3D printed surgical models are quickly becoming commonplace in hospitals all around the world, providing surgeons with the opportunity to physically interact with their target areas and adequately prepare for the coming procedures. While these 3D prints have already shown to increase surgical success rates, models that feature realistic textures could take these preparation opportunities to the next level – while simultaneously forming fantastic educational tools for tomorrow’s generation of surgeons. Dr. Maki Sugimoto has therefore developed what he calls Bio-Texture Modeling, which creates 3D printable organs that are both anatomically correct and realistic in texture, mass, and other physical qualities, using water-retaining plastics.
This fantastic design platform has quite a long history, and actually grew out of Sugimoto’s work with developing 3D displays of x-rays. “X-rays of a patient are as real as it gets,” Sugimoto explained. “They are taken directly from the patient using medically approved equipment and techniques, and they are a reliable source of data for patient diagnosis. However, untrained patients do not know how to interpret such images, and often I had to resort to sketching their organs on paper while showing them the x-rays to close this gap in understanding. As you may expect, this was not a very reassuring or convincing approach for the patients.”
Fortunately, Sugimoto stumbled across OsiriX, an open-source application that allows x-ray data to be viewed in 3D – perfect for viewing x-ray images in 3D and a great tool to have nearby in the OR. To bring those displays a bit closer to the operating table, Sugimoto eventually started projection mapping directly onto the patient’s body – allowing for the visualization of the position of organs, blood vessels and more before cutting someone open. “While the technology was incredibly simple, its impact was immeasurable,” Sugimoto recalls. “At first, some of my colleagues couldn’t believe such tools were being used in the operating room. They thought I was playing some kind of game!”
While already a huge boon during surgery this was only the beginning for Sugimoto, who started incorporating OsiriX into his own software development, creating VR and 3D printing possibilities – which he saw as having tremendous educational potential as well. “Taking the example of a cancerous tumor, if you wanted to know where to make the incision and how much to cut out, you would need information on both the tumor’s shape and position,” Sugimoto says. “However, on top of that, a surgeon will want to know how that shape will feel in their hands, making a 3D model necessary. It is key for the surgeon to be able to handle the model and interact with it.”
He eventually developed a new organ replicating method called Bio-Texture Modeling. While existing organ models can be identical to the real thing in shape already, this method actually realizes the elusive lifelike textures as well. Although virtually all 3D prints are rigid in texture, Sugimoto even added moisture content by 3D printing in a water-retaining resin. The result are anatomically correct structures which look, feel and behave just like those kidneys or tumors in the human body.
As Sugimoto explained, that inclusion of liquid materials is absolutely crucial for the final results, and is achieved by calculating the percentage of water or other liquids in the target tissue. “Why does the water content make the organs seem so real? Just as carbon is the basis of all living things, water is also an essential component,” he explains. “Fluid bodies are evocative of life: If we are cut, we bleed; squeeze the wound and other fluids ooze out, as well. Models that can replicate these phenomena are incredibly lifelike.”
In fact, Sugimoto was one of the first patients to discover the surgical potential of this approach himself – after sustaining a life-threatening spinal injury while skiing. “The surgeon in charge was able to gain tactile feedback by touching both the affected area on me and the model and, as a result, was able to perform the surgery more safely and accurately,” Sugimoto recalls. “He was able to close his eyes, focusing completely on the tactile sensations to gain the feedback necessary for the procedure.”
The same principle could be applied to a very wide range of surgeries and provide surgeons with the opportunity to practice techniques in advance – also greatly increasing their confidence. As you can see in the clip below, the interiors of these prints are stunningly detailed and lifelike. Sugimoto is therefore currently promoting his open source solution, which has also received backing from Apple and Autodesk. “But access to my work should not be limited to a few; I want to make it more accessible to the people of the world and improve everyone’s lives. While many doctors want to excel at the highest levels of their profession, I want to lower barriers and bring my work to the general public,” he says.