The Man with the Bionic Brain
by Jon Mukand
Book notes - not a review or a book report, but facts I want to remember and thoughts I had while reading
Matt Nagle born1979 quad2001 braingate2004-2005 died2007
Jon Mukand rehab doctor, clinical investigator for braingate
- many others
- Cyberkinetics (Foxboro MA) Braingate team mentioned in book:
Braingate implant 10x10 "1mm wires", about 1.5mm square?
- wire bundle to outside contacts
should be an on-chip electrode array with driven shield under electrode pads for < 1fF contact C
- MOSIS can make single chips. With a low voltage (0.5V) deep submicron process, it could consume nanowatts and be powered and communicate with a coil, like a cochlear implant. Nothing should penetrate the skull and dura.
- electrodes fail over time. Scar tissue wrapping the contacts?
- metal sensor or stimulus electrodes do not generate the intercell messenger molecules that keep neighboring cells healthy.
- present day stimulus electrodes generate microamperes and volts. This is a blowtorch at the molecular scale. We must learn to use nature's high threshold, low power chemical signalling processes.
- someday, electrodes should be covered with sensor molecules that bind to neuro-molecules, not electric fields
- voltage cycle the electrodes to unbind the neuro-molecules, frequently. Doing this for billions of cycles will be hard.
- sensors like this are being used to detect DNA. Work going on at Sharp Labs Vancouver and OHSU CMOP.
Scar tissue is the big problem. Making any implanted device "bio-friendly" and "neuro-attractive" requires mimicking cell walls and generating the molecular messengers to attract the right connections and chemically signal neighboring cells to function properly.
Matt wanted "stem cell" repair. Seems unlikely without some kind of very sophisticated guided neuron-to-neuron repair. Chances are, every axon severed is dead and dissolved on one end of the break, because it is not connected to the nerve cell nucleus. This will require growing nerve fibers that are a good fraction of a meter long, and connecting them to just the right place. If the infant training process that builds the motor area and makes specific connections from brain to limb is heavily dependent on training, trial-and-error, and aptosis instead of specific genetically encoded pathways (neuron-specific pathways unlikely, DNA is not large enough), forget about it, you will need to replicate the whole learning process, or specifically and precisely lay down complete nets from muscles to specific cortex neurons.
Matt's eyes should have been the "mouse", and the implant the 3 buttons. Can seccades be intelligently filtered out? A "zoom and select" function could aid noisy movements, probably Cyberkinetics had some algorithms to filter "brain noise"
What if instead of trying to reconnect the unconnectable, we attach each muscle to an electrically controlled nerve stimulator, and control the entire musculature of the body from a computer, programmed to walk, eliminate on command, and exercise the body? If we can keep a quad standing and walking most of the time, breathing, and turning themselves in their sleep, we can reduce pressure ulcers, burn excess calories, and indirectly give the individual mobility.
The program could be selected with head muscle movements, speech, eye movements, or an implant. Assume a limited environment with external transponders for position, body orientation, etc. A quad might be limited to roaming an instrumented and mapped care center, but that would be a heck of a lot better than being a head in a bed.
Power for motors: fuel cell microcombustion is lighter than a battery. Swap fuel bottles during meals.
Can we someday expand skulls and stretch brains (lengthening axons???) over months or years to create room for artificial wiring channels? Or are we stuck with the volume and lengths that we have?
Steve Sapiro attempted to make a device that measured brain waves at Emotiv. Some say Emotiv measured facial muscle twitches. But what if facial muscle twitches are the best thing to measure? We communicate a lot of nonverbal information that way!
Signalling to and from brains will replace hands and eyes for computer communication over the coming decades. We will use muscle twitches, skin contacts, magnetic fields, myo-electricity, everything we can measure without cutting holes. In another couple of decades, we will invade the skull, looking for more bandwidth, as new technologies become safe and cheap enough for widespread use. The braingate is a tiny step in that direction.