Guest blog: New ways archaeologists ‘dig out’ answers

By: Victoria Nagy, MSc

After spending a field season conducting consultant archaeological field work in Ontario, I wanted to work in a research facility, an environment I enjoyed during my Masters studies. Therefore, I was excited to join the staff at Sustainable Archaeology: Western University. During my past undergraduate and graduate studies I had been exposed to digital archaeology and database development but I had never been able to directly apply those skills.

I was fascinated by the shear potential for research at Sustainable Archaeology since I was first introduced to the facility back in October 2015. As an archaeologist with a background in scientific applications, I was especially interested in its scope and equipment. Research facilities such as Sustainable Archaeology are extremely rare in Canadian archaeology, its existence and continuing innovation fill a scientific void in Ontario archaeology. Sustainable Archaeology: Western University and Sustainable Archaeology: McMaster University showcase how Ontario values archaeological research and will focus on scientific applications to further understand Ontario’s rich heritage.

Hilary Kiazyk, a part-time employee at SA: Western, using the Artec Spider to scan a mammoth tooth (a part of a collection from the Museum of Ontario Archaeology) (Feb. 29, 2016).

My first week at SA I familiarised myself with two of our 3D scanning technologies: the white light scanner and the mobile Artec Spider scanner (blue light scanner). I created a 3D model of a projectile point using the Artec Spider and tried my hand at using a white light scanner with a Historic smoking pipe. The Artec Spider blue light scanner proved to be my favourite piece of equipment in the imaging lab. The speed at which it captured images greatly shorted the imaging process. Also, the editing functions were easier to use and more comprehensive. I definitely enjoyed forming an opinion about these incredible pieces of equipment.

I was also able to print a previously rendered 3D model to better understand the 3D printing process. I learned how key texture editing is to the printing process. Since SA’s 3D printer is a powder printer that applies texture (colour in layman’s terms) during the printing process, editing the texture before printing to obtain the most lifelike texture (and then ensuring the texture seen on a computer monitor is adjusted to reflect the real texture) is essential to creating a lifelike replica. Through their work with 3D printing, SA is creating a new collection of archaeological mimics that can be used for display, study or function.

The applications of 3D scanning and printing are endless. Two replicas of the famed Ötzi were recently produced at Materialise in Leuven, Belgium as a dual effort by the DNA Learning Center and the South Tyrol Museum of Archaeology. The team who replicated Ötzi via 3D printing used a CT scanner to generate the 3D model of Ötzi, much like the Micro CT scanner SA owns and operates. The Micro CT scanner at SA is primarily used to understand the internal structures of artifacts. Internal structures can convey to archaeologists how artifacts were made, what materials were used, and reveal any unseen processes. Using a Micro CT scanner would have brought another dimension to my past research studying the newly introduced rehydroxylation (RHX) dating technique. I was only able to conduct Thermogravimetric Analysis (TGA), which analyses materials’ response to intense heat (Nagy 2015). Access to a Micro CT scanner would have provided me with a much more accurate examination of the internal construction of my samples. The fact that this equipment is available to Western students, and other researchers is so important for future research in Ontario and the wider academic community.

Staff of Materialise and Gary Staab (the expert paleoartist behind the Ötzi replicas - second from the left) (Cold Spring Harbour Laboratory 2016).

As my time at Sustainable Archaeology continues I am constantly amazed at this facility and the potential it represents for the archaeological community in Ontario. The non-destructive analysis conducted here is necessary for the archaeological research of the future. Sustainable Archaeology is providing the next generation of archaeologists with the tools they need to conduct high caliber research. Sustainable Archaeology has facilitated new processes for archaeologists to ‘dig out’ conclusions. I look forward to my time here and the research in the immediate future that results directly from Sustainable Archaeology’s efforts.


