Institute of Fundamental Technological Research
Polish Academy of Sciences

Staff

Agnieszka Pręgowska, PhD

Department of Information and Computational Science (ZIiNO)
Research Group for Neuroinformatics (ZeBNI)
position: assistant professor
telephone: (+48) 22 826 12 81 ext.: 417
room: 442
e-mail:

Doctoral thesis
2013-06-05 Półaktywne sterowanie układami mechanicznymi drgającymi skrętnie 
supervisor -- Prof. Tomasz Szolc, PhD, DSc, prof. IPPT
 

Recent publications
1.  Pręgowska A., Signal fluctuations and the information transmission rates in binary communication channels, Entropy, ISSN: 1099-4300, DOI: 10.3390/e23010092, Vol.23, No.1, pp.92-1-12, 2021

Abstract:
In the nervous system, information is conveyed by sequence of action potentials, called spikes-trains. As MacKay and McCulloch suggested, spike-trains can be represented as bits sequences coming from Information Sources (IS). Previously, we studied relations between spikes' Information Transmission Rates (ITR) and their correlations, and frequencies. Now, I concentrate on the problem of how spikes fluctuations affect ITR. The IS are typically modeled as stationary stochastic processes, which I consider here as two-state Markov processes. As a spike-trains' fluctuation measure, I assume the standard deviation σ, which measures the average fluctuation of spikes around the average spike frequency. I found that the character of ITR and signal fluctuations relation strongly depends on the parameter s being a sum of transitions probabilities from a no spike state to spike state. The estimate of the Information Transmission Rate was found by expressions depending on the values of signal fluctuations and parameter s. It turned out that for smaller s<1, the quotient ITR/σ has a maximum and can tend to zero depending on transition probabilities, while for 1

Keywords:
information source, information transmission rate, fluctuations, Shannon entropy, spike-trains, standard deviation

Affiliations:
Pręgowska A. - IPPT PAN
2.  Garlinska M., Pręgowska A., Gutowska I., Osial M., Szczepański J., Experimental study of the free space optics communication system operating in the 8–12 μm spectral range, Electronics , ISSN: 2079-9292, DOI: 10.3390/electronics10080875, Vol.10, No.8, pp.875-1-13, 2021

Abstract:
(1) Background: Free space optics communication (FSO) has improved wireless communication and data transfer thanks to high bandwidth, low power consumption, energy efficiency, a high transfer capacity, and a wide applicability field. The FSO systems also have their limitations, including weather conditions and obstacles in the way of transmission. (2) Methods: This research assesses the atmospheric conditions’ influence on the intensity of received radiation, both experimentally and theoretically. The construction of a laboratory test stand of the FSO system, which is operating in the third-atmosphere transmission window (8–12 μm), is proposed. Next, considering different atmospheric conditions, the experimental validation was conducted, both in a laboratory and real conditions. (3) Results: The measurements were carried out for two optical links working with wavelengths of 1.5 μm and 10 μm. It was found that optical radiation with a wavelength of about 10 μm is characterized by better transmission properties in the case of limited visibility (e.g.,light rain and fogs) than in the case of near-infrared waves. The same conclusion was found in analytical investigations. (4) Conclusions: The results obtained show that optical radiation with a wavelength of about 10 μm in limited visibility is characterized by better transmission properties than near-infrared waves. This demonstrates the validity of designing FSO links operating in the range 8–12 μm band, e.g., based on quantum cascade lasers and HgCdTe photodiodes.

Keywords:
free space optical communication, IR photodetector, quantum cascade laser, wireless communication

Affiliations:
Garlinska M. - National Center for Research and Development (PL)
Pręgowska A. - IPPT PAN
Gutowska I. - Oregon State University (US)
Osial M. - University of Warsaw (PL)
Szczepański J. - IPPT PAN
3.  Pręgowska A., Masztalerz K., Garlińska M., Osial M., A worldwide journey through distance education-from the post office to virtual, augmented and mixed realities, and education during the COVID-19 pandemic, Education Sciences, ISSN: 2227-7102, DOI: 10.3390/educsci11030118, Vol.11, No.3, pp.118-1-26, 2021

Abstract:
Surprisingly, distance education is quite an old concept. Its origins date back to the first correspondence-based course, which took place via the postal service in Boston, USA, in the 18th century. Rapid technological developments, especially in video and audio streaming, have increased the availability of such courses and moved learning into the virtual world. Due to the ongoing COVID-19 pandemic, we are witnessing an accelerated revolution in the learning process, as nearly all forms of education have been shifted online. Will this have a destructive effect on the human psyche? Is humanity sufficiently aware and ready for such a dramatic change? Will we return to physical in-classroom studies, or is remote distance education set to become the new norm? In particular, in medicine, computer science, fine arts, or architectural design, such a rapid change in the way students learn can be quite challenging. In this paper, we provide an overview of the history of distance learning, taking into account teachers’ and students’ points of view in both secondary and higher education.

Keywords:
distance learning, distance education, online courses

Affiliations:
Pręgowska A. - IPPT PAN
Masztalerz K. - other affiliation
Garlińska M. - other affiliation
Osial M. - University of Warsaw (PL)
4.  Paprocki B., Pręgowska A., Szczepański J., Optimizing information processing in brain-inspired neural networks, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2020.131844, Vol.68, No.2, pp.225-233, 2020

Abstract:
The way brain networks maintain high transmission efficiency is believed to be fundamental in understanding brain activity. Brains consisting of more cells render information transmission more reliable and robust to noise. On the other hand, processing information in larger networks requires additional energy. Recent studies suggest that it is complexity, connectivity, and function diversity, rather than just size and the number of neurons, that could favour the evolution of memory, learning, and higher cognition. In this paper, we use Shannon information theory to address transmission efficiency quantitatively. We describe neural networks as communication channels, and then we measure information as mutual information between stimuli and network responses. We employ a probabilistic neuron model based on the approach proposed by Levy and Baxter, which comprises essential qualitative information transfer mechanisms. In this paper, we overview and discuss our previous quantitative results regarding brain-inspired networks, addressing their qualitative consequences in the context of broader literature. It is shown that mutual information is often maximized in a very noisy environment e.g., where only one-third of all input spikes are allowed to pass through noisy synapses and farther into the network. Moreover, we show that inhibitory connections as well as properly displaced long-range connections often significantly improve transmission efficiency. A deep understanding of brain processes in terms of advanced mathematical science plays an important role in the explanation of the nature of brain efficiency. Our results confirm that basic brain components that appear during the evolution process arise to optimise transmission performance.

