实时电阻抗成像系统及实验研究

A Real-time Electrical Impedance Tomography System and Experimental Study

介绍了一个32电极实时电阻抗成像系统,描述了该系统的硬件电路设计及图像重建算法,并在盛有盐水的水槽上进行了实时电阻抗成像实验,实验结果表明该系统能够对目标(及多个目标)准确定位,重建图像灰度值的大小可以反映成像区域电导率的相对大小,可以区分成像目标的个数,成像速度可以达到3帧/秒,而且重建图像具有一定的分辨率,能够实时的反映成像区域内部电导率分布的改变。该成像系统非常适合于医学临床应用,如对脑血肿、脑水肿患者的实时图像监护,及时反映患者颅内出血的变化情况,以帮助医生做出正确的诊断,这在医学临床上有着重要的意义。

The hardware design and reconstruction algorithm of a real-time electrical impedance tomography （EIT） system with 32 electrodes are described. Experiments on a saline-filled tank,which dimensions were similar to a human head,with some small targets were designed to obtain images in real-time EIT. The results of experiments show that the EIT system can locate precisely the object＇s （or several objects＇） position in the field. The changes of electrical conductivity distribution in the saline-filled tank can be precisely reflected from the reconstructed image. The EIT system can produce images of. the electrical conductivity distribution at a rate of 3 frames per second. The results of experiments prove that the EIT system based on the equi-potential back-projection algorithm is very suitable for applying in the field of imaging monitoring for a patient with brain hematoma and brain edema. This is very significant to clinical medicine.