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<![CDATA[ Latest from Live Science ]]>
https://www.livescience.com
- Fri, 02 Jan 2026 16:15:00 +0000
+ Fri, 02 Jan 2026 19:00:00 +0000en
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+ <![CDATA[ An experimental mRNA treatment counters immune cell aging in mice ]]>
+ A new mRNA treatment rejuvenates key immune cells in the body, which could help them fight off infections and cancer, a mouse study suggests.
T cells help train other immune cells to fight off disease. But as the body ages, the activity of these T cells declines, and they become less responsive to threats. Additionally, the thymus gland — where T cells mature — begins to shrink with age. These impacts of aging may explain why vaccines and immune-boosting cancer therapies don't work as well in older adults as they do in younger adults, Nature News reported.
In the new study, published Dec. 17 in the journal Nature, scientists tried to counteract these age-driven changes using messenger RNA (mRNA).
Among other roles, mRNA relays instructions from DNA to cells' protein-building organelles, serving as a template from which new proteins are made. The team behind the new study studied T cells in aging mice, pinpointing three proteins that seemed to decline with age, contributing to the aging process. They then generated mRNA for those three proteins, encased them in tiny bubbles of fat, and injected them into middle-aged mice, which were around 16 months old.
These mRNA-filled bubbles traveled through the bloodstream to the liver, where they accumulated. Most T cells are in the bloodstream, and because the liver filters blood, T cells were likely cycled through the liver, where they were exposed to this waiting supply of mRNA.
Mice treated with the mRNA made more T cells than mice that were left untreated. The treated mice's T cells also responded better to vaccination and to cancer immunotherapy, the experiments suggested.
The benefits of the treatment, which was given to the mice twice a week, disappeared quickly when the scientists paused the injections. That's not necessarily surprising, given that mRNA molecules degrade very quickly in the body, whether they were originally made by cells or produced in a lab.
"The transient nature of mRNA delivery necessitates repeated administrations to sustain therapeutic effects," the study authors wrote in the paper. That said, "the long-term consequences of continuous exposure to these factors, especially in aged individuals should be analysed through extensive long-term safety studies."
In short, more research is needed to see if the same approach could work in humans. You can read more about the study in Nature News.
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+ https://www.livescience.com/health/immune-system/an-experimental-mrna-treatment-counters-immune-cell-aging-in-mice
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+ ufTyjNTBCNeCGezQ4coLRn
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+ Fri, 02 Jan 2026 19:00:00 +0000Tue, 23 Dec 2025 22:01:14 +0000
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+ <![CDATA[ Yellowstone quiz: How much do you know about the first national park? ]]>Spanning over 2.2 million acres (890,000 hectares), Yellowstone National Park is stuffed full of stupendous scenery created by volcanoes and earthquakes or carved out by ice and water.This rich environment also creates a home for a multitude of wildlife, but how much do you really know about it? Start the quiz below to find out if your knowledge is steaming hot like a geyser or stuck back in the ice age.
Remember to log in to put your name on the leaderboard; hints are available if you click the yellow button!
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- <![CDATA[ Canon RF 200-800mm f/6.3-9 IS USM lens review: Enormous reach for wildlife photography ]]>
- It’s no secret that the best lenses for wildlife photography are among the most expensive lenses you can buy. Finding a versatile, good-quality lens with the reach and prowess needed for photographing distant animals is a tough feat if you don’t have a huge budget, but the Canon RF 200-800mm f/6.3-9 IS USM lens could be just what you’re looking for. With one of the widest focal ranges out there, it’s a wildlife photographer's dream — and, provided you’re shooting in favorable conditions, no animal will be out of reach.
We’ve taken it to a nature reserve, photographed birds from our window and zoomed in on the moon to assess its performance in all-light conditions for static and moving subjects, emulating real-world shooting conditions to test its mettle.
Canon RF 200-800mm f/6.3-9 IS USM review
Canon RF 200-800mm f/6.3-9 IS USM: Design
It's a beast of a lens, even without the lens hood. (Image credit: Kimberley Lane)
Big and heavy
Annoying amount of lens creep
Solid and well-built
Custom buttons difficult to access
There’s no beating around the bush here — this lens is big, and it’s heavy. Weighing about 4.5 lbs (just over 2 kilograms), this thing makes itself known both in your camera bag and out in the field. Needless to say, it got quite heavy after a while, even when resting in a hide, but it feels solid and well-built and is dust- and weather-resistant, although we never got caught out in the rain to fully test this.
