一种基于多频电阻抗断层成像系统的校准方法研究

目的：研究一种简便、有效的多频电阻抗断层成像数据采集系统的幅频和相频校准方法，以提高成像数据的质量．方法：基于系统的正交数字解调方法的特点，提出相频和幅频校正方法；通过电阻网络模型和单通道测量实验给出校正因子的获取方法：开展物理模型实验，对比校准前后的数据质量以及成像结果。结果：物理模型实验表明，校准后的数据质量明显得到改善，成像结果能够清晰地反映成像目标。结论：该校准方法是一种简便、有效的多频电阻抗断层成像系统的幅频和相频校准方法，为未来将多频电阻抗成像技术应用于临床奠定了良好的基础。

Calibration Method Based on Multi-frequency Electrical Impedance Tomography System

Objective To develop a simple and effective method that calibrates amplitude frequency and phase frequency of multi-frequency EIT data acquisition system, so as the quality of imaging data can be improved to lay a solid foundation for multi-frequency EIT. Methods A calib＇ration method of amplitude frequency and phase frequency was proposed based on the system characterization of orthogonal digital demodulation. Subsequently the method to acquire the calibration factor was given by the experiments of resistor network and single-channel measurement. Finally physical phantmn experiments were conducted and data quality as well as image results were contrasted before and after calibration. Results The results of physical phantom experiments showed that after calibration there was a significant improvement of data quality and the imaging target could be clearly reconstructed. Conclusion This method is simple and effective for calibration of amplitude frequency and phase frequency of multi-frequency EIT system.