Next Step for Darpa’s Mind-Controlled Prosthetics: Reliability
The Pentagon’s mad science division is closer than you’d think to creating thought-controlled robot limbs for a wide swath of wounded soldiers. The early experiments and prototypes have worked out. So now Darpa wants to iron out the crucial technical wrinkles—they are going to focus on fine-tuning.
The core of their new project – Reliable Central Interfaces – is prosthetic dependability. No “technology push,” no bleeding-edge scientific studies, the agency says. For this, Darpa wants to establish solid reliability.
This endeavor is the latest in a legacy of prosthetic research that reflects the Pentagon’s efforts to help injured soldiers regain limb movement. Combining scientists’ knowledge of neuroscience with cutting-edge interface technology, their aim is to decode cues from brain neurons and transmit them to limb prostheses, allowing the paralyzed to move again. And it’s very close to realization.
One of the ancestors of this technology in 2004 allowed paraplegic ex-football player Matt Nagle to move a mouse cursor, open his emails and use a TV remote control, all with his mind.
Then came the DEKA arm, the invention where nerves from the armpit were re-routed into the chest. So the “move” command went from the brain to the chest, where sensors transmitted the instruction to the bionic arm.
Another innovative leap was the Modular Prosthetic Limb; for the first time, microchips were transplanted into a human brain from where they attempted to send a move command (via a computer) to the robot arm. The ambitious technology is still a busy work-in-progress.
Although there have been some giant strides in this field, the finish line remains out of sight. And that’s where the RCI project comes in.
Now that the infrastructure is in place, Darpa wants to identify and attack the various obstacles that have cropped up at each stage of those ventures.
Their central focus: the human brain.
They’ve divided up the big problems into five main “technical areas.” One will focus on lengthening the lifespan and reliability of current micro-arrays that record communication in the brain, the keystone of the brain-to-limb project.
Another will address mechanical algorithms that decode the brain’s signals. These are essentially the brain’s translators and Darpa wants to improve their “language” skills so prosthetic limbs can understand them better.
A third area is an effort to fine-tune the sensory feedback from artificial limb to brain, to create smooth, natural movement in amputee subjects.
Darpa says that recent technical advances have shown that creating a dexterous, high-performance limb is definitely possible. But their concern is, as always, with pushing boundaries: will the technology ever be reliable enough so wounded soldiers can actually fight again? Can these soldiers ever strip and reassemble weapons on the field, with their bare robot arms?
If it works as planned, the brain-machine technology will not just be limited to amputated soldiers — Darpa has bigger plans for it. When it is perfected, it will be the single most enabling hope for people with disabilities. Linking up the brain with a computer means paralyzed people can overcome their two largest hurdles: independent control over their communication skills as well as their physical movements. Making the lame walk may sound like sci-fi. But it is tantalizingly within reach.
Photo: Johns Hopkins
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