We found it frustrating that it didn’t have a zoom lock, as it had an annoying amount of lens creep when we held the lens vertically, which meant we couldn’t carry the camera around our neck (as if its weight didn’t already see to that). We found the zoom ring a little on the stiff side, and, to be picky, the lens actually looked quite ugly when it was zoomed all the way in on a subject.
Image 1 of 2
We thought it looked somewhat unsightly when zoomed in (no offense intended!) (Image credit: Kimberley Lane)
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It has a number of buttons and dials on the lens barrel. (Image credit: Kimberley Lane)
Specifications
Focal length: 200-800 mm Maximum aperture: f/6.3-9 Weight: 4.5 pounds (2.05 kg) Image stabilization: 5.5 stops Filter thread: 95 mm Dimensions (in): ⌀4.03 x 12.37 Dimensions (mm): ⌀102.3 x 314.1
In addition, it has a control ring, AF/MF switch, image stabilizer switch and two custom buttons, although we found these buttons hard to press as they aren’t within easy reach when holding the camera’s hefty weight. When we took our hand away to try to press either of the buttons, it threw the entire weight distribution off.
It has a nice big lens hood, although we’d have liked this to have a door in order to utilize a polarizer, particularly when we were photographing waterfowl.
Canon RF 200-800mm f/6.3-9 IS USM: Performance
Image 1 of 5
We could easily focus on a robin among the trees, provided there was a clear view. (Image credit: Kimberley Lane)
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(Image credit: Kimberley Lane)
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(Image credit: Kimberley Lane)
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(Image credit: Kimberley Lane)
Image 5 of 5
(Image credit: Kimberley Lane)
Struggles in the dark with f/6.3 aperture
Good autofocus performance
Excellent image quality
For wildlife photography in generally favorable conditions, this lens performed very well overall. Its obvious downfall is the limited maximum aperture — f/6.3 performs just fine during the daytime, but as the light levels fell at dusk, or even when we went into a heavily wooded area, we had to push the ISO up higher than we’d have wanted.
Luckily, we were shooting with the Canon EOS R6 II, which has excellent noise handling, so we were able to save a lot of our images. But if you often shoot at dawn or dusk, we’d recommend investing in a wider telephoto lens so you won’t need to rely on denoise software.
The autofocus was also good, but at higher focal lengths, it’s at the mercy of how steady your hand is. It generally performed very well, but it suffered when we were shooting in harsh conditions, or if there were distractions or foliage in front of our subject.
Overall, though, its performance is very good for the price. Images are sharp and it captures color very nicely — certainly more than well enough for wildlife or moon photography.
Canon RF 200-800mm f/6.3-9 IS USM: Functionality
Image 1 of 5
At 200mm, the close focus is great for photographing bees and butterflies. (Image credit: Kimberley Lane)
Image 2 of 5
(Image credit: Kimberley Lane)
Image 3 of 5
(Image credit: Kimberley Lane)
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(Image credit: Kimberley Lane)
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The moon at 800mm. (Image credit: Kimberley Lane)
5.5 stops of image stabilization is crucial
Versatile focal length
2.6 ft (0.8 meter) close focusing distance at 200mm is great for insects
As much as it suffers from a fairly wide maximum aperture, the 200-800mm focal length offers versatility that many other lenses don’t. There’s a Sony super-telephoto with a 400-800mm range, but you’d be stuck if a subject came too close to you — with the Canon, you’d be able to zoom out easily. We never found ourselves wishing we had multiple lenses, as the 200-800mm can cover a lot of subjects, near or far.
Plus, although it doesn’t have the close focusing capabilities of a true macro lens, it can focus as close as 2.6 feet (0.8 meters) at 200mm, which is great for photographing butterflies and insects at a fairly close range.
The 5.5 stops of image stabilization were a lifesaver, and pretty crucial for such a long focal length. Even just for compositional purposes, we still struggled to follow subjects on occasion at the full 800mm, and if there had been no image stabilization, we’d have had no chance.
Should you buy the Canon RF 200-800mm f/6.3-9 IS USM?
Overall, this lens provides excellent value for money. You get a lot of lens for the price, and although it’s not a low-light champion, it still produces beautifully sharp, contrast-y images, while the versatility of the focal length is hard to beat.
