EIT的图像重建依赖于所采集到数据的精度。电极及其引线对EIT数据采集有着非常大的影响,主要在于如何获得有效的、适合高精度采样的模拟信号。采用16电极设计了一套将电极、开关阵列、模拟前端、模数转换及数据传送等一体化的面向乳腺EIT检测的高精度实验系统。对电子开关阵列进行了改进设计,采用以ADuC834为核心的、高精度的数据采集、传送及系统控制电路,并采用环形电路板。使用该系统进行了初步成像实验,获得了较好的成像效果。结果表明,采用高精度数据采集系统进行EIT成像是可行的,新系统从测量数据的表现上看有更高的测量精度。模拟电子开关阵列的改进,对降低开关特性对EIT数据采集的影响起到一定的作用。
The image reconstruction in EIT system relies on the precision of the collected data.The electrodes and their leads affect the data collection in EIT greatly.How to obtain effective analog signal fitting high precision sampling is one of the main problems.A data collection system was designed and an integrated prototype of breast EIT was also developed,which was composed of 16 electrodes,a switch array with multiplexers in a parallel structure,an analogue amplifier,a 24-bit A/D converter and data transmission system.The integrated prototype used the real full data collect chip ADuC834,and an annular PCB board,integrating all circuits on it.Some preliminary experiments of EIT image were made and the result was satisfactory.The integrated data collection system was proved to be effective and efficient,having better performance in measurement precision.