What are the differences in implantable and non-implantable bone anchored systems?
There are basically two types of bone anchored solutions: direct drive and skin drive. There are fundamental differences between these two types of bone conduction technologies. In the skin drive solution the bone conducting vibrator sits on the outside of the skull. Magnets are used to keep the vibrator in place. Vibrations are transmitted from the transducer across the skin to the skull. The significant down side of this solution is the attenuation of sound energy up to 20 dB in the high frequencies during transmission across the skin.
Examples of the skin drive solution include the Sophono and the BAHA Attract. They are also known as passive transcutaneous bone conduction devices. The stimulation pathways and hence the outcomes are similar to that of a Softband. The processors press against the skin.
In the direct drive solution, vibration forces are delivered directly to the cochlea. Two examples of this solution are the Oticon Medical Ponto and the Bone Conduction Implant (BCI). The Ponto is often referred to as percutaneous bone anchored solution. Sound is transmitted directly to the skull from the sound processor via a skin penetrating abutment and an osseointegrated implant in the temporal bone.
The BCI is also known as a transcutaneous active solution. The vibrators that are imbedded very close to the cochlea in the temporal bone. There is less transmission loss and better high-frequency gain compared to skin-drive devices.
The percutaneous Ponto bone anchored hearing system provides the most efficient transfer of vibration to the skull and into the cochlea. It delivers the best audiological outcomes when used in accordance with the correct indications. The surgery is straight forward, quick, and is typically performed under local anesthesia. It is FDA cleared and reimbursable in the United States. For more information about Oticon Ponto, please visit www.oticonmedical.com or the Oticon Medical Expo Page on AudiologyOnline.