Don and Joyce Harvey were generous folks before they won the Powerball lottery and became millionaires five years ago. Money didn’t change their will to help others. It just meant that now they can help even more. A recent donation by the eastern Oklahoma couple will help University of Oklahoma Medical Center doctors buy and operate a mobile research unit that will study diabetes in children who live in rural areas. The gift was announced Friday at OU Health Sciences Center. The mobile unit is the size of a recreational vehicle and should be ready to travel next year to rural Oklahoma. "Our goals are to find the causes and cures of childhood diabetes,” said Dr. Steven Chernausek, director of the CMRI Diabetes and Metabolic Research Program. Chernausek said children in rural areas usually don’t have access to specialists and often can’t participate in research done in Oklahoma City. Don Harvey, a former truck driver, said that before winning the lottery, his biggest investments were tires for his big rig. Now he said he feels like "helping the world is our investment.” Joyce Harvey, a member of the Cherokee Nation, said she’s concerned about the number of American Indian children at risk for diabetes. "It’s a blessing we are able to help people,” she said. "Children are our future. We don’t want them dying at early ages.” The mobile unit will cost $800,000 or more. The Harveys have given an initial donation of $30,000 and plan to give more. The couple have helped with other medical causes, buying wheelchairs for their local physician and donating to a rural hospital. They created a nonprofit organization, the DJH Foundation, to raise more money for philanthropic projects. The Harveys’ generosity will be featured on The Learning Channel next week. The episode is scheduled to air at 7 p.m. Wednesday on the cable network’s series "The Lottery Changed My Life.” The Harveys didn’t say where they live in eastern Oklahoma because they’ve been harassed so much since winning the lottery ticket valued at $105 million. They took the lump sum option and after taxes netted about $33 million. Instead of working, Don, 67, and Joyce Harvey, 52, travel the nation in a 45-foot-long recreational vehicle, spending time at all the destinations they had to drive by before winning the lottery. "They are very generous people with very generous hearts,” said the couple’s attorney, David Walls.