TY - JOUR T1 - Limitations of superficial EMG estimate of parasternal intercostal muscle activity JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/1393003.congress-2017.PA1866 VL - 50 IS - suppl 61 SP - PA1866 AU - Giovanni Tagliabue AU - Micheal Ji AU - Jenny Jagers AU - Devin Dean AU - Eric Wilde AU - Paul Easton Y1 - 2017/09/01 UR - http://erj.ersjournals.com/content/50/suppl_61/PA1866.abstract N2 - 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. ER -