How can help Smartphone ‘scores’ to doctors track severity of Parkinson’s disease symptoms

Parkinson's disease, a progressive brain disorder, is often tough to treat effectively because symptoms, such as tremors and walking difficulties, can vary dramatically over a period of days, or even hours.

To address this challenge, Johns Hopkins University computer scientists, working with an interdisciplinary team of experts from two other institutions, have developed a new approach that uses sensors on a smartphone to generate a score that reliably reflects symptom severity in patients with Parkinson's disease.

In a study published recently online in the journal JAMA Neurology, researchers from Johns Hopkins' Whiting School of Engineering, the University of Rochester Medical Center, and Aston University in the United Kingdom reported that the severity of symptoms among Parkinson's patients seen by neurologists aligned closely with those generated by their smartphone app.

Typically, patients with Parkinson's disease are evaluated by medical specialists during three or four clinic visits annually, with subjective assessments capturing only a brief snapshot of a patient's fluctuating symptoms. In their homes, patients may also be asked to fill out a cumbersome 24-hour "motor diary" in which they keep a written record of their mobility, involuntary twisting movements and other Parkinson's symptoms. The doctor then uses this self-reported or imprecise data to guide treatment.

In the new study, the researchers say patients could use a smartphone app to objectively monitor symptoms in the home and share this data to help doctors fine-tune their treatment.

E. Ray Dorsey, a University of Rochester Medical Center neurologist and a co-author of the research paper, said he welcomes the validation of Parkinson's patient severity scores produced by the smartphone tests.

"If you think about it, it sounds crazy," he said, "but until these types of studies, we had very limited data on how these people function on Saturdays and Sundays because patients don't come to the clinic on Saturdays or Sundays. We also had very limited data about how people with Parkinson's do at two o'clock in the morning or 11 o'clock at night because, unless they're hospitalized, they're generally not being seen in clinics at those times."

About six years ago, while doing medical research at Johns Hopkins, Dorsey was introduced to Suchi Saria, an assistant professor of computer science at the university. Saria, the corresponding author of the study and an expert in a computing technique called machine learning, had been using it to extract useful information from health-related data that was routinely being collected at hospitals. The two researchers, along with some of Saria's students, teamed up to find a way to monitor the health of Parkinson's patients as easily as people with diabetes can check their glucose levels with a pinprick blood test.

The team members knew that neurologists evaluated their Parkinson's patients by gathering information about how they moved, spoke and completed certain daily tasks. "Can we do this with a cellphone?" Saria wondered at the time. "We asked, 'What are the tricks we can use to make that happen?' "

Using existing smartphone components such as its microphone, touch screen and accelerometer, the team members devised five simple tasks involving voice sensing, finger tapping, gait measurement, balance and reaction time. They turned this into a Smartphone app called 'HopkinsPD.' Next, using a machine learning technique that the team devised, they were able to convert the data collected with these tests and turn that into an objective Parkinson's disease severity score—a score that better reflected the overall severity of patients' symptoms and how well they were responding to medication.

The researchers say this smartphone evaluation should be particularly useful because it does not rely on the subjective observations of a medical staff member. Moreover, it can be administered any time or day in a clinic or within the patient's home, where the patient is less likely to be as nervous as in a medical setting.

"The day-to-day variability of Parkinson's symptoms is so high," Saria said. "If you happen to measure a patient at 5 p.m. today and then three months later, again at 5 p.m., how do you know that you didn't catch him at a good time the first time and at a bad time the second time?"

Collecting more frequent smartphone test data in a medical setting as well as in the home, could give doctors a clearer picture of their patients' overall heath and how well their medications are working, Saria and her colleagues suggested.

Summarizing the importance of their finding in the JAMA Neurology report, the researchers said, "A smartphone-derived severity score for Parkinson's disease is feasible and provides an objective measure of motor symptoms inside and outside the clinic that could be valuable for clinical care and therapeutic development."

Patients in the research project used Android smartphones to download the software, available through the Parkinson's Voice Initiative website. The team has now partnered with Apple and Sage Bionetworks to develop mPower, an iPhone version that is available at Apple's App Store.

