Page 341 - Handbook of Biomechatronics

334 Borna Ghannadi et al.

rehabilitation has been successful in laboratory-based studies, it needs more
clinical trials. Currently, available BCIs can improve motor function, if they
are applied in a larger number of therapy sessions (Mrachacz-Kersting et al.,
2016). Further developments of this system depend on our knowledge of
motor recovery and skill learning, involved motor centers, and intervention
mechanisms. Discoveries in these areas will lead to more reliable clinical
BCI-based therapy (Daly and Huggins, 2015).

7.2 FES-Based Strategies for Control and Rehabilitation

With FES, a series of electrical pulses are applied to the skeletal muscles of the
affected limb to compensate for the loss of voluntary neural commands. It is
possible to modulate the amount of force produced in the muscles by con-
trolling either the electrical current or pulse-width of the stimulation (Sharif
Razavian et al., 2018). FES has been shown to be an effective therapy pro-
gram in restoring hand function in severe chronic stroke patients (Kapadia
et al., 2014; Thrasher et al., 2008). Due to the complexity of the FES con-
trol, the combination of robotic and FES therapy paradigms has been pro-
posed (Hu and Tong, 2014; Kapadia et al., 2014). In such setups, the robot is
usually used to resist the motion while “guiding” the patient’s limb, while
FES is the main driver of the affected limb. Therefore, a robotic controller is
needed to allow for such interactive movement.
Combination of FES with an upper extremity stroke rehabilitation robot
is an ongoing research, which is mostly focused on its possibility (Hu and
Tong, 2014; Kapadia et al., 2014). Recently, at the University of Leeds
(United Kingdom), a proof of concept study on the feasibility of this com-
bination has been performed (O’Connor et al., 2015). In this study, “iPAM”
(double-robot manipulandum) was used to assist active reaching of a subject,
and “Odstock Pace” (neuromuscular electrical stimulator) was assisting and
restoring grasp in the subject. In a big picture view, if “Odstock Pace” is
viewed as an exoskeleton, this system can be considered as a semiexoskeleton
(see Fig. 1), which is used for reach-and-grasp arm movement.
The objective of this study was to enable natural prehension (reach-and-
grasp) instead of over-imposed therapy, which is achieved by separate
reaching and grasping exercises. “iPAM” provides arm reaching (shoulder
and elbow motion) from a target to another target; once the hand is close
to the reaching target, “Odstock Pace” is triggered by “iPAM” and it stim-
ulates forearm muscles to open the patient’s hand. The results of this study
proved the possibility of combining FES with an upper extremity rehabil-
itation robot.