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Body Hacking: Thoughts Regarding My Magnet Implant (iamdann.com)
301 points by iamdann on Mar 21, 2012 | hide | past | favorite | 138 comments

Body modification? Pacemaker here.

Every six months I have to go in for a tuneup, a wireless data dump & service testing. Having having one's heart slowed to sub-40bpm via a few taps on a screen is...odd. Printed report tells assorted stories of daily activity periods, odd events, heart rate hitting programmed thresholds, etc. There have been some confluence of proximity & programming causing twitching under some circumstances (couldn't sleep on my left side for a year due to a lead pressing on & convulsing diaphragm) which were fixed completely thru software settings. Have a minimum threshold programmed in, and if it's set too high (say, 60bpm) and I relax deeply can feel it kicking in with "go faster!"

Proved quite useful a couple weeks back. Suffered a random onset of aortic flutter (can happen to anyone, just sorta happens), where a natural short-circuit in the beat-signal nerves sent the heart rate up to 349bpm (neatly documented on the printed data dump). For most people, this means a very scary and tense race to the emergency room, with AED paddles & drugs to bring it down until the problem can be surgically eliminated. My pacemaker hit the brakes at 150bpm, leaving me functional to wander in to the ER at my convenience; there, a tech was brought in to set up a more aggressive flutter-control program (70-100bpm more aware of actual physical needs). That kept things manageable until the drive-thru heart surgery to fix the problem (1 hour to send a probe up a vein to find & burn out the short, 3 hours rest, then discharged). Wasn't what the pacer was installed to handle (ventricular resynchronization), but the "while we're installing this, let's add a wire and program in some other someday-useful stuff" has indeed proven useful.

Other body modification is a mechanical heart valve. I tick. I've been confused with clocks.

Yes, MRIs are completely out of the question now. Work near a small one and get nervous walking by the door.

OK, so these weren't exactly voluntary. Choice aside, being a cyborg does make for interesting experiences & conversations.

ETA: BTW, not looking forward to replacing the battery. At least the device has been saying the battery will last another four years - for the last four years.

That's a fascinating read.

This kind of control and capability makes me wonder if they won't someday become common in a preventative/health monitoring role instead of only for cardiac defects. The risk during installation and problems with MRI seem pretty serious, so I doubt it could happen soon, but it's not impossible.

I wonder what some sort of self-assembing/modular device that can be fed in chunks through a vein catheter or keyhole surgery, and built in-situ could be plausible.

Not sure what to do about the MRI issue though. They're only going to get more common as we figure out superconductors, and they have none of the radiation downsides of CT. Maybe non-metallic construction, or perhaps when milli-Tesla MRI becomes a reasonable alternative?

Is the battery in yours single use, or recharged via induction loop?

Pacemaker installation is now an arthroscopic outpatient process. (Mine was in conjunction with open-heart valve replacement - not so much an outpatient process, but they're starting to do 'em that way too now.)

Battery is single-use. I wouldn't want a rechargeable, because that would require far more frequent charging - to wit, much more room for error. Missing a charge would mean a dead...me. I'll take the ~5-8 year hard-way replacement.

Pity they don't use nukes anymore; they worked great, until people started cremating them.

According to http://www.orau.org/ptp/collection/Miscellaneous/pacemaker.h... they're titanium cased and designed to withstand cremation, although I have no idea if that's true in practice.

What surprised me was that the total expected exposure was much higher for the patients spouse that the patient themselves. It's got twice the thickness of partner in which to be absorbed, but there's only close exposure for maybe 8-10 hours a day, and the inverse square to deal with.

Maybe some were. I'm basing it off a comment from a professor regarding nuclear power in small electronics. Quote (from memory, thus unreliable) below:

"So, they tested these things for all the possible stresses they would encounter -- high G maneuver and impact if they were in a car wreck, crushing force, electrical damage (from a lightening strike, etc), anything that they were likely to encounter whilst inside a human body. However, they were never thermally tested -- after all, why would the human body ever experience >1000 degrees F?

Ends up the answer is cremation. So, for a while, a major hazard around funeral homes was radioactive crematoriums."


Also apparently a mercury hazard.

"The whole body exposure is estimated to be approximately 0.1 rem per year to the patient and approximately 7.5 mrem per year to the patient's spouse." In the same units, 100mrem (patient) to 7.5mrem (spouse). Using the xkcd[1] radiation chart, that's the equivalent of a head CT scan every two years for the patient, and 2 plane flights a year for the partner.

