Thursday, September 3, 2009
Finding a bike helmet
After a bit of online research I found a helmet made by Fox Racing, model name "Transition," that does not have any strap components in the area of the CI. The price of $50 is reasonable for a bike helmet.
Transition helmet on foxracing.com
It looks in style like a combination between a skateboarding and BMX helmet. I found some favorable reviews noting that it is lighter and better ventilated than similar models.
My idea was to remove a small area of the inner shell at the location of my CI magnet. My goal was to make three main improvements:
1. Safety: A recess in the shell at the CI headpiece location should lessen the impact on the headpiece and internal implant if the helmet takes an impact in that area.
2. Comfort: Eliminate the pressure of the helmet on the CI headpiece
3. Function: Prevent the CI from cutting in and out as the exterior CI headpiece gets moved by normal helmet jostling.
I found one at a local store, and after checking that the inner shell was accessible for some cutting at the general area of interest, I purchased it.
Donning the unmodified helmet confirmed that it put a lot of pressure on my headpiece. It would be uncomfortable and unsafe to wear.
NOTE: MODIFYING A PIECE OF SAFETY EQUIPMENT IS NOT RECOMMENDED BY THE MANUFACTURER. DOING SO VOIDS ALL WARRANTIES AND COULD COMPROMISE THE OVERALL SAFETY OF THE HELMET. DO SO ONLY IF YOU UNDERSTAND AND ACCEPT THE RISKS.
Here's an overlay photo that shows the area in question in my case:
STEP 1: Mark the location
I had my wife use a small piece of white tape to mark the location of the headpiece while I put the helmet on and off several times.
I then marked the interior to match the location.
STEP 2: Excavate inner core for headpiece
I used the tip of a 3/8 inch bit in a standard drill to slowly grind away an area about 1.5 inches in diameter and about 3/16 inch deep.
After donning the helmet and checking that the location was correct, I deepened the excavation to about 3/8 inch and rounded the edges slightly, and made a small bevel in the location of the headpiece's wire attachment.
STEP 3: Excavate for implant (if necessary)
Since I have an AB implant, the implant is about the size of two quarters placed next to each other. I also removed about 3/16 inch in the area of that location which is toward my ear.
I finished it off by smoothing the surface and edges of the excavation by simply rubbing the area with my thumb. The material is relatively soft.
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The helmet fits and feels very comfortable after making the modifications. I was also pleased to find that the helmet curves quite closely to my processor over and behind my ear. Not too close to hit it, but close enough to keep it from popping off easily.
And, as an added bonus, my little boy looks like Dark Helmet in Spaceballs when he puts it on :)
Tuesday, February 10, 2009
To AGC, or not to AGC
AGC is defined by Advanced Bionics as "A dual loop gain and compression system. One loop adjusts the gain to soft level input while the second loop attenuates transient loud input. The dual AGC automatically adjusts patient sensitivity for optimal audibility and comfort." And "AGC automatically optimizes gain and compression to the listening environment. Disabling AGC results in peak clipping and may be situationally preferred by some listeners."
I spent a few hours switching back and forth between my normal program and the test.
Pros (AGC OFF):
- No pumping. Pumping is a side effect of loud transients (e.g. dishes clattering) causing other concurrent continuous sounds to vary in volume. It is really only a minor annoyance when AGC is ON.
- Transient peaks don't squash other sounds. When AGC is ON, loud bursts reduce overall volume quickly, with a several hundred millisecond release time delay. Other concurrent sounds, such as the voice of someone one is listening to, are momentarily lowered in volume which can affect understanding.
- More natural sound in a setting without wide-ranging levels.
- Transient peaks distort easily. The importance of this affect depends on the source. The distortion of a rapid transient peak, like a hand clap, is easily ignored. But with a loud talker at close range, the distortion reduced intelligibility.
- Music quickly turns to a distorted messy mush of sound as volume increases. Awful.
- Soft sounds are not made louder. Quiet speech and other desirable soft sounds are harder to hear well.
I don't think I will be using an AGC OFF setting very often. AGC handles a wide range of situations very well, with only a couple of shortcomings. I think it might be most useful in a controlled sound environment in which there are occasional transient bursts causing pumping when AGC is ON -- such as watching TV while one's child is banging on toys :)
I am almost certain that AGC as implemented in the AB Harmony processor is a full-band process. It compresses the whole signal. I think a future improvement would be to make it a multi-band process, which is what is used in most hearing aids. The benefit is much less pumping and squashing since only narrow bands are normally affected.
I will see if I can find any situations where disabling AGC results in enough improvement to garner a permanent slot in my processor.
Thursday, December 11, 2008
One Year Activation Anniversary
One year ago today my CI was activated. And it has been nearly 8 months since my last post here. My CI hearing has changed and improved significantly since then. Everything is better. Pitch sounds almost normal, music sounds like music, voices are voices. I function almost like a normal hearing person. Only very noisy situations can put me at a disadvantage, but it is still much better than I was doing with hearing aids. I never dreamed that a CI could sound as good as it does.
I haven't need much adjustment to my CI in a long time. My last mapping was in May. I am now using mostly a single setting for all situations:
- IDR (Input Dynamic Range) 75
- Hi-Res-S w/F-120
- 50/50 T-Mic/Built-in Mic
I stopped using my hearing aid in my right ear way back in April. At first because it stopped working. And then I noticed I liked not dealing with the higher frequency pitch mismatch between the two sides. It was like a tug-of-war. Now, without the hearing aid, my right ear just fills in the low frequencies that are missing from the CI quite well. I will probably get my hearing aid repaired next year and give it a try again now that my CI ear and brain have mostly normalized the pitch. I suspect that if I can get them working good together it might help picking voices out of noise.
My CI center closed over the summer (due to the surgeon suffering a severe injury that sadly ended his surgical career), so I requested my medical records. One interesting thing I learned was that I was implanted with the straight array (1j), not the pre-curved array (helix). I thought I was going to get the helix, so I don't know why the straight array was used. In fact, I didn't even know it was an option at the time I was making the choice of CI -- I thought Advanced Bionics had switched to the curved array. Odd, but I'm not complaining, especially considering my outcome.
