High precision Multifrequency Electrical Impedance Tomography System and Preliminary imaging results on saline tank.
To establish a high precision data acquisition system for multi-frequency electrical impedance tomography (EIT), a series of methods were introduced. Those methods include building a driving signal with up to four frequency components to diminish the effect of the dynamic change of tissues resistivity, extracting the impedance information by a digital demodulator that can improve the SNR by 8 times. The system that established can work at a wide range from 1.6kHz to 380kHz. Its CMRR is 74dB at 100kHz. The output impedance of current source is 2M&#937; at that frequency. And measurement precision on a 100ohm resistor is better than -80dB in full bandwidth. Both the quasi-static and the dynamic imaging results based on a saline tank can reflect the resistivity changes inside the phantom clearly. Therefore, the system was competent in multifrequency EIT research work.
Xuetao
Shi
S
Medical Electronic Engineering Department, Fourth Military Medical University, Xi'an, 710033, China.
Fusheng
You
Y
Feng
Fu
F
Ruigang
Liu
L
Xiuzhen
Dong
D