Failing Ugly: Advanced Bionics cochlear implant circuit goes haywire


Workhorse HiRes 90K implant circuit recalled as it can “Fail Ugly”

–>Did the surprising lack of burn-in cause this recall?

January 7, 2011; Version 1.2

Please be sure to read the follow-up article Failing Ugly II: More on the Advanced Bionics Recall Although we’re not investigating earlier failures per se, we are interested in how AB handled them.

The Hearing Blog is opening an investigation into the two confirmed, and nine (or more) possible catastrophic failures of the Advanced Bionics HiRes 90K cochlear implant (CI) electronics module in the last several weeks, resulting in extreme overstimulation, causing extreme discomfort to the point of pain and headaches, with the possibility of permanent damage to the cochlea and auditory nerve. In general, when there is a problem with a CI, it will “fail gracefully” by shutting down. However, this particular recall involves the implant “failing hot,” which we call Failing Ugly.

We chose Failing Ugly on purpose: When a CI fails, it should fail gracefully, quietly shutting down until restarted or serviced as needed. Think of driving down the highway and getting a flat tire, where you let off the gas, steer to the shoulder, and coast to a stop: No Big Deal, as Stuff Happens. Now picture this same car with a throttle stuck wide open: This is Failing Ugly, and the end result can be messy, sometimes ending in a wreck. The same is what usually happens when a CI processor or implant fails: It is supposed to fail gracefully, but as we will show in this article this is .NOT. what is happening.

There have been two separate documents circulating about the Advanced Bionics HiRes 90k implant circuit failures: The first was the announcement Tuesday morning (11/23/2010) from Sonova’s Invester Relations department, which was picked up by the Wall Street Journal later that morning in an article titled Sonova Shares Tumble on Hearing Implant Recall. Late Tuesday evening, the Sonova announcement was placed on the Advanced Bionics website. There is now an abridged recall notice here on the FDA website. We also note here that any and all announcements issued by AB over this recall must be approved in advance by the US Food & Drug Administration (FDA).

Beyond that, there was a second document: The official letter sent to AB CI recipients who have devices from the affected batche(s)/lot(s).

UPDATE: The  5 page third PDF document, sent to UK and EU CI centers is in the second article in this series on the AB recall. 

The Hearing Blog received the following copy of the Recall letter at 9:30PM EST on Tuesday night:

This is the email sent out by Advanced Bionics on Tuesday 11/23/2010 at 9:30PM EST (Wednesday 2:30AM UK). This is more serious than in the press release from Sonova’s investor relations department from earlier in the day.

—————**** Recall Notification****—————

Advanced Bionics HiRes 90K Cochlear Implant

Dear Cochlear Implant Recipient or Parent,

Our mission at Advanced Bionics is to improve the lives of the hearing impaired, and the safety and well-being of our recipients is our first priority. Because we are committed to ensuring that our products are as safe as possible, we are voluntarily informing you that we have become aware of an issue with the HiRes 90K cochlear implant. The issue can result in pain, overly loud sounds, and/or sudden shock sensation in the implanted ear while the implant is receiving power.

Thus far, our investigation shows that of the more than 28,000 implanted HiRes 90K devices, only two explanted devices have been confirmed to have this issue. There are 9 other patients with similar symptoms which our investigations have not yet ruled out as related to this issue. For the two confirmed cases, there were no symptoms upon initial activation of device. However, the patients experienced symptoms after 8-10 days of use. Both recipients were re-implanted with HiRes 90K devices and their clinicians report that they are progressing well.

We are conducting an extensive investigation of this issue using an independent scientific research organization. Their current analysis suggests that, if present, the issue will first occur within 90 days of device use. However, the onset of symptoms may be delayed after initial activation, and they may continue to occur intermittently. In the unlikely event that this symptom occurs, continued device use may lead to damage to the inner ear and/or the auditory nerve. If you or your child experience pain related to implant use, remove the external equipment immediately and contact your cochlear implant clinician to schedule an appointment. If the evaluation of your device identifies this problem, device replacement is advised.

It is important to note that it is not unusual for cochlear implant recipients to experience overly loud sounds. Most of these cases can be resolved with standard troubleshooting, such as the replacement of external equipment. The vast majority of these cases are not signs of the issue described above and do not require explant of the device. We will notify you again as more information from our investigation becomes available.

We sincerely regret any concern this notification may cause. Advanced Bionics assures you that we will correct this issue and continue to improve our product reliability. If you have any questions regarding this letter, please contact an Advanced Bionics representative at 877-577-4628 (telephone) Monday – Friday 5:00 a.m. – 7:00 p.m. PST or http://www.advancedbionics.com (live chat) Monday – Friday 5:00 a.m. – 7:00 p.m. PST.

