In-fiber Mach-Zehnder interferometer for wearable respiration measurement

An in-fiber Mach-Zehnder interferometer based on single-mode fiberup-tapermultimode fiberup-tapersingle-mode fiber structure for respiration measurement is presented. The sensor probe is imbedded in a textile belt and fixed on the individual’s abdomen as a wearable solution. The system is used to detect the respiration rate of six volunteers, the respiration under different states is experimentally investigated. Attribute to the robust structural design and signal demodulation technique, the interference of temperature and body movement is reduced and the measurement accuracy and stability is distinctly improved. This simple, high accuracy, cost-effective wearable respiration sensor has great potential in real-time respiration monitoring.