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Can you see why?
15 responses to “Brain in a Box”
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Remind me of the Ant’ s nest blue print =)
Looks a lot like the different levels or neurones all the way up to the surface…
Or some kind of emerging neuronal architecture in gel, made by some genetically modify ants O=)
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Cool. Looks like an Elastrat phantom. It also looks very old or poorly kept — they are water-clear when new. Fun to make them (we made similar ones in our lab in grad school), but very labour intensive. It’s a "lost-wax" process, where the cores (blood vessel segments) are cast individually in water-soluble jeweller’s wax or a low melting point alloy (Cerrolow), and then joined together to make the complex 3-D shape. Fluid couplings are added and then the whole thing is cast in silicone. After a week or so of cure time the cores are then melted and dissolved out.
We used them to investigate flow in complex vascular geometries in optical, x-ray CT and MR imaging, but they are also used for training or demonstration. Incidentally, the first vascular flow models like this were made in a more, er, invasive (and messy) process from real vasculature. They were necessarily each unique, as you can imagine.
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[http://www.flickr.com/photos/imager]
!!
Now I remember fetal pigs, with arteries of red latex… -
The top box looks like some sort of logic gate, with pairs of inputs on top, and some other set of control inputs on the side, as if by pouring various fluids in at the top, you could influence which one flows out the bottom.
Or maybe it’s upside down and fluid entering from the bottom could be influenced to come out of a particular output at the top.
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[http://www.flickr.com/photos/34420997@N05] You got it.
[http://www.flickr.com/photos/85184175@N00] you just gave me the brilliant idea to make a fluidic computer in the shape of brain vasculature.
I’ll call it Yorick, and have it use a shakesbeerean algorithm to select from which keg to draw beer! (Two beer or not two beer… logically) 🙂 (ouch, sorry)
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[http://www.flickr.com/photos/imager] Bingo! With your first guess that is. =) With your second, if you could mimic the degree of interconnect fanout, and ideally have it be dynamic, that would be very promising. =)
This vascular phantom is aged, as it helped launch two startups! It was used by the development team to test the maneuverability of micro-catheters up from the aorta to potential sites in the brain. In one case, they were emulsifying blood clots in the brain (a type of stroke) without thrombolytic drugs. In the other company, they used a laser and disposable catheter.
[http://www.flickr.com/photos/photonquantique] – I love those visual associations, as there are similar elements of organic growth in each… a resonant homology in nature.
I was trying to find that very cool ant nest cast, but I was thinking of the termites so I could not find it. Thanks for the reminder!
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So they were actually flowing fluid…("blood") through this…to test the catheters..?
Hence the outflow "ports" on the top ?
Pretty clever…and you can watch without using X rays..
Though I would have though a lot of companies already have a ton of data like this…. -
I just got an interesting update from the entrepreneur who has this brain on his shelf:
They actually harvest the mold from a real cadaver. And then in a painstaking fashion remove/dissolve the scull and brain tissue around it so they can cast the negative, which is what we get. Nowadays you can buy glass models. But the advantage of this one is that it goes past the M1 segment of the arterial vasculature and into the distal M2 (~ 1mm ID vessels of even greater tortuocity near the distal ends of the model). These are hard to get from a glass model (if not impossible).
You are correct about the use of the mold. It was used to qualify neurocatheters that eventually made it to a human vasculature, specifically to qualify pushability (the amount of force it took to push a specific catheter design to a given point into the brain from outside the body (femoral access), and other mechanical durability tests.
But we can say that the first green pulsed laser that was fired into the human brain was with a microcatheter that was qualified with that model.
[http://www.flickr.com/photos/daveh56] – Yes on the fluid:
Indeed all the tests are performed when the vessels are filled with some fluid. It is imperative, otherwise no microcatheter would be able to make it far into the vasculature if it was not hydrophilically coated on the outside. Of course to “activate” the coating it has to get wet, hence always test with liquid-filled vessels.
Most of the time it is water (easy and convenient). For some more rigorous QA tests at the end of the catheter design and before human clinical trials, we used blood; heperinized (anti-clotting drug) porcine blood readily available from local slaughter houses. The things people do in medical device work… =)
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Uhm… yeah. That’s the messy part. Boiling sodium hydroxide solution does a remarkable job removing tissue from vascular casts.
But by the early 90s non-invasive 3D MR and CT imaging were good enough to produce full 3D models of in vivo vasculature, and from those numerical models we CNC milled 2D molds to produce the cast segments then assembled (and sometimes bent) into the 3D vasculature. We could reliably produce vessels down to 0.8 mm (determined by the 1/32" mill cutter). The neat thing was that you could synthetically add things like stenoses and aneurysms to the model. I left that operation a long time ago, but I think they are still commercially produced this way.
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