In order to assure the effectiveness of this communication, please complete the enclosed acknowledgment form and return it to us at your earliest convenience by using one of the following options:

E-mail: confirm@advancedbionics.com
Fax: 661-362-7621
Mail: Self-Addressed stamped envelope

Unfortunately, there is a 30 day grace period for the FDA’s MAUDE Adverse Event Report database. Speculation on the Internet is rampant, with this 30 day delay until submissions are made public only stoking fears, of which we will not participate. To date, over 200,000 hearing impaired people have received cochlear implants, from as young as 5 months all the way into their 90’s. Cochlear implant technology is safe and effective for all ages with very few exceptions: This underscores why our independent investigation is important, to ensure the excellent reputation CI’s have achieved over the last two decades is maintained. It is our belief that sunshine is the best disinfectant, so once the cause of these failures is pinpointed and rectified, the Fear, Uncertainty and Doubt (FUD) can be refuted, putting both affected recipients and candidates’ minds at ease.

We need to remind our readers that The Hearing Blog is a privately hosted, independent publication that accepts no advertising, no samples, and no manfacturer or distributor funding. We are modeled on the same decades-long policy Consumer Reports‘ uses, to assure readers the content is unbiased.

We also need to remind our readers that hearing is important: Just look at the 200 thousand people who have undergone general surgery to get it restored, including many of our friends like Kristin Fleig, who was dying to hear again… And (almost) did.


This article is tentatively divided into three subsequent sections:

Engineering Analysis: The “who, when, where, why and how.”

First, what is happening is that there appears to be a component-level failure in the implant circuit, one which overrides the many fail-safe mechanisms built in since this circuit was introduced in 2003. This failure causes an overvoltage — an overcurrent — to be applied to one or more electrode contacts, powerful enough to cause a loud, painful jolt. In addition, there is the distinct possibility this would induce current biasing if (and we stress the word IF) the failure includes a shorted output tantalum electrolytic capacitor, which would cause a(n electro)plating effect, ripping metallic crystals off of the electrode button contacts, destroying it (them) over time… And causing consequent damage in the tight spaces of the cochlea, as such electro-chemical reactions can produce bio-toxic byproducts as well as introduce potentially damaging changes in the local pH. Is this a possibility? Let’s look at the carefully worded recall notice, which was approved by the FDA:

In the unlikely event that this symptom occurs, continued device use may lead to damage to the inner ear and/or the auditory nerve.

This statement would not be present in the recall notice if the failure would not cause damage from bio-toxic byproducts &/or local pH changes. This “failing hot” is also why we use the term “Failing Ugly.
Let’s use an easy-to-understand analogy of one possible failure mode: Picture a Class B (push-pull) audio amplifier with +/- X volt power supply rails coupled to a loudspeaker voice coil through a tantalum electrolytic capacitor. Now, short out one of the two transistors, connecting that supply bus directly to the capacitor: The voice coil is still protected, because the capacitor blocks the DC bias — It acts as a fail-safe, limiting damage. This is also why we qualified the failure above with the word IF. Now, IF we have a second failure where the capacitor shorts out — which is the failure mode of tantalum electrolytic capacitors — now the power supply bus is directly coupled to the loudspeaker voice coil, which will cause the speaker driver to travel to one or the other limit, caused by the DC bias across the terminals. In the case of the implant (which uses lower voltages than an audio amplifier), this will cause the electroplating effect, and the consequent electro-chemical reactions described above. So important is the prevention of plating, the FDA requires all CI stimulations to pass a rigid mathmatical and electrical test where the integral (summation) of the total charge over any 10 minute span must be zero.

One failure mode theory can be pretty much set aside: Dendritic crystalline growth on the circuit chip, which could indeed happen in a matter of days. For this to occur, it would require moisture to be present, which is due to a failure of the hermetic seals in the implant case. One longtime implant engineer told me that dendrites will grow with just a few monolayers of water present and a small dc voltage. The reason we are setting this aside is that if indeed it were true, there would have been dozens, probably hundreds of similar overstimulation failures in the last 6-7 years from the infamous Astro-Seal (“Vendor B”) episode.

Another tantalising possibility is a software glitch in the new SoundWave 2.0 software. The stim software that is downloaded from SoundWave to the processor is supposed to be identical between SW V1.6x and V2.0; but this is one area where bit-for-bit comparisons can be easily verified and ruled out.

