Comparing ECG Artifact Removal Methods for Diaphragm EMG during Inspiratory Pressure-Threshold Loading: Effects on...

Area of Science:

• Respiratory Physiology
• Biomedical Engineering
• Electrophysiology

Background:

• Diaphragm electromyogram (EMGdi) measurement via esophageal catheters is prone to electrocardiographic (ECG) artifact.
• Cardiac electrical activity contamination can compromise EMGdi signal quality and interpretation.
• Understanding sex-based differences in artifact reduction is crucial for accurate physiological assessment.

Purpose of the Study:

• To compare artifact reduction methods for esophageal EMGdi signals.
• To investigate sex-based differences in the effectiveness of these methods.
• To evaluate the impact of artifact reduction on the EMGdi-force output relationship (PTPdi).

Main Methods:

• Sixteen healthy adults (7 female, 9 male) underwent inspiratory pressure threshold loading (PTL).
• Esophageal EMGdi and simultaneous ECG were recorded.
• Four processing methods were compared: ECG-R (QRS exclusion), ICA, ICA-W (ICA with wavelet transformation), and RAW (no artifact removal).

Main Results:

• No significant differences in EMGdi-PTL relationships were found between sexes or processing methods.
• EMGdi was significantly associated with PTPdi across all methods in both sexes.
• In females, the EMGdi-PTPdi association was weaker with ICA and ICA-W compared to ECG-R.

Conclusions:

• All tested methods effectively reduce ECG artifact during PTL with low heart rates.
• ICA and ICA-W are viable alternatives when a simultaneous ECG is unavailable.
• ECG-guided QRS exclusion (ECG-R) is the preferred method for studies correlating EMGdi with diaphragm force output.