Abstract:
:Spectral analysis of heart rate variability (HRV) is used for the assessment of cardiovascular autonomic control. In this study, a data-driven adaptive technique called empirical mode decomposition (EMD) and the associated Hilbert spectrum has been used to evaluate the effect of local anaesthesia on HRV parameters in a group of 14 patients undergoing axillary brachial plexus block. The normalized amplitude Hilbert spectrum was used to calculate the error index associated with the instantaneous frequency. The amplitude and the frequency values were corrected in the region where the error was higher than twice standard deviation. The intrinsic mode function (IMF) components were assigned to the LF and the HF part of the signal by making use of the centre frequency and the standard deviation spectral extension estimated from the marginal spectrum of the IMF components. The optimal range of the stopping criterion was found to be between 4 and 9 for the HRV data. The statistical analysis showed that the LF/HF ratio decreased within an hour of the application of the brachial plexus block compared to the values at the start of the procedure. These changes were observed in 13 of the 14 patients included in this study.
journal_name
Physiol Measjournal_title
Physiological measurementauthors
Shafqat K,Pal SK,Kumari S,Kyriacou PAdoi
10.1088/0967-3334/32/4/008subject
Has Abstractpub_date
2011-04-01 00:00:00pages
483-97issue
4eissn
0967-3334issn
1361-6579pii
S0967-3334(11)65572-Xjournal_volume
32pub_type
临床试验,杂志文章abstract:OBJECTIVE:To provide a non-invasive approach to monitoring lung function in spontaneously breathing lambs, from birth to five months of life, by the forced oscillation technique (FOT). This report describes the experimental set-up, data processing, and identification of normal predicted values of resistance (Rrs) and r...
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更新日期:2019-11-04 00:00:00
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