Verification of Blood Pressure Monitoring System Using Optical Fiber Sensor

The ever-increasing elderly population and soaring medical expenses demand a wearable monitoring system that can continuously administer blood pressure values to prevent and treat diseases. However, a conventional measuring device does not satisfy this demand owing to its large size and the physical pressure exerted during a measurement. To tackle the issue, the development of smart textiles which has a body signal detection function has been widely investigated. We have proposed a wearable, non-invasive blood pressure measurement device using a fiber Bragg grating (FBG) sensor. The FBG sensor can be easily embedded in garments. Therefore, the FBG sensor can be used in smart textiles for wearable blood pressure monitoring. We used the partial least squares regression (PLSR) method for constructing the calibration curve, which was used to estimate the blood pressure values with the pulse wave signals measured by the FBG sensor. In this study, we demonstrated the measurements of suddenly varying blood pressure values by simulating an abrupt blood pressure change using the cold pressor test. The validation that our system can trace sudden blood pressure change is essential to realize the wearable and continuous blood pressure monitoring device. Our system can efficiently predict the changes in the blood pressure values by focusing on the shape difference in the part of the signal measured by FBG sensor, which indicates the pulse wave reflected from the peripheral blood vessel. The accuracy of the proposed FBG sensor-based system is comparable to the conventional blood pressure measurement device. In fact, the system displays better accuracy in the measurement of sudden changes in blood pressure values.