Variable transition pressure profiles for a bi-level breathing therapy machine

A method of setting the pressure at which breathing gas is delivered by a breathing therapy device comprising the steps of:

• a. receiving or calculating a first therapy pressure and a second therapy pressure;
• b. predicting a time for transition between said first therapy pressure and said second therapy pressure;
• c. calculating a transition pressure profile to be applied for transitions between said first therapy pressure and said second therapy pressure;
• d. scaling said transition pressure profile to a desired duration, said desired duration starting at a set time prior to said predicted transition time and ending at a set time after said predicted transition time;
• and
• e. modifying said pressure at which said breathing gas is delivered in accordance with said scaled transition pressure profile to transition said pressure from said first therapy pressure to said second therapy pressure.