Journal of Healthcare Engineering

Journal of Healthcare Engineering / 2010 / Article

Research Article | Open Access

Volume 1 |Article ID 141289 |

Wei-Ren Chuang, Jia-Rong Yeh, Li-Kuei Chen, Yin-Yi Han, Jiann-Shing Shieh, "Investigation of the Effects of Continuous Low-Dose Epidural Analgesia on the Autonomic Nervous System Using Hilbert Huang Transform", Journal of Healthcare Engineering, vol. 1, Article ID 141289, 14 pages, 2010.

Investigation of the Effects of Continuous Low-Dose Epidural Analgesia on the Autonomic Nervous System Using Hilbert Huang Transform


Effects of continuous low-dose epidural bupivacaine (0.05-0.1%) infusion on the Doppler velocimetry for labor analgesia have been well documented. The aim of this study was to monitor the activity of the autonomic nervous system (ANS) for women in labor based on Hilbert Huang transform (HHT), which performs signal processing for nonlinear systems, such as human cardiac systems. Thirteen pregnant women were included in the experimental group for labor analgesia. They received continuous epidural bupivacaine 0.075% infusion. The normal-to-normal intervals (NN-interval) were downloaded from an ECG holter. Another 20 pregnant women in non-anesthesia labor (average gestation age was 38.6 weeks) were included in the comparison group. In this study, HHT was used to decompose components of ECG signals, which reflect three different frequency bands of a person's heart rate spectrum (viz. high frequency (HF), low frequency (LF) and very low frequency (VLF)). It was found that the change of energy in subjects without anesthesia was more active than that with continuous epidural bupivacaine 0.075% infusion. The energy values of the experimental group (i.e., labor analgesia) of HF and LF of ANS activities were significantly lower (P < 0.05) than the values of the comparison group (viz. labor without analgesia), but the trend of energy ratio of LF/HF was opposite. In conclusion, the sympathetic and parasympathetic components of ANS are all suppressed by continuous low-dose epidural bupivacaine 0.075% infusion, but parasympathetic power is suppressed more than sympathetic power.


  1. L. K. Chen, C. J. Lin, C. H. Huang et al., “The effects of continuous epidural analgesia on Doppler velocimetry of uterine arteries during different periods of labor analgesia,” British Journal of Anaesthesia, vol. 96, pp. 226–230, 2006. View at: Google Scholar
  2. S. Akselrod, D. Gordon, F. A. Ubel, D. C. Shannonet, A. C. Barger, and R. J. Cohen, “Power spectrum analysis of heart rate fluctuation: a quantitative probe of beat-to-beat cardiovascular control,” Science, vol. 213, no. 10, pp. 220–222, 1981. View at: Google Scholar
  3. A. Lindqvist, “Noninvasive methods to study autonomic nervous control of circulation,” Acta Physiological Scandinavica, Suppl., vol. 588, pp. 1–107, 1990. View at: Google Scholar
  4. R. Introna, E. Yodlowski, J. Pruett, N. Montano, A. Porta, and R. Crumrine, “Sympathovagal effects of spinal anesthesia assessed by heart rate variability analysis,” Anesth Analg, vol. 80, pp. 315–321, 1995. View at: Google Scholar
  5. A. Deschamps, I. Kaufman, S. B. Backman, and G. Plourde, “Autonomic nervous system response to epidural analgesia in laboring patients by wavelet transform of heart rate and blood pressure variability,” Anesthesiology, vol. 101, pp. 21–27, 2004. View at: Google Scholar
  6. D. P. Landry, F. M. Bennett, and N. E. Oriol, “Analysis of heart rate dynamics as a measure of autonomic tone in obstetrical patients undergoing epidural or spinal anesthesia,” Reg Anesth, vol. 19, pp. 189–195, 1994. View at: Google Scholar
  7. J. T. Bigger Jr., J. L. Fleiss, R. C. Stemman, L. M. Rolnizky, R. E. Kleiger, and J. N. Rottman, “Frequency domain measures of heart period variability and mortality after myocardial infarction,” Circulation, vol. 85, pp. 164–171, 1992. View at: Google Scholar
  8. N. E. Huang, Z. Shen, S. R. Long et al., “The empirical mode decomposition and the Hilbert Spectrum for nonlinear and nonstationary time series analysis,” Proceedings of Royal Society of London, Series A, vol. 454, pp. 903–995, 1998. View at: Google Scholar
  9. E. Bedrosian, “A product theorem for Hilbert transform,” Proc. IEEE, vol. 51, pp. 868–869, 1963. View at: Google Scholar
  10. M. F. Abbod, J. S. Shieh, J. R. Yeh, K. Y. Cheng, S. J. Huang, and Y. Y. Han, “Intelligent Systems for the Prediction of Brain Death Index,” in IEEE Biocas2008 conference, Baltimore, USA, November 20 - 22 2008. View at: Google Scholar
  11. J. S. Shieh, M. F. Abbod, J. R. Yeh, K. Y. Cheng, S. J. Huang, and Y. Y. Han, “Hard and soft computing applied to prediction of brain-death patients categories in neurosurgical intensive care units,” in Artificial Intelligence: New Research, R. B. Bernstein and W. N. Curtis, Eds., pp. 379–403, Nova Science Publishers, 2009. View at: Google Scholar
  12. The operation manual of MYECG E-380, publication of Micro-Star International, 2007.
  13. W. H. Kruskal and W. A. Wallis, “Use of Ranks in One-Criterion Variance analysis,” Journal of the American Statistical Association, vol. 47, pp. 583–621, 1952. View at: Google Scholar
  14. A. Mortara, M. T. La Rovere, M. G. Signorini et al., “Can power spectral analysis of heart rate variability identify a high risk subgroup of congestive heart failure patients with excessive sympathetic activation? A pilot study before and after heart transplantation,” Br. Heart Journal, vol. 71, no. 5, pp. 422–430, 1994. View at: Google Scholar
  15. B. Pomeranz, R. J. B. Macaulay, M. A. Caudill et al., “Assessment of autonomic function in humans by heart rate spectral analysis,” Am. J. Physiol. Heart Circ. Physiol., vol. 248, pp. H151–H153, 1985. View at: Google Scholar
  16. M. Pagani, F. Lombardi, S. Guzzetti et al., “Power spectral analysis of heart rate and arterial pressure variabilities as a marker of sympatho-vagal interaction in man and conscious dog,” Circ. Res., vol. 59, pp. 178–193, 1986. View at: Google Scholar
  17. R. G. Yeh, J. S. Shieh, G. Y. Chen, and D. D. Kuo, “Detrended fluctuation analysis of short-term heart rate variability in late pregnant women,” Autonomic Neuroscience-Basic & Clinical, 2009 (article in press). View at: Google Scholar

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