MED-EL Cochlear Implant Electrode Arrays
There is a growing shift towards personalized treatment in healthcare—and cochlear implants are no exception. Since cochleae naturally vary in size and shape, MED-EL has designed cochlear implant electrodes to be tailored to match each ear’s size and anatomy.
Think of your most comfortable pair of shoes. They are pleasant to wear because they are the right size to fit your feet and have soft insoles that adapt to their shape. Now imagine soft, flexible electrodes that can gently adapt to the shape of your cochlea and can be individualized to fit the size of your ear. That’s how we designed our FLEX electrodes.
The anatomical structures important for cochlear stimulation, such as Rosenthal’s canal and the spiral ganglion, are known to extend deeper than one and a half turns—even up to two full turns—inside normally developed cochleae.[ft][ft][ft][ft][ft]
Only an electrode that’s long enough to span the anatomical structures important for stimulation can make full use of each cochlea’s potential and enable recipients to fully benefit from cochlear implant technology. While ensuring future cochlear health and acting as a crucial bridge between technology and nature, MED-EL’s FLEX electrodes connect hundreds of thousands of people to their loved ones with the closest to natural hearing every day.
- Proven Hearing Preservation
Our flexible electrode arrays help preserve delicate cochlear structures, enabling atraumatic scala tympani insertion and proven hearing preservation. [ft][ft][ft][ft][ft][ft][ft][ft]
- An Electrode to Fit Each Ear
With our comprehensive electrode portfolio, you can easily choose the ideal array to match each cochlea’s length to reach beyond one and a half turns.[ft][ft]
- Complete Cochlear Coverage
Only MED-EL offers electrode arrays long enough to cover beyond one and a half turns and provide the benefits that come with stimulating the apical region.[ft][ft][ft][ft][ft][ft][ft][ft][ft][ft]
- Closest to Natural Frequency Match
With FineHearing replicating phase locking in the apical region, only MED-EL provides both tonotopic (place) and temporal (rate) coding of lower frequencies for the highest hearing quality.[ft][ft][ft][ft]
Individualized Cochlear Implants
Our philosophy is straightforward: Adapt the cochlear implant to your patient’s cochlea.
With normal anatomy, human cochlear ducts typically vary in length from 28 to over 36 mm.[ft] So when it comes to cochlear implant electrode arrays, one size cannot fit all. That’s why we designed our FLEX series arrays to provide the optimal length for the full range of cochlear sizes.[ft][ft]
With six FLEX arrays available in sizes from 20–34 mm, you can achieve complete cochlear coverage and full electrode insertion for each patient.* And with OTOPLAN, we provide intuitive otological surgery planning software so you can easily visualize the insertion depth of the electrode array based on each cochlea’s measurements.** [ft]
1
FLEX20
2
FLEX24
3
FLEX26
4
FLEX28
5
FLEXSoft
6
FLEX34
“Using 3D imaging during the pre-operative planning may improve clinicians’ confidence to implant longer electrode arrays, where appropriate, to achieve optimum hearing outcomes.”
Távora-Vieira et al., 2023
“From an anatomical standpoint, optimal reach of the spiral ganglion would seem to be at two turns [680°-720°], thereby covering the entire frequency range.”
Li et al., 2021
Complete Cochlear Coverage
In natural hearing, the nerve fibers of the spiral ganglion are tonotopically organized and extend two full turns in the cochlea. If an electrode does not cover at least one and a half turns (540°) of the cochlea, it cannot stimulate these nerve fibers and cannot provide accurate pitch-place match. [ft]
Electrode arrays from other manufacturers only cover the basal turn of the cochlea (~360-450°), limiting the stimulation range and leaving half of the cochlea unused. Only MED-EL offers soft, flexible electrode arrays up to 34 mm in length to provide up to two full turns (720°) of cochlear coverage, reaching the apical region. [ft][ft][ft][ft][ft][ft][ft][ft][ft]
“The flexible and straight lateral wall electrode type is reported to be gentle to intra-cochlear structures and has the potential to electrically stimulate most of the neuronal elements, which are necessary in bringing full benefit of the CI device to recipients.”