References

Cold Spring Harbour Laboratory (2016). The making of Otzi the Iceman. https://www.dnalc.org/programs/otzi.html?utm_source=ALL+CUSTOMERS&utm_campaign=9ea4241666-MED_Otzi&utm_medium=email&utm_term=0_7544445bcb-9ea4241666-63081529&goal=0_7544445bcb-9ea4241666-63081529.

Nagy, V. 2015. A methodological study of a simplified rehydroxylation dating procedure (Unpublished Master’s thesis). Durham University, Durham, UK.


Author biography

Victoria Nagy is a new addition to Sustainable Archaeology: Western University. Victoria graduated in 2015 with Distinction from Durham University with a Master of Science in Archaeological Science. In 2013, she graduated with Distinction from Wilfrid Laurier University with a Bachelor of Arts (Honours) in Near Eastern and Classical Archaeology. Victoria has conducted archaeological field work in Jordan, the United Kingdom, as well as northern and southern Ontario. She has joined Sustainable Archaeology as a Data Entry Assistant to aid existing staff with database development. This week is her fourth week with SA: Western.

3D Printing - testing size and colour

We have been running the 3D printer through its paces, working with scaling the printed objects, and with different processes and products for post-printing infiltration. 

Our test object was a small red projectile point. The point was first scanned in 2012 by the Sustainable Archaeology Animation Unit using the macro white light scanner.  

The untextured (left) and textured (right) scans of the point

In order to see how the printer was handling the detail captured in the original scans of the projectile point, we decided to print not only an original sized replica, but also one that was 2x larger, and one that was 3x larger.

Print in progress in the build bed

By scaling the model, we are able to better see with the naked eye the detail that was captured in the scan. Depending on the end user need, printing scaled versions of the scanned object may prove beneficial - for example, if there is detail not easily seen by the naked eye, or where we wish to isolate and print one segment of the object at a larger size in order to examine a specific feature of the original. For example, with our print, we are able to better see each flake scar on the point by examining the larger model, and could use the larger model to take measurements (converting to account for the size difference).

Scaled 3D prints (left to right): 3x larger; 2x larger; original size

Back side of the three printed points

In addition to testing scale, we were interested in testing how different infiltration products and methods affect the end product. We printed several copies of the point at its original size, and used the 3D Systems infiltrant Z-bond, as well as Paraloid B-72 resin, and the salt water infiltration we had previously used for our first print test.

Infiltrating the prints (left to right): Z-bond infiltrant; Paraloid B-72; salt water

Back of prints with different infiltrants (left to right): Z-bond; Paraloid B-72; salt water

As you can see from the images, the print infiltrated with the Z-bond demonstrates the most robust colour. The Paraloid resin offers a significant improvement over the salt water, and we plan to explore its use further, using different concentrations of the acrylic resin in acetone. As with scale, the end user need will help determine what infiltration product will be used with a print - for example if the user is interested in a print as a replication, or whether they simply wish to have a physical copy of the scanned object to handle and examine.

Comparison of the original artifact (left) with the Paraloid (center) and Z-bond (right) infiltrants

3D printer training and our first test print

On February 6th and 7th, we received training for our 3D Systems ProJet 660Pro printer. Training included not only how to set up and complete a print using the software, but also essential steps such as the cleaning  of the machine that is required after the conclusion of each print. 

After completing the necessary setup, calibration, and print head alignment, we performed our first test print, using a scan of a small bone comb that had been completed using Sustainable Archaeology's white light 3D digitizers. To test the process of positioning objects in the build envelope using the software, we printed three copies of the same object.

Printing in progress.

After a print is completed, the parts must be carefully excavated from the excess powder in the build envelope. The parts are quite delicate prior to any post-processing treatment, and can easily be broken during removal from the powder. Our objects were particularly delicate, as to maximize our training time, we did not allow for the usual one to two hours of drying time generally recommended between the conclusion of the printing process and the start of post-processing.

