physicsworld--2020-10-22--Optical microscopy –  how small can it go? - Physics World

“ Adorn ’ d with a curiously polish ’ d suit of sable [ black ] Armour ” and “ multitudes of sharp pinns , shap ’ d almost like Porcupine ’ s Quills ” .
While not quite how people would usually think of a flea , this was Robert Hooke ’ s description of the creature in his 1665 bestseller Micrographia .
The book contained images of flora and fauna minutiae drawn in mesmerizing detail , revealing familiar objects with unfamiliar features and structures that were not just inferred but actually seen with the help of a microscope @ @ @ @ @ @ @ gear change in the practice of science .
Microscopy has come a long way since the compound microscopes of the 17th century that Hooke used , where two convex lenses produced a magnified image .
As well as optical microscopy , which uses primarily visible light , we now have a host of other imaging techniques based on electrons , X-rays , atomic forces and other approaches besides .
Many of these achieve far greater resolutions than optical microscopy , so can this traditional technique ever catch up ?
What will then limit @ @ @ @ @ @ @ trying to improve something so old-fashioned ?
Even as other techniques were resolving atoms , optical microscopy retained a fan base because , in some ways , you could still see more optically .
When an object is illuminated with a pulse of light it can do a number of things with the energy .
The object can scatter , transmit or absorb the light , making molecules vibrate in different ways , exciting electrons into different orbitals or causing them to resonate in unison .
Spectral maps of what light does at @ @ @ @ @ @ @ about the chemical and structural composition of a sample , and its environment .
Other techniques might give a level of energy-dependent response , but optical spectra are especially rich .
Optical microscopy also means you don ’ t need to freeze samples , keep them in a vacuum or zap them with electrons and a massive electric field .
It ’ s therefore perfect for viewing living cells and other delicate samples .
Unfortunately , optical microscopy can only get you so far .
A virus like HIV is only 140 nm @ @ @ @ @ @ @ time anything smaller than a few hundred nanometres was considered beyond the scope of optical microscopy .
That meant you couldn ’ t use it to image , say , the distribution of proteins around a neuron or virus , leaving you without any insight into how these cells function , or how to stop them .
This assumption was not based on any practical limitations of the day ’ s microscope technology , but a fundamental physical restriction that limited the resolution of any optical microscope made from lenses .
When the @ @ @ @ @ @ @ a convex lens , it refracts – the ray paths bend toward each other .
This means that when the light hits your retina it ’ s as if the points were further away from each other .
To the mind ’ s eye the distance between them is magnified .
Armed with just such a simple single-lens based instrument – as well as a keen eye , pedantry for lighting and extraordinary patience – the Dutch drapers ’ son Antonie van Leeuwenhoek famously saw micro-organisms for the first time .
Writing in @ @ @ @ @ @ @ in 1673 , what he reported seeing were in fact bacteria and similar-sized micro-organisms , typically 0.5–5 μm ( so still several orders of magnitude larger than a virus ) .
When Hooke corroborated these observations , he used his more elaborate compound microscope – an instrument with an additional “ eyepiece ” lens that magnifies the already magnified image of the object produced by the first “ objective ” lens .
Compound microscopes can be powerful instruments and are widely used today , but they are still a long way off from @ @ @ @ @ @ @ the diffraction that occurs whenever light passes around an object or through an aperture .
Straight “ planar ” wave fronts are turned into curves that propagate like the rings round a pebble dropped in a pond .
Where these waves overlap they interfere – doubling up in peaks of light intensity or cancelling each other out in troughs .
A finite distance between resolvable objects emerges – any closer and the peaks overlap so they are indistinguishable .
In 1873 Ernst Abbe famously defined this “ diffraction-limited ” resolvable distance , d @ @ @ @ @ @ @ stone on his memorial in Jena , Germany : d > λ/2nsinϑ where λ is the wavelength of light and nsinϑ – known as the numerical aperture – is the product of the material ’ s relative refractive index and the sine of the half-angle of the maximum cone of light that can enter or exit the lens system .
In the decades that followed Abbe ’ s definition of the diffraction limit , the speed of light was found to be a constant , X-rays and radioactivity were discovered , energy and @ @ @ @ @ @ @ hypothesis muddied not just the distinction between waves and particles , but also the certainty of measurements of time and energy , and position and momentum , which became compromised .
All the while the diffraction limit has held – or at least it has for “ far-field ” light .
Light travels to our retinas as propagating electromagnetic waves – electric and magnetic fields leapfrogging each other through space .
This light is described as “ far-field ” by virtue of its having travelled far afield .
But every object that scatters @ @ @ @ @ @ @ near-field ” light clinging to its surface .
These are the higher-frequency , shorter-wavelength electromagnetic components that diminish to nothing within around a wavelength .
In 1928 the Irish physicist Edward Hutchinson Synge suggested that a device with an aperture placed within roughly a wavelength of an illuminated surface could detect the near-field light and generate images unrestricted by the diffraction limit .
The location of the near-field light interaction would be defined by the position of the aperture , and the resolution only limited by the aperture ’ s size .
Another @ @ @ @ @ @ @ , before Eric Ash and George Nicholls at University College London in the UK were able to beat the diffraction limit in this way .
They used microwaves with a wavelength of 3 cm , so a resolution of a centimetre was still breaking the diffraction limit .
But it would be another decade before anyone achieved near-field optical microscopy at visible wavelengths .
It was the 1980s and Dieter Pohl , a physicist who had worked on one of the first lasers in Europe as a graduate student , was employed at @ @ @ @ @ @ @ Gerd Binnig and Heini Rohrer had invented the scanning tunnelling microscope , which brought atomic-size features into view and stole much of the limelight from optical microscopy .
“ It bugged me a little that optical techniques were now discarded – at least at IBM – because of their limited resolution , ” Pohl recalls , despite having joined Binnig and Rohrer ’ s team .
While at IBM , Pohl conceived a scanning near-field optical microscope ( SNOM ) , realizing it with his then student Winfried Denk .
They did this @ @ @ @ @ @ @ but metal-coated quartz crystal – which they used as the aperture in Synge ’ s proposal – against a glass plate until a faint light transmitted from the near-field was detected .
Painstakingly maneouvring it within nanometres of the sample ( a test object with fine-line structures ) , Pohl and his colleagues were able to produce a SNOM image at visible wavelengths for the first time .
The resolution was 20 nm , much smaller than a lot of viruses .
Since then , SNOM has evolved from apertures in sheets to @ @ @ @ @ @ @ the tip ( figure 1a ) .
Light can travel down a SNOM tip and out of a nanoscale aperture at the end to illuminate a sample with near-field light , which is then reflected off or transmitted through the sample .
Once scattered , the light is detected as far-field .
Although diffraction limited , you know where this far-field light was scattered from ( the tip end ) so can still achieve nanometre-scale resolution .
In some systems the scattered light travels back up the tip to be detected there , @ @ @ @ @ @ @ light can come from a separate source .
There are now also apertureless tips ( figure 1b ) .
In these SNOM systems , an atomically sharp metal tip – much like those used in atomic force microscopy – is illuminated by a far-field light source and scanned within nanometres of a sample surface , causing the near-field light to scatter and therefore be detected as far-field light .
This method has the benefit of enhancing the field at the end of the tip .
The light causes resonant oscillations of the electrons @ @ @ @ @ @ @ ” – which concentrate and amplify the electromagnetic field in a highly localized area at the tip .
When this enhanced near-field scatters from the sample , the interactions are intensified , producing a much greater signal that allows you to image more clearly .
Anatoly Zayats , a nano-optical physicist at King ’ s College London in the UK , also thinks “ tipless ” SNOM is possible .
He works on structuring light beams with phenomena like “ superoscillations ” and “ photonic skyrmions ” , and suggests these may provide @ @ @ @ @ @ @ of the technique ’ s main bugbears – the indispensable yet pretty much irreproducible field enhancements from the tip that greatly depend on the individual tip ’ s shape and size .
“ Even minute differences in tip size and shape might have a significant impact on the resolution , ” says Zayats .
SNOM has become the workhorse for nanoscale chemical characterization , where optical spectra really give the edge over other techniques .
The field enhancements that help SNOM work have spawned progress in sensing , lithography and catalysis too .
@ @ @ @ @ @ @ it took 50 years for anyone to do anything with Synge ’ s idea from 1928 , especially as his paper contained a detailed description of how to realize the instrument .
Nanoscale fabrication and manipulation posed obvious challenges in the 1920s , but Zayats suggests that perhaps the most significant gap in available technology was signal collection and processing .
Not only do electronics and computers now collect , store and represent image data point by point with ease , but machine learning and artificial intelligence are pushing image-processing capabilities further still @ @ @ @ @ @ @ , 1928 may just not have been the right time for SNOM to take off .
“ The frontlines of physics were on quantum theory and the theory of general relativity , ” he says , “ not on such practical goals as a super-resolution imaging technique.
” SNOM works well on surfaces , but what about a virus deep in a tissue sample ?
Scientists have innovated with lens and focusing systems , and found ways to exploit the shorter wavelengths of X-rays , but even as late as the 1990s the @ @ @ @ @ @ @ .
Around this time , studies of fluorescing molecules were providing molecular biologists with new tools for imaging , albeit at diffraction-limited resolutions .
This set the scene for the development of a game-changing technique exploiting them .
“ What I realized is that it ’ s very hard to do anything about the focusing process itself , ” says Stefan Hell , one of the directors of the Max Planck Institute for Biophysical Chemistry in Göttingen , Germany .
“ But resolution is about making molecules discernible .
So the key to @ @ @ @ @ @ @ fluorescent molecule itself.
” In 1994 Hell proposed an approach for beating the diffraction limit in depth imaging based on fluorophores – molecules that can be excited to fluoresce by light at a specific wavelength but can also be suppressed from doing so with a different wavelength .
Using a standard round beam to excite molecules , overlaid with a doughnut-shaped beam to de-excite them , only those molecules at the very centre , where the intensity of the doughnut beam drops low enough , will actually fluoresce .
And because the doughnut @ @ @ @ @ @ @ the centre , that central region can have sub-diffraction-limit dimensions .
Hell ’ s experiments demonstrating “ stimulated emission and depletion ( STED ) microscopy ” , which he reported in 1999 , soon inspired others .
Keeping some of the molecules non-fluorescent , or working with fluorescence on–off switching using lasers with different wavelengths , turned out to be the key to “ fluorescence nanoscopy ” .
By 2006 reports of photo-activated localization microscopy ( PALM ) and stochastic optical reconstruction microscopy ( STORM ) were also raising eyebrows .
Developed by @ @ @ @ @ @ @ Institute in the US and William Moerner at Stanford University , also in the US , PALM and STORM are both stochastic approaches ( meaning they work with the probabilistic emission behaviour of fluorophores ) , but they differ in the types of fluorophores used .
They both flood the field of view with illumination at just enough intensity to switch one fluorophore on but keep the others dark .
You then need to find the emitting fluorophore with a camera and identify the centre of the molecule from the diffraction-limited intensity profile @ @ @ @ @ @ @ , there are no overlapping intensity profiles to confuse where the centre is .
In 2014 Hell , Betzig and Moerner were awarded the Nobel Prize for Chemistry for “ the development of super-resolved fluorescence microscopy ” .
However , although the techniques can resolve down to a few nanometres in theory , in practice the best they manage is a few tens of nanometres .
The problem is the need for more photons when you try to crank up the resolving power , whether that ’ s by getting as many photons @ @ @ @ @ @ @ PALM/STORM to increase the signal , or enlarging the region switching molecules off in STED .
“ That is limiting in terms of bleaching , ” explains Hell , referring to the process whereby overexposed fluorophores can no longer fluoresce .
Recognizing the problem , Hell combined the strengths of both STED and PALM/STORM in an approach termed MINFLUX , which tracks fluorophores with a doughnut beam that excites – rather than de-excites – fluorescence .
The technique homes in on an off-centre switched-on molecule by gauging its position from the measured intensity @ @ @ @ @ @ @ uses far fewer photons and generates images with 1–5 nm resolution in just tens of milliseconds , making it possible to create movies following dynamic processes .
“ I think it will open up a new field for microscopy , ” says Hell .
Imaging a structure like a virus with a resolution under 20 nm is now pretty routine in a lab setting , but optical microscopes remain bulky , complex devices .
In January 2017 , however , the EU launched a four-year project entitled ChipScope to design something less cumbersome @ @ @ @ @ @ @ advantages of SNOM with lensless optical microscopy , an existing technique that uses data analysis to generate images with a vastly expanded field of view based on multiple contributing images .
Conventional lensless microscopes hold a sample directly under the detectors and illuminate it from a sufficient distance , which optimizes the field of view .
In ChipScope , however , the sample is so close to an array of LEDs that non-diffracted near-field light illuminates it .
The intensity of light transmitted through the sample is then captured by a camera as @ @ @ @ @ @ @ up a shadow of the sample pixel by pixel , where each LED denotes a pixel .
Although the collected light is diffraction-limited , its origin is the lit LED , and that position is known .
As a result , the LED size , not the diffraction limit , determines the resolution .
Before ChipScope , the state of the art for tiny LEDs was around 100 μm .
Thanks to work at the University of Technology in Braunschweig , Germany , ChipScope has already demonstrated the approach with LEDs measuring 5 @ @ @ @ @ @ @ push the resolution lower with 200 nm LEDs .
Even with 200 nm LEDs ChipScope won ’ t break resolution records , and so far the device is capturing intensity alone , which means it can not be used for spectroscopy purposes .
It is also limited to very thin samples – a few hundred nanometres or less – so that enough light from a 200 nm LED can pass through and is not diffracted over the thickness of the sample .
But by stripping near-field optical imaging back to the bare bones @ @ @ @ @ @ @ size .
Angel Dieguez , from the University of Barcelona in Spain , who is ChipScope ’ s project co-ordinator , describes the device based on 5 μm LEDs as proof the concept works , at least in the far-field imaging regime .
“ The whole microscope is half the size of a phone , ” he highlights , “ making it two orders of magnitude more compact than a conventional microscope.
” By using 200 nm LEDs , the aim is to fit the device onto a chip that can slot into @ @ @ @ @ @ @ LEDs into a smooth array is no mean feat , however , and each LED needs its own wire for switching .
There is also the problem of how best to operate the microscope – either by moving the sample across the LEDs with microfluidics or moving the LEDs under the sample with microelectromechanical systems ( MEMS ) technology .
Then , somehow , you have to assemble the disparate components into a working device .
Earlier this year it seemed as if the researchers had built an array of 200 nm LEDs @ @ @ @ @ @ @ the device gathering dust in a lab as lockdown in Spain suspended further experiments .
Many will be watching developments when the lab is up and running again .
“ It ’ s interesting , ” says Hell , who is not involved in the ChipScope project himself .
“ Worth pursuing for sure.
” In the 450 years since Leeuwenhoek discovered bacteria with a single lens , countless ingenious scientific developments have shone a light on structures even smaller than viruses – in depth and even in motion .
So could a @ @ @ @ @ @ @ ’ s selfie craze ?
Who knows , but optical microscopy ’ s attraction is sure to endure .

