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Wyszukujesz frazę "Wrobel, J" wg kryterium: Autor


Tytuł:
Data partitioning based weighted averaging for noise suppression in biomedical signals
Autorzy:
Momot, A.
Jezewski, J.
Wrobel, J.
Powiązania:
https://bibliotekanauki.pl/articles/951703.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
ważone uśrednianie
tłumienie hałasu
weighted averaging
noise attenuation
quasi-cyclic biomedical signal
Opis:
In the case of biomedical signals with a quasi-cyclic character, such as electrocardiographic signals, the high resolution electrocardiograms or electrical potentials recorded from the nervous system of patients (estimating brain activity evoked by a known stimulus), as a method of averaging in the time domain may be used for noise attenuation. In this paper there is presented input data partitioning applied to a few different methods of weighted averaging. This procedure usually leads to improve the quality of the resulting averaged signal, especially when fuzzy partitioning is used. Below it is presented the computational study of weighted averaging with traditional (sharp) and fuzzy partition of the input data in the presence of non-stationary noise. The performance of presented methods is experimentally evaluated for analytical signal of EN 60601-2-51 (2003), namely ANE20000 ECG record.
Źródło:
Journal of Medical Informatics & Technologies; 2012, 20; 85-91
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fetal state evaluation with fuzzy analysis of newborn attributes using CUDA architecture
Autorzy:
Czabański, R.
Wróbel, J.
Jeżewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/333255.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
fuzzy systems
fetal monitoring
support vector machines
CUDA architecture
systemy rozmyte
monitorowanie płodu
architektura CUDA
Opis:
Cardiotocography is a biophysical method of fetal state evaluation involving the recording and analysis of the fetal heart rate (FHR). Since a proper interpretation of the signal is relatively difficult, an automatic classification is often based on computational intelligence methods. The quality of classifiers based on supervised learning algorithms depends on a proper selection of learning data. In case of the fetal state evaluation, the learning is usually based on a set of quantitative parameters of FHR signal and the corresponding reference information determined on the basis of the retrospective analysis of newborn attributes. Values of the single attribute have been used so far as a reference. As a result, a part of information on the actual neonatal outcome has always been lost. The following paper presents a method of the fuzzy reasoning leading to an evaluation of neonatal outcome as a function of three newborn attributes. The fuzzy system was used in the process of a qualitative evaluation of the fetal state based on quantitative analysis of FHR signal using a support vector machine (SVM). In order to improve computational effectiveness, the learning algorithm was implemented in Compute Unified Device Architecture (CUDA). The results of these studies confirm the effectiveness of the proposed method and indicate the possibility of practical usage of the fuzzy system in supervised learning algorithms for the qualitative evaluation of the fetal state.
Źródło:
Journal of Medical Informatics & Technologies; 2013, 22; 125-133
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inconsistency in evaluation of clinical patterns in fetal heart rate waveforms
Autorzy:
Jeżewski, J.
Horoba, K.
Wróbel, J.
Gacek, A.
Powiązania:
https://bibliotekanauki.pl/articles/333801.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
monitorowanie płodu
tętno płodu
przyspieszanie / zwalnianie
fetal monitoring
fetal heart rate
acceleration/deceleration
expert inconsistency
Opis:
Acceleration and deceleration patterns in fetal heart rate (FHR) are widely used as an assessment of fetal condition. The basis for both visual and automated quantitative analysis is correctly determined fetal heart rate baseline. There are many methods for automated fetal heart rate baseline estimation. Since there are no definitive criteria or "gold standard" to evaluate algorithms for baseline determination, a clinical expert could be considered as a reference. Taking into account that not the shape of baseline itself but the results of quantitative analysis obtained using this baseline are important, we stated that such evaluation should be done only on the basis of comparison of effects - the recognized accelerations and decelerations. However, the first step for such comparison is to check how well expert meets established FIGO definition of accelerations and decelerations patterns in FHR trace. The paper presents a method for evaluation of expert's interpretation of these definitions. Two indices describing the inconsistency among fetal monitoring system and experts have been defined. The results obtained indicate the essential differences in procedure of accelerations/decelerations recognition by the computerized system and human expert.
Źródło:
Journal of Medical Informatics & Technologies; 2002, 4; MT27-35
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method of ensuring data integrity in a data stream management system
Autorzy:
Widera, M.
Wróbel, J.
Widera, A.
Matonia, A.
Powiązania:
https://bibliotekanauki.pl/articles/333295.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
zarządzanie integralnością systemu baz danych
biomedyczne strumienie danych i przetwarzanie sygnałów
database management system integrity
biomedical data stream and signal processing
Opis:
Assurance of data integrity is one of the prerequisites for each computer system. The paper presents a method enabling on-line maintenance of stream data set integrity. This method is implemented in a data stream management system prototype designed to find application in a biomedical monitoring system. In the case of medical computer systems assurance of data integrity is particularly important for documenting formal results and for the patient's safety.
