Using a combination of 3D printing and soft materials such as silicone, polyester polyurethanes and polymer waxes to create lifelike organs.
Traditionally, cadavers have been one of the main tools for surgical training for medical students, surgeons and trainees, emergency medical professionals, researchers and military medical personnel.
The history of cadaver use in science and medicine
The history of cadaver use in medical training dates back to the first half of third century BC in Greece. Ancient Greek physicians Herophilus of Chalcedon and Erasistratus of Ceos were likely the first to use the dissection and vivisection of cadavers for anatomical learning.
By the 4th century CE, much of cadaver use disappeared owing to religious and social taboos. It did not reappear until the 14th century in Bologna, Italy, and from this point on, became increasingly common. However, the use of cadavers for surgical training and preparation is flawed and has recently waned in popularity.
The process of cadaver acquisition is complex and preservation is expensive. While anatomically accurate, cadavers lack the same physiological functioning such as blood flow and dynamic responses. Embalming can help to prevent the organs from descending with gravity. However, the use of hazardous chemicals such as formaldehyde not only poses a risk to users but also contributes to tissue discolouration and stiffness.
An alternative to cadavers
Alternatives to cadaver use have recently been gaining traction. Dr Richard Arm, senior research fellow, Nottingham School of Art and Design, NTU has introduced an anatomically accurate solution that offers many advantages over cadavers. Arm uses a combination of 3D printing and soft materials such as silicone, polyester polyurethanes and polymer waxes to create lifelike organs.
His interest in art and design began with the Renaissance movement and multi-disciplinary creatives such as Di Vinci and Michelangelo, who were not just artists, but designers, inventors, builders, architects and engineers as well.
“Art underpins all these disciplines, and it’s no different for me,” says Arm. “A broad working knowledge of science, medicine, anatomy and material science are all essential to my work. Understanding the human body, how it works and why, can lead the open-minded artist down a plethora of avenues for discovery and inspiration.”
While often overlooked by decision-makers in education, the arts contribute to the holistic perspective and lateral decision-making necessary to approach the replication of just one human organ, let alone the complexity of the human body.
“Human skin is a great example. Resilient, repairable, and compliant, human skin has some unique characteristics that are controlled by its makeup,” says Arm. “Layers, fibre-filled gel membranes and elastic embedded structures are all replicated in the work I do, inspired by nature’s own design.”
How it works
First, a 3D print of the tissue is created based on a patient’s CT scan. This ensures that the blueprints of the anatomical structures are accurate to the training required. This alone could eliminate the difficulties surgeons experience when training for paediatric patients, for example.
Following the creation of the 3D replica, Arm uses soft materials to recreate the elasticity, flexibility
and unique characteristics of specific organs.
“We use a variety of materials to simulate living soft tissues,” says Arm. “For example, for complex vasculature that needs interlinked vessels with specific wall thicknesses that would be impossible to cast, we use a laser sintering technique to fuse soft rubber particles together using 3D guided geometry.”
Every aspect of the body is considered, including the way the blood sinks into the body following an incision, rather than puckering upward, as is often seen in media.
“It’s important that any materials we use are compatible with one another, such as PDMS (silicone gels) polymer waxes and thermoplastic polyurethanes,” says Arm, who rarely uses materials straight off the shelf.
“Liquid and solid additives are used in combinations that are essential to change and control the fundamental mechanical characteristics in most materials, to emulate the native biological tissues properly,” he says.
The advantages
One advantage that Arm’s method has over cadavers is its availability. For a host of cultural, legal and religious reasons, the availability of cadavers around the world is inconsistent and controversial. In the UK, for example, cadavers are only available as a main teaching method in about 60% of British medical schools.
Arm’s organs are also reusable, portable and independent from any power source. While cadavers must be properly preserved and respectfully disposed of within a certain time frame, these artificial organs can be left out and even transported without being damaged.
Since Arm’s organs are created from scratch with the purpose of mimicking life-like physiological responses, they bypass the complications and costs that arise from preserving cadavers through embalming, which alters the appearance and composition of
soft tissue.
The customisable nature of Arm’s approach makes it suitable for a wide range of situations. He has previously assisted in the training of heart transplant surgeons and first responders treating serious chest trauma that occurs from gun shots, stabbings, shrapnel penetration and road traffic accidents.
What’s the latest?
While Arm has several projects underway and still under wraps, he has already begun manufacturing his own manikins and organs at NTU with the help of his research assistant Andrea.
“The reason for us manufacturing our own models rather than licencing our technology is to help drive down inflated prices of surgical models because we want everyone to be able to afford them, not just the privileged few,” says Arm. “We also want to improve and control the quality of the currently available models by designing and building everything in-house.”
Arm’s manikins and organs are available for purchase through NTU’s catalogue of products.
For more information visit: www.ntu.ac.uk
