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XtremeBrain Interface

Implanted Electrodes plus Induction
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I should register XtremeBrain as a trademark, heh heh.

Several decades ago there was a fair amount of experimentation that involved electrodes planted in the brain. Various sections like pain and pleasure centers could be remotely stimulated. Larry Niven wrote some SF stories about "wireheads" who were addicted to the pleasure-stimulation thing. The connection gadget that plugged into their heads was called a "droud".

Alas, that sort of direct connection is not safe. The place where the hardware breaks through the skin of the body is a place where infections can get around the edges of the skin, and do damage. Constant medication is necessary to keep infections at the implant-sites under control.

Well, It Doesn't Have To Be Done That Way. Suppose a network of electrodes were implanted in various places, and all lead to a particular area UNDER the skin. A small coil at the end of each electrode, flat under the skin, is basically an antenna. And since the implants are entirely inside the body, no infections will occur after the normal surgery-recovery time.

This XtremeBrain Idea theoretically solves a problem related to "reading" brain signals, since they are being brought to the surface where antenna emissions, very-low-power though they would be, can still be detected easily with standard EEG gear. Furthermore, these are "deep brain" signals, and not just the surface signals that an EEG normally picks up.

Next, since antennas work both ways, the implanted XtremeBrain electrodes could have a signal easily INDUCED in them by an entirely external device. You could strap that device against the skull and let it induce signals in any/all of those electrodes, as appropriate. This is a MUCH lower-power approach than any other direct-brain-influencing induction technology that I've ever heard about before.

Vernon, Jun 08 2006


       how is a use of induced current a reducer of required current? also, what does "Xtreme" have to do with this?   

       this could only be powered off of batteries that have inductors hooked up to them [inefficiency], can't use dielectric material effectively for flux transmission [inefficiency], requires rectifier implanted at each of the sites for D.C. [space concern], has nothing to actually attach to.   

       i just don't get it.
tcarson, Jun 08 2006

       [tcarson], there are existing experiments that try to directly induce currents in the brain. These gadgets would consume a lot less power if an antenna/electrode system existed. PERHAPS, in the future, when much more is known about the parts of the brain to stimulate, and with more precise frequency-control of the stimulus-electronics, including perhaps focussed masers, a low-power method can be found that can work without buried antennas-electrodes.   

       Anyone wanting to undergo surgery to have their brains wired, when so much remains to be learned about interfacing the brain to the outside world, could be considered doing something Xtreme.   

       Your notion that the external stimulation-gadget can only be powered by batteries is ridiculous. A stationary one can be plugged into a wall, and a portable one could be powered by solar cells that cover a hat.   

       I'm not sure what you are getting at with respect to dielectrics. With no buried electrode, whatever problem you have, to get a signal into the brain, is going to be a more difficult problem.   

       Your nonsense about diodes is ignoring such modern thin gadgets as RFID tags, complete with an enormous number of transistors, diodes, capacitors, etc.   

       I'm not certain that stimulating the brain requires DC, especially if they are considering/experimenting with electrode-less induction (always AC, that).   

       Your statement "has nothing to attach to" is meaningless without further explanation. Induction ISN'T SUPPOSED TO have a direct attachment!
Vernon, Jun 08 2006

       I'd be worried as you your sensitivity to magnetic fields. Obviously you'd never be able to have an MRI, but would you ever be able to walk the through an airport metal detector? How about ride an electric train?   

       On the side of infection, although you're not breaking the skin, you're still going to have to go through the blood/brain barrier. Doing so will increase your vulneralility to brain infections.
st3f, Jun 08 2006

       [st3f], those are pretty good points. However, I do think that with a Faraday cage over your head, you could get an MRI of the rest of your body when needed. And regarding brain infections, a recent issue (I have to look up exact issue) of "Scientific American" has an article about those early electrode-planting pioneers, and in animal tests they managed to have hardwired electrodes for more than 2 years, without medical problems. Of course, that was in the lab with appropriately clean facilities and probably also with various antibiotics. Nevertheless, think a moment about that phrase: "blood brain barrier". The brain is well-supplied with blood; fully 25% of freshly oxygenated blood from the lungs goes straight to the brain. (Do some math: assume 103-pound human with 3-pound brain: 100 pounds gets 75% so 33 pounds gets 25% of oxygen. That means, pound for pound -- or gram for gram -- brain tissue can consume 11 times as much oxygen as other tissues in the body.) Anyway, the blood-brain barrier exists between the blood vessels and the brain tissue. It doesn't necessarily exist as a sheet between the skull and the brain. So, an electrode that comes through the skull and passes between blood vessels is also potentially bypassing the barrier altogether, and not damaging it. (Of course, if I'm wrong about the barrier not completely surrounding the brain, I'm sure someone will tell me in short order, heh.)
Vernon, Jun 08 2006

