New implant replaces impaired middle ear

FUNCTIONALLY deaf patients can gain normal hearing with a new implant that replaces the middle ear. The unique invention from the Chalmers University of Technology has been approved for a clinical study. The first operation was performed on a patient in December 2012.

With the new hearing implant, developed at Chalmers in collaboration with Sahlgrenska University Hospital in Gothenburg, Sweden, the patient has an operation to insert an implant slightly less than six centimetres long just behind the ear, under the skin and attached to the skull bone itself. The new technique uses the skull bone to transmit sound vibrations to the inner ear, so-called bone conduction.

“You hear 50 percent of your own voice through bone conduction, so you perceive this sound as quite natural,” says Prof Bo H?kansson, of the Department of Signals and Systems, Chalmers.

The new implant, BCI (Bone Conduction Implant), was developed by Professor H?kansson and his team of researchers. Unlike the type of bone-conduction device used today, the new hearing implant does not need to be anchored in the skull bone using a titanium screw through the skin. The patient has no need to fear losing the screw and there is no risk of skin infections arising around the fixing.

The BCI has two parts – one exterior processor and one implant. By a surgical procedure, it is inserted just behind the ear, under the skin, into the bone itself. The coil at the upper end operates using magnetic induction with the outer, visible component, a sound processor that the patient easily can attach to or remove from the head.

The first operation was performed on 5 December 2012 by M?ns Eeg-Olofsson, senior physician at Sahlgrenska University Hospital, and went entirely according to plan.

“Once the implant was in place, we tested its function and everything seems to be working as intended so far. Now, the wound needs to heal for six weeks before we can turn the hearing sound processor on,” says M?ns Eeg-Olofsson, who has been in charge of the medical aspects of the project for the past two years.

The technique has been designed to treat mechanical hearing loss in individuals who have been affected by chronic inflammation of the outer or middle ear, or bone disease, or who have congenital malformations of the outer ear, auditory canal or middle ear. Such people often have major problems with their hearing. NoMarki