Sensitivity of a single coil electromagnetic sensor for non-contact monitoring of breathing.

We design and analyse a flexible non-contact electromagnetic sensor for monitoring breathing. This paper presents the sensor design and the theoretical model for the expected sensitivity from which we optimize design components. The primary application of this device is in non-invasive sleep monitoring and it has the potential to be useful for detection of both adult and infant apnea. The conductivity changes of the lungs during breathing are monitored by inducing eddy currents within them. The sensor consists of a small coil that acts as both a transmitter and a receiver. The theoretical sensitivity of the sensor to breathing changes is calculated and corresponds within the assumptions of the model to the measured results.