scholarly journals Entropy Analysis for the Evaluation of Respiratory Changes Due to Asbestos Exposure and Associated Smoking

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 225
Author(s):  
Paula Sá ◽  
Hermano Castro ◽  
Agnaldo Lopes ◽  
Pedro Melo
Keyword(s):  
Respiratory System ◽  
Asbestos Exposure ◽  
Relevant Information ◽  
Sample Entropy ◽  
Respiratory Impedance ◽  
Entropy Analysis ◽  
Airflow Pattern ◽  
Recurrence Period ◽  
Adequate Accuracy ◽  
Recurrence Period Density Entropy

Breathing is a complex rhythmic motor act, which is created by integrating different inputs to the respiratory centres. Analysing nonlinear fluctuations in breathing may provide clinically relevant information in patients with complex illnesses, such as asbestosis. We evaluated the effect of exposition to asbestos on the complexity of the respiratory system by investigating the respiratory impedance sample entropy (SampEnZrs) and recurrence period density entropy (RPDEnZrs). Similar analyses were performed by evaluating the airflow pattern sample entropy (SampEnV’) and recurrence period density entropy (RPDEnV’). Groups of 34 controls and 34 asbestos-exposed patients were evaluated in the respiratory impedance entropy analysis, while groups of 34 controls and 30 asbestos-exposed patients were investigated in the analysis of airflow entropy. Asbestos exposition introduced a significant reduction of RPDEnV’ in non-smoker patients (p < 0.0004), which suggests that the airflow pattern becomes less complex in these patients. Smoker patients also presented a reduction in RPDEnV’ (p < 0.05). These finding are consistent with the reduction in respiratory system adaptability to daily life activities observed in these patients. It was observed a significant reduction in SampEnV’ in smoker patients in comparison with non-smokers (p < 0.02). Diagnostic accuracy evaluations in the whole group of patients (including non-smokers and smokers) indicated that RPDEnV’ might be useful in the diagnosis of respiratory abnormalities in asbestos-exposed patients, showing an accuracy of 72.0%. In specific groups of non-smokers, RPDEnV’ also presented adequate accuracy (79.0%), while in smoker patients, SampEnV’ and RPDEnV’ presented adequate accuracy (70.7% and 70.2%, respectively). Taken together, these results suggest that entropy analysis may provide an early and sensitive functional indicator of interstitial asbestosis.

scholarly journals Multiscale Sample Entropy of Two-Dimensional Decaying Turbulence

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 245
Author(s):  
Ildoo Kim
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Soap Film ◽  
Sample Entropy ◽  
Series Data ◽  
Entropy Analysis ◽  
Measured Time ◽  
Energetic Analysis ◽  
Turbulence Data ◽  
Decaying Turbulence

Multiscale sample entropy analysis has been developed to quantify the complexity and the predictability of a time series, originally developed for physiological time series. In this study, the analysis was applied to the turbulence data. We measured time series data for the velocity fluctuation, in either the longitudinal or transverse direction, of turbulent soap film flows at various locations. The research was to assess the feasibility of using the entropy analysis to qualitatively characterize turbulence, without using any conventional energetic analysis of turbulence. The study showed that the application of the entropy analysis to the turbulence data is promising. From the analysis, we successfully captured two important features of the turbulent soap films. It is indicated that the turbulence is anisotropic from the directional disparity. In addition, we observed that the most unpredictable time scale increases with the downstream distance, which is an indication of the decaying turbulence.

Inverse sample entropy analysis for stock markets

2021 ◽  
Author(s):  
Yue Wu ◽  
Pengjian Shang ◽  
Jianan Xia
Keyword(s):  
Stock Markets ◽  
Sample Entropy ◽  
Entropy Analysis

Fluctuations and determinism of respiratory impedance in asthma and chronic obstructive pulmonary disease

2010 ◽  
Vol 109 (6) ◽  
pp. 1582-1591 ◽  
Author(s):  
Michael Muskulus ◽  
Annelies M. Slats ◽  
Peter J. Sterk ◽  
Sjoerd Verduyn-Lunel
Keyword(s):  
Time Series ◽  
Power Law ◽  
Respiratory System ◽  
Single Frequency ◽  
Fluctuation Analysis ◽  
High Temporal Resolution ◽  
Deterministic System ◽  
Forced Oscillation Technique ◽  
Respiratory Impedance ◽  
Wasserstein Distances

