Bluetooth LE bone conductive implant.

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)


  • edited 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.
  • 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.
  • 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
  • edited 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.
  • I agree that the chironex is talking about.
  • 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?
  • 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.
  • 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.
  • 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.

  • 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.
  • 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.
  • 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.
  • Don't want a transdermal. It'll have to be an inductive charger, even if the size is annoying.
  • edited 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.
  • Where did you pull that silicone tidbit from? I've literally never seen anything to indicate that. Papers? 
  • edited 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.
  • 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.
  • 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.
  • 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. 
  • 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?
  • It's a piezo BCE? They make standard ones, like in the google glass prototypes.
  • 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.
  • 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
  • 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.

  • My blog post about this stuff as of today. More space to put things there.
  • Link appears broken, try this one instead :)
  • edited August 2015
    Love the warning you put in at the end @benbeezy
  • UPDATE: 
    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 
  • You had me at amazon prime....
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