Body Temperature Regulation Implants

While cooling the body down seems slightly tricky, heating it up seems fairly simple. Would it be feasible to implant arrays of high-efficiency heating coils coated with silicon gel throughout the body, with either individual power sources for each array, or an induction grid in a jacket with an external source?


  • Sounds like a really unpleasant way to kill yourself...
  • In what way? Electrocution or getting roasted?
  • Getting roasted, mostly.  I mean, in principle, this might be a good thing, but our bodies aren't exactly made to be modular, so any attempt to heat it up with an internal heating coil will probably just end up boiling you to death, at least by any way I can think of offhand.  If you have a solution, though, or can come up with one, I'd love to be proven wrong on that point.
  • Our bodies are fairly good at distributing heat, so the "many locations" thing might not be needed.

    Could "being cooked" not be easily prevented by heating the system up to no more than 40°C? It would still be a local hot spot and heat would be actively distributed from it, but no cooking should occur since (most) proteins start denaturating around 60°C.
  • The issue I see, and the reason for a large number of implants, is compensating for a drastic temperature spike. More implants would distribute the heat slightly better and keep a more sparse system from flash-frying the area surrounding the implants in an attempt to combat the sudden drop. So we obviously need to have some safety features...

    Any thoughts on what we could use to protect against an outside current or a shorted coil from roasting you alive? Aside from not implanting it at all, that is...
  • edited November 2013
    how about actual coil monitoring for each coil? it's not hard to add a tiny temperature sensor and having turn off a powermosfet which prevents current from flowing in the coil.

    and now it's time for my pessimistic estimates:
    75Kg human * 4184J/kg*K = 313.8kJ/K
    so for each Kelvin to raise , you need to pump 313.8kJ worth of heat into the body.
    an implant-friendly 24x25x5mm li battery stores about 5.3kJ.
    a very common laptop standard cell, the 18650 is about 8Wh, or ~29kJ
    so given the gravimetrical energy density of lithium battery technology you get between 350 and 500kJ per kg.
    So for every kelvin you wish to heat your body, prepare to implant 500g worth of battery. not counting the charging circuits.
    Not taking into account the actual body reaction such as sweating, to compensate for overheating.

    now that i shot big holes into an implanted power source version let's take aim on external powered induction heating. It's true that the implant can be a lot simpler, every conductive and coated object will do more or less. you still need the induction on the jacket, and even more power supplies to carry around, since you have to take the losses of the inductive power circuit into account.
    given all the weight, size, and complexity i'd rather recommend to just add heating pads to your jacket, they are cheap, widely available, they don't require implantation or difficult circuitry. you could bluetooth couple an implant with temp sensor and your jacket. but even then. a simple switch would work just fine.

    a ways more robust sollution would be to buy/sew/aquire a loden cape. they are hard to get hands on these days as high quality loden is rather difficult to find. but if you can find one, they do an excellent job, not only keeping you warm, but also dry, even during hours of stormy and rainy weather.
  • So using electricity for such a device seems impractical. What about using a different heat source, like a chemical reaction or microorganisms?

  • chemical reactions are often hard to control, and even harder to reverse. i sort of doubt microorganisms would do a lot.
  • Sodium Acetate solutions are what are used in those crack and go heating pads, easy to reverse.  Not really suitable for implantation though, especially due to the temperature needed to reset them.
  • edited November 2013
    How long does it take the crystals to transform back into a solution during the heating process?
  • in boiling water, about 10 to 15 minutes. the minimum temperature for it would be 58°C. which would be quite uncomfy already. besides all that. the energy density is even below li-ion (a mere 290kJ/kg , with li-ion beeing between 300 and 500kJ/kg).
  • What are you trying to accomplish? If you just want heat, take 3'4' dinitrophenol. Depending on the dosage, you can either run around nude in ice, or cook your innards.
  • In any situation where it is desirable to increase one's body temperature by the dramatic amounts offered by DNP, DNP is almost certainly the least desirable available option. If I'm trapped in an environ where hypothermia is a pressing danger, in all likelihood I'm also short on sustenance and rescue is not forthcoming. Burning through what remaining stored metabolic energy I have is far from a viable option.

    Just imo :)
  • Saal pretty much hit on what I'm trying to accomplish.

    I hesitate to suggest this option, simply because of the danger, but would RHUs that are properly shielded and sealed, and controlled via moderation, be suitable for this purpose?
  • i really feel like thermal regulation is best done outside the body. minimizing heat loss is way more effective than generating additional heat loss. space blankets to block thermal radiation, insulating layers to trap the warm air, and some weatherproof shell like a bivac would be smaller, lighter, simpler, and more effective.

    about radio isotope heating. there's a case of a hiker who got trapped in a snow storm (i think it was in italy). he found some barrels which were warm so he spend the night near them. the next day he had to be treated in a hospital with severe radiation injuries because the barrels contained illegally disposed nuclear waste.

    so once again my recommendation space blanket, felt, water/windproof bivac.
  • What if you get wet? 

    And Radioisotopes that are Beta or Alpha emitters, like Polonium-210 and Plutonium-238, would be relatively safe to use, because Alpha and Beta radiation can be blocked very easily, using materials like aluminum foil. And in the case of plutonium-238, the cell would last over 20 years...

    Although i heard about that hiker too. That's part of what gave me the idea in the first place.

