Low-power contactless LC-tank based respiratory sensor

In this Letter, a novel approach for contactless, low-cost and low-power respiratory sensing is presented, which is based on a commercial LC tank. This sensor is able to measure the variation of losses of induced eddy currents during one respiration period. The developed sensor system can be used in multiple different application fields where low-cost and low-power respiratory sensing is necessary. Examples for that can be infant or patient beds where vital parameters have to be monitored or in other fields where contactless presence check is desired. At first, the theory of operation and requirements for the respiratory sensing applications are explained which is followed by the system design and measurement results.