Bilal Tasdelen1,2, Mustafa Utkur1,2, Ergin Atalar1,2, and Emine Ulku Saritas1,2
1Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2National Magnetic Resonance Research Center (UMRAM), Ankara, Turkey
1Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2National Magnetic Resonance Research Center (UMRAM), Ankara, Turkey
We propose a vector modulator based active compensation method and a lookup-table-based algorithm for reducing the direct feedthrough interference by more than 40 dB within two seconds. We demonstrate a significant increase in detection sensitivity.
Figure 3: (A) Boxplot of the simulation results showing the performance of the algorithm with and without measurement noise added. There is a high correlation (ρ=0.45) between the final cancellation and the initial feedthrough. (B) Monitoring the feedthrough level over 20 seconds, while heating the coil. Green dashed boxes mark the time intervals where the algorithm was running. The threshold for running the algorithm was -50 dBV. Different initial isolations are set up by adjusting the gradiometer knob.
Figure 1: (A) Diagram of the AWR (bottom) and vector modulator (up). (B) AWR coil (bottom) and the small pickup coil positioned on top. (C) Vector modulator. An Arduino Uno Rev 3 was used to establish the communication between the rheostats and the computer where the experiments were orchestrated. (D) Photo of the overall system.
