Method and apparatus for determining a respiration parameter in a medical device

A method of determining a respiration parameter in a medical device, comprising:

• sensing pressure signals to generate corresponding sample points;
• continuously adjusting a breath detection threshold in response to a minimum amplitude of a predetermined number of the generated sample points to generate a first detection threshold;
• determining whether a current generated sample point is less than the first inspiration detection threshold;
• suspending the continuous adjusting of the breath detection threshold and setting the first respiration detection threshold equal to the most current adjusted breath detection threshold generated prior to the suspending;
• determining whether a first predetermined number of next sample points, generated subsequent to the suspending, is less than the first respiration detection threshold;
• resuming the continuous adjusting of the breath detection threshold to continuously adjust the breath detection threshold in response to a maximum amplitude of the generated sample points to generate a second respiration detection threshold;
• determining whether a current generated sample point is greater than the second respiration detection threshold;
• suspending the continuous adjusting of the breath detection threshold and setting the expiration detection threshold equal to the most current adjusted breath detection threshold generated prior to the suspending;
• determining whether a second predetermined number of next sample points, generated subsequent to the suspending, is greater than the second respiration detection threshold;
• and
• determining the respiration parameter in response to the predetermined number of next sample points being greater than the second respiration detection threshold.