Development of Smart Textiles for Self-Monitoring Blood Glucose by Using Optical Fiber Sensor

Uninterrupted vital-sign monitoring is one of the application field of the so-called “smart textiles”from the increasing demand for health care demands. Most of the so-called smart textiles have been employed conductive fibers for sensing and signal transformation, but very few employed fiber Bragg grating (FBG) sensor, which can be used as “multi vital sign sensor”. Although the demands for blood glucose monitoring is increasing, no smart textile has been investigated from the viewpoint. We demonstrated at the first time in this paper that FBG sensor could sense blood glucose level and could be expected manner in the textile form. We installed the FBG sensor on the subjectʼs wrist and measured pulse wave. The subject had a meal as a glucose load during the measurement. As pulse wave pattern data from FBG sensor system includes information about several other vital signs, we isolated blood glucose information by using hierarchical neural network analysis. The isolated data provided a calibration curve with an extremely high correlation coefficient to the blood glucose. The calculated values are evaluated by dedicated indicator, and we found there are only small error which we can ignore clinically. Comparing with the former studies, we efficiently achieved feature extraction, and the stability of measurement was improved. Although the result represents the first successful method for realizing more accurate non-invasive blood glucose measurement systems aim to smart textile, this result is good enough even at this stage, and we are expecting for practical use in near future. The successful results lead the development of smart textiles for the uninterrupted non-invasive measurement.