Fiber Bragg Grating Pulse and Systolic Blood Pressure Measurement System Based on Mach–Zehnder Interferometer

• Published in: Sensors (Basel, Switzerland) Vol. 24; no. 19; p. 6222
• Main Authors: Li, Yuanjun, Wang, Bo, Liu, Shanren, Gao, Mengmeng, Li, Qianhua, Chen, Chao, Guo, Qi, Yu, Yongsen
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.10.2024; MDPI
• Subjects: Blood pressure; Blood Pressure - physiology; Blood Pressure Determination - instrumentation; Blood Pressure Determination - methods; Comparative analysis; Design and construction; edge filter; Equipment Design; fiber Bragg grating; Fiber optics; Field programmable gate arrays; Heart rate; Humans; Humidity; Interferometers; Interferometry; Interferometry - instrumentation; Interferometry - methods; Measurement; Medical equipment; Optical detectors; Optical Fibers; pulse; Pulse Wave Analysis - instrumentation; Pulse Wave Analysis - methods; Sensors; Signal Processing, Computer-Assisted; Signal to noise ratio; Spectrum analysis; systolic blood pressure; Veins & arteries; China; pulse; edge filter; fiber Bragg grating; systolic blood pressure
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s24196222

A fiber Bragg grating (FBG) pulse and systolic blood pressure (SBP) measurement system based on the edge-filtering method is proposed. The edge filter is the Mach–Zehnder interferometer (MZI) fabricated by two fiber couplers with a linear slope of 52.45 dBm/nm. The developed system consists of a broadband light source, an edge filter, fiber Bragg gratings (FBGs), a coarse wavelength-division multiplexer (CWDM), and signal-processing circuits based on a field-programmable gate array (FPGA). It can simultaneously measure pulse pulsations of the radial artery in the wrist at three positions: Cun, Guan and Chi. The SBP can be calculated based on the pulse transit time (PTT) principle. The measurement results compared to a standard blood pressure monitor showed the mean absolute error (MAE) and standard deviation (STD) of the SBP were 0.93 ± 3.13 mmHg. The system meets the requirements of the Association for the Advancement of Medical Instrumentation (AAMI) equipment standards. The proposed system can achieve continuous real-time measurement of pulse and SBP and has the advantages of fast detection speed, stable performance, and no compression sensation for subjects. The system has important application value in the fields of human health monitoring and medical device development.