Considering the very best wildlife lenses are telephoto primes costing upwards of $10,000, it’s one of the best you can buy for most wildlife photographers — that is, for anyone who’s not a serious pro.
If the Canon RF 200-800mm f/6.3-9 IS USM isn't for you
If you don't need 800mm
Canon RF 100-500mm F4.5-7.1L IS USM
Another great wildlife lens with a little less reach, but a little more aperture. This lens would be better in low light if you don't need a huge zoom.
If you'd prefer a prime lens
Canon RF 800mm F11 IS STM
This 800mm prime lens is perfect for bird photography or capturing distant animals on a budget — but the f/11 aperture means good lighting is essential.
If you're a professional
Canon RF 400mm F2.8L IS USM
If you're a pro photographer and have serious cash to spend, this 400mm prime lens with an f/2.8 aperture will see you through any light conditions.
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- https://www.livescience.com/technology/canon-rf-200-800mm-f-6-3-9-is-usm-lens-review-enormous-reach-for-wildlife-photography
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- Tue, 30 Dec 2025 14:00:00 +0000Wed, 17 Dec 2025 16:21:19 +0000
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- <![CDATA[ Tractor beams inspired by sci-fi are real, and could solve the looming space junk problem ]]>In science fiction films, nothing raises tension quite like the good guys' spaceship getting caught in an invisible tractor beam that allows the baddies to slowly reel them in. But what was once only a sci-fi staple could soon become a reality.
Scientists are developing a real-life tractor beam, dubbed an electrostatic tractor. This tractor beam wouldn't suck in helpless starship pilots, however. Instead, it would use electrostatic attraction to nudge hazardous space junk safely out of Earth orbit.
The science is pretty much there, but the funding is not.
The electrostatic tractor beam could potentially alleviate that problem by safely moving dead satellites far out of Earth orbit, where they would drift harmlessly for eternity.
While the tractor beam wouldn't completely solve the space junk problem, the concept has several advantages over other proposed space debris removal methods, which could make it a valuable tool for tackling the issue, experts told Live Science.
A prototype could cost millions, and an operational, full-scale version even more. But if the financial hurdles can be overcome, the tractor beam could be operational within a decade, its builders say.
"The science is pretty much there, but the funding is not," project researcher Kaylee Champion, a doctoral student in the Department of Aerospace Engineering Sciences at the University of Colorado Boulder (CU Boulder), told Live Science.
Avoiding Disaster
Tractor beams are a staple of sci-fi films and TV shows, such as Star Trek. (Image credit: Star Trek)
The tractor beams depicted in "Star Wars" and "Star Trek" suck up spacecraft via artificial gravity or an ambiguous "energy field." Such technology is likely beyond anything humans will ever achieve. But the concept inspired Hanspeter Schaub, an aerospace engineering professor at CU Boulder, to conceptualize a more realistic version.
In the wake of this disaster, Schaub wanted to be able to prevent this from happening again. To do this, he realized you could pull spacecraft out of harm's way by using the attraction between positively and negatively charged objects to make them "stick" together.
Over the next decade, Schaub and colleagues refined the concept. Now, they hope it can someday be used to move dead satellites out of geostationary orbit (GEO) — an orbit around Earth's equator where an object's speed matches the planet's rotation, making it seem like the object is fixed in place above a certain point on Earth. This would then free up space for other objects in GEO, which is considered "prime real estate" for satellites, Schaub said.
How does it work?
The researchers have been testing the electron gun on pieces of metal in the lab. (Image credit: Nico Goda/CU Boulder)
The electrostatic tractor would use a servicer spacecraft equipped with an electron gun that would fire negatively charged electrons at a dead target satellite, Champion told Live Science. The electrons would give the target a negative charge while leaving the servicer with a positive charge. The electrostatic attraction between the two would keep them locked together despite being separated by 65 to 100 feet (20 to 30 meters) of empty space, she said.
Once the servicer and target are "stuck together," the servicer would be able to pull the target out of orbit without touching it. Ideally, the defunct satellite would be pulled into a "graveyard orbit" more distant from Earth, where it could safely drift forever, Champion said.
The electrostatic attraction between the two spacecraft would be extremely weak, due to limitations in electron gun technology and the distance by which the two would need to be separated to prevent collisions, project researcher Julian Hammerl, a doctoral student at CU Boulder, told Live Science. So the servicer would have to move very slowly, and it could take more than a month to fully move a single satellite out of GEO, he added.
