Integrated Sit-to-Stand and Stand-to-Sit Training System Providing Biofeedback Information and Physical Assistance to Hemiplegic Patients

Abstract

This paper proposes a novel sit-to-stand and stand-to-sit (STS) training system for hemiplegic patients with clonus. Most hemiplegic patients depend on the unaffected leg and perform plantar flexion involuntarily during STS movements. The developed system integrates a visual biofeedback method with a movement assistance mechanism. The system provides users' ground reaction force (GRF) through a monitor and supports STS movements by moving the seat. We also proposed STS training with physical inhibition by using the developed orthosis to manage clonus. We performed an experiment on a hemiplegic patient who experienced clonus in the affected leg to verify that the user was able to increase the GRF of the heel part (GRFh) of the affected leg while performing STS movements using the system and that the system employing the orthosis reduced clonus. The results showed that GRFh in the intervention test that employed the proposed system was greater than that in the baseline test without the system. We also verified that a significant difference existed between the baseline and intervention test results (p<0.05). In addition, when the orthosis was used, the participant was able to prevent muscle cramps resulting from the clonus by avoiding the contraction of the affected leg muscles. The results indicated that STS training using the system helped the user to increase GRFh and reduce the clonus. In addition, from the viewpoint of motor learning, we deduced that an integrated assistive system with informatics-based biofeedback and physical human-machine interaction would be effective in reconstructing the feedback loop in users' central nervous system.

Keywords

• hemiplegic patients
• sit-to-stand and stand-to-sit movements
• motor learning
• human-machine interaction
• biomedical engineering