Otologics Carina:

The Otologics Carina is a totally implantable middle ear device, with the microphone, receiver and transducer all implanted under the skin. The transducer works on the electromagnetic principle.

The microphone is positioned under the skin over the mastoid, the transducer is attached to bone, and the actuator is adjusted so it touches the incus, although it can be placed to touch the stapes or footplate.

As the device is attached to skull bones, it is not indicated for children with growing skulls.

The Carina is indicated for mild to severe sensorineural losses as shown, or for mixed losses where bone conduction thresholds are within the shaded range. Speech discrimination scores should also be >40% at 80dB SPL.

It is indicated for patients who cannot wear hearing aids, who suffer with allergic reactions to hearing aids, recurrent outer ear infections, have atresia of the external ear canal, or where surgical reconstruction has failed.

Contraindications include active chronic middle ear disease, a fluctuating hearing loss or profound sensorineural hearing loss.

Outcomes:  The functional gain from a Carina varies from 18dB to 30dB at different frequencies. Studies confirm improvement in speech perception with the device.

Advantages include:
The aesthetic appearance- nothing to see from outside!
No external components, so not affected by water, dust etc.
Patients can swim with it.
It can be left on 24 hours a day.
There is no damage to residual hearing.

Disadvantages include:
Skin noise and loss of clarity with a subcutaneous microphone- other manufacturers prefer an external microphone.
The battery has to be charged up for an hour a day.
The battery will need to be surgically removed and replaced after 10-15 years.
The cost- the device alone costs approximately £12,000, and there will be additional costs for surgery and maintenance.