Browsing by Author "Chen, Jin-Long"

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Better Thoracoabdominal Synchrony in Abdominal Breathing: Evidence From Complementary Ensemble Empirical Mode Decomposition-Based Lissajous Figure Analysis
(2015-04-01)
Chen, Ya-Chen
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Hsiao, Tzu-Chien
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Chen, Jin-Long
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分子醫學與生物工程研究所
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資訊工程學系
Abdominal breathing (AB) is believed to be a healthier pattern of breathing than thoracic breathing (TB). However, the objective evidence is scanty. Thoracoabdominal synchrony could be evaluated by calculating the phase angle between rib cage and abdomen motion in the Lissajous figure. A lesser phase angle indicates a better thoracoabdominal synchrony. Complementary ensemble empirical mode decomposition (CEEMD) was recently developed to extract the main component in the nonlinear and non-stationary signals. This study was designed to compare the thoracoabdominal synchrony between AB and TB via a CEEMD-based Lissajous figure analysis. Twenty-nine healthy subjects [24 males and 5 females; age 22 (21-23) years, median (interquartile range)] were recruited to receive simultaneous respiratory inductive plethysmography recording of rib cage and abdomen motion during AB and TB respectively. The main components of rib cage and abdomen motion were extracted by CEEMD. These main components were used to plot the Lissajous figure and calculate the phase angle. Compared with TB, AB revealed a significant decrease (P < 0.001) in phase angle [AB 12.13 (8.70-15.76)degrees vs. TB 22.56 (17.59-26.35)degrees]. In conclusion, AB assumes a better thoracoabdominal synchrony than TB. This finding might help to explain why AB is a healthier pattern of breathing. In addition, the CEEMD-based Lissajous figure analysis could be an effective method for the evaluation of thoracoabdominal synchrony.
Concurrent sympathetic activation and vagal withdrawal in hyperthyroidism: Evidence from detrended fluctuation analysis of heart rate variability
(2010-05-01)
Chen, Jin-Long
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Shiau, Yuo-Hsien
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Tseng, Yin-Jiun
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Chiu, Hung-Wen
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Hsiao, Tzu-Chien
Despite many previous Studies on the association between hyperthyroidism and the hyperadrenergic state, controversies still exist. Detrended fluctuation analysis (DFA) is a well recognized method in the nonlinear analysis of heart rate variability (HRV), and it has physiological significance related to the autonomic nervous system. In particular, an increased short-term scaling exponent alpha 1 calculated from DFA is associated with both increased sympathetic activity and decreased vagal activity. No study has investigated the DFA of HRV in hyperthyroidism. This study was designed to assess the sympathovagal balance in hyperthyroidism. We performed the DFA along with the linear analysis of HRV in 36 hyperthyroid Graves' disease patients (32 females and 4 males; age 30 +/- 1 years, means +/- SE) and 36 normal controls matched by sex, age and body mass index. Compared with the normal controls, the hyperthyroid patients revealed a significant increase (P < 0.001) in alpha 1 (hyperthyroid 1.28 +/- 0.04 versus control 0.91 +/- 0.02), long-term scaling exponent alpha 2 (1.05 +/- 0.02 versus 0.90 +/- 0.01), overall scaling exponent alpha (1.11 +/- 0.02 versus 0.89 +/- 0.01), low frequency power in normalized units (LF%) and the ratio of low frequency power to high frequency power (LF/HF); and a significant decrease (P < 0.001) in the standard deviation of the R-R intervals (SDNN) and high frequency power (HF). In conclusion, hyperthyroidism is characterized by concurrent sympathetic activation and vagal withdrawal. This sympathovagal imbalance state in hyperthyroidism helps to explain the higher prevalence of atrial fibrillation and exercise intolerance among hyperthyroid patients. (C) 2010 Elsevier B.V. All rights reserved.
Nonlinear analysis of heart rate dynamics in hyperthyroidism
(2007-04-01)
Chen, Jin-Long
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Tseng, Yin-Jiun
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Chiu, Hung-Wen
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Hsiao, Tzu-Chien
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Chu, Woei-Chyn
Studies on the physiology of the cardiovascular system suggested that the generation of the heart rate signal is governed by nonlinear chaotic dynamics. No study investigated the nonlinear dynamics of heart rate in hyperthyroidism. We examined whether the heart rate dynamics of hyperthyroid patients is different from normal controls by the nonlinear analysis of heart rate variability (HRV) with correlation dimension (CD). Thirty-three hyperthyroid Graves' disease patients (30 females and 3 males; age 31 +/- 1 years, means +/- SE) and 33 sex-, age-, and body mass index-matched normal controls were recruited to receive one-channel electrocardiogram recording for 30 min. The CD, an index of complexity, was computed from the sequence of normal R-R intervals by the Grassberger and Procaccia algorithm. Compared to the normal controls, the hyperthyroid patients showed significant reductions (P < 0.001) in the mean R-R interval (hyperthyroid 616 +/- 15 versus control 868 +/- 16 ms), the standard deviation of R-R intervals (25 +/- 2 versus 54 +/- 4 ms) and CD (5.02 +/- 0.11 versus 6.42 +/- 0.16). Our study demonstrated for the first time that hyperthyroid patients and normal controls could be distinguished by CD analysis of HRV. In addition, the decreased CD in hyperthyroid patients implies reduced complexity and impaired tolerance to cardiovascular stresses in hyperthyroidism. This finding helps to explain exercise intolerance and irritability manifested by the hyperthyroid patients.
Recognizing Thoracic Breathing by Ensemble Empirical Mode Decomposition
(2013-01-01)
Chen, Jin-Long
;
Chen, Ya-Chen
;
Hsiao, Tzu-Chien
;
資訊工程學系
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Department of Computer Science
Recognizing breathing pattern is important in many fields of medicine. Ensemble empirical mode decomposition (an adaptive algorithm) was used to investigate breathing pattern, including thoracic breathing (TB) and abdominal breathing (AB). This study recognizes TB and AB by correlation coefficient and power proportion. Results indicate that the recognition accuracy of TB by correlation coefficient and power proportion are 85.2% and 93.3% respectively, and that of AB by correlation coefficient and power proportion are 54.3% and 56.2% respectively. The TB can be well defined and recognized in complex time variation. These results can be used as references to develop the real time breathing evaluation system in the future.