Resurrecting dinosaurs with medical scanners and 3D printers

CT scans and 3D printers are making it possible to see fossils that were previously inaccessible inside rock.

Accurate copies of fossilised bones can now be made from the combined use of computed tomography (CT) scans and 3D printers, according to a paper published in the journal Radiology.

The technique offers scientists a non-destructive way of transporting and handling rare or fragile fossils.

To protect such specimens from damage during transportation, the fossils are often stored in plaster jackets or casts. These jackets must be strong enough to protect the fossils, but should also separate easily from the specimen when removed.

It is during the removal of the plaster and surrounding sediment that the fossil is in danger of material loss or even destruction. This typically occurs when the plaster is stuck fast to the bone.

(A 3D print of a fossil (right) next to the original still inside a plaster jacket. Image: Courtesy of Radiology and RSNA)

A group of German researchers found that, by using CT and 3D printers, they could separate fossilised bone from its surrounding sediment matrix in a way that would not harm the specimen, then produce a 3D copy of it.

Applying this method to an unidentified fossil from the Museum für Naturkunde in Berlin, the researchers scanned the bone with a 320-slice multi-detector system to show up the different attenuation (absorption of radiation) through the bone and the surrounding sediment matrix, depicting clearly the fossilised vertebra.

The scan also provided information on the condition and integrity of the specimen, like otherwise unknown fractures, and helped the researchers build an accurate reconstruction of the fossil.

Then using a laser sintering system – a process which uses high-powered lasers to fuse materials by adding thin horizontal layers of plastic – an accurate 3D copy of the fossil was produced.

(An enlarged 3D copy of a 380 million year old coelacanth skull found near Fitzroy Crossing, Western Australia. Image: John Long)

The impact on palaeontology
According to Richard Brian Gunderman, a professor of radiology at Indiana University who was not involved in the study, CT scanners are able to determine the exact structural dimensions of an object, down to fractions of a millimetre.

This data can then be used to construct a replica so precise that objects of great historical interest, like Stradivarius violins, have been created to sound remarkably similar to the originals.

“Such a technology has been a boon to palaeontologists in the past few years,” said John Long, strategic professor in palaeontology at Flinders University.

“Once we relied on meticulous time-consuming methods to prepare delicate fossils out of the rock and, even then, we could only see their external features. Now, using high-resolution micro-CT scanners and synchrotrons [particle accelerators], we can investigate every nook and cranny of the fossil right down to individual cells and tissue structures without having to risk damaging the specimen.

“Combined with advanced 3D printing, we can now slice though the ancient fossil skulls and print them in halves showing the full anatomy in clear definition. This will no doubt revitalise palaeontology.”

(A 3D scan of a 380 million-year-old Gogonasus fish skull by Tim Senden and ANU Vizlab.)

Ahi Sema Issever, from the Charité Campus Mitte in Berlin and one of the study’s authors, explained: “The most important benefit of this method is that it is non-destructive so the risk of harming the fossil is minimal. In addition, not only does this method allow for a global exchange of rare fossils in any quantity, data on the specimens can also be digitally shared between research institutes, museums and schools while protecting the original fossil.”

Darren Curnoe, associate professor at the University of New South Wales, agreed, saying: “Famous fossils like the Taung Child in South Africa - the very first ancient ape-like creature found in our human evolutionary tree - has been quite badly damaged following almost 90 years of study by scientists.

“Almost everyone who sees the fossil wants to take a couple of measurements of their own, and by doing so, is damaging these priceless pieces of our collective heritage. We need to do better, and such technology might just be the answer.”

A note of caution
Although supportive of the technological breakthrough in this study, Professor Long warned that researchers must not rely too heavily on tomographic imagery and 3D printing to draw their conclusions.

“It is important to carefully study the preservational biases of the original fossil first to determine how reliable a computer-generated image will be. In some cases, replacement of bone by other minerals or the presence of solid inclusions can effect the quality of CT images and affect 3D printing results.

“Scientists still need to study the original specimens in detail first, and then make interpretations using CT tomography and 3D printing.”

(A scanned 400 million-year-old placoderm eye capsule found in Taemas near Canberra. Image: Tim Senden)

Associate Professor Curnoe agreed, saying: “Any model made from CT scans must properly distinguish actual bone from missing bone, or even from materials like plaster, that had been used in the past to reconstruct missing bones in the fossils. This is particularly important since most fossils found are incomplete or distorted.

“In the end, there is nothing like seeing the real thing to fully understand the anatomy and the state of preservation of a fossil. But, for the sort of work many scientists do, especially postgraduate students, 3D models would be incredibly useful at a time when funding can be very hard to get.”

Beyond fossils
Some experts speculate that the findings from this study will benefit the medical field, like building and fitting implants in orthopaedic surgery. Others feel that the technique could be used to model real bones and other tissues, such as cadavers that have been preserved in ice or peat bogs.

