scholarly journals GRAPHICAL METHODS FOR NON-LINEAR ANALYSIS OF ELECTROCARDIOGRAPHIC DATA

2019 ◽  
Vol 7 ◽  
Author(s):  
Evgeniya Gospodinova
Keyword(s):  
Healthy Subject ◽  
Healthy Subjects ◽  
Study Groups ◽  
Recurrence Plot ◽  
Quantitative Information ◽  
Linear Analysis ◽  
Graphical Methods ◽  
Healthy Controls ◽  
Poincaré Plot ◽  
Non Linear

INTRODUCTION: One of the most widely used methods for studying the bioelectric activity of the heart is the electrocardiogram (ECG). An important diagnostic parameter that can be determined by the ECG is heart rate variability (HRV), which takes into account the difference between successive strokes of the heart. Changing HRV can be an indicator of a number of disease states, such as low HRV levels can show poor health that is not only associated with cardiovascular disease but also with other diseases such as internal, nervous, mental, and other disorders. OBJECTIVES:  The subject of this article is the study of 24-hour ECG signals by applying non-linear graphical methods for HRV analysis. The non-linear graphical methods aim at obtaining graphical and quantitative information on the cardiovascular status of the study groups to complement the information obtained from traditional linear methods of analysis. METHODS: For the non-linear analysis of HRV, graphical methods were used: Poincaré plot and Recurrence plot were used, which are suitable for the examination of electrocardiographic signals. Two groups of people were investigated: 20 healthy controls and 20 patients with arrhythmia. RESULTS: Based on the nonlinear analysis of RR time series, the graphs of a healthy subject and a patient with arrhythmia were constructed using the Poincare plot. The graph of the healthy subject has the shape of a comet, while the graph of the patient with arrhythmia has the shape of a fan. The quantitative characteristics of patients with arrhythmia significantly change compared to the healthy subjects. The SD1 (p <0.003) and SD2 (p <0.0001) values decreased in patients with arrhythmia compared to the healthy controls. This reduction leads to reduction of the areas of the ellipse in the patients with arryhthmia. The ratio of SD1/SD2 (p <0.05) is lower for the healthy controls. The graphs obtained by the Recurrence plot of the investigated signals differ in healthy subjects and in patients with arrhythmia. For a healthy subject, the graph has a diagonal line and fewer squares showing a higher HRV. The graph of a patient with arrhythmia contains more squares, indicating periodicity in the investigated signal. The Recurrence Quantification Analysis showed that the values of the investigated parameters DET% (p <0.0001), REC% (p <0.0001) and ENTR (p <0.001) in patients with arrhythmia are increased. CONCLUSIONS:  The importance of the graphical nonlinear methods used for the analysis of HRV consists in forming a parametric and graphical assessment of the patient's health status.

scholarly journals Paravertebral Muscle Mechanical Properties in Patients with Axial Spondyloarthritis or Low Back Pain: A Case-Control Study

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1898
Author(s):  
Sandra Alcaraz-Clariana ◽  
Lourdes García-Luque ◽  
Juan Luis Garrido-Castro ◽  
I. Concepción Aranda-Valera ◽  
Lourdes Ladehesa-Pineda ◽  
...  
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Healthy Subjects ◽  
Axial Spondyloarthritis ◽  
Study Groups ◽  
Healthy Controls ◽  
Low Back ◽  
Negative Consequences ◽  
Muscle Properties ◽  
Clinical Variables

Different musculoskeletal disorders are a source of pain in the spinal region; most of them can be divided into mechanical, such as low back pain (LBP), or inflammatory origins, as is the case of axial spondyloarthritis (axSpA). Nevertheless, insufficient information is available about the muscle negative consequences of these conditions. Thus, the objective of this study was to identify whether mechanical muscle properties (MMPs) of cervical and lumbar muscles are different between patients with axSpA, subacute LBP (sLBP), and healthy controls. Furthermore, we aimed identify whether MMPs were related to sociodemographic and clinical variables in various study groups. The MMPs, sociodemographic, and clinical variables were obtained in 43 patients with axSpA, 43 subjects with sLBP, and 43 healthy controls. One-way ANOVAs and ROC curves were applied to identify whether the MMPs could differentiate between the study groups. Intra-group Pearson r coefficients to test the associations between MMPs and the rest of the variables were calculated. The results showed that axSpA subjects have a higher tone and stiffness and a lower relaxation and creep than sLBP and healthy ones (p < 0.05). All lumbar and cervical MMPs, except for decrement, could correctly classify axSpA and healthy subjects and axSpA and sLBP patients (in both cases, Area Under the Curve > 0.8). However, no MMP could differentiate between sLBP and healthy subjects. Each group had a different pattern of bivariate correlations between MMPs and sociodemographic and clinical data, with a worse state and progression of the axSpA group associated with a higher tone and stiffness in both spinal regions. This study supports that MMPs are different and show different patterns of correlations depending on the type of spinal pain.