Excavating the prints

For our first test, we experimented with one of the available post-processing techniques, which is infiltration using a solution of Epsom salts and water. We plan to experiment further in the coming weeks to determine what scanning procedures produce the best files for printing, and to determine what post-processing techniques will produce the best colour replication. 

Front and back views of the completed print

The final print (right) and the original object

Notes from the SA: February - March 2013

The February - March 2013 edition of Notes from the SA, Sustainable Archaeology's newsletter.

Guest Blog #4: A Non-Destructive Technology for Palaeopathology: Differential Diagnosis of Cranial Lesions in Archaeological Human Populations

Jennifer Morgan is a PhD candidate in the Department of Anthropology at Western University.  Jennifer has been working with Sustainable Archaeology's microCT scanner to scan and analyze Maya and Egyptian archaeological cranial samples exhibiting cribra orbitalia and/or porotic hyperostosis in order to assess whether the microCT is a more effective tool than destructive thin section techniques to study the etiology, activity, and healing of the lesions. 

This blog features Jennifer's contribution to the upcoming edition of the Sustainable Archaeology newsletter, Notes from the SA, which will be published on February 7th.

A Non-Destructive Technology for Palaeopathology: Differential Diagnosis of Cranial Lesions in Archaeological Human Populations

Jennifer Morgan, PhD Candidate, Western University 

Palaeopathology is defined as the scientific study of disease processes from archaeological human remains. The pattern of disease that affects a population is the expression of the biological and cultural stressors to which they were exposed. It is influenced by the environment, sex, social status, diet, occupation, and even cultural belief systems. These factors help researchers to interpret and explain the patterns of disease observable on human skeletal remains. Recent microscopic analyses of bone have revealed that porotic lesions of the skull, referred to as cribra orbitalia and porotic hyperostosis, can be caused by more than one health related condition. Originally associated with anaemia, other conditions including vitamin deficiencies and localized infections have also been implicated as possible causes of these lesions. Therefore, it is critical to establish methods that can accurately assess health conditions from skeletal remains. Inaccurate diagnoses can have significant implications for our current understandings of how disease and other health related conditions may have evolved over time, across geographic space, and how they may have affected human populations in the past.

The purpose of my current doctoral research is to examine an innovative non-destructive method for improving the accuracy of disease diagnosis in archaeological skeletal samples.  The principal objective of this study is to determine whether micro-computed tomography (μCT) and advanced methods of digital image analysis can be used in palaeopathology to visualize small scale bone changes which are typical of certain health conditions. The goals of this research are two-fold.  First, I wish to assess the capability of μCT and digital image analysis as sufficient alternatives to destructive thin section techniques which are traditionally used for microscopic skeletal analysis in bioarchaeological research. Second, I wish to evaluate the ability of µCT for more reliable differentiation between the various pathological conditions that contribute to the presence skeletal lesions in archaeological human remains.

Why is this significant?  In order to establish a reliable diagnosis it is often necessary to analyze the microscopic structures of diseased bone. Microscopy is essential in palaeopathology since although several disease processes can lead to similar bone surface changes, microscopic analyses demonstrate that there are patterns of microscopic changes which are unique to specific diseases. The classic way to examine bone microscopically is through the use of histological thin sections of bone, which require significant preparation and destruction of the sample. The method proposed for my doctoral research, using μCT, requires little to no sample preparation and is a method which has the potential for high resolution bone analysis, while eliminating the need for destructive sampling of valuable archaeological remains. 

For this research project, skeletal samples have been drawn from an Egyptian and several Maya collections housed at Western University in London, Ontario.  A large number of individuals with observable porotic cranial lesions have been μCT scanned in the Ancient Images Laboratory.  The resulting images are currently being qualitatively and quantitatively analyzed using the digital image analysis software VGStudio Max 2.2. These analyses of bone structural changes will determine whether the characteristic microscopic patterns indicative of anaemia, vitamin deficiencies, and infectious processes described in the literature can be differentiated using μCT. It is anticipated that the results of this research project will make a significant contribution to palaeopathology by providing non-destructive, high resolution digital techniques for the diagnosis of disease from archaeological skeletal samples as well as vastly improving our epidemiological understandings of health and disease in archaeological populations.

