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Medicine Science

Bionic Implants and Spectrum Clash 98

Posted by samzenpus
from the feel-the-waves dept.
angry tapir writes "The battle over scarce radio spectrum that has embroiled the mobile broadband world even extends to a little-known type of wireless network that promises to reconnect the human nervous system with paralyzed limbs. At its monthly meeting next week, the U.S. Federal Communications Commission will consider whether four sets of frequencies between 413MHz and 457MHz can be used by networks of sensors implanted in patients who suffer from various forms of paralysis. One intended purpose of these MMNS (medical micropower network systems) is to transmit movement commands from a sensor on a patient's spinal cord, through a wearable MCU (master control unit), to implants that electrically stimulate nerves."
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Bionic Implants and Spectrum Clash

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  • Hmm... (Score:5, Funny)

    by girlintraining (1395911) on Wednesday November 23, 2011 @07:27PM (#38154286)
    Part 16 just got a lot more interesting. Devices must accept harmful interference, including interference which may cause undesired operation. Sound familiar? So if your prosthetic arm starts punching you repeatedly in the face until you're dead, ah well... these things happen!
    • by Nethead (1563)

      Part 15, maybe?

      Part 90 (Land/Mobile) and Part 97 (Amateur) have a lot of medium to high power transmitters in that range.

      • Re: (Score:2, Funny)

        by Anonymous Coward

        Part 69 governs radio controlled penile implants, vibrators and all electronic sex toys.

      • by laing (303349)
        Yep. The 70cm amateur radio spectrum sits right in the middle of that range. It's widely used and will not be surrendered without a fight. Why not instead use some of the frequency spectrum recently freed up by the analog television broadcast transmitters for this purpose?
        • by Nethead (1563)

          ..will not be surrendered without a fight.

          Seconday use by hams. Primary by US Government. And "Above Line-A" it's not even available for hams, or near various Air Force installations.

          The ARRL might bitch a bit if 433MHz is taken away, but hams, generally being law and FCC regulation abiding folks, will follow the band plan.
           

      • by AmiMoJo (196126)

        433MHz is popular with industry. The product I am working on at the moment uses 433MHz to transmit data about leaks in water pipes. During the day it makes one transmission every five seconds, and there will be hundreds of these things deployed in a town or city.

        Considering the interference problems we have in some areas I'd prefer by bionic arm to use a dedicated frequency at very low power.

    • Re:Hmm... (Score:5, Interesting)

      by theshowmecanuck (703852) on Wednesday November 23, 2011 @08:42PM (#38154730) Journal
      I was thinking about the villains in old western movies who would shoot their 'six guns' at someone's feet and tell them to dance. Hackers could take this to a whole new level.
    • by c6gunner (950153)

      On the other hand, next time you get caught masturbating in public, you've got a pretty sweet excuse ...

  • suddenly visions of light cycles and disc wars came to mind....

  • I hope they're using a packet based protocol with massive error correction.

    • by jd (1658) <<moc.oohay> <ta> <kapimi>> on Wednesday November 23, 2011 @07:55PM (#38154506) Homepage Journal

      Reed-Solomon can correct bit errors, Turbo Codes can correct block errors, and if you also include a cryptographic hash of the packet you can determine if the corrections fixed the data or it is still corrupt. Depending on the bandwidth consumed by the actual data, you might be able to throw in a lot of error correction bits and even have the error correction checksummed and error-corrected.

      • by fatboy (6851)

        I see your "Reed-Solomon" and "Turbo Codes" and raise you with "Front-end Overload". :)

        • by jd (1658)

          Yeah. Random clicks (reed-solomon) or bursty noise (turbo codes) are solvable provided they don't swamp the error correction bits. Front-end overload can't be solved by this solution at all. (See my alternative of running fibre.) I gracefully concede this hand, and pay up the 1024 virtual beers.

      • by Samantha Wright (1324923) on Wednesday November 23, 2011 @08:31PM (#38154678) Homepage Journal
        Why not go the whole way and encrypt the whole signal? Then you'd have to handshake with your hands every morning.
        • by nzac (1822298)

          Not that it would effect the GP solution (which is overkill at that range) but encryption would the problem more difficult and certainly does not solve it. You now need to communicate uniformly distributed data perfectly which is much more difficult.

