Patent ID: 6318365
Filing Date: 2001-11-20
Classification: A61M

Abstract:
A method for changing to the inhalation or exhalation phase (T.sub.I and T.sub.E, respectively) with a Cdevice, during a Ctherapy of a patient, the steps comprising:differentiating a respiratory gas flow (V) from and to the patient with respect to time;changing to a respective breathing phase (i.e. inhalation or exhalation) wherein after changing to a respective breathing phase;comparing a first derivative (dV/dt) of the gas flow (V) with a first, high threshold value (HS.sub.E, HS.sub.I)and then a second, low threshold (NS.sub.E, NS.sub.I) for a variation of the first threshold;changing to a respective other breathing phase occurs when the first derivative has reached the second threshold value (NS.sub.E, NS.sub.I);comparing the first derivative with the second, low threshold value (NS.sub.E) in the exhalation phase;sampling a time history of the respiratory gas flow (V) in a sequence of at least three sampling values (X.sub.1, X.sub.2 X.sub.3);changing to the inhalation phase at X.sub.3 if the following two conditionsX.sub.1 +.DELTA.<X.sub.2 and X.sub.2 +.DELTA.<X.sub.3.DELTA.=predetermined incrementare fulfilled, unless the change has already occurred earlier on account of the comparison of the first derivative with the low threshold value (NS.sub.E).