The T-Mic on my CI failed a couple of weeks ago. Because I use a 50/50 setting, I didn't know what was wrong at first because the other mic was still working. Things just sounded different, and the phone sounded really weak. Once it dawned on me what was wrong, and confirmed by switching to a 100% T-Mic setting and getting nothing, I swapped in my backup T-Mic and all was well again. Fortunately I was just under the 1-year warranty cut-off, so AB shipped me a replacement at no charge.
Back to the grind!
Monday, April 14, 2008
CI 2008 Conference
The conference was not solely about cochlear implants, it also covered various other auditory implants such as brainstem and bone-anchored implants, but I will only be covering the CI related parts. With over 230 presentations roughly ten minutes each in length it was necessary to have up to three concurrent sessions running at a given time -- making it impossible to catch everything. Fortunately it was well organized and I only missed a couple of presentations of interest due to conflicts. There were also over 250 poster presentations in the exhibit hall. I was able to talk to reps from all the major CI companies, posed questions to several of the researchers, and met some really interesting individuals. Four days of MSO (Maximum Sensory Overload) from which I am still attempting to recover!
The topics in which I was most interested were:
- Basic Research
- Electrophysiology
- Coding Strategies/Electrode Design/Mapping Strategies
- Music Perception
- Tests of relatively newly released technologies (e.g. Fidelity 120)
- Analyzing current technologies, looking for areas needing improvement
- Tests of new technologies in development
Most of the scientific studies presented were specific to a particular brand, however a few were multi-brand. All the brands are performing well with no huge differences.
As CI performance has improved, the need for better tests has increased. Some of the easiest tests are starting to see a ceiling effect, in which a significant number of subjects score at or near 100%. While that can be quite satisfying on a personal level, it does not provide useful information when testing existing or new strategies. Other tests don't adequately reflect real-world performance. Many new test methods were proposed and some should work their way into the mainstream in the coming years. So, CI users, be prepared for more challenging tests.
There were a couple of presentations regarding tracking implant reliability. Apparently there are differences between manufacturer's definitions of device failure as well as their reporting methods. Some effort is being put forth to globally standardize CSR (Cumulative Survival Rate) reporting.
Now that Advanced Bionics' Fidelity-120 strategy has been commercially available for over a year, as one would expect it was the subject of quite a few studies. There is some indication that speech recognition in noise, and overall speech discrimination in tonal languages, is improved to a degree using F-120. Studies of music perception were a bit of a conundrum: while there was no significant improvement in objective music testing scores (melody, timbre and rhythm identification), subjective scores for music enjoyment were significantly higher across the board.
Spread of Excitation (SOE) was a hot topic. SOE is the longitudinal spread of electrical energy across the cochlea. SOE can be measured using the return telemetry from the CI, which takes readings from electrodes on either side of a fired electrode (or electrode group). Several studies indicate that narrower SOE correlates with improved speech and pitch discrimination performance. Another study suggests that SOE narrows over time after implantation, which could be one factor why most CI recipients' performance improves over time.
There is also work going on to create stimulation strategies that reduce SOE by applying reverse-phase stimulation to adjacent electrodes. The goal is to improve tonal quality, which could benefit both music and speech perception.
I was glad to find several studies in progress on pitch alignment and mapping. One study used a 3D model of the cochlea and electrode position created from CT Scans to estimate the overall pitch alignment. Another used patient-controlled software to subjectively adjust their map. There is indication of improved speech understanding with a custom fit pitch map.
The prior two subjects are the BIG TWO for me: Pitch Map and Tone Quality. I think they go hand-in-hand. Even though my pitch perception has improved over the four months I have been activated, it has a long way to go and I doubt it will get there on its own. I am looking forward to the day I can sit down at a mapping session and realign my pitch map so that intervals and octaves are accurate. Having improved tone quality should not only help perform that process, it should improve the overall sound quality of the final result.
I was encouraged by the variety and volume of research being conducted to improve CIs. I was also glad to have the opportunity to provide encouragement to a couple of researchers working on my Big 2. And my CI performed like a dream. For the past 10 years or so, before my CI, I would have had a great deal of trouble communicating, and would have completely depended on the captioning (CART system) that was provided during presentations. It was liberating to actually watch a speaker and glance at their presentation graphics, rather than paying most attention to a caption screen. The most difficult listening situation of the conference was during the Karaoke sessions at the Med El booth in the exhibit hall at lunch breaks. They really cranked the volume -- but at least it was (somewhat perversely) entertaining!
If you are interested in reading abstracts from the presentations, there is a PDF file of the conference program book available on the CI 2008 website.
The 11th conference will be held June-July 2010 in Stockholm, Sweden, with the 12th in Baltimore, Maryland in April 2012. Go if you can.
Tuesday, March 18, 2008
CI Research
CI Research Study
Shortly after my January 17 blog post I was contacted by some folks involved in CI research. It seems my interest at comparing and gauging my pitch offset between CI-ear and normal ear, and my experienced attention to sonic detail, could be handy in a research setting. I was asked to be a test subject and I complied like a good Borg. Within a week we had scheduled a one-day trip to the Cochlear Implant Laboratory at
On the day in mid-February, I had a 6:30 am flight out. So it was up at 4:00; to the airport about 5:00; hit the security area about 5:15 – my first time through with a CI. I had brought along my spare processor and I remembered reading that it should not be x-rayed (something about x-rays damaging the microphone element). After filling 4 trays with shoes, belt, pocket contents, laptop, and other contents from my bag, I pulled out the spare processor and flagged a TSA person. Upon explaining the x-ray issue, and showing my handy little CI card provided by Advanced Bionics, I was rewarded with a trip to secondary inspection so my processor could be tested for explosive residue. It only took a moment and the TSA people were friendly. I quickly re-robed and repacked and headed up to the departure area.