Keywords:
neural network, entropy, mutual information, noise, inhibitory neuron

Affiliations:
Paprocki B. - Kazimierz Wielki University (PL)
Pręgowska A. - IPPT PAN
Szczepański J. - IPPT PAN
5.  Proniewska K., Pręgowska A., Malinowski P., Identification of human vital functions directly relevant to the respiratory system based on the cardiac and acoustic parameters and random forest, IRBM, ISSN: 1959-0318, DOI: 10.1016/j.irbm.2020.02.006, pp.1-6, 2020

Abstract:
Regarding sleep research, polysomnography (PSG) also called a sleep study, is a gold standard. It incorporates brain waves, the oxygen level in the blood, heart rate and breathing, and leg movement recordings. PSG is a complicated and expensive laboratory-based procedure, usually done in hospitals or special sleep center. In this study, an alternative technique for Sleep-Related Breathing Disorders (SRBD) based on selected cardiac and acoustic parameters and the Random Forest (RF) has been studied. A system dedicated to the detection of simultaneously acquired ECG and acoustic signals, which are collected during sleep at home environment is proposed. Results obtained indicate that classification and regression tree models such as RF are appropriate for the evaluation of sleep disorders like SRBD. The best identification of sleep irregularities at level 89.00 percent for the raw database was obtained. Thus, statistical predictive models allow identification of breathing events with high levels of sensitivity and specificity, providing an inexpensive and accurate diagnosis.

Keywords:
patient monitoring, random forest, disorders, biomarkers

Affiliations:
Proniewska K. - Jagiellonian University (PL)
Pręgowska A. - IPPT PAN
Malinowski P. - other affiliation
6.  Proniewska K., Pręgowska A., Dołęga-Dołęgowski D., Dudek D., Immersive technologies as a solution for general data protection regulation in Europe and impact on the COVID-19 pandemic, Cardiology Journal, ISSN: 1897-5593, DOI: 10.5603/CJ.a2020.0102, pp.1-21, 2020

Abstract:
Background: General data protection regulation (GDPR) provides rules according to which data should be managed and processed in a secure and appropriate way for patient requirements and security. Currently, everyone in Europe is covered by GDPR. Thus, the medical practice also requires access to patient data in a safe and secure way. Methods: Holographic technology allows users to see everything visible ona computer screen in a new and less restricted way, i. e. without the limitations of traditional computers and screens. Results: In this study, a three-dimensional holographic doctors' assistant is designed and implemented in a way that meets the GDPR requirements. The HoloView application, which is tailored to run on Microsoft HoloLens, is proposed toallow display and access to personal data and so-called sensitive information of all individual patients without the risk that it will be presented to unauthorized persons. Conclusions: To enhance the user experience and remain consistent with GSPR, a holographic desk is proposed that allows displaying patient data and sensitive information only in front of the doctor's eyes using mixed reality glasses. Last but not least, it boasts of a reduction in infection risk for the staff during the COVID-19 pandemic, affording medical care to be carried out by as few doctors as possible.

Keywords:
augmented reality, mixed reality, pandemic

Affiliations:
Proniewska K. - Jagiellonian University (PL)
Pręgowska A. - IPPT PAN
Dołęga-Dołęgowski D. - Jagiellonian University (PL)
Dudek D. - Jagiellonian University (PL)
7.  Garlinska M., Pręgowska A., Masztalerz K., Osial M., From mirrors to free-space optical communication-historical aspects in data transmission, Future Internet, ISSN: 1999-5903, DOI: 10.3390/fi12110179, Vol.12, No.11, pp.179-1-18, 2020

Abstract:
Fast communication is of high importance. Recently, increased data demand and crowded radio frequency spectrum have become crucial issues. Free-Space Optical Communication (FSOC) has diametrically changed the way people exchange information. As an alternative to wire communication systems, it allows efficient voice, video, and data transmission using a medium like air. Due to its large bandwidth, FSOC can be used in various applications and has therefore become an important part of our everyday life. The main advantages of FSOC are a high speed, cost savings, compact structures, low power, energy efficiency, a maximal transfer capacity, and applicability. The rapid development of the high-speed connection technology allows one to reduce the repair downtime and gives the ability to quickly establish a backup network in an emergency. Unfortunately, FSOC is susceptible to disruption due to atmospheric conditions or direct sunlight. Here, we briefly discuss Free-Space Optical Communication from mirrors and optical telegraphs to modern wireless systems and outline the future development directions of optical communication.