Dhanasingh et al., 2024
Hassepass et al, 2014; Downing 2018; Ketterer et al. 2018; McJunkin et al. 2018; Skarzynski et al. 2018; Weller at al. 2023; Canforotta et al. 2021.
Cochlear Coverage Contributes to Better Speech Perception
A systematic literature review found that nearly two-thirds (65%) of studies concluded that greater electrode insertion depth, or cochlear coverage, is a contributing factor to speech perception. The review included 23 studies, 15 of which found either a significant positive correlation or a positive effect between insertion depth and speech perception.[ft]
“Patients with deeper insertions perform better in speech recognition tasks and also had a larger benefit of CI with respect to their pre-operative state.”
Weller et al., 2023
More Personalized Care With Anatomy-Based Fitting
With anatomy-based fitting, you can easily fine-tune the frequency map to be closer to the natural map of each cochlea and further optimize hearing outcomes. [ft][ft][ft][ft][ft][ft][ft][ft][ft][ft][ft][ft][ft][ft]
With imaging data from OTOPLAN, you can quickly assign center frequencies in MAESTRO based on the anatomical location of each electrode contact.
“Using anatomy-based fitting and OTOPLAN has changed our clinical practice with cochlear implants and has become a differentiator for our practice and for our patients. OTOPLAN has changed the way we approach each CI patient as it no longer is a "one-size-fits-all" method and really allows us to tailor everything from implant selection to post-op fitting and mapping to each individual patient's needs and anatomy. This helps our patients feel more care is being taken to account for their individual differences and needs.”
Dr. Mary Rose Goldstein
Audiologist in the United States
Closest to Natural Hearing
In the cochlea, natural frequency response is intricately ordered on a logarithmic scale across two full turns. This tonotopic place-pitch frequency response throughout the whole cochlea allows frequency mapping along a clear, logical path.[ft]
How do we provide the closest to natural hearing with our electrode arrays? By aligning our electrodes as closely as possible to the natural tonotopic place across the whole cochlea. What does more natural sound quality mean for your patients? More natural music enjoyment, much better hearing in everyday life, and the best possible hearing experience with their cochlear implant. [ft][ft][ft][ft][ft]
“After losing my hearing, it was difficult to listen to music. And now with the cochlear implant, I can hear more overtones and undertones. I appreciate music to the fullest.”
Russell Tyler, MED-EL cochlear implant recipient and oboist
Designed for Structure & Hearing Preservation
A deaf ear is not a dead ear. The cochlea is filled with intricate structures that we want to protect. That’s why, for over 30 years, we’ve worked to create our soft, flexible electrode arrays. Uniquely engineered, FLEX electrode arrays are the most atraumatic electrode arrays available.[ft][ft]
MED-EL’s FLEX electrodes have the lowest reported incidence of tip fold-over, preserve the delicate structures of the inner ear, and gently adapt to the individual cochlea for atraumatic and reliable electrode insertion.[ft][ft]
Soft, Flexible Electrode Arrays
Our electrodes gently adapt to the unique shape of each cochlea while bringing contacts close to neural targets.
Wave-Shaped Wires
Uniquely shaped flexible wires bend more easily, which helps reduce rigidity and insertion forces in comparison to straight-wire designs.[ft]
Optimal Contact Spacing
Our design offers an ideal combination of mechanical flexibility and channel spacing to reduce insertion force and avoid overlapping stimulation channels.[ft][ft]
Round Window Insertion
With no need for an insertion stylet, our arrays are atraumatically inserted through the round window into the scala tympani, avoiding drilling trauma from a cochleostomy.[ft]
FLEX-Tip Technology
FLEX arrays feature a tapered, rounded tip that gently glides along the scala tympani during insertion, avoiding damage to the basilar membrane and delicate structures.[ft][ft]
“With our FLEX electrode design, MED-EL has engineered the only cochlear implants proven to preserve residual hearing in many recipients.”
