Proposal of Wheeled Gait-Training Walker with Dual-Assist Arms and Preliminary Pelvis-Handling Control

To achieve good rehabilitation in a person, the amount of walking by the person must be increased. Herein, a compact wheeled gait-training walker with dual-assist arms for assisting pelvic motion is proposed. The training walker is constructed by modifying a commercial wheeled walker with armrests. Therefore, it can be used easily by patients to perform their daily activities at rehabilitation sites. The hardware system and controller of the proposed assisting arms are designed based on gait-assist motions conducted by a physical therapist. The dual arms can achieve a pelvis-assisting motion with five degrees of freedom. A trajectory-following control with virtual compliance is implemented for the arms. Gait-assisting experiments are conducted, in which the dual arms allow a pelvic-like plate to follow the trajectory of a reference pose while reducing the upper body’s weight resting on the armrests. A 20 N force on the armrests, which represents the upper-limb load, is reduced while the plate follows the trajectory, and the proposed gait-assisting controller is validated.

Effects of Gait Inducing Assist for Patients with Parkinson’s Disease on Double Support Phase During Gait

Parkinson’s disease (PD) is a common progressive neurodegenerative disease that affects a wide range of motor and non-motor symptoms. Freezing of gait (FOG) is such a motor symptom of PD that frequently results in falling, and almost half of PD patients suffer from FOG. In this study, we investigated the effectiveness of a robotic assistance system called UPS-PD, which was developed to suppress FOG. The double limb support phase (DLS) in a 10-m straight-line walking task, the gait time and step counts were measured in five PD subjects. In addition, the safety of the UPS-PD in a healthy person was investigated using OpenSim, and the DLS parameters in four healthy elderly subjects were evaluated. In the experiment with the PD patients, the DLS parameters of two subjects showed an improvement. Furthermore, the step length of one subject and the step length and walking speed of the other subject were improved. Moreover, there were no problems in terms of instability of gait in both the PD patients. The UPS-PD did not adversely affect the gait of healthy elderly subjects and the walking of a healthy subject model in the simulation. Therefore, the UPS-PD is considered to be a useful device for improving walking in PD patients.