I located the gate for my flight and slid into a nearby seat. Most people were deep in their laptops, cell phones or mp3 players, so I felt a little the Luddite cracking open a hardback book. I mostly read, but also spent some time listening to PA announcements and even did a little eavesdropping – both of which were surprisingly successful with my decidedly non-Luddite CI.
At about 6:15 we got the call to board. It was a sold-out flight, but even with that we were ready to go on-time; something else wasn’t however so we were held on the ground for another half-hour. The pilot explained something about the delay but the crappy quality of the aircraft’s intercom put the answer just out of my reach. I could have asked my seat-mate, but that would have opened the door to an entire flight of conversation and I had reading to do; plus old hard-of-hearing anti-social habits die hard. The pilot made up some time in the air and we touched down only about 20 minutes late. I grabbed a cab and was deposited at ASU a bit after 9:00.
Tuesday, March 4, 2008
3 Months Post Surgery
Last time I wrote about post-surgery issues was at the 1 month point. The main things were minor aching at the implant site; possible Eustachian Tube drainage; taste disturbance; occasional slight fullness in ear and slight vertigo. The only one remaining now is taste disturbance. Otherwise I feel great.
This taste disturbance -- and I think disturbance is good term for it -- is quite odd. In the first few weeks after surgery I am quite sure now that what I perceived as drainage from my Eustachian Tube was in fact the result of this issue. Most of the tingly numbness is gone, but I have a constant taste sensation at the back left side of my tongue. It is a combination of sweet and salty. Fortunately it is not overpowering and it does not make food taste awful, just off. I can alleviate it quite a bit by chewing on the opposite side. If I were a chef I think I would feel impaired, but for me it's just a minor nuisance.
I had my 5th mapping a couple of weeks ago. I only needed some minor tweaking to balance things out. We also loaded up some test programs on my spare processor. One with a wider IDR and another with wider pulse width. I haven't had a chance to test them thoroughly, so I have nothing to report yet.
My CI hearing continues to change and improve, though more subtly than the first couple of months. I will cover that in more detail in my next post.
Thursday, January 17, 2008
Mapping No. 4
The first thing my audiologist did was stick me in the booth for some sentence and tone tests. The last time I had that done was for my CI candidacy screening back in October. For many years the sentence test has been a futile and mildly frustrating event. If you are normal hearing and want a simulation, try stuffing some good ear plugs in your ears, set your clock radio to a talk program, put a pillow over it and try to repeat what you hear. The sentence test is a pre-recorded male voice, calibrated to a normal conversational level, speaking random sentences such as, "the two boys played in the rain," or "she put her purse on the table." Sitting in the booth waiting for the test to start, I was subconsciously gearing up for the usual strain when a man said quite clearly something like, "the boy threw the baseball through the window." I easily repeated it. This went on for several minutes. I guessed on a couple of words, and only missed one sentence completely (in which, as my audiologist explained later, the speaker had practically yelled something about "the angry man..."). Four separate tests were run. My scores ranged from 93% to 100%. Amazing. And that was with my old map. Sure, it was in a quiet setting with no background noise to interfere, but I only scored 13% before my CI!
Next up was a tone test. I didn't get a hard copy of the test results but I took a quick look at it. At the lower frequencies, which we kept lower at my last mapping, my threshold was in the 40 dB to 35 dB range. Then it dropped to 20 dB at 2 kHz before climbing a bit to 25 dB at 4 kHz. A 20 dB or lower threshold is considered normal hearing, so I'm doing great. And, again, that was with my old map.
A quick shuffling of cables and I was connected to the Advanced Bionics laptop for a mapping. We decided to keep the same 3 program strategies and just crank the levels. We ended up boosting the low frequencies a bit more relative to the highs on my HiRes-S programs, so I think my tone test would be flatter now. One thing I noticed more than during previous mappings was the distinct difference in the quality of sound when Fidelity-120 is ON or OFF (F-120 is AB's new feature that increases the number of spectral bands dramatically). When F-120 is OFF, my audiologist's voice has a slight "buzziness" to it; when ON it is smoother, more natural.
We finished up the session with a discussion about my right ear hearing-aid and HiRes-P vs. HiRes-S (two different electrode stimulation strategies). She gave me the green light to use the hearing-aid as often as I want. So far I've been liking HiRes-S better, for speech especially, but I still want to spend some time testing HiRes-P. I was listening to some music a few days ago, switching between P and S, and I think P might be better. Also, there is the chance that, once I get more accustomed to the CI, P might be better for everything -- so I don't want to discard it from my available programs.
The number I mentioned in my prior post was... hold on to your hat, or grab your underwear, or something... the total billed cost of my CI, surgery and activation. Sobering, huh? It deserves to be on a t-shirt, or a tattoo. I keep getting things in the mail detailing the breakdowns of all this and each time I hold my breath because they look like bills. Though I was covered under a top-tier HMO and I'm quite sure we only pay a small co-pay, it's still enough to give one the willies. I feel fortunate to have received this magnificent technology, but I also feel very fortunate that I didn't need to take out a second mortgage to pay for it.
Wednesday, January 16, 2008
1 Month Post Activation
Unfortunately, in the following days it became clear I wasn't quite ready for the reduced magnet strength. The head-piece would fall off too easy, just by sitting down or doing anything that slightly jarred my head. Worse, it would constantly lose the communication connection and have to re-sync -- several times per hour at least. It started to drive me nuts! My CI has a very distinctive sound when it re-syncs. First it goes instantly dead. Then, upon reconnecting after about a half second, it makes a deep, metallic, watery, reverberating "PINNNNGGGGGG" that sounds exactly like a sonar ping in an old World War II movie! Finally after another half-second the sound of the world comes rushing back. Normally it's not bothersome at all, but having it happen every 10 minutes or so I felt like I was under attack!
The following week, on Jan 8th, I had my 5 week checkup with my surgeon. He checked my scar, the site over my implant, and took a quick peek in my ear. All looked good. I told him about the head-piece. He checked it and said there would be no problem putting the additional half-strength magnet back in for awhile, as long as we keep an eye on it. It is very important to use as little magnet strength as possible. There is the potential to irritate the skin over the implant if it squeezes too tightly. If allowed to go on too long it can lead to an ulcer, which would mean not wearing the CI for the time it takes to heal, or worse it could become infected which puts the implant at risk. There have been cases in which the implant must be temporarily removed to allow an infection to clear up. He said the skin over the over the magnet toughens up with time and becomes less prone to problems.
