efficiency of detection of combined method.
162

Rozměření experimentálních záznamů EKG / Delineation of experimental ECG records

Bucsuházy, Kateřina January 2015 (has links)
This master thesis deals with QRS complex detection and ECG delineation. The theoretical part of this work describes wavelet transform, some of QRS detection approaches and some of ECG delineation approaches. For algorithm realization in Matlab is used redundant dyadic discrete wavelet transform. Algorithm is designed for experimental electrocardiograms of isolated rabbit hearts and it is evaluated through manually determined references.
163

Automatické rozměření signálů EKG / Automatic delineation of ECG signals

Vítek, Martin January 2011 (has links)
This dissertation deals with QRS complex detection and ECG delineation. The theoretical part of the work describes basics of electrocardiography, QRS detection approaches, ECG delineation approaches, the standard CSE database and the wavelet transform theory. The practical part of the work describes designed methods of QRS complex detection and ECG delineation. The designed methods are based on a continuous wavelet transform, appropriate scales, appropriate mother wavelet, cluster analysis and leads transformation. The introduced algorithms were evaluated on the standard CSE database. The obtained results are better, than directly comparable results of other methods and accomplished given database criteria. The robustness of designed algorithms was successfully tested on CSE database signals modified by compression and filtering. The proposed ECG delineation algorithm was successfully used as a tool for evaluation of diagnostic distortion of ECG signals modified by compression.
164

Personnalisation non-invasive de modèles électrophysiologiques cardiaques à partir d'électrogrammes surfaciques / Non-invasive personalisation of cardiac electrophysiological models from surface electrograms

Giffard-Roisin, Sophie 11 December 2017 (has links)
L'objectif de cette thèse est d'utiliser des données non-invasives (électrocardiogrammes, ECG) pour personnaliser les principaux paramètres d'un modèle électrophysiologique (EP) cardiaque pour prédire la réponse à la thérapie de resynchronisation cardiaque. La TRC est un traitement utilisé en routine clinique pour certaines insuffisances cardiaques mais reste inefficace chez 30% des patients traités impliquant une morbidité et un coût importants. Une compréhension précise de la fonction cardiaque propre au patient peut aider à prédire la réponse à la thérapie. Les méthodes actuelles se basent sur un examen invasif au moyen d’un cathéter qui peut être dangereux pour le patient. Nous avons développé une personnalisation non-invasive du modèle EP fondée sur une base de données simulée et un apprentissage automatique. Nous avons estimé l'emplacement de l'activation initiale et un paramètre de conduction global. Nous avons étendu cette approche à plusieurs activations initiales et aux ischémies au moyen d'une régression bayésienne parcimonieuse. De plus, nous avons développé une anatomie de référence afin d'effectuer une régression hors ligne unique et nous avons prédit la réponse à différentes stimulations à partir du modèle personnalisé. Dans une seconde partie, nous avons étudié l'adaptation aux données ECG à 12 dérivations et l'intégration dans un modèle électromécanique à usage clinique. L'évaluation de notre travail a été réalisée sur un ensemble de données important (25 patients, 150 cycles cardiaques). En plus d'avoir des résultats comparables avec les dernières méthodes d'imagerie ECG, les signaux ECG prédits présentent une bonne corrélation avec les signaux réels. / The objective of this thesis is to use non-invasive data (body surface potential mapping, BSPM) to personalise the main parameters of a cardiac electrophysiological (EP) model for predicting the response to cardiac resynchronization therapy (CRT). CRT is a clinically proven treatment option for some heart failures. However, these therapies are ineffective in 30% of the treated patients and involve significant morbidity and substantial cost. The precise understanding of the patient-specific cardiac function can help to predict the response to therapy. Until now, such methods required to measure intra-cardiac electrical potentials through an invasive endovascular procedure which can be at risk for the patient. We developed a non-invasive EP model personalisation based on a patient-specific simulated database and machine learning regressions. First, we estimated the onset activation location and a global conduction parameter. We extended this approach to multiple onsets and to ischemic patients by means of a sparse Bayesian regression. Moreover, we developed a reference ventricle-torso anatomy in order to perform an common offline regression and we predicted the response to different pacing conditions from the personalised model. In a second part, we studied the adaptation of the proposed method to the input of 12-lead electrocardiograms (ECG) and the integration in an electro-mechanical model for a clinical use. The evaluation of our work was performed on an important dataset (more than 25 patients and 150 cardiac cycles). Besides having comparable results with state-of-the-art ECG imaging methods, the predicted BSPMs show good correlation coefficients with the real BSPMs.
165

