Measurement of electroconvulsive shock Intensity

This paper discusses the error introduced in administering ECS by calibrating intensity on the S’s dc rather than ac resistance. Since the ac resistance of rats and mice can be lower than their corresponding dc resistance by a factor of 50, calibrating on dc resistance can introduce appreciable error depending on the current regulation of the ECS device. Examples are included to illustrate the range of possible error. In addition, an alternative method for measuring ECS intensity is presented that greatly reduces measurement error including those due to between-animal resistance differences that necessarily occur when using the usual methods.