Suggestion of new concept for mobility assistive system based on wheelchair platform with gait assistive function controlled by artificial pneumatic muscle

Purpose A problem related to musculoskeletal function degeneration may be occurred in patients who experience gait disorders if they use wheelchair-based mobility assistive system only with no gait exercise for long periods of time. Therefore, in current study, we aimed to suggest a new concept of a mobility system that integrates a wheelchair platform, used for the implementation of mobility, and a wearable exoskeleton structure, used for the implementation of gait assistance, and to validate its structural stability and gait control confidence. Methods A new system was designed and manufactured and its structural stability and gait control confidence were validated. The basic structure of the system was designed based on the platform of a wheelchair for the implementation of mobility, and incorporated a wearable exoskeleton structure formed with six one-degree-of-freedom (DoF) rotational joints for implementing the function of gait assistance. In the case of the wearable exoskeleton part, 12 pneumatic artificial muscles were attached for the 1-DoF flexion-extension operation of the hip, knee, and ankle joints. Results The results showed that the structural stability of the system was sufficient and the control operation of the system accurately simulated the joint angle change patterns that occur during general normal gait, within an error range of 2.6 ± 10.8%. Conclusions Our new system suggested may potentially be applicable for gait assistive function incorporated with a wheelchair platform for movement. This study may be valuable because it initially suggest a new concept of the wheelchairtype mobility assistive system with gait assistive function.