Evaluation and Testing

Before the fMRI compatible robot was used in fMRI experiments we performed extensive testing and evaluation. All tests were carried out on the same day using echo planar imaging sequences, which are commonly used in fMRI experiments. The sequence parameters were fixed throughout the experiments. A cylindrical imaging object was placed inside the scanner. The first set of images was acquired without the haptic system inside the examination room. The Phantom was connected to the amplifiers, which were placed outside the room, and a virtual environment task was run. The subject inside the examination room manipulated the robot while another set of images was acquired. The signal-to-noise ratio (SNR) was for both cases calculated according to the NEMA standard. The calculated SNR was 172 for the reference image. The SNR was 172 when the haptic robot operated inside the examination room. With only a slight deterioration of the SNR, we concluded that the operation of the haptic robot has a negligible effect on the quality of the acquired images. Detailed description of the evaluation procedures can be found in the article Robotica.pdf.

To be absolutely sure that there is no interference between the scanner and the robot, a QA test procedure was run for both of the cases above describe: with and without the haptic robot operating inside the examination room. Reports for both cases showed that all parameters are in the specified range. Both reports can be found here: QA-ReportNoRobot.pdf and QA-ReportWithRobot.pdf. All described testing and evaluation was carried out on a Siemens Trio 3 T fMRI scanner at the University Medical Centre Ljubljana, Slovenia. Another independent evaluation was done by BAIC staff on a Siemens Verio 3 T fMRI scanner at the ATR Kyoto, Japan.