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Powered Prosthetic Legs Work Better by Tracking EMG

Powered prosthetic legs work better when guided by electrical signals generated by the muscles, says a report published today in the Journal of the American Medical Association (JAMA). The findings suggest that bionic legs that rely on mechanical sensors to control movements would be greatly improved by the inclusion of electromyographic (EMG) data and the algorithms that interpret them.

In the study, teams from the Rehabilitation Institute of Chicago and Northwestern University tried out their system on seven people with above-knee amputations. Each participant was outfitted with 9 EMG sensors on their thighs and hips that were connected to a computer. The participants wore a prototype knee-ankle prosthesis powered by 13 mechanical sensors that measured inertia, load, position, angle, acceleration, velocity and torque of the knee and ankle joints. The prosthesis was developed by Michael Goldfarb, a mechanical engineering professor at Vanderbilt University.

The participants were asked to traverse varying terrain—up ramps, stairs, and across level ground. The prostheses relying on the mechanical sensors alone made errors 14.1 percent of the time. But when the EMG data was incorporated, the prostheses made errors only 7.9 percent of the time—or about half as often.

“That’s a lot,” says Levi Hargrove, a research scientist at the Center for Bionic Medicine at the Rehabilitation Institute of Chicago, who led the study. The seven participants were not told when the EMG data was being used, but “every subject figured it out,” said Hargrove. “At the end of the experiment, we would ask: ‘Which of the two conditions did you prefer?’ And they chose the one that used the EMG signals every time.” 

The advance is good news for people with above-knee amputations. Designing prostheses for these kinds of amputations is complex because they require precise coordination of knee and ankle movements. Particularly tricky is transitioning from one type of walking to another—like from walking on flat ground to climbing stairs.

There are only two powered leg prostheses on the market. One, which provides movement in just the knee joint, is made by an Icelandic company called Ossur. The other, called Biom, has a moving ankle; it was developed by Hugh Herr’s group at MIT. Prosthetics that combine powered knee and ankle movement are all still in the prototype stage.

A problem with these mechanical prototypes is that their designs don’t offer the flexibility necessary to accommodate different gaits. The user has to stop moving and make some kind of exaggerated body motion, or use a remote control to tell the leg what to do next—a problem that is frequently awkward and potentially dangerous. 

Hargrove’s team aims to make walking smoother and safer for people with prosthetic legs. “We want them to be able to approach and walk up stairs the same way you and I would,” says Hargrove. 

Arm prostheses are much more advanced than those for the legs. The “Luke Arm” developed by the DEKA Research and Development Corp, for example, harnesses EMG data from the amputee’s remaining arm muscles and interprets them to allow the prosthetic limb carry out multiple, simultaneous movements in the wrist and fingers that allow pinching or gripping. The device received FDA approval last year. Hargrove and his colleagues helped develop the system, and have since commercialized algorithms that can control the Luke Arm or any other arm prothesis that relies on EMG pattern recognition. 

But systems for the leg—particularly for combined knee-ankle devices—have remained elusive. Why the difference? Arms have been a clinical focus for longer than legs. Plus, technological challenges—developing motors and actuators that are strong enough, light enough, and efficient enough to carry people throughout the day without having to recharge batteries—have been difficult to overcome. But that is changing. “All of these innovations are coming together to make these categories of devices available,” says Hargrove. “So now we need to learn to control them as best we can.”

Hargrove and his team, in a collaboration with Vanderbilt and the U.S. Army, are now testing the systems on 15 participants in home settings. “That’s the real test,” says Hargrove. “We’re trying to understand if this is useful for people in the real world.”

Fraunhofer Optics Could Make Augmented Reality Specs Thinner

The list of companies with an interest in augmented reality eyewear has grown long over the years and includes some of the biggest names: Microsoft, Google, and Sony. However, consumer acceptance has been lackluster, in part because these specs are still a bit bulky.

Researchers led by Peter Schreiber at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena, Germany, say they’ve created demonstration models of  data glasses that would be much smaller and less obtrusive than the specs available now.