That's a far cry from movie tractor beams, which are inescapable and rapidly reel in their prey. This is the "main difference between sci-fi and reality," Hammerl said.
Advantages and limitations
The amount of space junk surrounding Earth has greatly increased in recent years. Here is a comparison of space junk in 1965 (left) and 2010 (right). (Image credit: NASA)
The electrostatic tractor would have one big advantage over other proposed space junk removal methods, such as harpoons, giant nets and physical docking systems: It would be completely touchless.
"You have these large, dead spacecraft about the size of a school bus rotating really fast," Hammerl said. "If you shoot a harpoon, use a big net or try to dock with them, then the physical contact can damage the spacecraft and then you are only making the [space junk] problem worse."
Scientists have proposed other touchless methods, such as using powerful magnets, but enormous magnets are both expensive to produce and would likely interfere with a servicer's controls, Champion said.
The main limitation of the electrostatic tractor is how slowly it would work. More than 550 satellites currently orbit Earth in GEO, but that number is expected to rise sharply in the coming decades.
If satellites were moved one at a time, then a single electrostatic tractor wouldn't keep pace with the number of satellites winking out of operation. Another limitation of the electrostatic tractor is that it would work too slowly to be practical for clearing smaller pieces of space junk, so it wouldn't be able to keep GEO completely free of debris.
Cost is the other big obstacle. The team has not yet done a full cost analysis for the electrostatic tractor, Schaub said, but it would likely cost tens of millions of dollars. However, once the servicer were in space, it would be relatively cost-effective to operate it, he added.
Next steps
Researcher Julian Hammerl photographed next to the ECLIPS machine at CU Boulder. (Image credit: Nico Goda/CU Boulder)
The researchers are currently working on a series of experiments in their Electrostatic Charging Laboratory for Interactions between Plasma and Spacecraft (ECLIPS) machine at CU Boulder. The bathtub-sized, metallic vacuum chamber, which is equipped with an electron gun, allows the team to "do unique experiments that almost no one else can currently do" in order to simulate the effects of an electrostatic tractor on a smaller scale, Hammerl said.
Once the team is ready, the final and most challenging hurdle will be to secure funding for the first mission, which is a process they have not yet started.
Most of the mission cost would come from building and launching the servicer. However, the researchers would ideally like to launch two satellites for the first tests, a servicer and a target that they can maneuver, which would give them more control over their experiments but also double the cost.
If they can somehow wrangle that funding, a prototype tractor beam could be operational in around 10 years, the team previously estimated.
Is it viable?
Space junk is becoming a major problem for the space exploration industry. (Image credit: CU Boulder)
While tractor beams may sound like a pipe dream, experts are optimistic about the technology.
"Their technology is still in the infancy stage," John Crassidis, an aerospace scientist at the University at Buffalo in New York, who is not involved in the research, told Live Science in an email. "But I am fairly confident it will work."
If you shoot a harpoon, use a big net or try to dock with them, then the physical contact can damage the spacecraft and then you are only making the [space junk] problem worse.
Removing space junk without touching it would also be much safer than any current alternative method, Crassidis added.
The electrostatic tractor "should be able to produce the forces necessary to move a defunct satellite" and "certainly has a high potential to work in practice," Carolin Frueh, an associate professor of aeronautics and astronautics at Purdue University in Indiana, told Live Science in an email. "But there are still several engineering challenges to be solved along the way to make it real-world-ready."
Scientists should continue to research other possible solutions, Crassidis said. Even if the CU Boulder team doesn't create a "final product" to remove nonfunctional satellites, their research will provide a stepping stone for other scientists, he added.
"What is today's science fiction could be tomorrow's reality," Crassidis said.
]]>
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+ <![CDATA[ Canon RF 200-800mm f/6.3-9 IS USM lens review: Enormous reach for wildlife photography ]]>
+ It’s no secret that the best lenses for wildlife photography are among the most expensive lenses you can buy. Finding a versatile, good-quality lens with the reach and prowess needed for photographing distant animals is a tough feat if you don’t have a huge budget, but the Canon RF 200-800mm f/6.3-9 IS USM lens could be just what you’re looking for. With one of the widest focal ranges out there, it’s a wildlife photographer's dream — and, provided you’re shooting in favorable conditions, no animal will be out of reach.
