Abstract: An implantable medical device system is described including an implantable medical device for implantation in a patient. One embodiment of the implantable medical device includes a therapy component for providing a therapy to the patient, a minute ventilation (MV) sensing circuit producing MV values indicative of a MV of the patient at time intervals, and computational circuitry. The computational circuitry receives a number of the MV values over a period of time, calculates a statistical parameter (e.g., a mean) of the MV values, and calculates a deviation of the MV values from the statistical parameter (e.g., a standard deviation of the MV values). The computational circuitry detects an onset of sleep in the patient when the deviation of the MV values from the statistical parameter is less than a predetermined MV threshold value, and signals the therapy component to modify the therapy when the onset of sleep is detected in the patient.

Abstract: Methods for improving detection of arrhythmias by adaptively increasing arrhythmia detection intervals. One method includes increasing the V2V, the overall cardiac cycle length, thereby decreasing the pacing rate in the presence of ventricular safety paces (VSPs). Another method includes shortening the trigger interval following the atrial pace event, during which time the pacemaker will detect V-sense events, while leaving the A2V VSP interval unchanged, at the end of which any required VSP will be generated. In yet another method, the interval from A-pace to V-pace, the PAV interval, is shortened, while leaving the overall V2V cycle interval unchanged. This increases the ventricular to artial V2A interval, increasing the detection window for arthythmias. The PAV interval can be shortened in response to a recent history of VSP events.