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The Challenges of Tapping Blood Flow For Power
joshuarrrr writes "Researchers in Switzerland have tested small turbines designed to fit inside a human artery, like an implantable hydroelectric generator. The turbines can draw about a milliwatt of power, which would be enough to run a pacemaker. The problem is that the turbines tended to create turbulence, which can cause blood to coagulate into clots. Competing systems avoid the turbulence but have trouble generating enough power."
As long as we're turning humans into batteries, we need to start pharmaceutical research on developing blue and red pills.
There's no -1 for "I don't get it."
The pacemaker just gives zaps to the heart which will beat on time. Its not supplying the energy to beat (which comes from glucose) but rather the command to do so.
You aren't, you are using blood pumped by the heart to power the signalling of the heart.
It's the same as spark plugs triggering ignitition in an internal combustion engine being powered by electricity being generated by that engine.
It's not perpetual motion because the actual energy for the work is coming from food or gasoline depending on which one we are talking about. Some of it is merely being siphoned off to use in keeping the device running.
A pacemaker that never needed to have its battery replaced would be quite an accomplishment.
That makes a hell of a lot more sense to me than what's discussed in TFA.
Any mechanical solution (using bloodflow to generate current) is going to impede the flow of blood through whatever vessel it's installed in, which is bound to cause complications of one sort or another. Not to mention the problem of tiny moving parts in a turbine operating in a tight, viscous environment. Why not run something like a fuel cell on glucose and oxygen instead? It's not like we don't have plenty of both to spare. Granted, you've then got to get rid of the resultant waste products, but that is one of the intended functions of the circulatory system.
It must be easier to mimic the metabolic functions of the human body. The support systems are preexisting.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
Not strictly on-topic, but as lots of people posted about the whole converting blood-borne glucose into electricity thing...
Woudn't having some device consume some of the glucose in your blood for its power then make _you_ feel rundown/lower in energy generally?
Probably because building a tiny machine that efficiently processes sugar into energy(without need for reagents that need to be replenished, wastes that the body can't handle, temperatures incompatible with tissue, etc.) is a task considerably more arduous than simply scaling down and producing in biocompatible materials a few simple mechanisms that some of the brighter classical greeks probably new about.... Biological metabolisms are impressive systems; but Not simple ones.
(Incidentally, if you want to lose weight without effort, throwing a wrench in your metabolism can do the trick, if done very carefully. A dash of 2,4-Dinitrophenol will cause the energy potential of the mitochondrial proton gradient, which normally goes into making ATP, to be dumped straight to waste heat. If you aren't careful, the hyperthermia will kill you; but so it goes...)
The alternate earth people in Robert J Sawyer's Neanderthal Parallax series used turbines like that to power implanted personal computers.
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You mean like they had back in the 1970s?
A car powers its own spark plugs. Same concept here.
I'm a biomedical engineering student in my last year of school. This idea is a non-starter. Regardless if the turbine could be redesigned to be more efficient, even the POSSIBILITY of a clot forming and causing the patient to develop a PE means it's never going to happen.
And there are more subtle effects than mere clots that happen when you put a medical device in contact with blood. Current technology does not have any solution for these problems, and has failed to find a fully blood compatible material for 40 years.
A much easier idea would be to make pacemakers rechargeable via electromagnetic induction. I asked one of the St. Jude reps why we don't do it this way, and the reason has to do with legal reasons : the non rechargeable pacemakers are less likely to fail and kill a patient.