We’ve taken it to a nature reserve, photographed birds from our window and zoomed in on the moon to assess its performance in all-light conditions for static and moving subjects, emulating real-world shooting conditions to test its mettle.
Canon RF 200-800mm f/6.3-9 IS USM review
Canon RF 200-800mm f/6.3-9 IS USM: Design
It's a beast of a lens, even without the lens hood. (Image credit: Kimberley Lane)
Big and heavy
Annoying amount of lens creep
Solid and well-built
Custom buttons difficult to access
There’s no beating around the bush here — this lens is big, and it’s heavy. Weighing about 4.5 lbs (just over 2 kilograms), this thing makes itself known both in your camera bag and out in the field. Needless to say, it got quite heavy after a while, even when resting in a hide, but it feels solid and well-built and is dust- and weather-resistant, although we never got caught out in the rain to fully test this.
We found it frustrating that it didn’t have a zoom lock, as it had an annoying amount of lens creep when we held the lens vertically, which meant we couldn’t carry the camera around our neck (as if its weight didn’t already see to that). We found the zoom ring a little on the stiff side, and, to be picky, the lens actually looked quite ugly when it was zoomed all the way in on a subject.
Image 1 of 2
We thought it looked somewhat unsightly when zoomed in (no offense intended!) (Image credit: Kimberley Lane)
Image 2 of 2
It has a number of buttons and dials on the lens barrel. (Image credit: Kimberley Lane)
Specifications
Focal length: 200-800 mm Maximum aperture: f/6.3-9 Weight: 4.5 pounds (2.05 kg) Image stabilization: 5.5 stops Filter thread: 95 mm Dimensions (in): ⌀4.03 x 12.37 Dimensions (mm): ⌀102.3 x 314.1
In addition, it has a control ring, AF/MF switch, image stabilizer switch and two custom buttons, although we found these buttons hard to press as they aren’t within easy reach when holding the camera’s hefty weight. When we took our hand away to try to press either of the buttons, it threw the entire weight distribution off.
It has a nice big lens hood, although we’d have liked this to have a door in order to utilize a polarizer, particularly when we were photographing waterfowl.
Canon RF 200-800mm f/6.3-9 IS USM: Performance
Image 1 of 5
We could easily focus on a robin among the trees, provided there was a clear view. (Image credit: Kimberley Lane)
Image 2 of 5
(Image credit: Kimberley Lane)
Image 3 of 5
(Image credit: Kimberley Lane)
Image 4 of 5
(Image credit: Kimberley Lane)
Image 5 of 5
(Image credit: Kimberley Lane)
Struggles in the dark with f/6.3 aperture
Good autofocus performance
Excellent image quality
For wildlife photography in generally favorable conditions, this lens performed very well overall. Its obvious downfall is the limited maximum aperture — f/6.3 performs just fine during the daytime, but as the light levels fell at dusk, or even when we went into a heavily wooded area, we had to push the ISO up higher than we’d have wanted.
Luckily, we were shooting with the Canon EOS R6 II, which has excellent noise handling, so we were able to save a lot of our images. But if you often shoot at dawn or dusk, we’d recommend investing in a wider telephoto lens so you won’t need to rely on denoise software.
The autofocus was also good, but at higher focal lengths, it’s at the mercy of how steady your hand is. It generally performed very well, but it suffered when we were shooting in harsh conditions, or if there were distractions or foliage in front of our subject.
Overall, though, its performance is very good for the price. Images are sharp and it captures color very nicely — certainly more than well enough for wildlife or moon photography.
Canon RF 200-800mm f/6.3-9 IS USM: Functionality
Image 1 of 5
At 200mm, the close focus is great for photographing bees and butterflies. (Image credit: Kimberley Lane)
Image 2 of 5
(Image credit: Kimberley Lane)
Image 3 of 5
(Image credit: Kimberley Lane)
Image 4 of 5
(Image credit: Kimberley Lane)
Image 5 of 5
The moon at 800mm. (Image credit: Kimberley Lane)
5.5 stops of image stabilization is crucial
Versatile focal length
2.6 ft (0.8 meter) close focusing distance at 200mm is great for insects
As much as it suffers from a fairly wide maximum aperture, the 200-800mm focal length offers versatility that many other lenses don’t. There’s a Sony super-telephoto with a 400-800mm range, but you’d be stuck if a subject came too close to you — with the Canon, you’d be able to zoom out easily. We never found ourselves wishing we had multiple lenses, as the 200-800mm can cover a lot of subjects, near or far.
