Reaserch Of Networking Three-dimensional Electrical Impedance Tomography Imaging System

Electrical impedance tomography (EIT) technique is based on the distribution characteristics or variation of internal field in 2 D/3 D images, which provides a basis for the evaluation of internal object with noninvasive detection. EIT has been widely applied in medical imaging because of high safety, low cost and in-time mornitoring.Most of the electrical impedance imaging systems are taken by FPGA, DSP and PXI bus controller as the control core of the data acquisition system.The data is uploaded to the host computer through the serial port or USB port for processing and imaging.With the wide use of internet and the urgent requirement of networking medical instruments.the EIT data transmission by internet is a necessary tendency.Therefore,the main task of this thesis is to develop a networking 3D EIT system on previous basis.This thesis mainly includes:1. Based on MicroBlaze soft core processor and DM9000A network module, the platform is built with ISE14.1/EDK. In order to debug the program facilitatly,STM32F103ZET is used as the core controller. The DM9000A network module ensures the initialization of the network communication. ARP, ICMP, UDP and other protocols are tested in the test program.A packet capture tool of wireshark software is utilized to monitor the process of communication.2. The UDP communication server software and client software are designed through UDP interface function in LabVIEW2013. The real-time and reliable data transmission of UDP communication is realized. The HMI of the developped networking 3D electrical impedance imaging system includs network interface configuration, commands setting.working pattern selection, data acquisition, curve displaying. HMI realizes the EIT data acquisition, data processing and the display of the boundary voltage curves.3. In this work, the relationship between respiration and EIT data is studied preliminarily. The EIT data of normal respiration and deep respiration are collected by Agilent 4294A instrument from volunteers. The results showed that in the process of pulmonary ventilation, the impedance value within the thorax changes cyclically at normal breathing and slow deep breathing. And the amount of gas change during deep breathing is greater than that of normal respiration, which is correspondance with the physiological information of lungs capacity greater than the tidal volume. After reconstruction by conjugate algorithm, the images give out direct visionable evaluation to the ventilation function.