Patent ID: 8112148

Claim:
A medical device system comprising: a brain monitoring element for sensing activity of a brain of a patient and outputting a brain signal; a cardiac monitoring element for sensing activity of a heart of the patient and outputting a cardiac signal; and one or more processors configured to communicate with the brain monitoring element and the cardiac monitoring element, the one or more processors configured to: receive the brain signal; identify one or more brain events in the brain signal, each of the brain events having a start time and an end time defining a brain event time period; receive the cardiac signal and store cardiac signal information in one or more data buffers; identify one or more Inter-event portions of the cardiac signal, each of the one or more Inter-event portions corresponding in time to a period that is not a brain event time period; calculate an Inter-event heart-rate variability (HRV) based on the cardiac signal information stored for the one or more Inter-event portions of the cardiac signal but not based on the cardiac signal information corresponding in time to the brain event time period of each of the one or more identified brain events; and modify an output of the medical device system based upon the Inter-event HRV.