There is no TRR of brain activation induced by robotic hand passive movement: A functional NIRS study
The basic paradigm of rehabilitation is based on the brain plasticity, and for promoting it, test-retest reliability (TRR) of brain activation in which certain area of the brain is repeatedly activated is required. In this study, we investigated whether the robotic passive movement has the TRR of brain activation. Because active training has been shown to have TRR, but there are still arguments over the TRR by passive movement. In order to test TRR, ten repetitive sessions and various intervals (one day, three days, seven days, 23 days, 15 minutes, and six hours) were applied to five subjects, which had the same statistical power as applying two sessions to 50 subjects. In each session, three robot speeds (0.25Hz, 0.5Hz, and 0.75Hz) were applied to provide passive movement using the robot. The fNIRS signal (oxy-Hb) generated in the primary sensorimotor area (SM1) was measured on a total of 29 channels. At this time, we used activation maps and Intraclass correlation coefficient (ICC) values to examine the TRR and the effect of robot speeds and intervals on TRR. As a result, activation maps showed prominent variation regardless of robot speeds and interval, and the ICC value (=0.002) showed no TRR of brain activation for robotic passive movement.