Študija izvedljivosti splošnonamenskega sistema za izvajanje električne impedančne tomografije

Electrical Impedance Tomography (EIT) is a non-invasive imaging technique that reconstructs the internal conductivity distribution of an object by injecting alternating currents and measuring boundary voltages. Its versatility makes it suitable for applications ranging from medical diagnostics to industrial monitoring and structural defect monitoring. A critical element of any EIT system is the current injector, which provides stable, load-independent currents across a broad frequency range. This thesis studies the feasibility of implementing a high-frequency current injector intended for EIT applications up to 10 MHz. The Enhanced Howland Current Pump (EHCP) topology is selected due to its balance between performance and simplicity, supported by high-bandwidth operational amplifier and precision resistors. Special emphasis is placed on mitigating parasitic capacitances, ensuring high output impedance, and optimizing PCB layout for stable high-frequency operation. Measurements and simulations demonstrated that while the prototype performs adequately up to 1 MHz, it fails to maintain stable current injection at 10 MHz. Despite inadequate prototype performance, the work provides valuable insights into the challenges of extending EIT current sources into the megahertz domain. The principal obstacles are identified which offers guidelines for future research toward reliable high-frequency EIT systems.