The study's three co-lead authors included two of Saria's students from the Department of Computer Science at Johns Hopkins: doctoral candidate Andong Zhan and third-year undergraduate Srihari Mohan.

Zahn, who is from Qujing, Yunnan, in China, described the project as "a unique experience of extracting data from the physical world to a digital world and finally seeing it become meaningful clinical information."

Mohan, who is from Redmond, Washington, added, "While not all research gets integrated tangibly into people's lives, what excites me most is the potential for the methods we developed to be deployed seamlessly into a patient's lifestyle and improve the quality of care."

Scientists develop tiny tooth-mounted sensors that can track what you eat

Monitoring in real time what happens in and around our bodies can be invaluable in the context of health care or clinical studies, but not so easy to do. That could soon change thanks to new, miniaturized sensors developed by researchers at the Tufts University School of Engineering that, when mounted directly on a tooth and communicating wirelessly with a mobile device, can transmit information on glucose, salt and alcohol intake. In research to be published soon in the journal Advanced Materials, researchers note that future adaptations of these sensors could enable the detection and recording of a wide range of nutrients, chemicals and physiological states.

Previous wearable devices for monitoring dietary intake suffered from limitations such as requiring the use of a mouth guard, bulky wiring, or necessitating frequent replacement as the sensors rapidly degraded. Tufts engineers sought a more adoptable technology and developed a sensor with a mere 2mm x 2mm footprint that can flexibly conform and bond to the irregular surface of a tooth. In a similar fashion to the way a toll is collected on a highway, the sensors transmit their data wirelessly in response to an incoming radiofrequency signal.

The sensors are made up of three sandwiched layers: a central "bioresponsive" layer that absorbs the nutrient or other chemicals to be detected, and outer layers consisting of two square-shaped gold rings. Together, the three layers act like a tiny antenna, collecting and transmitting waves in the radiofrequency spectrum. As an incoming wave hits the sensor, some of it is cancelled out and the rest transmitted back, just like a patch of blue paint absorbs redder wavelengths and reflects the blue back to our eyes.

The sensor, however, can change its "color." For example, if the central layer takes on salt, or ethanol, its electrical properties will shift, causing the sensor to absorb and transmit a differentspectrum of radiofrequency waves, with varying intensity. That is how nutrients and other analytes can be detected and measured.

"In theory we can modify the bioresponsive layer in these sensors to target other chemicals - we are really limited only by our creativity," said Fiorenzo Omenetto, Ph.D., corresponding author and the Frank C. Doble Professor of Engineering at Tufts. "We have extended common RFID [radiofrequency ID] technology to a sensor package that can dynamically read and transmit information on its environment, whether it is affixed to a tooth, to skin, or any other surface."

Chinese solar boom sparks global renewables boon: 160 gigawatts

AChinese boom in solar panel installation last year helped drive global investment in renewable clean energy technology to record levels, a new study showed Tuesday.

After a dip in 2016, overall global investment in the sector rose 3.0 percent to a total $333.5 billion, offsetting falls in Japan, Germany and Britain, according to the Bloomberg New Energy Finance (BNEF) study.

That was the second best annual showing to date after $360.3 billion in 2015.

"The 2017 total is all the more remarkable when you consider that capital costs for the leading technology -– solar -– continue to fall sharply," said BNEF chief executive Jon Moore.

Solar investment came in at $160.8 billion in 2017, a rise of 18 percent despite per megawatt capital costs falling by around a quarter, with China accounting for around half the overall total at $86.5 billion—up 24 percent, the study said.

"China installed about 20 GW more solar capacity in 2017 than we forecast," said Justin Wu, BNEF head of the Asia-Pacific region, as the Chinese notably showed off the world's first photo voltaic expressway.

Investment in wind power slipped back 12 percent last year, however, to $107.2 billion after a strong rise in 2016.

Solar and wind power remain far out in front in terms of renewable energy forms ahead of the likes of biomass, geothermal and small scale hydroelectricity which each attracted less than $5 billion last year.

Well behind China, the United States landed investments of $56.9 billion—a rise even so of 1.0 percent despite an unfavorable political climate with President Donald Trump skeptical of climate change and withdrawing his country from the Paris climate agreement.