Physics World. Members of the Institute of Physics can enjoy the full issue Taken from the October 2020 issue of. Members of the Institute of Physics can enjoy the full issue via the Physics World app
For centuries diffraction limited the resolution of optical microscopy. The past 50 years have, however, seen one limitation after another buckle under the ingenuity of a host of wide-ranging techniques, from lenses to tips, chips and doughnuts. Anna Demming reports
(Courtesy: Library of Congress, Rare Book and Special Collections Division / Science Photo Library)
“Adorn’d with a curiously polish’d suit of sable [black] Armour” and “multitudes of sharp pinns, shap’d almost like Porcupine’s Quills”. While not quite how people would usually think of a flea, this was Robert Hooke’s description of the creature in his 1665 bestseller Micrographia. The book contained images of flora and fauna minutiae drawn in mesmerizing detail, revealing familiar objects with unfamiliar features and structures that were not just inferred but actually seen with the help of a microscope. Hooke’s work represented a gear change in the practice of science.
Microscopy has come a long way since the compound microscopes of the 17th century that Hooke used, where two convex lenses produced a magnified image. As well as optical microscopy, which uses primarily visible light, we now have a host of other imaging techniques based on electrons, X-rays, atomic forces and other approaches besides. Many of these achieve far greater resolutions than optical microscopy, so can this traditional technique ever catch up? What will then limit its scope, and why even bother trying to improve something so old-fashioned?
Even as other techniques were resolving atoms, optical microscopy retained a fan base because, in some ways, you could still see more optically. When an object is illuminated with a pulse of light it can do a number of things with the energy. The object can scatter, transmit or absorb the light, making molecules vibrate in different ways, exciting electrons into different orbitals or causing them to resonate in unison. Spectral maps of what light does at different wavelengths therefore give researchers vital information about the chemical and structural composition of a sample, and its environment. Other techniques might give a level of energy-dependent response, but optical spectra are especially rich.
Optical microscopy also means you don’t need to freeze samples, keep them in a vacuum or zap them with electrons and a massive electric field. It’s therefore perfect for viewing living cells and other delicate samples.
Unfortunately, optical microscopy can only get you so far. A virus like HIV is only 140 nm in size, but for a long time anything smaller than a few hundred nanometres was considered beyond the scope of optical microscopy. That meant you couldn’t use it to image, say, the distribution of proteins around a neuron or virus, leaving you without any insight into how these cells function, or how to stop them. This assumption was not based on any practical limitations of the day’s microscope technology, but a fundamental physical restriction that limited the resolution of any optical microscope made from lenses.
Where it all began Antonie van Leeuwenhoek used this instrument to see micro-organisms for the first time in 1673. (Courtesy: Ann Ronan Picture Library / Heritage Images / Science Photo Library)
Lenses and limits
When the light from two separate points passes through a convex lens, it refracts – the ray paths bend toward each other. This means that when the light hits your retina it’s as if the points were further away from each other. To the mind’s eye the distance between them is magnified. Armed with just such a simple single-lens based instrument – as well as a keen eye, pedantry for lighting and extraordinary patience – the Dutch drapers’ son Antonie van Leeuwenhoek famously saw micro-organisms for the first time.
Writing in the Philosophical Transactions of the Royal Society in 1673, what he reported seeing were in fact bacteria and similar-sized micro-organisms, typically 0.5–5 μm (so still several orders of magnitude larger than a virus). When Hooke corroborated these observations, he used his more elaborate compound microscope – an instrument with an additional “eyepiece” lens that magnifies the already magnified image of the object produced by the first “objective” lens. Compound microscopes can be powerful instruments and are widely used today, but they are still a long way off from resolving a virus.
The snag is the diffraction that occurs whenever light passes around an object or through an aperture. Straight “planar” wave fronts are turned into curves that propagate like the rings round a pebble dropped in a pond. Where these waves overlap they interfere – doubling up in peaks of light intensity or cancelling each other out in troughs. A finite distance between resolvable objects emerges – any closer and the peaks overlap so they are indistinguishable. In 1873 Ernst Abbe famously defined this “diffraction-limited” resolvable distance, d, in a relation now carved in stone on his memorial in Jena, Germany: d > λ/2nsinϑ where λ is the wavelength of light and nsinϑ – known as the numerical aperture – is the product of the material’s relative refractive index and the sine of the half-angle of the maximum cone of light that can enter or exit the lens system.
In the decades that followed Abbe’s definition of the diffraction limit, the speed of light was found to be a constant, X-rays and radioactivity were discovered, energy and matter proved equivalent, and the quantum hypothesis muddied not just the distinction between waves and particles, but also the certainty of measurements of time and energy, and position and momentum, which became compromised. All the while the diffraction limit has held – or at least it has for “far-field” light.
Close up Scanning near-field optical microscopy (SNOM) image of a fixed endothelial HLMVEC cell, taken in four parts. The scale bar represents 3 μm. (Courtesy: J. Bio. 10.1002/jbio.201600081. Reused with permission of John Wiley & Sons)
Beyond Abbe’s limit
Light travels to our retinas as propagating electromagnetic waves – electric and magnetic fields leapfrogging each other through space. This light is described as “far-field” by virtue of its having travelled far afield. But every object that scatters or emits far-field light also has “near-field” light clinging to its surface. These are the higher-frequency, shorter-wavelength electromagnetic components that diminish to nothing within around a wavelength.
In 1928 the Irish physicist Edward Hutchinson Synge suggested that a device with an aperture placed within roughly a wavelength of an illuminated surface could detect the near-field light and generate images unrestricted by the diffraction limit. The location of the near-field light interaction would be defined by the position of the aperture, and the resolution only limited by the aperture’s size. Another 44 years was to pass, however, before Eric Ash and George Nicholls at University College London in the UK were able to beat the diffraction limit in this way. They used microwaves with a wavelength of 3 cm, so a resolution of a centimetre was still breaking the diffraction limit. But it would be another decade before anyone achieved near-field optical microscopy at visible wavelengths.
It was the 1980s and Dieter Pohl, a physicist who had worked on one of the first lasers in Europe as a graduate student, was employed at IBM. At that time his colleagues Gerd Binnig and Heini Rohrer had invented the scanning tunnelling microscope, which brought atomic-size features into view and stole much of the limelight from optical microscopy. “It bugged me a little that optical techniques were now discarded – at least at IBM – because of their limited resolution,” Pohl recalls, despite having joined Binnig and Rohrer’s team.
While at IBM, Pohl conceived a scanning near-field optical microscope (SNOM), realizing it with his then student Winfried Denk. They did this by pressing a corner of a transparent but metal-coated quartz crystal – which they used as the aperture in Synge’s proposal – against a glass plate until a faint light transmitted from the near-field was detected. Painstakingly maneouvring it within nanometres of the sample (a test object with fine-line structures), Pohl and his colleagues were able to produce a SNOM image at visible wavelengths for the first time. The resolution was 20 nm, much smaller than a lot of viruses.
Since then, SNOM has evolved from apertures in sheets to metal-coated probes that have an aperture at the tip (figure 1a). Light can travel down a SNOM tip and out of a nanoscale aperture at the end to illuminate a sample with near-field light, which is then reflected off or transmitted through the sample. Once scattered, the light is detected as far-field. Although diffraction limited, you know where this far-field light was scattered from (the tip end) so can still achieve nanometre-scale resolution. In some systems the scattered light travels back up the tip to be detected there, and in this mode the original illuminating light can come from a separate source.
There are now also apertureless tips (figure 1b). In these SNOM systems, an atomically sharp metal tip – much like those used in atomic force microscopy – is illuminated by a far-field light source and scanned within nanometres of a sample surface, causing the near-field light to scatter and therefore be detected as far-field light. This method has the benefit of enhancing the field at the end of the tip. The light causes resonant oscillations of the electrons on the probe surface – “plasmons” – which concentrate and amplify the electromagnetic field in a highly localized area at the tip. When this enhanced near-field scatters from the sample, the interactions are intensified, producing a much greater signal that allows you to image more clearly.
