I've thought about that, but, most of the stock images I've looked at don't have much on the walls...maybe a diploma or something. Here are some reference images: http://www.gettyimages.com/creative/examination-room-stock-photos
I'm thinking of the exam room as one of many at a clinic, so multiple doctors could use this room...which would mean no individual diplomas. Also, the lack of things on the walls will reduce the chance of bad tangents.