TIME DELAY BETWEEN RR AND RT HEART BEAT INTERVALS ASSESSED BY TREND EXTRACTION OF EXERCISE TEST DATA

2012 ◽  
Vol 11 (04) ◽  
pp. 1250019 ◽  
Author(s):  
CAMILLO CAMMAROTA ◽  
MARIO CURIONE
Keyword(s):  
Time Delay ◽  
Exercise Test ◽  
Heart Beat ◽  
Time Intervals ◽  
Multi Scale ◽  
Trend Extraction ◽  
Polynomial Fit ◽  
Deterministic Trend ◽  
Trend Data ◽  
Random Fluctuations

The RR and RT time intervals extracted from the electrocardiogram measure respectively the duration of cardiac cycle and repolarization. The series of these intervals recorded during the exercise test are characterized by two trends: A decreasing one during the stress phase and an increasing one during the recovery, separated by a global minimum. We model these series as a sum of a deterministic trend and random fluctuations, and estimate the trend using methods of curve extraction: Running mean, polynomial fit, multi scale wavelet decomposition. We estimate the minimum location from the trend. Data analysis performed on a group of 20 healthy subjects provides evidence that the minimum of the RR series precedes the minimum of the RT series, with a time delay of about 19 seconds.

scholarly journals Multi-Scale Heart Beat Entropy Measures for Mental Workload Assessment of Ambulant Users

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 783 ◽  
Author(s):  
Abhishek Tiwari ◽  
Isabela Albuquerque ◽  
Mark Parent ◽  
Jean-François Gagnon ◽  
Daniel Lafond ◽  
...  
Keyword(s):  
Physical Activity ◽  
Mental Workload ◽  
Real Life ◽  
Heart Beat ◽  
Activity Levels ◽  
Safety Hazards ◽  
Constant Attention ◽  
Multi Scale ◽  
Entropy Measures ◽  
Ecg Artifacts

Mental workload assessment is crucial in many real life applications which require constant attention and where imbalance of mental workload resources may cause safety hazards. As such, mental workload and its relationship with heart rate variability (HRV) have been well studied in the literature. However, the majority of the developed models have assumed individuals are not ambulant, thus bypassing the issue of movement-related electrocardiography (ECG) artifacts and changing heart beat dynamics due to physical activity. In this work, multi-scale features for mental workload assessment of ambulatory users is explored. ECG data was sampled from users while they performed different types and levels of physical activity while performing the multi-attribute test battery (MATB-II) task at varying difficulty levels. Proposed features are shown to outperform benchmark ones and further exhibit complementarity when used in combination. Indeed, results show gains over the benchmark HRV measures of 24 . 41 % in accuracy and of 27 . 97 % in F1 score can be achieved even at high activity levels.

scholarly journals The Optimized Multi-Scale Permutation Entropy and Its Application in Compound Fault Diagnosis of Rotating Machinery

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 170 ◽  
Author(s):  
Xianzhi Wang ◽  
Shubin Si ◽  
Yu Wei ◽  
Yongbo Li
Keyword(s):  
Time Delay ◽  
Parameter Selection ◽  
Permutation Entropy ◽  
Embedding Dimension ◽  
Optimization Strategy ◽  
Extraction Ability ◽  
Dynamic Changes ◽  
Multi Scale ◽  
Simulated Signal ◽  
Selection Of

Multi-scale permutation entropy (MPE) is a statistic indicator to detect nonlinear dynamic changes in time series, which has merits of high calculation efficiency, good robust ability, and independence from prior knowledge, etc. However, the performance of MPE is dependent on the parameter selection of embedding dimension and time delay. To complete the automatic parameter selection of MPE, a novel parameter optimization strategy of MPE is proposed, namely optimized multi-scale permutation entropy (OMPE). In the OMPE method, an improved Cao method is proposed to adaptively select the embedding dimension. Meanwhile, the time delay is determined based on mutual information. To verify the effectiveness of OMPE method, a simulated signal and two experimental signals are used for validation. Results demonstrate that the proposed OMPE method has a better feature extraction ability comparing with existing MPE methods.

Randomly forced Rayleigh-Bénard convection

1980 ◽  
Vol 98 (2) ◽  
pp. 329-348 ◽  
Author(s):  
Bharat Jhaveri ◽  
G. M. Homsy
Keyword(s):  
Convective Transport ◽  
Time Intervals ◽  
Onset Of Convection ◽  
Nonlinear Convection ◽  
Bénard Convection ◽  
Benard Convection ◽  
Random Fluctuations ◽  
Rayleigh Benard Convection ◽  
Rayleigh Numbers ◽  
Rayleigh Benard

We consider the onset of Rayleigh–Bénard convection from random fluctuations arising within a fluid. In the specific case in which the fluctuations are thermodynamically determined, we reduce the problem to a random initial value problem for the Fourier modes. For the case of weak nonlinear convection, it is possible to truncate the number of modes and this truncated set is solved both by a Monte Carlo technique and by moment methods for various Rayleigh numbers. We find three stages in the evolution of ordered convection from random fluctuations which correspond to time intervals in which the fluctuations and the nonlinearity have different degrees of importance. It is shown that no simple moment truncation method will succeed and that the time for onset of convection is a mean over a distribution of times for which members of an ensemble exhibit appreciable convective transport.

scholarly journals Carbon dioxide as a short-term restraint anaesthetic in rats with subclinical respiratory disease

