Incremental Advances in Machine-Nerve Interfaces

Computational hardware, electronics, and biotechnology are three of the most rapidly advancing fields of human endeavor at the present time. The years ahead are going to be most interesting, even though progress always seems far too slow and incremental while living it a day at a time. One field that sits within the broad overlap of machinery, computing, and biology is that of nerve-machine interfaces, which spans the gamut from the creation of machines to take on the job of a biological nerve structure, through simulation of nervous system behavior, through to attaching machinery to nerves in order to form a new gestalt system.

Examples of this work being demonstrated today are very crude in comparison to what will be possible in the future - but the path forward, while slow and incremental, definitely leads towards functional prosthetics that are fully tied into a biological nervous system. This sort of technology is important to the 2045 Initiative view of the future, but is less relevant to the SENS vision for human longevity, which is (rightly I think) focused on the biology we have and how to repair it.

Prosthetic technologies of all sorts are a competitor for regenerative medicine, both having the goal to alleviate serious injuries involving loss of body parts or their function. I'm not sure I see a viable outline for the next five decades in which increasingly sophisticated prosthetics can be used to extend life meaningfully - there are parts of the body that you can't easily replace with machinery, even once arbitrary neural interfaces are a robust and easily constructed concern, and so we must learn how to rejuvenate the brain and its supporting structures at a bare minimum regardless of what else happens. The biotechnologies needed for this goal do not seem likely to emerge until after the research community can already rebuild most of the rest of the body, as the brain is a far more complex structure of diverse cells, mechanisms, and cell types than any other organ.

In any case, here are two examples of the present state of play in nerve-machine interfaces of varying degrees of sophistication, both aimed at restoring function in cases of crippling injury.

The quest for a better bionic hand

Silvestro Micera, of the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, is paving the way for new, smart prosthetics that connect directly to the nervous system. The benefits are more versatile prosthetics with intuitive motor control and realistic sensory feedback - in essence, they could one day return dexterity and the sensation of touch to an amputee.

Micera and colleagues tested their system by implanting intraneural electrodes into the nerves of an amputee. The electrodes stimulated the sensory peripheral system, delivering different types of touch feelings. Then the researchers analyzed the motor neural signals recorded from the nerves and showed that information related to grasping could indeed be extracted. That information was then used to control a hand prosthesis placed near the subject but not physically attached to the arm of the amputee.

Walking again after spinal injury

In the lab, rats with severe spinal cord injury are learning to walk - and run - again. Last June in the journal Science, Grégoire Courtine, of the École Polytechnique Fédérale de Lausanne (EPFL), reported that rats in his lab are not only voluntarily initiating a walking gait, but they were sprinting, climbing up stairs, and avoiding obstacles after a couple of weeks of neurorehabilitation with a combination of a robotic harness and electricalchemical stimulation.

[Recently, he outlined] the range of neuroprosthetic technologies developed in his lab, which aim to restore voluntary control of locomotion after severe spinal cord injury. He explains how he and his colleagues are interfacing the central nervous system with stretchable spinal electrode arrays controlled with smart stimulation algorithms - combined with novel robotic rehabilitation - and shows videos of completely paralyzed rats voluntarily moving after only weeks of treatment. Courtine expects to begin clinical trials in human patients within the next two years.


I'm a "shaper". I prefer biotechnological approaches such as SENS rather than cybernetic enhancements. Russia's 2045 initiative is not very appealing to me.

Posted by: Abelard Lindsey at February 18th, 2013 10:21 PM

I have a couple points of disagreement here. Firstly, the idea that the brain is the most complex organ is a widely repeated claim that is usually assumed to be obviously true, but to me it is far less clear than that. From the standpoint of regenerative repair, I would venture that the lungs are the most "complex" organs.

Secondly, worthy though these advances may be, I don't think they can be seen as incremental steps toward the sort of mind-machine interface that could functionally replace the biological body. The latter task would require an interface with resolution at the level of individual cells. That cannot be approached through refinement of existing tactics, but would require something totally novel like self-assembly in vivo of arrays of conductive nano-wires.

One of the things that leaves me sceptical of the 2045 crowd is that I don't see anybody seriously discussing this issue even in theory. There is a lot of hand-waving, but no concrete plan to produce the necessary sort of nanotechnological interface the vision would require. Nothing that I've been able to find even proffers a possibility for consideration at the level of detail I described in the previous paragraph. Arguably this post is the most detailed plan of action ever produced for their approach, on the strength of a single sentence.

Posted by: José at February 18th, 2013 10:23 PM

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