1. http://xkcd.com/radiation/

Argh, I've looked at that page several times, and each time I've managed to misread a 'm' on that 0.1 rem figure.

Thanks for clearing it up!

Before we start using them in those roles (and massively expand "install base"), we're going to have to solve the security issues http://www.schneier.com/blog/archives/2008/03/hacking_medica....

Apologies in advance for not actually commenting on body hacking, but did you serve in the military? I'm trying to decide whether the writing style where you omit subjects and occasionally verbs comes from the military only, or whether it's more pervasive.

Nope, no military service. I do make a point of refining my writing style, with an underlying avoidance of repeating words leading to a reliance on implied words. Comes in part from frequent blogging, where reader attention spans are short and criticism for imperfection & incompleteness abound - to wit, high density content pays off. I've also always been of few words, to the point where one friend dubbed me "Noun Verb" because I tended to talk that way. My software is similar, concentrating on terse clarity, heavy on references and semantic implications. I'll spend a lot of time minimizing what's published, be it English or C++. Music of Philip Glass & other minimalists was rather influential and formative.

Upshot: it's just me.

I know this is getting really tangential, but prolongued exposure to the Japanese language (where they usually drop the leading I/he/she/we on a sentence) has made me start doing this myself fairly often in written communication, ala "sounds good, arriving soon."

I must admit, I rarely read comments the length of your original one (in a rush / short attention span; like you said). Once I started reading the first few lines, however, I found myself unable to stop and I ended up reading the whole thing.

So, I guess it works.

About that wireless connection to the device connected to your heart, and such things as security and bugs, here's a really excellent talk by Karen Sandler. https://www.youtube.com/watch?v=5XDTQLa3NjE

Having having one's heart slowed to sub-40bpm via a few taps on a screen is...odd.

Could you describe in detail what that experience was like? That's incredible.

Imagine being dropped from a great height with no sense of acceleration, just a sense of "oh my" brought on by rising innards.

One tech told more about the test. They really want to just shut the pacer off to see what the heart does without it. Problem is, a lot of people fall into a deep depression for several days. Even with it still beating, albeit slow, I felt rather...off...for the rest of the day.

Presumably a period of faster-than-normal beating would be similar to being dosed with adrenaline? It's intriguing how blood flow rates affect mood.

Really fascinating. Thanks for sharing!

Thanks for that it was really a much better story than a magnetic implant which comes off as silly to me.

If you ever write up more I sure would be interested.

It's a cool idea, but let's not give short shrift to the MRI downside. MRIs are a big deal in today's medical world. Not being able to get one, depending on circumstances, can present anything from a mild inconvenience to a significant challenge. Especially if it's because of some piece of metal you elected to have implanted.

I type these words with a (non-elective) series of metal prostheses implanted in my hand and wrist. Luckily, I don't set off metal detectors unless they're turned to extremely high sensitivities. But MRIs are out. I don't want to get into TMI detail, but let's just say that I have an ongoing medical condition that makes the inability to get MRIs a big setback.

Tread carefully with this stuff. Look before you leap.

There's a reason I have a Rod of Asclepius and "DO NOT MRI" tattooed on my wrist. Apparently it's quite possible to go through an MRI with implant intact, so long as the techs know about it. The inventor of these implants' advice about MRIs can be found here: http://www.stevehaworth.com/wordpress/index.php/welcome-from...

That is good to know. Thank you for the clarification. I'm glad the inventor took this into consideration.

> There's a reason I have a Rod of Asclepius and "DO NOT MRI" tattooed on my wrist.

You realize there are other large magnets in the world besides those for MRIs?

What do you have in mind? I can only come up with particle accelerators, nuclear fusion reactors and special cranes on junkyards..

High voltage transformers, demagnetizers (used in workshops all over the place), and large electric motors all come to mind.

You can feel transformers from a (comparatively) massive distance away: I can feel a 230-to-12V transformer from 5 to 10cm, which is generally bigger than the transformer is. So you'd know to steer clear. I mean, IAmDann said here, http://www.reddit.com/r/IAmA/comments/g7lom/iama_24_year_old... that he can feel subway power transformers while walking down the street.

Demagnetizers... isn't the whole point to enclose the field? I'd also expect a warning sign or two, or for you to pay attention and know it's there. This is one of those "make your decision, and then live with it" things, and part of "living with it" is being aware of these things (and that acquaintances with more humour than sense might try to hand you magnets you can lift tables with).

Large electric motors... Dunno, have no experience of them yet.

Do you get a sensation from switching power supplies vs transformers? Or is the frequency in a switching power supply too high to sense? (I've been studying power supplies a lot lately, so I'm curious.)

