AFTER buttoning up a lab coat, snapping on surgical gloves and spraying them with alcohol, I am deemed sanitary enough to view a robot's control system up close. Without such precautions, any fungal spores on my skin could infect it. "We've had that happen. They just stop working and die off," says Mark Hammond, the system's creator.
This is no ordinary robot control system - a plain old microchip connected to a circuit board. Instead, the controller nestles inside a small pot containing a pink broth of nutrients and antibiotics. Inside that pot, some 300,000 rat neurons have made - and continue to make - connections with each other.
As they do so, the disembodied neurons are communicating, sending electrical signals to one another just as they do in a living creature. We know this because the network of neurons is connected at the base of the pot to 80 electrodes, and the voltages sparked by the neurons are displayed on a computer screen.
It's these spontaneous electrical patterns that researchers at the University of Reading in the UK want to harness to control a robot. If they can do so reliably, by stimulating the neurons with signals from sensors on the robot and using the neurons' response to get the robots to respond, they hope to gain insights into how brains function. Such insights might help in the treatment of conditions like Alzheimer's, Parkinson's disease and epilepsy.
"We're trying to understand what is going on inside this brain material that could have direct implications for human health," says Kevin Warwick, Reading's head of cybernetics, who is running the project with Hammond and Ben Whalley, both neuroscientists.
The team are far from alone in this aim. At a July conference on in-vitro recording technology in Reutlingen, Germany, teams from around the world presented projects on culturing brain material and plugging it into simulations and robots, or "animats" as they are known.
To create the "brain", the neural cortex from a rat fetus is surgically removed and disassociating enzymes applied to it to disconnect the neurons from each other. The researchers then deposit a slim layer of these isolated neurons into a nutrient-rich medium on a bank of electrodes, where they start reconnecting. They do this by growing projections that reach out to touch the neighbouring neurons. "It's just fascinating that they do this," says Steve Potter of the Georgia Institute of Technology in Atlanta, who pioneered the field of neurally controlled animats. "Clearly brain cells have evolved to reconnect under almost any circumstance that doesn't kill them."
After about five days, patterns of electrical activity can be detected as the neurons transmit signals around what has become a very dense mesh of axons and dendrites. The neurons seem to be randomly firing, producing pulses of voltage known as action potentials. Often, though, many or all of them will fire in unison, a phenomenon known as "bursting".
There are various views on what these bursts are. Some see them as pathological activity - akin to what happens in epilepsy - while others see them as the neural network expressing a stored memory. "I interpret them as seizure-like behaviour," says Potter. "I think the bursting is a function of sensory deprivation."
Like a creature with no limbs or senses, the cut-down brain is simply bursting out of boredom, says Whalley. "With no structured sensory input the hypothesis is that you get arbitrarily random and quite often detrimental activity because all these cells are asking for some kind of direction."
To test this notion, Potter's team "sprinkled" pulses of electricity across a number of contacts on the multi-electrode array (MEA), to simulate sensory inputs, and managed to significantly quell bursting activity. "It seems that sensory input is setting the background level of activity inside the brain," says Potter.
These results have encouraged the researchers to begin investigating disease pathology with robots controlled by the cortical cultures. If they can make a robot do something repeatedly by sending signals to the culture, and then alter the brain chemically, electrically or physically to upset this controllability, they hope to be able to work out some causes and effects that throw light on disorders such as Alzheimer's.
To do this, Whalley's colleagues Dimitris Xydas and Julia Downes started by connecting a culture to an ultrasound sensor in a wheeled robot. They then record the spikes of voltage produced at points within the culture when signals from the sensor are sent to it. When they find an area that fires consistently when the sensor input reaches it, those signals can be picked up by an electrode and used to, say, make the robot avoid an obstruction. For example, if the ultrasound sensor indicates "wall dead ahead" with a 1 volt signal, and a certain knot of neurons in the culture always generates a 100-microvolt action potential when that happens, the latter signal can be used to make the robot steer right or left to avoid the wall.
To do this, of course, they need to connect their brain culture to the robot. Because it is living material, it needs to be kept at body temperature, so the control system is placed in a temperature-controlled cabinet the size of a microwave oven and communicates with the robot over a Bluetooth radio link.
The robot then whirrs around a wooden corral, and in about 80 per cent of its interactions with the walls manages to successfully avoid them. The researchers now plan to plot neural connections before and after such extended journeys to see if the connections are strengthening, says Downes.
At Georgia Tech, Potter has achieved similar results, getting his mobile robot to avoid obstacles 90 per cent of the time. He is hoping the research will help doctors to find ways to retrain or bypass malfunctioning neuronal circuits in people with epilepsy, and he is also starting work on Alzheimer's.
The first step towards this, though, is to find a way to train the neurons into a more permanent state of reacting to sensor inputs at the right times. In a paper to be published in the Journal of Neural Engineering, Potter describes a novel training system for these mini brains.
