Waldemar Wójcik

Prof. Dr. Waldemar Wójcik

Department of Electronics and Information Technology, Faculty of Electrical Engineering and Computer Science, Lublin University Technology, Nadbystrzycka 38A, PL-20618 Lublin, Poland
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Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 February 2021 in Sensors
Verified
Journal Article
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Oleg AvruninOleg Avrunin
Oleg Avrunin
YNYana Nosova
Yana Nosova
Abdelhamid Ibrahim YounoussAbdelhamid Ibrahim Younouss
Abdelhamid Ibrahim Younouss
SPSergii Pavlov
Sergii Pavlov
NSNatalia O. Shushliapina
Natalia O. Shushliapina
AKAliya Kalizhanova
Aliya Kalizhanova
Individual anatomical features of the paranasal sinuses and dentoalveolar system, the complexity of physiological and pathophysiological processes in this area, and the absence of actual standards of the norm and typical pathologies lead to the fact that differential diagnosis and assessment of the severity of the course of odontogenic sinusitis significantly depend on the measurement methods of significant indicators and have significant variability. Therefore, an urgent task is to expand the diagnostic capabilities of existing research methods, study the significance of the measured indicators, and substantiate the expediency of their use in the diagnosis of specific pathologies in an automated mode. Methods of digital filtering, image segmentation and analysis, fluid dynamics, and statistical and discriminant analysis were used. Preliminary differential diagnosis of odontogenic sinusitis can be performed by densitemetric analysis of tomographic images of the maxillary sinuses, performed using frontal multiplanar reconstructions according to a given algorithm. The very manifestation of the characteristic changes in the densitography of the maxillary sinus allows for the initiation of certain pathological processes and permits the development of the effectiveness of the diagnosis of the pathology of the sinus sinuses, which can be realized automatically in real life.

9 April 2012 in Experimental Thermal and Fluid Science
Verified
Journal Article
Closed access
Andrzej SmolarzAndrzej Smolarz
Andrzej Smolarz
AKAndrzej Kotyra
Andrzej Kotyra
WWWaldemar Wójcik
Waldemar Wójcik
JBJavier Ballester
Javier Ballester

WWWaldemar Wójcik
Waldemar Wójcik
IMIryna Mezhiievska
Iryna Mezhiievska
SPSergii Pavlov
Sergii Pavlov
TLTomasz Tomasz Lewandowski
Tomasz Tomasz Lewandowski
OVOleh Vlasenko
Oleh Vlasenko
ALAnna Lewandowska
Anna Lewandowska
Background: Today, cardiovascular diseases cause 47% of all deaths among the European population, which is 4 million cases every year. In Ukraine, CAD accounts for 65% of the mortality rate from circulatory system diseases of the able-bodied population and is the main cause of disability. The aim of this study is to develop a medical expert system based on fuzzy sets for assessing the degree of coronary artery lesions in patients with coronary artery disease. Methods: The method of using fuzzy sets for the implementation of an information expert system for solving the problems of medical diagnostics, in particular, when assessing the degree of anatomical lesion of the coronary arteries in patients with various forms of coronary artery disease, has been developed. Results: The paper analyses the main areas of application of mathematical methods in medical diagnostics, and formulates the principles of diagnostics, based on fuzzy logic. The developed models and algorithms of medical diagnostics are based on the ideas and principles of artificial intelligence and knowledge engineering, the theory of experiment planning, the theory of fuzzy sets and linguistic variables. The expert system is tested on real data. Through research and comparison of the results of experts and the created medical expert system, the reliability of supporting the correct decision making of the medical expert system based on fuzzy sets for assessing the degree of anatomical lesion of the coronary arteries in patients with various forms of coronary artery disease with the assessment of experts was 95%, which shows the high efficiency of decision making. Conclusions: The practical value of the work lies in the possibility of using the automated expert system for the solution of the problems of medical diagnosis based on fuzzy logic for assessing the degree of anatomical lesion of the coronary arteries in patients with various forms of coronary artery disease. The proposed concept must be further validated for inter-rater consistency and reliability. Thus, it is promising to create expert medical systems based on fuzzy sets for assessing the degree of disease pathology.

