Accelerometer based system for continuous respiratory rate monitoring

Recent advances in sensor technologies, wireless connectivity, cloud storage and availability of compact hardware allow for designing of cost effective physiological monitoring devices. There is a growing demand for wearable technologies with continuous and minimally intrusive physiological parameter monitoring capabilities. Continuous respiratory rate monitoring using a three-axis accelerometer from the sternum or abdomen is highly challenging due to motion corruption and presents a potential area of research. A system design for continuous and long term respiratory rate monitoring, in a wearable form factor with capability of remote monitoring is presented in this paper. The device runs on a low power ARM Cortex M0 microcontroller and uses inbuilt BLE (Bluetooth Low energy) module for wireless connectivity. A respiratory rate computation algorithm using motion artifact rejection is implemented on the device for reliable performance. Respiratory rate computation by the device was validated in a controlled setting, against gas pressure sensor on 20 subjects. The system architecture, device design, algorithm implementation and experimental validation of the proposed modality are presented.