Bluetooth LE bone conductive implant.
  • BenbeezyBenbeezy August 2015
    So I know that people with tragus implants talk about the volume issue. The magnets are kind of far from your real ear and thus don't produce very much sound. My idea is to do a bluetoothLE headset hack with a conductive charger and a bone conductive speaker. 

    and then basically follow this:

    This those 3 things I think I can make the smallest bluetooth bone conductive headset.

    I will modify the charger from the toothbrush with magnets and make sure magnets on on the board, this will allow me to just snap on the charger while I see or something.

    I could also use the headset as a "trusted device" on my phone and my phone will lock if it doesn't see my headset on, and if it dies I still have my other "trusted device" my NFC chip. so I and only I should always be able to unlock my phone.

    What does everyone think?
    Does anyone else want to do anything like this?
    On a crazy scale of 1-10 how bad is this idea? (still going to do it though)
  • McSTUFFMcSTUFF August 2015
    I want to see this work. I use a Bluetooth headset often and I know I would use it more if it were built in. 

    Parts to consider:

    An alarm clock that doesn't wake anyone else up
    SMS to voice
    Security as a trusted device

    No external microphone
    Impedance matching transformer is as large as the device
    Bulky for under skin

    Talk this out and get people with more knowledge than me to show the idea full of holes but definitely pursue this.

    EDIT: Just to be clear, I don't think the inductive charging units I linked are ideal for the final product but as a proof-of-concept they should be great to get started.
  • BenbeezyBenbeezy August 2015
    Problematic fixes:
    the mic can be put inside, since the skin is so thin it should not mess with the mic much at all, but again this is all a test

    The Impedance matching could be an issue, but I'm not sure how load you would need it if its right by your ear. Else we could use a coil and magnet setup that would work alright.

    I'm not sure it would be bulky under the skin, all of the parts would stack pretty flat, I imagine I will need to solder some stuff un a different orientation but I'm to keep it under 2mm thick, and I think that is very possible.

    installation will be terribly painful and not fun, no way around that one.

    I looked on amazon and they do sell silicone spray. used to water proof your tent and shoes. So I am going to be doing some testing on that to make sure its bio safe. (I will be the alpha tester of that.)

    I am planning on using the toothbrush charger because it is much smaller, the adafruit ones (I did look up and thats why I got the toothbrush idea was from them) are just to big. the coil would be 75% of the implant.

    Everything I have so far is just an idea! just so everyone knows. i dont yet have the parts, but from what I know about electronics I'm pretty sure I can pull it off.
  • chironexchironex August 2015
    Ya I feel coating is gonna be a nightmare. Like the only way i'd ever consider getting this thing is if we could make it no more than a 1-2mm thick and 2 is already pushing it for something in your face. Unless it was a whole big pain in the arse and you stash the electronics somewhere else in your head and run wires but that gets ugly and shitty really quickly. What if instead of bone conduction, you implant a small piezo speaker at the base of the ear canal, like the lower portion, under the skin but far closer to the ear. Using one of the new super caps that are coming out you could make the battery flexible which makes coating a bit harder but better in your body. Then you need to keep you electronics package small, say no bigger than a quarter ideally. electronics sits almost under the tragus but further forward, piezo sorta deep into your eat and charging and signal coil around the electronics. Seal the whole thing in silicon cause you'll want this squishy and bendy. No clue if we have the capability to do this. I know there are some medical chips like it though so im sure we could make it work
  • chironexchironex August 2015
    Ok looked at you links. That bluetooth thing is perfect. Like, perfect. That said i think piezo as a speaker vs for bone conduction would require less energy and last longer.

    Edit: just realized what you meant @mcstuff. the impedaance matching transformers are huge. May be able to make a custom one thats smaller though.
  • BenbeezyBenbeezy August 2015
    I agree that the impedance matching transformer is big. I think that will be the main issue on making it. I'm going to do some testing to see if I can do a smaller transformer (less voltage) because its so close to your ear, I am thinking this will be implanted just behind my ear, I used to have google glass and it had a bone conductive speaker in it that sat on that spot and I could hear it plain as day while no on else could. This is a good place because you can put it right on the bone easily and you can hide the bump behind your ear and hair (would need to shave a small section of hair). I think I can make it about the size that @chironex is talking about.
  • chironexchironex August 2015
    Implanting back there is hard though. You need to keep in mind just how sensitive your face is and how much is going on there. Hard to keep clean too. If it's in the ear canal as I suggest I doubt it'd need very much voltage at all, you could probably make the transformer very small. Also is there no solid state alterantive? I thought impedance matching is old school and degrades audio?
  • CassoxCassox August 2015
    Actually, I've done implants behind the ear before. It's a really easy place to work. I've been trying to up my game in terms of procedures and I was studying a bit with a plastic surgeon. Believe it or not, the face is like the easiest and most forgiving area of the body to cut on. Also, you wouldn't place directly on bone. Such an item can still be placed subdermal and cause transduction of signal.
  • BenbeezyBenbeezy August 2015
    I ordered this just to test with, since its very small and cheap, I will get this one working with everything needed and then probably get a better one before the implant.
  • CassoxCassox August 2015
    Ok, a couple things to consider -

