Endless Coreless Fiber Sensor Coated with Gold and Graphene for Respiratory Monitoring System

Traditional methods are used to measure respiratory rates. These methods rely on the number of times the chest inflates and contracts. Other methods may be inaccurate or take time. So, based on past and recent research, the optical sensor method is very efficient and real-time sensing. This type of sensor is always the most demanded in current and future research so, we proposed a respiratory monitoring system based on an optical fiber sensor. The sensor consists of coreless fiber spliced with multimode fiber on one side coated with nanogold particles and graphene. The sensitivity and response time of the sensor were calculated with coated gold and with coated with gold & graphene; when coated with gold were 473.2 pm/%RH and 2.3 sec respectively, and when coated with gold & graphene was 513.8 pm/%RH and 1.5 sec respectively. The result showed that when breathing increased, the intensity of light decreased. The sleeping case of breathing has more intensity value than the intensity of working sport value.