          To stop other people intentionally interfering with your device is where encryption/cryptography would be useful.

      • by nzac (1822298)

        You sound like you learned that in Masters or Summer research but have never used them, apologies if not.

        Not that my education is any higher but at that range and considering other power requirements increasing transmission power would be the easiest way as transmission failure could be almost as bad as mis - communication. At that range you can ramp up the power for whatever band-with you need i guess though.

        For some implants you would also want to favor the MSB as errors on the smaller ones may be ok.

        Cha

        • by jd (1658)

          Paul Shannon showed increasing power does bugger all for you in the end. I learned it whilst developing military communications systems.

          • by nzac (1822298)

            learned it whilst developing military communications systems.

            There are so many ways that could be less impressive than it sounds if you don't deny my first line. Yes i did judge you on the existence and contents of your Journal.

            Paul Shannon showed increasing power does bugger all for you in the end.

            He showed its horribly inefficient but there a 1.5 m range these don't suffer too much from inverse square. He also showed that if you don't have more power than the interference you are fucked.

      • So Reed-Solomon is a random error correcting code and turbo codes are burst error correcting codes? That's a very misleading claim. In the past RS was often used to be used as the outer of two concatenated codes for its burst error correction capability.

        Cranking up the redundancy or using a huge interleaver may be fine when a couple seconds of latency isn't a big problem (deep space communications, compact discs, etc.) but there's simply no good way to correct long bursts or errors in latency constrained

        • by jd (1658)

          A lot of error-correcting codes can be parallelized. Not brilliantly, but certainly adequately. You've also got to bear in mind that if you're going with a bionic implant (which isn't a cheap thing, and where space and weight constraints are often high) you're probably going to be going with ASICs with heavy-duty digital signal processing for almost everything. In fact, highly special-purpose parts should be everything. There shouldn't be any general-purpose computing devices, no software and even analogue

          • That has nothing to do with your original claim regarding RS codes and turbo codes, not does it address the main problem with your implication that bursts of errors are easily correctable. They aren't when the burst length is on the same order as the tolerable amount of latency, and all the processing power in the world does nothing to change that.
            • by jd (1658)

              Already answered that elsewhere in this block of replies. If you're going to harangue, at least read what you're haranguing about.

              • Harangue? Lol, get a grip. You didn't answer anything. I was being polite, but I could tell from the first post that you're a person who blurts out every loosely grasped buzzword they've heard in order to come across as knowledgeable.
                • by jd (1658)

                  You're not capable of politeness. Hell, I'm not sure what you ARE capable of. I can tell you now I'd have failed you in any class I taught for selectively picking up one post rather than the context of my posts. You "could tell"? Indeed? I'm impressed that you could "tell" from a single snippet of a minute fraction of a conversation not only the entire content of that discussion but the capabilities of everyone within it. So very impressed. Perhaps you could tell me my IQ, height and favourite tea whilst yo

      • But then who will error correct and checksum the error correction and checksum of the error correction and checksum of the original data?

        • by jd (1658)

          The probability of an error being such that the error correction will adjust the data and the cryptographic hash in ways such that the hash matches the data is negligible. (A trivial checksum like CRC32 would likely work just fine most of the time, but with medical implants you want to reduce the odds of mangled data as far as humanly possible. One in a million is still far too frequent. Whirlpool or one of the SHA3 candidates would seem better.)

          So long as data is oversampled and then filtered as needed at

  • by Anonymous Coward

    What prevents a multi-frequency technology like spread spectrum from reliably taking advantage of this, and a wider range of other frequencies?

  • by BenJCarter (902199) on Wednesday November 23, 2011 @07:45PM (#38154428)
    The fact that wireless signals might move the body randomly (or worse), seems dangerous. What about conductive tattoos instead?
    • by jd (1658) <<moc.oohay> <ta> <kapimi>> on Wednesday November 23, 2011 @08:03PM (#38154568) Homepage Journal

      Optic fibre seems the way to go. Carries the maximum amount of data and is the least prone to interference. It is also already used by some sea sponges instead of regular nerves, so it is a known biological solution. You can convert the optics into electrical impulses in the bionic implant and vice versa. If you went this route, then future iterations could involve unthreading dead nerves from the spinal cord and running the fibre down it. Increased protection from damage and increased compatibility with how the body works.

