Body Temperature Regulation Implants
edited February 2015 in Coatings, transdermals, other 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?
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.
Just imo :)
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.
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.
@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.
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.
What are the chances of safely creating/using antifreeze proteins like fish and other critters do? http://en.wikipedia.org/wiki/Antifreeze_protein
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.