Next we had a good little discussion about the pitch perception I have described in prior posts -- in brief, everything sounds deeper in pitch then I expect and in relation to my right ear. He was intrigued by my tests that showed about a half-octave difference the week after activation. I wondered if it had to do with insertion depth and he said it was quite likely related. He confirmed my suspicion that they have no way to precisely position the electrode array to match frequency location, adding that there is evidence pitch perception is not necessarily "hard-wired" to locations in the cochlea and that the brain may compensate over time. I think I might already be experiencing some re-wiring, since some sounds don't seem as deep as they did a month ago.
Finally we discussed my right ear hearing aid. He asked if I had been using it at all. I told him my audiologist had recommended I not use it very much during the first month or so, but that I had tried it for short periods of time on occasion. He explained that in the past they (CI surgeons) had found most users didn't want to bother with a hearing aid in the other ear because the CI sounded better by itself, or the two didn't sound good together. So they didn't encourage continued usage. But now they have made a one-eighty since there have been findings that using a hearing-aid along with a CI has several advantages if the unimplanted ear still has usable hearing. It helps with spatial location, speech discrimination, and pulling sounds from noise. And by keeping the ear functioning as much as possible it can improve the result of a future bilateral implant. I had intended to work at using my hearing-aid again, so it was great to get encouragement from my surgeon.
I like movies. Who doesn't? For the past 5 years, I have always gone to a theater with closed-captions. This severely limits one's options since there are only a couple of captioned screens locally. Once or twice during that time I went to a non-captioned theater and I couldn't understand a word. Last week my wife and I went to see "The Golden Compass" in a theater without closed-captions. Even though I've been doing really well with speech, I had no idea what to expect with a loud movie soundtrack. By the end of the endless previews my hopes were rising. Ten minutes into the movie I practically had to scrape my jaw off the floor. I was getting nearly every word, without straining. I even did some little tests switching between hearing-aid only (loud, noisy, english-as-a-foreign-language), CI only (great!), and both (slightly better!!). My best guess is that I caught about 80% of the dialog, if not more. I never felt like I missed anything crucial. The special effects and music sounded good too. Even though the movie was disappointing I was pretty thrilled.
I was in the shower the other day, cleaning my ears, and I noticed a sound when I wiggled my wet finger in my implanted ear! What? More wiggling and sure enough I heard a deep sounding flutter in my left ear. So I seem to have a little residual low frequency hearing. I will have to run some tests on that in the near future.
I have a big project going on in our little (tiny) front yard. I started it many, many months ago and had to take about 2 months off because of my medical adventures. I am finally back to work on it! It feels really good to be physically active -- and sore in the morning -- again. The sound of a shovel digging into wet decomposed granite is just lovely, "Crrrruuuuuunchhhhhh!"
As a parting gift -- ponder this number: 134861.10
Sunday, December 30, 2007
1 Month Post Surgery
I am pretty well healed up from surgery. The incision scar looks good and most of the dermabond gunk has come off. My ear is just about back to its former position. For the past couple of weeks I am getting more sensation where some skull bone was removed to countersink the implant. It is not painful -- just a minor ache at times. I think I still have some slight drainage from the middle ear through the Eustachian Tube. But since I also still have a minor taste disturbance as well I am not completely sure. The left side of my tongue is mildly tingly and tastes are off on that side. It has improved since the surgery and I expect it will resolve soon. I occasionally have a slight sensation of fullness in my implanted ear. Whether it is due to the surgery or the ridiculous number of colds I'm getting I just don't know. Most of the vertigo and balance issues are gone, but I still don't feel completely back to normal. It is most noticeable when I'm moving around a lot -- just a tinge of a woozy feeling in my head. I suspect if I wasn't having to restrict my activities due to these darned bugs I would be over it by now.
It has been about two and a half weeks since my activation. I've noticed a good deal of improvement over that time. Everything is sounding more natural and I am amazed at how much I am hearing. Pitch is still lower than "normal" but I think that might be changing. Voices known to me such as my wife and boy sound closer to normal, and I am understanding more men's voices which are the most troublesome. If I stick my hearing aid in my right ear I think it is sounding higher than normal. It's hard to tell at this time and frankly I'm not quite sure what the hell is going on as far as the pitch goes.
I have more tinnitus in my right ear than normal. It is like it is complaining about not getting enough stimulation, since I'm not wearing its hearing aid. Either that or not liking its role reversal from dominant ear to subordinate. When I do put the hearing aid in on occasion it sounds loud, gritty and tinnier -- not nearly as clear and responsive as my renewed left ear.
Music still sounds marginally listenable at best. At the start of our road trip for Christmas my wife played a greatest hits assortment of David Bowie on the car stereo. It sounded like covers of Bowie with a deeper-voiced singer, like Andrew Eldritch of Sisters of Mercy! Some songs sounded okay and were recognizable like The Jean Genie and Ashes to Ashes. Others like Heroes sounded pretty awful. What was really bizarre and kind of funny was if we turned the volume up to the point where I could hear it with my right ear as well: it sounded like a strange harmonized duet because of the pitch difference from each ear. Weird.
We had a great time visiting our families. I've long had trouble holding any kind of meaningful conversation with my father and his brother as they are both soft-spoken. Christmas dinner has always been a time of interesting and often funny stories and it has just killed me to miss out on that more and more over the years. I think my first comment at dinner was, "you all are really noisy eaters." To which my uncle replied something like, "well, you've been awfully quiet the past ten years or so." So true. This year was definitely a step in the right direction. I could follow most everything said, with only an occasional request for repetition or help from my wife. And because I was able to actively follow the conversation I could jump in as well. It was really nice to do that. That alone was worth price of admission to the CI Club. I think it is quite hard for normal hearing people to imagine the affects of profound hearing loss. Isolation, disconnection and just feeling like an absolute idiot in the midst of conversation. I feel lucky that I was activated so soon after surgery, in time for the holidays. The only down side was that I still get worn out from the CI before bedtime and had to take it off before we were all done talking. But it was a good reminder of how much better the CI is -- with my hearing aid conversations were loud but I couldn't follow a damn one when we were sitting in a group. I could only converse closely one-on-one with certain people like my mom and sister, and even that was a struggle.
