SPIROMETER BREATHING TUBE WITH COMPOUND MEMBRANE

摘要

A compound membrane breathing tube for use in spirometric applications is provided. The compound membrane comprises a first sheet and a second sheet of flexible sheeting connected together along the periphery thereof, and each of the sheets has an opening cut therethrough to create a flap. The flap of the first sheet overlaps the flap of the second sheet so as to present a higher relative resistance to airflow through the breathing tube at lower airflows.