A Review of Research on Upper Extremity Rehabilitation Robots

Background:: Most of the patients with limb paralysis caused by stroke and traumatic brain injury are unable to take care of themselves, which not only causes great physical and psychological stress to the patients but also poses a heavy burden on their families and society. The global population is entering the aging phase. The number and proportion of older people is increasing in almost every country in the world. Population aging has the potential to become one of the most important social trends of the 21st century, and almost all areas of society are affected by it, including labor and financial markets, demand for goods and services, such as housing, transportation, and social security, family structures, and intergenerational relationships. Rehabilitation robotics is a research field that has emerged from this demand. Objective:: Through the analysis of the current situation and development of upper limb rehabilitation robots, several types of upper limb rehabilitation robots with the most widely used structures today are extracted from the representative results, and each robot is analyzed and elaborated in detail. It provides a reference for readers to choose the appropriate upper limb rehabilitation robots. Methods:: We have classified the upper limb rehabilitation robots through several patents, briefly explained and analyzed the robots grouped, summarized the advantages and disadvantages of various robots, and provided an outlook on future development trends. Results:: Through the research and analysis of the degree of freedom and control system of the upper limb rehabilitation robot, it can be seen that certain upper limb rehabilitation robots have large structures and complex systems, and their application scope is limited; most domestic rehabilitation robots have fewer degrees of freedom and can only provide rehabilitation training for single joints or a few degrees of freedom, especially for the shoulder, which has a small spatial range, too low range of motion and amplitude, and a single mode of motion, and cannot complete a wide range of motion for certain joints, as well as a compound motion for multiple joints, thus failing to provide adequate stimulation of the central nerve. Conclusion:: The analysis shows that the existing upper limb rehabilitation robots are poorly adaptable and not well-suited for situations, such as for different patients and different recovery periods of the same patient. The upper limb rehabilitation robot solution needs to be more appropriately designed to meet all requirements in the rehabilitation movement of patients.