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AssigneeResMed Limited
InventorDavid Bassin
Estimating the term…
A method and apparatus for providing ventilatory assistance to a spontaneously breathing patient An error signal (56) is computed that is the difference between a function of respiratory airflow (54) over a period of time and a target value (52). Using a servo loop, air is delivered to the patient at a pressure that is a function of the error signal, the phase of the current breathing cycle, and a loop gain that varies depending on the magnitude of the error signal. The loop gain increases with the magnitude of the error signal, and the gain is greater for error signals below a ventilation target than for error signals above the ventilation target value. The target value (52) is an alveolar ventilation that takes into account the patient's physiologic dead space.
1-111. (canceled)
Apparatus for providing ventilatory assistance to a patient comprising a control mechanism for deriving two error signals each of which is a function of the same target value and a respective one of two patient ventilation measures, the two patient ventilation measures having respective relatively fast and relatively slow speeds of response, said control mechanism further deriving two control responses to respective ones of said two error signals and combining said two control responses to produce an overall control response that increasingly favors the control response to the error signal that is a function of the ventilation measure with the faster speed of response over the control response to the error signal that is a function of the ventilation measure with the slower speed of response as the ventilation measure with the faster speed of response becomes increasingly less than said target value;
Dependencies are inferred from the claim text.