Implantable Bionics Laboratory
Current therapeutic practice for facial nerve paralysis (FNP) involves the fitting of a gold weight on the affected eyelid to force it to close and hydrate the cornea with tears. In most cases remaining muscle function allows for the opening but not the closure of the eye. Moreover, eye closure is not synchronised with the contralateral eye, and is often incomplete.
BLINC includes research and development of an implantable actuator, a surgically-implanted ‘sling’, externally-supplied power and triggering system, and a network of smart sensors to synchronise the eye closure with the contralateral, healthy eye.
Prototype devices have established proof of principle. The next steps include robust testing in vitro and in vivo to demonstrate appropriate device longevity, safety and efficacy before proceeding to pre-clinical and clinical trials.
Facts on the BLINC project
- The most common cause of FNP is Bell’s Palsy. Other causes include neoplastic and trauma-related facial nerve injuries;
- The prosthesis is designed to match the space occupied by the fat and temporalis muscle in the temporal fossa;
- A sling that is formed using harvested tendon material, surgically placed within the upper eyelid. By displacing the tendon by approximately 6 mm, full and natural eyelid closure is achieved;
- Preliminary tests have shown that approximately 650 mN force is required in order to create lid closure using the sling approach;
- For cosmetic reasons, the BLINC device should coordinate lid closure with the contralateral eye. Accordingly, a reliable means of sensing is necessary to detect when the contralateral eye is closing;
- An inductively-coupled ‘link’ transmits power wirelessly to the implanted actuator, obviating the need for implantable batteries or wires passing through the skin;
- The link charges a set of capacitors that are hermetically sealed inside the actuator. When the link is interrupted (turned off), the implanted circuit detects the interruption and discharges the capacitors into the actuator, creating movement of the sling and causing lid closure.
This project encompasses a wide range of studies including:
- Surgical development and study of patient-to-patient biological variation;
- Understanding and analysis of the potential deleterious effects of the sling movement, and means of identifying and managing any risks;
- Assessment of efficacy, longevity and wear;
- Hermetic encapsulation and manufacturing of a self-cleaning, movable actuator interface that is exposed to and surrounded by tissue and body fluids;
- Energising circuit analysis and optimisation;
- Device in vivo performance;
- Sensing systems and synchronisation methods;
- Surgical instrumentation to aid in implantation.