Keywords:
free-space optical communication, telecommunications, wireless communication, data transfer history, communication networks

Affiliations:
Garlinska M. - National Center for Research and Development (PL)
Pręgowska A. - IPPT PAN
Masztalerz K. - other affiliation
Osial M. - University of Warsaw (PL)
8.  Proniewska K., Pręgowska A., Walecki P., Dołęga-Dołęgowski D., Ferrari R., Dudek D., Overview of the holographic-guided cardiovascular interventions and training - a perspective, Bio-Algorithms and Med-Systems, ISSN: 1895-9091, DOI: 10.1515/bams-2020-0043, Vol.16, No.3, pp.20200043-1-9, 2020

Abstract:
Immersive technologies, like Virtual Reality (VR), Augmented Reality (AR) and Mixed Reality (MR) have undergone technical evolutions over the last few decades. Their rapid development and dynamic changes enable their effective applications in medicine, in fields like imaging, preprocedural planning, treatment, operations planning, medical students training, and active support during therapeutic and rehabilitation procedures. Within this paper, a comprehensive analysis of VR/AR/MR application in the medical industry and education is presented. We overview and discuss our previous experience with AR/MR and 3D visual environment and MR-based imaging systems in cardiology and interventional cardiology. Our research shows that using immersive technologies users can not only visualize the heart and its structure but also obtain quantitative feedback on their location. The MR-based imaging system proposed offers better visualization to interventionists and potentially helps users understand complex operational cases. The results obtained suggest that technology using VR/AR/MR can be successfully used in the teaching process of future doctors, both in aspects related to anatomy and clinical classes. Moreover, the system proposed provides a unique opportunity to break the boundaries, interact in the learning process, and exchange experiences inside the medical community.

Keywords:
augmented reality, improving the education process, interaction, intraprocedural visualization, mixed reality, preprocedural planning, teaching

Affiliations:
Proniewska K. - Jagiellonian University (PL)
Pręgowska A. - IPPT PAN
Walecki P. - other affiliation
Dołęga-Dołęgowski D. - Jagiellonian University (PL)
Ferrari R. - other affiliation
Dudek D. - Jagiellonian University (PL)
9.  Pręgowska A., Kaplan E., Szczepański J., How far can neural correlations reduce uncertainty? Comparison of information transmission rates for Markov and Bernoulli processes, International Journal of Neural Systems, ISSN: 0129-0657, DOI: 10.1142/S0129065719500035, Vol.29, No.8, pp.1950003-1-13, 2019

Abstract:
The nature of neural codes is central to neuroscience. Do neurons encode information through relatively slow changes in the firing rates of individual spikes (rate code) or by the precise timing of every spike (temporal code)? Here we compare the loss of information due to correlations for these two possible neural codes. The essence of Shannon's definition of information is to combine information with uncertainty: the higher the uncertainty of a given event, the more information is conveyed by that event. Correlations can reduce uncertainty or the amount of information, but by how much? In this paper we address this question by a direct comparison of the information per symbol conveyed by the words coming from a binary Markov source (temporal code) with the information per symbol coming from the corresponding Bernoulli source (uncorrelated, rate code). In a previous paper we found that a crucial role in the relation between information transmission rates (ITRs) and firing rates is played by a parameter s, which is the sum of transition probabilities from the no-spike state to the spike state and vice versa. We found that in this case too a crucial role is played by the same parameter s. We calculated the maximal and minimal bounds of the quotient of ITRs for these sources. Next, making use of the entropy grouping axiom, we determined the loss of information in a Markov source compared with the information in the corresponding Bernoulli source for a given word length. Our results show that in the case of correlated signals the loss of information is relatively small, and thus temporal codes, which are more energetically efficient, can replace rate codes effectively. These results were confirmed by experiments.

Keywords:
Shannon information theory, information source, information transmission rate, firing rate, neural coding

Affiliations:
Pręgowska A. - IPPT PAN
Kaplan E. - Icahn School of Medicine at Mount Sinai (US)
Szczepański J. - IPPT PAN
10.  Pręgowska A., Proniewska K., van Dam P., Szczepański J., Using Lempel-Ziv complexity as effective classification tool of the sleep-related breathing disorders, Computer Methods and Programs in Biomedicine, ISSN: 0169-2607, DOI: 10.1016/j.cmpb.2019.105052, Vol.182, pp.105052-1-7, 2019

Abstract:
Background and objective: People suffer from sleep disorders caused by work-related stress, irregular lifestyle or mental health problems. Therefore, development of effective tools to diagnose sleep disorders is important. Recently, to analyze biomedical signals Information Theory is exploited. We propose efficient classification method of sleep anomalies by applying entropy estimating algorithms to encoded ECGs signals coming from patients suffering from Sleep-Related Breathing Disorders (SRBD). Methods: First, ECGs were discretized using the encoding method which captures the biosignals variability. It takes into account oscillations of ECG measurements around signals averages. Next, to estimate entropy of encoded signals Lempel–Ziv complexity algorithm (LZ) which measures patterns generation rate was applied. Then, optimal encoding parameters, which allow distinguishing normal versus abnormal events during sleep with high sensitivity and specificity were determined numerically. Simultaneously, subjects' states were identified using acoustic signal of breathing recorded in the same period during sleep. Results: Random sequences show normalized LZ close to 1 while for more regular sequences it is closer to 0. Our calculations show that SRBDs have normalized LZ around 0.32 (on average), while control group has complexity around 0.85. The results obtained to public database are similar, i.e. LZ for SRBDs around 0.48 and for control group 0.7. These show that signals within the control group are more random whereas for the SRBD group ECGs are more deterministic. This finding remained valid for both signals acquired during the whole duration of experiment, and when shorter time intervals were considered. Proposed classifier provided sleep disorders diagnostics with a sensitivity of 93.75 and specificity of 73.00%. To validate our method we have considered also different variants as a training and as testing sets. In all cases, the optimal encoding parameter, sensitivity and specificity values were similar to our results above. Conclusions: Our pilot study suggests that LZ based algorithm could be used as a clinical tool to classify sleep disorders since the LZ complexities for SRBD positives versus healthy individuals show a significant difference. Moreover, normalized LZ complexity changes are related to the snoring level. This study also indicates that LZ technique is able to detect sleep abnormalities in early disorders stage.

