Patent ID: 8869795

Claim:
Apparatus for providing ventilatory pressure support to a patient comprising a control mechanism configured to: obtain a first ventilation measure with a first speed of response and a second ventilation measure with a second speed of response, the first speed of response being faster than the second speed of response, the ventilation measures being derived from respiratory flow of the patient, the second ventilation measure derived by low pass filtering; derive a first calculated error being a function of a target ventilation value and the first ventilation measure, and a second calculated error being a function of the target ventilation value and the second ventilation measure, and calculate a control response based on the first calculated error and the second calculated error, wherein said control response is increasingly dependent on the first calculated error and less dependent on the second calculated error, as the first ventilation measure becomes increasingly less than said target ventilation value; and a ventilator responsive to said control response for controlling the level of pressure of air delivered to said patient.