# Current State of Robotics in Hand Rehabilitation after Stroke: A Systematic Review
###### Abstract  
Among the methods of hand function rehabilitation after stroke, robot-assisted rehabilitation is widely used, and the use of hand rehabilitation robots can provide functional training of the hand or assist the paralyzed hand with activities of daily living. However, patients with hand disorders consistently report that the needs of some users are not being met. The purpose of this review is to understand the reasons why these user needs are not being adequately addressed, to explore research on hand rehabilitation robots, to review their current state of research in recent years, and to summarize future trends in the hope that it will be useful to researchers in this research area. This review summarizes the techniques in this paper in a systematic way. We first provide a comprehensive review of research institutions, commercial products, and literature. Thus, the state of the art and deficiencies of functional hand rehabilitation robots are sought and guide the development of subsequent hand rehabilitation robots. This review focuses specifically on the actuation and control of hand functional rehabilitation robots, as user needs are primarily focused on actuation and control strategies. We also review hand detection technologies and compare them with patient needs. The results show that the trends in recent years are more inclined to pursue new lightweight materials to improve hand adaptability, investigating intelligent control methods for human-robot interaction in hand functional rehabilitation robots to improve control robustness and accuracy, and VR virtual task positioning to improve the effectiveness of active rehabilitation training. e 2  
According to incomplete statistics, nearly 80% of stroke patients develop hand dysfunction, one of the most common symptoms of stroke [5; 6]. Hand function accounts for about 90% of upper limb function and plays an indispensable role in life. Hand dysfunction seriously affects the quality of daily life of patients and their families, and also has a negative impact on patients' psychology, so hand function rehabilitation has become one of the main tasks of stroke rehabilitation. Fortunately, the human motor system is able to restore the function of the injury through intensive and repetitive rehabilitation exercises [7; 8]. In order for stroke patients to better return to society and family, systematic rehabilitation training is particularly important and will directly determine the possible degree of patient recovery. The hand dysfunction left by stroke seriously affects patients' ability to perform daily life activities and social abilities. Since hand function requires the participation of finger fine motor function and sensory function, and also requires the active participation of patients, its recovery is very slow and the rehabilitation efficacy is not significant [9]. In addition to the use of medications, appropriate rehabilitation exercises will have a greater impact on the rehabilitation of a patient's hand function. The central nervous system is plastic, so repetitive rehabilitation will help the patient's limbs to establish new connections with the central nervous system, thus effectively treating stroke disease. In the treatment of stroke disease, effective rehabilitation is the key to treatment. Currently, rehabilitation exercises are used to help repair and rebuild tissues and nerves through repetitive rehabilitation. In addition to traditional rehabilitation methods, there is a need for a more rational and scientific approach to meet the rehabilitation needs of patients, which is why rehabilitation assisted robots have been developed [10; 11; 12]. The role of rehabilitation robots is to help patients perform effective rehabilitation exercises for damaged limb parts, thus promoting rapid recovery of damaged parts. Due to the drawbacks of traditional rehabilitation training methods, a variety of rehabilitation robots have been developed at home and abroad to assist patients to complete repetitive training through rehabilitation robots [13; 14].