Patent ID: 7395115

Claim:
An active implantable medical device, comprising: means for measuring a respiratory activity of a patient having an output signal corresponding to ventilatory activity of the patient; means for analyzing the output signal of ventilatory activity and determining at regular intervals a measure of ventilatory activity; means for calculating a first sliding average of a first number of ventilatory activity measures; means for calculating a second sliding average of a second number of ventilatory activity measures, the second number of ventilatory activity measures being consecutive to said first number of ventilatory activity measures; means for determining a difference between the first and second sliding averages; means for detecting an occurrence of a hypopnea in response to said difference between the first and second sliding averages being between 50% and 100%; means for delivering cardiac stimulation pulses at a stimulation rate; means for modifying said stimulation rate, including means for increasing said stimulation rate in response to a first detected hypopnea; and means for detecting a phase of patient activity including an awakening phase and a sleep phase and a transition between said sleep and awakening phases, wherein the analyzing means further comprises means for comparing a modification of said stimulation rate and a detected transition from a sleep phase to an awakening phase and means for determining a correlation between said modification and said transitions and providing a correlation indicator indicative of a correlation between a modification of the operating parameter and consecutive transitions from a sleep phase to an awakening phase, and for delivering said correlation indicator in the event of a determined correlation.