A multifrequency constant current source suitable for Electrical Impedance Tomography (EIT)

Constant current source is essential in Electrical Impedance Tomography (EIT) for injecting a sinusoidal constant current to the phantom boundary. In medical EIT the multifrequency scanning is desired for studying the wide range of tissue conductivity among different type of subjects. A multifrequency constant current source is developed for medical EIT and the boundary data of a practical phantom is studied. A sinusoidal constant crrent is injected to the phantom boundary at different frequency levels and the boundary potentials are measured. Results show that the developed current source efficiently generate constant current with minimal amount of noise at different frequency levels. Boundary data are successfully generated at four different frequencies and found suitable for image reconstruction study in multifrequecy EIT.