Keywords:
information theory, Lempel-Ziv complexity, entropy, ECG, sleep-related breathing disorders, randomness

Affiliations:
Pręgowska A. - IPPT PAN
Proniewska K. - Jagiellonian University (PL)
van Dam P. - PEACS BV, Nieuwerbrug (NL)
Szczepański J. - IPPT PAN
11.  Błoński S., Pręgowska A., Michałek T., Szczepański J., The use of Lempel-Ziv complexity to analyze turbulence and flow randomness based on velocity fluctuations, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2019.130876, Vol.67, No.5, pp.957-962, 2019

Abstract:
One of the mathematical tools to measure the generation rate of new patterns along a sequence of symbols is the Lempel-Ziv complexity (LZ). Under additional assumptions, LZ is an estimator of entropy in the Shannon sense. Since entropy is considered as a measure of randomness, this means that LZ can be treated also as a randomness indicator. In this paper, we used LZ concept to the analysis of different flow regimes in cold flow combustor models. Experimental data for two combustor's configurations motivated by efficient mixing need were considered. Extensive computer analysis was applied to develop a complexity approach to the analysis of velocity fluctuations recorded with hot-wire anemometry and PIV technique. A natural encoding method to address these velocity fluctuations was proposed. It turned out, that with this encoding the complexity values of the sequences are well correlated with the values obtained by means of RMS method (larger/smaller complexity larger/smaller RMS). However, our calculations pointed out the interesting result that most complex, this means most random, behavior does not overlap with the "most turbulent" point determined by the RMS method, but it is located in the point with maximal average velocity. It seems that complexity method can be particularly useful to analyze turbulent and unsteady flow regimes. Moreover, the complexity can also be used to establish other flow characteristics like its ergodicity or mixing.

Keywords:
turbulence, complexity, entropy, randomness

Affiliations:
Błoński S. - IPPT PAN
Pręgowska A. - IPPT PAN
Michałek T. - IPPT PAN
Szczepański J. - IPPT PAN
12.  Pręgowska A., Casti A., Kaplan E., Wajnryb E., Szczepański J., Information processing in the LGN: a comparison of neural codes and cell types, BIOLOGICAL CYBERNETICS, ISSN: 0340-1200, DOI: 10.1007/s00422-019-00801-0, Vol.113, No.4, pp.453-464, 2019

Abstract:
To understand how anatomy and physiology allow an organism to perform its function, it is important to know how information that is transmitted by spikes in the brain is received and encoded. A natural question is whether the spike rate alone encodes the information about a stimulus (rate code), or additional information is contained in the temporal pattern of the spikes (temporal code). Here we address this question using data from the cat Lateral Geniculate Nucleus (LGN), which is the visual portion of the thalamus, through which visual information from the retina is communicated to the visual cortex. We analyzed the responses of LGN neurons to spatially homogeneous spots of various sizes with temporally random luminance modulation. We compared the Firing Rate with the Shannon Information Transmission Rate, which quantifies the information contained in the temporal relationships between spikes. We found that the behavior of these two rates can differ quantitatively. This suggests that the energy used for spiking does not translate directly into the information to be transmitted. We also compared Firing Rates with Information Rates for X-ON and X-OFF cells. We found that, for X-ON cells the Firing Rate and Information Rate often behave in a completely different way, while for X-OFF cells these rates are much more highly correlated. Our results suggest that for X-ON cells a more efficient "temporal code" is employed, while for X-OFF cells a straightforward "rate code" is used, which is more reliable and is correlated with energy consumption.
Z rosnącym zapotrzebowaniem na niezawodne, a jednocześnie zapewniające dużą wydajność, narzędzia do skrawania i obróbki plastycznej, coraz większego znaczenia nabiera rozszerzająca się grupa supertwardych ceramik przewodzących prąd. Mate-riały te dobrze rokują w związku z rozwiązaniem problemów tradycyjnych materiałów narzędziowych, których niedoskonałości obejmują wysoką cenę (azotek krzemu, azotek boru), niezdolność do cięcia stopów żelaza w wyniku reakcji chemicznych (diament), niestabilność w obecności wilgoci (azotek boru) i względnie małą twardość (węglik wolframu). Również rosnący popyt na powłoki ochronne o wysokiej twardości, o dob-rych właściwościach sprężystych i stabilności termicznej powoduje, że badania nad nowymi systemami materiałowymi prowadzone są coraz intensywniej. Pomimo że azotki metali przejściowych są już z powodzeniem stosowane do różnych zadań w prze-myśle samochodowym i lotniczym, poszukiwanie ulepszonych materiałów jest tematem wciąż aktualnym. W pracy przedstawiono badania nad osadzaniem cienkich powłok z nowych supertwardych materiałów (SHM), którymi są borki wolframu. Dodatkowo zbadano wpływ domieszkowania tych materiałów tytanem. Warstwy osadzane były metodą ablacji laserowej PLD. Tarcze do osadzania zsyntetyzowane zostały metodą spiekania plazmowego SPS proszków boru i wolframu o stosunku atomów 4,5 do 1. Osadzane z użyciem lasera warstwy mają skład stechiometryczny podobny do użytych tarcz. W warstwach tych dominuje faza WB3. Badania przeprowadzone z użyciem SEM, XRD i nanoindentacji wykazały, że skład fazowy tarcz jest odwzorowany w war-stwach osadzonych laserem. Wszystkie uzyskane warstwy są bardzo twarde i stabilne termicznie. Warstwy osadzane laserem odznaczają się dużą chropowatością. Domiesz-kowanie tytanem zwiększa ilość fazy WB3 w spiekanych tarczach i osadzanych war-stwach oraz zmniejsza ilość i wielkość naniesionych na powierzchnię cząstek.

