Supplemental Figure S1

Physiological signals recorded using the RA-16 system. From top to bottom, traces show diaphragm electromyogram (EMGdi), airflow, oxygen saturation (SpO2), heart rate, and end-tidal carbon dioxide (ETCO2). ETCO2 remained stable during inhalation of 3.5% CO2 and returned promptly to baseline after resuming room-air breathing.