A literature review of the methodology of EMG recordings of the diaphragm.

INTRODUCTION EMG measurements of the diaphragm (rEMG) provide insight in to ventilatory muscle activity. Applicability of these measurements has improved, but literature of the different rEMG measurement techniques is inconsistent. This makes it difficult to compare studies of rEMG technique. This study summarizes the current available literature on rEMG and focuses on the validation of the techniques. Furthermore, we propose to use validation criteria to improve the quality, for further research. METHODS Pubmed, Ovid Medline and EMBASE were searched for studies describing rEMG experiments with transcutaneous (tc-rEMG) and/or transesophageal (te-rEMG) methods.Validation criteria included feasibility, repeatability, signal disturbance and ECG gating. RESULTS 650 studies were eligible for reviewing; 211 were excluded, and 39 articles described the measurement technique and were analyzed according to the criteria. 194 studies referred to another paper with a description of the technique and 206 failed to describe the technique nor had references to it. CONCLUSIONS Many studies showed neither a description of the technique used, nor a validation of this technique. Others referred to studies that described the measurement technique. We propose that future studies on rEMG measurements at least meet the above mentioned criteria, in order to be able to compare study results.