Tangentially on the topic of MRI safety, there's a fascinating story of a police officer who got too close to an MRI. The magnet yanked the gun out of his hand and the gun went off despite the thumb safety being engaged. (Nobody was hurt and the MRI received only superficial damage.) Apparently the strong magnetic field pulled the firing pin block out of the way, allowing the gun to go off. Details: http://www.ajronline.org/content/178/5/1092.full

Thinkpad switch-mode power supplies give almost no sensation, but I have gotten a distinct (and pretty distinctive) "buzz" from a Dell power supply. I'll point out others seem to be much more sensitive than I, as well (see jaa's comment, below; he can feel power cables. I can't). So the answer is... it depends? ",)

I once broke my finger handling magnets from a really old hard drive. I don't want to think about what would have happened if I had magnets implanted in my fingers.

They're rarely as strong as MRI magnets. My sister, who works as MRI technician, have seen MRI pulling with a blazing speed whole wheelchairs or heavy steel oxygen canisters from many meters away.

Yes, but how many large magnetic fields does one gets stuck into while unconscious that _aren't_ MRIs?

Besides, I've been exposed to serious magnets; the inverse cube law is my friend. Plus, even when I did come close to a strong magnet, all that happened was my implant flipped ends. In my finger, yes, but it wasn't painful (my implant is a cylinder, about as tall as it is wide; a disc magnet would have been much worse).

> Yes, but how many large magnetic fields does one gets stuck into while unconscious that _aren't_ MRIs?

If by "unconscious" you mean asleep, not many.

If by "unconscious" you mean unaware, plenty. Try walking past these in a lab:


FYI: Neodymium magnet strength is of order 1T, same as MRI.

See where I mentioned the implant "rolling over"? That was caused by someone waving a stack of over 20 of these type of neodyms (http://www.magnets2buy.com/acatalog/neodymium-discs.html) within an inch of my finger. Those are so powerful that splitting a stack of 8 and letting them re-attract rejoins the stack with such force it smashes the magnets that make contact. So while I'm sure coming close to one of those would _hurt_, I don't think I'd either end up stuck to the magnet or having the implant dragged out of me.

The implant is powerful for its size, but its size is _tiny_ (half a grain of rice is a good comparison). It's not going to be as strongly attracted as that.

I'd like to contact you regarding how you went about getting your implant. My email is in my profile.

The emails in profiles are not visible to other users. This is a UI issue here that's bitten everyone.

Well now, isn't that something I should have checked. Capitalist.Carter@gmail.com

I'm sure it is, but apparently I can't see it, through either incompetence or measly karma. The short-form of my implant tale is here: http://discuss.biohack.me/discussion/comment/862#Comment_862

I have a magnet implant and looked into this. I found a study about MRIs and cochlear implants and not once did the study mention any dangers. Instead their concerns were based on demagnetizing the implant, and they found that the risk of demagnetization could be mitigated by aligning the patient in a certain way.

I know that cochlear implants are very different from finger magnets (cochlear implants are attached to bone) but it does challenge some of my basic assumptions.

It should also be noted that it would take less than five minutes to remove the implant with a scalpel.

A bit OT, but does it depend on the metal used? My wife's wrist was reconstructed using a set of metal plates after it was shattered a few years ago. However, she's had at least three MRIs (for an unrelated problem) since then. The plates may be titanium and not surgical steel, so perhaps that's the difference?

That's correct. Titanium is widely used for implants and is non-ferromagnetic so you can safely be MRI'ed with a titanium implant.

Isn't there inductive heating? It's conductive.

Yes, non ferromagnetic materials are still subject to some inductive heating due to eddy currents* but I have no feeling for how much.

*I've had the pleasure of being MRI'd a few times in a 4 Tesla research MRI (normal MRI's operate around 1.5T) and occasionally I would get nerve stimulation due to eddy currents set up in tissue. An interesting feeling!

Could be. I'm in a similar situation as your wife -- wrist and partial hand reconstruction -- but I'm under strict guidance to avoid MRIs, and have to report as such at hospitals and doctors' offices. I've also got a metal fixture in one of my toes on my left foot -- but, for whatever reason, that one's never caused an issue. Pretty sure the toe plate is titanium, and the assorted hardware in my wrist and hand are not.

Though it would seem that removing the magnet wouldn't be too much of a problem. I mean, it should show up under flouroscopy, and failing that, I guess you could mark the spot with tattoos with when get them implanted.

Would still be a headache though.

