Boone K G, Holder D S
University College London, UK.
Physiol Meas. 1996 Nov;17(4):229-47. doi: 10.1088/0967-3334/17/4/001.
Electrical impedance tomography (EIT) is a novel medical imaging method, which allows reconstructed tomographic images of the internal impedance of a subject to be made with the use of a ring of electrodes. High precision impedance measurements are needed, because the image reconstruction process is ill-conditioned and small errors in measurement can lead to large errors in the final image. In practice, there are formidable instrumentation problems, due to the interaction of finite current drive output impedance, recording amplifier common mode rejection, and unequal skin-electrode impedances. A number of different EIT systems have been constructed or are under development. These employ differing strategies, such as additional electrodes, multiple electrode current injection, or recording at multiple frequencies, to improve image accuracy. This paper reviews the nature of the instrumentation problems and the designs employed by differing groups in attempting to overcome them.
电阻抗断层成像（EIT）是一种新型的医学成像方法，它能够利用电极环对受试者内部阻抗进行断层图像重建。由于图像重建过程是病态的，测量中的小误差可能会导致最终图像出现大误差，因此需要进行高精度的阻抗测量。在实际应用中，由于有限电流驱动输出阻抗、记录放大器共模抑制以及皮肤-电极阻抗不相等之间的相互作用，存在着巨大的仪器问题。已经构建或正在开发许多不同的EIT系统。这些系统采用了不同的策略，如增加电极、多电极电流注入或多频率记录，以提高图像精度。本文综述了仪器问题的本质以及不同团队为克服这些问题所采用的设计。
