Wyniki 11-17 spośród 17 dla zapytania: authorDesc:"Adam JÓŚKO"

ECG signal quality improvement techniques

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The problem of the presentation of ECG signals is discussed in the paper. The signal itself, beside the pure ECG content, often encapsulates artefact components with a physiological and technical origin. The latter element is the subject of Authors' research. The main goal is to develop dedicated filtering technique to reject low frequency artefact components including signal wandering as well as high frequency components with power line and radio interferences and noise. Streszczenie. W artykule przedstawione zostały zagadnienia związane z prezentacją sygnałów elektrokardiograficznych. W zapisie mogą wystąpić artefakty zarówno fizjologiczne jak i techniczne. Ta druga grupa zakłóceń jest przedmiotem badań Autorów. Głównym ich celem jest opracowanie techniki filtracyjnej, która pozwoli na usunięcie składowych zarówno wolnozmiennych (trend sygnału), jak i szybkozmiennych (zakłócenia interferencyjne sieciowe i stochastyczne). (Techniki poprawy jakości sygnałów EKG) Keywords: ECG signal automated analysis, Signal processing and denoising, Adaptive filtering Słowa kluczowe: Automatyczna analiza sygnału EKG, Przetwarzanie i odszumianie sygnałów, Filtracja adaptacyjna Introduction Recently there have been observed permanent interest in the field of the automatic processing and analysis of biomedical signals[1,2,3]. The electrocardiogram is of course within the scope of the mentioned class of signals. The ECG signal reflects the electrical activity of the heart muscle observed from the body surface. ECG examination is a very meaningful and important element of cardiac diagnosis. It is possible to verify and evaluate normal cardiac function as well as distinguish a huge spectrum of symptoms and cardiac muscular dysfunctions, including serious pathologic cases head up with acute myocardial infarction. Recorded ECG signal suffers from presence of complex sources of disturbances which deteriorate quality of desired pure ECG content and make it[...]

Adaptive ECG signal denoising approach in the initial signal processing stage of electrocardiograph system DOI:10.15199/48.2015.07.03

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Autorzy prezentują model laboratoryjny podejścia do automatycznego oczyszczania sygnałów EKG. Struktura ta skonstruowana jest w postaci zestawu elementów realizujących przy relatywnie niskiej złożoności obliczeniowej ocenę poziomu szumu, dobierając tym samym w sposób płynny odpowiedni zestaw współczynników filtrów. Abstract The research presents a concept/laboratory model of the proposed approach to ECG signal denoising. An adaptive module is designed for the pre-processing ECG signal enhancement and noise rejection. The research aims at the proposal of the processing method for removing these distortions with relatively low computational complexity. (Adaptacyjna eliminacja zakłóceń sygnału ECG na początkowym etapie przetwarzania). Słowa kluczowe: EKG, automatyczna eliminacja zakłóceń, określenie jakości sygnału, SNR, estymata szumu. Keywords: ECG, Automated artefacts elimination, Signal quality determining and improvement, Adaptive filtering, noise estimate. Introduction The paper presents a concept/laboratory model for an adaptive raw ECG signal denoising front-end module which is intended to deliver possibly pure ECG signals. During a typical patient diagnostic process, the ECG signal is distorted by various types of disturbances in clinical environment. One can divide them into the physiological artefacts (i.e. muscle tremor, patient's breathing and movement) and technical artefacts (i.e. noise of the signal conditioning input circuit, electrode electrical contact dysfunction, power line interferences and electromagnetic high frequency interferences. Consequently, these factors have crucial influence on quality of detection important ECG parameters resulting in final diagnosis of automated analysis. System structure Article covers selected problems of Authors proposal structure of the digital ECG signal fr[...]

