Inspiratory force adaptor

Claim 1

An inspiratory force adapter comprising: (a) an elongated hollow tubular body member having first and second ends and an air passage extending therethrough adapted to be grasped between the thumb and a finger of an operator; (b) said tubular body being provided with a finger port adapted to be closed by an index finger of said operator; said finger port constituting an opening from said air passage to the outside atmosphere; (c) the exterior of said tubular body member being provided with opposing finger positioning surfaces, the first of said surfaces being a thumb locating surface adapted to be engaged by the side of the thumb of said operator and the second of said surfaces being a finger locating surface adapted to be engaged by the side of said first named finger; the perpendicular central axes of said surfaces being aligned, with respect to each other and being transverse to the longitudinal axis of said body member, a ridge encircling said body member and abutting said surfaces, said surfaces being located along the peripheral surface of said body member between said first end and said ridge, said ridge being disposed with its transverse plane being oriented at an angle with respect to said perpendicular central axes of said surfaces, such that the difference between the distance from the ridge to said central axis of the thumb locating surface and the distance from the ridge to said central axis of said finger locating surface is substantially one tenth of an inch, said finger port being located on said tubular body member between said ridge and said second end and opposite said thumb locating surface.