By 1997, he told his boss he was closing his lab, effectively putting an end to a nearly two-decade-long academic career in biochemistry. He started traveling to Haiti more often and joined the boards of nonprofits that were active there. The urgency of his previous work paled in comparison. “If people are dying of a treatable disease,” Walmer says, “how important is understanding the biochemistry of the uterine lining right now?” He was convinced that developing a realistic way to screen Haitian women for cervical cancer was the key to keeping his promise to Fertilien, so he continued to putter with his rudimentary colposcope.

“It was pretty crude,” he says. “Most people thought it wasn’t likely to work, but it was very Haitian, where people solve problems in creative ways.”

Word of what Walmer was trying to do eventually reached Bob Malkin, a Duke professor of biomedical engineering who develops medical instruments for third-world hospitals and clinics. (He teaches a course at Duke called Design for the Developing World.) The field is a small one. “When I started in 2001, it was a group of one — and that was me,” he says. But it has grown: In addition to Duke, the University of Michigan, M.I.T., Rice University and others have begun adapting sophisticated medical equipment to address common diseases like asthma and diabetes in poor countries. In 2012, Malkin’s invention, the Pratt Pouch — it looks like a fast-food ketchup packet but contains antiretroviral medication to help prevent pregnant mothers from infecting their newborns with H.I.V. — was named one of the top 10 “innovative health technologies for low-resource settings” by the World Health Organization.

In 2001, when Malkin was a professor at the University of Memphis, he co-founded Engineering World Health, a college club that would eventually expand to dozens of campuses — including Duke, after Malkin joined the faculty there in 2004 — and evolve into a nonprofit company whose focus was improving hospital conditions in developing nations. Every summer, the nonprofit dispatches students in physics, chemistry and engineering to places around the world to fix old medical equipment, set up donated supplies and teach health practitioners how to use them. Malkin also started the Competition for Underserved Resource-Poor Economies (CUREs), which awarded as much as $100,000 to a student-generated business plan for a nonprofit that addressed a medical need in impoverished countries.

Malkin was intrigued when he heard about Walmer’s device. Maybe, he thought, his students could help turn it into a usable tool. “He already had a solution,” Malkin says of Walmer, “but it wasn’t working well.”

The problem was that the device was uncomfortable: It put too much weight on the nose. “We had a working model, but it was too heavy,” Walmer says. “We were dead in the water.” Walmer had become so frustrated that he put the project aside. Malkin suggested that his students might provide fresh eyes, and Walmer agreed. He invited a group of five students to his office to tell them what he had done so far. Recently, for example, his engineering colleague had attached the lights to the end of the lenses, but that hadn’t worked. “We need to move everything back to the forehead, which goes back to the concept of what we first had with the bike-light headband,” Walmer told them. The students were game.