Catheter flow sensor with temperature compensation for tracheal intubation tube system

A micro-electro-mechanical systems catheter flow sensor was integrated into the tracheal intubation tube system to prevent the insertion of the tube into the esophagus. A temperature sensing mechanism was integrated into the catheter flow sensor to compensate for the temperature change in air during flow-rate measurement, and the sensor was placed on the inside the slip joint by using an adapter produced using a molding process. The relationship between the sensor output and flow rate was evaluated, and closely matched sensor outputs for both the forward and backward flows were obtained. The tracheal tube in the modified system was inserted into the air passage of a rabbit, and the air flow passing through the tube was directly measured using the integrated catheter flow sensor in real time. By adding the temperature compensation mechanism, the volumes of the expired- and inspired-air almost matched. We believe that a doctor will easily be able to evaluate whether the tube is inserted into the bronchi or the esophagus when using the modified system.