Electrical impedance imaging system using FPGAs for flexibility and interoperability.

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Medical Imaging

Background:

• Modern Electrical Impedance Tomography (EIT) systems require integrated functionalities for enhanced clinical applicability.
• Field-Programmable Gate Arrays (FPGAs) offer a flexible platform for developing complex EIT systems before committing to Application-Specific Integrated Circuits (ASICs).

Purpose of the Study:

• To describe the FPGA design of the KHU Mark2.5 EIT system.
• To classify and implement essential EIT functions within FPGA architecture.
• To provide a foundation for future digital ASIC designs in EIT.

Main Methods:

• Classified EIT functions into current injection/voltage measurement and data management/control.
• Implemented these functions using two types of FPGAs: impedance measurement module (IMM) FPGA and intra-network controller FPGA.
• Conducted functional and timing simulations for key FPGA operations.

Main Results:

• Successfully implemented multiple EIT functions on FPGAs in the KHU Mark2.5 system.
• Demonstrated the system's capability through phantom and animal imaging experiments.
• Showcased advanced imaging techniques like fast multi-frequency and ECG-gated imaging.

Conclusions:

• Optimizing digital design in parallel EIT systems is crucial for minimizing artifacts and maximizing performance.
• The KHU Mark2.5 EIT system's FPGA design supports numerous clinical functions.
• The described FPGA architecture serves as a basis for developing future EIT digital ASICs with improved performance and human interface.