Classic, adaptive filtering techniques in the ECG signal enhancement DOI:10.15199/48.2015.07.04

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Artykuł przedstawia wyniki prac w zakresie eliminacji zakłóceń z sygnału elektrokardiograficznego (EKG). Zakłócenia te charakteryzują się zmiennością zarówno w czasie jak i w częstotliwości. Dodatkowo własności widmowe pokrywają sie z własnościami użytecznego sygnału pomiarowego. Fakt ten jest bardzo niepożądany w aspekcie skutecznej analizy i diagnostyki sygnałów EKG. Zatem z uwagi na różnorodność i zmienność charakteru zakłóceń filtracja adaptacyjna wydaje się być odpowiednim narzędziem skutecznie poprawiającym jakość sygnału. Abstract. The paper presents Authors’ investigations in the field of the Electrocardiography (ECG) signal noise reduction. The distortions of ECG signal recordings are changing both in time and frequency and their frequency properties overlap the frequency spectrum of the pure ECG signal. This effect is very unfavourable in terms of the effective ECG signal analysis and diagnostic. As the properties of the ECG signal distortions are nonstationary, adaptive techniques for their rejection seems to be adequate in the purpose. (Zastosowanie klasycznych technik filtracji adaptacyjnej w przetwarzaniu sygnałów elektrokardiograficznych). Słowa kluczowe: przetwarzanie sygnałów EKG, redukcja zakłóceń filtracja adaptacyjna. Keywords: ECG signal processing, noise reduction, adaptive filters. Introduction ECG signal is the one of the highest factor of importance from the medical diagnos[...]

Nanosecond EMP simulator using a new high voltage pulse generator DOI:10.15199/48.2017.10.07

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The design of reliable electrical systems is not a simple task, especially in some sensitive domains which demand high-security level like aeronautics and aerospace or for those working in very severe conditions such as the military equipment. Therefore, several standards and norms have been elaborated in order to normalise the tests’ conditions that the system should sustain in order to be approved, in particular, those tests connected with the electromagnetic compatibility (EMC). In our case, we are interested in the checking of the susceptibility of a designed system to the electromagnetic radiated pulses (EMPs) like those created by nuclear explosions or some electromagnetic weapons in order to confirm its ability to work in electromagnetic hostile environments. For that purpose, it’s very important to reproduce, in the lab, artificial conditions where the tests could be carried out. The presented paper is a part of a general project of developing a test bench (simulator) capable of producing EMPs. It’s devoted to explain the primary designed solution, present the constructed prototype, discuss the experimental results and measurements done in the lab and comparing them with the results obtained from simulation. In this work, we mainly focus on the connection between the high voltage pulse generator and the antenna, which can be done using different alternatives such as a direct connection without any intermediate or using some kind of pulse forming networks or transmission lines to adjust the impedance between the generator and the antennas. The chosen solution depends on several parameters like the generator impedance, the distance between the generator and the antennas, the frequency range (i.e wavelength)...etc. The second point discussed in this paper is the measurement of the radiated EMP.using a fast free field D-dot probe, which is a convenient way to measure the high amplitude electrical field[...]

QRS detector approach for on-line purposes

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The problem of real time restrictions and effectiveness requirements of the QRS detection algorithm is presented in the paper. Several approaches were taken into account and were tested during the research. CSE ECG databases were used as test signal set. FIR and IIR filters were investigated as well as different filter coefficients floating point data types. The paper summarises Authors’ investigations in the field of QRS detector application to the contemporary market platform. Streszczenie. W artykule przedstawione zostały zagadnienia dotyczące wymagań stawianych algorytmom do detekcji zespołów QRS, przeznaczonych do pracy w czasie rzeczywistym. Szczególnie ważne są przeciwstawne problemy, które dotyczą skuteczności pracy algorytmu i szybkości jego działania. W trakcie testów wykorzystano wiele rozwiązań bazujących na filtrach SOI oraz NOI oraz różnych formatach współczynników filtrów. (Zagadnienia pracy w czasie rzeczywistym algorytmu do detekcji zespołów QRS) Keywords: ECG signal automated analysis, QRS complex detection, QRS detection testing and evaluation stage, Real time algorithms Słowa kluczowe: Automatyczna analiza sygnału EKG, Detekcja zespołów QRS, Testy detektorów QRS, Algorytmy czasu rzeczywistego Introduction The article concerns the development results of real time ECG analysis algorithm. Proposed solution is dedicated for QRS complex detection and is characterised by two opposing properties. The first one is the ability of stable and uninterrupted functioning on a dedicated low cost platform, in a real time at desired sampling frequency and with the complete set of the ECG signals (leads). The second one is the requirement of the satisfactory level of the detection error rate. The recent parameter should not be lower than 90 % (initial assumption) - if tested on the Measurement and Diagnostics CSE ECG databases. The paper summarises Authors' investigations in the field, together with achieved results and deduc[...]