      • Fiber cable would also provide WAY more bandwidth. That being said, it would be far more invasive to install than a thin tattoo line. If it was me, I'd rather get the tat provided it functioned adequately.
        • by jd (1658)

          Bandwidth is actually a big reason for this line of thinking for me. An actual limb has an enormous number of nerve endings to senses, muscles, etc. One of the problems with current handling of amputees is that most of the nerves body-side are allowed to drift, creating illusory ("phantom") sensations. Optics can certainly carry the density of information needed to supply every residual nerve with valid input. Artificial limbs can't generate that much data now, so you'd lock most of the values to ground, bu

          • Nerves communicate via electrons. Light would have to be tranceived into electrons at each end...
            • by jd (1658)

              Yes. The multiplexer would need to be a chip that took analogue inputs (which is fine, mixed signals is old tech), run them through ADCs and emit via a semiconductor laser. You'd need a similar device that did the reverse. But because the multiplexer/demultiplexer are unidirectional and some nerves are bidirectional (not a vast number), you would need to make sure that only one circuit was active at a time. Which is actually good - you can then put them onto the same die because there's no possibility of an

      • by skids (119237)

        Not sure bandwidth is a limitation in this application. We're talking a few analogue values with a relatively low time resolution (based on normal human reflex times.).

        That said, I don't even want RF in my car (other than the door locks). Forget my body, so bring on the fiber. Or for that matter, just throw that light straight through the tissue without a waveguide. At least that way as long as I'm clothed there won't be much interference.

        • by jd (1658)

          I have no idea how many nerves run down the spinal column, but I think it's safe to say that you could replace most/all of the parts of the nerve in the spine with a single optic fibre in dense multiplexing mode, with some variant of packet switches to identify if a given packet is supposed to be for a given nerve ending and then convert the payload into the correct voltage. The bandwidth would therefore allow you to have as complex a virtual nervous system as you like. That would be the only benefit of hav

      • Dunno about the durabilty of optical. The frequent twisting and flexing of optical might cause it to fail soon. I haven't handled high quality fiber so that may be no problem.
        Biology builds things in a completely different way. The sea sponges build the fiber up atom by atom. This gives great flexibility in "design". The sea sponge may be able to repair it's optical fibers when damaged. We puny humans are currently not able to repair minor damages on an optical fiber without cutting the fiber out first.
        • by jd (1658)

          Yes, that is a potential problem. I don't know the answer to that and it may well be that the resilience of current optic fibre technology to normal wear and tear is a fatal flaw in this approach. That's an excellent observation (sadly not a common property of Slashdot comments these days) and worth looking into. Not for any practical purpose, as I doubt I'm likely to get rich off what amounts to idle speculation, but purely out of fascination over what sorts of solutions are being overlooked.

      • by cortex (168860)
        Any wired solution, electrical or optical, must cross the skin therefore presenting a big infection risk. The whole idea behind using wireless devices in neural prostheses is to remove this risk of infection.
      • Why fibers? Skin is translucent enough.
        • by jd (1658)

          Direct interfacing means that you can run two fibres that can carry every signal from every synthetic nerve ending in a bionic hand or leg, demultiplexing somewhere in the body. (So this will still work if someone loses a leg and has spinal damage that breaks the nerves before they reach the point where the limb is lost. Demultiplexing in the spine would require a clever design to keep within space constraints but there are no technical constraints at this point. Mixed-mode silicon is commonplace, ADCs and

  • why wifi what happens when more then one person is in the same area with the implants.

  • by Anonymous Coward on Wednesday November 23, 2011 @07:46PM (#38154442)

    .. Please turn off your arms and legs during takeoff.

  • This is one of the cases where you need reliability.

    • by Anonymous Coward

      you also don't want to run wires through the protective membranes around the spinal cord.

  • by mj1856 (589031) on Wednesday November 23, 2011 @07:53PM (#38154498)
    would bring them to their knees....
  • by erroneus (253617) on Wednesday November 23, 2011 @07:57PM (#38154518) Homepage

    From the sound of it, prosthetic designers and engineers are planning devices that operate on single frequencies.

    The animal brains and nervous systems operate quite a bit differently. The signals do not often rely in a single path or a single signal to make things happen. To transmit a true, low-power signal, multiple paths and multiple signal details are transmitted where it is the collection of these signals which spell out the truth. If there are minor glitches, interferences or inhibitions along the way, the general signal still gets through most of the time.

