[extropy-chat] Research question: power supply for silicon-based neural prostheses

Anders Sandberg asa at nada.kth.se
Tue Mar 13 22:42:05 UTC 2007

pjmanney wrote:
> Just to be clear, I'm specifically looking to power a hippocampus
> prosthesis.

Just a note if you want some technical/surgical stuff: the hippocampus
gets its blood from the choroidal arteries and the blood leaves along the
vein of Galen, also known as the great cerebral vein. I think it has about
the same capacity as the sagittal vein I was talking about earlier, but it
is deep on the inside.

If you have heat emission problems, this arrangement perhaps will make it
slightly harder to do good cooling compared to my previous example where
one could actually add external heat sinks on the scalp (which is probably
a silly idea, but so what). So the constraints on the chip will be a bit
harder. But it is also next to the lateral ventricles of the brain, so
they can either be used as a heat buffer or as a place to put a few cubic
millimeters of extra hardware (the available volume is a few milliliters).

An interesting complication if the chip draws significant amount of sugar
is that it might give less sugar to subsequent parts of the artery-vene
loop. This is an obvious design problem and presumably can be solved by
linking it up to either the venes (the brain can't deplete all the sugar)
or some unneeded branch of the choroidal arteries (since you are replacing
stuff in the hippocampus you might take a branch that would have supplied
the excised tissue).

Anders Sandberg,
Oxford Uehiro Centre for Practical Ethics
Philosophy Faculty of Oxford University

More information about the extropy-chat mailing list