If you'd like a lower effort version: I glued a tiny, but powerful, magnet to my fingernail and then coated it with a few layers of nail polish.

It looked more than a little flashy, and it provided less sensation than it would've implanted, but it worked surprisingly well.

What kind of glue did you use? I'd love to try the concept, but as a physicist I can't afford to be permanently magnetic.

Couldn't you simply carry a magnetic ring? Or would that not work for some reason?

Where's a good place to get magnetic rings for this purpose? I searched Amazon and found things like magnetic bracelets marketed as alternative medicine to cure you. None of the reviews I found mentioned using them as an electromagnetic sensor, so I can't tell if they're useful for the purpose.

I found a friend who's had magnet rings; he pointed me to some info: http://hackaday.com/2012/01/02/give-yourself-a-sixth-sense-o... (follow the links; it links to "Holy Scrap" blog which links to a couple online magnetic-ring-sellers).

I also found a ring sizing guide: http://pages.ebay.com/buy/guides/ring-sizing-guide/

There should be a difference in sensation because of the difference in mass of the ring versus implant. An implant, simply because it is so much smaller, should have a stronger reaction, should move or vibrate more, for a given strength of field.

Why not just have a magnet finger ring?

How long did it stay on?

Fascinating article. Speaking as someone who as worked around MRIs, I think the author underestimates the risk of being put in an MRI machine. It would be worth carrying a wallet card or wrist band noting that he has an implant (though emergency MRIs are relatively uncommon).

It's also worth noting that the fascial compartments of the hand can make infections tough to treat, and compartment syndrome can occasionally lead to serious problems requiring finger amputations.

Regardless, it's an interesting experiment that I'm glad someone who wasn't me performed.

Last I checked the MRI risk seemed low due to it's placement, shape, and the minimal strength of the magnet. Do you have any specific concerns?

PS: What if I need an MRI?

Originally it was thought that the magnets would always rip out of the skin and attach themselves to the MRI. However, we now know of a few people who have the magnets have gone through MRIs and this did not happen. One person reported that the magnet just vibrated very strongly. Another person reported that the techs shielded his hand, as they would with someone who had shrapnel or other implants. However, there are several different types of MRIs, so we can make no guarantee of what will happen during your MRI, so you must discuss it with the technician. It is likely that they will give you a hard time about it, so you should be prepared for this and for any possible risks to yourself. It’s also possible that the MRI might demagnetize your magnet.


Obviously I have no first-hand experience with implanted magnets, but MRI magnets are generally getting stronger. What is safe for a 1.5 tesla MRI may not hold for a 3-4 tesla MRI. The rapid magnetic oscillation has been known to heat up wires and cause burns.

There's some people horsing around with 4T MRI that might give you pause.


Thanks for that, I suspect infection is still probably a more serious risk overall, but a 4+T MRI does give me pause.

PS: Then again at 10T you get to fly so it may still be worth the risk. http://www.youtube.com/watch?v=A1vyB-O5i6E ;-)

On the other hand, there are developments in increasing MRI sensitivity that allow them to be effective with weaker magnetic fields. Weaker magnetic fields means less power, less cooling, lower cost, and more widely available.

I don't know that I would want an implant, but I'd like to try a haptic compass. You strap it on and it gives you a physical sensation of where north is, as if you were a bird with magnetoception.

Wire article on haptic compasses: http://www.wired.com/wired/archive/15.04/esp.html

The funny thing about these is that they don't really make you constantly aware of where north is. To answer that question you would have to concentrate on the vibration. What acutally happens is way cooler: You become subconsciously aware of the structure of the space surrounding you. This is something that everyone has to a leser extent i.e. you could point at the direction of various objects around you and tell me roughly how far away they are even without looking. When you have been wearing the belt for a few weeks you are able to do this even for objects that are not in you immediate vicinity. You get an actual feeling for the location of all kinds of things. Imagine having an accurate intuition for the location of your home town or the next highway exit! Another example: you could visit a city where you have never been before, wander around the streets without caring for where you go and then immediately find the shortest route back to where you started. And it would be about as hard for you as finding the way to the door of the room you're in right now.

Sounds neat. I just use my phone.

You say that as if it's just as convenient to get out your phone and get your map up as it is to just intuitively know where to go.

That would be nice, and I imagine I could get used to the noise. Problem is, others wouldn't. Vibration has this effect in cellphones, you can hear the rumble and it could disturb classmates or coworkers.

It would be cool to have something like this that defaults to north, but could be programmed using GPS and a smartphone to point somewhere else.

> It would be cool to have something like this that defaults to north, but could be programmed using GPS and a smartphone to point somewhere else.

