Third-year student Megan Lin and Dr. Jonathan Wood
How can Penn Vet students operate on a real dog’s spine without ever touching a real dog? The answer isn’t a riddle, it’s augmented reality.
This spring, Penn Vet is launching an augmented reality interface for an exacting spinal cord surgery. The program is the latest addition to the School’s growing portfolio of digital and advanced technology for teaching and clinical care.
A brainchild of Penn Vet staff neurologist Dr. Jonathan Wood, the idea, like so many innovations are, was born from necessity.
It all began a few years ago with a difficult canine case.
Entering Three Dimensions
During his residency at Penn Vet, Wood and Dr. Evelyn Galban, Clinical Assistant Professor of Neurology and Neurosurgery, were treating an eight-month-old dog who had a large tumor on her skull. “Surgery was possible, but because of the tumor’s placement there was little margin for error,” said Wood. “I wanted to understand the tumor’s position and how to proceed before actually operating.”
The dog’s two dimensional CT scans only gave a limited view of the problem. It wasn’t enough to provide the multidimensional perspective Wood needed.
“Our team got to talking about how to train students for rare cases that a surgeon might only perform once or twice in a lifetime—it’s a puzzle every teacher grapples with at some point,” explained Wood. “In this dog’s case, 3D printing was the perfect solution.”
Wood found a 3D printer at PennDesign’s Fabrication Lab. The Lab printed an exact model of the dog’s skull, enabling Wood to see the case from all sides and plan a course of action.
Although the dog’s owner ultimately decided against surgery, Wood and Galban had opened a new dimension for Penn Vet faculty and students. They have since used 3D models to prepare for life-prolonging surgeries for two canine patients; created 3D replications for other species, including a rabbit’s skull and the rib cage of a cat; and printed a prosthetic leg for a parrot.
With this growing library of 3D models, Wood wanted to push other boundaries. “What if we could take an image from a patient and turn it into more than a model but a reality,” he questioned.
From 3D to Reality
Wood became interested in augmented reality, which is an interplay between real objects and animated objects—the most widely-known example is Pokémon GO.
An expert in the technology—Dr. Stephen Lane, Director of the University’s Computer Graphics and Game Technology Masters Program—was right across campus at Penn’s School of Engineering and Applied Science.
“Steve has years of experience in gaming and developing simulations for real world application like military combat training,” said Wood. “That’s what I wanted: Someone who could help us feel like we’re right in the moment—right in the surgery—doing real things even before we have a patient. I emailed him and he got right back to me.”
This was more than a year ago. In the time since, Lane and Wood have developed an augmented reality program that animates a canine spinal cord for a process called atlantoaxial stabilization.
The hologram overlays the spinal cord model, as seen through the HoloLens.
The procedure helps correct atlantoaxial instability, a condition that occurs when the first (atlas) and second (axis) vertebrae of the spine don’t articulate well together. Common in small breed dogs, such as Chihuahuas and Yorkies, the instability is caused by birth defect or injury. Atlantoaxial stabilization is simple and involves placing screws between the vertebrae to connect the spine. But the smaller the dog, the more challenging the precision of the procedure.
“A Chihuahua vertebra is about a centimeter or two and the screws are just millimeters. This leaves a very small corridor of safety during surgery,” said Wood.
The augmented reality program will enable students to manipulate an animated spinal cord and practice this very precise procedure until mastering it.
Wood’s team provided the 3D models and images for the spinal cord, and Lane’s team built an animated replica of it. Working together, the veterinarians and computer engineers then identified the locations to drill on the animated spine. They are currently adding bones and major blood vessels to this virtual piece of anatomy to create a more authentic experience for students.
Once the program is refined and ready, students can simulate a high-risk surgery in a very low-risk way. They’ll use nothing more than a Microsoft HoloLens, a goggle-like headset that projects the spinal cord in real time, and a 3D printed version of the drill used in the surgery.
The Microsoft HoloLens, the 3D printed spinal cord model, and 3D printed version of the drill used in surgery.
“Jonathan and Penn Vet are really thinking of how to innovate and transform education and the veterinary profession,” said Lane. “What’s exciting about their approach is it extends how doctors currently work. Augmented reality uses the same instruments, tools, and devices that doctors regularly use and doctors are seeing what they normally see, but the technology gives additional information that can help them do their job, whether it’s teaching students or treating patients.”
Into the Future
Wood believes Penn Vet’s use of virtual technology will grow and expand. He envisions developing cross-specialty programs or games to help students learn anatomy and understand disease progression. And, in the more distant future, he sees potential for surgeons to use augmented reality during real-life surgeries.
The technology also widens the scope of learning to offer newer veterinary students opportunities to interact with real anatomies and diseases well before they work with patients in the clinic during their fourth year.
“It’s such a unique experience to learn something outside of our normal veterinary school lectures,” said Megan Lin. The third-year Penn Vet student has assisted Wood with designing the augmented reality program and 3D models. “We could watch a video to see a procedure or learn an anatomy part but with these technologies we can really take time to look, touch, and understand.”