Plus, although it doesn’t have the close focusing capabilities of a true macro lens, it can focus as close as 2.6 feet (0.8 meters) at 200mm, which is great for photographing butterflies and insects at a fairly close range.
The 5.5 stops of image stabilization were a lifesaver, and pretty crucial for such a long focal length. Even just for compositional purposes, we still struggled to follow subjects on occasion at the full 800mm, and if there had been no image stabilization, we’d have had no chance.
Should you buy the Canon RF 200-800mm f/6.3-9 IS USM?
Overall, this lens provides excellent value for money. You get a lot of lens for the price, and although it’s not a low-light champion, it still produces beautifully sharp, contrast-y images, while the versatility of the focal length is hard to beat.
Considering the very best wildlife lenses are telephoto primes costing upwards of $10,000, it’s one of the best you can buy for most wildlife photographers — that is, for anyone who’s not a serious pro.
If the Canon RF 200-800mm f/6.3-9 IS USM isn't for you
If you don't need 800mm
Canon RF 100-500mm F4.5-7.1L IS USM
Another great wildlife lens with a little less reach, but a little more aperture. This lens would be better in low light if you don't need a huge zoom.
If you'd prefer a prime lens
Canon RF 800mm F11 IS STM
This 800mm prime lens is perfect for bird photography or capturing distant animals on a budget — but the f/11 aperture means good lighting is essential.
If you're a professional
Canon RF 400mm F2.8L IS USM
If you're a pro photographer and have serious cash to spend, this 400mm prime lens with an f/2.8 aperture will see you through any light conditions.
]]>
+ https://www.livescience.com/technology/canon-rf-200-800mm-f-6-3-9-is-usm-lens-review-enormous-reach-for-wildlife-photography
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+ bWEx9cJk3qQjHx6jandWhA
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+ Tue, 30 Dec 2025 14:00:00 +0000Wed, 17 Dec 2025 16:21:19 +0000
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+ <![CDATA[ Scientists are developing a 'self-driving' device that helps patients recover from heart attacks ]]>Hospitals may soon be able to rely on a "self-driving" machine to help patients recover from heart attacks. This machine would deliver treatments to the patient, collect data on how their body responds, and then adjust their medications to stabilize the patient within parameters preset by their doctor.
This is the vision for the Autonomous Closed-Loop Intervention System (ACIS), a device being developed by scientists at NTT Research, an arm of global technology company NTT. The device has been tested in animal experiments but not in human patients yet.
The researchers' eventual goal is to allow the heart to rest and minimize its oxygen use in that critical recovery window after a patient experiences a cardiac emergency. The jobs that would be handled by ACIS are usually done by medical providers — but the idea is that the device could standardize and optimize the process to deliver better outcomes while relieving strain on doctors' already-limited resources.
"We think that this system will outperform the standard of care," said Dr. Joe Alexander, director of NTT Research's Medical and Health Informatics (MEI) lab.
ACIS stemmed from a larger effort spearheaded by the MEI Lab known as the Bio Digital Twin program. Its aim is to construct advanced virtual models of organ systems that can be personalized with an individual patient's data, providing a detailed and dynamic representation of their medical status and a testable model for developing treatment plans.
Live Science spoke with Alexander about Digital Twins, ACIS and his vision for how they might transform health care.
Nicoletta Lanese: When we're talking about a Bio Digital Twin, is it fair to say it's a virtual copy of the patient?
Dr. Joe Alexander: Probably the layperson would think of a Bio Digital Twin as a copy of the person. But actually, it's just a system of equations, modeling and simulation to represent a person to the extent that is relevant for the disease. It's a very specific application, so there's no single Bio Digital Twin representing the [whole] person.
In our case, although we set out to build a family of Bio Digital Twins to represent different organ systems for different types of important diseases, we're starting with the cardiovascular system. So when I talk about a Cardiovascular Bio Digital Twin, I'm not talking about even a copy of the heart; I'm talking about a mathematical representation of all of the systems necessary for looking at the cardiovascular system in a particular patient.