Heart rate variability Non-Linear analysis by poincare plot in the complete glycemic spectrum

2018 ◽  
Vol 9 (10) ◽  
pp. 266
Author(s):  
Rajathi Rajendran ◽  
Vivek Kumar Sharma ◽  
Ramesh ◽  
K V Vinod ◽  
Hanumanthappa Nandeesha
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Linear Analysis ◽  
Poincaré Plot ◽  
Non Linear

scholarly journals Non-Linear Analysis of Air Pressure Fluctuations During Bubble Departure Synchronisation

2019 ◽  
Vol 13 (3) ◽  
pp. 158-165
Author(s):  
Paweł Dzienis ◽  
Romuald Mosdorf ◽  
Tomasz Wyszkowski ◽  
Gabriela Rafałko
Keyword(s):  
Data Analysis ◽  
Pressure Fluctuations ◽  
Recurrence Plot ◽  
Linear Analysis ◽  
Air Pressure ◽  
Fast Fourier Transformation ◽  
Largest Lyapunov Exponent ◽  
Pressure Oscillations ◽  
Air Supply ◽  
Non Linear

Abstract In the recent paper, non-linear methods of data analysis were used to study bubble departure synchronisation. In the experiment, bubbles were generated in engine oils from two neighbouring brass nozzles (with an inner diameter of 1 mm). During the experiment, the time series of air pressure oscillations in the air supply system and voltage changes on phototransistor were recorded. The analysis of bubble departure synchronisation was performed using a correlation coefficient. The following methods of non-linear data analysis are considered. Fast Fourier Transformation, autocorrelation, attractor reconstruction, correlation dimension, largest Lyapunov exponent and recurrence plot analysis were used to examine the correlation between bubbles behaviour and character of pressure fluctuations. Non-linear analysis of bubble departure synchronisation revealed that the way of bubble departures from two neighbouring nozzles does not depend simply on the character of pressure fluctuations in the nozzle air supply systems. The chaotic changes of the air pressure oscillations do not always determine the chaotic bubble departures.

Determination of Concrete Cube Strength from Used Samples / Určení Krychelné Pevnosti Betonu U Použitých Zkušebních Trámců

2012 ◽  
Vol 12 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Oldřich Sucharda ◽  
David Mikolášek ◽  
Jiří Brožovský
Keyword(s):  
Compressive Strength ◽  
Concrete Beams ◽  
Linear Analysis ◽  
Bending Tests ◽  
Cube Strength ◽  
Non Linear ◽  
Compressive Strength Of Concrete ◽  
Concrete Cube

Abstract This paper deals with the determination of compressive strength of concrete. Cubes, cylinders and re-used test beams were tested. The concrete beams were first subjected to three-point or fourpoint bending tests and then used for determination of the compressive strength of concrete. Some concrete beams were reinforced, while others had no reinforcement. Accuracy of the experiments and calculations was verified in a non-linear analysis.

Over-expression of IL-6 coding gene in the peripheral blood of migraine with aura patients

2021 ◽  
pp. 1-5
Author(s):  
Mahdi Ramezani ◽  
Alireza Komaki ◽  
Mohammad Mahdi Eftekharian ◽  
Mehrdokht Mazdeh ◽  
Soudeh Ghafouri-Fard
Keyword(s):  
Migraine With Aura ◽  
Peripheral Blood ◽  
Healthy Subjects ◽  
Migraine Without Aura ◽  
P Value ◽  
Healthy Controls ◽  
Over Expression ◽  
Significant Difference ◽  
Male Patients ◽  
Years Lived With Disability

Migraine is a common disorder which is placed among the top ten reasons of years lived with disability. Cytokines are among the molecules that contribute in the pathophysiology of migraine. In the current study, we evaluated expression levels of IL-6 coding gene in the peripheral blood of 120 migraine patients (54 migraine without aura and 66 migraine with aura patients) and 40 healthy subjects. No significant difference was detected in expression of IL-6 between total migraine patients and healthy controls (Posterior beta = 0.253, P value = 0.199). The interaction effect between gender and group was significant (Posterior beta =-1.274, P value = 0.011), therefore, we conducted subgroup analysis within gender group. Such analysis revealed that while expression of this gene is not different between male patients and male controls (Posterior beta =-0.371, P value > 0.999), it was significantly over-expressed in female patients compared with female controls (Posterior beta = 0.86, P= 0.002). Expression of IL-6 was significantly higher in patients with aura compared with controls (Posterior beta = 0.63, adjusted P value = 0.019). However, expression of this cytokine coding gene was not different between patients without aura and healthy subjects (Posterior beta = 0.193, adjusted P value = 0.281). Therefore, IL-6 might be involved in the pathophysiology of migraine among females and migraine with aura among both sexes.

scholarly journals A non-linear analysis of running in the heavy and severe intensity domains

2021 ◽  
Author(s):  
Ben Hunter ◽  
Andrew Greenhalgh ◽  
Bettina Karsten ◽  
Mark Burnley ◽  
Daniel Muniz-Pumares
Keyword(s):  
Linear Analysis ◽  
Severe Intensity ◽  
Non Linear
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