1 The tip of the technique Scanning near-field optical microscopy (SNOM) can feature a tip with (a) or without (b) an aperture. Both rely on scattering near-field light at a sample’s surface and then detecting it as far-field light. Apertureless SNOM can achieve a greater resolution because the atomically sharp tip creates a localized enhanced electromagnetic field, which increases the imaging signal.
Anatoly Zayats, a nano-optical physicist at King’s College London in the UK, also thinks “tipless” SNOM is possible. He works on structuring light beams with phenomena like “superoscillations” and “photonic skyrmions”, and suggests these may provide a tip-free alternative that gets around one of the technique’s main bugbears – the indispensable yet pretty much irreproducible field enhancements from the tip that greatly depend on the individual tip’s shape and size. “Even minute differences in tip size and shape might have a significant impact on the resolution,” says Zayats.
SNOM has become the workhorse for nanoscale chemical characterization, where optical spectra really give the edge over other techniques. The field enhancements that help SNOM work have spawned progress in sensing, lithography and catalysis too. Given the success you might wonder why it took 50 years for anyone to do anything with Synge’s idea from 1928, especially as his paper contained a detailed description of how to realize the instrument. Nanoscale fabrication and manipulation posed obvious challenges in the 1920s, but Zayats suggests that perhaps the most significant gap in available technology was signal collection and processing. Not only do electronics and computers now collect, store and represent image data point by point with ease, but machine learning and artificial intelligence are pushing image-processing capabilities further still. In addition, as Pohl suggests, 1928 may just not have been the right time for SNOM to take off. “The frontlines of physics were on quantum theory and the theory of general relativity,” he says, “not on such practical goals as a super-resolution imaging technique.”
Going deep
SNOM works well on surfaces, but what about a virus deep in a tissue sample? Scientists have innovated with lens and focusing systems, and found ways to exploit the shorter wavelengths of X-rays, but even as late as the 1990s the diffraction limit still held for depth imaging.
Around this time, studies of fluorescing molecules were providing molecular biologists with new tools for imaging, albeit at diffraction-limited resolutions. This set the scene for the development of a game-changing technique exploiting them. “What I realized is that it’s very hard to do anything about the focusing process itself,” says Stefan Hell, one of the directors of the Max Planck Institute for Biophysical Chemistry in Göttingen, Germany. “But resolution is about making molecules discernible. So the key to overcoming the barrier was held by the fluorescent molecule itself.”
In 1994 Hell proposed an approach for beating the diffraction limit in depth imaging based on fluorophores – molecules that can be excited to fluoresce by light at a specific wavelength but can also be suppressed from doing so with a different wavelength. Using a standard round beam to excite molecules, overlaid with a doughnut-shaped beam to de-excite them, only those molecules at the very centre, where the intensity of the doughnut beam drops low enough, will actually fluoresce. And because the doughnut beam’s intensity drops gradually towards the centre, that central region can have sub-diffraction-limit dimensions.
Hell’s experiments demonstrating “stimulated emission and depletion (STED) microscopy”, which he reported in 1999, soon inspired others. Keeping some of the molecules non-fluorescent, or working with fluorescence on–off switching using lasers with different wavelengths, turned out to be the key to “fluorescence nanoscopy”. By 2006 reports of photo-activated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM) were also raising eyebrows. Developed by Eric Betzig at the Howard Hughes Medical Institute in the US and William Moerner at Stanford University, also in the US, PALM and STORM are both stochastic approaches (meaning they work with the probabilistic emission behaviour of fluorophores), but they differ in the types of fluorophores used. They both flood the field of view with illumination at just enough intensity to switch one fluorophore on but keep the others dark. You then need to find the emitting fluorophore with a camera and identify the centre of the molecule from the diffraction-limited intensity profile recorded. With only one molecule excited, there are no overlapping intensity profiles to confuse where the centre is.
In 2014 Hell, Betzig and Moerner were awarded the Nobel Prize for Chemistry for “the development of super-resolved fluorescence microscopy”. However, although the techniques can resolve down to a few nanometres in theory, in practice the best they manage is a few tens of nanometres. The problem is the need for more photons when you try to crank up the resolving power, whether that’s by getting as many photons as possible from the emitting fluorophore in PALM/STORM to increase the signal, or enlarging the region switching molecules off in STED. “That is limiting in terms of bleaching,” explains Hell, referring to the process whereby overexposed fluorophores can no longer fluoresce.
Recognizing the problem, Hell combined the strengths of both STED and PALM/STORM in an approach termed MINFLUX, which tracks fluorophores with a doughnut beam that excites – rather than de-excites – fluorescence. The technique homes in on an off-centre switched-on molecule by gauging its position from the measured intensity and the expected intensity profile. It uses far fewer photons and generates images with 1–5 nm resolution in just tens of milliseconds, making it possible to create movies following dynamic processes. “I think it will open up a new field for microscopy,” says Hell.
2 Combined technique A 3D MINFLUX recording of a mitochondrian labelling Mic60 (orange) and ATPB (blue) proteins. To keep acquisition times as short as possible, only the region close to the mitochondrion was imaged. MINFLUX was developed by Stefan Hell. (CC BY PNAS 117 20607)
Pocket near-field optics
Imaging a structure like a virus with a resolution under 20 nm is now pretty routine in a lab setting, but optical microscopes remain bulky, complex devices. In January 2017, however, the EU launched a four-year project entitled ChipScope to design something less cumbersome.
The idea combines some of the advantages of SNOM with lensless optical microscopy, an existing technique that uses data analysis to generate images with a vastly expanded field of view based on multiple contributing images. Conventional lensless microscopes hold a sample directly under the detectors and illuminate it from a sufficient distance, which optimizes the field of view. In ChipScope, however, the sample is so close to an array of LEDs that non-diffracted near-field light illuminates it. The intensity of light transmitted through the sample is then captured by a camera as each LED is lit, to build up a shadow of the sample pixel by pixel, where each LED denotes a pixel. Although the collected light is diffraction-limited, its origin is the lit LED, and that position is known. As a result, the LED size, not the diffraction limit, determines the resolution. Before ChipScope, the state of the art for tiny LEDs was around 100 μm. Thanks to work at the University of Technology in Braunschweig, Germany, ChipScope has already demonstrated the approach with LEDs measuring 5 μm, and the plan is to push the resolution lower with 200 nm LEDs.
Light from a chip ChipScope’s new compact optical microscope relies on tiny LEDs that illuminate the sample and determine the resolution. (Courtesy: ChipScope)
Even with 200 nm LEDs ChipScope won’t break resolution records, and so far the device is capturing intensity alone, which means it cannot be used for spectroscopy purposes. It is also limited to very thin samples – a few hundred nanometres or less – so that enough light from a 200 nm LED can pass through and is not diffracted over the thickness of the sample. But by stripping near-field optical imaging back to the bare bones, ChipScope makes huge gains in device size. Angel Dieguez, from the University of Barcelona in Spain, who is ChipScope’s project co-ordinator, describes the device based on 5 μm LEDs as proof the concept works, at least in the far-field imaging regime. “The whole microscope is half the size of a phone,” he highlights, “making it two orders of magnitude more compact than a conventional microscope.” By using 200 nm LEDs, the aim is to fit the device onto a chip that can slot into a mobile phone.
Etching 200 nm LEDs into a smooth array is no mean feat, however, and each LED needs its own wire for switching. There is also the problem of how best to operate the microscope – either by moving the sample across the LEDs with microfluidics or moving the LEDs under the sample with microelectromechanical systems (MEMS) technology. Then, somehow, you have to assemble the disparate components into a working device. Earlier this year it seemed as if the researchers had built an array of 200 nm LEDs, but the COVID-19 pandemic led to the device gathering dust in a lab as lockdown in Spain suspended further experiments. Many will be watching developments when the lab is up and running again. “It’s interesting,” says Hell, who is not involved in the ChipScope project himself. “Worth pursuing for sure.”
In the 450 years since Leeuwenhoek discovered bacteria with a single lens, countless ingenious scientific developments have shone a light on structures even smaller than viruses – in depth and even in motion. So could a fascination with phone-based nanoscopy finally subvert today’s selfie craze? Who knows, but optical microscopy’s attraction is sure to endure.