    Heat. Small at times equals heat with extended use. Just something to consider.

    Silicone: Don't do it man. Trust me here.. The spray silicone type your talking about is absolutely not implant grade stuff. You might be able to get away with it but I'm not so sure. Furthermore, Silicone does allow for the passage of fluids. Slowly but surely, it will get to your device. Fluid is an issue even with thick thick coatings of the stuff, so a very thin coat will cause your board to be exposed to fluids in no time. The texture of it is good though. You wouldn't want something hard under thin skin like where you're proposing to implant it.
    Consider other options with the coating.

  • BenbeezyBenbeezy August 2015
    Good to know @Cassox , do you have any idea on what would be best? Silicon was the only thing I could think of that would be soft and feel nice.
  • GriskardGriskard August 2015
    My best solution at the moment would be to encase it in a thin titanium shell and coat that with silicone. Gives you the softness of the silicone without the leak factor.
  • MeanderpaulMeanderpaul August 2015
    If you get this thing working count me in! Is the charging port going to be a plug in to you head type of deal? The only thing I could see bad about that (what actually worries me) is do you charge at night while sleeping with a cord going to the Mellon? I see a strangle hazard as I do not sleep sound and roll around.

    I was thinking how about a battery pack that you can put on kinda like a head band that will simply snap in place by magnet or something similar.
  • ElectricFeelElectricFeel August 2015
    Don't want a transdermal. It'll have to be an inductive charger, even if the size is annoying.
  • MeanderpaulMeanderpaul August 2015
    That would be a whole lot safer. would the heat produced from an induction charger possibly cause issues with the skin or a silicon coating. I know the silicon I used on my reptile tanks doesn't hold up to well with heat but that was also not a spray I'm sure your silicon is slightly different.
  • chironexchironex August 2015
    Where did you pull that silicone tidbit from? I've literally never seen anything to indicate that. Papers? 
  • MeanderpaulMeanderpaul August 2015
    Experience. I watched it fail with a heat pad it pealed right off like hot glue and before you ask it sat for 24 hrs

    Edit: I should also add I only had this happen one time with a heating pad and never had it occur again. Whether or not it had something to do directly to the heat or a combination of things I don't know. I thought it may have been worth mentioning since an induction charger produces heat like a heat pad and is active for an extended period of time.
  • chironexchironex August 2015
    RIght, that's a heating pad and I dunno what sort of silicone you're talking about. Im talking properly applied medical silicone. I know @glims had a working method that he posted about. And that aside silicon is the standard for a lot of bendy implants, including pace maker wires.
  • MeanderpaulMeanderpaul August 2015
    Mine wasn't anything special. It was dap from home cheapo. I wasn't trying to off put anything by it just simply add my experience with using a silicone product with heat. My concern wasnt with the use of silicone so much as the heating it up part.

    Not many implants that I have seen talked about produce heat like an induction charger which specifically uses heat which is why I had brought it up.
  • chironexchironex August 2015
    Fair enough. I can't see the small amount of heat that's produced would be a problem. If heat is such an issue I'd be more worried about the surrounding tissue rather than the coating. But if the coil will be a problem seal the main body of the thing in titanium. Then have the speakers or piexo or w.e you use sticking out. Then coat everything in a layer of silicone. The whole thing will make it bulkier but if ya do it right it'll still be very thin and small and unobtrusive. 
  • McSTUFFMcSTUFF August 2015
    Right now the piezo element is driven by a matching transformer due to the high voltage requirement. Has anyone encountered something better for an implantable speaker? Or is there a better way to drive the piezo?
  • ElectricFeelElectricFeel August 2015
    It's a piezo BCE? They make standard ones, like in the google glass prototypes.
  • BenbeezyBenbeezy August 2015
    I am going to try and do things without the transducer, just to see what kind of volume I can get without it. Because the headset in my ear is VERY loud. But if it doesnt work out I am thinking maybe a magnet and coin will be the slimmest way (even though not my favorite) so really just more testing is needed. 

