Greg Wulffen

In theory, taking an EKG just requires placing small plastic-tipped electrodes on a patient’s skin to detect electrical impulses from the heart. But the procedure becomes far more complex when the patients are active, curious chimpanzees—who suffer from similar heart conditions to humans.

The challenge facing Greg Wulffen and his team: Design an EKG tool that could be used on chimps at the Maryland Zoo—or, rather, used by the chimps themselves.

“The first thing we did when tackling this project was to think of all the ways a chimp might try to destroy it, and focus in on that,” said Wulffen, who earned a bachelor’s degree in mechanical engineering from JHU in 2024 and is now pursuing a master's degree in engineering management.

Using Computer-Aided Design (CAD) software, Wulffen came up with a sheath made of Delrin—a thermoplastic that has a high-fracture toughness—that slides over a cut-out in the center for the electronics and coated the handles with copper. The team then made the entire device wireless, using Bluetooth, and refined the interface so a zookeeper could easily decode and extract the EKG data.

After the zoo confirmed that all materials were safe, the time came to try out the device on the intended subject: an energetic chimpanzee.

“The first run-through overall went well, and we got a reading from one of the chimps,” says Pam Carter, area manager for the Chimpanzee Forest at the Maryland Zoo. “I think we’re the only place getting EKGs this way.”