physicsworld--2020-10-23--ASTRO Annual Meeting highlights radiation oncology innovation - Physics World

The ASTRO Annual Meeting is the world ’ s largest scientific meeting on radiation oncology .
And like many conferences and other events around the globe , this year ’ s meeting has gone entirely virtual .
Billed as “ a virtual experience unlike any other ” , the 2020 ASTRO Annual Meeting includes live and pre-recorded education and scientific presentations , many with live Q & A sessions , as well as breakout rooms for networking , chat and product demonstrations .
The theme of this year ’ s meeting is “ global oncology : radiation therapy in a @ @ @ @ @ @ @ president Thomas Eichler , the primary focus will be on global cancer issues , with expert analysis , fireside chats and TED style presentations .
The meeting will also include information regarding the impact of the coronavirus pandemic on healthcare professionals and patients .
This year ’ s meeting also incorporates a cutting-edge Virtual Exhibit Hall .
This highly interactive online environment allows attendees to visit exhibitors , learn about their products and services , and chat with booth representatives .
It also includes industry expert theatres and industry satellite symposia , where @ @ @ @ @ @ @ treatment options on the horizon and how these will impact patient care .
Here ’ s a selection of some of the innovations on show at the 2020 ASTRO Annual Meeting .
Quality assurance ( QA ) plays a fundamental role in any radiotherapy procedure .
IBA Dosimetry is working to shape QA to advance patient safety in radiation therapy , proton therapy and medical imaging .
The company predicts that its latest innovations will bring the accuracy and efficiency of QA to a new level .
Future solutions , meanwhile , will @ @ @ @ @ @ @ the medical physics workload .
Independent QA is essential to ensure reliable , trustworthy and accurate QA , and has been assumed as a given in the radiotherapy community .
But as radiotherapy systems increasingly offer built-in “ self-check ” QA , the need for independent QA becomes imperative .
To raise awareness of this topic , IBA Dosimetry has teamed with radiotherapy QA equipment vendors worldwide to launch an “ Independent Quality Assurance ” initiative .
IBA Dosimetry also highlights the need for convergence of machine and patient QA .
Today , @ @ @ @ @ @ @ and those for verifying the patient-specific plan generally have little or no connectivity .
Combining data from patient QA and machine QA will provide more precise outcomes and faster results .
These QA innovations are based on four strategic pillars – implementation of measurements , integration , smart automation and prediction of QA results – that help save valuable time of the medical physicist and provide higher accuracy and increased confidence .
IBA Dosimetry notes that while measurements will remain important for future QA , further integration , Monte Carlo-based predictive QA and @ @ @ @ @ @ @ where it really matters , leading to fewer measurements with better quality results .
With the advancement of radiotherapy techniques designed to escalate delivered tumour doses , there is an increasing need for quality assurance tools ( QA ) in radiation treatment planning .
Medical physicists are looking to improve treatment delivery by optimizing current 4D image-guided radiotherapy ( IGRT ) protocols and exploring rapidly advancing adaptive techniques .
Modus QA specializes in high-quality radiotherapy QA phantoms , including end-to-end QA solutions for 4D IGRT .
Designed by medical physicists and built based @ @ @ @ @ @ @ s product range includes targeting QA phantoms , motion QA phantoms , as well as geometric distortion devices for MR-guided radiotherapy and 3D dosimetry systems .
In this on-demand presentation , End-to-end motion QA in radiation therapy treatment planning , Rocco Flores provides an overview of the company ’ s CT and MR-safe motion phantoms , with an emphasis on how the phantoms can meet current and future QA needs .
Flores , a product manager at Modus QA , discusses 4D IGRT , explaining the need to reduce treatment volumes and the @ @ @ @ @ @ @ He goes on to describe how the company ’ s motion QA phantoms can be used to provide end-to-end QA of CT-based and MRI-based treatment systems .
For too long , radiation therapy quality assurance ( QA ) has required multiple databases and manual processes to get the job done .
Fragmentation with no automation makes working at home harder than it needs to be .
Sun Nuclear ’ s SunCHECK Platform solves this .
SunCHECK aggregates disparate databases , automates inefficient tasks and centralizes critical patient and machine data to provide easier @ @ @ @ @ @ @ a worklist-oriented dashboard , remote development of tests , as well as real-time results via direct device connectivity , automated data transfer and analysis .
Over 800 centres worldwide have adopted SunCHECK .
Many users report that the platform has proved essential to their operational continuity through the COVID-19 pandemic .
SunCHECK ’ s remote access helps minimize time in the clinic , for example , while automation reduces reliance on physical tools .
To assist more departments with solving their own remote QA challenges , Sun Nuclear offers flexible options for SunCHECK @ @ @ @ @ @ @ at sunnuclear.com .
• Sun Nuclear is hosting a session entitled “ Performing QA remotely in the age of COVID ” at the 2020 ASTRO Annual Meeting , in the Innovation Hub .
Presented by Jason Tracy , a medical physicist at Sun Nuclear , the session will take place on 26 October at 11.45 EST .
When hypofractionated radiotherapy is delivered via stereotactic body radiation therapy ( SBRT ) , a strict adherence to dose–volume constraints to the surrounding at-risk organs is paramount .
Specifically , the steep dose gradients associated with @ @ @ @ @ @ @ reliability during the entire treatment delivery process .
The RayPilot HypoCath from Micropos Medical is designed to enhance the precision of prostate cancer SBRT .
The system is a removable electromagnetic tracking device that enables real-time localization of the prostate during both conventional and hypofractionated radiotherapy .
With the transmitter integrated in a standard Foley catheter , RayPilot HypoCath may offer better localization of the prostate and its motion ( for accurate treatment ) and helps outline the urethra .
It can be used with conventional linacs and requires no surgical intervention .
@ @ @ @ @ @ @ prostate cancer : Biology Meets Technology , describes the first clinical experience using the RayPilot HypoCath at Ospedale San Gererdo in Monza , Italy .
The hospital started SBRT treatment of prostate cancer patients using RayPilot HypoCath in June .
In the white paper , head of the clinic Stefano Arcangeli describes how the tracking device fits into precision radiation treatment of prostate cancer .
Stereotactic Radiosurgery ( SRS ) necessitates a high degree of accuracy in target localization and dose delivery .
With this in mind , CIRS offers the Stereotactic End-to-End @ @ @ @ @ @ @ provides a means to check all necessary steps of a treatment planning system – from diagnostic imaging with CT , MR and PET , through to plan verification .
STEEV ’ s anthropomorphic exterior enables the use of clinical positioning and fixation .
The phantom ’ s internal details – such as cortical and trabecular bone , brain , spinal cord , teeth , sinuses and trachea – provide a realistic clinical simulation , enabling end-to-end testing of SRS systems in the most challenging anatomical regions .
Geometric and organic target inserts enable @ @ @ @ @ @ @ , geometric machine QA and treatment planning system QA .
STEEV accommodates five interchangeable multi-modality inserts , which come with a variety of internal targets and are filled with MRI- or PET-compatible liquids .
Five external MRI/CT fiducials enable additional alignment and distortion evaluation .
The phantom can also accommodate a variety of tissue-equivalent inserts suitable for small-field dosimetry .
CT is an invaluable tool when treating cancer with radiation therapy .
Studies have shown that CT is increasingly used in tumour volume estimation , with image quality critical to the accuracy and @ @ @ @ @ @ @ Analogic have joined forces to offer healthcare providers an innovative CT system that enables new workflows in oncology imaging and treatment , while seamlessly executing diagnostic radiology requirements for all body types .
With a unique 85 cm bore and 64-/128-slice performance , the Persona CT is a revolutionary CT system that helps to simplify oncology treatment planning .
The Persona CT ’ s large bore adds comfort for patients of any size .
Fast acquisition further enhances the patient experience , while easy operation improves workflow , speed and accuracy .
The @ @ @ @ @ @ @ synchronized dose-lowering acquisition technologies .
Meanwhile , its low-noise acquisition system and refined image processing with artificial intelligence deliver exceptional image quality .
Finally , the Persona CT offers advanced applications powered by Fujifilm ’ s Synapse 3D software , as well as specialized 3D tools for coronary , brain , respiratory , orthopaedics and whole-body applications .
ExacTrac Dynamic is the next-generation patient positioning and monitoring system from Brainlab .
The new system offers never-before-seen , high-speed thermal surface tracking technology combined with an update of ExacTrac X-ray monitoring .
For thermal @ @ @ @ @ @ @ a highly accurate and reliable hybrid thermal surface by correlating the patient ’ s heat signature to their reconstructed 3D surface structure .
To achieve this , 300,000 3D surface points are acquired and matched to the heat signal generated by the thermal camera , creating another dimension to track their position .
The X-ray monitoring system includes larger ( compared with ExacTrac 6.5 or 6.2 ) panels that show more anatomy for easier orientation and interpretation of X-ray images , while improved soft-tissue contrast and enhanced read-out speed prevent motion blurring effects @ @ @ @ @ @ @ X-ray tubes supports more automated , high-frequency imaging .
New clinical workflows allow for treatment of a wide array of indications .
Together , these advancements make ExacTrac Dynamic the all-in-one radiotherapy tracking solution .
Join Brainlab on 26 October at 11.00 EST for a virtual session discussing the first clinical applications of ExacTrac Dynamic .
The session will cover topics including : The MRgRT Motion Management QA phantom from CIRS is designed to address the quality assurance ( QA ) needs of MR-guided radiotherapy .
The phantom is MR-safe due to the @ @ @ @ @ @ @ .
The two piezoelectric motors move a cylindrical insert , which contains a tracking target , through a gel/liquid-fillable body by rotating it independently from the motion in the inferior–superior direction .
The moving insert contains a “ tumour ” target filled with gel , surrounded by the same background gel used to fill the “ body ” .
This body includes simulated lungs , liver , kidney and spine , providing a heterogeneous background .
The simulated organs are filled with gels that provide CT and MR contrast versus the background gel @ @ @ @ @ @ @ lungs ) also offer ion chamber dosimetry cavities , enabling completion of the entire QA process : from imaging to planning to verification of the delivered dose .
The phantom is driven by CIRS Motion Control software , which offers multiple built-in motion profiles for commissioning and routine QA , as well as allowing import of complex patient-specific respiratory waveforms .
It can also set up independently controllable waveforms for the insert ’ s linear and rotational motion .
To enable verification of beam latency , the inferior–superior motion of the insert/moving target @ @ @ @ @ @ @