29 February 2024 in Sensors
Verified
Journal Article
Open access
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WWWaldemar Wójcik
Waldemar Wójcik
ZHZhengbing Hu
Zhengbing Hu
YUYuriy Ushenko
Yuriy Ushenko
Andrzej SmolarzAndrzej Smolarz
Andrzej Smolarz
ISIryna Soltys
Iryna Soltys
ZAZhalau Aitkulov
Zhalau Aitkulov
Our work uses a polarization matrix formalism to analyze and algorithmically represent optical anisotropy by open dehydration of blood plasma films. Analytical relations for Jones matrix reconstruction of optical birefringence maps of protein crystal networks of dehydrated biofluid films are found. A technique for 3D step-by-step measurement of the distributions of the elements of the Jones matrix or Jones matrix images (JMI) of the optically birefringent structure of blood plasma films (BPF) has been created. Correlation between JMI maps and corresponding birefringence images of dehydrated BPF and saliva films (SF) obtained from donors and prostate cancer patients was determined. Within the framework of statistical analysis of layer-by-layer optical birefringence maps, the parameters most sensitive to pathological changes in the structure of dehydrated films were found to be the central statistical moments of the 1st to 4th orders. We physically substantiated and experimentally determined the sensitivity of the method of 3D polarization scanning technique of BPF and SF preparations in the diagnosis of endometriosis of uterine tissue.

1 January 2012 in BioMedical Engineering OnLine
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Robert KoprowskiRobert Koprowski
Robert Koprowski
WZWitold Zieleźnik
Witold Zieleźnik
ZWZygmunt Wrobel
Zygmunt Wrobel
JMJustyna Małyszek-Tumidajewicz
Justyna Małyszek-Tumidajewicz
BSBeata Stępień
Beata Stępień
WWWaldemar Wójcik
Waldemar Wójcik
This paper concerns the analysis of the features obtained from thyroid ultrasound images in left and right transverse and longitudinal sections. In the image analysis, the thyroid lobe is treated as a texture for healthy subjects and patients with Hashimoto’s disease. The applied methods of analysis and image processing were profiled to obtain 10 features of the image. Then, their significance in the classification was shown. In this study, the examined group consisted of 29 healthy subjects aged 18 to 60 and 65 patients with Hashimoto's disease. For each subject, four ultrasound images were taken. They were all in transverse and longitudinal sections of the right and left lobe of the thyroid, which gave 376 images in total. 10 different features obtained from each ultrasound image were suggested. The analyzed thyroid lobe was marked automatically or manually with a rectangular element. The analysis of 10 features and the creation for each one of them their own decision tree configuration resulted in distinguishing 3 most significant features. The results of the quality of classification show accuracy above 94% for a non-trimmed decision tree.

1 January 2012 in BioMedical Engineering OnLine
Verified
Journal Article
Open access
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Robert KoprowskiRobert Koprowski
Robert Koprowski
AKANNA KORZYNSKA
ANNA KORZYNSKA
ZWZygmunt Wrobel
Zygmunt Wrobel
WZWitold Zieleźnik
Witold Zieleźnik
AWAgnieszka Witkowska
Agnieszka Witkowska
WWWaldemar Wójcik
Waldemar Wójcik
This paper shows the influence of a measurement method of features in the diagnosis of Hashimoto’s disease. Sensitivity of the algorithm to changes in the parameters of the ROI, namely shift, resizing and rotation, has been presented. The obtained results were also compared to the methods known from the literature in which decision trees or average gray level thresholding are used. In the study, 288 images obtained from patients with Hashimoto’s disease and 236 images from healthy subjects have been analyzed. For each person, an ultrasound examination of the left and right thyroid lobe in transverse and longitudinal sections has been performed. With the use of the developed algorithm, a discriminant analysis has been conducted for the following five options: linear, diaglinear, quadratic, diagquadratic and mahalanobis. The left and right thyroid lobes have been analyzed both together and separately in transverse and longitudinal sections. In addition, the algorithm enabled to analyze specificity and sensitivity as well as the impact of sensitivity of ROI shift, repositioning and rotation on the measured features. The analysis has shown that the highest accuracy was obtained for the longitudinal section (LD) with the method of linear, yielding sensitivity = 76%, specificity = 95% and accuracy ACC = 84%. The conducted sensitivity assessment confirms that changes in the position and size of the ROI have little effect on sensitivity and specificity. The analysis of all cases, that is, images of the left and right thyroid lobes in transverse and longitudinal sections, has shown specificity ranging from 60% to 95% and sensitivity from 62% to 89%. Additionally, it was shown that the value of ACC for the method using decision trees as a classifier is equal to 84% for the analyzed data. Thresholding of average brightness of the ROI gave ACC equal to 76%.