The anesthesia and brain monitor (ABM). Concept and performance.

Three integral components of the ABM, the frontalis electromyogram (EMG), the processed unipolar electroencephalogram (EEG) and the neuromuscular transmission monitor (NMT) were compared with standard research methods, and their clinical utility indicated. The EMG was compared with the method of Dundee et al (2) for measuring the induction dose of thiopentone; the EEG was compared with the SLE Galileo E8-b and the NMT was compared with the Medelec MS6. In each case correlation of results was extremely high, and the ABM offered some advantages over the standard research methods. We conclude that each of the integral units of the ABM is simple to apply and interpret, yet as accurate as standard apparatus used for research. In addition the ABM offers excellent display and recording facilities and alarm systems.