基于体表生理信号的呼吸功能监测仪研制  

Design of a respiratory function monitor based on surface physiological signals

作　　者：宋鑫 李韵池 张伟光 李永勤 SONG Xin;LI Yunchi;ZHANG Weiguang;LI Yongqin(Department of Biomedical Engineering and Imaging Medicine,Army Medical University,Chongqing 400038,China;Department of Critical Care Medicine,the First Affiliated Hospital of Army Medical University,Chongqing 400038,China)

机构地区：[1]陆军军医大学生物医学工程与影像医学系,重庆400038 [2]陆军军医大学第一附属医院重症医学科,重庆400038

出　　处：《中国医学物理学杂志》2023年第3期353-360,共8页Chinese Journal of Medical Physics

基　　金：国家重点研发计划(2021YFC0122404)。

摘　　要：目的:研制一款基于体表心电、膈肌电和胸阻抗信号的呼吸功能监测仪原理样机,可在家庭、医疗急救等场合实现对呼吸功能的持续监测。方法:以STM32F411VET6单片机开发系统为平台,用一对Ag/AgCl电极作为高频激励信号的输出和心电、胸阻抗信号的检测电极,另一对Ag/AgCl电极作为膈肌电信号检测电极,两对电极同时检测心电、膈肌电和胸阻抗信号。系统硬件主要包括心电信号检测电路、胸阻抗信号检测电路、膈肌电信号检测电路、恒流源激励电路以及微控制器。系统采用12 V可充电锂电池供电,模拟信号通过单片机A/D转换成数字信号,通过SDIO接口存储于SD卡。在完成样机制作和性能测试之后,采集13例因呼吸功能障碍实施机械通气患者和13例健康成年人的信号,计算15个与呼吸功能相关的参数,比较机械通气患者与健康对照组参数之间的差异,验证了呼吸功能监测仪的可靠性。结果:样机采集信号的信噪比>10 dB、共模抑制比>80 dB,样机漏电流<30μA。机械通气患者的吸气时间、呼气时间、潮气量、胸阻抗峰峰值、胸阻抗1 s变化量、膈肌电低频功率、膈肌电高频功率、高频比低频、膈肌放电面积、膈肌放电时间、膈肌电峰峰值和心肺耦合指数值均显著小于健康对照组(P<0.05);机械通气患者心率显著高于健康对照组(P<0.05);两组的呼吸率、吸呼比无显著差异(P>0.05)。结论:本呼吸功能监测仪样机有较高的安全和工作性能,可用于对呼吸功能的实时连续无创监测。Objective To design a principle prototype of respiratory function monitor based on surface electrocardiography(ECG)signals,diaphragm electromyography(DiEMG)signals and thoracic impedance signals that can continuously monitor the respiratory function at home,medical emergency and other occasions.Methods With the STM32F411VET6 microcontroller system as platform,a pair of Ag/AgCl electrodes was used as the output electrodes of high-frequency excitation signals,and the detection electrodes of ECG signals and thoracic impedance signals,while another pair of Ag/AgCl electrodes was adopted to detect the DiEMG signals.The simultaneous detection of ECG signals,DiEMG signals and thoracic impedance signals was realized using the two pairs of Ag/AgCl electrodes.The system hardware mainly included ECG signal detection circuit,thoracic impedance signal detection circuit,DiEMG signal detection circuit,constant current source excitation circuit and microcontroller.The system was powered by the rechargeable lithium battery of 12 V.The analog signals were digitalized by the A/D mode of MCU,and the digitalized signals were stored in SD memory card through the secure digital input and output protocol.After completing the prototype design and performance test,the signals of 13 patients in mechanical ventilation due to respiratory dysfunction and 13 healthy adults were collected,and 15 respiratory function parameters were calculated for comparing the differences between mechanically ventilated patients and healthy controls,thereby verifying the reliability of the respiratory function monitor.Results The signal-to-noise ratio and common mode rejection ratio of the signal acquired by the prototype were>10 dB and>80 dB,and the leakage current of the prototype was<30μA.The following parameters in mechanically ventilated patients were lower than those in healthy adults:inspiratory time,expiratory time,tidal volume,peak-to-peak value of thoracic impedance signal,variation of thoracic impedance signal in 1 s,low-frequency(LF)and high-freque

关 键 词：膈肌电 心电 胸阻抗 呼吸功能监测 原理样机 

分 类 号：R318.6[医药卫生—生物医学工程]