What he has found is that a sequence of electric pulses applied to up to six electrodes on an MEA act as a kind of "mode switch" for the culture, changing its behaviour from being good at, say, steering a robot in a straight line to manoeuvring to avoid an obstacle. But because all cultures are different, he doesn't know which pulse sequences will work best for each of them. So he randomly generates 100 different sequences - called pattern training stimuli - for each culture and lets a computer work out which ones produce the best neural connections to make a virtual robot move in a desired direction.
"A sequence of electric pulses can make the brain culture change the robot's behaviour"
After the selected stimuli have been applied a few times, certain behaviours become embedded in the culture for some hours. In other words, the culture has been taught what to do. "It's like training an animal to do something by gradual increments," Potter says.
The Reading team are now planning to study whether particular parts of the culture, rather than all of it, can be more useful for performing certain tasks. They also plan to study whether the culture should be embodied in a robot early on. At the moment, they wait three to five weeks until a culture is mature before applying any sensory input. This might amount to trying to get a sensory-deprived "insane" culture to learn, says Whalley.
This work will hopefully contribute to our knowledge of how brains work, but its potential should not be exaggerated, says Potter. "This system is a model. Everything it does is merely similar to what goes on in a brain, it's not really the same thing. We can learn about the brain - but it may mislead us."
Warwick agrees, but believes it will be useful. "If this kind of work can make a 1 per cent difference to the life of an Alzheimer's patient it will be worth it," he says.
The biggest complaint we hear from homeowners who are considering rooftop solar systems is the lack of information: How much will it cost; how long until it pays off; who’s the best local installer? A new site that launched this morning, is looking to help answer all of those queries using satellite data and a hands-on web site RoofRay.com
The creator of RoofRay, former dotcom entrepreneur Chris Bura, says his site is like Zillow meets Lending Tree for residential solar. Basically it’s a solar clearinghouse that uses Google satellite data and info from the National Renewable Energy Labs to help users make good decisions about what sort of system to buy.
Here’s how it works: enter an address, pull up the satellite image of the chosen building’s rooftop and then using the RoofRay tool based on Google maps, draw your solar arrays (see image below and YouTube video below the jump). Data on square footage of the system, slope of the roof, power per square foot and total peak power all show up in a chart, and the info displayed depends on how big you’ve drawn your system.
After drawing the panels you can dive into metrics based on the size and location of your solar system, including projected performance, financial analysis, average monthly utility bill after solar is added, total cost summary and, our favorite, time until the system pays for itself. (Update: Currently the site only has California utility rates, but Bura says he is adding in other states soon). When Bura walked us through the site, we made our roof top solar system quite massive and discovered it would be a good decade until it would break even.
Overall the system gives users as much detailed info as they’d ever want about a system. (Solar geeks, you’ll be in heaven.) Though, all that information could also be a drawback; a simpler option for users that don’t want to spend so much hands-on drawing time could make it a lot more user-friendly. We’re also not sure how close the projections are to how the solar system will actually work in real life, but users with existing solar systems, test it out and let us know.
The biggest potential of the site for the user could be the ability to test out how good a home’s solar potential is before buying it. (That’s where the Zillow comparison really comes into play.) There’s also a search function to be able to find solar systems on buildings in your area, so you can see which installers your neighbors have been signing up with.
Bura spent under $50,000 over the last 6 months building out the site with the help of just one engineer. He plans to raise funding, incorporate the company, and hire a co-founder and 2 developers to build out the site even more. The site is free to use and Bura says his business model is a combo of AdSense ads and potential partnerships with solar installers — we could see the site as a potentially good lead generator. Check out the system and give Bura some feedback; he’s currently working on validation testing.
Yahoo has just launched their entry into the growing world of "track your location" sites with the release of Fire Eagle.
The basic idea behind Fire Eagle is to become the link between your location and the services that you want to give your location to. You can feed your location to Fire Eagle from your GPS unit, cell phone, laptop, etc, then their applications can use it for whatever task you give them permission for.
Even though it has just launched, there are a large number of sites already using it, many of which tie into Google Maps. Google Maps Mania summarizes six of them, and others include major players such as Dash and Brightkite. There's even a plug-in available for Movable Type, which powers this blog. Wouldn't it be neat to see where Frank is right now?
I think the key to an application like this will be the mobile offerings they unveil. For example, the iPhone already has a slew of location-aware apps, none of which (as far as I know) feed data directly back into Fire Eagle. A free Fire Eagle app on the iPhone would provide a quick way for a few million more users to update their location.
All in all, it seems like a solid entry for Yahoo. The reviews around the web (TechCrunch, ReadWriteWeb, Mashable, etc) have been quite positive. If you are a heavy user of location-aware services, I can see this being a great tool. If you're not, though, will it be enough to get you going?
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