On a final note, I had another good CI experience. Our HD-DVD copy of the Blade Runner 5-disc collector edition arrived last week. We've watched the Final Cut version, the Dangerous Days documentary and most of the other featurettes. It is so cool to not completely depend on captions or subtitles! I am catching a great deal of dialog now. I still need the captions on occasion but I can mostly keep my eyes on the movie now. I used to get really pissed off when special content on DVDs was not captioned. They are usually interviews with crappy sound quality and I could rarely follow any of it without captions. Other than the five Blade Runner versions and Dangerous Days, none of the added material on this disc set is captioned. I still think that sucks, but with my CI I can now understand the majority of it -- that's a huge change for me. And for the record, Blade Runner looks extraordinary in Hi-Def. One of my favorite movies.
I have my 3rd mapping this coming Wednesday. I run most of the time at the normal 12:00 volume position. I'm still liking HiRes-S better at this stage (I am not sure that would be the case if the pitch was closer to normal). I don't think I'll need a lot of adjustment this time. But who knows what my audiologist has in store for me?
I'm sure this will be my last post for 2007, so... Happy New Year!!
Thursday, December 20, 2007
Mapping No. 2
NRI is an automated testing function that uses the bi-directional capability of the implant to read actual nerve pulses using electrodes adjacent to a fired electrode. Not only does the processor use AM radio waves to power and signal the implant, the implant also communicates back to the processor on an FM band. I think a new map can be created using the NRI results, but I'm not sure about that -- I'll follow-up later when I find out.
The new map has helped quite a bit. Voices sound more natural and everything is crisper. I went a little overboard on the levels so I am currently running at a volume level of 10 o'clock to quiet things down. But that's good for now and leaves me more room to boost it between now and my next mapping if necessary.
I still perceive sounds as deeper in pitch. Adjusting the levels of the bands helped, but that's not the same as shifting pitch. For example, you can adjust the emphasis of particular frequencies with a graphic equalizer, but a 1000 Hz tone will still be a 1000 Hz tone -- just softer or louder. There doesn't appear to be any capability in the processor software to actually alter which center frequencies are mapped to which electrode. Maybe that's something my brain will compensate for over time. To get a reference for where I am at now, I fired up my audio editing software which has the capability to generate sine wave tones. My right (unimplanted) ear has a fairly flat 75 dB loss, so I can still hear a broad range of tones if loud enough. My test involved playing tones to my implanted ear, memorizing the pitch, then playing tones to my other ear and adjusting the frequency until I found a match. Sure enough, I am perceiving sound in my implanted ear about 1/2 octave below the source. For example, a 4 kHz tone played to my implant sounds like a 3 kHz tone to my other ear. I measured about a dozen tones from 50 Hz to 8 kHz. All were shifted down about the same percentage. Also found that the low cutoff is below 50 Hz, and that source frequencies between 50 and 80 Hz cause a buzzy low pitch. At about 90 Hz the buzzing stops. Between 90 and 200 Hz it's a little fuzzy. The first pure tone is 220 Hz. I noticed that some tones in the 50 to 300 Hz range have a phasing, undulating characteristic which might be the cause of the "wooshiness" I get with traffic noise and other continuous sounds. At the top end, the high cutoff is above 8 kHz. Source tones from 6 kHz to 8 kHz sound the same, probably mapping to the same last (outermost) electrode. Due to the shifting down of pitch, the highest actual frequency I hear at this time is about 4500 Hz. I am very interested to see if this changes over time.
The pitch thing is interesting to me. It seems that most people report the opposite -- that everything sounds higher, tinnier. It makes me wonder if it has to do with the position of the electrode array. I don't know for sure, but I would think there is some kind of reference point for the surgeon to know how deep to place the array. But given differences in physiology from one person to the next it seems like that would only be an approximation. A millimeter or two one way or another from the actual "true" match of a place-code frequency would cause the sound to be perceived higher or lower -- at least initially. In my imagination I see mine being just a tad deep, which I believe would map frequencies lower. I am just conjecturing here because I've never run across the issue in my readings.
One week into this I am extremely happy where I am at. I had a 45 minute conversation with my sister on the phone this morning using my CI - my first! I understood almost everything she said. Bit by bit it's getting better and better. Listening to NPR radio in my car I can understand everything when it is one of the female reporters. It's more iffy with the men -- it depends on their voice. If their voice is deep and less crisp I struggle. I still take my processor off for an hour or two in the middle of the day. The top of my ear where the ear hook hangs is still tender, but getting more tolerant. By the evening, a little before bedtime, I am ready for an auditory break. It's a lot of work listening at this stage. It's nice to take it off, put my hearing aid in my other ear and go back to a quieter world. By morning I'm ready for the full sound load again!
This is probably my last post before Christmas. We'll be leaving in couple of days -- off to see the families for a few days. It should be an especially Merry Christmas this year! I'm looking forward to being able to catch dinner table conversation again!
Happy holidays to you all!
Friday, December 14, 2007
Activation Day Video (Dec. 11, 2007)
Thursday, December 13, 2007
Mapping No. 1 (with photos)
As we cranked up the output the CI started cutting out. After a call to Advanced Bionics my audiologist set the transmission power (the strength of the signal from external to internal coil) to high and that solved it. It is likely due to the swelling at the magnet point and we should be able to set it back to normal in a few weeks. In the meantime my battery life will be reduced somewhat. I'm using the smaller battery at this point to be as easy on my tender ear as possible (it's only been 2 weeks since surgery after all!). Even so, I got at least 10 hours out of it yesterday. I will find out today how long it truly lasts.