Keywords:
Shannon information theory, cat LGN, ON–OFF cells, neural coding, entropy, firing rate

Affiliations:
Pręgowska A. - IPPT PAN
Casti A. - Fairleigh Dickinson University (US)
Kaplan E. - Icahn School of Medicine at Mount Sinai (US)
Wajnryb E. - IPPT PAN
Szczepański J. - IPPT PAN
13.  Kurnyta-Mazurek P., Kurnyta A., Pręgowska A., Kaźmierczak K., Frąś L.J., Application concept of the active magnetic suspension technology in the aircraft engine, Aviation Advances & Maintenance, ISSN: 2543-9456, DOI: 10.2478/afit-2018-0006, Vol.41, No.1, pp.161-193, 2018
14.  Proniewska K., Pręgowska A., Malinowski K.P., Sleep-related breathing biomarkers as a predictor of vital functions, Bio-Algorithms and Med-Systems, ISSN: 1895-9091, DOI: 10.1515/bams-2017-0003, Vol.13, No.1, pp.43-49, 2017

Abstract:
Because an average human spends one third of his life asleep, it is apparent that the quality of sleep has an important impact on the overall quality of life. To properly understand the influence of sleep, it is important to know how to detect its disorders such as snoring, wheezing, or sleep apnea. The aim of this study is to investigate the predictive capability of a dual-modality analysis scheme for methods of sleep-related breathing disorders (SRBDs) using biosignals captured during sleep. Two logistic regressions constructed using backward stepwise regression to minimize the Akaike information criterion were extensively considered. To evaluate classification correctness, receiver operating characteristic (ROC) curves were used. The proposed classification methodology was validated with constructed Random Forests methodology. Breathing sounds and electrocardiograms of 15 study subjects with different degrees of SRBD were captured and analyzed. Our results show that the proposed classification model based on selected parameters for both logistic regressions determine the different types of acoustic events during sleep. The ROC curve indicates that selected parameters can distinguish normal versus abnormal events during sleep with high sensitivity and specificity. The percentage of prediction for defined SRBDs is very high. The initial assumption was that the quality of result is growing with the number of parameters included in the model. The best recognition reached is more than 89% of good predictions. Thus, sleep monitoring of breath leads to the diagnosis of vital function disorders. The proposed methodology helps find a way of snoring rehabilitation, makes decisions concerning future treatment, and has an influence on the sleep quality.

Keywords:
patient monitoring, sleep-related breathing disorders, vital functions

Affiliations:
Proniewska K. - Jagiellonian University (PL)
Pręgowska A. - IPPT PAN
Malinowski K.P. - Institute of Plasma Physics and Laser Microfusion (PL)
15.  Konowrocki R., Szolc T., Pochanke A., Pręgowska A., An influence of the stepping motor control and friction models on precise positioning of the complex mechanical system, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, ISSN: 0888-3270, DOI: 10.1016/j.ymssp.2015.09.030, Vol.70-71, pp.397-413, 2016

Abstract:
This paper aims to investigate, both experimentally and theoretically, the electromechanical dynamic interaction between a driving stepping motor and a driven laboratory belt-transporter system. A test-rig imitates the operation of a robotic device in the form of a working tool-carrier under translational motion. The object under consideration is equipped with measurement systems, which enable the registration of electrical and mechanical quantities. Analytical considerations are performed by means of a circuit model of the electric motor and a discrete, non-linear model of the mechanical system. Various scenarios of the working tool-carrier motion and positioning by the belt-transporter are measured and simulated; in all cases the electric current control of the driving motor has been applied. The main goal of this study is to investigate the influence of the stepping motor control parameters along with various mechanical friction models on the precise positioning of a laboratory robotic device.

Keywords:
Belt transporter system, Precise positioning, Stepping motor, Current control, Experimental verification

Affiliations:
Konowrocki R. - IPPT PAN
Szolc T. - IPPT PAN
Pochanke A. - Warsaw University of Technology (PL)
Pręgowska A. - IPPT PAN
16.  Pręgowska A., Szczepański J., Wajnryb E., Temporal code versus rate code for binary Information Sources, NEUROCOMPUTING, ISSN: 0925-2312, DOI: 10.1016/j.neucom.2016.08.034, Vol.216, pp.756-762, 2016

Abstract:
Neuroscientists formulate very different hypotheses about the nature of neural coding. At one extreme, it has been argued that neurons encode information through relatively slow changes in the arrival rates of individual spikes (rate codes) and that the irregularity in the spike trains reflects the noise in the system. At the other extreme, this irregularity is the code itself (temporal codes) so that the precise timing of every spike carries additional information about the input. It is well known that in the estimation of Shannon Information Transmission Rate, the patterns and temporal structures are taken into account, while the “rate code” is already determined by the firing rate, i.e. by the spike frequency. In this paper we compare these two types of codes for binary Information Sources, which model encoded spike trains. Assuming that the information transmitted by a neuron is governed by an uncorrelated stochastic process or by a process with a memory, we compare the Information Transmission Rates carried by such spike trains with their firing rates. Here we show that a crucial role in the relation between information transmission and firing rates is played by a factor that we call the “jumping” parameter. This parameter corresponds to the probability of transitions from the no-spike-state to the spike-state and vice versa. For low jumping parameter values, the quotient of information and firing rates is a monotonically decreasing function of the firing rate, and there therefore a straightforward, one-to-one, relation between temporal and rate codes. However, it turns out that for large enough values of the jumping parameter this quotient is a non-monotonic function of the firing rate and it exhibits a global maximum, so that in this case there is an optimal firing rate. Moreover, there is no one-to-one relation between information and firing rates, so the temporal and rate codes differ qualitatively. This leads to the observation that the behavior of the quotient of information and firing rates for a large jumping parameter value is especially important in the context of bursting phenomena.