The key to their design is the use of a glass waveguide for light, both for the transmission and display of images.  "We have a very slim design for the eye-piece optics, which fits very well with the geometry of a wave guide," says Schreiber. A simple, elongated rectangular sheet of glass serves both as a wave guide and as the support for a small, transparent display of 8 by 15 millimeters near the eye.

A two-megapixel microdisplay produces the image at one end of the glass sheet. This image is coupled into the glass sheet by a diffraction grating—a thin microlattice deposited on the glass waveguide as a thin, transparent plastic film on the glass.  This image travels through the glass sheet and is coupled out of the wave guide at the other end close to the eye of the user by a similar microlattice.  Held close to the eye it can be viewed via an array of one-mm microlenses.

Unfortunately, using a waveguide for transmitting the image limits its definition on the display to about 800 x 600 pixels. "We have a very slim design, and we pay for this slimness in terms of projected pixels," says Schreiber.  But this would not drastically limit the application of the specs, he claims.  "If you want to use a simple navigation system, which only says, '500 meters to the right,' or …. 'there is a call on your smartphone,' or for simple graphics in a repair manual, then it will work well." 

Up to now the researchers have produced two demonstration prototypes of their data glasses. One is a real near-to-eye display with a micro imager, but it isn’t see-through. The other system cannot display moving images, but is see-through, says Schreiber. "What we have to do in the future is to put both systems together, with a real micro imager and a waveguide for the see-through option,"he says.

An additional benefit of the Fraunhofer system is that by manipulating the images—image processing—one can correct for a user’s farsightedness. Your smartphone is connected wirelessly to your display, and you will have a smartphone app that will allow you to enter your degree of vision defect, such as +1 or +2, says Schreiber. The smartphone will then process the images, allowing you to see a sharp display, says Schreiber.  He argues that moving most of the image processing power and operating software to a smartphone allows a more compact structure for the data glasses, and a longer battery life.  

The technology they are developing might also be of use in several optical instruments, such as microscopes and micromanipulators, where transparent displays could be used for placing cross hairs or a controllable cursor in the view. 

 "For future optical solutions, we are now looking for partners, like startups, to develop products with them," says Schreiber.

Fail: Computerized Clinical Decision Support Systems for Medical Imaging

Computerized systems that help physicians make clinical decisions fail two-thirds of the time, according to a study published today in the Journal of the American Medical Association (JAMA). With the use of such systems expanding—and becoming mandatory in some settings—developers must work quickly to fix the programs and their algorithms, the authors said. The two-year study, which is the largest of its kind, involved over 3,300 physicians. 

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Green Microchips Created on Cellulose Nanofibril Paper

In September 2007, while leafing through his copy of IEEE Spectrum, Zhenqiang "Jack" Ma, an engineer at the University of Wisconsin-Madison whose research focus is microwave electronics, came across a news item that left him baffled: “I was shocked by the number of cell phones that are discarded daily in the U.S. and that are still in working order—426,000 per day. That is a huge number, and as a researcher, I was concerned,” he says. And rightly so; each cell phone contains chips made of poisonous gallium arsenide (GaAs).

In the 26 May issue of Nature Communications, Ma and his colleague, materials scientist Shaoqin “Sarah” Gong, plus collaborators at UW-Madison and the Madison-based U.S. Dept. of Agriculture Forest Products Laboratory (FPL) published research describing a technique for making biodegradable semiconductor chips out of wood. What’s more, they demonstrated that microwave transmitter and receiver chips made this way perform as well as their silicon or GaAs counterparts. “Actually, our work was inspired by the IEEE Spectrum article,” says Ma.

