The performance of ECG signals compression is influenced by many things. However, there is not a single study primarily focused on the possible effects of ECG pathologies on the performance of compression algorithms. This study evaluates whether the pathologies present in ECG signals affect the efficiency and quality of compression. Single-cycle fractal-based compression algorithm and compression algorithm based on combination of wavelet transform and set partitioning in hierarchical trees are used to compress 125 15-leads ECG signals from CSE database. Rhythm and morphology of these signals are newly annotated as physiological or pathological. The compression performance results are statistically evaluated. Using both compression algorithms, physiological signals are compressed with better quality than pathological signals according to 8 and 9 out of 12 quality metrics, respectively. Moreover, it was statistically proven that pathological signals were compressed with lower efficiency than physiological signals. Signals with physiological rhythm and physiological morphology were compressed with the best quality. The worst results reported the group of signals with pathological rhythm and pathological morphology. This study is the first one which deals with effects of ECG pathologies on the performance of compression algorithms. Signal-by-signal rhythm and morphology annotations (physiological/pathological) for the CSE database are newly published.
- MeSH
- Algorithms MeSH
- Databases, Factual MeSH
- Electrocardiography methods MeSH
- Fractals MeSH
- Data Compression methods MeSH
- Humans MeSH
- Wavelet Analysis MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The article deals with some basic approaches to the management of secured access to data on external storage devices in real time. Basic steps of effective, safe and easy-to-use handling of personal and/or confidential data are described. Further, a method to protect logins and passwords during their registration into the various applications is presented in the article. Main features of several most commonly used software products are also described considering data protection when used online and stored on various storage devices. The main reasons to apply data protection in the area of medicine and health care services are stated in this article as well.
1st ed. xviii, 401 s.
- Keywords
- Bioinformatika, Multimedia, Data,
- Conspectus
- Lékařské vědy. Lékařství
- NML Fields
- lékařská informatika
Na počátku článku jsou stručně uvedeny anatomické a patologické podklady vzniku chronické venózní insuficience. Blíže jsou rozvedeny patofyziologické konsekvence a jejich vliv na indikace a optimalisaci kompresivní léčby. Probrána je závislost na fyzikálních zákonitostech dle Pascala a Laplace a vliv na Starlingovu rovnováhu. Další podstatný vliv na léčbu má výběr kompresních materiálů a významu indexu tuhosti, včetně dosažených interface tlaků. Širší pozornost je věnována dvou- až čtyřvrstevným kompresním systémům a jejich efektu. Článek je zakončen úvahou o vhodnosti získání více objektivních informací o dosažené kompresi.
The article is introduced with short summary of anatomical and pathological causative data of chronic venous insuficience. Patophysiological consequences and their influence upon indication and optimalisation of compressive treatment are closely discussed. Dependence of physical rules according to that of Pascal and Laplace, and influence to Starling's equation are talked over. Selection of com-pression materials and sense stiffness index (SSI), including reached interface pressure are next factors influencing the treatment. Broadly presented are 2–4 layer compression systems and their effects. Finally, the article suggests need of obtaining further unbiased information on the achieved compression.
- MeSH
- Chronic Disease MeSH
- Lower Extremity pathology MeSH
- Stockings, Compression * MeSH
- Compression Bandages * MeSH
- Humans MeSH
- Varicose Veins pathology MeSH
- Venous Insufficiency * pathology therapy MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
Compression of ECG signal is essential especially in the area of signal transmission in telemedicine. There exist many compression algorithms which are described in various details, tested on various datasets and their performance is expressed by different ways. There is a lack of standardization in this area. This study points out these drawbacks and presents new compression algorithm which is properly described, tested and objectively compared with other authors. This study serves as an example how the standardization should look like. Single-cycle fractal-based (SCyF) compression algorithm is introduced and tested on 4 different databases-CSE database, MIT-BIH arrhythmia database, High-frequency signal and Brno University of Technology ECG quality database (BUT QDB). SCyF algorithm is always compared with well-known algorithm based on wavelet transform and set partitioning in hierarchical trees in terms of efficiency (2 methods) and quality/distortion of the signal after compression (12 methods). Detail analysis of the results is provided. The results of SCyF compression algorithm reach up to avL = 0.4460 bps and PRDN = 2.8236%.