Absolutely, bike rides to unknown places would be a joy.

I hope technology such as this can help make the world of body modification a little more palatable to average folk.

The vast majority of people go only as far as some piercings and maybe a tattoo. We need to get away from the absurdity of contemporary body mod culture: tooth sharpening, scarification, branding, horn implants, sclera tattoos, gauging, suspension, tongue bifurcation, lip discs, genital modifications…it’s too much.

That kind of modification is a dead-end because it doesn’t fulfill its nominally transhumanist goals. But regular people could warm up to things like magnets and RFID tags, or, say, internal sensors to let you know of impending health problems. That sort of body modification provides actual value in the form of information that would otherwise be unavailable or inconvenient to obtain. I think that’s where we’re headed in the next couple of decades.

> We need to get away from the absurdity of contemporary body mod culture: tooth sharpening, scarification, branding, horn implants, sclera tattoos, gauging, suspension, tongue bifurcation, lip discs, genital modifications…it’s too much.

... why?

> That kind of modification is a dead-end because it doesn’t fulfill its nominally transhumanist goals.

Does art have to?

No, as an art form it’s great! But there are also plenty of mods that serve practical purposes. People who are put off by the artistic culture won’t see the benefits of other mods. For their sake, we should show that there is another side.

Oh, I see. I didn't read that in your earlier post. Yes, I could see the benefit; though I can understand why people would be very concerned about a few of these, especially the RFIDs, for religious reasons (Mark of the Beast)

> I also figure that if I’m ever incapacitated and put in an MRI machine without the ability to give the doctor any forewarning, a tiny magnet getting ripped out of my finger will be the least of my concerns.

It might be a rather bigger concern for the owner of the MRI though...

> It might be a rather bigger concern for the owner of the MRI though...

Not to mention all the other patients who need the MRI machine your "sixth sense" just shot a hole through.

The thing is half the size of a grain of rice, and isn't such a strong magnet. I don't think it's gonna cause major damage. Wheelchairs or oxygen tanks cause damage. Quarters and dimes are just annoying and need to be fished out.

(This my recollection from my friends who've done research with MRIs. I have no first-hand experience with them except once as a patient.)

Or any body parts that might be in the way between the pinky and the MRI machine.

Won't they get some metal detector over your first? Who knows you might just, let's say, have a magnet in your little finger! But seriously, there are more metal things under your skin possible, so if you can't make them 100% sure nothing is going to happen when they turn it on, I guess they will find out by themselves beforehand.

My dad's a radiologist and I've never seen anyone get metal detected prior to an MRI. Maybe they have one for unconscious ER patients, but I've never heard of it.

I've had two tiny disc magnet implants in two fingers for over three years now. I originally had it implanted as part of an idea for a novel man-machine interface I came up with for my Master's degree research project at the Uni of Reading (UK).

The early reports of electrical fields inducing sensations had intrigued me, so I set out to explore the possibility of controlling the magnet with an external electromagnet, which in my final design was a simple coil ring worn around the finger, and use it as a sensory substitution man-machine interface. After measuring the frequency response, sensitivity etc characteristics, I finally put it into a practical application demo by using the interface to couple an ultrasonic ranger and a mobile phone to myself. The ultrasonic ranger was used to feed the distance information and I learnt pretty quickly to judge distances and move about with my eyes closed. In the phone scenario, I encoded characters as Morse Code pulses and could "read" the incoming text messages. My morse skills weren't that good but it worked!

The internalization of the sensory information, with the magnet being inside the body, made a qualitative subjective difference as opposed to simply having a magnet glued to the finger.

There's a bit of info on this and pictures/xrays on my blog: http://www.jawish.org/blog/plugin/tag/smii. The details on the interface is on the paper we published: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5898...

My best experience with real world magnetic fields? Wires. It was mind blowing to be able to feel the field around a wire which we usually think nothing of. The power cable to the electric heater generated a field I could "touch" about 4-5 inches away! What does touching it feel like? Like touching a stream of air. :)

I've read that paper, and I'd like to say thanks; being able to point at graphs that say I'm not imagining the sensation from my implant has occasionally been helpful. ",)

> While a magnet implant doesn’t technically count as a “sixth sense” (it’s more of an extension of our existing sense of touch), the way that the body internalizes these tiny magnetic vibrations feels truly foreign.

Let's just start by dispelling the myth that there are "five senses", and then we can agree that this does provide an additional sense. The inner ear is an orientation sensor and orientation is clearly a sense, therefore there are more than "five senses".

