A tiny wireless implant inserted under the retina can restore central vision to patients with sight loss due to age-related macular degeneration (AMD). In an international clinical trial, the PRIMA (photovoltaic retina implant microarray) system restored the ability to read in 27 of 32 participants followed up after a year.
AMD is the most common cause of incurable blindness in older adults. In its advanced stage, known as geographic atrophy, AMD can cause progressive, irreversible death of light-sensitive photoreceptors in the centre of the retina. This loss of photoreceptors means that light is not transduced into electrical signals, causing profound vision loss.
The PRIMA system works by replacing these lost photoreceptors. The two-part system includes the implant itself: a 2 x 2 mm array of 378 photovoltaic pixels, plus PRIMA glasses containing a video camera that captures images and, after processing, projects them onto the implant using near-infrared light. The pixels in the implant convert this light into electrical pulses, restoring the flow of visual information to the brain. Patients can use the glasses to focus and zoom the image that they see.
The clinical study, led by Frank Holz of the University of Bonn in Germany, enrolled 38 participants at 17 hospital sites in five European countries. All participants had geographic atrophy due to AMD in both eyes, as well as loss of central sight in the study eye over a region larger than the implant (more than 2.4 mm in diameter), leaving only limited peripheral vision.
Around one month after surgical insertion of the 30 μm-thick PRIMA array into one eye, the patients began using the glasses. All underwent training to learn to interpret the visual signals from the implant, with their vision improving over months of training.
After one year, 27 of the 32 patients who completed the trial could read letters and words (with some able to read pages in a book) and 26 demonstrated clinically meaningful improvement in visual acuity (the ability to read at least two extra lines on a standard eye chart). On average, participants could read an extra five lines, with one person able to read an additional 12 lines.
Nineteen of the participants experienced side-effects from the surgical procedure, with 95% of adverse events resolving within two months. Importantly, their peripheral vision was not impacted by PRIMA implantation. The researchers note that the infrared light used by the implant is not visible to remaining photoreceptors outside the affected region, allowing patients to combine their natural peripheral vision with the prosthetic central vision.
“Before receiving the implant, it was like having two black discs in my eyes, with the outside distorted,” Sheila Irvine, a trial patient treated at Moorfields Eye Hospital in the UK, says in a press statement. “I was an avid bookworm, and I wanted that back. There was no pain during the operation, but you’re still aware of what’s happening. It’s a new way of looking through your eyes, and it was dead exciting when I began seeing a letter. It’s not simple, learning to read again, but the more hours I put in, the more I pick up. It’s made a big difference.”
The PRIMA system – originally designed by Daniel Palanker at Stanford University – is being developed and manufactured by Science Corporation. Based on these latest results, reported in the New England Journal of Medicine, the company has applied for clinical use authorization in Europe and the United States.
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China is on track to land its first crew on the lunar surface by 2030 and establish a base at the resource-rich south pole — a site that offers continuous sunlight, access to water ice and control of the most valuable real estate beyond Earth. Beijing’s record of steady, disciplined progress in space suggests they […]
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Researchers in the Netherlands have demonstrated the first chip-based device capable of splitting phonons, which are quanta of mechanical vibrations. Known as a single-phonon directional coupler, or more simply as a phonon splitter, the new device could make it easier for different types of quantum technologies to “talk” to each other. For example, it could be used to transfer quantum information from spins, which offer advantages for data storage, to superconducting circuits, which may be better for data processing.
“One of the main advantages of phonons over photons is they interact with a lot of different things,” explains team leader Simon Gröblacher of the Kavli Institute of Nanoscience at Delft University of Technology. “So it’s very easy to make them interface with systems.”
There are, however, a few elements still missing from the phononic circuitry developer’s toolkit. One such element is a reversible beam splitter that can either combine two phonon channels (which might be carrying quantum information transferred from different media) or split one channel into two, depending on its orientation.
While several research groups have already investigated designs for such phonon splitters, these works largely focused on surface acoustic waves. This approach has some advantages, as waves of this type have already been widely explored and exploited commercially. Mobile phones, for example, use surface acoustic waves as filters for microwave signals. The problem is that these unconfined mechanical excitations are prone to substantial losses as phonons leak into the rest of the chip.