[This is not to be confused with the boot-up of the implant electronics package itself: What sets Advanced Bionics’ method apart from the others is that when the implant circuit powers up, large data tables are downloaded from the processor into the implant memory itself as a BIN file, taking 1.5 to 2 seconds before stimulation starts. These data tables contain various combinations of complex electrode firing patterns, which allows for the 88,000 forward data updates per second to take place. There are many software fail-safes built in that cause a graceful shutdown, so this too can be quickly ruled out.]

So, we are back to a component-level failure that causes the output to Fail Ugly. If the design engineers did their job properly, there will only be a minimum of any singular component failure that will cause this nasty overall failure; and more importantly from a reliability standpoint, adding the complexity of additional monitoring circuitry will greatly decrease the overall MTBF (mean time between failures, the reciprocal of the failure rate per million hours).

The open questions Advanced Bionics needs to answer are:

  • Which component failed — Semiconductor, or tantalum capacitor?
  • Was it an open or short failure?
  • Have these failed circuits been attached to 1j or Helix electrode arrays, or to both?
  • Where in the circuit is this failed component located?
  • What is the proximate cause of the component failure?
  • What are the destructive and non-destructive test results from this batch of components?
  • What have been any recent component changes?
  • Have any components been purchased from a new or different vendor?
  • What have been any recent QA/QC changes?
  • Since these are “infant mortality” failures occurring at 8 & 10 days (and perhaps the one at 11 days along with 8 others), why weren’t these detected during incoming inspection or during burn-in?
  • What is/are the manufacturing date(s) &/or serial numbers of the implant batch(es) containing the offending component batch?
  • Is the batch of bad components confined to one manufacturing batch? To one reel?
  • Can this failure be detected with the SoundWave 1.6x or 2.0 tools as released to the CI centers? To the tools issued to the clinicians?
  • Can Neural Response Imaging (NRI) be used as issued to detect and/or confirm this failure? If not, is there a software update to NRI in development?

I just received my AB implant within the last year: Don’t panic, as your implant is probably .NOT. in the batch subject to this particular Ugly Failure. Unless you show symptoms of the painfully loud overstimulation, you’re OK for the moment.

Just to clarify, the implant electronics from the three manufacturers licensed in the United States — AB, MedEl, and Cochlear — all have similar failure rates where they fail gracefully. This recall is totally different, as it involves Failing Ugly.

I’m considering an AB implant: Do I fish, or cut bait?

Once you decide to get a cochlear implant, there are many factors that will go into your choice, as well as the influence (both good and bad) of your CI audiologist and surgeon. If you have not yet read Tina Lannin’s excellent blog articles on CI’s in general, and more specifically on choosing a CI brand, please do so, as it contains very good information.

Our recommendations:

1. Ask your surgeon if s/he implants AB’s 1j semi-curved (lateral) or Helix (perimodional) electrode [But note this one surgeon’s response when he was asked]:

  • If he implants the 1j electrode, then a very good substitute is the MedEl Sonata Ti100 implant with the 31.6mm FlexSoft electrode and the Opus 2 speech processor (either with or without the optional remote — makes no difference). It is our belief that the speed and current steering of the MedEl implant when combined with their FineHearing stimulation software is more than adequate to the task; and since you would be getting a lateral placement with either the 1j or FlexSoft, the longer MedEl electrode combined with the tonotopic matching provided in Maestro 3.x MAP (programming) software (which is .NOT. in AB’s SoundWave 2.0) will provide a better overall experience, especially if a hearing aid is used in the other ear;
  • If he implants the Helix electrode, it’s a tougher call: Even though Soundwave 2.0 does not provide for tonotopic matching (which we consider a major limitation of the AB system), the perimodional (tight spiral) placement does indeed provide a cleaner (purer) stimulation. Unlike brokerage Helvea analyst Daniel Jelovcan’s prediction of the AB implant being off the market for six months, we here at the Hearing Blog believe it will be closer to six weeks .IF. — And only If — the failed component has been identified and has been scrubbed from the implant production stream;

2. If you are the parents of a pre-lingually deafened infant scheduled to be implanted before the age of 18 months, we recommend .NOT. delaying the scheduled implant surgery date, as every day that goes by is that much less auditory and speech development will occur in your child’s brain as it is developing. For this group, The Hearing Blog recommends either MedEl’s Maestro system with the Sonata Ti100 implant connected to the 31.6mm FlexSoft electrode using the Opus 2 speech processor and the FineHearing stimulation software; or Cochlear’s Nucleus 5 system with the 25.4mm Contour (perimodiolar) array and the two-way Remote Assistant for its diagnostics.