Ingeborg Hochmair, Founder and CEO of MED-EL
Only MED-EL's FLEX Electrodes Proven to Preserve Residual Hearing With FDA Approval
Preserving the natural function of the cochlea is especially important for patients with residual hearing. If an array deviates into the scala vestibuli, all residual hearing would likely be permanently lost. Stiff straight and pre-curved arrays are both far more likely to cause loss of residual hearing.
Our soft, flexible lateral wall electrode arrays enable a superior hearing preservation rate for combined electric-acoustic stimulation. Long-term postoperative residual hearing is a useful indication that the natural anatomy and physiology of the cochlea has been preserved. This also offers a more intact foundation of neural structures for future therapies.
Only MED-EL’s FLEX electrodes are proven to reduce cochlear trauma and preserve residual hearing in many recipients. In fact, many MED-EL recipients have functional preserved hearing after receiving a cochlear implant with a FLEX electrode array according to anonymized registry results from a variety of surgeons and hospitals.[ft]
“Lateral wall electrode arrays are preferred for hearing preservation.”
Kant et al., 2022
Round Window Insertion
The round window provides direct access to the scala tympani, making it the ideal route for atraumatic insertion. This avoids the potential trauma of drilling a cochleostomy, as well as the risk of scala vestibuli placement.[ft]
With a 0.8–1.3 mm basal diameter, our arrays are designed for atraumatic round window insertion. And with no need for an insertion stiffener or stiff sheath to be inserted in the cochlea, there is minimal disturbance to the delicate structures at the base of the cochlea.
Even the Smallest Cochlea Can Accommodate a FLEX Electrode
Nearing the apex, the cross section of the scala tympani tapers in diameter to approximately 0.7 mm at 720°. This is why it is important to ensure the array can safely fit in the cochlear duct.
Our atraumatic FLEX arrays use a tapered FLEXTip for the apical 5 electrode contacts. With a tip diameter of 0.4 x 0.5 mm or less, the FLEXTip can be safely and reliably placed up to two full turns the scala tympani without harming the basilar membrane. In other words, the FLEXTip is designed to be like tiny toes easily fitting into the narrow end of a shoe.
“This study represents a wide variability in cochlear morphology and suggests that even in the smallest cochlea, the scala tympani can accommodate a 0.4 mm diameter electrode up to 720°. Additionally, all lateral wall array trajectories were within the anatomically accommodating insertion zone.”
Micuda et al., 2024
Reliable Scala Tympani Placement
Stiff electrode arrays are far more likely to penetrate and damage the delicate membranes between the scala tympani and scala vestibuli. In contrast, MED-EL’s soft, flexible straight arrays are proven to consistently enable scala tympani placement. This way, we can safely preserve delicate structures and deliver better hearing performance to your patients.[ft][ft][ft][ft][ft][ft]
“Considering the current electrode designs available and the reported incidence of insertion complications, the use of straight electrodes in [robotic-assisted CI surgery] and conventional CI surgery (and manual insertion) appears to be less traumatic to intracochlear structures compared with pre-shaped electrodes.”
Van de Heyning et al, 2022
Scalar Deviation
The foundation of structure preservation is electrode placement fully in the scala tympani. If an electrode array deviates into the scala vestibuli, then the perilymph and endolymph would likely mix, destroying the endocochlear potential and impairing essential nerve function.[ft][ft][ft][ft]
However, the scala tympani is separated from the scala vestibuli by incredibly delicate structures that measure only a few microns in diameter. Stiff pre-curved arrays are far more likely to penetrate the basilar membrane and cross into the scala vestibuli. This issue is also possible with stiff straight arrays.
“If one aims to minimize clinically relevant intracochlear trauma, lateral wall arrays would be the preferred option for cochlear implantation.”
