基于心阻抗法的无创血流动力学监测系统设计与实现

      Design and Implementation of Non-Invasive Hemodynamic Monitoring System Based on Impedance Cardiogram Method

      • 摘要: 血流动力学监测能够反映心功能和血流灌注状况,是临床中不可或缺的监测手段。以热稀释法为代表的有创血流动力学监测方法因为需要进行血管插管,所以其临床应用范围受到限制。无创血流动力学监测由于具有安全无创、可连续监测、操作简单以及成本低等优势,近年来受到国内外医疗企业及临床医生的广泛关注。该文设计了一款基于心阻抗法的无创血流动力学监测系统,涵盖硬件、算法、软件设计以及性能参数评估。其中,硬件部分主要包括差分高频恒流源刺激电路、心阻抗信号采集电路以及心电信号采集电路;信号处理包括滤波、心阻抗信号校准、心电信号和心阻抗信号特征点识别。依据所采集的心阻抗与心电信号,以Nyboer胸腔圆柱模型为理论依据,计算心率(heart rate, HR)、每搏量(stroke volume, SV)、心排量(cardiac output, CO)、每搏指数(stroke index, SI)、心排指数(cardiac index, CI)和心脏收缩指数(cardiac contractility index, ICON)等血流动力学参数。经测试,该系统的硬件关键技术指标优于相关医疗器械标准的要求。该系统采集了40名志愿者的心阻抗及心电信号数据,将所计算的HR、SV、CO这3个血流动力学重要指标与德国OSYPKA Medical的ICON Core无创心排血量监测仪进行对比,其皮尔逊(Pearson)相关系数分别达到0.992(P<0.001)、0.948(P<0.001)、0.933(P<0.001),验证了该系统具有较高的准确性与可靠性。

         

        Abstract: Hemodynamic monitoring can reflect cardiac function and blood perfusion and is an indispensable monitoring method in clinical practice. Invasive hemodynamic monitoring methods represented by the thermodilution method are limited in their clinical application scope because they require vascular cannulation. Non-invasive hemodynamic monitoring has attracted extensive attention from medical companies and clinicians at home and abroad in recent years due to its advantages such as safety, non-invasiveness, continuous monitoring, simple operation, and low cost. This paper designs a non-invasive hemodynamic monitoring system based on the impedance cardiography, including hardware, algorithm, software design, and performance parameter evaluation. Among them, the hardware part mainly includes a differential high-frequency constant current source stimulation circuit, impedance cardiogram signal acquisition, and ECG signal acquisition circuit. Signal processing includes wave filtering, impedance cardiogram signal calibration, and ECG signal and impedance cardiogram signal feature point recognition. According to the collected impedance cardiogram and ECG signals, hemodynamic parameters such as heart rate (HR), stroke volume (SV), cardiac output (CO), stroke index (SI), cardiac index (CI), and cardiac contractility index (ICON) are calculated based on the Nyboer thoracic cylinder model. After testing, the key technical indicators of the system hardware are better than that of the relevant medical device standards. The system was used to collect impedance cardiogram and ECG signal data from 40 volunteers. The calculated HR, SV, and CO, three important hemodynamic indicators, were compared with the ICONCore non-invasive cardiac output monitor of OSYPKA Medical in Germany. Their Pearson correlation coefficients were 0.992 (P<0.001), 0.948 (P<0.001), and 0.933 (P<0.001), respectively, verifying that the designed system has high accuracy and reliability.

         

      /

      返回文章
      返回