Unlike the silicon, GaAS, and petroleum-based plastic substrates that are used in electronics—and are not biodgradable—the substrate for Ma and company’s "green" chips is made of a type of paper. But unlike paper, which typically consists of wood fibers 10 micrometers thick and bigger—making it rough and fairly easy to tear, they used much smaller fibers. “If you chop down the wood into nanosize fibers, you find that the fibers are single crystals. If you put this material together to make a substrate, it becomes very strong—stronger than the paper we use,” says Ma. “It also becomes transparent and has low RF energy loss," he adds. The cellulose nanofibril (CNF) “paper” they used is about 200 micrometers thick. Although the researchers coated it with a thin epoxy layer to protect it from moisture, this does not affect its biodegradability. "If we put it in a fungus environment, the fungus can still eat it," says the Wisconsin researcher.

To create the green chips, the researchers started out with silicon or GaAs devices sitting atop substrates made of the same material. Then they released the circuits from their original substrates and transfer-printed them onto the nanofibril substrates. Using this technique, the researchers created several microwave GaAs devices, such as arrays of GaInP/GaAs heterojunction bipolar transistors, as well as circuits containing capacitors, RF inductors and Schottky diodes.  The performance of these flexible devices is exactly the same as that of rigid circuits, reports Ma.

The group also demonstrated several silicon-based digital logic circuits on paper substrates. However, these substrates may have a wider range of applications. Nanofibril films may be used in photovoltaic cells and also in displays because they have better light-transmission properties than glass, says Ma.

Using paper substrates would allow a reduction in the amount of GaAs used in chips by a factor of 3000, which would make chips conform to the pollution standards for arsenic set by the U.S. Environmental Protection Agency. Additionally, this technique would help cut costs, reducing the amount of expensive materials, such as gallium arsenide and highly purified silicon, that are packed into electronic gadgets.

"What we are looking at are future applications,” says Ma.  The paper includes a market survey comparing today's production of rigid electronics with the projected flexible electronics production. The volume of flexible electronics is expected to largely exceed rigid electronics. 

CESAsia 2015: Stephen's Show Floor Sightings, Part II

The Arduboy


A runaway success on Kickstarter, the Arduboy is a hackable-by-design, credit-card-size system for classic arcade-style games. It’s powered by the same Atmel chip that runs the Arduino. Unlike some Kickstarter projects that have struggled to cross over from prototype to production, the Arduboy is already lining up its ducks with Chinese manufacturers in Shenzhen. If you want to get one, the Kickstarter campaign is still active, US $30 will get you early delivery, scheduled to happen in October.

The WenPod

Behold! The next generation selfie stick! Similar to the kind of gyroscopic stabilization rigs available for video cameras, the WenPod X1 can keep your camera pointing in your direction, even as the selfie stick it’s attached to moves around. It will be available in the United States in June for US $160. 

IBM Watson's Recent Acquisitions Might Make It a Knowledge Machine You Can Actually Use

IBM Watson has been buying some interesting companies and technologies lately:

  • Cognea, a company that had developed a “conversational artificial intelligence program” meant to provide more natural interactions than current voice-controlled assistants like Siri and Cortana.
  • AlchemyAPI, a company that provides natural language processing and image recognition as an on-demand service.
  • Blekko, an alternative search engine known (as much as it was) for its classification and filtering of results

Looking at these capabilities all together provides some hints about Watson’s current weaknesses as well as IBM’s long-term plan for the system. All three are customer-facing technologies which provide different ways to interact with Watson’s collection of data and analytics capabilities.

In January 2014, IBM set aside US$ 1 billion to turn Watson into an actual business, because it’s generally been better at generating publicity than revenue. Despite all the potential that Watson the-general-purpose-AI might have, it’s still a bit unclear what Watson the business will do. For a large company that is having difficulty commercializing their own internal research, buying up smaller companies that already have users or customers is a common approach (Marissa Mayer’s buying spree at Yahoo comes to mind). 

“IBM is notorious for producing a lot of 80-percent solutions,” says Seth Grimes, an industry analyst and consultant who organizes the Sentiment Analysis Symposium. “The technology is there, but you can't just open up a box, download the software, and have it run. I see Watson in that situation right now.” That’s in contrast with AlchemyAPI, which Grimes describes as a “market tested” platform that’s already had cutomers for years. 

