Fig. 1. (A ) Bispectral Index (BIS), electromyographic activity (EMG), total power of the signal (TOTPOW), and signal quality index (SQI) trend recordings in a patient who required long-period myorelaxation for adaptation to mechanical ventilation. Administration of myorelaxant induced a significant decrease in both BIS and electromyographic activity. The regular peaks in electromyographic activity and SQI signal activity are linked to regular resets of the BIS® monitor (automatic ground verification). (B ) BIS, electromyographic activity, and SQI trend recordings in a patient who required transitory myorelaxation for facilitation of bronchoscopy. Administration of myorelaxant induced a significant decrease in both BIS and electromyographic activity, which began to recover while the effect of the myorelaxant lessened. (TOTPOW trend recording is not plotted to avoid superimposition of curves.)