The study highlighted what it termed Washington's "less friendly tone towards renewable."

A handful of countries saw investments more than double, including Sweden to $4 billion and Australia to $9 billion.

Egypt saw a 495 percent increase to $2.6 billion while investment in the United Arab Emirates enjoyed a dizzying 23-fold rise to $2.2 billion.

Europe saw a notable decline in renewable investment to $57.4 billion, the fall-off hitting 26 percent in Germany and 56 percent for the United Kingdom on energy policy changes

Japan saw a 16 percent drop, while India was down 20 percent to $11 billion.

BNEF estimated last year saw a record 160 gigawatts of renewable power installed, not counting hydroelectricity, comprising 98 GW of solar and 56 GW of wind power.

Energy-smart technology, such as smart meters and energy storage, is also making headway, BNEF noted.

Novel semiconductor-superconductor structure features versatile gallium nitride- Heterostructure

Silicon has been the semiconductor material of choice for electronics pretty much since the transistor effect was first observed and identified nearly 80 years ago. There's a valley in California named for it, after all.

But a relatively new family of semiconductors – group III-nitrides, including gallium nitride (GaN), indium nitride and aluminum nitride – offers greater versatility than silicon with capabilities for ultrafast wireless communications, high-voltage switches and high intensity lighting and photonics.

A team led by Debdeep Jena, professor of electrical and computer engineering (ECE), and David Meyer, head of the Wide Bandgap Materials and Devices section at the Naval Research Laboratory, has successfully devised a semiconductor-superconductor crystalstructure featuring GaN grown directly onto a crystal of niobium nitride (NbN), a proven superconductor material used in quantum communications, astronomy and a host of other applications.

The group's paper, "GaN/NbN Epitaxial Semiconductor/Superconductor Heterostructures," is being published online March 8 in Nature. Former postdoctoral researcher Rusen Yan and current postdoc Guru Khalsa are co-lead authors.

Other key contributors were Grace Xing, the Richard Lundquist Sesquicentennial Professor in ECE and MSE, and David Muller, the Samuel B. Eckert Professor of Engineering in the Department of Applied and Engineering Physics.

The method for combining the two materials – molecular beam epitaxy (MBE), essentially spray painting of gallium and nitrogen atoms onto the NbN in a vacuum environment – creates an extremely clean interface and is key to the success of the novel structure.

This advance, the group says, opens up a range of possibilities that can now combine the macroscopicquantum effects of superconductors with the rich electronic and photonic properties of group III-nitride semiconductors.

"People have tried it with other semiconductors, like silicon and gallium arsenide, but I don't think anything has been as successful as what we've managed to do with GaN," said Jena, who has a dual appointment with the Department of Materials Science and Engineering (MSE).

Gallium nitride-based semiconductors have recently made major inroads in the areas of LED lighting, Blu-ray laser diodes, energy and communications. In fact, the 2014 Nobel Prize in physics was given to a trio of Japanese scientists for their invention of energy-efficient blue light-emitting diodes (LEDs) using GaN.

Technological advances – particularly the type of MBE used in this work, which was developed at the Naval Research Laboratory – has made it possible for scientists to think about semiconductor-superconductor heterostructures such as the one Jena's group has developed.

The specialized nitride MBE system includes an electron beam evaporator source, which "melts" the niobium – which has a melting point of around 4,500 degrees – but not the crucible it's in. Atoms of niobium are deposited onto a silicon carbide wafer, and the GaN semiconductor layers are then grown on top of that, also by MBE.

"This new source allowed us to overcome the temperature limitations of conventional sources, and bring high-melting-point, refractory transition metals like niobium and tantalum into the picture," Meyer said.

The team demonstrated for the first time the growth and fabrication of a semiconductor transistor switch, the prototypical gain element in electronics, directly on top of a crystalline superconductor layer. This heterostructure is a kind of "best of both worlds," Jena said, offering a method for devising quantum computation and highly secure communications systems.

"There are some things that we would love to do with quantum systems – quantum computation and cryptography, things that are not possible in classical systems," he said. "On the other hand, there are things that classical systems are much better at than quantum systems. And there is this mesozone where you can do wonderful things by mixing and matching the two."

