Surgical approaches and acute response to small-package implantation of the tympanic membrane

Most current implantable hearing prostheses require an external package to capture and process sound before transmission to the implant. Making all of the implant components completely implantable is desirable because it reduces the problems with power consumption, improves convenience and robustness as well as providing greater cosmesis. The key limiting factors for fully implantable device are battery life and the need for an effective microphone. Apart from the transmission loss of sound through skin, subcutaneous microphones have also suffered from picking up body and (scalp-) hair noise. Additionally, as part of their operation, microphones require a pressure-equalisation hole to cope with variations in atmospheric pressure. This hole carries a severe risk of harbouring infection and needs to be removed from any design.

Graphene, a single-layer thick array of carbon atoms, can withstand enormous deformations without permanent damage. It has already been used to make static pressure sensors. Collaborating with the National Graphene Institute, and supported by the NIHR Manchester Biomedical Research Centre (BRC) the Manchester Centre for Audiology and Deafness (ManCAD) is seeking to develop a graphene-film microphone in a package that would be implanted in the tympanic membrane. This would eventually be incorporated into cochlear implant systems to allow the development of a fully implantable device. We are seeking a trainee ENT surgeon with significant experience of ear surgery in order to further the development of such a microphone.

The successful candidate would have three key roles:

1) Development of the surgical technique for implantation. This will be undertaken in the anatomy dissection laboratory using cadaveric heads.
2) Development of the microphone housing. This will take in to consideration the constraints of the microphone design and the requirements for biostable and efficacious microphone placement
3) In vivo biocompatibility testing of the implanted microphone housing. This will utilise an animal model.

This work will be undertaken as part of an MD.

Training/techniques to be provided:
The successful candidate will undergo appropriate animal husbandry training and will obtain a Home Office animal license. The surgical technique for microphone placement will be developed under the supervision of Professor Simon Lloyd and the successful candidate will be trained in advanced tympanoplasty techniques. The in-vivo work will be carried out under appropriate supervision. Training in animal anaesthesia and surgical techniques will be provided.

Entry Requirements:
The candidates must have their MRCS (or equivalent) and must be a trainee at specialist registrar level . They must have some experience of tympanoplasty surgery. They must be enthusiastic, hardworking and have a questioning mind. They should also have some experience in basic research methodology.