Eyelid reanimation prototype for facial nerve paralysis

Abstract

Facial nerve paralysis affects thousands of people each year in the USA, and patients lose their ability to control the eyelid in severe cases. Existing passive medical treatments do not provide a functionally or cosmetically satisfaction. Automatic eyelid reanimation combining natural blink detection and electrical stimulation on the paralyzed eyelid has been verified in animal models in previous studies as a potential treatment for facial nerve paralysis. However, development of an implantable device for patients with facial nerve paralysis has not occurred due to the design challenges, including physical pain during stimulation, the latency between the natural blink and the artificial blink, and the patient-to-patient differences. To achieve the final implantable device, a prototype is required at the early stage for further eyelid reanimation study in animal and human trials. In this chapter, we describe an automatic eyelid reanimation prototype that addresses these design challenges. The real-time blink detection and electrical stimulation have been implemented in this prototype in combination with a field-programmable gate array (FPGA) and two custom-built integrated circuits (ICs). Preliminary tests on human and rabbits have conceptually validated the function of blink detection and electrical eyelid stimulation.