    As for the coating I am thinking of maybe a PTFE coating or something that would flex, something like titanium is very difficult to make and I image not sort on my the head as an every day thing.
  • chironexchironex August 2015
    You could use PDMS. I'd forgotten about it until now. I realise now that is what i was thinking about when I was thinking silicone. Silicone when done well can still be good but pdms, very good. I keep seeing it pop up in implant papers and was planing on using it for the transdermal project. And here's a paper on ways to further enhance the coating so that you can have areas that wont let cells attach so certain parts can remain free floating. link that's just the abstract, if you wan the full thing lemme know. One thing im gonna start pushing for is people to go beyond the standard coatings for things and start looking into ways to make the coatings smarter. It's one of the thing i've been working on a lot lately and it's really cool what some of these things can do. Like if you wanted to forgo a speaker entirely and get super high tech and stimulate nerves you could use boron doped diamond electrodes for example which im working on making. but i digress. For you i'd say go with pdms. It's flexible, biocompatible and can be modified to do all kinds of fun things. And this is how easy it is to handle link
  • BenbeezyBenbeezy August 2015
    UPDATE: I found a old wireless qi charger and got that small wireless headset delivered, I am testing the charging on a different bluetooth headset right now just to make sure it works well and doesn't get to hot. I am using a different one because the real one is going to be a pain to solder the small pins. But it does seam to be working.

    I still haven't figured out how I am going to be doing the speaker/bone thing yet. but I will figure it out once I get some more parts in the mail. 

    I am going to change out the button with a magnetic switch, this way I can use my finger magnets and I don't have to push hard on it to say pair another device or turn it on and off. 

    Size is a bit better that I thought for just this far into it. its just larger than a quarter and maybe like 4mm thick, so not bad at all. The device lasted me all day as a test before I took it apart so I am not super worried about battery life on it.

  • BenbeezyBenbeezy August 2015 My blog post about this stuff as of today. More space to put things there.
  • BirdMachineBirdMachine August 2015
    Link appears broken, try this one instead :)
  • BenbeezyBenbeezy August 2015
    @BirdMachine Thank you :)
  • MeanderpaulMeanderpaul August 2015
    Love the warning you put in at the end @benbeezy
  • BenbeezyBenbeezy August 2015
    1) I am now using the bone transducer and its awesome sauce.

    2) I took the charger board and cut it down and am now soldering onto the test points of the board, this makes the coil the largest part meaning the final shape

    3) I am going to cast all of this in epoxy to hopefully prevent battery issues and to make it easier to implant. Will have a bio coating over that.

    4) I'm not going to put a magnet in it. The bone transducer is strong enough that a charger can stick to that and should sit far enough away that the magnetic switch for it to still work.

    5) I am also putting a NFC implant in it, this will have the device address so you can do tap to pair without having to mess with the switch. The switch will only be for power on/off but could be used to pick up the phone or pause/play music.

    6) I have now make a list of all the parts and they are all amazon prime 
  • chironexchironex August 2015
    You had me at amazon prime....
  • SixEchoSixEcho August 2015
    you should add a magnetic shield between the coil and the rest of the device. otherwise you'll get all sorts of weird currents occurring in the battery and it'll go bad quickly.

     I think your plan to coat and implant this at grindfest is unrealistically ambitious, but I wish you luck. Please stay cautious though. Nobody's put a DIY powered implant in their head before.
  • BenbeezyBenbeezy August 2015
    I do have a shield with the coil already, I'm using the one that came inside the receiver that I took apart. Why i s grind fest so ambitious? I will have it done by then why wait any longer than that?

