一种基于石英晶体微天平倍频相移信号的呼吸频率监测系统  

Phase Shift Signal of Quartz Crystal Microbalance with 5th Harmonic Frequency for Monitoring Respiratory Rate

作　　者：邓如悦 司士辉[1] 陈金华[2] 王桢昌 贾胜彬 张汶铮 DENG Ruyue;SI Shihui;CHEN Jinhua;WANG Zhenchang;JIA Shengbin;ZHANG Wenzheng(College of Chemistry and Chemical Engineering,Central South University,Changsha Hu’nan 410083,China;State Key Laboratory of Chemo-Biosensing and Metrology,Hunan University,Changsha Hu’nan 410082,China)

机构地区：[1]中南大学化学化工学院,湖南长沙410083 [2]湖南大学化学生物传感与计量学国家重点实验室,湖南长沙410082

出　　处：《传感技术学报》2024年第6期1078-1083,共6页Chinese Journal of Sensors and Actuators

摘　　要：对人体呼吸频率实时连续的监测具有重要的医学诊断价值,本研究以基频10 MHz压电石英晶体为呼吸监测传感元件,采用直接数字频率合成器(DDS)合成频率源在5倍频下激励压电石英体,实时连续测定呼吸气流下的压电石英晶体相移变化信号。由于高倍频下压电石英体对表面水分子吸附聚集过程具有高灵敏的质量响应,因此石英体表面不需厚膜修饰,直接采用金属电极(银电极)的石英体,成功实现了对呼吸频率的连续监测。与传统的频移法相比,该方法信号采样速度快,可低至0.05 s/点,无论对慢呼吸还是急促呼吸都可以实现准确监测。石英晶体微天平相移呼吸检测系统不仅能够满足连续呼吸监测的要求,还可以为人体呼吸监测提供呼吸频率、呼吸强弱,呼吸紊乱度等呼吸特征信息。Real-time continuous monitoring of human respiratory rate has significant medical diagnostic value,a piezoelectric quartz crystal with a fundamental frequency of 10 MHz is used as a sensing element for respiratory monitoring,in which the direct digital frequency syn-thesizer(DDS)synthetic frequency source is applied to excite the piezoelectric quartz at 5th harmonic frequency and the phase shift of the piezoelectric quartz crystal is continuously measured under respiratory airflow in real time.Due to the sensitive mass response of the piezo-electric quartz to the adsorption and aggregation of water molecules on the surface of the crystal at high frequencies,the continuous monito-ring of respiratory frequency is successfully achieved by direct using a quartz crystal with a metal electrode(silver electrode)without the need for thick film modification on the quartz surface.Compared to the traditional frequency shift method,the proposed method has a fast signal sampling rate of down to 0.05 s/point,allowing for accurate monitoring of both slow and rapid breathing processes.The QCM phase shift respiration detection system not only meets the requirements for continuous respiration monitoring but also provides information on re-spiratory characteristics such as respiratory rate,respiratory strength,and respiratory disturbance for human respiratory monitoring.

关 键 词：石英晶体微天平 传感器 呼吸监测 相位响应 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] R446.9[自动化与计算机技术—控制科学与工程]