In addition to its web interface, AlchemyAPI also provides software development kits to support text analysis and image recognition in several programming languages. Watson does not have that kind of interface available, says Grimes. “They could build one, but for a company like IBM, it's faster, cheaper, and perhaps more feasible to buy it than to try to productize something out of their research organization,” he adds.

But for Watson to live up to IBM’s hopes, it will also have to be usable for non-developers. Cognea’s technologoy might be a step in that direction. Apple and IBM already had a deal to provide Siri with Watson data and analytics, but it’s clear that digital assistants have plenty of room for improvement. Current question answering systems (including the ubiquitous Google search) don’t have much context or state, says Grimes—each question is answered independently. But IBM aspires for Watson to have an interactive learning experience, so Cognea’s conversational model might help users give Watson better contextualized and refined questions.

Finally, the purchase of a search engine might reignite the idea that Watson will be a Google search competitor. “IBM aspires to assist knowledge workers,” says Grimes, “and Google is arguably in that same field.” After all, Google search results have evolved beyond simply listing links to web pages—the Google Now app on Android devices can provide all sorts of contextual information without ever opening a browser. 

But the two companies have very different ideas about how to make money with such knowledge. As Chuck McMannis, Blekko’s VP of Engineering explained it in his comment on Hacker News:

Blekko's key mission has always been to try to find the needles in this exponentially growing pile of hay. And it is something that the folks at Watson really liked about our technology when we first met at their outreach program to connect with startups. That is what lead to their asking us to join them, and no, they weren't particularly interested in the stuff we had done to provide more topical advertising signals.

CESAsia 2015: China’s Maker Scene Is Exploding

On the last day of CESAsia, nervous representatives from maker spaces and universities located in Shanghai and surrounding cities trooped on stage to make presentations to a panel of judges. It was a scene that would be familiar to many makers and hobbyists in other countries, but it was something new to China, as it was the country’s first maker contest. But it won’t be the last, if the rapid growth in the number of maker spaces there is any indication. This growth is now being officially supported by the Chinese Ministry of Industry and Information Technology (MIIT).

“Domestic maker spaces started in 2010, and it was a very niche activity,” said Rocky Zheng, head of the Nanjing Maker Space, through a translator before the judging began. “Until 2013, China had only 15 spaces, then it began booming. By April 2014, there were over 100 spaces.”  

Projects presented during the event included: a headset for bathing dry eyeballs in vapor containing traditional Chinese medicines; a device for harvesting energy from straphangers being swung back and forth as buses and subway trains lurch along their routes; a system that would allow a person to have their text messages appear at the bottom of a television screen; potters clay that had been reformulated so it can be extruded from a modified 3-D printer capable of rendering complex ceramic designs; and an electronic lock that was opened by coded light signals from a smartphone app. The winner was a team from Shanghai that developed a system for warning a driver when he or she is straying out of their lane.

The MIIT has started supporting maker spaces and small tech startups in part by creating an online platform for makers to exchange information about projects. It has also begun raising funds via crowd funding to defray the costs of commercializing projects. The ultimate goal is boosting China’s ability to be technologically creative. Some of the speakers at the contest representing the government seemed to consider makers as nascent business entrepreneurs, and maker spaces as commercial incubators that would feed directly into industry. This was reflected in a second round of the contest, in which teams from small—and not-so-small—companies presented new product ideas such as an automated frying pan. We also saw smart systems for reducing office energy use—more the kind of thing that elsewhere would be seen at a Y Combinator-style event rather than a maker contest.

But several speakers were quick to make the point that while commercial products can come out of maker spaces, it would be a mistake to view them, and the people working in them, so narrowly: “We try to best turn our creativity and hobbies into reality. We may be able to commercialize in some areas, but in others we are simply playful in our effort. Makers go beyond the scope of entrepreneurs in our effort,” says Nanjing Maker Space’s Zheng.

Currently, the goal is to create maker spaces in the provinces, spreading them out from their current concentration in and near cities such as Beijing, Shanghai, and Shenzhou. If this can be done with the same maker spirit espoused by Zheng, China could indeed be seeding a creative tech renaissance.

