Patent ID: 7447541

Claim:
A method for monitoring subcortical responsiveness of a patient, the method comprising the steps of: acquiring at least one first physiological measurement signal from a patient using at least one sensor, the physiological measurement signal being one of the signals in a group including an RRI signal, a plethysmographic signal, an EMG signal, a blood pressure signal, and a signal representing skin conductivity; deriving at least one second measurement signal from the at least one first measurement signal, said at least one second measurement signal being indicative of pain-related activity in the patient; supplying a predetermined stimulus signal to the patient to cause pain to the patient, wherein the predetermined stimulus signal is supplied in synchronization with a spontaneous rhythm of the patient that is regulated by the autonomous nervous system of the patient; monitoring a response caused by the stimulus signal in the at least one second measurement signal, wherein the monitoring step is synchronized with the supplying step; determining, based on the monitoring step, an indicator of subcortical responsiveness, said indicator being indicative of the patient's level of antinociception; and outputting the indicator of subcortical responsiveness to a device.