The simulation of current generator design for multi-frequency electrical impedance tomograph.
In the development of new generation EIT systems, the design of a steady current generator with broad bandwidth is an important consideration. In this paper, the current generator is constructed by enhanced Howland circuit with high-speed operational amplifier. The electronic models of current generator built on Orcad PSpice 9.2 software are simulated to observe the output current stability at multi-frequencies. As results, the THS4021 model provides stable output current at the frequency ranging from 10 k to 1 MHz with the load for 200-2 kOmega. Furthermore, it also offers higher output impedance that equal to 2.1 MOmega at 1 MHz. The results of simulations provide useful approaches of current generator design for EIT system.
Chen
Cheng-Yu
CY
Inst. of Biomed. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan, ROC.
Lu
Yi-Yu
YY
Huang
Wen-Lung
WL
Cheng
Kuo-Shang
KS
D003198:Computer Simulation; D003201:Computers; D004553:Electric Conductivity; D017097:Electric Impedance; D011211:Electric Power Supplies; D004566:Electrodes; D004582:Electronics, Medical; D004867:Equipment Design; D006801:Humans; D019047:Phantoms, Imaging; D012815:Signal Processing, Computer-Assisted; D012984:Software; D014054:Tomography / Q000295:instrumentation* / Q000379:methods