This is a PhD studentship for Oneeba Ahmed in Dr Xinli Du’s lab at Brunel University London. The studentship began in 2024.
Background
Cochlear implants restore hearing to profoundly deaf people by converting sound into electrical signals that the brain can interpret. Cochlear implants contain a long, thin, plastic strip with electrodes embedded into it (called an array). This array is inserted into the inner ear (cochlea) through manual surgery. The electrode array stimulates the hearing nerve with electrical signals in response to sound and these signals are then transmitted along the hearing nerve to the brain.
Manual surgical insertion of cochlear implant arrays into the cochlea can result in trauma to the tissue, often destroying any remaining natural hearing the person has. Minimising trauma during surgery would preserve more of a person’s residual hearing, allow the implant to perform better, and ultimately let the person hear better. In addition, the insertion process, although carried out by highly skilled surgeons, is still subject to human error, as they lack the ability to finely sense where the array is in relation to the delicate structures of the inner ear.
As a result, several research teams are trying to develop robotic surgical procedures, that can take advantage of more sensitive detection methods to both reduce trauma and ensure that electrode arrays are placed in the best possible position within the inner ear to give the best listening outcomes.
Such procedures would help to make outcomes from cochlear implantation surgeries more predictable and ensure that people retain as much of their residual hearing as possible. The higher standard of implantation could ultimately lead to a relaxation of the clinical criteria for eligibility for receiving a cochlear implant, enabling more people to access this technology.
Aims
The aim of this study is to investigate whether combining novel sensing and robotics technologies can improve the positioning of the electrode array and reduce disturbance and damage within the cochlea during the insertion process.
The research group has previously developed a sensing system for use in cochlear implant surgery which measures the electrode’s impedance as it is inserted (the amount of resistance the electrode encounters as it is inserted into the cochlea).
They are also developing robotic technology whose purpose is to insert an electrode array into the cochlea, called a hexapod robotic manipulator. This manipulator can move in six degrees of freedom – that is, it can move up and down, left to right, backwards and forwards, and can also twist in any of those directions.
The student will work to integrate the sensing system with the robotic device. Once they have achieved this, they will test the combined system on 3D-printed models of the cochlea (biologically realistic models that react and resist force like the cochlea does) to measure how effective the system is at inserting electrode arrays into the cochlea, and to verify and improve its performance.
Benefit
The results from this project will demonstrate whether this new combined sensing and robotic system can improve electrode array placement within the cochlea, reducing the potential for damage to the cochlea. This information will be used to improve cochlear implant surgical techniques and thus also improve cochlear implant performance for the listener.