Respiratory function efficiency measuring appts. for medical and competition purposes

摘要

The device includes hollow body (2) presenting a window (38) to a vertical slot (10) through which passes a finger (28) attached to a piston moving inside the body on a central, vertical supporting rod (21). A cursor (27) attached to the finger moves against a graduated scale (43) to display the maximum excursion of the piston. The cursor (27) is designed with internal and external thickness wider than the slot in which it rides. A locking piece (4) prevents access to the cursor after assembly in the window so that the cursor cannot be removed.