Patent ID: 8459255

Claim:
A respiratory muscle training device comprising a body portion ( 23 ) and a separable mouthpiece portion ( 25 ), the mouthpiece portion including: a chamber ( 1 ) containing a variable orifice valve assembly ( 3 ); an inlet ( 9 ) at a first side of the valve assembly permitting air to be inhaled into the chamber; and an outlet ( 11 ) at a second side of the valve assembly permitting air that has passed through the valve assembly to be inhaled by a user, and the body portion including: a pressure sensor ( 7 ) for determining a pressure differential across the valve assembly; means for determining the opening area of the valve assembly; and control means ( 15 , 47 , 49 ) including an actuator ( 49 ) for varying the orifice of the valve assembly of the mouthpiece portion ( 25 ) in dependence upon a pressure differential determined by the pressure sensor and upon an opening area of the valve assembly.