A VCU multidisciplinary team spanning the fields of engineering, computer science and medicine has collaborated to create a virtual environment aimed at improving the skill development, efficiency and cost-effectiveness of surgical training.
Drawing on the expertise of urogynecologist Lauren Siff, M.D., VCU Health adjunct assistant professor, VCU Engineering computer science professor Milos Manic, Ph.D., and his students created a 3D virtual model of a patient’s anatomic structures to train surgeons on how to implant a midurethral sling device. This device alleviates bladder control loss many women experience during physical stress like coughing or laughing.
Implanting the sling is a widely-used procedure where doctors rely heavily on their sense of touch rather than seeing a patient’s internal anatomy. Training focuses on identifying external landmarks and developing muscle memory for proper insertion of the implant.
Siff had been looking to solve the problem of how to teach surgeries that require learning by feel without using cadavers and without practicing on patients. She approached Manic and Franklin Bost, director of innovation at the VCU Institute for Engineering and Medicine, with the idea of creating a virtual simulation for the sling implantation surgery as the first procedure that would use this approach.
Siff, Manic and Bost secured a $75,000 grant from the VCU School of Medicine to develop a prototype training system that uses virtual reality and “haptic” feedback, which mimics the resistance a surgeon feels when pushing into human tissue. Manic and his students got to work writing code and creating the virtual simulation using data from MRI and CT scans, artificial intelligence, and feedback from Siff.
“Dr. Siff will tell you ‘I typically do this’ during the sling procedure,” Manic said. “What the surgeon tells you is really valuable because you want to build that experience into a simulator.”
The “SlingVR” simulator creates a 3D representation of a patient’s pelvis by piecing together two-dimensional images drawn from CT and MRI scans of unidentified patients. A trainee surgeon views that virtual environment on a screen or a VR headset.
“When they see the visualization, they see things moving and it looks smooth. That image constantly changes, and it looks like you’re actually seeing the depth of what’s going on,” Manic said. “But behind all of it is constant number-crunching that’s happening every millisecond to make this look real.”
Beyond looking real, the VCU sling training model is unique because it’s also designed to feel real by providing the doctor touch feedback as they maneuver a device called a trocar through the virtual patient’s anatomy. The technology powering those responses is based on haptics — which pairs what’s seen in virtual reality with a sense of motion or resistance felt in the hands.
In the VR environment, the surgeon uses an actual trocar handle attached to a haptic device that contains motors to create resistance as the virtual trocar presses through the anatomy.
If the trocar collides with the virtual pelvic bone, the instrument creates a rigid push-back response. It provides a more “pliable” feel when touching the bladder and an even slighter response while pressing on simulated blood vessels, the VCU team said in a 2023 International Urogynecology Journal article. The system also provides feedback on distance from critical anatomical structures and will provide “scoring” for levels of proficiency.
Manic became fascinated with haptics technology about 15 years ago while working with colleagues in the robotics field. Some of his early work with haptics included a project through the Idaho National Laboratory training people to use a robotic arm to remotely weld shut barrels containing nuclear waste inside the nuclear reactor.
While fooling a user’s eyes is one thing, integrating the actual feel of conducting a procedure like the midurethral sling takes virtual training to another level, Manic notes.
“It becomes very real at that point if you have a sense of touch,” Manic says.
Performed about 300,000 times a year in the U.S., the sling procedure has a complication rate of up to 13 percent and can lead to perforating the bladder, causing vascular injuries and even death, the 2023 article says.
Team members at VCU and the Central Virginia Health Care System have had a hand in creating and refining the VR training device with an eye towards reducing complications as surgeons hone their skills in a low-risk virtual environment. The project is also aimed at improving upon costly training methods where surgeons have to travel to train for the sling procedure on cadavers.
Siff has given presentations about the SlingVR simulator at numerous conferences, including the 2022 ACS Surgeons and Engineers Conference.
Beyond Manic’s engineering work creating the “proof-of-concept” prototype for the device, the College of Health of Professions is perfecting the SlingVR training technology that VCU officials are seeking to commercialize for a range of potential surgical applications, Bost says. And through Brent Fagg at VCU Tech Transfer and Ventures, a utility patent has also been filed for the technology in the training system.
“Several companies are interested in our prototype system,” Bost said. “We have learned there are other potential surgical applications for the SlingVR technology, not only in URO/GYN surgery, but in other procedures as well.”