Design and Simulation of Spine Rehabilitation Soft Robotic Actuator

Pneumatic artificial muscle (PAM) as a soft actuator has the characteristics of lightweight, highly flexible and adaptable, and are enabling safer human-robot interaction. Relevant research has proved that it is instrumental for biomedical rehabilitation. In order to study the bending deformation of PAMs, in this paper, fiber-reinforced PAMs were analyzed using finite element software. The results show that different bending deformations of PAMs can be caused by changing the fiber angle. The smaller the fiber angle, the greater the bending deformation. When the fiber angle is 30°, the bending deformation is not obvious, and when it exceeds 30°, the bending direction changes. In response to this phenomenon of bending due to fiber changes, in this manuscript, a modular wearable soft robotic device for spinal rehabilitation assistance is proposed. By referring to the range of human spine motion, the spinal rehabilitation assistance module is simulated, and the spinal rehabilitation assistance module with fiber angle of 24 ° can better meet the range of lateral flexion (15∼20 degrees) movement of human body. For forward flexion motion, because of its wide range of motion (40 ∼ 60 degrees), it is possible to select a fiber angle that is within the range of human motion. In this paper, the PAM with a fiber angle of 27° was selected as the actuator of forward flexion. From the conclusion, firstly, the simulation study of bending deformation and fiber angle of PAMs has certain guidance for the experiment. Secondly, the simulation results of the module also prove the feasibility of being a wearable soft robotic device.