Development of a high resolution human breath gas sensor considering application for rescue robotics in disaster zones

This paper presents a new type of ultrasonic gas molecule concentration sensor for rescue robotics. This devise can measure the change of the gas concentration with a sampling rate of over 400 kHz. The performance of developed sensor is investigated by applying as human breath gas measurement sensor. Ideal gas experiment results show that the proposed sensor could detect the difference between 5% CO₂ and pure air over 50 dB S/N and could discriminate humidified air and pure air with 55 dB S/N. Another important result is that our proposed respiratory sensor could detect ”dead space” information distributed from lungs to mouth, which could not be detect by previously proposed commercial use gas concentration sensors. Therefore, it is highly probable that this sensor can detect in a very short time a small-difference of molecular gas change of survivors in the disaster zones.