Asthma and COPD are chronic respiratory diseases that fluctuate widely with regard to clinical symptoms and airway obstruction, complicating treatment and prediction of exacerbations. Time series of respiratory impedance obtained by the forced oscillation technique are a convenient tool to study the respiratory system with high temporal resolution. In previous studies it was suggested that power-law-like fluctuations exist also in the healthy lung and that respiratory system impedance variability differs in asthma. In this study we elucidate such differences in a population of well-characterized subjects with asthma ( n = 13, GINA 1+2), COPD ( n = 12, GOLD I+II), and controls ( n = 10) from time series at single frequency (12 min, f = 8 Hz). Maximum likelihood estimation did not rule out power-law behavior, accepting the null hypothesis in 17/35 cases ( P > 0.05) and with significant differences in exponents for COPD ( P < 0.03). Detrended fluctuation analysis exhibited scaling exponents close to 0.5, indicating few correlations, with no differences between groups ( P > 0.14). In a second approach, we considered asthma and COPD as dynamic diseases, corresponding to changes of unknown parameters in a deterministic system. The similarity in shape between the combined probability distributions of normalized resistance and reactance was quantified by Wasserstein distances and reliably distinguished the two diseases (cross-validated predictive accuracy 0.80; sensitivity 0.83, specificity 0.77 for COPD). Wasserstein distances between 3+3 dimensional phase space reconstructions resulted in marginally better classification (accuracy 0.84, sensitivity 0.83, specificity 0.85). These latter findings suggest that the dynamics of respiratory impedance contain valuable information for the diagnosis and monitoring of patients with asthma and COPD, whereas the value of the stochastic approach is not clear presently.

Measurement of total respiratory impedance in calves by the forced oscillation technique

1988 ◽  
Vol 64 (5) ◽  
pp. 1786-1791 ◽  
Author(s):  
P. Gustin ◽  
A. R. Dhem ◽  
F. Lomba ◽  
P. Lekeux ◽  
K. P. Van de Woestijne ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Fourier Analysis ◽  
Respiratory System ◽  
Pressure Wave ◽  
Forced Oscillation ◽  
Forced Oscillation Technique ◽  
Respiratory Impedance ◽  
Upper Airways ◽  
Low Frequencies ◽  
Spontaneously Breathing

We have determined the resistance (Rrs) and the reactance (Xrs) of the total respiratory system in unsedated spontaneously breathing calves at various frequencies. A pseudorandom noise pressure wave was produced at the nostrils of the animals by means of a loudspeaker adapted to the nose by a tightly fitting mask. A Fourier analysis of the pressure in the nostrils and flow signals yielded mean Rrs and Xrs, over 16 s, at frequencies of 2–26 Hz. A good correlation was found between values of pulmonary resistances measured by the isovolume method at the respiratory frequency of animals and values obtained at a frequency of 6 Hz by use of our technique. The linearity of the respiratory system, the reproducibility of the technique, and the effects of upper airways on results have been studied. In healthy calves, Rrs increases with frequency. Mean resonant frequency is 7.5 Hz. Bronchospasm was induced in six calves by administration of intravenous organophosphates. Rrs tended to decrease with increasing frequency. Resonant frequency exceeded 26 Hz. All parameters returned to initial values after administration of atropine. In healthy calves, atropine produces a decrease in Rrs, especially at low frequencies. Values of resonant frequency are not modified.

Mechanical aspects of panting in dogs

1962 ◽  
Vol 17 (2) ◽  
pp. 249-251 ◽  
Author(s):  
Eugene C. Crawford
Keyword(s):  
Resonant Frequency ◽  
Natural Frequency ◽  
Respiratory System ◽  
Volume Flow ◽  
Respiratory Impedance ◽  
Maximum Volume ◽  
The Mean ◽  
Incandescent Lamps ◽  
Apparently Healthy

Apparently healthy, unanesthetized dogs weighing 12.3 ± 1.8 kg were caused to pant by the warming effect of incandescent lamps. Panting frequency was recorded and found to be 5.33 ± 0.7 cycles/sec. The natural frequency of the respiratory system of each of the animals was then determined, the mean being 5.28 ± 0.3 cycles/sec. The increased effectiveness of panting at the resonant frequency of the respiratory system is discussed in terms of respiratory impedance and maximum volume flow with least effort. The impracticality of panting at other frequencies is shown by calculation. Submitted on August 2, 1961

scholarly journals Sample entropy analysis of cervical neoplasia gene-expression signatures

2009 ◽  
Vol 10 (1) ◽  
Author(s):  
Shaleen K Botting ◽  
Jerome P Trzeciakowski ◽  
Michelle F Benoit ◽  
Salama A Salama ◽  
Concepcion R Diaz-Arrastia
Keyword(s):  
Gene Expression ◽  
Cervical Neoplasia ◽  
Sample Entropy ◽  
Entropy Analysis ◽  
Gene Expression Signatures

Continuous sample entropy analysis

2010 ◽  
Vol 25 (3) ◽  
pp. e7-e8
Author(s):  
Douglas Lake
Keyword(s):  
Sample Entropy ◽  
Entropy Analysis
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