Analysis of diaphragm emg signals: comparison of gating vs
subtraction for removal of ecg contamination.
Bartolo, A., C. Roberts, R. R. Dzwonczyk, and E. Goldman.
Biomedical Engineering Center, The Ohio State University, Columbus,
Ohio 43210; and Department of Anesthesiology, The Ohio State
University Hospitals, Columbus, Ohio 43210
APStracts 3:0058A, 1996.
The diaphragm electromyogram (EMGdi) conveys information relating to
the mechanisms of respiration, however electrocardiogram (ECG)
contamination can compromise the accuracy of data derived from this
signal. We examine the EMGdi recorded from anesthetized spontaneously
breathing dogs via implanted electrodes to assess the extent of the
error introduced by the ECG contamination and the effectiveness of
ECG gating in reducing this error. Since ECG subtraction has been
shown to generate accurate results for such applications it is used
as the gold standard. ANOVA methods are employed to compare results
derived from the EMGdi data after ECG subtraction to corresponding
results derived from the original data and from the data after ECG
gating. Estimates of EMGdi variables obtained using subtraction and
gating techniques were not significantly different, indicating that
gating can be employed on these signals to reduce ECG contamination
without affecting the accuracy of the derived data. Results also show
that at EMG-to-ECG power ratios above 13.3 dB, ECG contamination does
not significantly affect estimates of the EMGdi variables.
Received 4 October 1995; accepted in final form 10 January 1996.
APS Manuscript Number A1072-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 February 96