Over 100 companies are exhibiting their products and services at the 2020 ASTRO Annual Meeting. (Courtesy: Fujifilm)
The ASTRO Annual Meeting is the world’s largest scientific meeting on radiation oncology. And like many conferences and other events around the globe, this year’s meeting has gone entirely virtual. Billed as “a virtual experience unlike any other”, the 2020 ASTRO Annual Meeting includes live and pre-recorded education and scientific presentations, many with live Q&A sessions, as well as breakout rooms for networking, chat and product demonstrations.
The theme of this year’s meeting is “global oncology: radiation therapy in a changing world”. According to ASTRO president Thomas Eichler, the primary focus will be on global cancer issues, with expert analysis, fireside chats and TED style presentations. The meeting will also include information regarding the impact of the coronavirus pandemic on healthcare professionals and patients.
This year’s meeting also incorporates a cutting-edge Virtual Exhibit Hall. This highly interactive online environment allows attendees to visit exhibitors, learn about their products and services, and chat with booth representatives. It also includes industry expert theatres and industry satellite symposia, where attendees can find out about trends and treatment options on the horizon and how these will impact patient care. Here’s a selection of some of the innovations on show at the 2020 ASTRO Annual Meeting.
Innovating and evolving radiotherapy quality assurance
Quality assurance (QA) plays a fundamental role in any radiotherapy procedure. IBA Dosimetry is working to shape QA to advance patient safety in radiation therapy, proton therapy and medical imaging. The company predicts that its latest innovations will bring the accuracy and efficiency of QA to a new level. Future solutions, meanwhile, will significantly reduce QA times and further streamline the medical physics workload.
Independent QA is essential to ensure reliable, trustworthy and accurate QA, and has been assumed as a given in the radiotherapy community. But as radiotherapy systems increasingly offer built-in “self-check” QA, the need for independent QA becomes imperative. To raise awareness of this topic, IBA Dosimetry has teamed with radiotherapy QA equipment vendors worldwide to launch an “Independent Quality Assurance” initiative.
Convergence of machine QA and patient QA will unlock the potential of real risk-based radiotherapy QA. (Courtesy: IBA Dosimetry)
IBA Dosimetry also highlights the need for convergence of machine and patient QA. Today, QA applications for validating the treatment machine and those for verifying the patient-specific plan generally have little or no connectivity. Combining data from patient QA and machine QA will provide more precise outcomes and faster results.
These QA innovations are based on four strategic pillars – implementation of measurements, integration, smart automation and prediction of QA results – that help save valuable time of the medical physicist and provide higher accuracy and increased confidence. IBA Dosimetry notes that while measurements will remain important for future QA, further integration, Monte Carlo-based predictive QA and automation will enable users to measure only where it really matters, leading to fewer measurements with better quality results.
IBA Dosimetry’s QA innovation strategy is based on four pillars: measure, integrate, automate and predict. (Courtesy: IBA Dosimetry)
Motion phantoms provide end-to-end radiotherapy QA
With the advancement of radiotherapy techniques designed to escalate delivered tumour doses, there is an increasing need for quality assurance tools (QA) in radiation treatment planning. Medical physicists are looking to improve treatment delivery by optimizing current 4D image-guided radiotherapy (IGRT) protocols and exploring rapidly advancing adaptive techniques.
Modus QA specializes in high-quality radiotherapy QA phantoms, including end-to-end QA solutions for 4D IGRT. Designed by medical physicists and built based on clinical needs, the company’s product range includes targeting QA phantoms, motion QA phantoms, as well as geometric distortion devices for MR-guided radiotherapy and 3D dosimetry systems.
Modus QA offers a range of motion QA phantoms for MR-guided radiotherapy and respiratory motion simulation. (Courtesy: Modus QA)
In this on-demand presentation, End-to-end motion QA in radiation therapy treatment planning, Rocco Flores provides an overview of the company’s CT and MR-safe motion phantoms, with an emphasis on how the phantoms can meet current and future QA needs. Flores, a product manager at Modus QA, discusses 4D IGRT, explaining the need to reduce treatment volumes and the methods used to mitigate patient motion. He goes on to describe how the company’s motion QA phantoms can be used to provide end-to-end QA of CT-based and MRI-based treatment systems.
SunCHECK Platform optimizes remote QA
For too long, radiation therapy quality assurance (QA) has required multiple databases and manual processes to get the job done. Fragmentation with no automation makes working at home harder than it needs to be. Sun Nuclear’s SunCHECK Platform solves this.
On-site or at home, SunCHECK users can perform QA in the same way. (Courtesy: Sun Nuclear)
SunCHECK aggregates disparate databases, automates inefficient tasks and centralizes critical patient and machine data to provide easier access by staff. The platform delivers a worklist-oriented dashboard, remote development of tests, as well as real-time results via direct device connectivity, automated data transfer and analysis.
Over 800 centres worldwide have adopted SunCHECK. Many users report that the platform has proved essential to their operational continuity through the COVID-19 pandemic. SunCHECK’s remote access helps minimize time in the clinic, for example, while automation reduces reliance on physical tools.
Patient QA and machine QA information are presented in a single interface. (Courtesy: Sun Nuclear)
To assist more departments with solving their own remote QA challenges, Sun Nuclear offers flexible options for SunCHECK Platform acquisition. Demonstrations can be scheduled at sunnuclear.com.
Sun Nuclear is hosting a session entitled “Performing QA remotely in the age of COVID” at the 2020 ASTRO Annual Meeting, in the Innovation Hub. Presented by Jason Tracy, a medical physicist at Sun Nuclear, the session will take place on 26 October at 11.45 EST.
SBRT for localized prostate cancer: Biology Meets Technology
When hypofractionated radiotherapy is delivered via stereotactic body radiation therapy (SBRT), a strict adherence to dose–volume constraints to the surrounding at-risk organs is paramount. Specifically, the steep dose gradients associated with SBRT plans require a high level of reliability during the entire treatment delivery process.
The RayPilot HypoCath offers real-time prostate tracking, without surgical intervention. (Courtesy: Micropos Medical)
The RayPilot HypoCath from Micropos Medical is designed to enhance the precision of prostate cancer SBRT. The system is a removable electromagnetic tracking device that enables real-time localization of the prostate during both conventional and hypofractionated radiotherapy. With the transmitter integrated in a standard Foley catheter, RayPilot HypoCath may offer better localization of the prostate and its motion (for accurate treatment) and helps outline the urethra. It can be used with conventional linacs and requires no surgical intervention.
The white paper, SBRT for localized prostate cancer: Biology Meets Technology, describes the first clinical experience using the RayPilot HypoCath at Ospedale San Gererdo in Monza, Italy. The hospital started SBRT treatment of prostate cancer patients using RayPilot HypoCath in June. In the white paper, head of the clinic Stefano Arcangeli describes how the tracking device fits into precision radiation treatment of prostate cancer.
STEEV phantom enables end-to-end testing of SRS systems
Stereotactic Radiosurgery (SRS) necessitates a high degree of accuracy in target localization and dose delivery. With this in mind, CIRS offers the Stereotactic End-to-End Verification (STEEV) phantom, which provides a means to check all necessary steps of a treatment planning system – from diagnostic imaging with CT, MR and PET, through to plan verification.
The STEEV phantom (left) and a CT image of the phantom with the 038-13 insert. (Courtesy: CIRS)
STEEV’s anthropomorphic exterior enables the use of clinical positioning and fixation. The phantom’s internal details – such as cortical and trabecular bone, brain, spinal cord, teeth, sinuses and trachea – provide a realistic clinical simulation, enabling end-to-end testing of SRS systems in the most challenging anatomical regions. Geometric and organic target inserts enable comprehensive image quality assurance (QA), geometric machine QA and treatment planning system QA.
STEEV accommodates five interchangeable multi-modality inserts, which come with a variety of internal targets and are filled with MRI- or PET-compatible liquids. Five external MRI/CT fiducials enable additional alignment and distortion evaluation. The phantom can also accommodate a variety of tissue-equivalent inserts suitable for small-field dosimetry.
Persona CT streamlines radiology and oncology treatment planning
CT is an invaluable tool when treating cancer with radiation therapy. Studies have shown that CT is increasingly used in tumour volume estimation, with image quality critical to the accuracy and ease of treatment planning.
The Persona CT system offers advanced imaging with high precision, accuracy and reliability. (Courtesy: Fujifilm)
Fujifilm and Analogic have joined forces to offer healthcare providers an innovative CT system that enables new workflows in oncology imaging and treatment, while seamlessly executing diagnostic radiology requirements for all body types. With a unique 85 cm bore and 64-/128-slice performance, the Persona CT is a revolutionary CT system that helps to simplify oncology treatment planning.
The Persona CT’s large bore adds comfort for patients of any size. Fast acquisition further enhances the patient experience, while easy operation improves workflow, speed and accuracy. The scanner offers advanced automated dose optimization and synchronized dose-lowering acquisition technologies. Meanwhile, its low-noise acquisition system and refined image processing with artificial intelligence deliver exceptional image quality.
Finally, the Persona CT offers advanced applications powered by Fujifilm’s Synapse 3D software, as well as specialized 3D tools for coronary, brain, respiratory, orthopaedics and whole-body applications.
ExacTrac Dynamic patient positioning system merges surface and X-ray tracking
ExacTrac Dynamic is the next-generation patient positioning and monitoring system from Brainlab. The new system offers never-before-seen, high-speed thermal surface tracking technology combined with an update of ExacTrac X-ray monitoring.
ExacTrac Dynamic combines cutting-edge tracking technologies to achieve radiotherapy positioning and monitoring with submillimetre accuracy. (Courtesy: Brainlab)
For thermal tracking, the 4D thermal camera creates a highly accurate and reliable hybrid thermal surface by correlating the patient’s heat signature to their reconstructed 3D surface structure. To achieve this, 300,000 3D surface points are acquired and matched to the heat signal generated by the thermal camera, creating another dimension to track their position.
The X-ray monitoring system includes larger (compared with ExacTrac 6.5 or 6.2) panels that show more anatomy for easier orientation and interpretation of X-ray images, while improved soft-tissue contrast and enhanced read-out speed prevent motion blurring effects. The higher heat capacity of the X-ray tubes supports more automated, high-frequency imaging. New clinical workflows allow for treatment of a wide array of indications. Together, these advancements make ExacTrac Dynamic the all-in-one radiotherapy tracking solution.
Join Brainlab on 26 October at 11.00 EST for a virtual session discussing the first clinical applications of ExacTrac Dynamic. The session will cover topics including:
Radiosurgical planning: brain and spine disease considerations.
IGRS experience: intra-cranial tumours and spine metastasis setups.
Radiotherapy planning: breast disease considerations.
IGRT experience: free-breathing and manual breath-hold breast setups.
MR-safe QA phantom focuses on MR-guided radiotherapy
The MRgRT Motion Management QA phantom from CIRS is designed to address the quality assurance (QA) needs of MR-guided radiotherapy. The phantom is MR-safe due to the use of piezoelectric motors and non-ferromagnetic materials. The two piezoelectric motors move a cylindrical insert, which contains a tracking target, through a gel/liquid-fillable body by rotating it independently from the motion in the inferior–superior direction.
The MRgRT Motion Management QA phantom (left) and an MR image of the phantom. (Courtesy: CIRS)
The moving insert contains a “tumour” target filled with gel, surrounded by the same background gel used to fill the “body”. This body includes simulated lungs, liver, kidney and spine, providing a heterogeneous background. The simulated organs are filled with gels that provide CT and MR contrast versus the background gel. All organs (except for the lungs) also offer ion chamber dosimetry cavities, enabling completion of the entire QA process: from imaging to planning to verification of the delivered dose.
The phantom is driven by CIRS Motion Control software, which offers multiple built-in motion profiles for commissioning and routine QA, as well as allowing import of complex patient-specific respiratory waveforms. It can also set up independently controllable waveforms for the insert’s linear and rotational motion. To enable verification of beam latency, the inferior–superior motion of the insert/moving target can be gated based on amplitude.