"We think this presents a wonderful opportunity for rapid technology development of next-generation communications and computation systems," Meyer said.

Tiny, light-sensitive chips could one day restore sight to the blind-Retina

Age-related macular degeneration, a disease that slowly degrades light-sensitive cells in the retina, is the leading cause of vision loss and blindness among people 65 and older, according to the Centers for Disease Control and Prevention. Doctors can't prevent such loss of sight – but a system that replaces light-sensitive cells designed by Daniel Palanker, a professor of ophthalmology, may ease the burden.

The device – a combination of image-processing goggles and tiny silicon chips implanted in the retina– has been more than a decade in the making. Although the device's resolution is not yet where its designers hope to get it – currently the technology can only reach 20/200 vision, which is not enough to read clearly or drive safely – a five-patient feasibility study has begun in Paris, with a second planned later in the year in the Eastern United States.

"We published the first concept paper of how we would approach this 12 years ago, and now we've validated in human patients basically all the key assumptions we made on the way," said Palanker, who is also the director of the Hansen Experimental Physics Laboratory and a member of Stanford Bio-X and the Stanford Neurosciences Institute.

Too many wires

Palanker had been interested in how eyes function since his graduate studies in applied physics. Until the early 2000s, most of Palanker's research focused on the use of lasers in eye surgery.

Then he learned about artificial retinas, assistive devices intended to treat patients who have lost some of the light-sensitive cells in their retinas to diseases such asage-related macular degeneration or retinitis pigmentosa.

But artificial retinas that were then in development had a number of drawbacks. For one thing, none of them achieved decent resolution. At the time, the best artificial retina corresponded to about 20/1200 vision. In addition, most devices in the early 2000s needed many wires. Some systems implanted a camera directly into the eye, which required elaborate wiring just to power it. Other devices mounted the camera onto glasses and fed the images through a cable to an electrode array placed on the retina. All the options demanded invasive, complex surgery and long-term maintenance issues, including managing problematic cables that crossed the eye wall, sometimes affecting the remaining healthy rods and cones.

Palanker thought he could do better using a purely optical approach. As he imagined it, patients would wear special goggles that would convert ambient light into normally invisible infrared images and project those images into the eye in a manner similar to augmented-reality glasses. Photovoltaic cells – essentially tiny solar panels – implanted under the damaged parts of the retina would pick up the infrared images and convert them into electrical signals, replacing the function of damaged rods and cones.

"I thought that the eye is a beautiful optical system, where information and power can be delivered by light, and this would eliminate the need for wires and make surgery much less invasive," Palanker said. In addition, it would be easier to miniaturize the photovoltaic sensors, thus improving resolution. Palanker's device provides an added benefit as well: because the implanted sensors would only replace damaged rods and cones, patients could still see normally with the parts of their retinas that hadn't been damaged.

By 2005, Palanker and colleagues had published a plan for how their device would work, and in 2008 they won a Bio-X seed grant to begin building a device and testing this idea in rodents.

The next phase

Pixium Vision, the company that licensed the photovoltaic retinal prosthesis, or PRIMA, technology in 2013, manufactured a device for humans and got approval for clinical testing in late 2017. Clinical trials started last month, and so far three patients have been implanted with the device. Those surgeries went well, Palanker said, and patients report seeing bright white patterns in their formerly damaged areas, within the resolution limits researchers had expected. Thorough testing is now being conducted to assess the quality of this prosthetic vision, including how well patients can make out various shapes and letters.

The researchers still face important challenges – most importantl, further improving resolution. Right now, pixels in human implants are 100 micrometers in size, and tests demonstrated that 50 micrometer pixels also work well, providing spatial resolution equivalent to about 20/200 vision. Eventually, Palanker would like to get it to 20/40 – what the state requires for a driver's license – and the lab expects to publish a new design for achieving that resolution later this year, he said. The researchers are also developing better ways of processing images, so that patients can distinguish objects more easily.

"We are addressing one of the largest unmet needs in incurable blinding conditions," Palanker said. "It's very exciting."

