心阻抗分析仪的设计
Design of Cardiac Impedance Analyzer

生物电阻抗技术作为一项无创、安全、便捷的检测方法，在生理信息提取和医学辅助诊断领域已取得广泛应用。然而，目前可用于测量心阻抗的设备通常存在工作频率范围狭窄且造价昂贵的限制。为了提高医生在心脏诊断方面的工作效率，我们致力于设计一款基于多核异构技术的心阻抗分析测量系统。本系统采用ZYNQ多核异构芯片，以软硬件协同的方式实现心阻抗激励和数据采集的同步操作，同时也提供了数据可视化和定量分析功能。系统采用了程控变频方法来对心脏进行电流激励，并通过外差定频和正交解调技术，将信号频率稳定解调到低频段，以有效采集心阻抗信号。数据高速传输则通过UDP网络通信方式实现，同时在上位机进行波形的ReBeatICG特征提取，以便计算出血流动力学相关参数，进一步协助医生进行诊断。这款基于多核异构技术的心阻抗分析系统对15名健康受试者的心功能参数进行测量。结果表明：实验图像中能够完整并清晰地检测到人体的ICG信号，ICG信号的特征值提取准确率高达99.56%。15名受试者的各项心脏血流动力学参数均在正常范围内。因此测量系统可以用于人体心功能参数的测量，不仅提高了诊断的效率，还增加了诊断设备的便携性。
Bioelectrical impedance technology is widely used as a safe and noninvasive method for detecting physiological information and providing medically assisted diagnoses. However, devices that cur-rently measure cardiac impedance have limited operating frequency ranges and are often costly. To enhance medical professionals’ efficacy in identifying cardiac-related disorders, we will develop a cardiac impedance analysis and assessment mechanism that will utilize multicore heterogeneous technology. Through a harmonious coordination of hardware and software, the ZYNQ multicore heterogeneous chip facilitates simultaneous cardiac impedance excitation and data acquisition. Ad-ditionally, it offers functions for data visualization and quantitative analysis. The system uses a fre-quency conversion method programmed to excite current in the heart. It stabilizes the demodula-tion of the signal frequency into a low-frequency band by utilizing external difference frequency fixing and quadrature demodulation techniques, ensuring effective acquisition of the cardiac im-pedance signal. High-speed data transmission is achieved through UDP network communication. ReBeatICG waveform feature extraction is executed on the upper computer to calculate hemody-namics-related parameters, which assist physicians in diagnosis. This cardiac impedance analysis system, utilizing multinuclear heterogeneous technology, measured cardiac function parameters of 15 healthy subjects. The results demonstrate that the ICG signal can be accurately extracted with a precision of 99.56% and clearly detected in the image displayed on the experimental measure-ment’s upper computer. Additionally, various cardiac hemodynamic parameters were found to be within the normal range in all 15 subjects. The measurement system can be used to measure vari-ous human cardiac function parameters, thereby enhancing diagnostic efficiency and equipment portability.