Keywords:
Information Theory, Information Source, Stochastic process, Information transmission rate, Firing rate

Affiliations:
Pręgowska A. - IPPT PAN
Szczepański J. - IPPT PAN
Wajnryb E. - IPPT PAN
17.  Konowrocki R., Pręgowska A., Szolc T., Experimental and numerical investigations for the controlled rotary damper dynamically interacting with the electromechanical rotating system, SOLID STATE PHENOMENA, ISSN: 1012-0394, DOI: 10.4028/www.scientific.net/SSP.240.198, Vol.240, pp.198-205, 2016

Abstract:
In the paper dynamic electromechanical coupling between the structural model of the rotating machine drive system and the circuit model of the asynchronous motor has been investigated. By means of the computer model of the rotating machine drive system the results of experimental testing have been confirmed. From the obtained results of computations and measurements it follows that the coupling between the considered rotating system and the installed rotary dampers with the magneto-rheological fluid (MRF) results in effective energy dissipation leading to significant reduction of undesired torsional vibrations.

Keywords:
Electromechanical Coupling, Machine Drive Systems, Rotary MRF Actuator, Torsional Vibrations, Wavelet Transform (WT)

Affiliations:
Konowrocki R. - IPPT PAN
Pręgowska A. - IPPT PAN
Szolc T. - IPPT PAN
18.  Pręgowska A., Szczepański J., Wajnryb E., Mutual information against correlations in binary communication channels, BMC NEUROSCIENCE, ISSN: 1471-2202, DOI: 10.1186/s12868-015-0168-0, Vol.16, No.32, pp.1-7, 2015

Abstract:
Background
Explaining how the brain processing is so fast remains an open problem (van Hemmen JL, Sejnowski T., 2004). Thus, the analysis of neural transmission (Shannon CE, Weaver W., 1963) processes basically focuses on searching for effective encoding and decoding schemes. According to the Shannon fundamental theorem, mutual information plays a crucial role in characterizing the efficiency of communication channels. It is well known that this efficiency is determined by the channel capacity that is already the maximal mutual information between input and output signals. On the other hand, intuitively speaking, when input and output signals are more correlated, the transmission should be more efficient. A natural question arises about the relation between mutual information and correlation. We analyze the relation between these quantities using the binary representation of signals, which is the most common approach taken in studying neuronal processes of the brain.

Results
We present binary communication channels for which mutual information and correlation coefficients behave differently both quantitatively and qualitatively. Despite this difference in behavior, we show that the noncorrelation of binary signals implies their independence, in contrast to the case for general types of signals.

Conclusions
Our research shows that the mutual information cannot be replaced by sheer correlations. Our results indicate that neuronal encoding has more complicated nature which cannot be captured by straightforward correlations between input and output signals once the mutual information takes into account the structure and patterns of the signals.

Keywords:
Shannon information, Communication channel, Entropy, Mutual information, Correlation, Neuronal encoding

Affiliations:
Pręgowska A. - IPPT PAN
Szczepański J. - IPPT PAN
Wajnryb E. - IPPT PAN
19.  Dyniewicz B., Pręgowska A., Bajer C.I., Adaptive control of a rotating system, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, ISSN: 0888-3270, DOI: 10.1016/j.ymssp.2013.09.006, Vol.43, pp.90-102, 2014

Abstract:
In the present paper, an adaptive control of structural vibrations is presented. Based on earlier research, we claim that the periodical switching on of magneto-rheological controlled dampers results in the reduction of the amplitudes of vibrations more than does their permanent actuation. This statement, when applied to a moving load problem, was mathematically proved in earlier papers. In the present paper we determine the efficiency of such a control applied to a rotating shaft. The earlier mathematical analysis allows us to propose a control strategy. A finite element simulation together with the solution of the control problem shows that the dampers should act only during a short period of the highest displacements of the structure. The same conclusion is found in experimental tests. Although high frequency control with MR dampers is less efficient than in the theoretical investigations, we have found an amplitude reduction in the range of 10–20%.

Keywords:
Adaptive control, Semi-active control, Vibration control, Shaft vibrations, Torsional vibrations, Magneto-rheological dampers

Affiliations:
Dyniewicz B. - IPPT PAN
Pręgowska A. - IPPT PAN
Bajer C.I. - IPPT PAN
20.  Szolc T., Konowrocki R., Michajłow M., Pręgowska A., An investigation of the dynamic electromechanical coupling effects in machine drive systems driven by asynchronous motors, MECHANICAL SYSTEMS AND SIGNAL PROCESSING, ISSN: 0888-3270, DOI: 10.1016/j.ymssp.2014.04.004, Vol.49, pp.118-134, 2014

Abstract:
In the paper dynamic electromechanical interaction between the rotating machine drive system and the electric driving motor is considered. The investigations are performed by means of the circuit model of the asynchronous motor as well as using an advanced structural hybrid model of the drive system. Using the analytical solutions applied for the electrical and the mechanical systems the electromagnetic stiffness and coefficient of damping, both generated by the electric motor rotationally interacting with the mechanical system of the given dynamic properties, were determined. By means of experimentally validated computational responses obtained for torsional harmonic excitation induced by the driven machine working tool, a modification of dynamic properties of the mechanical system by the electromagnetic flux between the stator and the rotor has been studied.

Keywords:
Machine drive system, Asynchronous motor, Electromechanical coupling

Affiliations:
Szolc T. - IPPT PAN
Konowrocki R. - IPPT PAN
Michajłow M. - IPPT PAN
Pręgowska A. - IPPT PAN
21.  Pręgowska A., Konowrocki R., Szolc T., Analysis of rotating systems using actuators with magnetorheological fluid to vibration minimization – theoretical and experimental investigation, Symulacja w Badaniach i Rozwoju, ISSN: 2081-6154, Vol.5, No.3, pp.191-198, 2014

Abstract:
The analysis of damped rotating systems using actuators with magnetorheological fluid is the subject of interest. The main purpose of this research is minimization of vibration amplitudes in order to increase fatigue durability of the most responsible machine elements. Here, control damping torques are generated by magnetorheological fluid of adjustable viscosity.
The theoretical investigations are based on a hybrid and finite element structural model (FEM) of the mechanical structure as well as on sensitivity analysis of the response with respect to the actuators damping characteristics. The analysis performed in the paper combines experimental verification using the laboratory test rig with theoretical computations.