physicsworld--2020-10-23--White papers: RaySearch Laboratories highlights advances in radiation oncology software - Physics Wo

White papers: RaySearch Laboratories highlights advances in radiation oncology software - Physics World

The content highlighted in this article has been created and hosted by Physics World ’ s corporate partners .
It is free to read but you will be asked to share your contact details with the relevant partner first before being granted access immediately afterwards .
This time we are featuring white papers , case studies and a webinar from RaySearch Laboratories .
The machine learning planning module in RayStation* can generate one or multiple deliverable treatment plans in just minutes .
The automated treatment planning method learns from historical patient and plan data , and infers a 3D spatial @ @ @ @ @ @ @ This new approach to planning can improve efficiency , reduce treatment plan variability and facilitate knowledge sharing .
The white paper , Machine learning automated treatment planning , introduces RayStation ’ s machine learning planning module and describes a clinical study on head-and-neck cancer cases conducted at University Medical Center Groningen .
Provision CARES Proton Therapy in Nashville , USA , is the first clinic to connect the oncology information system RayCare* directly to the treatment delivery system , using it to record and verify the treatment sessions .
In 2018 , Provision @ @ @ @ @ @ @ use RaySearch software exclusively .
In the case study , Optimizing the patient journey with RayCare , the Provision team describe their experience of using RayCare and how the system meets the clinic ’ s specific needs .
High-quality contours of anatomical structures are a vital aspect of radiation therapy , but the process of manually delineating regions-of-interest is time-consuming and suffers from inter- and intra-practitioner variability .
With the automatic tools in RayStation , this process can be greatly simplified .
The latest technique is deep-learning segmentation , which is able to @ @ @ @ @ @ @ and still automatically generate contours of all relevant regions-of-interests in under a minute .
This approach , described in the white paper Deep-learning segmentation , provides a highly powerful tool for patient modelling in RayStation .
University Medical Center Groningen ( UMCG ) has teamed up with RaySearch to evaluate the first fully automated machine learning framework for generating robust treatment plans .
The case study , Automated robust planning for IMPT in HN cancer using machine learning , describes the use of machine learning to create robust intensity modulated proton ( IMPT @ @ @ @ @ @ @ The robust machine learning planning framework* will be clinically available in the RayStation 10B release in December 2020 .
Treatment planning for radiation therapy inevitably involves compromises between dose to the tumour volume and sparing of healthy structures .
These trade-offs are conventionally handled using trial and error , where parameters such as objective function weights are adjusted and the treatment plan is reoptimized multiple times .
Manual parameter tuning is inefficient , and the quality of the result dependent upon the experience and skill of the treatment planner .
The white paper @ @ @ @ @ @ @ of multi-criteria optimization ( MCO ) in treatment planning to provides a more streamlined and intuitive workflow .
With MCO , the clinical plan is selected by continuous navigation over the set of possible plans , enabling clinicians to make informed and structured treatment decisions .
Information systems at hospitals support the collection and communication of everything from patient tracking to billing information and treatment history .
Commonly , there are multiple information systems , which should seamlessly communicate with each other to support efficient and safe care by avoiding manual transfer of @ @ @ @ @ @ @ oncology information system is designed for integration with external healthcare information systems , such as EPIC .
The white paper , RayCare connectivity , explores the integration of RayCare between hospital information systems to support a complete view of the patient ’ s data for clinicians .
Finally , RaySearch presents the webinar Machine learning in radiation oncology .
In this virtual product unveiling for ESTRO 2020 , Fredrik Löfman and the machine learning team at RaySearch discuss machine learning , including the deep learning segmentation application , machine learning planning and a @ @ @ @ @ @ @ innovation , RayIntelligence .
*Subject to regulatory clearance in some markets .

The content highlighted in this article has been created and hosted by Physics World’s corporate partners. It is free to read but you will be asked to share your contact details with the relevant partner first before being granted access immediately afterwards.
Welcome to the latest in a new series of sponsored articles showcasing some of the latest white papers and webinars from physics-based businesses around the world
This time we are featuring white papers, case studies and a webinar from RaySearch Laboratories.
The machine learning planning module in RayStation* can generate one or multiple deliverable treatment plans in just minutes. The automated treatment planning method learns from historical patient and plan data, and infers a 3D spatial dose on a new patient geometry. This new approach to planning can improve efficiency, reduce treatment plan variability and facilitate knowledge sharing. The white paper, Machine learning automated treatment planning, introduces RayStation’s machine learning planning module and describes a clinical study on head-and-neck cancer cases conducted at University Medical Center Groningen.
Provision CARES Proton Therapy in Nashville, USA, is the first clinic to connect the oncology information system RayCare* directly to the treatment delivery system, using it to record and verify the treatment sessions. In 2018, Provision also became the first clinic worldwide to use RaySearch software exclusively. In the case study, Optimizing the patient journey with RayCare, the Provision team describe their experience of using RayCare and how the system meets the clinic’s specific needs.
High-quality contours of anatomical structures are a vital aspect of radiation therapy, but the process of manually delineating regions-of-interest is time-consuming and suffers from inter- and intra-practitioner variability. With the automatic tools in RayStation, this process can be greatly simplified. The latest technique is deep-learning segmentation, which is able to learn from an unlimited number of patients and still automatically generate contours of all relevant regions-of-interests in under a minute. This approach, described in the white paper Deep-learning segmentation, provides a highly powerful tool for patient modelling in RayStation.
University Medical Center Groningen (UMCG) has teamed up with RaySearch to evaluate the first fully automated machine learning framework for generating robust treatment plans. The case study, Automated robust planning for IMPT in HN cancer using machine learning, describes the use of machine learning to create robust intensity modulated proton (IMPT) plans for oropharyngeal cancer patients. The robust machine learning planning framework* will be clinically available in the RayStation 10B release in December 2020.
Treatment planning for radiation therapy inevitably involves compromises between dose to the tumour volume and sparing of healthy structures. These trade-offs are conventionally handled using trial and error, where parameters such as objective function weights are adjusted and the treatment plan is reoptimized multiple times. Manual parameter tuning is inefficient, and the quality of the result dependent upon the experience and skill of the treatment planner. The white paper Multi-criteria optimization in RayStation introduces the use of multi-criteria optimization (MCO) in treatment planning to provides a more streamlined and intuitive workflow. With MCO, the clinical plan is selected by continuous navigation over the set of possible plans, enabling clinicians to make informed and structured treatment decisions.
Information systems at hospitals support the collection and communication of everything from patient tracking to billing information and treatment history. Commonly, there are multiple information systems, which should seamlessly communicate with each other to support efficient and safe care by avoiding manual transfer of data between hospital systems. The RayCare oncology information system is designed for integration with external healthcare information systems, such as EPIC. The white paper, RayCare connectivity, explores the integration of RayCare between hospital information systems to support a complete view of the patient’s data for clinicians.
Finally, RaySearch presents the webinar Machine learning in radiation oncology. In this virtual product unveiling for ESTRO 2020, Fredrik Löfman and the machine learning team at RaySearch discuss machine learning, including the deep learning segmentation application, machine learning planning and a brief introduction to RaySearch’s latest innovation, RayIntelligence.
*Subject to regulatory clearance in some markets.


physicsworld--2020-10-23--Diamond microscope probes magnetism in 2D materials - Physics World

