Towards Optimal Platform-Based Robot Design for Ankle Rehabilitation: The State of the Art and Future Prospects

Table 2

Examples of ankle rehabilitation robots with optimal design for different applications.

Examples	DOF	Type	Alignment	Posture adjustability	Workspace	Actuation torque	Application fields
Zhang et al. [7]	1	SM-based platform	Yes	Yes	Appropriate	Appropriate	+
OptiFlex Ankle CPM [20]	2	SM-based platform	Yes	Yes	Appropriate	Appropriate	++
Zhang [21]	3	PM-based platform	Yes	Yes	Optimization should be conducted for appropriate robot workspace and actuation torque, and reconfigurable design should be also encouraged.		+++

SM: serial mechanism; PM: parallel mechanism.
Note: represents the characteristics an optimal ankle rehabilitation robot must have; + refers to the fields of intelligent ankle stretching only for dorsiflexion/plantarflexion; ++ refers to the fields of passive training for ankle inversion/eversion and adduction/abduction; +++ refers to the fields of comprehensive ankle training in a three-dimensional space.