The invention provides a device for measuring an inside diameter of a body lumen, such as an air passageway. The device includes a flexible catheter having an inflation lumen, a fluid dispenser in fluid communication with the inflation lumen and operable to communicate a measurable fluid volume change...http://www.google.com/patents/US20040059263?utm_source=gb-gplus-sharePatent US20040059263 - Device and method for measuring the diameter of an air passageway
