Post-Paralysis Upper Facial Movement Restoration in Real Time using Soft Actuators

Facial paralysis is a challenging condition, and current treatments rely on invasive transplant surgeries using a two-stage free muscle transfer procedure. The use of artificial muscles is a novel, less invasive approach, allowing faster recovery and more cost-effective treatment. This paper aims at presenting the use of Dielectric Elastomer Actuators (DEAs), a recent type of smart materials, for post-paralysis upper facial reanimation, by introducing an eyebrow raising muscular prosthesis actuated in real time. The prosthesis aims at replacing the frontalis muscle responsible for raising the eyebrows, a vital function for the expression of emotions and non verbal communication. The facial muscles and neural interfaces governing upper facial eyebrow movements are studied in order to implement a realistic and anatomically precise setup. A non-invasive neural interface relying on myoelectric signals is then successfully used to achieve real-time control of the actuator, by synchronizing the actuator with the activity of a healthy muscle.