CESAsia 2015: China’s Consumer Tech Market Moves Upscale

We take it as a matter of course that China will continue cranking out much of the world’s consumer electronics. But because these products were often not geared to Chinese citizens, their tastes were mostly overlooked. But domestic demand has been rising dramatically in recent years. And the sheer size of the Chinese retail market is changing the game.

Tomorrow, I’ll have a report about the results of some recent data obtained by the Consumer Electronics Association about how individual Chinese people in different cities make decisions about product purchases. But today I’m looking at the macro drivers of China’s consumer tech market, with some highlights from a presentation from Alfred Zhou of market research firm GFK.

The biggest driver has been the continued surge in China’s middle class. Zhou showed a projection indicating that by 2030, 66 percent of the world’s middle class will live in Asia (with Europe accounting for 14 percent, and the United States and Canada just 7 percent).

In earlier years, it might have been enough for Chinese consumers to get just a basic product—that first TV or cellphone. But now China is experiencing market maturation and saturation for the first time. Consequently, the mid-to-high-end market is where much of the growth is occurring. And an increasing portion of the profit in China’s consumer tech is found not in selling products, but in offering services that accompany those items (think streaming TV rather than the TV itself). Niche products also offer opportunities for growth in otherwise mature product categories—for example, notebooks optimized for gaming have captured 10 percent of the Chinese PC market in the past two years.

A similar dynamic is driving the adoption of various technology upgrades as well. Zhou points out, for example, that it took 20 years to fully roll out 2G cellular service, in China, then five more years for 3G. By contrast, 4G should reach 80 percent penetration in just two years.

An important wrinkle to consider when thinking about how China’s market is evolving is the different “tiers” represented by the nation’s cities. There are no formal definitions, but generally speaking, there are just four or five cities considered to be tier-one mega metropolises. Among these are Beijing and Shanghai. There are dozens of tier-two cities, and many hundreds of tier-three, -four or -five cities. But bear in mind a tier-three city can easily have a population of more than a million people. The aggregated wants and needs of these lower tier cities are going to be much bigger drivers of what products and services will succeed in China than what’s going on in the high-profile tier one megacities.

CESAsia 2015: Stephen's Show Floor Sightings

Roobo Pudding


This is probably the world’s most adorable security camera. Like a Dropcam, the Pudding allows you to monitor your home via a smartphone app, and even speak to people through a microphone and speaker set up in the camera. Unlike a Dropcam however, Pudding will accept voice commands to do things like play music for you, while conveying various “emotions” using its LED “eyes.” It also comes with a wireless sensor about the size of an overcoat button that can be placed just about anywhere in the house and used to detect the opening of doors or windows out of Pudding’s line of sight. Pudding will go on sale in China in September for a little under US $50.

Fastwheel Ring


The Ring is the latest entry in Fastwheel’s lines of electric monocycles designed to be ridden by standing on their footrests (think of a Segway without all the extravagant messing about with a handle and a second wheel). When I first saw Fastwheel’s earlier product—the Eva—at CES Las Vegas, it struck me as something of a flash-in-the-pan stunt product that few people would actually buy. But exploring outside of CESAsia, I’ve seen similar monocycles for sale in several stores in one of Shanghai’s sprawling electronics and fashion markets, and I did spot a person whizzing down the road through scooter traffic riding one. The company says it’s been making domestic sales in China and finding customers in Spain, Korea, and Thailand, so it may be only a matter of time before it goes global. The Ring has yet to be released, so there’s no official price, but the Fastwheel Eva’s Pro and Super models clock in at US $280 and $330 respectively, so the Ring will probably be somewhere around that range.

Sleep Shepherd


This headband doesn’t just track sleep—the manufacturer claims it can actively relax a wearer’s mental state and help them nod off. A set of three electrodes—made of conductive fabric—on the inside of the band monitors brainwaves. This information is used to create slightly different tones in a pair of built in headphones. The idea is that adjusting the frequency difference between the tones can stimulate longer, more relaxed brainwaves. As the wearer’s brainwaves adapt to one set of tones, the electrodes sense it and change the tones with the aim of lengthening the brainwaves even more. This goes on until a state of sleep has been reached. For US $150 you can see if it works for you.