MicroCT Rotating Target and a Holiday Fruit Cake

In the Sustainable Archaeology Ancient Images Lab, we've been performing proof of concept tests using the rotating target on the microCT. The rotating target enables the user to "up" the flux (amount of power) that can be delivered to the target, without degrading the spot size - essentially allowing for faster scanning without compromising the excellent resolution of the machine. This give us the ability to greatly increase the amount of power we can use in a scan, allowing us to scan very dense objects, including meteorites, or, holiday fruit cake!

Special thank you to Hope Miles for providing the delicious fruit cake!

3D Printer Demos

 

One of these items is the real thing - the other has been printed on a ZPrinter (450 model) from Zcorp. Can you tell which is which? The bottle, complete with threads (and fitted cap) and colour label is the printed object.

This week we attended vendor demonstrations by Cimetrix Solutions and Agile Manufacturing for 3D printers as we prepare to purchase this equipment for SA Western. The equipment will be used to print a variety of archaeological materials in 3D, including artifacts scanned using SA's 3D digitizers. 3D printers are widely used in the worlds of manufacturing and prototyping, for everything from machine components to jewellery, to chocolate - even GIS data can be used to print 3D models of landscapes. 

Digital Artifact Ecosystems: The "Internet of Things" in Archaeology

The video below features the paper "Digital Artifact Ecosystems: The "Internet of Things" in Archaeology" (Namir Ahmed, Michael Carter, Neal Ferris) presented by Western University MA student Namir Ahmed at the Digital Engagement in Archaeology conference this past week. The conference ran November 8th and 9th at the UCL Institute of Archaeology in London, England.

Other videos from the conference can be viewed at Doug's Archaeology blog. Thanks to Doug for posting these! To see conversations and chatter from the conference, check out the hashtag #digipubarch on Twitter.

Yes the Cat: A Study of Mummification

The "Yes the Cat" project is an interdisciplinary investigation led by Dr. Andrew Nelson of the Department of Anthropology at Western University. The project is an ongoing study of the effects of mummification on different tissues of the body as demonstrated by the individual of interest - a domestic house cat named Yes.

Yes was mummified at the request of his owner, after dying of natural causes eight years ago. Since the time of the mummification, he has been studied using MR and clinical CT imaging in order to see beneath the exterior wrappings, to examine how the remains have changed over time.

Most recently, Yes the Cat was scanned using Sustainable Archaeology's microCT scanner. The microCT provides an additional means to non-destructively examine Yes the Cat's "afterlife", without removing any of the wrappings or disturbing the remains below. In the video below, Yes's skeleton was isolated from the layers of wrappings, which are digitally removed, allowing for the examination of the skeletal remains.

                                     

 

By isolating different densities, the researchers were also able to examine the condition of remaining internal organs, such as the heart, seen in red in the image below.

This cross-section, produced using the SA microCT's software, provides a more complete picture of Yes - through the wrappings down to the skeleton, also revealing what remains of the brain, heart and tongue.

Through digital imaging, Yes the Cat will continue to be a source of information about the effects of mummification for years to come, contributing broadly to our understanding of mummification and how mummified remains change over time. These findings can be applied to other cases of mummification, including both humans and other animals.

The Yes the Cat project will be presented at the upcoming Annual Meeting of the Canadian Association for Physical Anthropology at the University of Victoria in Victoria, B.C., on November 13th.

What Can We Learn About Ceramics?