Jwair et al., 2020
Lowest Reported Incidence of Tip Fold-Over
With pre-curved electrode arrays, the tip of the electrode array can also become lodged and fold over upon itself. This tip fold-over complication can seriously compromise the interface between the electrode contacts and the cochlea, and often limits coverage to less than three-fourths of a single turn in the cochlea.[ft][ft][ft][ft][ft][ft]
With MED-EL arrays, tip fold-over is rare, with MED-EL having the lowest reported rate of tip fold-over.[ft][ft][ft][ft][ft][ft][ft][ft][ft][ft][ft][ft] The rounded FLEXTip of our arrays gently adapts to the anatomy of each individual cochlea, so there is a very minimized risk of the tip becoming lodged or folding over. In fact, the likelihood of tip fold-over with our electrodes is as low as 1 in 20,000.[ft] In comparison, tip fold-over occurred 1 in 36 times with pre-curved electrodes used by a competitor.[ft]
“Current scientific evidence indicates … that the straight lateral wall electrode outperforms the perimodiolar electrode type by preventing electrode tip fold-over and scalar deviation.”
Dhanasingh et al., 2024
Likelihood of Tip Fold-Over
| Cochlear | Advanced Bionics | MED-EL |
|---|---|---|
| 1 in 36 cases | 1 in 91 cases | 1 in 20,000 cases |
Results of a meta analysis from 17 peer-viewed publications (n=3001). MED-EL data includes additional sources. MED-EL, data on file.
MED-EL: A Trusted Partner
For more than 30 years, MED-EL has been a trusted partner and innovation leader in hearing implants. We’re here to work together with you, and we’re committed to providing outstanding service and support for our professional partners.
With the most advanced cochlear implant systems, we offer the best hearing experience for your patients and the best clinical experience for you.
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SYNCHRONY 2
See why individualized electrode arrays, safe access to MRI, and a streamlined central electrode lead for exceptional surgical handling make SYNCHRONY 2 your new favorite cochlear implant.
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OTOPLAN
With intuitive user interface and powerful 3D visualization, OTOPLAN is the ideal surgical planning software for otological procedures.
* The FLEX34 electrode array is not available in all markets. Please contact your local MED-EL representative for more information.
** OTOPLAN software is a product of CASCINATION AG.
Technical Data
Electrode Arrays
FLEX Series
The softest and most flexible electrode arrays, designed for Structure Preservation and Complete Cochlear Coverage. Featuring 19 active and physical platinum electrode contacts and FLEX-tip technology for atraumatic insertion.
FLEX34
- 28.6 mm stimulation range
- Diameter at basal end: 1.3 mm
- Dimensions at apical end: 0.5 x 0.4 mm
FLEXSOFT
- 26.4 mm stimulation range
- Diameter at basal end: 1.3 mm
- Dimensions at apical end: 0.5 x 0.4 mm
FLEX28
- 23.1 mm stimulation range
- Diameter at basal end: 0.8 mm
- Dimensions at apical end: 0.5 x 0.4 mm
FLEX26
- 20.9 mm stimulation range
- Diameter at basal end: 0.8 mm
- Dimensions at apical end: 0.5 x 0.3 mm
FLEX24
- 20.9 mm stimulation range
- Diameter at basal end: 0.8 mm
- Dimensions at apical end: 0.5 x 0.3 mm
FLEX20
- 15.4 mm stimulation range
- Diameter at basal end: 0.8 mm
- Dimensions at apical end: 0.5 x 0.3 mm
FORM Series
Designed specifically for malformed cochleae and for instances where leakage of cerebrospinal fluid (CSF) is expected. Featuring 24 active and physical platinum electrode contacts and SEAL technology designed to aid closing of the cochlear opening.
FORM24
- 18.7 mm stimulation range
- Diameter at basal end: 0.8 mm
- Diameter at apical end: 0.5 mm
FORM19
- 14.3 mm stimulation range
- Diameter at basal end: 0.8 mm
- Diameter at apical end: 0.5 mm
CLASSIC Series
Features 24 active and physical platinum electrode contacts.
STANDARD
- 26.4 mm stimulation range
- Diameter at basal end: 1.3 mm
- Diameter at apical end: 0.5 mm
MEDIUM
- 20.9 mm stimulation range
- Diameter at basal end: 0.8 mm
- Diameter at apical end: 0.5 mm
COMPRESSED
- 12.1 mm stimulation range
- Diameter at basal end: 0.7 mm
- Diameter at apical end: 0.5 mm