Gröblacher and his collaborators chose instead to mimic the design of beam splitters used in photonic chips. They used a strip of thin silicon to fashion a waveguide for phonons that confined them in all dimensions but one, giving additional control and reducing loss. They then brought two waveguides into contact with each other so that one waveguide could “feel” the mechanical excitations in the other. This allowed phonon modes to be coupled between the waveguides – something the team demonstrated down to the single-phonon level. The researchers also showed they could tune the coupling between the two waveguides by altering the contact length.
Although this is the first demonstration of single-mode phonon coupling in this kind of waveguide, the finite element method simulations Gröblacher and his colleagues ran beforehand made him pretty confident it would work from the outset. “I’m not surprised that it worked. I’m always surprised how hard it is to get it to work,” he tells Physics World. “Making it to look and do exactly what you design it to do – that’s the really hard part.”
According to A T Charlie Johnson, a physicist at the University of Pennsylvania, US whose research focuses on this area, that hard work paid off. “These very exciting new results further advance the prospects for phonon-based qubits in quantum technology,” says Johnson, who was not directly involved in the demonstration. “Integrated quantum phononics is one significant step closer.”
As well as switching between different quantum media, the new single-phonon coupler could also be useful for frequency shifting. For instance, microwave frequencies are close to the frequencies of ambient heat, which makes signals at these frequencies much more prone to thermal noise. Gröblacher already has a company working on transducers to transform quantum information from microwave to optical frequencies with this challenge in mind, and he says a single-phonon coupler could be handy.
One remaining challenge to overcome is dispersion, which occurs when phonon modes couple to other unwanted modes. This is usually due to imperfections in the nanofabricated device, which are hard to avoid. However, Gröblacher also has other aspirations. “I think the one component that’s missing for us to have the similar level of control over phonons as people have with photons is a phonon phase shifter,” he tells Physics World. This, he says, would allow on-chip interferometry to route phonons to different parts of a chip, and perform advanced quantum experiments with phonons.
The study is reported in Optica.
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South Korean launch startup Innospace says it has received government approval for its first orbital launch attempt, which could take place as soon as the end of the month.
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China conducted the first launch for the Thousand Sails constellation since March as the country continues its recent rapid rate of orbital launches.
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The award is part of NGA’s Luno program
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Krakow — The European Commission presented a working plan to track progress and deliver key defense capabilities by 2030 to European Union member states on October 16. The roadmap, titled Preserving Peace – Defence Readiness Roadmap 2030, follows March’s White Paper for European Defence – Readiness 2030 and the broader ReArm Europe/Readiness 2030 package, which […]
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German launch startup HyImpulse has raised 45 million euros ($53 million) as it works to avoid becoming an also-ran in the European space launch race.
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Researchers in the US have discovered that a tiny jumping worm uses static electricity to increase the chances of attaching to its unsuspecting prey.
The parasitic roundworm Steinernema carpocapsae, which live in soil, are already known to leap some 25 times their body length into the air. They do this by curling into a loop and springing in the air, rotating hundreds of times a second.
If the nematode lands successfully, it releases bacteria that kills the insect within a couple of days upon which the worm feasts and lays its eggs. At the same time, if it fails to attach to a host then it faces death itself.
While static electricity plays a role in how some non-parasitic nematodes detach from large insects, little is known whether static helps their parasitic counterparts to attach to an insect.
To investigate, researchers are Emory University and the University of California, Berkeley, conducted a series of experiments, in which they used highspeed microscopy techniques to film the worms as they leapt onto a fruit fly.
They did this by tethering a fly with a copper wire that was connected to a high-voltage power supply.
They found that a charge of a few hundred volts – similar to that generated in the wild by an insect’s wings rubbing against ions in the air – fosters a negative charge on the worm, creating an attractive force with the positively charged fly.
Carrying out simulations of the worm jumps, they found that without any electrostatics, only 1 in 19 worm trajectories successfully reached their target. The greater the voltage, however, the greater the chance of landing. For 880 V, for example, the probability was 80%.
The team also carried out experiments using a wind tunnel, finding that the presence of wind helped the nematodes drift and this also increased their chances of attaching to the insect.
“Using physics, we learned something new and interesting about an adaptive strategy in an organism,” notes Emory physicist Ranjiangshang Ran. “We’re helping to pioneer the emerging field of electrostatic ecology.”
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It isn’t surprising that more and more space companies are pivoting to defense. Defense budgets are rising across the board, and rising quickly. In fact, the sum of money set to be available is eye-watering. Now that NATO has pledged to spend 5% of GDP by 2035, McKinsey thinks that annual defense spending across the […]
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