RESISTIVE ELEMENT AND CALIBRATED AIR TUBE FOR SPIROMETER

摘要

The present air tube, preferably calibrated air tube, includes resistive element (22) which is located in the hollow space of the tubular portion (12). This resistive element (22) is adapted for providing a linear resistance versus pressure response, and is sized and adapted to cause a pressure difference or differential as air flows in the hollow space across this element. The preferred calibrated air tube has a pressure response, is useful in a spirometer, and includes a tubular member. Calibration information is associated with the air tube to a model pressure response of a model air tube having substantially the same dimensions and configurations as the air tube.