    If they are thinking of making a brain to prosthetic control signalling system based on wireless communications, it would be a huge mistake not to use multiple signals and frequencies to make things happen as this is the way the brain and the nervous system already does things.

    I find this to be the mistake they are likely to make as they made the same mistake with artificial blood circulation system which are intended to keep the body alive during heart surgeries. Initially, they just hooked up a streaming pump and wondered why the body wasn't working or surviving under that condition. Well, turns out that the body NEEDS the pumping and gushing style of blood circulation because as the blood is pushed, it still needs those moments of pause to absorb and distribute oxygen and other stuff like that.

    I expect the mistake to be made. Now let's sit back and wait for it to come true.

    • Actually, no [slashdot.org] to that last one. But the rest about redundancy is spot-on.
    • by Grishnakh (216268)

      Initially, they just hooked up a streaming pump and wondered why the body wasn't working or surviving under that condition. Well, turns out that the body NEEDS the pumping and gushing style of blood circulation because as the blood is pushed, it still needs those moments of pause to absorb and distribute oxygen and other stuff like that.

      No, it doesn't. By the time the blood gets to your capillaries, there's little pulse left. They're working on artificial hearts right now that'll leave patients with no pu

    • One clarification - the heart may need those pulses, but the rest of the body does not seem to need them. From NPR June 13th 2011, "Heart With No Beat Offers Hope Of New Lease On Life": "The pulsatility of the flow is essential for the heart, because it can only get nourishment in between heartbeats," Cohn says. "If you remove that from the system, none of the other organs seem to care much."
      http://www.npr.org/2011/06/13/137029208/heart-with-no-beat-offers-hope-of-new-lease-on-life

  • ...probably isn't that far away from happening, even if you argue that brain signals are too complex to analyze, the human body too complicated to replicate. When that future comes, you can bet there will be a non-negligible population of (possibly remote) prosthetic body users, and the required bands of frequencies (even taking into account such development as cognitive radio) will definitely be more than just four. Seeing how the wireless space is crowded now, how do we overcome this?

    • It's simple: we take every journalist who ever misunderstood quantum entanglement and assumed that it was a viable method of information-passing, and then make them interact at a subatomic level so that they adopt opposite spins (one liberal, the other conservative.) To pass information, we simply adjust the spin on one of the journalists, and due to misunderstanding quantum entanglement, his or her partner will automatically adopt the opposite spin.

      Then we do this several billion times per second.
      • by rwa2 (4391) *

        Don't forget that they can only be used once and then have to be discarded! Oh, if only that were true of politicians too!

        • Unfortunately the only flaw with such a system is that, unlike most forms of communication based on misunderstood quantum entanglement, your information gets leaked to the public before it arrives.
  • Just so you know, some folks who are far more technologically advanced than us have worked out a solution to this problem. That's why the Visitors have settled on the standard anal implant interface.

  • The augs are already here!

  • by Genda (560240) <mariet AT got DOT net> on Wednesday November 23, 2011 @08:26PM (#38154654) Journal

    This is not a problem. You take a body stocking made of lycra (this serves both as a scaffolding for signal transmission and reception and with small actuators it could also serve to enhance circulation, exercise muscle groups and protect the wearer from minor scrapes and scratches.) On the skin side of the suit, you place a mesh of conductive fibers and control nodes all over the entire body creating a large network of antennas for transmitting and receiving signals anywhere on the body. The outside of the body suit has a tight mesh attached to a device that converts ambient RF energy into useable electricity. It also serves as a highly effective barrier between signals inside and outside of the suit. By ensuring that the signals inside the suit are at least a couple orders of magnitude larger than the signals from outside the suit, the problem of unwanted control of the users limbs is rendered moot.

    One other idea might be to make the suit opaque and use an optical network with light fibers and choose IR frequencies that pass readily through human flesh to the neural interfaces. This produces no external signals if the suit is in fact optically opaque, and the isolation from the external environment would be absolute (save the flash from something like a thermonuclear device and then the crosstalk with the bionics is probably the least of one's concerns :-)

    • by skids (119237)

      Pantyhose. Is there anything it isn't good for?

    • ..