Źródło:
Journal of Medical Informatics & Technologies; 2004, 8; MM141-148
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving the quality of the fetal state assessment with epsilon-insensitive learning methods
Autorzy:
Czabański, R.
Wróbel, J.
Jeżewski, J.
Łęski, J.
Powiązania:
https://bibliotekanauki.pl/articles/333468.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
fetal monitoring
fuzzy implication
epsilon-insensitive learning
monitorowanie płodu
implikacja rozmyta
Opis:
Recording and analysis of fetal heart rate (FHR) signal is nowadays the primary method for the biophysical assessment of the fetal state. Since the correct interpretation of crucial FHR characteristics is difficult, methods of automated quantitative signal evaluation are still the subject of the research studies. In the following paper we investigated the possibility of improvement of the fetal state evaluation on the basis of the epsilon-insensitive learning (eIL). We examined two eIL procedures integrated with fuzzy clustering algorithms as well as different methods of logical interpretation of the fuzzy conditional statements. The quality of the FHR signal classification was evaluated using the data collected with the computerized fetal surveillance system. The learning performance was measured with the number of correct classification (CC) and overall quality index (QI) defined as a geometric mean of sensitivity and specificity. The obtained results (CC = 88 % and QI = 87 %) show a high efficiency of the fetal state assessment using the epsilon-insensitive learning based methods.
Źródło:
Journal of Medical Informatics & Technologies; 2014, 23; 19-26
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fuzzy system for evaluation of fetal heart rate signals using FIGO criteria
Autorzy:
Czabański, R.
Jeżewski, M.
Wróbel, J.
Jeżewski, J.
Horoba, K.
Powiązania:
https://bibliotekanauki.pl/articles/333142.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
monitoring płodu
tętno płodu
kryteria FIGO
fetal monitoring
fetal heart rate
signal classification
fuzzy systems
Opis:
Cardiotocography is a biophysical method of fetal monitoring during pregnancy and labour. It is mainly based on recording and analysis of fetal heart activity. The computerized fetal monitoring systems provide the quantitative description of the recorded signals but the effective methods supporting the conclusion generation are still needed. The evaluation of the signal can be made using criteria recommended by FIGO. Nevertheless, the quantitative description of the traces is inconsistent with qualitative nature of the obstetric knowledge. Therefore, we applied the fuzzy system based on Takagi-Sugeno-Kang model to evaluate and classify signals. FIGO guidelines were used for developing a set of fuzzy conditional rules defining the system performance. The proposed system was evaluated using data collected with computerized fetal surveillance system – MONAKO. The classification results confirm the improvement of the fetal state evaluation quality while using the proposed fuzzy system support.
Źródło:
Journal of Medical Informatics & Technologies; 2009, 13; 189-194
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of obstetrical surveillance systems for effective patient management and home-care of at-risk pregnancy
Autorzy:
Roj, D.
Wróbel, J.
Horoba, K
Kotas, M.
Przybyła, T.
Powiązania:
https://bibliotekanauki.pl/articles/333134.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
nadzór płodu
telemedycyna
ciąża zagrożona
monitoring domowy
fetal surveillance
telemedicine
high-risk pregnancy
home monitoring
Opis:
The paper presents some aspects of telemedical fetal monitoring where the biomedical signals are acquired remotely at patient’s home and wirelessly transmitted to the central computer through the GSM network and Internet. Signals are acquired during the monitoring sessions, and along with analysis results, they create uniform data structure describing the medical history of patient since the first monitoring to the labour. The proposed structure of database was based on the currently used in centralized monitoring systems, and extended by information essential for remote monitoring purposes. Internet-based telemedical systems allow for remote access to collected data, however, it is necessary to secure the database against unauthorized access to patient’s personal data and medical history. The proposed structure of database records allows for easy searching and viewing of patient data forms and monitoring traces. These features cause that the database constitutes valuable research material, which enables to relate parameters of particular monitoring records, acquired during pregnancy, to the real fetal outcome.
Źródło:
Journal of Medical Informatics & Technologies; 2009, 13; 201-206
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Filtering of two-dimensional digital images using weighted averaging for adaptive selection of weights
Autorzy:
Momot, A.
Wrobel, J.
Horoba, K.
Jeżewski, M.
Bernys, M.
