Needle EMG of the diaphragm was performed in 43 diaphragms in 23 healthy volunteers. The mean -rstandard deviation for the median frequency (MF) of the power spectrum was 233.3 5 58.1 Hz. The MF increased with age and showed a negative correlation with the forced vital capacity (FVC), but there was
Multivariate analysis of diaphragm EMG power spectral moments
β Scribed by J.Milton Adams; T.K. Aldrich; N.S. Arora; D.F. Rochester
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 686 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0010-4809
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β¦ Synopsis
A single derived index of the power spectrum of the diaphragm electromyogram (EMG) has been used in detecting fatigue. Additional information in the EMG could be used to study diaphragm function in other respiratory conditions. Diaphragm EMGs and calculated power spectra at 12 frequencies were measured in normal subjects and patients with severe chronic obstructive pulmonary disease during several respiratory maneuvers both before and after treadmill exercise to dyspnea. The power spectra were characterized by the first five moments. Changes in the EMG were similar when assessed by multivariate analysis of variance of the spectral estimates or of the moments. Factor analysis provided two latent variables that correlated with the first and second moment respectively. The first moment was found to be the most sensitive single discriminant of fatigue and is only slightly improved by adding other information. It is concluded that the first and second moments of the EMG power spectra provide a concise, parsimonious description of the changes in the EMG.
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