Parallel Heart Analysis Algorithms Utilizing Multi-core for Optimized Medical Data Exchange over Voice and Data Networks

Karim, Fazal January 2011 (has links)
In today’s research and market, IT applications for health-care are gaining huge interest of both IT and medical researchers. Cardiovascular diseases (CVDs) are considered the largest cause of death for both men and women regardless of ethnic backgrounds. More efficient treatments and most importantly efficient methods of cardiac diagnosis that examine heart diseases are desired. Electrocardiography (ECG) is an essential method used to diagnose heart diseases. However, diagnosing any cardiovascular disease based on the 12-lead ECG printout from an ECG machine using human eye might seriously impair analysis accuracy. To meet this challenge of today’s ECG analysis methodology, a more reliable solution that can analyze huge amount of patient’s data in real-time is desired. The software solution presented in this article is aimed to reduce the risk while diagnosing cardiovascular diseases (CVDs) by human eye, computation of large-scale patient’s data in real-time at the patient’s location and sending the required results or summary to the doctor/nurse. Keeping in mind the importance of real-time analysis of patient’s data, the software system has built upon small individual algorithms/modules designed for multi-core architecture, where each module is supposed to be processed by an individual core/processor in parallel. All the input and output processes to the analysis system are made automated, which reduces operator’s interaction to the system and thus reducing the cost. The outputs/results of the processing are summarized to smaller files in both ASCII and binary formats to meet the requirement of exchanging the data over Voice and Data Networks.
166

The realization of signal processing methods and their hardware implementation over multi-carrier modulation using FPGA technology. Validation and implementation of multi-carrier modulation on FPGA, and signal processing of the channel estimation techniques and filter bank architectures for DWT using HDL coding for mobile and wireless applications.

Migdadi, Hassan S.O. January 2015 (has links)
First part of this thesis presents the design, validation, and implementation of an Orthogonal Frequency Division Multiplexing (OFDM) transmitter and receiver on a Cyclone II FPGA chip using DSP builder and Quartus II high level design tools. The resources in terms of logical elements (LE) including combinational functions and logic registers allocated by the model have been investigated and addressed. The result shows that implementing the basic OFDM transceiver allocates about 14% (equivalent to 6% at transmitter and 8% at receiver) of the available LE resources on an Altera Cyclone II EP2C35F672C6 FPGA chip, largely taken up by the FFT, IFFT and soft decision encoder. Secondly, a new wavelet-based OFDM system based on FDPP-DA based channel estimation is proposed as a reliable ECG Patient Monitoring System, a Personal Wireless telemedicine application. The system performance for different wavelet mothers has been investigated. The effects of AWGN and multipath Rayleigh fading channels have also been studied in the analysis. The performances of FDPP-DA and HDPP-DA-based channel estimations are compared based on both DFT-based OFDM and wavelet-based OFDM systems. The system model was studied using MATLAB software in which the average BER was addressed for randomized data. The main error differences that reflect the quality of the received ECG signals between the reconstructed and original ECG signals are established. Finally a DA-based architecture for 1-D iDWT/DWT based on an OFDM model is implemented for an ECG-PMS wireless telemedicine application. In the portable wireless body transmitter unit at the patient site, a fully Serial-DA-based scheme for iDWT is realized to support higher hardware utilization and lower power consumption; whereas a fully Parallel-DA-based scheme for DWT is applied at the base unit of the hospital site to support a higher throughput. It should be noted that the behavioural level of HDL models of the proposed system was developed and implemented to confirm its correctness in simulation. Then, after the simulation process the design models were synthesised and implemented for the target FPGA to confirm their validation.
167

¿¿¿¿¿¿¿¿¿¿¿¿PROGNOSIS: A WEARABLE SYSTEM FOR HEALTH MONITORING OF PEOPLE AT RISK

Pantelopoulos, Alexandros A. 28 October 2010 (has links)
No description available.
168

A ZigBee-based wireless biomedical sensor network as a precursor to an in-suit system for monitoring astronaut state of health

