The early phase of extremity rehabilitation training has high potential impact for stroke patients. However, most of the lower limb rehabilitation robots in hospitals are proposed just suitable for patients at the middle or later recovery stage. This article investigates a new sitting/lying multi-joint lower limb rehabilitation robot. It can be used at all recovery stages, including the initial stage. Based on man-machine engineering and the innovative design for mechanism, the leg length of the lower limb rehabilitation robot is automatically adjusted to fit patients with different heights. The lower limb rehabilitation robot is a typical human-machine system, and the limb safety of the patient is the most important principle to be considered in its design. The hip joint rotation ranges are different in people's sitting and lying postures. Different training postures cannot make the training workspace unique. Besides the leg lengths and joint rotation angles varied with different patients, the idea of variable workspace of the lower limb rehabilitation robot is first proposed. Based on the variable workspace, three trajectory planning methods are developed. In order to verify the trajectory planning methods, an experimental study has been conducted. Theoretical and actual curves of the hip rotation, knee rotation, and leg mechanism end point motion trajectories are obtained for three unimpaired subjects. Most importantly, a clinical trial demonstrated the safety and feasibility of the proposed lower limb rehabilitation robot.

A new applicable sitting/lying lower limb rehabilitation robot is proposed to help stroke patients. It can realize the sitting/lying training postures to fit people in all the rehabilitation stages. Based on the modularization design, the movable seat can be separated from and grouped into the lower limb rehabilitation robot, which is convenient for patients to sit down. As the most important part of lower limb rehabilitation robot, the mechanical leg design theory is introduced in detail. According to the physician clinical suggestions, a new trajectory planning method is proposed based on the dual quartic polynomial interpolation method. It could realize the adjustment of each joint maximum velocity during the training on account of patient recovery. The accelerations of the joints at target position equal zero, which will reduce impact loads on the patients damaged leg. Also, the dwell time the joints staying at the target angular positions can be increased. Those advantages make the lower limb rehabilitation robot more suitable for stroke patient passive training. Combined with the virtual reality technique, a specific motion-playback scene is designed to improve the patient enthusiasm in the training. Finally, a preliminary experimental trial has been conducted to demonstrate the design of the prototype, the motion-playback scene, and the trajectory planning method feasible.

Lower-limb function in elderly people gradually degenerates with age, and poor rehabilitation conditions preventing the elderly from receiving scientific rehabilitation training result in the decline of social labor force and the increased economic burden of the elderly. Aiming at the characteristics of the single function and the complex structure of an existing telescopic leg trainer combined with the needs of the application group, a new type of leg-stretching training device with multiple training modes for lower extremity extension and flexion of the elderly is proposed. A new mechanical structure and electrical system is designed. At the same time, the anti-resistance training man–machine model is analyzed, aiming at the isokinetic resistance training mode, and a training controller strategy based on a fuzzy synovial algorithm is proposed. Finally, the feasibility of the designed controller strategy and the proposed leg training device are verified by prototype experiments, which will guide further research.

Wearable rehabilitation robot (WRR) has become an important tool in the clinical application of rehabilitation medicine, and as WRR is usually attached to the patient's body and in close contact with the therapist, the safety of interaction during rehabilitation is an important consideration for device developers. As the WRR is still in its early stages of development, there is still a gap in international safety standards or technical standards for WRR. As more and more research is conducted on WRR and the technology is gradually improved, the corresponding safety test methods and indicators should be gradually improved. In order to gain a comprehensive understanding of the research hotspots and frontier areas in the field of WRR interactive safety performance, this study analyses the annual distribution of literature, distribution of journals, distribution of research power, important literature, research hotspots and frontiers based on bibliometric methods, and constructs a knowledge model of WRR interactive safety performance indicators. It is found that the research hotspots in WRR safety performance research are mainly focused on four areas: clinical reliability testing, safety performance testing equipment development, mechanical structure optimization and control algorithm optimization. Based on the above research, the knowledge model of interactive safety performance indicators is drawn, and the unified standard for interactive safety testing in the field of WRR safety performance is analyzed and summarized to provide reference for the construction of testing methods for the unified standard for WRR safety testing.