       vernon, personal electronics work on direct current. induction requires a variable magnetic field. there would be inefficiencies in the induction of current because the coils are separated by all of that tissue and bone, which isn't as good for the transfering of magnetic fields as certain dielectrics. you could plug these into the wall, put no one will be interested in being tethered like that what's the point in having the implant at all at that stage? the surface of the head isn't large enough for a solar panel that will power this, and solar panels are once again d.c. you can't use a faraday cage in an MRI because the cage itself will set up a reciprocal current through induction and effect the implants. when i said that there was nothing to connect these implants to, i was saying that we have no inputs for them. you'll have functioning brain links that don't have any purpose. how the hell am i ignoring things like rfid and thin electronics?
tcarson, Jun 08 2006

       tcarson: I think Vernon intends the coils to be immediately subdural so that they will effecively pick up an AC current from a similar coil held to the outside of the head. This current is then delivered to the centre of the brain via the implant. The simplest version of this would just involve an open loop of wire with the insulation stripped off that the ends. Thes ends would then be inserted where you want to deliver the jolt.   

       Vernon. I'm fairly certain that the blood-brain barrier covers the brain completely, but the optic nerves and spine have to come out somewhere.   

       The MRI was a pretty flippant comment as I don't think a person with a metal implant of any kind can have an MRI. Not certain, though. It might only be ferromagentic materials.   

       Not having any idea of the sensitivity of the brain to small currents, I wonder if you'd get a buzz just by spinning yourself around in the Earth's magnetic field. Guess not.
st3f, Jun 08 2006

       This is pretty well baked. 1: Stuff is implanted in the brain all the time. [V] is right in that it can be made safer if the overlying skin is intact. 2: [st3f] - you can have an MRI with metal. Consider: fake hip. It just cannot be ferrous. 3: Below is a chunk of text cut from a scholarly journal article which I do not think is freely available on line. People undergo essentially what [V] described, but to control seizures.   

       Electrical Stimulation of the Anterior Nucleus of the Thalamus for the Treatment of Intractable Epilepsy *John F. Kerrigan et al. Epilepsia Volume 45 Page 346 - April 2004   

       The intracranial stimulation leads were Medtronic 3387 DBS Medtronic, (Minneapolis, MN, U.S.A.) depth electrodes with 4 platinum–iridium stimulation contacts (each contact 1.5 mm wide with 1.5 mm edge-to-edge separation). Stimulation lead implantation was achieved by using a CRW stereotactic frame. Target sites were selected from magnetic resonance (MR) images, by using 1-mm-thick axial, coronal, and sagittal spoiled gradient echo (SPGR) pulse sequences. The target site (ANT) was identified on each side by visual selection, with reference to a standard stereotactic atlas (9).   

       During surgery, a guide cannula was inserted through a burr hole, and advanced to a point 10 mm from the desired target. In three of five patients, a monopolar single-unit recording electrode (Advanced Research Systems, Atlanta, GA, U.S.A.) was initially introduced to confirm the anatomic depth for entry into thalamic tissue after traversing the lateral ventricle (Fig. 1). The electrode tip was initially positioned within the lateral ventricle, where no units were recorded, then advanced until units were first recorded (superficial surface of ANT), and then advanced until units ceased (intralaminar region) and then recommenced [dorsomedian (DM) nucleus of thalamus]. The single-unit recording electrode was removed, and a temporary stimulation lead (Radionics Stimulation/Lesioning Probe, Burlington, MA, U.S.A.) was then introduced to elicit the driving response (see later). This was then removed, and the Medtronic 3387 DBS stimulation lead, with an internal stylet, was then inserted through the guide cannula to the desired target. The stylet and cannula were then withdrawn under fluoroscopy, after test stimulation demonstrated no adverse events.   

       The programmable pulse generators (Medtronic 7424 ITREL II Pulse Generator, Medtronic, Minneapolis, MN, U.S.A.) were surgically placed into a subcutaneous pocket in the subclavicular region and connected to the stimulation leads by means of a lead extension (Medtronic 7495 Lead Extension, Medtronic, Minneapolis, MN, U.S.A.), which was tunneled under the skin of the neck and scalp. Electrically independent pulse-generation systems were placed on each side (i.e., bilateral ANT implantation). Placement location of the stimulation leads was confirmed with either cranial computed tomography (CT; n = 1) or MR imaging (n = 4) (Fig. 2).
bungston, Jun 08 2006

       There are also recently invented nanowires (piezo-electric??) if anyone's read about them. Theyre expected to be able to power medical implants through kineses of your body. Would make the concept of a powered permanently implanted device plausible....
Half-life below 40yrs, Jun 08 2006

       [bungston], thanks. I was thinking that the XtremeBrain Interface idea would involve a LOT more electrodes than what they are doing to stop seizures. It would be nice if enough I/O could be accommodated for direct mental control of external hardware (and lots less biofeedback training that is currently assumed would be associated with noninvasive external EEG-type sensors).
Vernon, Jun 09 2006

       Uuuummmmm... sorry man it has too many flaws and it sounds to apple like...
crash, Jul 17 2010


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