    In regard to your previous suggestions, any thoughts on passive methods of Body temp regulation via biohacking? I already saw 3'4' dinitrophenol mentioned. What about surrounding major arteries/heat radiation points with an electroreactive material serving as a variable insulator. Or drugs that increase the contraction of capillaries and blood vessels more rapidly than normal, or beyond the normal response.
  • edited November 2013
    Cold thermogenisis is an effective and simple method of increasing one's tolerance to cold, as well as an effective weight loss method in combination with keto/paleo and an active lifestyle. I highly recommend it.

    Look into yoga, specifically pranayama. One can achieve remarkable control over one's biometrics (including body temp) with some of these (scientifically validated) methods; I believe @Cassox did a blog post on controlling blood pressure this way.

    You're really not likely to find a plug-n-play solution to this problem that doesn't carry at least a 75% chance of killing you.
  • Well, Now that we've covered Heating, What about cooling?
  • I'll post this link in both threads I guess. Cooling:

    @TheGreyKnight: I completely dig the idea of an implanted means to regulate homeostasis. Not sure how to handle the power issue, like ThomasEgi was saying. That said, this is not impossible. It's just an engineering issue.

    @ThomasEgi: I'm looking over your numbers above. Hypothetically, assuming I was heating my body by 1 kelvin, how long could I keep myself heated with that 500g battery?

    @Saal, @Cassox: I think that wristband in the link might be better than ice baths. What do you think?
  • those numbers neglect any thermal flow. it assumes 100% thermal insulation. so the actual numbers are ways lower.
    but to give you a rough idea: the energy demand of the average human is about 2000kcal /day (not being very active). that's about 8300kJ. with a 500g li battery you get about 150 to 250kJ.
    so a 500g battery can substitute your body's internal heating for about 30 to 45 minutes.
    i hope this makes it easier to see why i highly advertise to improve clothing to stay warm. a simple space blanket reduces heat radiation by 90% , in practice it may be a bit less. but such a blanket just weights a few grams, and helps so much more.
  • I'm looking at this wrong then. My thinking was that:
    8300kJ/24 hrs= 348kJ/hr 
    348kJ/37 degrees Celsius= 9.4kJ per degree per hr.

    this ignores a ridiculous amount of factors, but I'm guessing the main flaw in logic is that I can't just produce 1 degree, right? I'd have to produce 38 degrees continuously?
  • you can't just suddenly throw in 37K from nowhere. you can't "produce" temperatures either. the 348kJ/h is just the ammount of energy the body uses per hour so you don't die. most of it will end up as heat one way or the other. that's just to give you an idea about what ammount of energy the body deal with all by himself. compared to the energy you can carry around in a 500g battery. that number is in no way related to a certain temperature.
  • @ThomasEgi: There is obviously a semantic barrier here. My point was that an implant in a 37 C body is going to also be 37 C when not operational. Turning on the implant (let's say it is a resistor heater) will cause the implant to heat to 38 C. The body absorbs/diffuses/(insert correct term here) the heat as per one of the laws of thermodynamics, much of which is carried throughout the rest of the body via the circulatory system. Granted, the implant is continually having to create/produce/(insert correct word here) heat in excess of the diffusion rate to maintain 38 C. Even a tiny resistor heater in operation is going to be warmer than the surrounding tissues and create this effect even if perceived reward is negligible. The body is already warming itself to 37 C so the excess heat from an implant should be able to supplement the heat required to hit 38 C at a much lower energy cost than what you have in your figures. That was by my thinking anyway. I'll take your word for it.

    moving on from that idea, maybe some bio guys like @Glims or @Cassox can critique this idea:
    What are the chances of safely creating/using antifreeze proteins like fish and other critters do?
  • edited November 2013
    @DirectorX , my figures are not based on any thermal processes going on. Instead it's based the thermal capacity and the energy required to change the temperatures (the actual temperature does not matter, as it is purely based on temperature differences). That means, assuming you have a perfect system, with no losses, perfect distribution of the heat from the implant to the body, and the body loses no energy to the surrounding.
    It is a best-case calculation. Every effect you start to take into account will make the numbers even less promising.
    That's why i try to point out that heating with any kind of device is not very feasible. The body's internal temperature regulation is ways more powerful. So it's probably smarter to see what can be done with the body's existing system, maybe triggering the right responses to get the desired effects.
  • the wristband works on a different mechanism the cold thermo, i wouldn't compare them. cold thermo triggers metabolic pathways causing the body to burn more energy specifically from certain reserves. the effects can be quite long term and do more than just make one "used to the cold"
    i am also curious to see what the long term effects of repeated microtemperature shocks to a person will do.

    on the AFP question: using non standard proteins would be pretty risky. the other problem is that without a constant supply, they would be quickly broken down. Modding a mammalian cell to create these is probably possible i suppose, but it would be in vitro only, ie highly unlikely that you are going to be adding any new protein creation functions into a mature creature.

    another thing to note is that these only protect from freezing via reduction of ice crystallization. this is fairly normal in lots of things, if done other ways. it's even how we protect cells when preserving them in liquid nitrogen. the main thing to get out of this is that it does nothing to protect against cold per se. long before the ice crystallization properties were necessary, the body would have come to a crashing metabolic halt. as was pointed out with the cold thermogenisis comment, we have a lot of built in wiggle room. what AFPs would protect against are waaaay outside the wiggle.

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