Cheap 3-D printer as flat can produce self-folding materials

Researchers at Carnegie Mellon University have used an inexpensive 3-D printer to produce flat plastic items that, when heated, fold themselves into predetermined shapes, such as a rose, a boat or even a bunny. Lining Yao, assistant professor in the Human-Computer Interaction Institute and director of the Morphing Matter Lab, said these self-folding plastic objects represent a first step toward products such as flat-pack furniture that assume their final shapes with the help of a heat gun. Emergency shelters also might be shipped flat and fold into shape under the warmth of the sun.

Self-folding materials are quicker and cheaper to produce than solid 3-D objects, making it possible to replace noncritical parts or produce prototypes using structures that approximate the solid objects. Molds for boat hulls and other fiberglass products might be inexpensively produced using these materials.

Yao will present her group's research on this method, which she calls Thermorph, at CHI 2018, the Conference on Human Factors in Computing Systems, April 21-26 in Montreal, Canada.

Other researchers have explored self-folding materials, but typically have used exotic materials or depended on sophisticated processing techniques not widely available. Yao and her research team were able to create self-folding structure by using the least expensive type of 3-D printer—an FDM printer—and by taking advantage of warpage, a common problem with these printers.

"We wanted to see how self-assembly could be made more democratic —accessible to many users," Yao said.

FDM printers work by laying down a continuous filament of melted thermoplastic. These materials contain residual stress and, as the material cools and the stress is relieved, the thermoplastic tends to contract. This can result in warped edges and surfaces.

"People hate warpage," Yao said. "But we've taken this disadvantage and turned it to our advantage."

To create self-folding objects, she and her team precisely control this process by varying the speed at which thermoplastic material is deposited and by combining warp-prone materials with rubber-like materials that resist contracture.

The objects emerge from the 3-D printer as flat, hard plastic. When the plastic is placed in water hot enough to turn it soft and rubbery—but not hot enough to melt it—the folding process is triggered.

Though they used a 3-D printer with standard hardware, the researchers replaced the machine's open source software with their own code that automatically calculates the print speed and patterns necessary to achieve particular folding angles.

"The software is based on new curve-folding theory representing banding motions of curved area. The software based on this theory can compile any arbitrary 3-D mesh shape to an associated thermoplastic sheet in a few seconds without human intervention," said Byoungkwon An, a research affiliate in HCII.

"It's hard to imagine this being done manually," Yao said.

Though these early examples are at a desktop scale, making larger self-folding objects appears feasible.

"We believe the general algorithm and existing material systems should enable us to eventually make large, strong self-folding objects, such as chairs, boats or even satellites," said Jianzhe Gu, HCII research intern.

Leap Motion: VR fans will be able to go mobile- Combination of Software and Hardware

(Tech Xplore)—Leap Motion has announced it is bringing its technology to mobile platforms.

Nice to hear, as David Holz, co-founder and chief technology officer at Leap Motion, said it indicates "an important shift towards mobile and ubiquitous wearable displays that will eventually be as easy and casual to use as a pair of glasses."

Cherlynn Low in Engadgetreported how Leap Motion has expanded its scope to mobile devices. Simply called Mobile Platform, this is a combination of software and hardware.

Low wrote about what Leap Motion has done: (1) built a reference system of its new sensor and platform on top of a Gear VR, shipping to headset makers. (2) bringing demos of its Interaction Engine (for natural hand gestures) in this portable medium to major VR events coming up.

Fast Company described it: "a combination of hardware and software meant to make it possible to track users' hands with untethered devices."

The platform includes what TechSpot called "two miniature cameras in a small strip that can be embedded into mobile head-mounted displays, to detect finger motion."

The mobile platform is to be showcased at upcoming events, said Engadget. Low also said, "we're not expecting to see the new sensor show up in actual devices until at least a few months from now." Holz blogged that "Starting this month, we'll be demoing this system at major VR events with an enhanced version of our Interaction Engine and flagship Blocks demo."

Holz said challenges to build a tracking platform in this space were "immense."

