Development of Stent Flow Sensor Device Evaluating Breathing Property at Airway in Experimental Animal Under Free Move Condition

A micro-machined flow sensor and a stent were integrated to enable evaluation of the in-situ breathing properties in the air passage of experimental animals. A tube flow sensor that operates on the thermal principle was fabricated using micro-electro-mechanical systems technology, and a newly designed stent structure was fabricated using photolithography and wet etching processes. The fabricated flow sensor and stent were integrated via connection areas formed on both elements. The developed stent flow sensor device was positioned at the center of the tube's cross-section by expanding the stent. The flow rate detection property was evaluated to obtain calibration curves for use in converting the sensor output value into a flow rate waveform. Testing using an artificial ventilator demonstrated that the stent flow sensor device can be placed in the air passage of small animals to detect the breathing airflow directly. A potential application is the development of new drugs.