Lawrence Livermore National Laboratory



Artificial Retina: Invention of the Year

A Department of Energy–funded project resulted in the first-ever retinal prosthesis—or bionic eye—approved in the U.S. by the Food and Drug Administration for blind individuals with end-stage retinitis pigmentosa, a group of degenerative diseases that affects two million people worldwide. The artificial retina has enough resolution for people to see the lines of a crosswalk, find objects, and read letters a couple of centimeters tall. The invention, in which Lawrence Livermore played a prominent role, earned a place in the top 25 best inventions of 2013 from Time Magazine. The artificial retina also garnered a 2013 best innovation designation from Popular Science.

The invention was commercialized by Second Sight Medical Products, Inc., and is now called the Argus II Retinal Prosthesis System, which gives sight to the blind. The device consists of a miniature video camera that is mounted on a pair of glasses and sends footage to a microprocessor worn on a person’s belt. The processor converts the visual data to electronic signals, which are transmitted wirelessly to a 60-pixel electrode array implanted in the back of the eye. The optic nerve picks up these signals and sends them to the brain, where they are interpreted as rudimentary gray-scale images. 

The Livermore team contributed three major components to the artificial retina project: the thin-film electrode array that contains the neural electrodes, the biocompatible electronics package that stimulates the retina and powers the wireless communication, and an ocular surgical tool that enables the replacement of the thin-film electrode array. In addition, Livermore was responsible for the system integration and assembly of the next-generation artificial retina system with 240 stimulating electrodes. Future trials are planned to test for the treatment of macular degeneration, the most common cause of blindness in Americans over the age of 60. 
Contact: Satinderpall Pannu (925) 422-5095 (pannu1@llnl.gov).

Examining the Origins of Life on Earth

Shock-compression experiments by a team of international scientists have provided the first confirmation that life on Earth may come from out of this world—a prediction made by Livermore physical chemist Nir Goldman. (See S&TR, June 2011, Life from Outer Space.) Supercomputing simulations that Goldman ran in 2010 and again in 2013 indicate that the impact of icy comets crashing into Earth billions of years ago could have produced a variety of prebiotic or life-building compounds, including amino acids. His work predicted that the simple molecules found in comets (such as water, ammonia, methanol, and carbon dioxide) could have supplied the raw materials for prebiotic chemistry, and the impact with early Earth would have yielded an abundant supply of energy to drive the reactions.

In an effort to examine Goldman’s predictions, collaborators from Imperial College in London and the University of Kent designed a series of experiments that mimicked the simulations. Using a light-gas gun, they fired a projectile into an icy mixture similar to the molecules found in comets. The shock compression of this mixture created several types of amino acids, confirming that the impact itself can yield life-building compounds. As a result, says Goldman, “This phenomena increases the probability of life originating and being widespread throughout our solar system.” The research was published in the September 2013 online edition of Nature Geoscience.
Contact: Nir Goldman (925) 422-3994 (goldman14@llnl.gov).

Human Activity Affects Atmospheric Vertical Temperature

Scientists from Lawrence Livermore and six other scientific institutions reported that human influences have directly affected the latitude and altitude pattern of atmospheric temperature. Their research compares multiple satellite records of atmospheric temperature change with results from a large, multimodel archive of simulations. “Human activity has very different effects on the temperature of the upper and lower atmosphere, and a very different fingerprint from purely natural influences,” says Benjamin Santer, the lead researcher in a paper appearing in the October 22, 2014, edition of the Proceedings of the U.S. National Academy of Sciences. Observational satellite data and the computer-model-predicted response to human influence have a common latitude–altitude pattern of atmospheric temperature change. The key features of this pattern are global-scale tropospheric warming and stratospheric cooling over the 34-year satellite temperature record.

Natural internal fluctuations in climate are generated by complex interactions of the coupled atmosphere–ocean system, such as the well-known El Niño Southern Oscillation. External influences include human-caused changes in well-mixed greenhouse gases, stratospheric ozone, and other radiative forcing agents, as well as purely natural fluctuations in solar irradiance and volcanic aerosols. Each of these external influences has a unique “fingerprint” in the detailed latitude–altitude pattern of atmospheric temperature change. Fingerprint information has proved particularly useful in separating human, solar, and volcanic influences on climate.

“The pattern of temperature change that has been observed vertically in the atmosphere, from ground level to the stratosphere, fits with what is expected from human-caused increases in greenhouse gases,” says Santer. “The observed pattern conflicts with what would be expected from an alternative explanation, such as fluctuations in the Sun’s output.” Coauthor Celine Bonfils adds, “In contrast to volcanic influences, human-caused atmospheric temperature changes affect all latitudes and last longer.”
Contact: Benjamin Santer (925) 423-3364 (santer1@llnl.gov).