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Implant could help people without a retina see.
March 24, 2017

Associate Professor Bradley Greger working with California company Second Sight on cortical device for people without a retina

An Arizona State University neuroscientist is helping a private company develop a brain implant that will help the blind to see.

Intended for use by people without a retina — the largest segment of the blind population — the device is expected to enable the blind to see light and shapes and, in a best-case scenario, allow them to read a large-print book.

Bradley Greger, an associate professor in the School of Biological and Health Systems Engineering, part of the Ira A. Fulton Schools of Engineering, is working with a California company on a cortical implant.

Second Sight Medical Products makes a retinal prosthesis that is on the market in 12 countries. It works by converting images captured on a miniature video camera mounted on glasses into a series of small electrical pulses. The pulses are transmitted wirelessly to an electrode array implanted on the retina.

The pulses stimulate the retina’s remaining cells, giving the perception of patterns of light. Patients learn to interpret the patterns, gaining some useful vision.

The implant Greger is working on is for people born without a retina, or whose retina was destroyed by cancer, trauma or glaucoma.

“What I’m doing is helping them do is take that technology to a cortical implant,” Greger said. “Some people just don’t have a retina. ... I’m taking their technology and expanding it so where we can go straight into the visual cortex of the brain and then get those people to see. It’s a much larger segment of the blind population.”

The cortex is much bigger than the retina, freeing up space to attach the implant. The retina is much smaller, and workspace, so to speak, is limited.

Animation of a bionic eye implant and the brain

Designed for people without a retina, the device would be implanted directly on the visual cortex. Because the cortex is much larger than a retina, the developers are hoping to achieve a better, more detailed result. Image courtesy of Second Sight Medical Products

 

“That’s one of the things we’re helping to sort out,” Greger said. “Can we really restore better vision by going into the cortex versus the retina? ... It’s a larger target, so we can get more electrodes per visual angle. We’re hoping to get a little bit better; maybe they could read a large-print book. That would be awesome if we could get that sort of thing.”

Ken Spector was born with cancer and blinded at a very early age. A program coordinator for Alternative Format Services with ASU’s Disability Resource Center — he specializes in Braille — Spector said, “It’s something I’d be interested in trying.”

Within a large portion of the deaf community, being deaf is considered part of their identity, and not something they would want to change through surgery or a device.

In the blind community, “I think it’s less pronounced,” Spector said.

“In the deaf community, there are those who feel that way, but it’s a very broad spectrum; there are hardliners and more moderates,” he said. “The same holds true in the blind community, but there’s a much smaller percentage of the blind community who would be of that mind-set. There would be some who would be against it based on being of the philosophy that they should be satisfied with what they are. But there are others who would want to try it because it’s a new technology. I’m sure there would be quite a few who would be interested.”

Greger’s role with Second Sight is as a research collaborator.

“They’ve put about 15 years of work into this and about $100 million,” he said. “I did not do this on my own. ... We’re helping them do some research and expand the applications for their product. ... It does have to be redesigned for the cortex, and we’re helping them work that out, how to do that optimally.”

Greger estimates Second Sight will push for a clinical trial in the next year or two. The company announced a successful trial implant in a 30-year-old patient in October, providing the first human proof of concept.

The patient was implanted with a wireless multichannel neurostimulation system called the Orion I on the visual cortex and was able to perceive and localize individual spots of light with no significant adverse side effects.

“It is rare that technological development offers such stirring possibilities,” Dr. Robert Greenberg, chairman of the board of Second Sight, said in a press release. “By bypassing the optic nerve and directly stimulating the visual cortex, the Orion I has the potential to restore useful vision to patients completely blinded due to virtually any reason, including glaucoma, cancer, diabetic retinopathy or trauma. Today these individuals have no available therapy, and the Orion I offers hope, increasing independence and improving their quality of life.”

 

Top image: A still from an animation showing the implant's placement. Image courtesy of Second Sight Medical Products

Scott Seckel

Reporter , ASU Now

480-727-4502

 
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March 27, 2017

Test outperforms all others on market and takes just hours to complete, key in fighting disease that remains major worldwide risk

Tuberculosis, once better known as consumption for the way its victims wasted away, has a long and deadly history, with estimates indicating it may have killed more people than any other bacterial pathogen.

Consumption played a role in many of our stories of the Old West, but even today — despite $6.6 billion spent for international TB care and prevention efforts — it remains a major risk to human health.

A group of maverick scientists from Arizona, Texas and Washington, D.C., has teamed up to develop the first rapid blood test to diagnose and quantitate the severity of active TB cases.

Led by Tony Hu, a researcher at Arizona State University’s Biodesign Institute, eight research groups, including the Houston Methodist Research Institute and scientists at the National Institutes of Health, are harnessing the new field of nanomedicine to improve worldwide TB control.