- MeSH
- Algorithms * MeSH
- Databases, Factual * MeSH
- Electrocardiography methods MeSH
- Fractals * MeSH
- Data Compression methods MeSH
- Humans MeSH
- Signal Processing, Computer-Assisted MeSH
- Arrhythmias, Cardiac physiopathology MeSH
- Wavelet Analysis MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Hlavným cieľom práce bolo priblížiť čitateľovi potencionálny efekt využívania kompresného oblečenia (KO) u bežcov. Čitateľovi práce chceme poskytnúť objektívny pohľad na využívanie kompresných podkolienok (KP) a návlekov na trojhlavom svale lýtka v športe. Uvedená práca nie je metaanalýzou, článok poskytuje základné informácie a uvádza čitateľa práce do problematiky využívania KO. V práci sa zameriavame na uvedenie vybraných parametrov, ktoré priamo, resp. nepriamo determinujú výkon a ovplyvňujú schopnosť podať opakovaný výkon. V odbornej literatúre sú v súčasnosti popisované dva účinky (zvýšenie žilného prietoku a redukcia svalových oscilácií), ktoré do výkonu výrazne zasahujú a môžu ho ovplyvňovať. Pri narastajúcej popularite využívania kompresie v rekreačnom a vrcholovom športe považujeme za kľúčové reálne posúdenie možných efektov. V tomto ohľade je súčasná odborná literatúra nejednotná. V prácach nachádzame výrazné potenciálne možné využitie KO, ktoré ovplyv- ňuje výkon i regeneráciu. Na druhej strane celá rada štúdií konštatuje žiadny alebo minimálny efekt na športový výkon a regeneráciu (hodnotené prevažne výkonové a biochemické parametre). Jednotlivé zistené dáta je však veľmi zložité porovnať, nakoľko prevažná väčšina prác neuvádza veľkosť pôsobiacej kompresie. V tomto bode chceme čitateľa práce upozorniť na základný problém, ktorý výrobca, resp. predajca KO častokrát neuvádza v informačnom popise produktu a to je práve veľkosť pôsobiacej kompresie. Preto považujeme za žiadúce ďalšie výskumné zámery smerovať do zistenia optimálneho tlaku pre výkon a regeneráciu. Uvedený zámer nám logicky nadväzuje na zistenie, že ak rozdielne kompresné tlaky vykazujú v sledovaných parametroch rozdielne výsledky, potom pravdepodobne bude existovať akýsi zlatý štandard voľby tlaku v závislosti od druhu vykonávanej pohybovej aktivity.
The main aim of this article is to emphasize the potential effect of compression clothing in a group of runners. We want to provide an objective view on evaluation of the advantages or potential risks in the use of compression clothing (socks or calf sleeves). This work is not a metanalysis, the purpose of this study provides basic information about the use of compression clothing. The work focuses on selected parameters which directly or indirectly determine the sport performance and affects the ability to repeat the sport performance. The scientific literature describes only two potential effects of compression clothing (increased venous flow and reduced muscle oscillation). As with most trends that come and go in sports, it takes a while to evaluate with the practice for the science. In our work, we focus on selected parameters with regard compression value. Based on scientific sources, the effect of compression clothing for sport performance and recovery is unclear. It is also caused by applied compression which is not also written in scientific literature. At this point, we want to emphasize this fact is probably important not only for future study design but also for customers. It makes sense if the different compression pressure lead to different results then it should exist the gold standard depending on the pressure and types of physical activity.
- Keywords
- komprese, trojhlavý sval lýtkový,
- MeSH
- Running * MeSH
- Compression Bandages * classification MeSH
- Muscle, Skeletal blood supply MeSH
- Humans MeSH
- Prevalence MeSH
- Regeneration MeSH
- Athletes MeSH
- Athletic Injuries epidemiology MeSH
- Athletic Performance MeSH
- Pressure MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Electroencephalography (EEG) experiments typically generate vast amounts of data due to the high sampling rates and the use of multiple electrodes to capture brain activity. Consequently, storing and transmitting these large datasets is challenging, necessitating the creation of specialized compression techniques tailored to this data type. This study proposes one such method, which at its core uses an artificial neural network (specifically a convolutional autoencoder) to learn the latent representations of modelled EEG signals to perform lossy compression, which gets further improved with lossless corrections based on the user-defined threshold for the maximum tolerable amplitude loss, resulting in a flexible near-lossless compression scheme. To test the viability of our approach, a case study was performed on the 256-channel binocular rivalry dataset, which also describes mostly data-specific statistical analyses and preprocessing steps. Compression results, evaluation metrics, and comparisons with baseline general compression methods suggest that the proposed method can achieve substantial compression results and speed, making it one of the potential research topics for follow-up studies.
- MeSH
- Adult MeSH
- Electroencephalography * methods MeSH
- Data Compression * methods MeSH
- Humans MeSH
- Neural Networks, Computer * MeSH
- Signal Processing, Computer-Assisted MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
The assessment of ECG signal quality after compression is an essential part of the compression process. Compression facilitates the signal archiving, speeds up signal transmission, and reduces the energy consumption. Conversely, lossy compression distorts the signals. Therefore, it is necessary to express the compression performance through both compression efficiency and signal quality. This paper provides an overview of objective algorithms for the assessment of both ECG signal quality after compression and compression efficiency. In this area, there is a lack of standardization, and there is no extensive review as such. 40 methods were tested in terms of their suitability for quality assessment. For this purpose, the whole CSE database was used. The tested signals were compressed using an algorithm based on SPIHT with varying efficiency. As a reference, compressed signals were manually assessed by two experts and classified into three quality groups. Owing to the experts' classification, we determined corresponding ranges of selected quality evaluation methods' values. The suitability of the methods for quality assessment was evaluated based on five criteria. For the assessment of ECG signal quality after compression, we recommend using a combination of these methods: PSim SDNN, QS, SNR1, MSE, PRDN1, MAX, STDERR, and WEDD SWT.