This is one of those things that people "know" but don't actually care enough to take action on. "The five senses" is easy to teach in school and has become a turn of phrase meaning "the things we can perceive".

Classifying senses is difficult. Some believe we have six, some believe we have many, some believe different people may have different senses. Some senses that I've read simply described one of the "five" senses being perceived in a slightly different way (the sense of pain is the sense of touch), some extra senses are simply two or more of the "five" senses put together (such as being able to sense when there's someone else in the room).

I'm not a neuroscientist, so I'll just leave it at saying "five senses" is easy to understand and explain for a complex subject that every common man needs to understand. Trying to complicate it further will garner no fruit.

Are you seriously arguing that ignorance is a good thing because of what "some believe" and "complexity"? You could just as well be making the case for creationism.

I'm arguing that there are things people need to be aware of but don't necessarily need to know the intimate details of. I know how my car's engine works and I know how to find out what broke when something went wrong, but I don't know (and don't need to know) how to tear down and replace any broken part. For that I take it to my mechanic. He knows how to rebuild an engine, but doesn't know how to set up and run his website. That's where my specialty lies. This isn't ignorance, it's accepting that you can't be an expert at everything. Every bit of information you learn comes with an opportunity cost attached.

The difference between neuroscience and my engine is, people know how the engine was built because someone actually built it. In neuroscience, even the experts don't know how everything works, and it's a matter of much debate. Do you think we should teach this debate to every student in our schools, knowing that the kids aren't going to keep current with that debate as they age and will be running on misinformation the rest of their lives? Or should we teach them what they need to know then give them the tools to learn more as they gain interest in the subject?

Let's teach scientific facts in schools. To quote Wikipedia,

What constitutes a sense is a matter of some debate, leading to difficulties in defining what exactly a sense is.

After reading the wikipedia article, are you still arguing for teaching "the five senses"? Did I not satisfactorily dispel this notion?

When we learn the Bohr atomic model, teachers explain that it is not completely accurate, but a useful starter mental model. Teachers should explain that there are more than 5 senses as well.

I don't know how old you are or in what geographical location you grew up in, but in my elementary school in the Midwest US, we were taught about the five senses. It was left at that. In high school biology, we were taught that everything we learned in elementary was wrong, simplified so it could be taught to hold our attention (a difficult chore with children).

This is where my teacher told us that we had more senses. Sense of pain. Sense of balance. Sense of electricity. I accept that there are more things that can be called senses. I also accept that there may be reason to teach them. However, there are a lot of things taught in schools, and a lot of things that are not. The concept of sense is important to know, but so are a lot of things. My school taught that there may be more senses, so I guess I might be confused by the notion of any educated person not knowing other senses exist. As a simple teaching method (keeping in mind public schools are mandatory and therefor must keep the students attention), "five senses" as an example works for children, and as a turn of phrase for adults. It's up to the educated mind to continue learning, and this is where schools fail.

Teach fact. Teach how to find these facts. Only get into the detail when there is something to be gained. Anything else and you risk losing your student. Like I said originally, people "know" there are more than five senses. The phrase sticks because that's what we learn as a child.

Quick! Were you taught that protons exist? If you answered yes, you're wrong, but many people believe they do, and the real answer is complex, and protons are a "good enough" answer that the entirety of chemistry pays very little attention to anything deeper. So protons and neutrons are still taught, and getting into quarks properly quite often only happens in college-level courses.

Protons don't exist? O.o I thought they were a cluster of quarks with a positive charge O.o. Naming a set of objects as one unit isn't bad.

Were you taught we're made up of cells? If you answered yes, you're wrong, but many people believe they do, and the real answer is complex, and protons are a "good enough" answer blah blah. The reality is much more complicated, with mitochondria and nucleii, etc.

My physics-fu is lacking, but I was also taught that protons are made up of quarks. If a proton is really just a silly term for a collection of quarks then it's not lying, there's just a smaller thing when we break them apart.

I was trying (badly, I admit) to point out that letting possibly over-simplistic answers sit is not equivalent to promoting creationism. Freehunter does much better above.

"proprioception" is one name for the sense of spatial orientation.

Proprioception means you can sense the position of your limbs. That is different that what the inner ear provides. You can be blind, deaf, and paralyzed from the neck down, and you will still be able to know when the airplane is starting to descend, even though you will have lost all proprioception.

As someone who flys with pilots they will tell me "You may think the plane is descending but you don't know the plane is descending until the instruments confirm it" :-) One of the fun things they do is fly various patterns that give your inner ear signals that you are doing one thing when the plane is doing something else, its part of a ritual to always check your instruments.

