Electro Convulsive Therapy (ECT) machine made in the early 1940s by Edison Swan Co. Ltd. to the specifications of W Grey Walter and used at the Burden Neurological Institute. Designed to give an electrical stimulus from the AC mains supply at a voltage varying from 60 to 150 volts, for a short preset period of time of typically 0.2 seconds. Use of this machine was discontinued in the 1970s. Serial no. SS35. Edison Swan labels appear to be apinted over. GRS stamped on one of the electrodes Electroconvulsive therapy machine 1940-1945