Between the ages of 13 - 18 I was inlisted into servitude at my father's medical practices (2)...So that's where the "Dr" comes from.
One sunny Saturday out in the desert office, a call came in that a guy had injured his thumb while running his motorcycle into a Joshua tree. He reported to me that he thought "it may be broken!"....[I hate gushy blood streaming from lifeforms, and I had a pact with my father, if it was bloody, I was OUT!].
He came in to the office and I put him in a room, and started to unwrap his makeshift bandages. When I got to the hand, well, yeah, there it was....his thumb was hanging off his arm held to the hand by only a tendon...blood and bones and flesh gushing about like a fish out of water. I saw his bones....
I told this story to a guitarist of many years and bands together....He's the one that spoke that word after I told him the story. He and I were messing around on my garage computers and I showed him ThinkTanks. Being it was shortly after that story and about 20 buckets of tears from laughter when he uttered "DrSawbones"....he entered "DrSawbones" as the screen name and played all night. It became the garage machine's ThinkTanks standard screen name for anyone who played in the garage that summer....I decided to ask him if it was okay to keep it forever...and he agreed.

Dr+Saw+bones= DrSawbones