Performance of venturi oxygen delivery devices

The oxygen blenders used in disposable oxygen masks from five manufacturers (Hudson, Inspiron, McGaw, Medishield and Vickers) were tested for delivered oxygen concentration and flow. In all concentration ranges the Medishield and McGaw were more accurate than the others. With some exceptions the flow output of these two devices was also adequate. The Medishield blenders which were tested over a wide range of oxygen inflows proved very stable in their delivered oxygen concentration.