Patent ID: 7861596

Claim:
A method for detecting airflow within an air containment zone, the method comprising: providing an airflow detecting system at a boundary of the air containment zone; and measuring a parameter of airflow within the air containment zone with the airflow detecting system, wherein the airflow detecting system comprises a structure having an inner surface defining an interior of the tubular structure, one open end and an opposite open end, the tubular structure being configured to receive and expel air through both the one end and the opposite end, a membrane connected to the inner surface of the tubular structure to block the interior of the tubular structure, a flap formed in the membrane, the flap being connected to the membrane by a hinge, the flap being configured to impede airflow within the interior of the tubular structure upon the application of differential pressure across the two ends of the tubular structure, and a device attached to the flap in a position in which the device spans the hinge, the device being configured to measure a parameter associated with the movement of the flap in response to airflow within the interior of the tubular structure.