1989 ◽  
Vol 23 (3) ◽  
pp. 220-228 ◽  
Author(s):  
D. C. Fenwick ◽  
J. K. Blackshaw
Keyword(s):  
Carbon Dioxide ◽  
Respiratory Disease ◽  
Wistar Rats ◽  
Effective Means ◽  
Heart Beat ◽  
Short Term ◽  
Time Intervals ◽  
The Third ◽  
Minimal Time

The use of carbon dioxide (CO2) with, and without, oxygen (O2) as a short-term restraint anaesthetic for Wistar rats in which subclinical respiratory disease was endemic, was assessed in 3 separate experiments. In the first, rats were placed in a CO2 atmosphere generated from solid CO2 chips in a 701 plastic bin, and removed at time intervals ranging from 0 to 120 s after disappearance of the pedal reflex. Eight of 25 rats died, including 2 which were removed immediately the pedal reflex disappeared; it was concluded that CO2 without O2 was not a suitable short-term anaesthetic for rats. In a second study, rats were anaesthetized in atmospheres of 50 : 50 and 80 : 20 (CO2 : O2) provided from commercially available cylinders, in 2 different environments-a 3·41 glass jar and a 171 plastic bin. Rats became excited in the plastic bin but not the glass jar. Rats in the glass jar displayed visible depression and cessation of whiskers movement significantly more quickly in the 80 : 20 (CO2 : O2) than in the 50 : 50 mixture (4·2±0·98 s, n = 6, and 66·0±4·9 s, n = 6 vs 13·8±2·77 s, n = 5 and 1520±20·8 s, n = 5, respectively). Rats in the 171 plastic bin lost their pedal reflexes in a mean 41·5±4·55 s ( n = 11) in the 50 : 50 mixture and in a mean 30·9±6·38 s ( n = 11) in the 80 : 20 (CO2 : O2) group. Those left in the 50 : 50 mixture for 60 sand 180 s after disappearance of their pedal reflexes, recovered these reflexes in 20·2±0·44 s and 21·5±7·23 s respectively after removal from the gas. Respiration and heart beat ceased in one rat remaining in the 50 : 50 mixture after 13 min 10 s. No untoward effects occurred in rats left in the 50 : 50 mixture for 180 s after disappearance of the pedal reflex, but 2 died when left for an equivalent period in the 80 : 20 mixture. In the third study, examples of the practical use of a 50 : 50 mixture as a short term restraint anaesthetic are described. It was concluded that this mixture was a cheap, safe, and effective means of short-term restraint for rats with subclinical respiratory disease, when the minimal time of exposure to the gases was employed.

scholarly journals Non-random fluctuations and multi-scale dynamics regulation of human activity

2004 ◽  
Vol 337 (1-2) ◽  
pp. 307-318 ◽  
Author(s):  
Kun Hu ◽  
Plamen Ch. Ivanov ◽  
Zhi Chen ◽  
Michael F. Hilton ◽  
H.Eugene Stanley ◽  
...  
Keyword(s):  
Human Activity ◽  
Multi Scale ◽  
Random Fluctuations

scholarly journals Multi‐scale approach for simulating time‐delay biochemical reaction systems

2015 ◽  
Vol 9 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Yuanling Niu ◽  
Kevin Burrage ◽  
Chengjian Zhang
Keyword(s):  
Time Delay ◽  
Biochemical Reaction ◽  
Reaction Systems ◽  
Multi Scale

Potassium exchange between bathing solution and midgut of Hyalophora cecropia and time delay for potassium flux through the midgut

1975 ◽  
Vol 63 (1) ◽  
pp. 295-300
Author(s):  
K. Zerahn
Keyword(s):  
Time Delay ◽  
Bathing Solution ◽  
Time Intervals ◽  
Potassium Flux ◽  
Hyalophora Cecropia ◽  
Potassium Exchange

Exchange between potassium of the isolated midgut of the American silkworm Hyalophora cecropia and the bathing solutions has been determined by different authors, but with contradictory results. Therefore the experiments were repeated with another technique and the exchange determined for varying time intervals. It was found that the exchange was fast-half of the midgut K was exchanged in 2–3 minutes, which confirms the earlier findings by Harvey & Zerahn (1969).

Burst-Type Acoustic Emission Source Localization Based on Multi-Scale and Multi-Sensors

2013 ◽  
Vol 380-384 ◽  
pp. 2954-2957
Author(s):  
Xiao Tao Zhang ◽  
Li Wei Tang ◽  
Ping Wang ◽  
Xing Xing Han ◽  
Shi Jie Deng
Keyword(s):  
Acoustic Emission ◽  
Time Delay ◽  
Source Localization ◽  
Acoustic Emission Signal ◽  
Emission Source ◽  
Scale Analysis ◽  
Emission Signal ◽  
Multi Scale ◽  
Acoustic Emission Source ◽  
Multi Scale Analysis

For the burst-type acoustic emission signal, time delay estimation of two sensors calculated by signal cross-correlation is not accurate, and it leads the source localization results is not also accurate. A new method is proposed to improve accuracy of source localization results based on multi-scale analysis and multi-sensors. Acoustic emission signal multi-scale analysis using wavelet transform, then the most accurate time delay is selected in sub-band of signal multi-scale analysis by multi-sensors time delay vector close rule. Finally, the simulation acoustic emission source localization experiment has high accuracy.

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