Patent ID: 6739336
Filing Date: 2004-05-25
Classification: A61M

Abstract:
A feedback controller for regulating respiratory gas in a mechanical breathing assist apparatus, said feedback controller comprising:a measurement unit which measures a value of a gas parameter associated with respiratory gas; a comparator supplied with said value of said gas parameter, and with a target value for said gas parameter, said comparator periodically generating, in a current breathing cycle, an error signal representing a difference between said value of said gas parameter and said target value of said gas parameter; a control signal generator supplied with said error signal for processing said error signal using a control function having a control parameter with a variable value, to generate a control signal for regulating said respiratory gas; and an adaptation unit connected to said control signal generator for varying said value of said control parameter dependent on said error signal, by determining, for said current breathing cycle, an extreme value of said error signal and for varying said value of said control parameter for a next breathing cycle dependent on a rate of change of said extreme error signal relative to said value of said control parameter in said current breathing cycle.