基于ARM的32电极电阻抗成像系统设计

Design of 32 Electrodes Electrical Impedance Tomography System Based on ARM

电阻抗成像是一种新型的医学成像技术,在生物信息检测与成像方面具有广阔的应用前景。针对现有电阻抗成像系统采集速度不高、实时性较低、分辨率不理想的情况,进行了改进设计。采用ARM处理器构建嵌入式电阻抗成像系统,搭建32电极物理模型作为检测对象,利用32通道多路开关实现激励电流和电压采集通道的切换,向模型中注入激励电流信号并通过前置滤波、两级放大等信号处理技术获得成像数据。采用敏感矩阵算法对有无目标时的数据差值进行图像重建。实验结果表明,该系统具有较好的成像效果,分辨率高,能有效地实现对目标区域的检测。

Electrical impedance tomography is a new technique of medical imaging, which has a broad application prospect in biological information detection and imaging. In this paper,improved design is carried out in the case of low acquisition speed,poor real-time per- formance and unsatisfying resolution of the EIT system. In the experiment, an ARM processor is used to construct the embedded EIT sys- tem ,the 32-electrode physical model is acted as a detection object,and the 32-channel multiplexer realizes the switching among electrode excitation and measurement channels. The excitation current signal injected into the model is passed through the pre-filter,two-stage am- plifier and other signal processing technique to get imaging data, from which difference between existence and non-existence of the tes- ting object is obtained. Further,image reconstruction of electrical impedance tomography is achieved through the sensitivity matrix algo- rithm. The experiment shows that the system has a good effect, and high resolution, and could effectively realize the detection of the target area.