Powiązania:
https://bibliotekanauki.pl/articles/951702.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
filtracja obrazów
ważone uśrednianie
image filtering
weighted averaging
adaptive selection of weights
Opis:
Many digital images, especially in biomedical fields, contain some disturbances. The image analysis depends on quality of the images that is why reduction or elimination (if it is possible) the disturbances is the key issue. There are many methods of improvement in the quality of the images and thus improve the quality of the image analysis, among them one of the simplest method is low-pass filtering such as arithmetic mean or its generalization, weighted mean. The basic problem of the weighted mean is the proper selection of the weights. This can be done using adaptive algorithms. This paper presents several such algorithms which are modifications of the existing weighted averaging methods created originally for noise reduction in electrocardiographic signal. The description of the new filtering methods and a few results of its application are also presented with comparison to existing arithmetic average filtering.
Źródło:
Journal of Medical Informatics & Technologies; 2012, 20; 93-99
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monitoring of fetal movements based on actogram signal analysis
Autorzy:
Kupka, T.
Matonia, A.
Wróbel, J.
Horoba, K.
Jeżewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/333340.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
USG Dopplera
aktogram
aktywność ruchowa płodu
tętno płodu
Doppler ultrasound
actogram
fetal movement activity
fetal heart rate
Opis:
At present, biophysical fetal monitoring relies mainly on evaluation of a fetal heart rate (FHR). Absence of the FHR variability indicates central nervous system depression associated with hypoxia. The analysis of fetal heart rate segments identified with the aid of information on fetal movement activity provides much better results than analysis of the whole signal. Automatic recording of the fetal movement activity in a form of actogram signal provided by new models of fetal monitors becomes very common. For evaluation of information content of the actogram signal, the measurement instrumentation has been developed. The examined group comprised 20 patients and the total time of recording was 10 hours. Correlation between movements observed by clinical experts on ultrasonographic image and actogram trace recorded by fetal monitor was analysed. Although for head, arms, legs and trunk movements just visual analysis let observe their correlation with actogram signal, but in case of breathing movement no correlation was noted. Depending on movement type the detection efficiency was in range from 54 % to 80 %.
Źródło:
Journal of Medical Informatics & Technologies; 2004, 8; MM119-128
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of generalized filters for estimation of fetal heart rate baseline
Autorzy:
Pander, T.
Przybyla, T.
Wrobel, J.
Jezewski, J.
Roj, D.
Powiązania:
https://bibliotekanauki.pl/articles/333487.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
zakłócenia impulsowe
filtr miriadowy
filtr medianowy
tętno płodu
linia odniesienia tętna płodu
impulsive noise
myriad filter
meridian filter
fetal heart rate
FHR baseline
Opis:
This paper addresses the problem of impulsive noise cancellation in digital signal area. The myriad and meridian filters are the type of robust filters which are very useful in suppressing the impulsive type of noise. The cost functions of theses filters have very similar structure. In this paper the generalized filter based on Lp norm is presented. The proposed filter operates in a wide range of impulsive noise due to the proper adjustment of p in the Lp norm. The presented filter is applied to suppress an impulsive noise in fetal heart rate (FHR) signal. Simulation results confirm the validity of the proposed filter.
Źródło:
Journal of Medical Informatics & Technologies; 2011, 17; 73-79
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coincidence of maternal and fetal QRS complexes in view of fetal heart rate determination
Autorzy:
Kupka, T.
Jeżewski, J.
Matonia, A.
Wróbel, J.
Horoba, K.
Powiązania:
https://bibliotekanauki.pl/articles/333792.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
brzuszne EKG płodu
monitorowanie płodu
tętno płodu
abdominal fetal electrocardiogram
fetal monitoring
fetal heart rate
Opis:
Indirect fetal electrocardiography is a developing diagnostic method in perinatal medicine. Signals of electrical activity being recorded from maternal abdomen surface contain more information than in till now used method of mechanical heart activity measurement based on ultrasound signals. The main problem relies on separation of basic useful component from a signal containing also dominant maternal electrocardiogram and muscles activity artifacts. The algorithms of maternal electrocardiogram suppression via subtraction are commonly used. Although regarding their complexity, these algorithms have limited applicability in systems for long-term monitoring of fetal heart activity. Other solution relies on simple blanking of maternal QRS complexes. However, in case of coincidence of fetal and maternal QRS complexes, this leads to partial loss of information about fetal heart rate variability. For evaluation of how often such coincidence of both complexes takes place, the algorithm has been developed which is described in this paper.
Źródło:
Journal of Medical Informatics & Technologies; 2002, 4; MT49-55
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving the periodicity measurement in fetal heart activity signal
Autorzy:
Roj, D.
Wróbel, J.
Horoba, K.
Przybyła, T.
Kupka, T.
