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Wednesday, August 5, 2015

Popular Science- Top Stories

LEXUS UNVEILS ITS WORKING HOVERBOARD

AT THE ONLY SKATEPARK WHERE IT WORKS
  
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Lexus Hoverboard And Rider
Lexus Hoverboard And Rider
Screenshot by author, from YouTube
Lexus just unveiled what is by all appearances a working hoverboard. This concept was teased about way back in June. Every story about it comes with an obligatory reference to Back To The Future Part II, that 1989 film set in the distant and far-off future of 2015, which featured an iconic hoverboard chase scene. Here’s that hoverboard in action:
Later in the video, which is best thought of as a weird, high-concept advertisement, the hoverboard literally flies over a Lexus. Check that out:
So how does the hoverboard even work? Hoverboards have been faked before, but what Lexus is doing isn’t exactly a lie or a hoax. They made a real, working hoverboard, and that’s what’s on display here. It’s just an incomplete truth. Lexus also made a skatepark with magnetic rails buried underneath, which makes the whole thing possible. The mechanism is based on the concept that when magnets have opposite poles, they repel each other and force a space between them.
To their credit, in the “making of” video about the hoverboard, Lexus shows the magnetic rail, and the 403-day-long design process it took to make the board and the park work. This wasn’t new science: as Brian Fung at the Washington Post notes, “ this technology has actually been around for years. It's what powers maglev trains. Lexus just shrunk it down to the size of a skateboard and buried the rail.”
There is art in hiding that all behind the curtain. Watch the "making of" video, featuring hoverboard pilot and pro skateboarder Ross McGouran, below:
  
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SEE THE WORLD THROUGH BIONIC EYES WITH THIS INCREDIBLE SIMULATION

BEHIND BIONIC EYES
  
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New visual simulations give us a glimpse of what it might look like to see the world through bionic eyes.
Since the FDA’s approval of the world’s first bionic eye system, the Argus II, more and more people who were once blind can now see (more than 80 by March 2014, according to a study in Neuroscience Letters). Although researchers estimated that the vision would be close to a grainy black and white film with a visual acuity of 20/1260, as opposed to general healthy vision of 20/20, there wasn’t a very robust model to back this up. In a study published in Philosophical Transactions B researchers have created realistic video simulations of what restored sight might look like.
Retinal cells in our eyes called rods and cones covert light into electrical impulses that are sent to the brain. The loss of these cells through diseases such as macular degeneration is one of the main causes of vision loss. Two of the most promising vision restoration devices is electrical prosthesis and optogenetics.
Someone may undergo an very invasive procedure and their vision isn’t what they expected to get
The Argus II bionic eye system is the major electrical prosthesis device on the market. It uses a digital camera mounted to a pair of eyeglasses that act as the eye’s rods and cones to wirelessly sends visual data to a computer chip implanted on the side of the eye. This chip then activates a small array of electrodes implanted in the retina that stimulates retinal cells to convert that data into vision.
Argus II Retinal Prosthesis System
YouTube/ Screenshot
This stimulation may not be able to give full color vision, but it can show light and dark contrast, which is enough to begin to perceive objects in space. Optogenetics, on the other hand, is where proteins are inserted into the surviving retinal cells to make them more light-sensitive, essentially forcing them to do the job of the missing rods and cones. However, this technology has yet to be implanted in humans.
The team at University of Washington used data from optogenetics research as well as predictions based on the performance of patients who had received electrical prosthesis to create more accurate representations of restored sight. These new models show the potential distortions and difficulties that those who receive either the electrical prosthesis or optogenetics might have.
These things should come with a safety warning: fast moving objects may disappear entirely
There are around 20 different retinal cell types that send different kinds of visual information to the brain, such as where edges are on objects or light or dark spots. Since electrical prosthesis stimulates all of these cells broadly, it can lead to issues such as a fuzzy or an overall blurry image.
“If you play a movie on all of these cells they’d all have very different firing patterns, but when you blast them with implants they are all forced to dance the same dance,” says co-author of the study Ione Fine.
In optogenetics only one or two types of retinal cells are stimulated, which gives the image a strange edgy quality. Fast-motion object also streak and disappear since the cells can’t keep up temporally.
“These things should come with a safety warning: fast moving objects may disappear entirely,” says Fine.
Previous simulations to show what restored vision might look like used a “scoreboard model,” which is grid system where each retinal electrode produces a collection of dots. This shows the vision as a slightly overexposed greyscale image. However, patients performance never matched what the scoreboard model predicted, showing that it has not been an accurate representation of restored vision.
Different Vision Simulation Models
University of Washington
The image on the far left is a visualization of the scoreboard model, the center image is how one might see with electric prosthesis, and the far right image is how one might see with optogenetics.
Since bionic eye implants are extremely costly, these realistic simulations can help patients and their families to decide whether it is worth spending the money on the retinal implants, as well as go through all of the long surgeries required. In 2013 the Argus II costed about $100,000.
“I think the scoreboard model is very dangerous,” says Fine. “Someone may undergo an very invasive procedure and their vision isn’t what they expected to get.”
These simulations can also help researchers to better improve future implants.
“We can pin point very clearly what problems these are going to cause and how important they are, and what is more or less important to research.”
  

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