Keywords:
rotating systems, torsional vibrations, actuators with a magnetorheological fluid, rotary actuators

Affiliations:
Pręgowska A. - IPPT PAN
Konowrocki R. - IPPT PAN
Szolc T. - IPPT PAN
22.  Pręgowska A., Konowrocki R., Szolc T., On the semi-active control method for torsional vibrations in electro-mechanical systems by means of rotary actuators with a magneto-rheological fluid, JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, Vol.51, No.4, pp.979-992, 2013

Abstract:
The aim of this paper is to present a method of the semi-active control of torsional vibrations in a working machine drive system by means of rotary actuators with a magneto-rheological fluid. The simple open-loop control strategy is proposed for a mechanical system vibrating in steady-state operating conditions. This semi-active control approach is based on the principle of optimum viscous damping and frictional properties realized by the magneto-rheological fluid, where its respective parameters are determined by the applied control electric currents. The analysis is performed theoretically by means of structural electro-mechanical models of the considered drive system as well as experimentally using a laboratory test rig in the form of a rotor-shaft system co-operating with two asynchronous motors generating properly programmed driving and retarding electro-magnetic torques

Keywords:
semi-active control, torsional vibrations, magneto-rheological rotary dampers

Affiliations:
Pręgowska A. - IPPT PAN
Konowrocki R. - IPPT PAN
Szolc T. - IPPT PAN
23.  Pręgowska A., Konowrocki R., Szolc T., Semi-active vibration control using a rotary magnetorheological damper – experimental verification, POMIARY - AUTOMATYKA - ROBOTYKA. PAR, ISSN: 1427-9126, Vol.2, pp.487-491, 2013

Abstract:
From all kinds of vibrations, torsional ones are very important as naturally associated with fundamental rotational drive system motion. The aim of this paper is to present semi-active control of torsional vibrations of the working machine drive systems, which is performed using a rotary damper with the magnetorheological fluid. The main purpose of this research is vibration amplitudes minimization in order to increase fatigue durability of the most responsible machine elements. The special control strategies are proposed for steady-state torsional vibrations suppression. The semi-active control method is based on a principle of determinational optimum current damping coefficient values, which is realized by the magneto-rheological fluid application. The analysis performed in the paper combines experimental verification using the laboratory test rig with theoretical computations. This experiment was designed in the form of the laboratory drive system co-operating with two asynchronous motors generating properly programmed driving and retarding electromagnetic torques.

Keywords:
semi-active control, torsional vibrations, rotary dampers, magnetorheological fluid, electromechanical drive system

Affiliations:
Pręgowska A. - IPPT PAN
Konowrocki R. - IPPT PAN
Szolc T. - IPPT PAN
24.  Pręgowska A., Konowrocki R., Szolc T., Experimental verification of the semi-active control concepts for torsional vibrations of the electro-mechanical system using rotary magneto-rheological actuators, VIBRATIONS IN PHYSICAL SYSTEMS, ISSN: 0860-6897, Vol.25, pp.329-334, 2012

Abstract:
In the paper semi-active control of torsional vibrations of the rotating machine drive system driven by an electric motor is performed by means of rotary actuators with the magneto-rheological fluid. The main purpose of these studies is a minimisation of vibration amplitudes in order to increase the fatigue durability of the most responsible elements, assure possibly precise motion of the driven machine working tool as well as to reduce a generated noise level. For suppression of steady-state torsional vibrations excited by dynamic external torques generated by the motor and by the driven object there are proposed control strategies based on a principle of optimum current damping coefficient values realized by the magneto-rheological fluid. The theoretical control concepts are experimentally verified using the laboratory test rig in the form of drive system co-operating with two asynchronous motors generating properly programmed driving and retarding electromagnetic torques.

Keywords:
semi-active control, torsional vibrations, rotary actuators, magneto-rheological fluid

Affiliations:
Pręgowska A. - IPPT PAN
Konowrocki R. - IPPT PAN
Szolc T. - IPPT PAN

List of recent monographs
1. 
Pręgowska A., Proniewska K., Sleep Disorders - Biostatistical and Information Theory Based Approach, Scholar's Press, pp.1-108, 2018

List of chapters in recent monographs
1. 
Proniewska K., Dołęga-Dołęgowski D., Pręgowska A., Walecki P., Dudek D., Simulations in Medicine, rozdział: Holography as a progressive revolution in medicine, De Gruyter, pp.103-116, 2020
2. 
Pręgowska A., Szolc T., Pochanke A., Konowrocki R., Recent Advances in Automation, Robotics and Measuring Techniques, rozdział: Modeling and dynamic analysis of the precise electromechanical systems driven by the stepping motors, Springer International Publishing, Series: Advances in Intelligent Systems and Computing, 267, Part I, pp.205-215, 2014

Conference papers
1.  Proniewska K., Pręgowska A., Dołęga-Dołegowski D., Chmiel J., Dudek D., Three-dimensional operating room with unlimited perspective, MCSS 2020, 10th International Conference on Multimedia Communications, Services and Security, 2020-10-08/10-09, Kraków (PL), DOI: 10.1007/978-3-030-59000-0_26, Vol.1284, pp.351-361, 2020

Abstract:
Apart fromoperating tables andmodern surgical instruments, themodern operating rooms are equipped with displays and video surveillance systems. The three-dimensional operating room allows users to watch medics perform surgery from different, individually chosen, points of view. For the first time, it is possible to reproduce/repeat the course of the operations and change the perspective or position, fromwhich it is observed. Here, we proposed a solution based on Microsoft HoloLens and Azure Kinect DK devices as remote support to patient management. The operating room is transferred to the digital form in real-time using Augmented Reality based technologies. Users can move around the digital place like a ghost in real space. The approach proposed allows users to see observe surgery from any point of view they want without disturbing the surgeon's workflow. They can change their positions, angle, and place of observation. All environmental restrictions disappear. The presented solution gives trainees a convenient opportunity to learn. It may make a significant contribution to improving the surgeontraining, patients' outcomes, and may allow virtual medical consultations during the surgery between specialists without them leaving their workplace.