The overall nature of sound to me at this early point is that everything sounds deeper pitched, especially voices. I expect that to change over time, but right now it is really weird! My 2-year old son indeed sounds like a munchkin! Many environmental sounds are fairly close to normal: keyboard keys clacking, my footsteps through our creaky old wood-floored house, water dripping and gurgling, and all the various clunks and clacks when doing things. I don't notice the lower pitch as much with noises, but they are lower. Cars driving by sound like wooshing alien spacecraft! Well, what Hollywood imagines they sound like anyway.
I had a really cool moment yesterday. I thought I'd go back and have a look at Abbie's activation video. When I watched it in the past, even with my hearing aids, I could not understand a single word said in the entire video (which is the usual case for me with any web video). Well, yesterday I caught nearly every word! Even her audiologist off-screen! I never expected that a CI would help me with that so soon.
I'm having lunch with a friend shortly. It will be interesting to see how it goes!
For those interested in the technical details (like me!), here are my three program settings:
1. HiRes-P F-120 / IDR 60 / P-mic 50%, T-mic 50%
2. HiRes-S F-120 / IDR 60 / P-mic 50%, T-mic 50%
3. HiRes-P F-120 / IDR 60 / P-mic 0%, T-mic 100%
I need to learn a lot more about the technology, but here are some short definitions:
HiRes-P: Electrodes pairs are fired simultaneously (I think the "P" is for parallel -- 12/17 correction, "P" is for paired).
HiRes-S: Electrodes are fired sequentially (very fast!).
F-120: Fidelity 120 is AB's new strategy which uses current steering to stimulate nerve areas between electrodes. So instead of having just 16 stimulation points (one for each electrode), there are additional points between electrodes providing up to 120 "spectral bands."
IDR: Input Dynamic Range. This is input compression that squeezes the dynamic range -- loud sounds are reduced and soft increased. The higher the number the less compression. 60 is the default and is a moderate setting. I'm pretty sure it's a dB (decibel) figure.
P-mic: The processor's built-in microphone.
T-Mic: An auxillary microphone at the tip of an earpiece that locates the mic in the ear in order to make use of the external ear's sound focusing capability.
My audiologist instructed me to try both HiRes-P and HiRes-S to see if I develop a preference.
Now for some photos. My ear continues to recede back to its normal position. I'd say it's just over half way there!
Here is the same photo as above marked up to point out the various components and with an overlay of the implant showing its approximate size and location under my scalp (you can click on the pictures to see a bigger view):
We took some video on my activation day, so I will work on getting that posted soon.
Wednesday, December 12, 2007
CI: The Surgery Day (Nov. 29, 2007)
The weeks leading up to surgery were a lot more stressful than necessary. About 3 weeks prior, a small sebaceous cyst I’d had for years suddenly became enlarged and infected. Elective surgeries are usually postponed if there are any existing infections. It took 15 days of antibiotics and having it lanced to get the infection under control. Then with 2 days to go until surgery I started to feel like I was fighting a bug. No fever, but slightly achy with a scratchy throat. If that progressed into stronger symptoms surgery could get cancelled.
My surgery was scheduled for 10 am and was instructed to arrive at 7:15 am. The night before I made sure I had everything in order. No food or drink after 10 pm. I had picked up my prescriptions for painkiller (vicodin) and antibiotic (keflex) the previous day. I normally wear contact lenses, but those aren’t allowed for surgery so I decided to remove the left temple piece from my eyeglasses in advance. While doing that the small jeweler’s screwdriver slipped off the screw and skewered my thumb – ouch! Nice little blood sample. Later on while shaving, I sliced my lower lip and bled some more. I decided to skip trimming my fingernails. I slept better than I expected since I was jittery about waking up with the bug I seemed to be fighting starting to blossom. The next morning I woke feeling well and my wife and I arrived at the hospital on time.
The check-in process went quickly and we were up to my room by 7:30. We were introduced to my nurse. She said I should expect to be wheeled to surgery staging about 9:30. Here are a couple of photos from that time.
The geeky one-temple glasses:
Note the sliced lip:
About 8:00 blood was drawn for tests. They asked for a urine sample if possible. I shouldn’t have pissed that morning, because with no fluids in almost 12 hours there just wasn’t anything new to provide. The nurse said after I was IV’d for awhile later that might change. After that I was fitted with stockings and pump leggings that would help prevent blood clots, since the surgery could run 3 to 5 hours.
About 8:15 a different nurse tried to get me IV’d but gave up after a couple of failed attempts saying, “I only stick twice.” Around 9:00 an IV specialist got me hooked up in one shot. After a half-hour on the drip I was able to provide my sample.
At 9:30 the nurse came in and told us that there was about an hour delay in surgery, so more thumb twiddling and watching the storm clouds gathering out the window. Heavy rains were predicted for the next 2 days. We were hoping they would hold off until after we drove home later that day.
A bit after 10:00 I was wheeled down to surgery staging, where they gave me a lovely cap and placed a sticker on the left side of my head. I was happy about that – I had considered writing “not this one!” behind my right ear the night before.
A nurse went over some paperwork with me. Then the anesthesiologist came by to go over the process and asked for a baseline ECG which was taken a little later. When one of the nurses told me it shouldn’t be much longer I realized I was starting to feel like I needed to take a crap. Great – all dressed for surgery with an IV hanging out of my arm. I mentioned it to the nurse and she said if I really needed to go I should, but otherwise don’t worry about it. While I was pondering that big decision my gurney driver arrived about 10:45. He huddled with the nurse for a moment and then off we went with him saying he was going to detour by one of the restrooms for me. In hindsight I am very glad we did that. During the first few hours after waking from surgery, taking care of that business is the last thing one wants to deal with.
As we rolled into the operating room I recall seeing about 4 people: my surgeon, the anesthesiologist, and a couple of others. I’m glad they let me wear my hearing aids and eyeglasses into surgery so I could communicate. One person brought a box labeled “left cochlear implant” up to me for my confirmation. I gave them a thumbs up and pointed at my left ear. Next I was slid over to the firm, narrow operating table. I laid there for a few minutes, glancing around at the variety of equipment in view. My surgeon leaned over me to say hi and gave me a friendly smile. That was probably around 11:15 am. The next thing I knew I was waking up in recovery, which I’ll get to later.
