Abstract: A method for monitoring the response of a nervous system of a body to a stimulus. The method comprises collecting a set of voltage measurements between selected areas on a surface of the body whilst current is being passed between selected regions of the surface of the body. The set of voltage measurements is collected over a predetermined measurement period, the predetermined measurement period is initiated at a predetermined time after application of the stimulus, and the collected voltage measurements are compared with reference to determine normal or abnormal response of the nervous system.

Abstract: A method for detecting for the presence of a degenerative brain disease such as BSE or CJD. A measurement is made of the respiratory sinus arrhythmia of any mammal which is suspected of suffering from the degenerative brain disease. It is assumed that the mammal is suffering from such a disease if the measured RSA is outside a predetermined reference range. The reference range may be determined from data which forms the basis for the calculation of the RSA range by applying a suitable test for randomness.