Meisenheimer knows his patients know about his obsession.
"It's pretty hard to walk in my waiting room and not," he said pointing out posters and displays of yo-yos. "I think everybody knows my love for yo-yos."
Meisenheimer has more of them than anyone else in the world. Part of his house has been turned into a museum-quality display of roughly 3,000 yo-yos. One dates back to 1790 in Britain. Another can be dipped in kerosene and lit on fire. Another has an internal compartment with teeth - it's meant for medical marijuana users to shred up their pot.
There are more in boxes in the attic. The total may be 10,000. He's lost count.
"It's such a piece of Americana," Meisenheimer said. "And it's the Nintendo of the 1930s, 40s, 50s, and even in the 60s. That was the toy."
Even today Meisenheimer toys with his acquisitions; he shows Schlesinger a trick.
In the process of collecting all these yo-yos Meisenheimer has made a serious study of them as well. He's now the chairman of the history and collecting committee of the American Yo-Yo Association. (Yes, there is one.) And he wrote the book on Yo-yos that's on display at the Smithsonian.
Dr. Meisenheimer has made his place in yo-yo history with not only the largest known yo-yo collection - but also the largest known yo-yo. It's about the height of a man and stands in his yard. He founded it on EBay; it had to be delivered by forklift.
Schlesinger gives Meisenheimer a one more for his collection: a yo-yo bearing the CBS logo.
So now the number of the Meisenheimer collection is about 10,001.