Wearable Passive Wireless MEMS Respiration Sensor

In this study a passive sensor that wirelessly monitors the profile of the human respiratory system is presented. The sensor was designed to be wearable, weighs less than 10 grams and is durable. The sensor is made of a RF piezoelectric MEMS resonator and an ultra-high frequency antenna made of a thin metal film formed on a flexible substrate . The resonance frequency of the TPoS resonator shifts as a function of condensation and evaporation of water vapor on the surface of the resonator and changes in resonator\u27s temperature. These parameters change in each in response to inspiration and expiration and a wireless measurement system detects the frequency shift of the sensor and converts it into the respiration profile. The respiration profile of a healthy human subject is measured and presented for a transmitter to sensor to receiver distance of ~25cm