    I'm stoked to be the first, I hope everyone will see that yes DIY powered implants are possible and not terribly scary. 
  • chironexchironex August 2015
    Cause there's more to making implants then, coat, shove in face, hope for the best. You need to eliminate all corners and anything that's even a little rough. You need to make sure your coating is PERFECT. You need to make sure it can be properly cleaned and you need to have a firm grasp of where it's going into and how you're making it stay there. 
  • SixEchoSixEcho August 2015
    plenty of reasons, safety testing being the biggest one. if you are the first, it's even more important, because you want to set a good example.
  • BenbeezyBenbeezy August 2015
    I have a few of them that I am testing and making sure everything is working in tip top shape, and they are. I have access to a autoclave so things should be very clean, and my coating will almost be more of a case. I'm thinking it will be around a mm thick at its thinnest point. The only issue I am worried about is the procedure its self. I think I've though through everything pretty well, I know its important to do right being the first and all. and I'm pretty confident that I've got this.
  • MeanderpaulMeanderpaul August 2015
    is the pinching of skin between the charger and implant going to cause any problems or is the battery long enough that it won't have to be an every day charge?
  • BenbeezyBenbeezy August 2015
    its depends on how much I use it in the day, I think I will get about 2 or 3 days. It will run 8 hours at full volume.
  • MeanderpaulMeanderpaul August 2015
    That's not bad at all probably comparable to an external Bluetooth then. Have you been able to test the volume as in do you need full or will say half work to hear just fine?( I know it kinda depends on the person)
  • ElectricFeelElectricFeel August 2015
    Should be able to use very low volume. BCE's tend to be very good at low volumes even in noisy environments.
  • BenbeezyBenbeezy August 2015
    yeah I have tested volume, I can head it at a pretty low volume when just pressed up on my head, I can only imagine it will sound even better once implanted because it wont have to go through my squishy skin and hair.
  • MeanderpaulMeanderpaul August 2015
    Very nice that definitely makes it a lot more viable to keep from damaging skin since you don't need to charge all the time constantly pinching.

    Can't wait to see how it goes because I'd love one!

    I may try to replicate you work too ;)
  • BenbeezyBenbeezy September 2015



    Electronics still worked! The headset, and charging still worked on it.

    The transducer got glued in place. I think this can be fixed by putting a thin flexible coat over the transducer before putting on the final hard coating over the entire thing.

    Bubbles in the coating, I know I can fix this by just making my own small vacuum chamber to take all of the bubbles out.

    not smooth right out of the mold. This isnt even that large of an issues, the only thing is that it will take some more time on polishing it all up. I will fix this by 3D printing a mold and coating it in silicone, the print will give it a better shape, and the silicone will give it the smooth surface that I am looking for.

    I am thinking about using a halifax sensor instead of the read switch, this will give me a slightly smaller area, and maybe a better read.

    A smaller coil, I think I will work on ordering a custom size coil, this will cut down on the footprint of the device and just be over all better.
  • CassoxCassox September 2015
    Ben, I'm going to order a lapidary grinder as well. We should be able to make a perfect surface.
  • chironexchironex September 2015
    You'd be better off buying grit powders and doing it by hand then buying the grinder. Those things (good ones) can be cost easily a grand. And hand polishing is easier to control, especially for something that's made of resin and you intend on implanting. Also I worry that use of a grinder, rather than making the coating good from the get go, will make lots of imperfections in the resin that'll cause problems. what would be easier is the enxt time you cast the part, do it in a tight mold so you can fill all voids and it'll leave you with a nice perfectly flat surface. That's how they do it for soft lithography, no reason it won't work for this. Just need a metal mold

  • glimsglims September 2015
    For getting rid of your bubbles, you can also use a sonicator. It does a great job of mixing your coating as well.
  • chironexchironex September 2015
    turn... camera.. 90... degrees. Also that lip on the top edge has to go and the whole thing looks too thick to fit in your face. not bad for a prototype though and now that you've got something you can refine it down.
  • BenbeezyBenbeezy September 2015
    Once I got it or if the mold and found it wasn't working I stepped messing with it, I was going to sand the edges off and Polish the entire thing up. This would have also made it a little bit more thin of a coating on the tip and bottom making it thinner over all.

    As of now I thing I'm going to work on a custom transducer, this way I can get it as thin as possible.

    And yes a new good test, I can see how the resin is going to work and stuff over time now.
  • HelyxHelyx September 2015
    Hey Ben, you said you have a parts list? Could ya post those up or send them to me? I wanna get going on one as well and see if we can solve the resin-block issue.

    Also, I thought of a neat idea involving this and a bottlenose. You could have a piezo sensor on a findertip and have the bottlenose send the taps (in Morse code or something?) via bluetooth to the implant, and then have your pocket computer decode the taps automatically and have this implant speak to you.
    I dunno the applications for this, cheating at cards maybe? But seems like a cool way to surreptitiously communicate.
  • BenbeezyBenbeezy September 2015
    yeah! here you go :)

    everyone is allowed to comment on that sheet and I hope it answers any question that anyone might have for what where or how I get some parts.

    Happy hacking :)

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