Powiązania:
https://bibliotekanauki.pl/articles/332933.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
monitorowanie płodu
tętno płodu
USG metodą Dopplera
fetal monitoring
fetal heart rate
ultrasound Doppler
Opis:
In this paper we discussed the influence of preliminary processing of the ultrasound Doppler signal on accuracy of the fetal heart rate estimation as well as on reliability of the FHR instantaneous variability assessment. We attempted to develop an optimal processing channel of US Doppler signal in order to measure the periodicity of fetal heart activity with accuracy as close as possible to that ensured by FECG. The FHR values determined from the US signal were compared to the reference data obtained from direct FECG. In a final evaluation we used the parameters describing the FHR variability as the clinically important signal features being the most sensitive to any periodicity inaccuracy. The results proved that an application of proposed algorithms improves the accuracy of interval measurements and FHR instantaneous variability assessment in relation to the new-generation fetal monitors.
Źródło:
Journal of Medical Informatics & Technologies; 2010, 16; 19-26
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The prediction of the low fetal birth weight based on quantitative description of cardiotocographic signals
Autorzy:
Czabański, R.
Jeżewski, M.
Wróbel, J.
Kupka, T.
Łęski, J.
Jeżewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/333495.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
weryfikacja podpisu online
programowanie dynamiczne
online signature verification
feature context
dynamic programming
Opis:
Cardiotocography (CTG) is a routine method of fetal condition assessment used in modern obstetrics. It is a biophysical method based on simultaneous recording and analysis of activity of fetal heart, fetal movements and maternal uterine contractions. The fetal condition is diagnosed on the basis of printed CTG trace evaluation. The correct interpretation of CTG traces from a bedside monitor is very difficult even for experienced clinicians. Therefore, computerized fetal monitoring systems are used to yield the quantitative description of the signal. However, the effective methods, aiming to support the conclusion generation, are still being searched. One of the most important features defining the state of fetal outcome is the weight of the newborn. The presented work describes an application of the Artificial Neural Network Based on Logical Interpretation of fuzzy if-then Rules (ANBLIR) to evaluate the risk of the low birth weight using a set of parameters quantitatively describing the CTG traces. The obtained results confirm that the neuro-fuzzy based CTG classification methods are very efficient for the prediction of the fetal outcome.
Źródło:
Journal of Medical Informatics & Technologies; 2008, 12; 97-102
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of gestational age on neural networks interpretation of fetal monitoring signals
Autorzy:
Jeżewski, M.
Czabański, R.
Horoba, K.
Wróbel, J.
Łęski, J.
Jeżewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/333505.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
monitoring płodu
kardiotokografia
klasyfikacja
sieci neuronowe
fetal monitoring
cardiotocography
classification
neural networks (NN)
Opis:
Cardiotocographic monitoring (CTG) is a primary biophysical monitoring method for assessment of the fetal state and is based on analysis of fetal heart rate, uterine contraction activity and fetal movement signals. Visual analysis of CTG traces is very difficult so computer-aided fetal monitoring systems have become a standard in clinical centres. We proposed the application of neural networks for the prediction of fetal outcome using the parameters of quantitative description of acquired signals as inputs. We focused on the influence of the gestational age (during trace recording) on the fetal outcome classification quality. We designed MLP and RBF neural networks with changing the number of neurons in the hidden layer to find the best structure. Networks were trained and tested fifty times, with random cases assignment to training, validating and testing subset. We obtained the value of sensitivity index above 0.7, what may be regarded as good result. However additional trace grouping within similar gestational age, increased classification quality in the case of MLP networks.
Źródło:
Journal of Medical Informatics & Technologies; 2008, 12; 137-142
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel approach to comparison of the fetal heart rate baseline estimation algorithms
Autorzy:
Jezewski, J.
Horoba, K.
Roj, D.
Wrobel, J.
Kupka, T.
Matonia, A.
Powiązania:
https://bibliotekanauki.pl/articles/332862.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
fetal monitoring
baseline estimation
acceleration
deceleration
monitorowanie płodu
estymacja
przyspieszanie
zwalnianie
Opis:
A number of algorithms for estimating the so called fetal heart rate baseline was proposed so far. However, there is no reference pattern enabling their objective evaluation, and thus no methodology of comparing the competing algorithms still exists. In this paper we propose a method for evaluation of automatically determined baseline in reference to a group of experts, basing on ten separate groups of signals comprising typical patterns observed in the fetal heart rate. For the purpose of quantitative assessment of the estimated baseline a new synthetic inconsistency coefficient is presented. The proposed methodology was applied to evaluate ten well-known algorithms. We believe that the method will be a valuable tool for assessment of the existing algorithms, as well as for developing new ones.
Źródło:
Journal of Medical Informatics & Technologies; 2015, 24; 231-238
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł

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