Robotics Lends a Helping Hand

In 2019, a horrible accident upended Payton Heiberger’s life. When her car was struck on the driver’s side by an out-of-control vehicle, the violent impact severed her left thumb and a finger. “I knew instantly that it was a disaster,” the Houston, Texas, student told the Boston Globe.

When prosthetics companies could offer her only cosmetic replacement fingers that don’t move, she rejected them. “I don’t see the point in making it just look normal,” says Heiberger, a junior on a pre-med track at the University of Houston who dreams of becoming a plastic surgeon. “I want to use it for mobility and structure and have it be useful.”

Thanks to a creative team of engineering students at WPI, that vision may finally be in sight.

The team, Mia Buccowich ’22 (biomedical engineering), Brian Fay ’22 (mechanical engineering), and Andy Strauss ’23 (robotics engineering), designed a partial-hand prosthesis for Heiberger as their Major Qualifying Project (MQP), a professional-level research or design project all WPI undergraduates must complete. The project was advised by Marko Popovic, assistant research professor of robotics engineering, who heard about Heiberger’s situation from personal contacts.

“The glaring thing to me was that while there are some partial hand prostheses,” Strauss says, “the ones that do exist don’t work for Payton’s specific injury, which is why her parents reached out to our lab.”

With a plaster mold of Heiberger’s injured hand and a laser scan of her good hand to provide a reference for how long and thick to make the fingers, the team went to work. With the goal of replacing some of the functionality of Heiberger’s fingers, Buccowich focused on sensing and actuation aspects of the prototype, Strauss designed the mechanical components, and Fay worked on a wrist band that will house the actuator for thumb movement and a small solenoid that locks it in place. Sensors that Heiberger can press with the remaining portion of her thumb will allow her to move the prosthetic thumb forward and backward.

As they developed concepts for the device and began to build prototypes, the students spoke regularly with Heiberger by phone and Zoom. One of the ongoing challenges they faced was finding the best way to integrate the device with her hand. “Making the finger prostheses is relatively easy,” Strauss says. “The hard part is figuring out how to attach fingers to the person’s partial hand.” He notes that the team sought to design “a system that can connect any kind of prosthesis to a person’s hand.”

Heiberger visited WPI in December 2020 and in April 2021 to meet Popovic and the student team and to try on their prototypes. After testing the team’s fourth iteration in April, she was heartened by their progress, but also struck by a nagging question: “How do you stabilize it with these knuckles moving and keep everything in the same spot?” she asked. “So that’s what we’ve been tackling recently.”

The WPI students, who applied for a provisional patent for their design, will hand the project off to another MQP team that will make any final adjustments to the technology.

“We’re all invested in Payton and invested in making sure this works,” Buccowich said as the academic year wound down. “Our goal is to have a prosthesis for her by the end of the school year, but we will continue perfecting it until she is happy with it.”

“The WPI team has been amazing,” Heiberger says. “I feel like I’ve grown as a person and I owe a lot of that to working with Andy, Mia, and Brian. It’s unbelievable to me that I’ve been able to meet people my age working on such an important project. I’m really grateful for our partnership and friendship.”