Textile Fiber Optic Microbend Sensor Used for Heartbeat and Respiration Monitoring

This paper reports on a textile fiber optic microbend sensor for heartbeat and respiration monitoring. A section of multimode optical fiber sandwiched between parallel strips acting as a microbender is being integrated onto an elastic substrate. Its design is based on fiber microbending effects. The textile sensor can be used to measure heartbeat and respiration rate simultaneously during standing and sitting position. The detected heart rates from our sensor are in good agreement with that from the commercial SpO2, whereas the respiration rate is verified by counting the breathing manually. We characterize the frequency response of the sensor with a simulation setup and find that the sensitivity of the sensor is large enough at 105 r/min although it decreases with the increase of the motor speed. The textile fiber optic sensor is very comfortable to wear due to the elastic nature of the substrate.