We here at The Hearing Blog take no comfort in publishing this article, because cochlear implants are safe, effect… And life-changing to over 200,000 people so far.~

 



← Failing Ugly II: More on the Advanced Bionics Recall Series on FM: Soliciting User Experiences&c. →

About the author

Dan Schwartz

Electrical Engineer, via Georgia Tech

25 Comments

  1. Sue
    November 28, 2010 at 1:35 pm

    Speculation without evidence will not help anyone. Using the term “Fail Ugly” without any evidence to back it up does not impress me at all. I myself was activated one week ago (Advanced Bionics); no problems so far. My son has had the AB implant for 3 years, no problems there.

    This is not information from a reliable source.

    Sue


    • Supervisor
      November 28, 2010 at 3:20 pm

      Sue, Failing Ugly is .NOT. speculation.

      Advanced Bionics admitted five things in the FDA approved patient recall notice:

      1) There were 2 confirmed and 9 more possible cases;
      2) The 2 confirmed failures resulted in overstimulation without shutdown;
      3) The 2 confirmed failures were “infant mortality” in the first 8 and 10 days (100 hours);
      4) The 2 confirmed failures required explanting and reimplanting;
      5) “…Continued device use may lead to damage to the inner ear and/or the auditory nerve.”

      Read the article again.


  2. George
    November 28, 2010 at 11:17 pm

    Sue, please re-read the meaning of the term “fail ugly”, meaning “failing hot”, or failing while still activated with electricity rather than shutting down. (The issue can result in pain, overly loud sounds, and/or sudden shock sensation in the implanted ear while the implant is receiving power. (Quote from Advanced Bionics Recall Notification)) The term “failing ugly” is Dan’s own term, but he did define the meaning for us.

    Please also re-read the rest of the article, and tell us which information is not from a reliable source. I’m not being facetious, I would like to know if you have different, credible sources that reveal different facts.

    Also, I am truly thrilled that you and your son are satisfied, happy AB CI users. Congratulations on your decision to hear the world! I love to hear CI success stories. All the best to you and your son as you continue your hearing journeys.


  3. jay
    November 30, 2010 at 7:32 pm

    I have an AB CI implanted sometime 2000. Now I am having trouble with the implant where it will stop functioning altogether and not come back on for some time. At times when i put the earpiece on it will take a long time to :boot.”
    The doctor’s office doesn’t return calls, so I am stuck with living “deaf.”
    Would I recommend anyone to have a CI? NO DON’T DO IT! Technology is advancing enough to find solutions to at least help severe hearing loss, but what happens when you get an implant and the device inside fails?


    • Supervisor
      November 30, 2010 at 9:08 pm

      Jay, it’s 9PM here, I haven’t eaten dinner yet; so I’m inserting this as a marker. I’ll have a detailed answer for you; but the Short Answer is that it may not be terminal.


  4. Virg Hubard
    December 1, 2010 at 3:16 pm

    Very interesting. I had my first advanced bionic implant oct 10 2006 at the age of 69. It was one of the first defective ones. I was reimplanted Jan. 6th 2009. To date I’ve not had any serious problems just the fact I’m having a hard time getting it mapped properly so I can enjoy hearing again. I hope and pray I will not have to have this one replaced.
    It strikes me odd that the first time the gave notification it came by regular mail. This time fed ex. I wonder why the urgency this time.


  5. d
    December 2, 2010 at 5:13 pm

    Jay
    I am sorry that you are having problems, you need to get in contact with your audiologist. If you dont get anywhere with that, then contact AB. They will help you. But all of the persons I have heard of who had their devices replaced, did as well or better. Just remember you are not alone.

    It doesnt sound like your device is getting a good lock possibly, what that means is the head piece , even though it is sticking to your head. It may not have the power turned up high enough to make the internal circuitry power up thru the extra skin or cellulouse.

    I can say that myu head did change and had to have them change the power setting in the program. It did the trick.

    So I hope that helps.

    d


  6. Robson
    December 16, 2010 at 8:25 am

    You’ll want to add a facebook button to your blog. I just bookmarked this article, although I had to complete it manually. Simply my $.02 :)

    – Robson


  7. Thomas Fennell
    December 29, 2010 at 5:05 pm

    My daughter is one of the two people explanted. Feel free to contact me.


    • Supervisor
      January 18, 2011 at 3:37 am

      Thomas, indeed I contacted you, and since by your IN-ARPA address on the Comcast cable system, you are in Haddonfield or Haddon Township (only 5-10 minutes from my home near the Cherry Hill Mall), I would like to meet you in person to discuss this, if you choose. One of my favorite places is PJ Whelihan’s Pub at 700 Haddon Avenue, on the Haddonfield-Haddon Township border across from where Jay Chevrolet used to be located.