Dr. Joe Alexander predicts ACIS could someday "outperform the standard of care." (Image credit: Courtesy of NTT Research, Inc.)
NL: Could you talk about what kind of data goes into the model?
JA: This Cardiovascular Bio Digital Twin is representing pressures and flows throughout the cardiovascular system, including pressures and flows generated by all four chambers of the heart. … We are able to represent the cardiovascular system dynamics in pressures, flows and volumes.
NL: And how do you make that actionable for an individual patient?
JA: We're in the early stages of it, but we have a road map for how to do it. Basically, we first go after representing the "normal" cardiovascular system for patients. So, if we can get data around "normal," then that's very good. [Editor's note: The MEI Lab is working with partners such as the National Cerebral and Cardiovascular Center in Japan to get access to this kind of data.]
But probably what's most important is finding populations that are relevant to the particular patient — so, in this case, patients with cardiovascular disease or patients with heart failure. So we go after that population-level data; let's say for heart failure. Then, from that data, we can estimate parameters for our cardiovascular model that represent the general population of patients with heart failure.
Within that population, as you know, there's a lot of variability. So are there other characteristics specific to our patient that we can use? Maybe results from echocardiogram [EKG]; maybe age; maybe comorbidities [other medical conditions]; sex, male or female; or environment. And if there is genetic information available, then we can find a subpopulation that's even more relevant to the patient.
Now, with ACIS, we [would] actually hook up a patient to the "first guess" of our Cardiovascular Bio Digital Twin for what would match that patient based on population-level data. Since it's a feedback control system, the feedback will automatically adjust the parameter values to deliver the necessary drugs or device therapies that that particular patient needs for some prespecified cardiac output. In that way, we can further fine-tune the Digital Twin for that patient.
NL: Can you describe how ACIS and its feedback loop work?
JA: The idea is that it's a "self-driving" therapeutic, just like a self-driving car. But in this case, "self-driving" is delivering the appropriate drugs or, in severe cases, medical-device therapies that a patient may need.
We have a system where we specify — just type in the keyboard — the desired cardiac output, heart rate, left atrial pressure, arterial pressure that we want the patient to achieve. Then, syringes that are filled with the appropriate drugs to create those changes are driven by our model, or "best guess" for that particular patient. This is all after a patient has had the primary lesion [like a blood vessel blockage] treated in the cath lab.
Let's say they had a vessel that was occluded; it's already been opened up or a stent has been placed, and they go to the ICU [intensive care unit] or CCU [coronary care unit] in order to recover. Recovery means that the heart needs an opportunity to rest. That means letting the heart work as little as possible to maintain the desired cardiac output.
We have a certain regimen of drugs that are given. Catecholamines improve the ability of the heart to contract. Nitrates reduce afterload of the heart so it doesn't have to work against such a high load when it tries to inject into the arterial system. Diuretics decrease the circulating blood volume and remove blood from the lungs, which has built up due to the acute failure.
These drugs are typically given by a physician; they'll give one drug and look at the response, give another drug, the response, and manage that patient over several days. When our system achieves proper function — and we're almost there, I think — all those drugs can be given at once if we know how the system will respond. That saves us a lot of time in treating the patient.
The drugs are delivered by these autonomously controlled syringes; then the patient responds to them, and that response is fed back in this system. Those values are compared to the ones that we typed in the keyboard, and if there's a difference, then feedback systems work to reduce that difference. It also gives information to our Digital Twin for that patient, so that in the future, we have better representations of those resistors and capacitors in the model.
The Cardiovascular Digital Twin represents the dynamics of the cardiovascular system through mathematical equations and simulations. (Image credit: Getty Images)
NL: What stage of development has ACIS reached at this point?
JA: So, in animal experiments in dogs, last year for the first time, we experimentally induced acute heart failure and we were able to let this autonomous system correct the cardiac output, arterial pressure autonomously, while minimizing myocardial [heart muscle] oxygen consumption.
Since that first successful experiment about a year ago, we've had several other successful [animal] experiments, all the while improving our feedback system to be more complex, making it so that it can operate based on intermittent data, so you don't have to be continuously sampling. You can do it episodically.
We have several more years of work in optimizing this system, we think, in animal experimentation — probably about three years more. And then we'll be ready for first-in-human studies where ACIS will be used but with a clinician in the loop [for the initial human tests]. What ACIS would do is tell the physician what doses of these various drugs to deliver, and the physician would then make a decision whether to do it or not, as a safety measure.
