Moving brain implant seeks out signals

Moving brain implant seeks out signals



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A device that automatically moves electrodes through the brain to seek out the strongest signals is taking the idea of neural implants to a new level. Scary as this sounds, its developers at the California Institute of Technology in Pasadena say devices like this will be essential if brain implants are ever going to work.



Electrodes implanted in the brain could, in principle, pick up neural signals and convey them to a prosthetic arm or a computer cursor.



...Joel Burdick and Richard Andersen at Caltech have developed a device in which the electrodes sense where the strongest signal is coming from, and move towards it. Their prototype, which is mounted on the skull, uses piezoelectric motors to move four electrodes independently of each other in 1-micrometre increments.



Tuning in



With the new device, which the Caltech teams calls an autonomous microdrive, an fMRI scan is enough to locate the electrodes in the general area where the signals are coming from. Each electrode then homes in on the strongest nearby signal.



Collision avoidance



To stop it damaging neurons, the microdrive has been given a collision avoidance capability. “If the signal voltage starts rising very rapidly we know we are in danger of puncturing a neuron, so it backs off,” Burdick says.



While the animal tests have shown that the microdrive can home in on the strongest neural signals, it is still too bulky to be used for people. The team is working with Yu-Chong Tai of Caltech, an expert in microelectromechanical systems (MEMS), to make a smaller version with up to 100 electrodes.



The researchers say that within a year they expect to be able to fit a paralysed person with a microdrive implant that will allow them to control a computer cursor and navigate the web.

We've got autonomously moving neural MEMS implants for controlling computers with your thoughts -- and we're supposed to think something as simple as retinal scanning displays using MEMS are such a wild and crazy idea that could never work, despite the incredible pace of miniaturization and cost reduction?



I've said it before that humans and intelligent machines are merging. And it's not just some wacky idea. It's an inexorable force of nature and evolution. As a Microvision investor, this idea has an important resonance.