Examining digital scans of archaeological artifacts can tell us how an object was made, what materials it was constructed from, how it was used, how it was broken or mended, or how it has changed over time. Digital scans can aid in identification of materials, or in plans for conservation. Through past blog posts and videos, we've demonstrated the capabilities of Sustainable Archaeology's MicroCT scanner for digital analysis and non-destructive studies of a range of archaeological materials. We've demonstrated the potential for examining pathologies (evidence of past injury or disease) in bone, and for revealing previously unknown aspects of artifacts - from what lies below the rust of a metal object, to what the interior of a historic pipe looks like. This week, we turn to ceramic material, and to what a digital scan of a ceramic object can reveal.

Happy Anniversary to Western SA!

Today marks the first year anniversary of Western's SA occupancy permit. Over the course of this past year, we've seen the finishing touches done to the building, had our safety checks and we've purchased our computers, 3D scanners, MicroCT, digital x-ray and an electric work assist vehicle.We've hosted a three month 3D/animation internship and a three week thin-sectioning workshop. Our geophysical equipment has been used at a number of archaeological sites, including at Techumseh Park in Chatham, Ontario (last September), and at Fort Erie this summer. We've welcomed tours of representatives from the Canadian Foundation for Innovation, the First Nation's Financial Management Board, the Smithsonian Institution, the Art Gallery of Ontario, Mitacs, local Rotary clubs, as well as hosts of individuals from across Ontario and around the world who are interested in Sustainable Archaeology and the philosophy we espouse. We've also begun to establish communication with a variety of other archaeological facilities and institutions, such as the Center for Digital Archaeology at the University of California, Berkley.

Over the course of the next year, we look forward to growing and settling into our space. We have more equipment to purchase (including a 3D prototyper and Virtual Imaging station), more courses and workshops to host, and we're looking forward to having some substantive information to share about our project at a number of local and international conferences. Watch for representatives from SA Western and SA McMaster at the Ontario Archaeological Society meeting in Windsor and the Canadian Association for Physical Anthropology conference in Victoria, BC in November 2012, as well as the Society for American Archaeology conference in Honolulu, Hawaii in April 2013! 

Mystery Object Revealed!

At first glance, this artifact did not appear to be anything particularly special - a chunk of rust and corrosion found in a box with other rusted metal pieces from a historic site collection held by the Museum of Ontario Archaeology. Our imaging lab tech Zoe was in the midst of performing various proof of concept tests on the MicroCT, and we decided that this would be an interesting piece to scan. We had no idea what we would find below the rust - historic sites often yield a wide array of metal artifacts, and our mystery piece could be one of any number of things. Or was their nothing to discover at all - could this simply be a piece of rust that had broken off of another object?

As seen in the video, using the MicroCT, Zoe was able to isolate and strip away the less-dense layers of rust and corrosion, revealing two small thin metal objects below. Mystery artifact appears to be (drumroll please) - a nail! Or, at least one nail, and possibly part of another. What do you think the mystery object could be?

Sustainable Archaeology on CTV London

Sustainable Archaeology and the SAAU were featured on CTV London on Friday, August 10th. Check out the video below!

Ever Seen a Snake Shed its Skin?

 This week we have another video to share from the Sustainable Archaeology MicroCT scanner - this time featuring a preserved Fox Snake that through screen shots and a video digitally "sheds" its skin to expose the skeleton below. Using the MicroCT's reconstruction software, our imaging lab tech Zoe was able to isolate and expose the more-dense skeleton by digitally removing the less-dense flesh and skin of the snake - allowing us to see inside the snake digitally and non-destructively. 

  

From left to right, see the snake's skin digitally removed to expose the preserved skeleton below.

Working Through the Scanning and Modeling Process

We've posted a new video on our Youtube channel, Archaeology3D, featuring a rotational view of a large rim portion of a ceramic vessel from the Museum of Ontario Archaeology's gallery. The video and digitization was produced by SAAU interns Kelsey Baxter, Alan Bartholomew, and James Meager. The rim was scanned using one of Sustainable Archaeology's 3D3 digitizers - the structured light scanner, which has been set up for the scanning of larger artifacts (in contrast to the macro structured light digitizer, which is used to scan very small artifacts).

