Lipeng Wang

Aiming at solving the problems of low compliance and unsatisfactory therapeutic effect in most existing waist rehabilitation robots, this letter presents a compact waist rehabilitation robot (CWRR) for patients with low back pain (LBP). First, the CWRR with a rigid pose adjustment mechanism and a soft curvature adjustment mechanism is designed to adapt to the waist movement and adjust lumbar curvature. Then, the kinematic analysis was conducted using the closed-loop vector method and the phenomenological theory model. Finally, unit mechanism tests and a comprehensive prototype test were carried out to validate the rationality of the theoretical models and the adaptability and compliance of the CWRR. The CWRR adjusted the curvature angle within the range of 10–60 degrees with small errors. Under different pose and curvature conditions, the man-machine contact pressure was lower or slightly higher than the low-pressure regime threshold (10 kPa). Experimental results show that the CWRR possesses potential clinical applications for patients with LBP disease and can provide theoretical and technical reserves for the research and development of curvature-adjustment waist rehabilitation robots.

Conventional lower-limb rehabilitation robots cannot provide in-time rehabilitation training for stroke patients in the acute stage due to their large size and mass as well as their complex wearing process. Aiming to solve the problems, first, a novel hybrid end-traction lower-limb rehabilitation robot (HE-LRR) was designed as the lower-limb rehabilitation requirement of patients in the acute stage, in this paper. The usage of (2-UPS + U)&(R + RPS)&(2-RR) hybrid mechanism and a mirror motion actuator had the advantages of compact structure, large working space and short wearing time to the HE-LRR. Then, the mobility of the HE-LRR was calculated and the motion property was analyzed based on screw theory. Meanwhile, the trajectory planning of the HE-LRR was carried out based on MOTOmed^® motion training. Finally, the motion capture and surface electromyography (sEMG) signal acquisition experiments in the MOTOmed motion training were performed. The foot trajectory experimental effect and the lower-limb muscle groups activation rules were studied ulteriorly. The experimental results showed that the HE-LRR achieved good kinematic accuracy and lower limb muscle groups training effect, illustrating that the HE-LRR possessed good application prospects for the lower-limb rehabilitation of patients in the acute stage. This research could also provide a theoretical basis for improving the standardization and compliance of lower-limb robot rehabilitation training.