The Myotest is a new nerve stimulator which can give train-of-four, single twitch (1 and 10 s) and tetanic stimuli. Power is supplied by standard batteries, which allow 200 h effective use. The impulse is unipolar constant current, and the amplitude can be adjusted between 0-40 mA. These factors, plus the electronic control of stimulus administrations, make the nerve stimulator easy to use and facilitate the interpretation of responses, especially to tetanic and post-tetanic stimulation.