FPGA-based implementation of Prony demodulation in the multi-frequency EIT system

Multi-frequency Electrical Impedance Tomography (EIT) systems that used in clinical and industrial fields require data demodulation of high precision and high speed. In the paper, a new implementation of the Prony demodulation method by using an FPGA was reported to obtain both the amplitude and phase of the impedance to be measured under each frequency in a multi-frequency EIT system. In order to implement the Prony demodulation in the FPGA, the Prony method was simplified and the floating-point arithmetic was transformed into integer arithmetic according to the characteristics of the FPGA. A hardware system was constructed and experiments were carried out to compare the performance of the new demodulation module with the conventional quadrature demodulation method. The results obtained showed that the FPGA-based Prony demodulation is more flexible and time-efficient than the conventional method.