MOUTHPIECE FOR USE IN A SPIROMETER

摘要

The invention entails a mouthpiece for use in a spirometer. In one embodiment of the invention, the mouthpiece comprises a tube forming a conduit between an upstream end and a substantially closed downstream end. An opening is formed through the tube and is proximate to the downstream end of the tube. The mouthpiece also comprises a resistive element that is positioned substantially across the tube opening. In addition, the mouthpiece comprises an outer sleeve that is slide along the exterior of the tube. The outer sleeve may be slid along the tube thereby covering portions of the tube opening in varying amounts. Thus, the outer sleeve may be slid into one position wherein the tube opening is uncovered. The outer sleeve may then be advanced into a closed position wherein the tube opening is substantially sealed. Many partially closed positions exist between the open and closed positions thereby allowing for variable amounts of resistance to air flow. To clearly indicate to the user how far the outer sleeve has been advanced, markings may be made on the outer sleeve or tube indicating, for example, the first tube opening is fifty percent occluded.