Anyway the notion of extending sense is interesting, and I wonder if anyone has implanted a hall effect sensor (rather than a magnet) and had the eddy current run to the nerve nexus in a finger tip. You would not be able to pick up paper clips but you should be able to 'feel' all sorts of electro-magnetic phenomena.

Integrating with nerves is have-you-a-pet-surgeon territory, and pretty much all of this stuff is done by piercers, or insane amateurs with no respect for their own bodily integrity (see the amazing Lepht Anonym). Few doctors will touch this stuff, for liability or Hippocratic Oath reasons.

The only people I know who _have_ done it are Dr. and Mrs. Warwick, who used it to do nerve-firing-over-IP from New York to Reading.

And your inner ear is fooled because the gloop in the organ-I-can't-remember-the-name-of suffers from inertia, registering false movements (or false lack of movement). Which is why spinning around in a circle for a while makes you dizzy; your ear is registering the movement continuing, your visual cortex is seeing everything staying still, and your brain has no idea how to integrate the two. ",)

Great submission on that topic: http://news.ycombinator.com/item?id=3144099

I think OP means the vestibular system. Proprioception requires more than balance information, and it's more the sense of knowing where your body parts are relative to each other rather than orientation wrt the external world.

I have an rfid implant, but I haven't found any real uses for it. Of course I thought about what I was was going to do with it before I got the implant, and had some ideas and got the implant thinking that tinkering with applications would shine new light, but in the end it's quite lackluster to have one. It's also strange how exotic it seems to have one when you don't have it, and how pedestrian it feels when you actually have it.

I sort of read that same feeling between the lines of the article. It's a bit of a novelty when you first get it, but after a while it's not all that special.

Related: Nokia has some patent application for a magnetic tattoo and/or skin patch that would provide haptic feedback from a magnetic field projected by your phone: http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Se...

Not sure how they would shield from outside interference/have the field coming from your pocket reach your hand in all situations though.

There was a House episode where a prisoner had a low-quality tattoo containing too much iron (or something). The prisoner went into the MRI and the experience was excruciating.

Not sure if there's any grain of truth to that or not. It was Hollywood.

MythBusters covered this one in one of the earlier seasons. They couldn't produce any sort of effect even with unlikely high metal concentrations in the ink.

Metal fabricator of my acquaintance probably can't have an MRI, as he's got too many metal splinters floating around his body. So probably true, though I don't know about tattoos...

Here's Quinn Norton's talk at 23C3 (five years ago) about functional body modification, including her personal experience & some of the problems with embedded magnets: warning it's a little graphic https://www.youtube.com/watch?v=voA7Uz7uABE There's a text-and-picture summary here if you don't want to watch the video, also with graphic photos: http://www.we-make-money-not-art.com/archives/2007/01/quinn-...

I got mine only two weeks ago, and I'm looking forward to exploring that new "sense".

I was kinda surprised the most frequently asked question when ppl heard about it – and the one that came pretty unexpected for me – was "why?!".

thanks for the article!

I love meeting other people with the implant and doing a "magnet handshake" by brushing the fingers next to each other.

I have one too! I'm kind of surprised that there are not one, but two other people on HN with magnet implants.

And I too am really surprised when people ask "why?" Is it not obvious?

And I too am really surprised when people ask "why?" Is it not obvious?

No, actually, it isn't. Is it just because it's "cool" (like a piercing) or is it serving some practical purpose for you beyond that? Genuinely curious.

It augments your sense of touch. I suppose this isn't obvious (however it seems obvious to me that many people would want to augment their senses).

Does it serve a practical purpose for me? No, I have it because it's "cool" but not at all in the same way that piercings are "cool." It's cool because I can feel motors, power transformers, etc.

It's also very useful for picking up dropped paperclips.

Thanks, that makes a lot of sense.

Actually, it wasn't obvious to me at all. I incredulously began reading the article, assuming some kind of fraud medicinal claim.

I was very excited and interested to learn the actual purpose. Fascinating.

luckily a friend of mine has one too, so I've been able to do that already.

hope to meet more ppl with magnets soon – if you ever happen to be in Germany, drop me a line :).

Note: OnSwipe damaged site, and adding ?onswipe_ redirect=never goes into a redirect loop.

Thanks, I actually noticed that last night and forgot to deactivate it.

I've followed magnetic implants for a while, always considering getting my own, as well as an RFID implant. I'm also a fan of BMEZine and there can be quite a few overlaying interests in the two communities. Whiles its not as good as it used to be when Shannon (guy mentioned in OP's article) was editor, I suggest people subscribe if they're interested in such things.

