Cortical activation of passive hand movement using Haptic Knob: A preliminary multi-channel fNIRS study

Several functional neuroimaging studies had been performed to explore the sensorimotor function for motor imagery and passive movement, but there is scanty work that investigated the cortical activation pattern for passive movement using functional Near-Infrared Spectroscopy (fNIRS). This study investigated the cortical activation pattern from fNIRS data of 8 healthy subjects performing motor imagery and passive movement tasks using a Haptic Knob robot. Group averaged contrasts were defined as motor imagery versus idle and passive movement versus idle. The cortical activations for motor imagery appeared on the contralateral sensorimotor area, whereas the cortical activations for passive movement appeared on both contralateral and ipsilateral sensorimotor area. This result suggests that the performance of passive movement has a wider cortical activation compared to the performance of motor imagery.

I. Introduction

Sensorimotor functions are often impaired after a stroke. Brain structures and functions related to stroke injury can be reorganized and motor functions can be restored by neural plasticity. Haptic Knob (HK) is a robotic device that enables subjects to do the passive movement (PM) by opening or closing theirs hands [1]. The recent development of robot-assisted rehabilitation helps stroke patients to recover their hand functions; a HK with brain computer interface (BCI) is expected to explore new approaches in motor rehabilitation for stroke patients.