Holz said they had to build "a whole new Leap Motion sensor with higher performance and much lower power. We needed to make the most sophisticated hand tracking software in the world run at nearly 10 times the speed all while making it smoother and more accurate than ever before."

(TechRadar said the software was made to run at nearly 10 times the speed in order to compensate for the lower processing power on smartphones.)

Holz, meanwhile, said they built it with "the absolute maximum field of view that a single sensor can support on a VR headset, which is 180×180 degrees."

Kevin Lee in TechRadar said this 180 x 180 degree field of view was "much wider than the original model's 140 x 120 field of view."

Julian Chokkattu in Digital Trends described the tracking technology in some more detail: "The tracking technology is impressive—it's able to accurately imitate intricate movements of the hand because it tracks every single joint in the hand all the way down to the elbow. The demo allowed us to create blocks with our hands, and it felt natural interacting with them. You can flick them, throw them in the air, catch them, and do just about anything you'd expect to with your hands in the physical world."

Researchers use emerging memory devices to develop electronic circuits for cyber security applications-Major Damage

While we embrace the way the Internet of Things already is making our lives more streamlined and convenient, the cybersecurity risk posed by millions of wirelessly connectedgadgets, devices and appliances remains a huge concern. Even single, targeted attacks can result in major damage; when cybercriminals control and manipulate several nodes in a network, the potential for destruction increases.

UC Santa Barbara computer science professor Dmitri Strukov is working to address the latter. He and his team are looking to put an extra layer of security on the growing number of internet- and Bluetooth-enabled devices with technology that aims to prevent cloning, the practice by which nodes in a network are replicated and then used to launch attacks from within the network. A chip that deploys ionic memristor technology, it is an analog memory hardware solution to a digital problem.

"You can think of it as a black box," said Strukov, whose new paper, "Hardware-intrinsic security primitives enabled by analogue state and nonlinear conductance variations in integrated memristors," appears on the cover of Nature Electronics. Due to its nature, the chip is physically unclonable and can thus render the device invulnerable to hijacking, counterfeiting or replication by cyber criminals.

Key to this technology is the memristor, or memory resistor—an electrical resistance switch that can "remember" its state of resistance based on its history of applied voltage and current. Not only can memristors can change their outputs in response to their histories, but each memristor, due to the physical structure of its material, also is unique in its response to applied voltage and current. Therefore, a circuit made of memristors results in a black box of sorts, as Strukov called it, with outputs extremely difficult to predict based on the inputs.

"The idea is that it's hard to predict, and because it's hard to predict, it's hard to reproduce," Strukov said. The multitude of possible inputs can result in at least as many outputs—the more memristors, the more possibilities. Running each would take more time than an attacker may reasonably have to clone one device, let alone a network of them.

The use of memristors in today's cybersecurity is especially significant in light of machine learning-enabled hacking, in which artificial intelligence technology is trained to "learn" and model inputs and outputs, then predict the next sequence based on its model. With machine learning, an attacker doesn't even need to know what exactly is occurring as the computer is trained on a series of inputs and outputs of a system.

"For instance, if you have 2 million outputs and the attacker sees 10,000 or 20,000 of these outputs, he can, based on that, train a model that can copy the system afterwards," said Hussein Nili, the paper's lead author. The memristiveblack box can circumvent this method of attack because it makes the relationship between inputs and outputs look random enough to the outside world even as the circuits' internal mechanisms are repeatable enough to be reliable.

"It has to look random, but it should also be deterministic," he said.

In addition to the variability embedded in these memristor circuits, other features include high throughput, speed and economy of energy use, making them an ideal component in the tight energy budget of the Internet of Things. Then there is the fact that this is already a semi-practical technology which can be used to both secure device identity and encrypt information.

"If we scale it a little bit further, it's going to be hardware which could be, in many metrics, the state-of-the-art," Strukov said.

As they continue to refine this technology, Strukov and his team are investigating whether there will be any drifts in the characteristics over time. They also are developing "strong" security paths that require larger memristive circuits and additional techniques (suitable for sensitive military equipment or highly classified information), and "weak" paths geared more toward consumer electronics and everyday gadgets—situations in which it would likely not be worth an attacker's time to spend hours or days hacking into a device.