Now, what I've been describing so far has mostly been about drugs, but the same algorithms work for medical devices, such as left ventricular assist devices [LVAD, a type of mechanical pump] or extracorporeal membrane oxygenation devices [ECMO, which circulates the blood to let the heart and lungs rest]. This is all within the scope of what we expect to achieve in experimental animals within the next three years before going to first-in-human studies.
NL: What are the next steps toward getting ACIS approved? What might the trials look like?
JA: It would be kind of like [testing] an autonomous or self-driving vehicle — level 1 through 4 degrees, or stages, of autonomy.
In other words, allowing the system to have increasing responsibility and watching the performance until settling into acceptance of an autonomous system where then, still, probably a specialist would monitor it — like someone sitting in the seat of a self-driving car, ready to take over if things go wrong. I see that kind of progression, similar to the self-driving vehicle.
NL: And in the long run, would ACIS always have some kind of clinician supervision?
JA: I still hold to the concept of "autonomous," but I suspect that there will be a cardiologist somewhere roaming around, monitoring, perhaps, a number of patients at once.
I'm very committed to the idea that the device that we conceive of can actually outperform the cardiologist. And I know that we'll rub some cardiologists the wrong way. But we expect to demonstrate that point, or strongly suggest that that's true, by doing experiments in animals where we compare the ACIS system to clinically trained cardiologists. We expect reduced infarct size [degree of heart tissue death] from ACIS compared to the standard of care from cardiologists.
NL: Assuming this device gets approved in the future, where do you see it having the most benefit?
JA: There's the so-called Quintuple Aim of Health Care, which says to improve the patient experience, improve the physician experience, improve population health, reduce the cost of care, and improve health equity. These aims, I think, are all addressed by ACIS.
The patient would have more attention and minute-to-minute care — you wouldn't have a resident trying to juggle many patients at once. You could have a less-specialized clinical caretaker who is watching the behavior of the device, and so that would improve not only the patient experience and quality of the patient's care but also the health care provider's experience. They wouldn't have to be overworked to such an extent.
We think that this system will outperform the standard of care because [on paper] you more rapidly converge on the minimization of myocardial oxygen consumption and have better recovery during the hospital stay. So the patients have fewer readmissions and complications after being released. There's always some injury to the heart [with these cardiac events], and maybe, there may be some infarction of the heart. So we think that this level of care could reduce infarct size, so you preserve more of the heart, during treatment.
NL: And when you eventually hand off ACIS for clinical testing, what would the next project be?
JA: For us, the natural progression within the next 10 years, probably within the next five years, would be chronic heart failure. In chronic heart failure, you have to deal with more complexity, such as [tissue] remodeling, where the ventricles get thicker or get dilated. That kind of remodeling changes the mechanics.
You also have to deal with data from patients who are not in the hospital. We plan on building registries of patients [with Digital Twins] who would have been acutely ill to have access to that data for treating them outside. But then we have to also rely on things like wearable technologies, and we've been working on that as well. We have collaborations with folks at the Technical University of Munich who are developing special biosensors and biomaterials and implantable sensors and so forth that could help provide the data that would be important to doing predictive health maintenance in patients with chronic heart failure.
And in chronic heart failure, we have to deal with comorbidities and complications like kidney failure … and anemia. The combination of fluid overload and anemia all due to renal failure really makes the heart suffer from a lack of oxygen and causes slow deterioration.
I'm sure that complexity alone will keep me busy for the rest of my life. We have a lot of work to do with chronic heart failure; that would be next for sure.
Editor's note: This interview has been lightly edited for length and clarity.
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- <![CDATA[ Diagnostic dilemma quiz: Can you guess the diagnosis in these strange medical cases? ]]>
- Each week, Live Science highlights an interesting medical case report in its Diagnostic Dilemma series. We describe the patient and their symptoms, the testing and history-taking that revealed their diagnosis, their course of treatment and their ultimate health outcomes. We also highlight what makes the case unique, whether it's the rarity of the diagnosis, the unusual constellation of symptoms, or a novel therapeutic approach.
How many Diagnostic Dilemmas have you read — and can you guess the diagnosis? Take our quiz that draws from the cases we highlighted in 2025 and see if you can figure out each patient’s ailment. Tell us how you got on in the comments below.
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