Magnetism in two-dimensional materials is difficult to characterize because the materials ’ extreme thinness renders conventional techniques ineffective .
Researchers in Australia , Russia and China have now used a new method called wide-field nitrogen-vacancy ( NV ) microscopy to measure the magnetic strength of vanadium triiodide ( VI ) , a 2D material that is known to be strongly ferromagnetic in its bulk , 3D form .
The technique could also be used to study other 2D magnetic materials – including some possible building blocks for future energy-efficient electronic devices .
An NV microscope is a recently-developed instrument that @ @ @ @ @ @ @ of weak magnetic fields .
It is particularly well-suited for analysing samples of van der Waals materials ( that is , materials composed of atomically thin layers that interact with each other via weak van der Waals forces ) because it enables researchers to image magnetic domains ( microscopic regions in which all magnetic moments point in the same direction ) in individual flakes of the material with sub-micron resolution .
In the present study , researchers led by Lloyd Hollenberg of the University of Melbourne used an NV microscope made from a @ @ @ @ @ @ @ defects .
These defects are known as NV centres , and they occur when adjacent carbon atoms in the diamond lattice are replaced with a nitrogen atom and an empty lattice site .
The nitrogen has an extra electron that remains unpaired , and therefore behaves as an isolated spin that can be up , down or a superposition of the two .
The state of this spin can be probed by illuminating the diamond with laser light and recording the intensity and “ spin-active ” frequencies of the fluorescence emitted .
Because @ @ @ @ @ @ @ surroundings , the spin state of their electrons is not immediately affected by surrounding thermal fluctuations .
They can therefore be used to detect the very weak magnetic fields stemming from nearby electronic or nuclear spins – making them highly sensitive probes of magnetic resonance , capable of monitoring local spin changes in a material over distances of a few tens of nanometres .
In their experiments , Hollenberg and colleagues placed their sample of VI on top of the NV microscope ’ s defect layer , excited the NV centres with a @ @ @ @ @ @ @ the resulting fluorescence .
By sweeping the frequency of an applied microwave field across the sample ( which they placed in a cryostat so that they could repeat the measurements at temperatures ranging from 4 to 300 K ) , they obtained what is known as an optically-detected magnetic resonance spectrum for their sample .
When the researchers applied a magnetic field of 0.5 to 1 Tesla perpendicular to their samples ( the +z direction ) at a temperature of 5 K , they observed complete and abrupt switching of the magnetic field @ @ @ @ @ @ @ intermediate partially-reversed state .
This ferromagnetism persists down to two atomic layers , while the switching remains abrupt up to 50 K , which is VI ’ s Curie temperature ( that is , the temperature at which the bulk material loses its permanent magnetism ) .
In hard magnetic materials like VI , the direction-switching process depends on one of two mechanisms : nucleation or pinning of domain walls .
In bulk materials , these mechanisms can normally be distinguished by their initial magnetization curves .
These curves are produced by placing @ @ @ @ @ @ @ a magnetic field and measuring how its magnetization increases .
In a nucleation-type magnet , the domain walls move freely .
In a pinning-type magnet , as the name suggests , they are constantly being trapped .
To determine which type of mechanism was at play in ultrathin VI , Hollenberg and colleagues applied short magnetic pulses ( around 10 nanoseconds long ) in the -z direction to samples that had initially been magnetized in the +z direction and imaged the magnetization in a low magnet field after each pulse .
The results @ @ @ @ @ @ @ nucleation-type hard ferromagnet .
However , the researchers also found that the magnetic strength of 2D VI is roughly half that of its 3D counterpart .
“ This was a bit of a surprise , and we are currently trying to understand why the magnetisation is weaker in 2D , which will be important for applications , ” says team member Jean-Philippe Tetienne .
According to Artem Oganov of the Skolkovo Institute of Science and Technology in Moscow , the group ’ s work could lead to new technologies .
“ Just a @ @ @ @ @ @ @ two-dimensional-magnets are possible at all , ” says Oganov , who was also part of the research team .
“ With the discovery of two-dimensional ferromagnetic VI , a new exciting class of materials emerged .
New classes of material always mean that new technologies will appear , both for studying such materials and harnessing their properties.
” Members of the team , who include researchers from the University of Basel , RMIT University , Nanjing University of Posts and Telecommunications , Moscow Institute of Physics and Technology , Northwestern Polytechnical University , @ @ @ @ @ @ @ they now plan to use their NV microscope to study other 2D magnetic materials .
They report their work in Advanced Materials .

New diamond-based nano-microscope opens up potential for 2D materials. (Courtesy: David A Broadway)
Magnetism in two-dimensional materials is difficult to characterize because the materials’ extreme thinness renders conventional techniques ineffective. Researchers in Australia, Russia and China have now used a new method called wide-field nitrogen-vacancy (NV) microscopy to measure the magnetic strength of vanadium triiodide (VI 3 ), a 2D material that is known to be strongly ferromagnetic in its bulk, 3D form. The technique could also be used to study other 2D magnetic materials – including some possible building blocks for future energy-efficient electronic devices.
An NV microscope is a recently-developed instrument that uses defects in diamond as sensitive probes of weak magnetic fields. It is particularly well-suited for analysing samples of van der Waals materials (that is, materials composed of atomically thin layers that interact with each other via weak van der Waals forces) because it enables researchers to image magnetic domains (microscopic regions in which all magnetic moments point in the same direction) in individual flakes of the material with sub-micron resolution.
NV centres as detectors of weak magnetic fields
In the present study, researchers led by Lloyd Hollenberg of the University of Melbourne used an NV microscope made from a diamond substrate with a surface layer of defects. These defects are known as NV centres, and they occur when adjacent carbon atoms in the diamond lattice are replaced with a nitrogen atom and an empty lattice site. The nitrogen has an extra electron that remains unpaired, and therefore behaves as an isolated spin that can be up, down or a superposition of the two. The state of this spin can be probed by illuminating the diamond with laser light and recording the intensity and “spin-active” frequencies of the fluorescence emitted.
Because NV centres are naturally isolated from their surroundings, the spin state of their electrons is not immediately affected by surrounding thermal fluctuations. They can therefore be used to detect the very weak magnetic fields stemming from nearby electronic or nuclear spins – making them highly sensitive probes of magnetic resonance, capable of monitoring local spin changes in a material over distances of a few tens of nanometres.
Measuring magnetic field behaviour
In their experiments, Hollenberg and colleagues placed their sample of VI 3 on top of the NV microscope’s defect layer, excited the NV centres with a laser and used a camera to image the resulting fluorescence. By sweeping the frequency of an applied microwave field across the sample (which they placed in a cryostat so that they could repeat the measurements at temperatures ranging from 4 to 300 K), they obtained what is known as an optically-detected magnetic resonance spectrum for their sample.
When the researchers applied a magnetic field of 0.5 to 1 Tesla perpendicular to their samples (the +z direction) at a temperature of 5 K, they observed complete and abrupt switching of the magnetic field direction in most flakes, with no intermediate partially-reversed state. This ferromagnetism persists down to two atomic layers, while the switching remains abrupt up to 50 K, which is VI 3 ’s Curie temperature (that is, the temperature at which the bulk material loses its permanent magnetism).
VI 3 is a nucleation-type hard ferromagnet
In hard magnetic materials like VI 3 , the direction-switching process depends on one of two mechanisms: nucleation or pinning of domain walls. In bulk materials, these mechanisms can normally be distinguished by their initial magnetization curves. These curves are produced by placing a sample of a magnetic material in a magnetic field and measuring how its magnetization increases.
In a nucleation-type magnet, the domain walls move freely. In a pinning-type magnet, as the name suggests, they are constantly being trapped. To determine which type of mechanism was at play in ultrathin VI 3 , Hollenberg and colleagues applied short magnetic pulses (around 10 nanoseconds long) in the -z direction to samples that had initially been magnetized in the +z direction and imaged the magnetization in a low magnet field after each pulse.
The results obtained suggest that ultrathin VI 3 is a nucleation-type hard ferromagnet. However, the researchers also found that the magnetic strength of 2D VI 3 is roughly half that of its 3D counterpart. “This was a bit of a surprise, and we are currently trying to understand why the magnetisation is weaker in 2D, which will be important for applications,” says team member Jean-Philippe Tetienne.
According to Artem Oganov of the Skolkovo Institute of Science and Technology in Moscow, the group’s work could lead to new technologies. “Just a few years ago, scientists doubted that two-dimensional-magnets are possible at all,” says Oganov, who was also part of the research team. “With the discovery of two-dimensional ferromagnetic VI 3 , a new exciting class of materials emerged. New classes of material always mean that new technologies will appear, both for studying such materials and harnessing their properties.”
Members of the team, who include researchers from the University of Basel, RMIT University, Nanjing University of Posts and Telecommunications, Moscow Institute of Physics and Technology, Northwestern Polytechnical University, and Renmin University of China, say they now plan to use their NV microscope to study other 2D magnetic materials. They report their work in Advanced Materials.


physicsworld--2020-10-23--Physics in the pandemic: “Moving the International Physicists’ Tournament online was challenging” -

Physics in the pandemic: “Moving the International Physicists’ Tournament online was challenging” - Physics World