      Although we are not investigating previous failures per se, your report of how CHOP & AB handled your daughter’s failure would be illuminating, as I can sit down with you and quickly ask followup questions.

      You can reach me at Dan@Snip.Net or you can call me at the phone numbers I sent you three weeks ago.


  8. Thomas Fennell
    December 29, 2010 at 5:07 pm

    My daughter may be one of the other cases Im not sure


  9. Thomas Fennell
    December 29, 2010 at 5:25 pm

    Ok my apologies, my daughter was not one of the 2 people who experienced this instant type of failure, however she did experience catastrophic failure and severe pain ultimatly resulting in a reimplantation before this recall was issued and now she is experiencing other painful syptoms with the new implant. We are going to have the device evaluated and tested at Childrens Hospital of Philadelphia were both her surgeries were performed. Her original implant was on Feb. 17, 2000. Her replant was in late Nov. 2008. There is a very long story to this and we were not happy how it was handled by AB or its reps.


    • Supervisor
      December 29, 2010 at 5:57 pm

      Thomas: Please be sure to read the follow-up article Failing Ugly II. Although we’re not investigating earlier failures per se, we are interested in how AB handled them.

      The failure your daughter had in her Clarion 1.2 implant was covered in the first recall over the positioner and meningitis; while the second (2004) and third (2006) were caused by Astro-Seal (“Vendor B”) failures. Whether this “hot failure” in the new (November 23rd 2010) recall also involves a seal failure is not yet fully known; however dendriditic crystal growth implies moisture impingement.~


  10. Jeffrey
    January 6, 2011 at 7:51 pm

    The following excerpt from your post above is inaccurate:

    …The official letter sent to AB CI recipients who have devices from the affected batch/lot…

    The letter went out to all HiRes 90K recipients. The two (still only two identified as of 1/6/11) patients with this issue were implanted many months apart, and the two internal devices did not come from the same batch/lot.

    I’m curious about what new information your investigation into the recall has uncovered. Do you have any previously unreported details, or are you still just extrapolating and speculating based on the general overview information from the recall letter that went out?


  11. Jeffrey
    January 7, 2011 at 10:36 am

    Supervisor,

    Yes, I received the original letter via FedEx (which, in response to Comment 10. made above, is how virtually all correspondence from AB is sent to me) back when it first went out to all recipients and implant centers. Perhaps I’m not reading closely enough and skipping over something, but I’m still missing the part where a specific lot or batch is indicated as being the source of the problem. I stand by the previous comment I made (unless one were to consider all 28,000 HR90K devices to be from the same “batch”). The information I have received is that the failure issue is not related to a particular production lot or batch, because the two confirmed internal devices came from different lots. However, I could swear that an edit has been made to the original post, so it seems that perhaps you are aware of that fact.


  12. Phil
    January 18, 2011 at 2:57 pm

    I find your infomation disturtbing and unfair.
    You never mentioned that AB made a VOLUNTARY judgement to recall the implant and inform FDA knowing that they will suffer losses and bad publicity. For this i applaud their honesty!!!!
    If this happened to other manufactuerers especially Cochlear corp they would keep quiet about any problems and wait to be told to recall by FDA.
    This brings me to a question are you a paid advocate by cochlear or medel?


  13. Cinderella Carmley
    February 10, 2011 at 10:32 pm

    Wow that was unusual. I just wrote an very long comment but after I clicked submit my comment didn’t show up. Grrrr… well I’m not writing all that over again. Anyhow, just wanted to say wonderful blog!


  14. Eva Eveland
    February 21, 2014 at 4:28 pm

    In 2004 my sister had AB Hi Res 90K. In 2010 she started to get major headaches and her device started to make her hearing slurred then came the burning near her implant. Finally in 2013 she found a new audiologist who didn’t like what she was hearing and had a Rep from AB come and test her device, let me tell you if you were in the room when the testing was going on it would of made you cry like it did me. The whole time the AB Rep kept telling her ok i’m going to test you shouldn’t feel anything. As soon as she started the testing she kept telling the rep that she was being burned and the Rep kept saying well that shouldn’t happen then all of a sudden my sister got the shock of her life sent though her whole body it was like watching someone having a defibrillator to the heart. AB does not care they said she needed the device changed out. Funny in the statement we got from the AB Rep doesn’t say one thing about her being burned or shocked. How how can a company make up lies. Were still waiting to get the results back from the lab on what caused her device to fail but i’m sure it wont be the truth. Why cant an independent company be allowed to test the device why should AB be allowed. Also after her surgery she was the 1% to have Face go paralyzed. The truth needs to come out and AB needs to quit lying to the public. Need help on how to sue this crazy company.


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