The History of MED-EL Electrode Arrays

One of the main parts of the implant in a cochlear implant system is the electrode array. Electrodes send electrical pulses to the nerve cells within the cochlea, enabling cochlear implant recipients to perceive sound. But not all electrode arrays are created equal. To learn more about the design features that are important for optimal hearing, let’s take a journey through the history of MED-EL electrodes.

Why Cochlear Implant Electrodes Matter

As we showed in our photographic tour of the cochlea, a normal cochlea is lined with thousands of nerve structures. Keeping these cells intact is one of the best ways to ensure hearing performance, both today and in the future.

From the very beginning, MED-EL has pioneered the design and creation of electrode arrays made specifically to preserve these nerve structures. Here are some highlights from MED-EL’s history of electrode development, starting with one of the very first MED-EL electrode arrays introduced in 1989.

1989: Signature Features

When MED-EL was founded in 1989, the first of our electrode arrays incorporated two signature electrode features: wave-shaped wires and a flexible design. These features make for an electrode array that can maximize structure preservation in the cochlea during surgery.

The components of an electrode array from bottom to top: an electrode wire, an electrode wire after the wave shaping, an electrode contact in the middle of an electrode wire, and a contact on the very tip of an electrode wire.

The wave-shaped wires increase the flexibility of the electrode array, and the flexible design means the electrode array can naturally fit the shape of each individual cochlea.

1994: Complete Cochlear Coverage

In 1994, the first 31.5 mm electrode array was introduced by MED-EL. This is special because 31.5mm is the length of the average cochlea. This means it can stimulate the whole length of the cochlea, including the nerve cells responsible for the lowest frequencies of sound.

1996: 12-Channel Electrodes

Today, all MED-EL electrode arrays use 12 electrode contacts to stimulate the cochlea. The very first array with 12 electrode contacts, the STANDARD, was introduced in 1996.

Why 12? Often, people believe that having more electrodes makes for better performance. However, with 12, each contact stimulates only a very specific area of the cochlea and does not interfere with other electrodes. If electrodes are too close together, they may stimulate the same part of the cochlea, causing interference. Also, the space between each electrode—for example, 2.4mm in the STANDARD electrode—makes the electrode array more flexible.

2004: FLEX-Tip Design

A new era of structure preservation started in 2004 when we introduced the FLEX-Tip design for our electrode arrays.

The secret to the FLEX-Tip is that the first five channels in the tip of the electrode array have only one electrode contact. This makes this part of the electrode array even smaller and more flexible so it can fit into the narrower tip of the cochlea.

2011: Expanding Range

In 2011, we expanded our electrode range by introducing the FLEX28.

2013: Electrodes for All

Because we want our cochlear implants to work for everyone, we introduced the FORM series of electrodes. These are designed especially for people whose cochlea is an unusual shape so they can still benefit from the closest to natural hearing that our electrodes provide.

2018: Even More Options

By adding the FLEX26 to the range of arrays available, our cochlear implants can fit even more unique cochleae.

2023: An Electrode Array for Even the Largest Cochleae

The FLEX34 electrode array became available in 2023, enabling complete cochlear coverage for even the largest cochleae with our flexible, soft electrodes.

Individualized Solutions

With our broad portfolio of electrode arrays, our CI users can have  individualized cochlear implants. One size doesn’t fit all, so MED-EL cochlear implants are as unique as our users’ cochleae. And with a pitch-perfect fitting, an electrode array can be fine-tuned to match each unique cochlea even more exactly.

The software that allows for this individualized approach is called  OTOPLAN. This surgical planning tool uses incredibly detailed 3D visualization to help surgeons choose the ideal electrode array based on individual anatomy. With this personalized approach to electrodes, our recipients can get the best coverage for their cochlea and enjoy closest to natural hearing.

Want to learn more about the important role that electrodes play in MED-EL cochlear implants? Then discover how they help us mimic natural hearing so you can enjoy closest to natural hearing.