Martin Baumers, a research fellow at the University of Nottingham, would like to see the implementation of a virtual library and data infrastructure for such 3D data and designs. He believes that it would aid collaborative research, allowing experts from different disciplines to share and retrieve 3D models for 3D printing or other scientific, even commercial, usage.

For Professor Long, the biggest breakthrough will come when palaeontologists possess the ability to make portable machines to take into the field and scan fossils, still buried under the rock layers, to determine the full extent of the fossil before excavating it.

This article was originally published at The Conversation. Read the original article.The Conversation

A scan of a 380million-year-old tooth from a fossil shark. (Image: Tim Sendon)
Cleveland police
Show Hide image

Should Facebook face the heat for the Cleveland shooting video?

On Easter Sunday, a man now dubbed the “Facebook killer” shot and killed a grandfather before uploading footage of the murder to the social network. 

A murder suspect has committed suicide after he shot dead a grandfather seemingly at random last Sunday. Steve Stephens (pictured above), 37, was being hunted by police after he was suspected of killing Robert Godwin, 74, in Cleveland, Ohio.

The story has made international headlines not because of the murder in itself – in America, there are 12,000 gun homicides a year – but because a video of the shooting was uploaded to Facebook by the suspected killer, along with, moments later, a live-streamed confession.

After it emerged that Facebook took two hours to remove the footage of the shooting, the social network has come under fire and has promised to “do better” to make the site a “safe environment”. The site has launched a review of how it deals with violent content.

It’s hard to poke holes in Facebook’s official response – written by Justin Osofsky, its vice president of global operations – which at once acknowledges how difficult it would have been to do more, whilst simultaneously promising to do more anyway. In a timeline of events, Osofsky notes that the shooting video was not reported to Facebook until one hour and 45 minutes after it had been uploaded. A further 23 minutes after this, the suspect’s profile was disabled and the videos were no longer visible.

Despite this, the site has been condemned by many, with Reuters calling its response “bungled” and the two-hour response time prompting multiple headlines. Yet solutions are not as readily offered. Currently, the social network largely relies on its users to report offensive content, which is reviewed and removed by a team of humans – at present, artificial intelligence only generates around a third of reports that reach this team. The network is constantly working on implementing new algorithms and artificially intelligent solutions that can uphold its community standards, but at present there is simply no existing AI that can comb through Facebook’s one billion active users to immediately identify and remove a video of a murder.

The only solution, then, would be for Facebook to watch every second of every video – 100 million hours of which are watched every day on the site – before it goes live, a task daunting not only for its team, but for anyone concerned about global censorship. Of course Facebook should act as quickly as possible to remove harmful content (and of course Facebook shouldn’t call murder videos “content” in the first place) but does the site really deserve this much blame for the Cleveland killer?

To remove the blame from Facebook is not to deny that it is incredibly psychologically damaging to watch an auto-playing video of a murder. Nor should we lose sight of the fact that the act, as well as the name “Facebook killer” itself, could arguably inspire copycats. But we have to acknowledge the limits on what technology can do. Even if Facebook removed the video in three seconds, it is apparent that for thousands of users, the first impulse is to download and re-upload upsetting content rather than report it. This is evident in the fact that the victim’s grandson, Ryan, took to a different social network – Twitter – to ask people to stop sharing the video. It took nearly two hours for anyone to report the video to Facebook - it took seconds for people to download a copy for themselves and share it on.  

When we ignore these realities and beg Facebook to act, we embolden the moral crusade of surveillance. The UK government has a pattern of using tragedy to justify invasions into our privacy and security, most recently when home secretary Amber Rudd suggested that Whatsapp should remove its encryption after it emerged the Westminster attacker used the service. We cannot at once bemoan Facebook’s power in the world and simultaneously beg it to take total control. When you ask Facebook to review all of the content of all of its billions of users, you are asking for a God.

This is particularly undesirable in light of the good that shocking Facebook videos can do – however gruesome. Invaluable evidence is often provided in these clips, be they filmed by criminals themselves or their victims. When Philando Castile’s girlfriend Facebook live-streamed the aftermath of his shooting by a police officer during a traffic stop, it shed international light on police brutality in America and aided the charging of the officer in question. This clip would never have been seen if Facebook had total control of the videos uploaded to its site.  

We need to stop blaming Facebook for things it can’t yet change, when we should focus on things it can. In 2016, the site was criticised for: allowing racial discrimination via its targeted advertising; invading privacy with its facial-scanning; banning breast cancer-awareness videos; avoiding billions of dollars in tax; and tracking non-users activity across the web. Facebook should be under scrutiny for its repeated violations of its users’ privacy, not for hosting violent content – a criticism that will just give the site an excuse to violate people's privacy even further.

No one blames cars for the recent spate of vehicular terrorist attacks in Europe, and no one should blame Facebook for the Cleveland killer. Ultimately, we should accept that the social network is just a vehicle. The one to blame is the person driving.

If you have accidentally viewed upsetting and/or violent footage on social media that has affected you, call the Samaritans helpline on  116 123 or email jo@samaritans.org

Amelia Tait is a technology and digital culture writer at the New Statesman.

0800 7318496