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Implant stimulation, hearing aids, and coil watches.

So this post is basically me exploding all of the ideas that have recently come to light and how biohacking can merge with another field. So, let me know if I end up making NO sense at all.

My mom is hard of hearing (legally deaf) and uses hearing aids, sign language, reads lips etc. Hearing aids have a mode on them called T-coil or Telecoil which was originally developed to help hearing aid users on cellphones. The concept behind T-coils is that the microphone within the hearing aid is used to receive electromagnetic signals instead of sound. Back in the day of brick phones, the mic and speaker in phones utilized big magnets that created big EMF. So they helped hearing aid people talk on the phone. Sadly, today's electronics are much more efficient and don't spit out as much EMF. But most phones still have a mode called HAC (Hearing Aid Compatible) that allows for the use of T-coils. I turned it on and called my voicemail and voila! I could feel the automated messenger lady vibrating in my magnetic implant (in my ring finger). Given the fact that I've only had magnet powers for a month, I can only imagine that this'll become more sensitive as the nerves grow back.

Today, along with a techno-buddy, I built a small EMP generator using a disposable camera's capacitor, a AAA, and some old earbuds. The earbuds have a coil in them that acts as the EMF antenna, firing out the pulse.

First, we tested to see if I could feel the pulse at an inch away and I felt nothing.

So we moved on to 3/4 inch, where I could feel the pulse. Sadly, no exact measurements, but a successful build at least.

Half inch.

Quarter inch. At this point, I could feel the magnet in the earbuds pulling on my finger.

Point blank.

Then, having confirmed that the coil worked, we tested to see if it was creating an omnidirectional field or if it was directional. Sadly, as we expected, it was bidirectional, shooting EMF both forward and backward, but not to the sides.

So, even though these tests were redundant to many of you (and subjective, and flawed ((we had a lot of unwanted arching)), and inconsistent), they showed us a couple things. One, a pulse of EMF can stimulate a magnet implant without pain and work as a sort of notification. Two, EMPs are not omnidirectional. Three, even with a crappy pair of headphones and a camera capacitor, a distance of 3/4 inch can be traversed without substantial EMF dissipation.

These tests will hopefully lead to future endeavors including a magnet stimulating watch and possibly a full room wireless magnet stimulation system.


Displaying comments 1 - 30 of 47
  1. So, would there be a way to shield one side? I think that you should be able to do that easy enough. The next question is can you make it omnidirectional?

    Good testing! First time I've actually seen someone measure field strength on here....
  2. Try using Mu Metal or making a small variant of a faraday cage, with shielding at the back, and a wire running to ground. Or maybe a reflector, if such a thing is feasible.
  3. Mu or even a halbach array?
  4. We're not super worried about the directions yet, because the first thing we want to try is coiling around the wrist, like a watch, to create an EMP toward the finger. Once we do that and test different hand positions, we'll know how much of a problem the direction is. We may also do an test to see the max angle from the coil, similar to this test but with a protractor in place of a ruler.

    But before even that happens, we definitely need to create a bigger pulse. We guesstimated about 9 inches from wrist to magnet for a watchband coil and at this point we can't stimulate from an inch away. Improvement is required.

    In order to be stronger, we obviously need to build our own solenoid with more coils than the headphones have and with a higher current. Beyond that, it's all about testing. Fun stuff though.
  5. How could i make something like this, I want a standard 3.5mm jack end, so i can put it into devices with that socket, pc for example. 

  6. That depends on what kind of output strength you want.
  7. To feel it at an inch or two, would do.
  8. That's what... sigh... i'll be in the corner...
  9. I like this project! And I would think with a purpose built coil you could get much better results.
  10. I would actually recommend hooking up a tighter solenoid to a function generator, or even just an amp with a good amount of power and throwing some different waveforms at it.
    Interesting things to figure out would be the resonant frequencies of your implant, the reluctance period and the minimum field strength for a tactile response.
    The orientation of the magnet would have a huge impact on the use of a wrist mounted EMF source, which makes it an interesting design challenge, considering that the magnet is very mobile relative to the source.
  11. Could you describe the simplest way of feeling sound played from your PC? 

    It's what i want but i've got no idea.

  12. The simplest way to feel sound coming from your PC in an implanted magnet? Assuming it's in your finger, you would need to know the polarity and line up a coil with the axis to have a hope of a sufficiently strong response. All you would need is a strong enough speaker along the axis to pick up the signal in theory, but I don't know the responsiveness of the magnet. The simplest way to test it would be to hold your implant aligned over a larger speaker like a subwoofer while it's playing, and see if that picks up anything.  If it works, you can rip the cone out of the speaker and put the voice coil assembly under the top of your desk where your hand usually is.
  13. just google invisible headphones, it costs about 15$, but you can make one yourself for like 3$ if you know how - you need amplifier (DIY or 1,5$ from china) and coil. there are some guides on it.
  14. I could try to build that, but if i could pay 5$ from China then i would.

    Tried to see if a guitar amp would work, couldn't feel anything other than air moving. So i took the thing out, and i can feel it near the actual coil. 

    with overdrive on, you feel it harder, but the coil gets hot.

    The guitar amp is a bit big, a little usb powered would be better, do they exist?

    Little like the one made in the video, a search for amps, just brings guitar amps. 


    When I say I'd pay $5, I'd pay in GBP.

