基于双电极的微型心功能监测仪的研制

发布时间：2018-01-05 18:41

本文关键词：基于双电极的微型心功能监测仪的研制　出处：《中国医学物理学杂志》2015年06期 　论文类型：期刊论文

【摘要】：目的:研制一款基于双电极的微型心功能监测仪,可在家庭、社区、急救等场合实现对患者心功能的持续监测。方法:以MSP430单片机开发系统为平台,用一对监护/除颤电极作为高频激励的输入和心电、胸阻抗信号的检测电极,同步检测心电和胸阻抗信号。系统硬件主要包括电源模块、恒流源激励电路、心电信号检测电路、胸阻抗信号检测电路、微处理器控制电路、LCD显示模块以及数据存储模块。系统采用5 V可充电锂电池供电;激励源采用1 MHz/1 m A正弦波恒流源;心电信号检测电路由前置放大、带通滤波、50 Hz陷波和后级放大等电路构成;由电极两端检测的胸阻抗信号在经过滤波、解调、微分和放大以后,最终获得基础阻抗、交流阻抗和阻抗微分信号。模拟信号通过单片机的A/D接口转换成数字信号,通过指定的端口送入液晶屏实时显示并存储于SD卡。在完成样机设计和性能测试之后,采集了14例心血管疾病患者和7例同龄对照组健康人群的心电信号和胸阻抗信号,通过上位机应用程序对采集的数据进行分析,计算了心率、基础阻抗值、阻抗微分信号的峰值、峰谷值和左室射血期的曲线面积。首先比较了心功能异常患者与正常对照组之间胸阻抗信号各特征值之间的差异,然后结合超声检查结果分析了心血管疾病患者胸阻抗信号的特征值与左心室收缩功能之间的相关性。结果:样机尺寸为200 mm×120 mm×110 mm,输入额定功率为5 W。心功能异常患者的阻抗微分信号的峰值显著小于同龄对照组(P=0.007),其左室射血期曲线下的面积也显著小于对照组(P=0.012);患者的阻抗微分信号的峰值和左室射血期曲线下的面积与左心室射血分数均具有显著相关性,相关系数分别为r=0.811(P0.001)、r=0.905(P0.001)。结论:基于双电极的微型心功能监测仪具有轻巧便携、操作简单、工作安全可靠的特点,不仅能够定性地反映左心室收缩功能,而且能够定量地描述心功能异常。
[Abstract]:Objective: to develop a micro heart function monitor based on double electrodes, in the family, community, first aid and other occasions to achieve sustained monitoring on the cardiac function of the patients. Methods: using MSP430 microcontroller development system as the platform, using a pair of monitoring / defibrillation electrode as excitation input and high frequency ECG, chest impedance signal detection electrode. Simultaneous detection of ECG and chest impedance signals. The hardware system includes power supply module, constant current source circuit, the ECG signal detection circuit, the impedance signal detection circuit, a microprocessor control circuit, LCD display module and data storage module. The system uses 5 V rechargeable lithium battery; excitation source with 1 MHz/1 m A sine wave constant current source; ECG signal detection circuit is composed of preamplifier, band-pass filter, 50 Hz notch filter and amplifier circuits; from the thoracic impedance signal at both ends of the electrode in detection of filtering wave, differential demodulation, and Later, finally get the foundation impedance, AC impedance and impedance differential signal. Analog signals into digital signals through the A/D interface of MCU, through the designated port into the LCD real-time display and stored in the SD card. After completing the prototype design and performance test, collected 14 cases of patients with cardiovascular disease and 7 normal ECG signals and the impedance signal control group of healthy people, through the analysis of the application of PC on the collected data, the heart rate was calculated, the foundation impedance value, peak impedance differential signals, peak valley value curve area and left ventricular ejection period. Firstly, compares the difference between abnormal heart function in patients with normal control group thoracic impedance the signal characteristic value, and then combined with the ultrasound results analyzed the characteristics of thoracic impedance signals of patients with cardiovascular disease and the correlation between the value of left ventricular systolic function. Results: Prototype The size of 200 mm * 120 mm * 110 mm, rated power input peak impedance differential signals in patients with abnormal cardiac function of 5 W. were significantly less than normal group (P=0.007), the left ventricular ejection period in the area under the curve was also less than the control group (P=0.012); and the area of the left ventricular ejection fraction and peak left ventricular ejection time curve of impedance differential signals were under significant correlation, the correlation coefficient was r=0.811 (P0.001), r=0.905 (P0.001). Conclusion: Micro heart function monitor based on two electrodes is lightweight and portable, simple operation, safe operation, not only can qualitatively reflect left ventricular the systolic function, and can quantitatively describe the abnormal cardiac function.

【作者单位】：重庆大学生物工程学院;第三军医大学生物医学工程学院;第三军医大学附属西南医院心内科;
【基金】：重庆市自然科学基金(CSTC2010BB5023) 教育部高等学校全国优秀博士学位论文作者专项资金(201060)
【分类号】：TH789
【正文快照】： 科,重庆400038随着社会的发展,心血管疾病已经成为对人类健康威胁最严重的疾病之一。据统计,我国心血管疾病的患者约为2.9亿人口,而每年死于心血管疾病的人数达350万,约占每年总死亡人数的40%[1]。心脏功能的正常发挥有赖于正常的心电活动和心脏舒缩运动。心血管疾病会引起心

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