Development of an active haptic cane for gait rehabilitation

This research aims to develop a novel gait assistive device with enhanced gait stability and training efficiency for stroke patients. The proposed assistive device for mobility aid is composed of a motored wheel and a cane for providing only a light grip force, which prevent a patient using excessive support force of an upper limb like a conventional cane and motivate the patient to use more actively a paralyzed limb due to the reduced weight support. In addition, the proposed device can provide the user with intuitive and safe interaction during walking by integrating an F/T sensor and a tilt sensor at the cane, and a switch sensor at the hand grip. Also, admittance control has been implemented for a patient, it intuitively changes cane speed by measuring interaction forces at the hand grip. A hemi-paretic stroke patient participated in the walking experiments as a pilot study to verify effectiveness of the proposed system. The results showed that the patient could improve walking speed and muscle activation during experiments with a constant speed mode of the haptic cane. Moreover, in the admittance control mode of the haptic cane, the patient could keep higher preferred walking speed and higher gait stability regardless of magnitude of resistance forces. The proposed gait assistive device with cheap, compact and easy-to-use characteristics can provide efficient gait training modes to chronic stroke patients.