Hearing loss is the third most common health problem in the U.S after heart disease and arthritis. It is estimated that about 48 million Americans have some form of hearing loss, often caused by illness, genetics, or other ear-damaging elements that come with a modern lifestyle (e.g. sporting events, airplanes, concerts, and working with heavy machinery). FDA recently granted a de novo request for the BONEBRIDGE device, manufactured by Austrian company, Med-El. BONEBRIDGE is an active bone conduction implant system, and is designed for individuals 12 years and older who have conductive hearing loss, mixed hearing loss, or single-sided deafness.
To understand who should use this device, we need to understand a little more about the types of hearing loss. Hearing loss can be categorized into 4 categories:
Conductive: Any problem in the outer or middle ear that prevents sound from being conducted properly.
Sensorineural: Hearing loss that results from missing or damaged sensory cells (hair cells) in the cochlea and is usually permanent.
Mixed: As the name suggests— is a combination of conductive and sensorineural hearing loss, indicating damage in both the outer or middle ear, and the inner ear.
Neural: Neural hearing loss results from the lack of or damage to the auditory nerve, which is a bundle of fibers that carries auditory sensory information from the cochlea to the brain.
Traditional cochlear implants help patients who have sensorineural hearing loss as they replace the functional components of the inner ear (read more about cochlear implants on our blog from May 2016)! Alternatively, BONEBRIDGE is indicated for conductive or mixed hearing loss, which means sound cannot take the natural route through the outer and middle ear to the inner ear. This makes it difficult for the hearing loss sufferer to hear soft sounds and can also lead to the muffling of louder sounds.
BONEBRIDGE transmits sound waves via bone conduction directly to the inner ear, where they are processed as natural sound. The device consists of two components: an externally worn audio processor (called SAMBA), and a surgically-inserted bone conduction implant (called the BCI 601) which lies directly beneath the skin. The audio processor is held directly above the implant using magnetic forces.
Now, let’s get into the specifics of how this device works! Initially, the microphones of the audio processor pick up the sound waves. Then, the audio processor converts those sound waves into electrical signals, which are then transmitted through the skin to the implant. The implant, which is fixed in the temporal bone, converts these electrical signals into mechanical vibrations which are transmitted to the skull. The bone then conducts these vibrations to the inner ear. Signal transmission to the inner ear via bone conduction bypasses the outer and the middle ear, solving the complication of sound’s inability to pass through the natural route that comes with conductive and mixed hearing loss. The inner ear then processes these mechanical vibrations in a way that is similar to the way natural hearing is processed, and transmits nerve signals to the auditory nerve in the brain.
The audio processor is equipped with adaptive directional microphones, which adapts to different environments and individual usage. One of the really cool things about the audio processor (not that the device isn’t already super cool) is that it automatically identifies and minimizes noise interference in situations where there is loud background noise, which can become overwhelming to people who aren’t used to those background noises. The audio processor also comes with a remote control that has wireless connectivity capabilities. Using this remote control, the users can select different programs that have various settings depending on the user’s current environment or activity.
FDA classified BONEBRIDGE under product code PFO as a Class II device with special controls. These special controls include:
1. Clinical performance testing
2. Non-clinical performance testing (includes impact testing, mechanical Integrity testing, etc.)
3. Biocompatibility testing
4. Sterility of the patient-contacting components of the device
5. Shelf life of the device
6. Wireless compatibility, electromagnetic compatibility, and electrical safety
7. Software verification, validation, and hazard analysis
We’re so excited to see medical technology like this enter the US market!