Neuroscientists Join the Open-Source Hardware Movement

Two MIT grad students offer up DIY brain-recording gear

4 min read
Neuroscientists Join the Open-Source Hardware Movement
Photo: Open Ephys

whats in your EV? illustrationPhoto: Open Ephys

Graduate students Josh Siegle and Jakob Voigts were planning an ambitious series of experiments at their MIT neuroscience labs in 2011 when they ran into a problem. They needed to record complex brain signals from mice, but they couldn’t afford the right equipment: The recording systems cost upward of US $60,000 each, and they wanted at least four. So they decided to solve their dilemma by building their own gear on the cheap. And knowing that they wouldn’t be the last neuroscientists to encounter such a problem, they decided to give away their designs. Now their project, Open Ephys, is the hub of a nascent open-source hardware community for neural technology.

Siegle and Voigts weren’t knowledgeable about either circuit design or coding, but they learned as they went along. By July 2013, they were ready to manufacture 50 of their recording systems, which they gave to collaborators for beta testing. This spring they manufactured 100 improved units, which are now arriving in neuroscience labs around the world. They estimate that each system costs about $3,000 to produce.

Neuroscience has a history of hackers, Siegle says, with researchers cobbling together their own gear or customizing commercial systems to meet their particular needs. But those new tools rarely leave the labs they are built in. So scientists spend a lot of time reinventing the wheel. The goal of Open Ephys (which is short for open-source electrophysiology) is not just to distribute the tools that Siegle and Voigts have come up with so far but to encourage researchers to put resources into developing open-source tools for the benefit of the whole community. “In addition to changing the tools, we also want to change the culture,” Siegle says.

whats in your EV? illustrationOpen Ephys just distributed 100 of its acquisition boards to neuroscience labs around the world.Photo: Open Ephys

The flagship tool that Siegle and Voigts developed is an acquisition board, which makes sense of the electric signals from electrodes implanted in an animal’s brain. The board interfaces with up to eight headstages that amplify, filter, multiplex, and digitize signals from the brain, and then sends those signals to a computer for further processing. Commercial systems typically have individual ICs perform each of those four functions, but Siegle and Voigts’s system uses a single microchip for the four steps. The chip was recently developed by Intan Technologies, based in Los Angeles. “Once we realized these chips were available, it seemed kind of silly to keep buying the big systems,” Siegle says.

The president and cofounder of Intan, Reid Harrison, says that shrinking and consolidating the gear wasn’t that complicated—it mostly required initiative. “It’s such a niche market that no one else had tried to miniaturize the technology,” he says. “It’s not exactly on the scale of CPUs and cellphones, which drive most IC technology.” However, Harrison says he recognized a need for his small, multipurpose chips. Neuroscientists are always trying to fit more electrodes into an animal’s brain to record more neural activity, he says, which requires ever tinier devices with the electronics close to the electrodes. “You could put 1,000 electrodes in the brain, but you don’t want 1,000 wires on an animal that’s supposed to be mobile,” he says. The Intan chips take information from up to 64 electrodes and turn it into one digital signal, eliminating the confusion of wiring.

The major neural technology companies have designed products that incorporate Intan’s chips, but they also swear by their larger, multichip systems. Keith Stengel, the founder of Neuralynx, in Bozeman, Mont., says that in his big systems, each component is optimized for peak performance. “A lot of our customers have said that you buy a Neuralynx system for the serious work that you’re going to publish, and then you get an Open Ephys system as a second system, for grad students to start their research on,” he says.

whats in your EV? illustrationOpen Ephys offers building instructions for this head-mounted neural implant system for mice.Illustration: Open Ephys

Andy Gotshalk, CEO of Blackrock Microsystems, in Salt Lake City, also argues that the commercial products will continue to be the gold standard. “You’re not going to be moving into FDA clinical trials using an Open Ephys system,” he says. The commercial products come with guarantees of quality and reliability, he says, as well as intensive customer support. Gotshalk says his customers are willing to pay a premium for that backing.

Both Stengel and Gotshalk say they welcome Open Ephys to the market and think that its systems can fill a niche. They’re also willing to work with the upstart to make sure their commercial software works with the Open Ephys hardware. Harrison agrees that the community is happy to have another option to work with, and he draws a parallel to the computing industry. “The existing tools are like the PCs and the Macs of the neuroscience world, but now we also have this Linux,” Harrison says. “It’s a lot less expensive, and you can hack it yourself, but it’s not for everyone.”

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Restoring Hearing With Beams of Light

Gene therapy and optoelectronics could radically upgrade hearing for millions of people

13 min read
A computer graphic shows a gray structure that’s curled like a snail’s shell. A big purple line runs through it. Many clusters of smaller red lines are scattered throughout the curled structure.

Human hearing depends on the cochlea, a snail-shaped structure in the inner ear. A new kind of cochlear implant for people with disabling hearing loss would use beams of light to stimulate the cochlear nerve.

Lakshay Khurana and Daniel Keppeler

There’s a popular misconception that cochlear implants restore natural hearing. In fact, these marvels of engineering give people a new kind of “electric hearing” that they must learn how to use.

Natural hearing results from vibrations hitting tiny structures called hair cells within the cochlea in the inner ear. A cochlear implant bypasses the damaged or dysfunctional parts of the ear and uses electrodes to directly stimulate the cochlear nerve, which sends signals to the brain. When my hearing-impaired patients have their cochlear implants turned on for the first time, they often report that voices sound flat and robotic and that background noises blur together and drown out voices. Although users can have many sessions with technicians to “tune” and adjust their implants’ settings to make sounds more pleasant and helpful, there’s a limit to what can be achieved with today’s technology.

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