Apparatus and method for relieving dyspnoea

Abstract

Apparatus for relieving dyspnoea in an ambulatory exercising subject comprises a housing to be worn on the subject, and within which a variable speed air blower motor is located for delivering an air supply to the subject through a mouthpiece at a pressure similar to average intrinsic positive end-expiratory pressure of the subject. A pressure transducer in the mouthpiece monitors the pressure during breathing cycles of the subject, and a control circuit determines the average intrinsic positive end-expiratory pressure of the subject over five breathing cycles. The control circuit operates the air blower motor for delivering the air supply to the subject at a pressure similar to the determined average intrinsic positive end-expiratory pressure.

What is claimed is: 
     
         1 . Apparatus for providing pressure support to a subject, the apparatus comprising:
 a gas flow generating system adapted to provide a flow of gas   monitoring means for monitoring a characteristic associated with a breathing cycle of a subject;   controlling means for controlling the pressure of the flow of gas provided by the gas flow generating system;   a patient circuit having a first end operatively connected to the gas flow generating system and a second end;   a patient interface operatively connected to the second end of the patient circuit; and   an exhaust valve coupled to the patient interface so as to communicate an interior of the patient interface to ambient atmosphere through at least a portion of the patient interface, wherein the exhaust valve is operable under control of the controlling means to control a pressure of the flow of gas in the patient interface.   
     
     
         2 . The apparatus as claimed in  claim 1 , wherein the valve is a pressure regulating valve. 
     
     
         3 . The apparatus as claimed in  claim 1 , wherein the gas flow generating system includes a blower motor, and wherein the controlling means controls the pressure provided by that gas flow generating system by controlling an operating speed of the blower motor.