Actively Controlled Electrode for Soft Surgery – ACCESS

According to the statistic of World Health Organization, 360 million people, has disabling hearing loss. Cochlear implant (CI) surgery can be used for profoundly deafened patient, for whom hearing aids are not satisfactory, and it is regarded as one of the best options for better hearing. During the implant surgery, the most difficult task is to insert the electrode array (EA) into the tympanic ramp of the patient's cochlea. As the forces involved are extremely low, surgeon has no perception on what happens in the spiral-shape cochlea while he/she is doing the insertion. The failed or incomplete insertion will lead to an incomplete coverage of the tonotopy of the cochlear nerve resulting in frequency distortions at implant activation. Moreover, EA can create trauma to the fine structures of the cochlea (basilar membrane, spiral ganglion nerve), leading to inflammatory response, fibrosis and finally to poor post-operative speech performances or to residual hearing loss.
The current commercialized CI EA are generally made of silicone with about 20 platinum electrodes spread along its length. It is about 0.5mm diameter and about 25mm long. The EA are not actively controlled in shape. Despite the attention paid to the EA design, both categories still face to trauma to cochlea structures.
ACCESS aims (i) a simulation of the electrode insertion through the optimal trajectory, minimizing friction forces and avoiding anatomical obstacle, (ii) a simultaneous control of surgical robot position and EA bending (iii) an actively controlled EA by means of EAP actuators and thin film EA (TFEA), (iv) feedback signals from directly TFEA by using the actuator in sensor-mode.