A 16 megapixel Canon Rebel T3i was used to capture the artifact's original colour and texture. Flex software was used to align and merge the digital scans and to export into an OBJ. Holes in the geometry were filled using the Rapidform software, and the high resolution texture was applied from the Canon camera to the high resolution 3D model using Z-Brush. Everything was then pulled together into Maya and rendered using Mental Ray.

Below are two screen shots from the digitization process. These images demonstrate the contrast between the textured (top) and untextured (bottom) 3D models. The ability to add texture to the 3D model allows for the creation of truly life-like digital versions of the original artifact.

Scanning Videos on Youtube

We've posted a couple of quick video clips on the Sustainable Archaeology Youtube channel, Archaeology3D. This video of a deer bone bead with the texture added to the scan, demonstrates the ability to zoom and rotate an object on-screen. The second video, which can be viewed on the Youtube channel, gives an idea of the the set up for scanning with the 3D3 digitizers upstairs in the mezzanine area.

Keep an eye on the channel for more videos as the SAAU continues scanning artifacts for their Lawson site project.

Gallery Scanning

The SAAU has set up the Vivid 9i in the Museum of Ontario Archaeology's main gallery, scanning a range of artifacts, including pottery and stone tools, that will be used in the CG animation of the Lawson site.  Trays of smaller artifacts have also been making their way from the gallery to the SAAU workspace in the mezzanine to be scanned by SA's 3D3 scanners, including the 3D3 macro structured light digitizer.

                                         

One-of-a-Kind Digital Imaging

As we mentioned in a previous post, Sustainable Archaeology has been hosting students of Loyalist College as members of the Sustainable Archaeology Animation Unit (SAAU) over the summer. They've been steadily working over the last several weeks, working on a CG recreation of the Lawson Site for the Museum of Ontario Archaeology (next door), scanning a wide range of different artifact types, and working out scanning protocol that will be used by Sustainable Archaeology. 

The images of these projectile points were produced on Sustainable Archaeology's 3D3 macro structured light digitizer. This digitizer was custom made specifically for the Sustainable Archaeology facility by 3D3 Solutions, and is the only machine of this type that they have ever produced  - in fact we believe this machine to be the only one of its kind in Canada! The machine includes two colour capture cameras, and is able to scan objects that are between approximately 2-5cm, while still capturing an intense level of detail. 

To demonstrate the capabilities of this digitizer: the image on the left shows an untextured scan of a small projectile point (approximately 5cm) using the macro digitizer. The image on the right is the same point, but in this case, the original colouring and texture of the stone has been added to the untextured scan. When viewing this object as a scalable model (rather than a screen shot, as seen here), with the ability to rotate the point in all directions, you are able to view in intense detail the way in which the point was manufactured.

       

What's in Your Basket?

  Our Imaging Lab Tech Zoe has been continuing with proof-of-concept testing on the MicroCT scanner, generating some really amazing images. Like a CT scan at a hospital, which allows doctors to take digital "slices" to see inside a patient's body, our Micro-CT allows us to see inside artifacts. This screen shot shows a basket, into which Zoe placed a ceramic ball (left), a dog canine (in front of the ball) and an acorn (right). After scanning, she was able to "slice" through the image digitally to look at what was contained inside the basket, and in this image, has begun to slice through the acorn as well. Imagine the possibilities for non-invasive studies of objects with this ability to look within!

This screen shot shows a historic pipe made of what we believe might be meerschaum, or possibly "horn" (a substance made of molded cow hoof). Slicing through this image allowed us to see how the interior of the pipe was formed, providing clues to how it may have been made.

3D3 Scanner

It's been another busy week for Sustainable Archaeology, and for the interns of the Sustainable Archaeology Animation Unit (SAAU). They've been unpacking and setting up  Sustainable Archaeology's newest 3D scanners from 3D3 Solutions upstairs in the mezzanine workstation. Here, two of the interns work at calibrating the new scanner.