The surgical technique my surgeon uses was developed at Nottingham University Hospital Cochlear Implant Program in England about 4 years ago. My surgeon has been using it for over 2 years. The 2 main differences from other techniques are the location and size of the incision, and that no sutures hold the implant processor in place. The incision is only about 1.5 inches long, set about a half inch back from the crease of the upper portion of the ear. As with all CI surgeries a shallow divot is made in the skull to hold the processor. I was instructed not to rub that area for 30 days because it would be possible to dislodge it until scar tissue developed which would firmly hold it in place thereafter.
The surgery itself took a little longer than normal due to some boney growths in the mastoid region that slowed the process of making an access tunnel into the middle ear. However once that was achieved the insertion of the electrode array into the cochlea went smoothly. After the implant was in place it was hooked up and a series of tests run to ensure it was functioning correctly. I believe they monitor brainwaves and a middle ear muscle to obtain responses to the tests. Closure of the incision was done with sub-dermal sutures, but no surface stitches. Dermabond was used over the top of the incision. It’s a fancy Krazy Glue that both holds the wound together and forms a water and germ proof barrier.
Surgery was completed between 3:30 and 4:00 pm. My surgeon visited my wife in the waiting area around 4:30 to let her know everything went very well and that I was awake and smiling in recovery. I certainly don’t remember that! The first thing I remember was becoming aware that I was lying inclined on a gurney in the brightly lit recovery room around 5:00, that my left ear had some pretty loud roaring tinnitus, and that I was woozy as all hell. I think there were a lot of other patients recovering in there but I had no desire to focus on anything at all. A nurse came by to check on me and I told her I would probably need to vomit soon. She put a towel on my chest and I had a couple of token pukes. Unbelievably, even though I was nauseous the next day or so, that was the only time I barfed. I think I dozed on and off for a little while longer before they wheeled me up to my room around 6:00.
I was very happy to see my wife when she walked in the room. She had a big smile for me and told me everything went well. I’m sure I was informed of that earlier, but that’s the first time it registered. What a relief. At that point I took a little inventory of my state: No specific pain, just a slight throb; intermittent roaring tinnitus in my left ear, loud but not painfully so; my right ear seemed stuffy and I wasn’t hearing well out of it; still woozy and nauseous; the outside edge of my right arm from elbow to pinky finger was very numb; the left edge of my tongue felt tingly, half-numb. So not feeling all that great, but happy all the same.
Around 6:30 my surgeon dropped in to check on me. He reiterated what my wife said regarding the surgery going well, adding that he felt it would be better to leave the dressing on overnight due to the later end of surgery then planned, and that I should be able to go home in a couple of hours as long as I was steady enough. I mentioned the numbness in my arm and he said that was from lying on my arm for so long during surgery, and that it would clear up over the next couple of days. After the good doctor left a nurse brought a food tray. I sucked on some ice chips and nibbled on red jello, which tasted intense. There was a bowl of broth, but just bringing a spoonful within range of my nose I knew I wasn’t ready for that! So I just stuck to ice, jello and warm tea for the next couple of hours. At some point the leg pump device started to get on my nerves. It would pump up and squeeze my legs every 30 seconds or so and the regularity of it became annoying. I was really glad when they removed it.
About 8:30 my nurse gave me a final dose of anti-nausea medicine through the IV in preparation for my departure. A few minutes later she helped me to my feet and guided me to the bathroom. I felt wobbly but was able to stand by myself and pee. Apparently I passed the test so they unhooked me from the IV, set me in a wheelchair and wheeled me out to our car just after 9:00.
Fortunately the rain storm hadn’t hit yet, so we had a quick 10 minute drive home. The first thing I did when I got home was put my contact lenses in. Wearing eyeglasses always makes me feel slightly “off” because I wear them so infrequently. I was also bothered that the hearing in my right ear was so bad, but at that point just hoped it would recover overnight. For the next couple of hours I was still fairly nauseous, but was able to start nibbling on a banana and had some chicken broth later on. I took a vicodin at 11:30 and when it started kicking in I felt better. I slept in 2-3 hour stints, taking a vicodin every 3-4 hours.
The next morning it was raining cats and dogs. I got up around 8:00 feeling better, though still a bit wobbly. Not spinning vertigo, but an unsteady feeling especially if I tilted my head. The hearing in my right ear had recovered a lot, which was a big relief, and the tinnitus on the left had abated somewhat as well. My stomach had settled down enough to have a light breakfast. About mid-day we headed out to see my surgeon at his office. He removed the dressing. The top of my ear was sticking way out – it made me laugh! He said that was normal and it would go back to its usual position over the next month.
I think I covered most of the subsequent recovery in my other posts. Following are photos from the recovery period.
These were taken within a couple of hours of removing the dressing the day after surgery, before the swelling started:
The following are from 2 days after surgery, about when the swelling peaked:
Tuesday, December 11, 2007
Activation Day!
Other notes:
The sound quality this first day has a distinct electronic sound. Sort of a flanging effect. Footsteps and keyboard clicks have a little "boink" to them like water dripping. Voices are tending to sound deeper to me than normal. No munchkins, but a little weird all the same.
We had to install the strongest magnet to get it to stick, probably due to residual swelling since it's only been 12 days since surgery. I should be able to change to a weaker magnet in a few weeks. It needs to be as weak as possible to prevent irritating the skin over the implant.
I'm not wearing a hearing aid in my right ear for a few weeks to allow my brain to focus on adapting to my new left ear.
