High resolution wearable FBG-based sensing device for cardiac rate and blood pressure monitoring

This study introduces a method for monitoring cardiac rate and blood pressure using fiber Bragg grating (FBG) sensors. A custom FBG array with two multiplexed sensors was developed to measure pulse waves at different body locations. The FBG sensors detect cardiac rate by capturing pulse vibrations, while blood pressure is inferred from the pulse wave signals. Variations in systolic blood pressure affect the time required for a single pulse wave to travel between two body sites. By calibrating the time difference of pulse waves at different locations with systolic pressure, blood pressure can be accurately estimated. The device enables real-time cardiovascular monitoring with a 5 kHz sampling rate. Experimental results demonstrate a correlation coefficient of 0.65 between predicted and actual systolic blood pressure, with a standard error of 4 mmHg. Compared to traditional sensing devices, this FBG-based system is more compact, offers higher resolution, and provides faster response times.