Integrated data collection in electrical impedance tomography

Abstract

Electrical impedance tomography (EIT) has 3 outstanding advantages, non-invasive, functional imaging and medical image monitoring. The stray capacitances of the electrode cables and multiplexer array are main contributors to inaccuracy in EIT system. To reduce the stay capacitance, electrode cable must be as short as possible and the multiplexer array must be as efficient as possible. A data collection system has been designed and a integrated prototype of breast EIT has also developed, which is composed of 16 electrodes, a switch array with 4 8-1 multiplexers in a parallel structure, an analogue amplifier, a 24-bit high precision A/D converter and data transmission system. The integrated prototype has no long electrode cables, takes 16 elastic needles as the connective points to the outer object, using the real full data collect chip, and an annular PCB board, integrate all circuits on it. Some preliminary experiments of EIT image have been made, and showed the integrated data collection system works effectively and efficiently. © Springer-Verlag 2007.