Dong, Xiongjie January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / Steven Warren / Networks of low-power, in-suit, wired and wireless health sensors offer the potential to track and predict the health of astronauts engaged in extra-vehicular and in-station activities in zero- or reduced- gravity environments. Fundamental research questions exist regarding (a) types and form factors of biomedical sensors best suited for these applications, (b) optimal ways to render wired/wireless on-body networks with the objective to draw little-to-no power, and (c) means to address the wireless transmission challenges offered by a spacesuit constructed from layers of aluminized mylar. This thesis addresses elements of these research questions through the implementation of a collection of ZigBee-based wireless health monitoring devices that can potentially be integrated into a spacesuit, thereby providing continuous information regarding astronaut fatigue and state of health. Wearable biomedical devices investigated for this effort include electrocardiographs, electromyographs, pulse oximeters, inductive plethysmographs, and accelerometers/gyrometers. These ZigBee-enabled sensors will form the nodes of an in-suit ZigBee Pro network that will be used to (1) establish throughput requirements for a functional in-suit network and (2) serve as a performance baseline for future devices that employ ultra-low-power field-programmable gate arrays and micro-transceivers. Sensor devices will upload data to a ZigBee network coordinator that has the form of a pluggable USB connector. Data are currently visualized using MATLAB and LabVIEW.
169

Vorhersagbarkeit von klinischen Ereignissen bei Patienten mit einem implantierbaren Kardioverter-Defibrillator durch Auswertungen aus dem 24-Stunden-Langzeit-EKG / Predictability of clinical events in patients with implantable cardioverter-defibrillator through analysis of 24h-long-term ECG recordings

Wessels, Ansgar Wilhelm 06 July 2016 (has links)
No description available.
170

Fixerade elektroders betydelse för mängden uppkomna artefakter vid 24-timmars långtids-elektrokardiografi-registrering / The significance of fixated electrodes for the amount of artefacts that occur during 24-hour long-term electrocardiography-registration

Sörnmo, Maria, Lind, Julia January 2016 (has links)
Artefakter försvårar analys av långtids-elektrokardiografi-registrering (LTER) och resulterar i en försämrad diagnostisk säkerhet. Minimering av mängden artefakter spelar således en väsentlig roll för ställandet av rätt diagnos. Syftet med denna studie var att jämföra om mängden artefakter, som uppkom vid 24-timmars LTER på patienter, skiljde sig åt med och utan fixering av elektroderna. Populationen bestod av trettio patienter som var inbokade för 24-timmars LTER vid Länssjukhuset Ryhov i Jönköping. Patienterna delades in i två grupper med femton patienter i varje grupp. På grund av fyra externa bortfall bestod det slutgiltiga urvalet av tretton studiedeltagare i vardera gruppen. I grupp A användes ett tubnät för att hålla kablarna på plats och i grupp B fixerades varje elektrod och kabel med Mefix. Grupperna jämfördes sedan avseende mängden artefakter som uppkom under registreringsperioden.  För att analysera om det förelåg någon signifikant skillnad i artefaktuppkomst mellan grupperna användes Wilcoxons rangsummetest. Rangsummorna för respektive grupp beräknades och jämfördes med ett kritiskt intervallvärde. Rangsummorna låg inom intervallet för det kritiska värdet, varpå nollhypotesen ej kan förkastas. Följaktligen förelåg ingen signifikant skillnad i mängden uppkomna artefakter mellan grupperna. På grund av ett litet urval samt brister i undersökningsförfarandet kunde dock inga grundade statistiska slutsatser konkluderas. / Artefacts complicate the analysis of long-term electrocardiography-registration (LTER) and result in a worsened diagnostic accuracy. Thus, minimization of the amount of artefacts plays a vital role in the making of a correct diagnosis. The aim of this study was to compare if the amount of artefacts that occurred during 24-hour LTER on patients, differed with and without electrode fixation.  Thirty patients who underwent a 24-hour LTER, at Länssjukhuset Ryhov in Jönköping, were included in the study and divided into two groups. In group A; a tubular net bandage was used to keep the electrocardiography (ECG) cables in place. In group B, the electrodes and ECG cables were fixated with Mefix. A comparison was made, between the groups, regarding the amount of artefacts that occurred during the registration period.  To analyze if there was a significant difference between the groups, Wilcoxon rank sum test was applied. The result proved to be within the range limits of the critical value, which implies that the null hypothesis cannot be rejected. Hence, there was no significant difference regarding the amount of artefacts that occurred. However, because of a small sample volume and shortfalls in the study procedure, no founded statistical conclusions could be drawn.

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