Unless you’re stuck on the I-805 during rush hour and happen to glance eastward, you might not notice the place. But any area resident who has had a sick child knows the way there quite well. According to its website, Rady Children’s Hospital-San Diego is the largest children’s hospital on the West Coast, the only facility in the area dedicated exclusively to pediatric health care, and the region’s only designated pediatric trauma center.
It’s also where Justin Ryan, PhD spends his days trying to improve the already exemplary level of care that more than 281,000 children have received since the hospital’s founding in 1954.
Ryan is a research scientist and director of the Helen and Will Webster Foundation 3D Innovations (3DI) Lab. Don’t thank him for introducing the hospital to additive manufacturing (AM), though. Those accolades go to pediatric cardiologist Dr. Sanjeet Hegde and cardiothoracic surgeon Dr. John J. Lamberti, who laid the groundwork for 3DI by using cardiac scans to generate digital datasets of young patient’s hearts, then working with external service providers to 3D print physical models. Simultaneous to these endeavors, the orthopedic program was also using an extrusion-style desktop 3D printer for research and surgical planning.
Ryan entered the picture soon after, when Rady Children’s formalized its 3D-printing pursuits in the spring of 2018 and put him in charge of the newly formed department. He was also there when 3DI received “a significant grant” from the Helen and Will Webster Foundation one year later, allowing him to hire Parham Gholami, a software engineer with extensive experience in video game development.
What do video games have to do with the printing of patient-specific models that allow physicians to practice upcoming procedures, and better visualize the internal workings of their small patients? Quite a bit, according to Ryan.
“I wanted to make it easier for people with limited computer experience to visualize and interact with the complex three-dimensional datasets that any radiology lab produces,” said Ryan. “Who better to accomplish that than someone who develops virtual reality software?”
This story isn’t about Gholami, however, despite his contributions to 3DI’s work. It’s about saving children’s lives, something the lab assists with in numerous ways. For instance, the team might print a replica of a patient’s heart or lungs for surgical planning. That same model could also be used to explain the upcoming procedure to family members, train medical students, and evaluate novel instruments or techniques, all of which enhances the medical community’s capabilities and improves patient outcome.
Brains, bones, blood vessels—all these and more can be imaged via computed tomography (CT) scanning or magnetic resonance imaging (MRI). The resulting “slices” are then reconstructed into a digital model, and the results are sent to one of half a dozen 3D printers at the 3DI Lab. These include an HP Jet Fusion 580 Color 3D printer, a J750 Digital Anatomy printer (also color) and an F370 FDM machine, both from Stratasys, and a few vat photopolymerization (SL) printers from FormLabs and 3D Systems.
Whatever AM technology was used, such 3D-printed organs and musculoskeletal reproductions do much more than bring physicians and patients up to speed—they also help identify potential fit and function roadblocks with surgical devices, which are often too large for young patients or have not been optimized for their faster blood flow and relatively soft bones. And from a larger perspective, 3DI Lab’s work benefits the medical industry as a whole by bringing together huge amounts of patient data that can be used to research diseases, genetic defects, and other life-threatening abnormalities, and then develop the most effective treatment options.
“It’s a challenging aspect of the business that there are a lot more sick adults than sick kids, so that means medical devices and therapies are often focused on this larger [adult] market segment,” Ryan said. “So one of our goals is to make it easier for medical device companies to get into the pediatric space and develop critical solutions for what is clearly a much smaller customer base. It’s a challenging business model, but if we can help them leapfrog the status quo by utilizing 3D datasets and 3D-printed models, we will ultimately bring more medical devices to the pediatric domain.”
According to Ryan, 3D printing is only part of what he and his team do, and in some ways, it’s not even their primary focus. “We take a holistic approach to this technology, and that includes a strong emphasis on applications that leverage the three-dimensional datasets created through CT and MRI imaging. This was a big part of why I hired Parham.”
As noted earlier, Gholami has a background in video game development. He is therefore well equipped to develop an intuitive user interface that allows medical personnel to quickly review and analyze these 3D datasets. Provided the virtual models are sufficiently robust and accurate, this might eliminate the need to 3D print a physical replica, saving the hospital money and getting important information into practitioners’ hands more quickly.
The process of generating these models is called segmentation and reconstruction. It’s normally performed by a highly trained technologist or radiologist and saved in a Picture Archiving and Communication System (PACS) database.
PACS databases are optimized for the radiologists and rarely consider the end user being a surgeon or interventionalist. Gholami—under Ryan’s direction—developed a 3D viewer that provides the radiologic results to the surgeon in an intuitive manner. The result is a streamlined surgical planning experience. Because Gholami “removed around 50 buttons” compared to legacy viewing tools, the software is easy enough for anyone to navigate.
Gholami also developed a tool that helps any hospital bring 3D datasets into their PACS environment. The no-cost software Media2DICOM takes an electronic folder filled with image or 3D files and compiles them into Digital Imaging and Communications in Medicine (DICOM) format, the industry standard. Media2DICOM also supports the addition of metadata that, according to Ryan, is not only a huge time saver but eliminates the possibility of errors.
“Most hospitals generating 3D datasets rely on engineers to assign file names and store images in the proper folders. But this doesn’t provide the level of control or detail that many practitioners would like to see, so we allow users to assign metadata to their 3D objects, avoiding the remote possibility that a 3D heart image belonging to patient Smith could accidentally get assigned to patient James.”
Ryan notes that the response has been quite positive and “overall numbers have skyrocketed” on these digital reconstructions, as well as those produced via 3D printing. His and Gholami’s next step is to equip their software with virtual reality (VR) or augmented reality (AR) capabilities. “Anything we can do to provide a greater sense of depth and perception will be a big step forward, and AR/VR shows great promise in this respect,” he said.
Another potential big step forward is one that’s out of Ryan’s control: greater build speed. “It’s unlikely that we’ll ever be able to print anything fast enough for a patient who has experienced significant trauma because they’re typically moved to surgery quickly, but we would love the ability to print models for surgeries consistently later in the day. That’s very challenging right now, as we usually need a full business day to turn something around.”
He’d also like to see the industry develop more “human-like” materials. Although companies such as Stratasys have done a good job at giving 3D-printed organ models realistic colors, surgeons want these replicas to feel like muscle and tissue, not polymer, when they slice into them.
Another nice-to-have feature would be greater sterilizability. Ryan noted that HP Inc. and Formlabs offer materials that are suitable for the operating room, but such materials are not as widely available across other technologies as he’d like. “Medical teams would prefer to have the 3D-printed models they practiced on available as a reference during the actual surgery,” he added. “We can’t always give them that with our current printers and materials.”
Ironically, Ryan never intended to go into the medical field, although he’s had an interest in 3D printing since his early days volunteering at a research lab while attending Arizona State University. Back then, he was pursuing a career in art animation, or as he likes to put it, “Pixar special effects-type stuff.”
That eventually led him to biomedical engineering, first as a research scientist and director of the Cardiac 3D Print Lab (established 2012) for Phoenix Children’s Hospital, and now at Rady Children’s. Through it all, he’s enjoyed leveraging AM’s capabilities in this area and, most especially, making a positive impact on children’s lives.
“Like I said, I’d planned to go into computer graphics and probably get a job in the entertainment industry after college,” he said. “But once I got involved with 3D printing and the development of heart models for young people, everything just kind of clicked. It’s a very rewarding career.”
