Methods, systems and / or apparatus for slowing a patient's
breathing by using
positive pressure therapy. In certain embodiments, a current interim
breathing rate target is set, and periodically the magnitude of a
variable pressure waveform that is scaled to the current interim
breathing rate target is increased if the patient's breathing rate is greater than the interim breathing rate target in order to lengthen the patient's breath duration. The magnitude of the
pressure increase may be a function of the difference between the interim breathing rate target and the patient's breathing rate. The interim breathing rate target may be periodically reduced in response to the patient's breathing rate slowing down toward the current interim breathing rate target. The
variable pressure waveform cycles from an
inhalation phase to an
exhalation phase when the patient
airflow decreases to a
cycle threshold, the
cycle threshold being a function of flow versus time within a breath and generally increasing with time. Different interim breathing rate targets have different
cycle threshold functions, and the cycle threshold functions allow easier
cycling as the interim breathing rate targets decrease. Similarly, the
variable pressure waveform triggers from an
exhalation phase to an
inhalation phase when the patient
airflow increases to a trigger threshold, the trigger threshold being a function of flow versus time within a breath and generally decreasing with time. Different interim breathing rate targets have different trigger threshold functions, and the trigger threshold functions allow easier triggering as the interim breathing rate targets decrease.