New measurement and treatment technologies for hand function rehabilitation

Abstract

Hands with normal function play an extremely important role in the daily life. However, there are shortcomings in the current studies of hand motion. The devices for hand motion detection needs to be improved for a better performance. Besides, the investigation of hand motion patterns of normal people and patients is inadequate. On the other hand, with the development of soft robotics, it has been widely used in clinical rehabilitation since it has safety advantages over the traditional rigid robots. However, there are imperfections existing in current soft robotic gloves. In addition, the current methods for assessing hand function is relatively cumbersome, which has a requirement for hand motor ability. Therefore, this study focused on measurement and treatment technologies for hand rehabilitation, and aimed to provide the solutions to some existing problems. Specifically, four sub-studies were conducted, including: (1) A sensor array for finger joint motion measurement was developed. The application of new sensing material and the design of elastic silicone membrane made the device comply with the human hand anatomy. The simplicity of fabrication is also an obvious advantage of the device. Experiment results have shown that the device performed well in terms of measurement characteristics and mechanical properties. (2) The normal hand motion pattern in rapid grip and release was studied, including the dynamic range of motion, peak velocity, joint sequence and digit sequence in different motion phases. Moreover, the regularities of hand motions were summarized to form hand movement pattern. The comprehensive hand motion pattern allowed us to have a deeper understanding of normal hand function. (3) Quantitative analysis of the performance of the patients with cervical spondylotic myelopathy in the rapid grip and release test was performed. Unlike the conventional studies, the mobility of finger joints and wrist were analyzed, in addition to the number of cycle of motion. Quantitative analysis of more features helped us know more about the impairment of hand function. (4) A new soft robotic glove for hand function rehabilitation and evaluation was developed. It is made of the pneumatic muscles and adopts the modular design. The results demonstrated that the glove has a good performance in terms of joint mobility, bending torque and motor coordination. Besides, the device modularization enhances the practicality of robot, thus it is helpful for the patient’s hand rehabilitation training. In addition, a new method for assessing rehabilitation effects was proposed, which was based on the measurement of gas pressure in the actuators. The condition of hand can be monitored by using the gas pressure of the actuator at the beginning of finger flexion. Both the model test and the clinical trial verified the availability of this evaluation method. Moreover, the effectiveness of the soft robotic glove was proven by the clinical rehabilitation training. To sum up, this study investigated and explores the field integrating soft robotics with hand function analysis, and made some achievements which would be helpful to assist the patients better.