“In the current frontlines of TB testing, coughed-up sputum, blood culture tests, invasive lung and lymph biopsies, or spinal taps are the only way to diagnose TB,” said Hu, an associate professor at the ASU's School of Biological and Health Systems Engineering, part of the Ira A. Fulton Schools of Engineering. “The results can give false negatives, and these tests are further constrained because they can take days to weeks to get the results.”

The team’s newly developed blood-based TB test not only outperforms all others on the market but also takes just hours to complete. This is critical since effective TB control requires that patients start treatment as soon as possible to reduce the risk of spreading it.

This test also holds promise for rapid assessment of TB treatment, an important factor in reducing the development and spread of drug-resistant strains.

And in a fitting twist of fate, Hu’s laboratory in the Biodesign Institute's Virginia G. Piper Center for Personalized Diagnostics is only about a mile away from the original Arizona State Tuberculosis Sanatorium, a Moorish-influenced structure that opened in Tempe, Arizona, in 1934 and had 60 beds available to treat patients.

A history of affliction

Estimates suggest that TB has killed a billion people over the past two centuries.

Locally, TB deeply influenced the early history of Arizona, since the warm, dry climate spurred the growth of sanatoriums and a medical tourism industry that helped give rise to Phoenix’s original population boom in the late 1800s.

Perhaps the most notorious TB victim in Arizona’s rich history was the Old West's John Henry “Doc” Holliday, a dentist, gambler and gunfighter, whose role at the OK Corral shootout is still re-enacted daily in Tombstone. After the gun smoke cleared, Holliday survived but died just a few years later, finally succumbing to the disease he seems to have contracted a decade earlier.

TB appears to have played a major role in his life, first influencing his migration west for a healthier climate, but also branding him with a prevailing social stigma. In the hit movie “Tombstone,” Doc Holliday’s enemies taunted him by calling him “lunger,” a derogatory term for those afflicted with consumption, who were stigmatized and often removed from society and placed in sanatoriums, such as the one near Hu’s modern-day lab. 

Worldwide scourge

Thankfully, TB now has a greatly reduced impact on Arizona, but it remains a major risk, particularly for the developing world and people with HIV infections.

Making matters worse, TB bacteria, such as in Holliday's case, can lurk dormant in a person’s lung tissue, often for decades, before spontaneously producing full-blown TB disease that can then spread to others. Currently, the World Health Organization (WHO) estimates that up to one-third of the world’s population may have such dormant TB infections.

In 2016, an estimated 10 million people worldwide still develop TB each year, according to the WHO’s most recent report, resulting in almost 2 million deaths. TB treatment has prevented almost 50 million deaths between 2000 and 2015, but TB remains a worldwide epidemic due to the lack of an effective vaccine, the rise in drug-resistant strains and the relatively poor performance of available diagnostics.

A new and easy way to rapidly screen those susceptible to TB infections was recognized by WHO and other public health officials as the major technological hurdle needed to overcome the disease.

Enter Hu and the research team.

Nanomedicine to the rescue

The research team’s newly developed NanoDisk-MS assay (see image below), could significantly improve TB diagnosis and management because it is the first test that can measure the severity of active TB infections. It does so by accurately detecting minute blood levels of two proteins (CFP-10 and ESAT-6) that TB bacteria release only during active infections.

The research team’s newly developed NanoDisk-MS assay could significantly improve TB diagnosis and management because it is the first test that can measure the severity of active TB infections. It does so by accurately detecting minute blood levels of two proteins (CFP-10 and ESAT-6) that TB bacteria release only during active infections.

 

“We are particularly excited about the ability of our high-throughput assay to provide rapid quantitative results that can be used to monitor treatment effects, which will give physicians the ability to better treat worldwide TB infections,” said Hu. “Furthermore, our technology can be used with standard clinical instruments found in hospitals worldwide.”

Current TB assays often demonstrate reduced performance with HIV-positive TB patients or those with TB infections in non-lung tissues, and these patients can require tissue biopsies for diagnosis. The NanoDisk-MS assay, however, detected lung- and non-lung-resident TB cases with similar sensitivity (about 92 percent) regardless of patient HIV status, and revealed good specificity to distinguish patients with related disease cases (latent TB and nontuberculous mycobacterial infections; 87 and 91 percent, respectively) and healthy subjects (100 percent).

The strategy used to generate this assay may also be adaptable to other infectious diseases. Hu is now developing the current TB assay for clinical approval and hopes to make it available for clinical use as soon as possible to re-establish the role of Arizona and ASU as central players in the fight against TB.  

The study, “Quantification of circulating M. tuberculosis antigen peptides allows rapid diagnosis of active disease and treatment monitoring,” was published in the Early Edition of the journal Proceedings of the National Academy of Sciences.

 

Top image: An illustration depicting an active TB infection targeting the lungs. Courtesy of the ASU Biodesign Institute

Joe Caspermeyer

Managing editor , Biodesign Institute

480-258-8972