Keywords:
3D operating room, augmented reality, HoloLens

Affiliations:
Proniewska K. - Jagiellonian University (PL)
Pręgowska A. - IPPT PAN
Dołęga-Dołegowski D. - Jagiellonian University (PL)
Chmiel J. - other affiliation
Dudek D. - Jagiellonian University (PL)
2.  Konowrocki R., Pochanke A., Pręgowska A., Szolc T., An analysis of precise positioning scenarios of the electromechanical rotating system driven by a stepping motor, SIRM 2015, 11th International Conference on Vibrations in Rotating Machines, 2015-02-23/02-25, Magdeburg (DE), No.ID-40, pp.1-10, 2015

Abstract:
In the paper there is investigated experimentally and theoretically electromechanical dynamic interaction between the driving stepping motor and the driven laboratory belt-transporter system imitating an operation of the robotic device in the form of working tool-carrier under translational motion. The considered object is properly equipped with measurement systems enabling us a registration of studied electrical and mechanical quantities. The analytical considerations are performed by means of the circuit model of the electric motor and of the discrete, non-linear model of the mechanical system. In the investigated examples various scenarios of the working tool-carrier motion and positioning by the belt-transporter are measured and simulated, where in the all cases the electric current control of the driving motor has been applied.

Keywords:
Belt transporter system, Precise positioning, Stepping motor, Current control, Experimental verification

Affiliations:
Konowrocki R. - IPPT PAN
Pochanke A. - Warsaw University of Technology (PL)
Pręgowska A. - IPPT PAN
Szolc T. - IPPT PAN

Conference abstracts
1.  Pręgowska A., Warczak M., Osial M., Superparamagnetyczne nanocząstkina bazie tlenku żelaza domieszkowane terbem i modyfikowane aklarubicynądo magnetycznej hipertermii, XIII Interdyscyplinarna Konferencja Naukowa TYGIEL 2021 „Interdyscyplinarność kluczem do rozwoju”, 2021-03-25/03-28, Lublin (PL), pp.296, 2021
2.  Pręgowska A., Proniewska K., van Dam P., Dudek D., Szczepański J., €žAutomatic arrhythmia detection form two-channel ambulatory ECG recordings using Shannon Information Theory-based algorithms, NFIC, 20th New Frontiers in Interventional Cardiology, 2019-12-11/12-13, Kraków (PL), pp.9, 2019
3.  Proniewska K., Dołęga-Dolegowski D., Pręgowska A., Dudek D., Augmented reality as a doctor support to meet the General Data Protection Regulation in Europe, NFIC, 20th New Frontiers in Interventional Cardiology, 2019-12-11/12-13, Kraków (PL), pp.10, 2019
4.  Proniewska K., Pręgowska A., van Dam P., Szczepański J., Automated ECG and acoustic signal based diagnosis of sleep disorders, NFIC 2018, 19th Interventional Cardiology Workshop New Frontiers in Interventional Cardiology, 2018-12-06/12-06, Kraków (PL), pp.10-11, 2018
5.  Paprocki B., Pręgowska A., Szczepański J., Information Processing in Brain-Inspired Networks: Size and Density Effects, SolMech 2016, 40th Solid Mechanics Conference, 2016-08-29/09-02, Warszawa (PL), No.P192, pp.1-2, 2016
6.  Proniewska K., Pręgowska A., Adaptive design approach to tele-Health trials based on Biostatical and Information Theory methods, Telemedicine and eHealth, 2016-09-02/09-03, Warszawa (PL), pp.1, 2016

Keywords:
adaptive design, biostatistic, information Theory

Affiliations:
Proniewska K. - Jagiellonian University (PL)
Pręgowska A. - IPPT PAN
7.  Proniewska K., Pręgowska A., New approach to quantify breathing pattern changes using a monitoring scoring system, Telemedicine and eHealth, 2016-09-02/09-03, Warszawa (PL), pp.1, 2016

Keywords:
quantify breathing pattern, patient monitoring

Affiliations:
Proniewska K. - Jagiellonian University (PL)
Pręgowska A. - IPPT PAN
8.  Szczepański J., Sanchez-Vives M.V., Arnold M.M., Montejo N., Paprocki B., Pręgowska A., Amigó J.M., Wajnryb E., Analyzing Neuroscience Signals using Information Theory and Complexity Shannon Communication Approach, 12th INCF, 12th INCF Workshop on Node Communication and Collaborative Neuroinformatics, 2015-04-16/04-17, Warszawa (PL), pp.1-32, 2015

Patents
Filing No./Date
Filing Publication
Autors
Title
Protection Area, Applicant Name
Patent Number
Date of Grant
pdf
424702
2018-02-27
BUP 06/2020
2020-03-09
Frąś L.J., Jarząbek D.M., Pręgowska A., Chrzanowska-Giżyńska J.
Przyrząd pomiarowy do mikroskopowej obserwacji i pomiaru deformacji materiałów w czasie rzeczywistym
PL, Instytut Podstawowych Problemów Techniki PAN
235566
WUP 13/2020
2020-09-07



421696
2017-05-24
BUP 25/2018
2018-12-03
Frąś L.J., Kołbuk-Konieczny D., Pręgowska A.
Uchwyt pomiarowy do Dzielonego Pręta Hopkinsona oraz sposób pomiaru zachowania materiału, w którym stosuje się Dzielony Pręt Hopkinsona
PL, Instytut Podstawowych Problemów Techniki PAN
234657
WUP 03/2020
2020-03-31



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