3D printing supports sick sea lions in Southern California

In recent years, sea life along California’s southern coast has been in a state of crisis, with growing numbers of deceased or sick sea lions washing up on shore. The cause can be traced to toxic algal blooms and domoic acid in particular, which acts as a neurotoxin and can lead to seizures, brain damage, and death. In order to diagnose and treat sick sea lions that are beaching themselves, veterinary professionals are on site to collect blood from the animals. In an effort to improve this procedure and enable vets to work more efficiently, a team of researchers from the University of Nevada, Las Vegas (UNLV) as developed a synthetic sea lion pelvis using a combination of medical imaging and 3D printing technologies.

This 3D printed model functions as a training simulator: with a transparent structure and realistic bone and soft tissue textures, it enables veterinary professionals to practice sea lion blood collection with realistic feedback and clear visualization. Moreover, the phantom model enables repeated injections, facilitating lots of practice. The use of this model could ultimately improve real blood collection processes, which currently rely on manual touching to find the optimal blood collection spot and can therefore take significant time.

The 3D printed phantom models themselves are quite sophisticated and closely mimic the mechanical and anatomical properties of a sea lion’s pelvis. The team achieved this by using DICOM images generated from CT scans to create a realistic 3D model. From there, it leveraged both SLA and FDM 3D printing along with gel casting to create the tactile training device. The pelvis bone structure was 3D printed on a Formlabs Form 3 and subsequently dip-coated in a material that mimics tendon, ligament, and muscle tissues. According to the study published in Scientific Reports, the skin shell was also 3D printed using SLA, though instead of rigid resins used for the skeleton, they used elastic and flexible resins. The blubber layer was cast in a synthetic gelatin used to mimic tissue.

The result is a highly realistic simulator that enables vets or trainees to practice blood collection for sea lions with visual clarity and tactile responses. This can enable them to know where to place the needle and how deep to insert it before performing the procedure on a real animal. “Instead of using carcasses or cadavers, they can actually look at the lifelike organ,” said Kwang Kim, a professor of mechanical engineering and the study co-author. “You can imagine or read something, however, that can only take you so far. Having an authentic structure to train with is a unique opportunity with boundless potential. I think this is the tip of the iceberg.”

The study itself was initiated within the Active Materials and Smart Living Lab, a cutting-edge lab at UNLV run by Kim, who is himself recognized as a leading researcher in soft robotics. While the 3D printed sea lion pelvis could have a real-world impact helping vets diagnose, treat, and monitor the dire situation in California, the project is just the start for Kim and study lead author Daniel Fisher.

“The sky is the limit with this project,” said Fisher, UNLV engineering graduate researcher. “We’re trying to lay the groundwork for novel implants or procedures that can improve both human and animal lives, along with the environment. I believe that through careful simulation and anatomical modeling of our DICOM data, we’re able to 3D print any vein or arterial structure of a body. Through the use of micro-CT scans or MRIs, we’re able to get more detailed in our manufacturing, giving surgeons and veterinarians a way to practice any procedure.”

On his list of ambitions is developing artificial muscles that can be implanted. As he says: “My hope is to look at biocompatible materials that could restore a person’s hand function, or use an implanted artificial muscle. The more immediate impact is improving these veterinary procedures and benefiting the sea lions, but hopefully benefiting humans one day, too.”