Friday, December 7, 2007
8 Days Post Surgery
I had my one week post-op checkup yesterday. My surgeon was patient as usual and answered my long list of questions. The main thing that had been bugging me was the slight drainage I was feeling from my Eustachian tube. My imagination and web research had been running a little wild and I had convinced myself I was having a leak of vestibular fluid from my cochlea. That is an uncommon problem after CI surgery which sometimes requires a second surgery to block the leak. As it turns out, I have a small blood clot in my middle ear from the surgery, which could be seen through the ear drum with an otoscope, and the drainage is most likely a byproduct of the clot breaking down. Nothing to worry about and it should resolve itself in a week or two. The otoscope was connected to a video monitor so I could see too. I had forgotten how transparent the ear drum is: we were able to see a part of the electrode wire snaking through my middle ear! Thankfully I can't feel it -- I don't think I'd like that! The rest of the checkup went well. My incision is healing well and I seem to be on track.
Yesterday and today have been really good days. Other than the persistent sore throat and a touch of vertigo I feel good. I only have a slight tightness on my scalp on the surgery side. Most of the swelling is gone and the top of my ear continues to recede back into its normal position. I haven't taken anything for pain since Tuesday. I continue to sleep inclined because I feel a bit too much pressure if I lay flat, but I don't think that's going to last much longer.
I expect my next post to be a detailed recap of the surgery, as promised.
4 days until activation!
Tuesday, December 4, 2007
5 Days Post Surgery
I'm sitting here with my parents. They have been here since the day before surgery and have been a HUGE help to us -- and of course my son is in grandparent heaven! My wife had to go back to work yesterday so it is especially nice having them here now. They are planning on leaving tomorrow but I might just try to talk them into staying a couple of more days! I'm just now getting the chance to enjoy their company and could use a couple of more days of it.
I am amazed at the lack of strong pain so far. I took my last vicodin on Sunday night. I've been taking Aleve (otc naproxen) every 8 hours since then. I haven't had one now for 10 hours and all I feel pain-wise is a very minor earache so I am going to wait and see if I need any more painkillers at all. My doctor told me to ice the side of my head using frozen peas in a latex glove hourly for 10 to 15 minutes for the first few days. I did that religiously through yesterday. At night I woke every 2 hours to ice. Today I cut back to icing every few hours. I have also been keeping my head elevated at all times, which (surprise) isn't that hard during waking hours. In bed I have been sleeping inclined on three pillows with a fourth under my knees. It's comfortable but I'm starting to get sick of being in one position all night.
The tinnitus has subsided back to just a bit above normal, so not very bothersome. I still have some vertigo. I took a few walks outside the past couple of days and just don't feel as steady as usual. It's most pronounced if I tilt my head to the side or back. Thankfully my stomach has settled down and I have an appetite again. I'm sure my wife and parents are glad too -- the first few days I was so sensitive to smells I made them change several meal plans.
Thank you everyone for your comments -- they really help! I have lots of notes and pictures from the past days and expect to get a more detailed post up by the weekend.
Sunday, December 2, 2007
3 Days Post Surgery
One thing that has been great is that we live only about 10 minutes from the hospital were surgery was performed and 20 minutes from my CI center office. On Friday, my wife drove me to the CI center and my surgeon removed the bandage. He said it looked great, surgery went great (though it took longer than normal because of some boney growths he had to deal with), and that I could set an activation appointment for 10 days post surgery. Wow! I was surprised it will happen so soon. My activation appointment is set for Monday, Dec. 10th, with a follow up mapping the next day.
Overall I think I'm doing well. The pain is manageable. Starting Thursday night I was taking a vicodin every 4 hours. Friday went okay, but by late Friday night I was getting too loopy on it. So I started using ibuprofen, with just an occasional vicodin when the pain surfaces. I'm icing my head almost every hour for ten to fifteen minutes. At night I wake every couple of hours and ice it. The swelling seems to have peaked. But I'm expecting to get hit with more pain in the next day or two based on others' experiences.
I think there is some very slight drainage from the eustachian tube on the implant side. Not bloody. Tastes salty. Do any of you implantees recall having that? I imagine with all the work done in the middle ear it would be normal to have some drainage. Also, my throat is still a bit raw from the breathing tube so it could just be post-nasal drip associated with that I suppose.
Friday, November 30, 2007
Post-surgery update
Wednesday, November 28, 2007
CI: 1 day out – what is it? (Part 1)
Just what is this new piece of shiny that will be forever embedded in my head?
Another angle with a nickel for size reference:
The function of that beautiful thing is to send electrical pulses down the electrode wire to the array. The coil receives both power to operate the implant and the digitized processed audio signal from the external processor, via an external coil. Both coils have magnets in the center to hold the external one in place.
Each of the sixteen contact points on the array are driven by a separate output circuit, which allows multiple contact points to be fired simultaneously (I will cover why that is a good thing in part 2).
How does it get implanted? First, here’s some artwork showing the placement of the implant:
Tomorrow my wife and I head to the hospital for a 7:15 am check-in. Surgery is scheduled for 10 am and usually takes from 3 to 4 hours. I’m not sure I have the exact sequence of events right, but the general flow of events is as follows. A small incision an inch or so in length is made just behind my left ear, which is then spread open. To accommodate the processor, a shallow divot is drilled into the area of my skull back from the ear a bit and about level with the top of the ear. Next some bone is removed just behind the ear allowing access to the middle ear and cochlea. This is a delicate process since a main facial nerve is located there. Electrodes attached to my face are monitored to help ensure the nerve is not affected. The processor is inserted under the scalp and muscles. A small opening is made in the cochlea and the electrode array is fed through it. Once everything is in place, several tests are run to ensure the array is stimulating my hearing nerve. My ear is put back where it’s supposed to be and the incision is closed up. Some nice goop over the incision creates a protective water-impermeable barrier and a big pressure bandage goes over that. Then it’s off to the recovery area to be monitored until I wake up. After about an hour I’ll be wheeled to a room. If I’m not suffering any nasty side-effects like bad vertigo, etc., after a couple of hours they will remove my bandage and kick me out the door at about 5 pm.
The following few days I will spend at home popping Keflex (antibiotic) and Vicodins for pain (if necessary), and following the instructions I noted in my previous post. And I will do my best to chronicle the recovery process here.
Now, it’s time to go have my last meal for the next 24 hours. They like you hungry for surgery!