Performance Validation of An Upper Limb Exoskeleton Using Joint ROM Signal

Abstract

Exoskeleton systems are emerging for robotic assistive surgery and rehabilitation of neurologically impaired patients. A novel upper extremity (UE) exoskeleton has been developed in our lab, potentially to be used for robotic assistive surgery and stroke rehabilitation in our laboratory. The purpose of this study was to introduce the methodology of voluntary control of the UE exoskeleton by processing the range of motion (ROM) of UE joints. Ipsilateral-to-ipsilateral synchronous (IIS) control and ipsilateral-to-contralateral mirror (ICM) control mechanism were designed for UE exoskeleton movement control. A 3D simulation was performed to validate mechanical designs for kinesiologic motion. The performance of the ROM-controlled UE exoskeleton was then validated among six healthy subjects. The UE exoskeleton performed drawing movements in a 2D panel. The drawings created by the UE exoskeleton were compared to the drawings created by a healthy subject to determine the accuracy of the drawing performance. Reliability statistical analysis (Cronbach test) was performed to determine the inter-rater agreement between subject performance and UE exoskeleton performance. Results showed an excellent agreement between the human drawings and exoskeleton drawings (Cronbach Alpha value = 0.904, p<0.01). This study demonstrated that ROM of UE joints can be processed for voluntary control of a UE exoskeleton. Potentially, UE exoskeletons can be used for robotic assistive orthopaedic surgery and UE rehabilitation trainings.

Wearable upper limb robotics for pervasive health: a review

“…Brahmi et al [123] developed an adaptive tracking control strategy that used backstepping approach coupled with time-delay estimation to estimate unknown dynamics and compensate for external bounded disturbances. Alshahrani et al [124] presented a four-DOF upper extremity exoskeleton utilizing ipsilateral-to-ipsilateral synchronous and ipsilateral-to-contralateral mirror control mechanism for volitional control of the upper limb exoskeleton. Table 2 summarizes the control methods based on non-human biological signals.…”

Study of exoskeletons for upper limb rehabilitation

“…For use in robotic assisted surgery and stroke rehabilitation an upper extremity exoskeleton has been developed [52]. The purpose of this study was to introduce the methodology of voluntary control of the upper extremity exoskeleton by processing the ROM of upper extremity joints 2.15.…”