  15. the guitar amp is too weak, I dont know the numbers but I think its 20 gain max, you need at least 200. I found this one being probably the cheapest you can get unless you want to buy all the parts and make it yourself. But I dont have any experience with this amp so you would have to figure out where to connect the batteries and coil. If you do this please post guide how to connect them, I plan to order this summer and make some $$ selling invisible headphones to students and I may make smaller coils for magnet implants (maybe build a ring that would play)
  16. also try searching 200 gain amps if you dont want to search for guitar amps, which are too weak.
  17. It's not the gain specifically he needs, it's the magnetic field. The strength of the magnetic field is what will provide the force to vibrate the embedded magnet. For an application like this, the electromagnetic strength in the coil is relative to current. The amp you're looking at, the LM386 can only output about 125mW. A household guitar amp can usually push between 5W and 15W.

    However, an LM based circuit would PROBABLY work for a transmitter within an inch or two. The difference between the magnet in your finger and one on say, a speaker is that the fields won't be aligned as well, and your magnet is not going to be able to move freely. I'd have to run some tests on someone with a magnet to really get some solid numbers as to how much of a field it takes to get a tactile response. It's all very subjective as well. How much force does it take to create a compression wave in your flesh? How sensitive to it are you?

    It's definitely doable with household parts, I probably have most of those parts around somewhere.

    I definitely plan to get a magnet and become active in the haptic subgroup, so if anyone wants me to try and build a tactile magnetic bumper like the bottlenose, I'll give it a shot.
  18. well, there's that guy with magnets implanted in his ears and in one of his videos it shows him having coil around neck and listening to music, so I guess it's strong enough. I also plan on making "ring" that could make you feel the music, but thats too far away (good thing is that if you had this ring and put finger in the ear you could have portable low quality headphone)
  19. I looked up that video. Pretty neat, you can see he has some serious power going through the coil, for a neck mounted system at least. It can definitely work.

    Good idea with the ring and fingerphone idea, that's clever.
  20. Is it normal for the coil in a guitar amp to heat up?

    Why does the neck coil not heat up? size? the coil in the amp would be moving under normal operation, would that cool it?

    Would a ring coil heat up? ring as in jewelery. Or a bracelet, mentioned somewhere before.

  21. I think they work differently - the guitar amp is powered by electricity from outlet (230 Volts in Europe), the chinese or the homemade one is powered by 9 Volt battery. I think the Voltage makes it hot but don't take my word for it.
  22. The current flow being opposed by the resistance of the wire causes heating.
    Q = I2Rt, where Q is heat, I is current, R is resistance and t is time
    Guitar amps usually do heat up, because they run more power. While the coil does move and have airflow, it's not a primary mode of cooling. A smaller personal coil would heat up, but not significantly. The cheap chinese LM circuit would probably get fairly warm though.
  23. A formular doesn't quite live up to the complexity of a good amp design. The main difference reason for amps producing heat is based in the design (and types). Most Audio amps are one of the following classes: A: single ended output (rarely used for power output) B: push-pull configuration (most amps are this type) AB: a combination of both to reduce crossover distortion All of the above are not horribly efficient and can create quite some heat, they are still popular for their ability to produce great sound. D: pretty much a big PWM with a few filters. They are highly efficient and create very little heat. Not very popular amongst people who look for great accuracy in reproduction, but often used in battery powered products or high-power stage equipment. For this kind of thing , type D is certainly the best choice. Getting the magnetic fields from the wrist to the finger is another task. I'd recommend to place the coil as close to the magnet as somehow possible. If not, at least guide the field to the finger but don't waste it in free space.
  24. Aye. Also, the hotter your coil gets, the more resistance it'll have. One possible solution to the heat issue would be utilizing several weaker amps and an array of coils in different locations, oriented so that they constructively amplify the oscillations they induce in the magnet. Think of it like using batteries in parallel in a circuit(Batteries in parallel raise the Amperage(Current) in a circuit, as opposed to batteries in a series, which raise the Voltage). In a sense, if you increase the power sent to a single coil, you increase the range at the cost of intensity and increased heat. if you increase the force applied to the magnet, by using an array of coils, you increase the intensity of the magnet oscillation, at a given distance. 

     Using a single coil/amp system also increases the systems dependency on that point. But if you distribute the power across 3 or more amps, you have some inherent backups already incorporated into the system, without having to do anything fancy. 

    I haven't run any hard numbers, but based on an extremely oversimplified version of the formula describing magnetic field strength at a given "point"(forgive me if I butcher my terminology.), your field strength follows a pattern described by 1 over r cubed (1/(r^3)), where r is the "distance" from the "source" of the magnetic field.

  25. And that's the reason why you need to get as close to the magnet as possible. No array will fix your power demands when your distance is too big.
  26. But would an array up close reduce overall power consumption, since you'd be able to use smaller coils overall, thus reducing your resistance and necessary amp power?
  27. If you have an array you have to be careful the individual coils don't null out each others fields at some point. Power wise it's not much of a difference but I'd say it is easier to construct one suited coil instead of using multiple ones. If you can design your coil in a way to get 2mm closer to the magnet, go that way instead of throwing multiple coils in.
  28. Is copper wire expensive, or am I thick?
  29. A 50m spool of magnet wire was about $10 last time I bought some. I wouldn't recommend making your own coils though, it's boring, takes forever, and is never as good as a cheap aliexpress one from china.
  30. It depends on what kind of copper wire, but as a rule, when it comes to copper, it's expensive. There's a reason people rip copper piping off of air conditioners and sell it.

    I second that, but I find it calming to wind my own coils. 
Displaying comments 1 - 30 of 47