RT Journal Article
SR Electronic
T1 Limitations of superficial EMG estimate of parasternal intercostal muscle activity
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP PA1866
DO 10.1183/1393003.congress-2017.PA1866
VO 50
IS suppl 61
A1 Giovanni Tagliabue
A1 Micheal Ji
A1 Jenny Jagers
A1 Devin Dean
A1 Eric Wilde
A1 Paul Easton
YR 2017
UL http://erj.ersjournals.com/content/50/suppl_61/PA1866.abstract
AB Introduction: Recently, surface EMG estimating parasternal intercostal muscle (PARA) activity has been presented as neural respiratory drive (NRD). Historically the deep anatomy of PARA risked undesired EMG “crosstalk” signals from neighboring chest wall muscles. To date, no study compared PARA EMG activity recorded from direct fine wire implants, to surface EMG estimates.Aims: To assess whether surface EMG reliably represents intramuscular PARA EMG activity recorded by implanted fine wires.Methods: We implanted fine wires into PARA 2nd right intercostal space, with a matching pair of surface electrodes. Ventilation, PARA activity from implanted wires, and surface estimated activity were recorded while seated: 1) during rest and hypercapnia, 2) during apnoea with extraneous upper chest wall movement.Results: During resting breathing, we found significant variability in surface EMG estimate versus implanted wire EMG. During hypercapnia, surface estimate diverged significantly away from implanted PARA EMG (slope 3.27 vs 1.30; P<0.05;N=7). During quiet breathing with any chest wall movement, surface estimate EMG appeared unreliable. With voluntary apnoea and chest wall movement, surface EMG estimate showed “pseudobreathing” activity while PARA fine wire was silent[fig.1 ].Conclusion: As an estimate of parasternal intercostal muscle activity, surface EMG has significant challenges that may constrain use in clinical applications.