Development of an exciting source for the system of contactless magnetic induction tomography of brain impedance

AIM: To further explore characteristics of th e impedance of biological tissue and design an appropriate exciting source and i nducing coils for the system of contactless magnetic induction tomography of bra in impedance. METHODS: Based on the principle of the high speed circuits designing, we developed a differential signal source, the freque ncy (between 1 MHz and 10 MHz)and amplitude of which can be linearly justified. Then we discovered the characteristics of the system. Furthermore, parameters of coils were measured and computed. Factors affecting its characteristics were also probed. RESULTS: Specifications of the system at 10 MHz include the constancy of frequency(0 5%), loaded with a coil maxim steady output peak peak voltage(12 V), maxim output current(220 mA), RMS amplitude of no ise(6 1 mV) and signal to noise ratio(63 dB). CONCLUSION: The performance of the system can meet the design requirements protective the system from electromagnetic radiation to a great extent. The inducing coils designed for the system can be also used in detecting experiments. These may be of great help for further imaging work.