Capacitive sensor for respiratory monitoring

Abstract

Dielectric properties of human lung in chest and diaphragm area are changing during respiratory activity. This process can be monitored measuring capacity of sensor which consists of two or more electrodes attached to the body. A simple device with electrodes for capacitive sensing of respiratory was developed and tested. This capacity was connected to Colpitts oscillator LC circuit and causes frequency change. Two different circuits were tested with the same electrode sets.