Detection algorithm for pacemaker impulses identification and localisation

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The article concerns the description of effective pacemaker excitations detection and remover signal processing. The main goal was to provide reliable software module which will be implemented in real industrial cooperant's medical system. Considered DSP algorithm was tested with CSE database signals mixed with contaminations stated in EN 60601-2-51. Streszczenie. Artykuł skupia się na prezentacji efektywnego algorytmu detekcji i usuwania impulsów kardiostymulatora z sygnałów EKG. Główny cel jaki sobie postawiono był ukierunkowany na opracowanie pewnego i stabilnego modułu softwarowego pozwalającego na wykorzystanie go w rzeczywistym systemie medycznym kooperanta z branży medycznej. Przedstawiony algorytm został dodatkowo przetestowany na danych zaburzonych sygnałami definiowanymi przez normę EN 60601-2-51. (Algorytm do identyfikacji i lokalizacji impulsów kardiostymulatora). Keywords: ECG signal automated analysis, PM detection, Removing PM impulses form ECG data, EN 60601-2-51 Słowa kluczowe: Automatyczna analiza sygnału EKG, Detekcja zespołów kardiostymulatora, Usuwanie zespołów kardiostymulatora z danych przeznaczonych do detekcji zespołów QRS, EN 60601-2-51 The paper deals with signal processing devoted to pacemaker excitations detection/removal from sampled ECG signals, used prior to the followed diagnosis oriented DSP. With presented DSP two goals are achieved:  The presence of active cardiac pacemaker can be detected for the case of the non-cooperative patient,  The standard, diagnosis oriented following DSP (and ECG instrumentation) can be used for the wide spectrum of patients, independent of their heart treatment history (PM installations). With the development in modern cardiology there is a growing implementation of extremely [...]

D-dot, B-dot Data Processing of Fields Generated with Broadband Pulsed Antenna DOI:10.15199/48.2019.11.29

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During our attempt to build a jamming system based on electromagnetic pulse (EMP) system [1], we had to measure the radiated electrical and the magnetic fields using fast D-dot and B-dot probes [2]. These measurements were necessary to confirm that the jammer is really radiating and also to get more information about the frequency range and the power density of the generated waves. After recording data, we faced two major problems. The first one is that the two curves do not start at the same time. This difference is caused by the delay in the optical links which are not the same for both sensors and additionally by the propagation time in the conditioning circuit. The second problem was to find the ratio between the two signals, because the irregular form of the signals made it difficult to describe them in a parametrized form. The first problem was solved with calculating and maximizing the correlation between the two. The second issue was approached as a single variable optimization problem, in which we tried to minimize the distance between the electrical field data and the magnetic field data. If there is a propagation, this optimization variable would fit to the intrinsic impedance of the air for the far field mode. Recording data at different distances from the antenna allowed us to analyze the attenuation of the near field static component and the building up of the far field. Description of the EMP generator and the measurement setup The experimental setup consists of two main parts: a high voltage pulse generator connected directly to a broadband antenna, which contains the Electromagnetic pulse (EMP) generator, or in other words, the jammer. In the second part, the radiated field is sensed and recorded via free field D-dot and a B-dot probes located nearby the antenna. The probes are connected to fast oscilloscope with a 40 GS per second using an optical link. The oscilloscope is located inside a shielded cont[...]

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