Patent ID: 6532956
Filing Date: 2003-03-18
Classification: A61M

Abstract:
A patient treatment system comprising:gas flow generating means for providing a flow of breathing gas to an airway of a patient; pressure controlling means, associated with the gas flow generating means, for controlling a pressure of breathing gas provided to an airway of such a patient; sensing means for detecting an instantaneous flow rate V and an instantaneous volume V of the flow of breathing gas provided to such a patient; and processing means, associated with the sensing means and the pressure controlling means, for controlling the pressure controlling means such that the flow of breathing gas is provided to such a patient at a pressure in accordance with the following relation: Ppatient=R1(t){[R2(t)*(% Set)]*[((R3(t)*(FA)({dot over (V)}))+(R4(t)*(VA)(V))]+R5(t)*EPAP}, where Ppatient is the pressure at an airway of such a patient, % Set is a multiplier, FA is a flow assist multiplier, VA is a volume assist multiplier, EPAP is an expiratory positive airway pressure, and R1(t), R2(t), R3(t), R4(t), and R5(t) are time-based parameter variation functions, and where at least one parameter variation function R1(t), R2(t), R3(t), R4(t), and R5(t) is a function other than a unity function.