Validation of the Novel Body Weight Support System Using Pneumatic Artificial Muscle: A Case Study

Abstract

Locomotion gait training system plays a significant role in therapy for the patients who are in recovering from hemiplegia, paraplegia, spinal cord injury or after stroke. Modern gait training systems commonly use a Body Weight Support (BWS) system which is to enable the spinal cord injury or stroke patients bearing their weight during the walking practice. The conventional rope-pulley mechanism in conventional BWS systems could cause the “pendulum effect” during gait training and make subject be uncomfortable. Furthermore, using only one rope-pulley mechanism the conventional BWS system could not flexibly modulate the supported force, for example, the hemiplegic patient. This research is aimed to develop a novel BWS system which will be used to support the spinal cord injury patient during gait training. The novel BWS system will be applied Pneumatic Artificial Muscles (PAM) for generating the support force. The mechanical structure of the new BWS system is totally different from the conventional body weight support system. Therefore, the new BWS system will have several advantages, such as simplicity, low cost and flexibly adjusting the unloading force. The purpose is to develop a very simple BWS system for gait training, however, its capabilities generating active unloading forces. An experiment with a perturbation was conducted using the new BWS system and a representative conventional BWS system (Counter Weight system) to verify the performance of the new BWS system and to investigate the gait variance of the subject under both two BWS system. The results showed that the new BWS system presented a better performance in comparison with the Counter Weight system.