      Aren't you just repeating the backstory to the TV show, "M.A.N.T.I.S"?

    • Unfortunately that means you have to wear a spandex bodysuit all the time. That's not going to be desirable to someone who just wants to wear shorts and go for a walk in the park without looking weird.

      To just isolate spectrum you can just run an optical fiber down their leg. Maybe have a little velcro band to strap it down in one or two places so it won't flop.

      But wireless is really the way to go if you can get a small band of reserved low power spectrum.

      • by mangu (126918)

        Unfortunately that means you have to wear a spandex bodysuit all the time. That's not going to be desirable to someone who just wants to wear shorts and go for a walk in the park without looking weird.

        If only there existed a way to make skin-colored spandex...

  • The age of mobile phones and satellites has made astounding improvements in transmitting and receiving RF energy. Why is the spectrum so limited? Why can't we squeeze thousands of times more sub bands inside any signaling band? Why shouldn't a 1MHz wide band hold as many channels now as an entire GHz used to hold when we weren't as good at this?

    • by doshell (757915)
      The Shannon-Hartley Theorem [wikipedia.org] places a fundamental limit on the data rate you can squeeze into a given bandwidth (for a given noise level). That said, I believe current technology is nowhere near this limit.
      • by Anonymous Coward

        Oh yeah, it's approaching the limit. The ~100mbps in 20mhz that LTE gets amounts to 5 bits per second per hz, and the theoretical limit is about 6 bits per second per hz. The future increases in overall channel capacity for cellular use amount to ways to reuse channels more tightly -- beamforming for instance uses dual transmitters nearby to each other, it can transmit so the two signals constructively interfere in the preferred direction, while cancelling each other out in other directions. Current

    • by Ol Olsoc (1175323)
      In principle, there are methods, like phase angle modulation, that by adding more and more angles of modulation, can accomplish infinite bandwidth. Unfortunately, the needed power levels approach infinite very quickly.

      But your question is not unusual, In this digital age, very few people outside RF engineers understand that there is only so much spectrum available. Compounding th eproblem, much of it is not useable for digital communications. The HF spectrum, for several years now looked upon by digital

  • Whatever happened to using a phased array to either/both direct a beam to a point, or to detect the point from which an omnidirectional transmission was received? Shouldn't these little grids be cheap and common by now? Then we wouldn't have to register every frequency to a licensed operator, but instead any signal would be a unique station based on where it came from and/or where it was sent.

  • Your garage door opener is using the same channel as my penile implant. Quit hitting the 'down' button when I'm getting it on with the wife.
    • by beaviz (314065) *

      Your garage door opener is using the same channel as my penile implant. Quit hitting the 'down' button when I'm getting it on with your wife.

      Fixed!

  • This sounds like a perfect recipe for meat puppets and remote crime!
  • Slightly off-topic, but as this technology becomes more practical in terms of day-to-day use (ie: it actually helps a physically disabled person significantly, and is well beyond the proof-of-concept and various stages of cost analysis and FCC regulations), would it be possible that people could find these solutions being awarded in court cases?

    I've noted a number of car accidents in North America over the years as they pop up in small-time newspapers, and a few months later the defendant is lucky to get
  • Let's hope that this slice of the spectrum stays out of the hands of private industry, or at least is very heavily regulated.

    I can just see a telecom sending a disabled vet a notice saying that he has exceeded his data cap for his wireless network and will now be charged $20 per each additional MB.
    Plus, his bandwidth will be cut in half.

    And he can only purchase peripherals (like fingers) from his wireless provider, so they can "guarantee a uniformly excellent end-user experience".

    It is for future applicatio

    • by mangu (126918)

      I can just see a telecom sending a disabled vet a notice saying that he has exceeded his data cap for his wireless network and will now be charged $20 per each additional MB.

      If it gets heavily regulated he could be arrested for masturbating himself, because if he pays for sex it's prostitution.

  • I need a hand here. No, wait....

  • Is Lee Majors still alive?

  • I, for one, welcome our new botnet overlords.

  • Wireless? Sounds really 'secure' .... 'I did not kill him! At some moment my limbs started to moving by themselves... someone must've hacked into me!'
  • This is another example of some organization selling off what belongs to everybody. It would be a different proposition if we were to decide who would get this bandwidth, at no charge. I posit that this would resolve a great many issues.

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