Aquatic Speakers


Like smartwatches and fitness trackers, floating waterproof wireless music speakers are apparently a distinct product category now, as demonstrated by the fact I ran across three different companies making them. They all have somewhat similar specs and prices; representative of the group are the brightly-colored, lozenge shaped speakers from Zupool [above], which will be released in the last quarter of 2015 and will cost about US $80 retail.



This is a prototype of a headset and controller designed for virtual reality software with adult content. (The software runs on a smartphone that fits into the case and acts as the device’s display.) The creators hope to bring it into production by launching an Indiegogo campaign later this year. But be warned: This is not the beginning of a richly textured voyage into a new form of erotica. Based on the demo material, it’s solely and crudely aimed at what a heterosexual teenage boy might find intriguing.

Pao Smile Trainer


Okay, this one isn’t remotely electrotech, but the packaging—featuring an oh-so-earnest model demonstrating how to use it to improve one’s “facial fitness”—made me crack up on the show floor. The idea is that you hold the Pao (from Hong Kong company Shlab) between your teeth and then bob your head up and down for 30 seconds, two times a day. Different weights can used to increase resistance during the bobbing. The result, apparently, is a youthful smile for a mere US $125. 



The fact that Twitter had a booth, in a country where the entire population of 1.3 billion can’t officially access the social media service, perplexed me at first. But it turns out that while Chinese companies can’t use Twitter to speak to their domestic audience, they will happily buy advertising on it to reach the international market.

CESAsia 2015: Batteries Are Strangling Mobile Electronics

On the second day of CESAsia, Tom Coughlin of the IEEE Consumer Electronics Society painted a grim picture of conventional mobile power technology. Based on trends to date, Coughlin estimates that the energy density of batteries is doubling only every 10 years, while Moore’s Law doubles the transistor count for CPUs every 18 months or so.

The result is an widening mismatch between what we’d like to do with mobile devices and what we can do. For example, according to Coughlin’s analysis, getting a smartphone’s battery to last a full week between charges, the way the ones powering old cellphones used to do, would require between 26 and 104 times the amount of energy typically stored by the batteries in today’s handsets. At the current lethargic pace of battery technology development, it would take decades to get a battery with enough juice to be an adequate match for the phone that sits in your pocket or purse right now, waiting for a recharge.

And that’s not even accounting for some of the power-hungry things we like to try with our phones, from computational imaging that could make the image sensors on today’s phones look like pinhole cameras, or continuous life logging.

In a valiant attempt to play catch-up, the Consumer Electronics society is pushing a new initiative in hopes of rapidly improving the power sources available for mobile devices: the Safe Advanced Mobile Power initiative.

The technical requirements for the ideal future power source the society envisions boil to these: In addition to providing enough energy, it has to be cost efficient, scaling with manufacturing volume so that by the time we’re knocking out this source by the hundred million, the unit cost should be no more than around US $20. It also has to be safe, and not likely to result in deaths either among users or among those employed in extracting and processing the raw materials. That’s a tall order, but it’s definitely worth a shot.

It’s entirely possible that battery technology will never get to where we need it to be for mobile devices. With that in mind, there are three alternatives to batteries that may someday usurp their dominance. The first is fuel cells, which various people have been trying to incorporate into things like laptops for a while now. The second is energy harvesting, sipping power from mechanical or thermal sources of energy in the environment. Last but not least is wireless power, whereby energy would be transmitted to mobile devices through the air. Recently, wireless has become increasingly popular as a way to recharge the batteries in mobile devices. But if wireless charging’s market share is to ever reach parity with that of batteries, improvements aimed at making it more useful will have to be made. More consumers will clamor for it once the range over which it works is extended and the amount of energy that can be transmitted over the air is increased.

If we can’t solve this power problem, then mobile devices are always going to be pale shadows of what they could really be.


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