A View from David Zax
Could This Brain Implant Revive Paralyzed Limbs?
Researchers at the University of Michigan take another step towards the Holy Grail of neurological technology–a device that would restore natural movement to the paralyzed.
In the annals of great oxymorons, “non-invasive brain implant” would surely rank up there. Misnomer or not, the University of Michigan is touting just such a device, one that it says could have a range of applications–the most exciting of which is a potential ability to restore movement to paralyzed limbs.
That’s off in the horizon. For now, though, the BioBolt, as the implant is called, can act as an interface between the human brain and an external device like a computer. It’s not the first device to do so. But the BioBolt is distinguished from similar devices by its minimal invasiveness and low power usage. Whereas other neural implants require the skull to be open–rather drastically limiting the range of their usefulness–the BioBolt doesn’t penetrate the cortex, and it can be completely covered by the patient’s skin, crucial to fending off infection. (Still, points out MedGadget, this “minimally invasive” technology does require a wee-bit of skull drilling.)
The BioBolt, which Michigan researchers presented last week at a conference in Kyoto, Japan, is about the circumference of a dime, and has a small film of microcircuits clinging to its underside. When implanted in the skull, those microcircuits sit on the surface of the brain. There, they “act as microphones to ‘listen’ to the overall pattern of firing neurons,” explains an announcement from Michigan, “and associate them with a specific command from the brain.” The BioBolt amplifies those patterns, converts them into a digital signal, and transmits that through the skin to a computer. The final trick of using the skin as a conductor is what helps the BioBolt keep its power consumption low.
“The ultimate goal is to be able to reactivate paralyzed limbs,” said Kensall Wise, one of the engineers on the project. That’s years away, though. There are other potential uses of the technology in the meanwhile: with further research, it might be used to stem epileptic seizures, for instance, or it could be used to diagnose certain diseases, like Parkinson’s.
The Michigan research is part of a wave of new work that offers hope to the paralyzed. There are, in fact, devices approved by the FDA that can restore hand function and bladder control in some people who suffer from paralysis; brain implants that enable patients to move a mouse on a cursor have recently been demonstrated. In 2009, scientists were able to restore movement in a monkey’s paralyzed arm, using a system called functional electrical stimulation. “We can predict what the monkey is trying to do with his muscles and stimulate the muscles accordingly, essentially giving the monkey voluntary control through the computer instead of his nerves,” one of the researchers told Technology Review at the time. Numerous researchers have been involved in similar work, driving speculation that we could be entering a new era of telekinesis.
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