Body temperature measurement based on breathing airflow for continuous monitoring of patient body condition during large scale disasters

Continuously monitoring a patient body condition during large scale disasters requires vital information to be acquired quickly and easily to aid medical professionals. Breathing airflow, especially exhaled airflow, contains not only respiration but also body temperature information. Thus, a body temperature measurement method using exhaled airflow was proposed, and a temperature sensor was implemented into a thermal-type breathing airflow sensor to detect both respiration and body temperature information from breathing airflow alone. Both sensors were designed and fabricated by MEMS technologies. The temperature sensor operated with an input power of less than 0.5 mW to prevent self-heating, and we confirmed it can detect the air temperature with an accuracy of less than 1.0 °C under different temperature airflow conditions. The effects of the thermal airflow sensor on temperature measurements were also experimentally evaluated, and we concluded that the developed sensor can measure the airflow temperature with an accuracy of less than 0.5 °C. Finally, the developed sensors successfully detected periodical temperature changes in the airflow, mimicking human breathing.