Design and Characterization of an Open-Source, High-Efficiency, Easily-Reconfigurable Switch-mode Current Driver for Magnetic Resonance Imaging Applications

Abstract

B₀ shimming and local B₀ field control (will be collectively referred to as “local field control") is a process employed by current and proposed Magnetic Resonance Imaging (MRI) techniques to yield faster and more detailed scans with greater diagnostic utility. Additional scanner hardware, specifically local field control coils and power electronic circuits to drive current into these coils (referred to as “current drivers") are required for these techniques. While current driver designs exist today, they typically trade off efficiency and imaging noise. This work demonstrated a proof-of-concept switch-mode current driver with heatsink-free 10ADC drive capability, <25µsec step response rise-times with multiple loads, acceptable disturbance rejection, all while maintaining comparable imaging quality to that of a linear driver. Design and source files for the driver are released under open source licenses. Further performance areas of improvement have been identified, and work will continue to develop this proof-of-concept device into one with greater research and clinical utility.