Why not get a magnet ring? It's nondestructive and gives you access to many of the same sensations.

Nate (http://feelingwaves.blogspot.com/) recommends supergluing a small neodymium to your fingertip as the best model of how the implant actually feels; I haven't tried it, myself.

I have. I should repeat it with a stronger magnet. I just used one from the 'random magnets I've accumulated since I was a kid' pile and picked one primarily for the size, but it only allowed me to sense sizable motors. A simple band-aid was all the social camouflage it needed, which was nice.

I meant to compare with the sensation from my implant. (",)

It's also been tried with sticking tiny magnets to the fingernails, then varnishing on top: http://www.psfk.com/2010/06/fingernails-implanted-with-magne...

I just looked online, and all I could find were the "healing" variety sold by charlatans. Know of any places who sell them for people who have a basic understanding of scientific reasoning?

Super magnet man is your guy: http://www.supermagnetman.net/index.php?cPath=48

Is there some reason to get the ones with the axial field orientation vs the perpendicular orientation?

I've actually heard this suggestion a lot. For me, wearing a magnetic ring is completely different from having the implant.

For one, the sense would be centered around the base of your finger, which is naturally more stable and less sensitive. A magnetic ring worn where normal rings are worn would not give you much of a sensitivity at all.

Try feeling the shape of an object with your palm versus with the tip of your finger.

I design toys that use magnets.. I end up carving my own tools out of wood so I can epoxy them in proper places.

They are super annoying to make stay where you want them.. I would go crazy if I had one inside me.

Hah! I can imagine epoxy covered magnets sticking to my little finger.


The author reports that the sensations are different between a ring and an implant. I can’t speak to the differences firsthand, as I have no implant, but I gather that the perception of an external ring is more tool-like than sense-like.

Man, the last time I read about these was back during the original trials when it was still pretty finicky. Feeling seriously tempted now.

I never heard of this before, but I want one so bad right now. However, the MRI thing is a real deal-break for me... oh well :(

I found these quite interesting, but I'd never get one implanted: using small screwdrivers and wrenches would be a pain, it affects the phone's magnetometer and you have to be careful not to cut your finger or when lifting anything heavy (and using all your fingers' strength)...

The worst inconvenience I've had with mine is handling small change; 1, 2, and 5 Euro-cent coins stick to it. ",)

And I've done a little rock-climbing since I got mine. Not enough to be entirely sure with it, but some.

I've had no issues with screwdrivers or wrenches, it doesn't affect my iPhone at all (I've brushed that finger over every inch of that device trying to feel inside it) and it was surprisingly easy to adjust the way I carry heavy things.

Hmm, well that's pretty good, then...

I thought something that was cooler (and less permanent) was the feelspace belt: it has a compass module and a bunch of of vibrating motors, so you can always 'feel' magnetic north


Looks like a pretty simple device. Now, when can we start seeing more improvements (particularly use/assembly related) on open source EEGs? I'm far more interested in monitoring my brain activity outside of my psychologist's office. Odd signal activity and all that...

I was thinking about getting this done, but then I realized that recently I've been doing so much metal machining work, that the concept of picking up metal filings constantly with my finger just sounds painful.

Contacted Steve Haworth today to arrange an appointment to get one implanted. Been wanting one for a few years now, this article tipped the scales.

Is this magnet powerful enough to damage magnetic media (HDDs, Tapes, etc)?

It's actually surprisingly hard to intentionally damage most magnetic media (except audio tape and really cheap magstripe cards and you probably aren't going to see either today) with permanent magnet, so one can safely assume, that this is not a problem.

from TFA:

> Luckily, the magnet is not strong enough to wipe out credit cards nor will it negatively affect electronics or computer monitors.

> Luckily, the magnet is not strong enough to wipe out credit cards nor will it negatively affect electronics or computer monitors.

He doesn't specifically say anything about tapes or Hard Drives, but I doubt it.

I've tried, and from my experiments it has not been strong enough to destroy anything.

what happens if you actually operate one of those cloth retail super magnets de-taggers? does your hand get pulled away or inside it?

Obligatory: Magneto

1. Not obligatory 2. He's not using the magnet to generate AC electricity 3. If he were to face comic character Magneto, it would be much like the MRI case 4. If you're asserting he is Magneto, he has no ability to shape, or even move metal at a distance.

Can you explain what you were trying to say using more than two words? I really don't follow what you're trying to get at. Both words seem meaningless and wrong in this context.

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