Cochlear implants (CIs) are surgically-implantable biomedical devices that bypass the sensory hair cells and directly excite the remaining fibres of the auditory nerve with electric current. They are capable of restoring a high degree of auditory perception to patients that are severe-to-profoundly deaf. Up to the year of 2012, there were more than 325,000 CI recipients all over the world, and more than 100,000 CI users in Europe, which were about 200 implanted patients per million inhabitants. However, this only accounts for 7% of all adults with hearing impairment that could benefit from a CI in Europe.
CI users usually regain the ability to understand and use spoken language with or without visual aid. However, there remains a wide variation of individual in speech recognition performance after implantation, and the ability of implant users to understand speech diminishes in the presence of background noise. Computational models of the cochlea and sensory neurons have been employed to facilitate the development of CIs via exploring various aspects of electrical stimulation. These models depend on the geometry of the reconstructed cochlea and the exact knowledge of the electrical impedance of different tissues. However, only crude estimation of the impedance of all media is available. Moreover, most existing computational models of the cochlea only adopt an ideal representation of the geometry due to limitations in structural image resolution or in computational expenses.
The aim of CIModelPLUS was to provide engineers an advanced computational model of the cochlea that facilitates the development of next-generation CI. To fulfil the aim of CIModelPLUS, the following objectives were included: 1. development of anatomically-accurate computational model of cochlea; 2. measurement of the electric current distribution; 3. generation of the advanced computational model. All milestones defined for CIModelPLUS have been reached.