Tiny Carved Human Sculptures Might Have Been Medical Teaching Tools

CHICAGO — Micro-CT scans offered new insights into the purpose of small, antique “manikins,” or intricately carved human anatomical sculptures with removable organs, a Duke University researcher reported here.

The study focused on Duke’s collection of manikins, which range in length from 4 to 8 inches, thought to have been carved in the late 17th century in Northern Germany.

At one time, the highly detailed figurines were thought to have been designed for anatomical and medical studies, but that now seems unlikely, said Fides Schwartz, MD, in a presentation at the Radiological Society of North America annual meeting.

“We can see that these manikins — mostly women, and many of whom are pregnant — were made [mainly] of ivory, which means they would have been prohibitively expensive to have been used as medical teaching tools, as once believed,” Schwartz said.

“I think that would indicate they were made for wealthy patrons, or possibly as toys for them or their children,” he suggested.

Duke owns the world’s largest manikin collection — 22 out of 180 known manikins worldwide — that Schwartz and colleagues studied with x-rays and micro-CT scans. They also had the manikins and their internal organs 3D-printed in plastic to avoid damaging such fragile items.

“None of the manikins are signed so the name of the sculptor or sculptors has been lost,” Schwartz told MedPage Today. Most of the manikins in the Duke collection were purchased in the 1930s and 1940s by Josiah Trent, MD, a thoracic surgeon, and his wife Mary Duke Biddle Trent, prior to the 1989 ivory trade ban.

The reclining manikins come with their own “beds” with pillows and linens made of wood. A manikin’s chest and abdomen can be removed to reveal a heart, lungs, kidneys, uterus, and even a fetus in one case. The internal organs can also be removed. All the dolls appear to have different facial features and hair styles, Schwartz noted.

She also pointed out that the manikins’ “lungs are the same size [as each other], and I believe that in that time frame, doctors knew that the left and right lungs were different sizes so that again leads us away from a medical purpose for the manikins.”

Using micro-CT, which has much higher resolution than standard CT, the researchers were able to analyze the microstructure of the material used, Schwartz explained. “Specifically, it allows us to distinguish between ‘true’ ivory obtained from elephants or mammoths and ‘imitation’ ivory, such as deer antler or whale bone,” she said in a press statement.

The researchers also found metallic components in four of the manikins, and fibers in two. Twelve manikins contained hinging mechanisms or internal repairs with ivory pins, and one manikin contained a long detachable pin disguised as a hairpiece. Identifying non-ivory components in the manikins may provide more accessibility to carbon dating, allowing the researchers to more accurately estimate the age of some of the manikins without causing damage.

Frank Rybicki, MD, of the University of Cincinnati, called the research “one of the more fascinating studies from this year’s RSNA. It really shows us how we can use medical tools to expand our knowledge of things not necessarily medical.”

Rybicki, who was not involved in the study, suggested that 3D printing of the manikins could offer more insights into the manikins’ purpose, as “it is all conjecture as to what their purpose was. It could have been for studying medicine; it might have been part of rituals; it could have been toys for royals.”

Schwartz and colleagues said they hope to acquire 3D scans to create digital renderings and enable subsequent 3D printed models.

“This is potentially valuable to scientific, historic, and artistic communities, as it would allow display and further study of these objects while protecting the fragile originals,” she said. “Digitizing and 3D printing them will give visitors more access and opportunity to interact with the manikins and may also allow investigators to learn more about their history.”