David Collomb is a PhD student at the University of Bath , UK , and is organiser of the International Physicists ’ Tournament This post is part of a series on how the COVID-19 pandemic is affecting the personal and professional lives of physicists around the world .
If you ’ d like to share your own perspective , please contact us at pwld @ ioppublishing.org .
The International Physicists ’ Tournament ( IPT ) is a global competition designed to test the problem-solving and presentation skills of undergraduate students interested in physics .
Following the same format as the @ @ @ @ @ @ @ ) for secondary schools , the IPT involves teams of up to six undergraduates spending nine months solving up to 17 challenging , open-ended and unsolved problems in physics .
The tournament winner is traditionally crowned at a week-long event that takes place at a different location each year .
Previous hosts have included famous institutions such as the Moscow Institute of Physics and Technology ( MIPT ) in Russia , the École Polytechnique Fédérale de Lausanne ( EPFL ) in Switzerland , and Chalmers University of Technology in Sweden .
This year @ @ @ @ @ @ @ be the twelfth ever final , things panned out rather differently .
As with many scientific events , conferences , seminars and trade fairs , it was increasingly looking likely that the IPT would have to moved online due to global restrictions designed to combat the spread of COVID-19 .
And so it was , that after much deliberation on how the pandemic will evolve , the executive team of the IPT decided to replace the physical event with a two-day , online tournament on the weekend of 26-27 September 2020 .
The @ @ @ @ @ @ @ “ physics fights ” .
At the start of each , one team serves as “ reporter ” , with an other as “ opponent ” , and a third holds acting as “ reviewer ” .
The reporter is challenged by the opponent to present their work on one of the problems .
Once presented , the opponent then has to constructively critique the reporter ’ s work .
A debate ensues in which the two teams , with guidance from the reviewer , aim to improve upon the approach proposed by @ @ @ @ @ @ @ , the roles switch and the process repeats until each team has held all roles .
A panel of judges grades each role , giving marks out of 10 .
After a series of fights , the top three teams proceed to a final .
Moving the tournament online was challenging .
Time zones were the first major hurdle , with participants stretching from Columbia to China ( a huge 13-hour difference ) .
We ended up altering the rules to ensure all teams could participate at reasonable times .
We did this @ @ @ @ @ @ @ qualifying fights ( apart from the final ) , which drastically cut the times of each fight .
To allow students from across the world to mingle and mix — one of the unique features of the tournament — we also introduced extra activities and opportunities , including the IPT ’ s first-ever photo competition .
It allowed participants to share their creativity and team comradery through submitted photos on social media .
A total of 10 teams took part in the tournament this year , each taking part in three qualifying fights @ @ @ @ @ @ @ race looked close with just eight points separating all teams in the top half of the table .
It was only after the final fight that the top three teams – MIPT ( Russia ) , Kharkiv Karazin National University ( Ukraine ) and Rice University ( US ) – emerged .
Rice was one of two teams to appear for the first time in the tournament , the other being from SNS NUST in Islamabad , Pakistan .
The final itself , which you can watch on You Tube , was a @ @ @ @ @ @ @ and the Ukraine , with only three points out of a total possible 60 separating them after the three rounds .
Viewers were treated to a presentation by the You Tube science communicator Bruce Yeany , who gave his thoughts on some of the problems he had presented and investigated himself in the past .
In a tense final few moments , the Russian team emerged as the overall winner .
The tournament , however , didn ’ t end on the Sunday .
Recognising that some teams hadn ’ t been able @ @ @ @ @ @ @ to COVID-19 , the executive committee decided to hold three days of presentations in a traditional conference format .
This allowed teams to present solutions that hadn ’ t been challenged in the tournament , while also giving an opportunity to teams that hadn ’ t been able to take part at all , such as those from Brazil and Poland , to show the fruits of their labours .
The pandemic is one of the strongest challenges faced so far in many of our lives , with much of our ordinary day-to-day @ @ @ @ @ @ @ on shaky grounds .
However , the online IPT revealed the strengths of our ability to innovate and bring people together in the midst of isolation , adding much welcome streams of positivity for physics students across the world .
I would like to give special thanks on behalf of the executive committee to all the participants who took part and presented high quality solutions , and to our jury who volunteered their weekend to provide valuable feedback to the students .
Anyone interested in taking part in future events is welcome to @ @ @ @ @ @ @ .

David Collomb is a PhD student at the University of Bath, UK, and is organizer of the International Physicists’ Tournament This post is part of a series on how the COVID-19 pandemic is affecting the personal and professional lives of physicists around the world. If you’d like to share your own perspective, please contact us at pwld@ioppublishing.org.
The International Physicists’ Tournament (IPT) is a global competition designed to test the problem-solving and presentation skills of undergraduate students interested in physics. Following the same format as the International Young Physicists’ Tournament (IYPT) for secondary schools, the IPT involves teams of up to six undergraduates spending nine months solving up to 17 challenging, open-ended and unsolved problems in physics.
The tournament winner is traditionally crowned at a week-long event that takes place at a different location each year. Previous hosts have included famous institutions such as the Moscow Institute of Physics and Technology (MIPT) in Russia, the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, and Chalmers University of Technology in Sweden. This year, however, which was meant to be the twelfth ever final, things panned out rather differently.
Online challenge
As with many scientific events, conferences, seminars and trade fairs, it was increasingly looking likely that the IPT would have to moved online due to global restrictions designed to combat the spread of COVID-19. And so it was, that after much deliberation on how the pandemic will evolve, the executive team of the IPT decided to replace the physical event with a two-day, online tournament on the weekend of 26–27 September 2020.
The tournament usually consists of a series of “physics fights”
The tournament usually consists of a series of “physics fights”. At the start of each, one team serves as “reporter”, with an other as “opponent”, and a third holds acting as “reviewer”. The reporter is challenged by the opponent to present their work on one of the problems. Once presented, the opponent then has to constructively critique the reporter’s work.
A debate ensues in which the two teams, with guidance from the reviewer, aim to improve upon the approach proposed by the reporter. After the first round, the roles switch and the process repeats until each team has held all roles. A panel of judges grades each role, giving marks out of 10. After a series of fights, the top three teams proceed to a final.
A tense affair
Moving the tournament online was challenging. Time zones were the first major hurdle, with participants stretching from Columbia to China (a huge 13-hour difference). We ended up altering the rules to ensure all teams could participate at reasonable times. We did this by removing the reviewer role for all qualifying fights (apart from the final), which drastically cut the times of each fight.
To allow students from across the world to mingle and mix – one of the unique features of the tournament – we also introduced extra activities and opportunities, including the IPT’s first photo competition. It allowed participants to share their creativity and team camaraderie through submitted photos on social media.
A total of 10 teams took part in the tournament this year, each taking part in three qualifying fights. After the first two, the race looked close with just eight points separating all teams in the top half of the table. It was only after the final fight that the top three teams – MIPT (Russia), Kharkiv Karazin National University (Ukraine) and Rice University (US) – emerged. Rice was one of two teams to appear for the first time in the tournament, the other being from SNS NUST in Islamabad, Pakistan.
The final itself, which you can watch on YouTube, was a tense affair between the teams from Russia and the Ukraine, with only three points out of a total possible 60 separating them after the three rounds. Viewers were treated to a presentation by the YouTube science communicator Bruce Yeany, who gave his thoughts on some of the problems he had presented and investigated himself in the past. In a tense final few moments, the Russian team emerged as the overall winner.
Don’t stop us now
The tournament, however, didn’t end on the Sunday. Recognizing that some teams hadn’t been able to hunt for solutions since March due to COVID-19, the executive committee decided to hold three days of presentations in a traditional conference format. This allowed teams to present solutions that hadn’t been challenged in the tournament, while also giving an opportunity to teams that hadn’t been able to take part at all, such as those from Brazil and Poland, to show the fruits of their labours.
The pandemic is one of the strongest challenges faced so far in many of our lives, with much of our ordinary day-to-day happenings being rattled and our future placed on shaky grounds. However, the online IPT revealed the strengths of our ability to innovate and bring people together in the midst of isolation, adding much welcome streams of positivity for physics students across the world.
I would like to give special thanks on behalf of the executive committee to all the participants who took part and presented high quality solutions, and to our jury who volunteered their weekend to provide valuable feedback to the students. Anyone interested in taking part in future events is welcome to contact the executive committee via this link.


physicsworld--2020-10-23--Payload competition on a SpaceX Falcon 9, chicken nugget and 4G network also head into space - Physi

Payload competition on a SpaceX Falcon 9, chicken nugget and 4G network also head into space - Physics World

You learn something new every day , goes the old adage – and today was no exception as I gleaned two nuggets of information from the UK-based frozen food retailer Iceland .
One is that the chicken nugget was invented in the 1950s by scientists at Cornell University and the other is that Iceland is the biggest seller of chicken nuggets in the UK .
To celebrate their market dominance and the 50th anniversary of the chain , Iceland has sent a chicken nugget into space .
The morsel was suspended from a balloon and launched from a location in @ @ @ @ @ @ @ km .
You can watch its ascent in the above video but being in Wales in October , the view of the Earth is quickly obscured by clouds .
Speaking of sending stuff into space , UK and New Zealand-based Orbital Astronautics has launched two competitions to encourage people to design and build spacecraft payloads .
Orbital Start-up is aimed at start-up companies and Orbital Student is aimed at , you guessed it , students .
In both cases entries will be judged by industry experts and the top start-up and the two @ @ @ @ @ @ @ an Orbital Astronautics satellite and launched into orbit on a SpaceX Falcon 9 .
The deadline for entries is 15 December .
Not wanting to be upstaged by Iceland or Orbital Astronautics , NASA and Nokia are joining forces to put a 4G mobile phone network on the Moon .
Described as “ ultra-compact , low-power and space-hardened , ” the Guardian reports that the lunar network will be part of NASA ’ s plan to establish a long-term human presence on the moon by 2030 .
The network will be installed remotely @ @ @ @ @ @ @ by US based Intuitive Machines and will be used for navigation and streaming video .
The deal is worth $ 14.1m to Nokia ’ s US subsidiary .

You learn something new every day, goes the old adage – and today was no exception as I gleaned two nuggets of information from the UK-based frozen food retailer Iceland. One is that the chicken nugget was invented in the 1950s by scientists at Cornell University and the other is that Iceland is the biggest seller of chicken nuggets in the UK. To celebrate their market dominance and the 50th anniversary of the chain, Iceland has sent a chicken nugget into space. The morsel was suspended from a balloon and launched from a location in Wales, reaching an altitude of 33.5 km. You can watch its ascent in the above video but being in Wales in October, the view of the Earth is quickly obscured by clouds.
Speaking of sending stuff into space, UK and New Zealand-based Orbital Astronautics has launched two competitions to encourage people to design and build spacecraft payloads. Orbital Start-up is aimed at start-up companies and Orbital Student is aimed at, you guessed it, students. In both cases entries will be judged by industry experts and the top start-up and the two top student entries will be integrated within an Orbital Astronautics satellite and launched into orbit on a SpaceX Falcon 9. The deadline for entries is 15 December.
Not wanting to be upstaged by Iceland or Orbital Astronautics, NASA and Nokia are joining forces to put a 4G mobile phone network on the Moon. Described as “ultra-compact, low-power and space-hardened,” the Guardian reports that the lunar network will be part of NASA’s plan to establish a long-term human presence on the moon by 2030.
The network will be installed remotely using a “lunar hopper” built by US based Intuitive Machines and will be used for navigation and streaming video. The deal is worth $14.1m to Nokia’s US subsidiary.