I went to grad school for architecture at the end of the last century.

Tim was a classmate. He was and remains paralyzed from the neck down. At the computer Tim manipulated a trackball with a tool — rod connected to a flat mouth piece.

This is different, but I am not sure it is better. The trackball and stick were mostly mechanical, reliable, and straightforward to repair.

No special software. No need to charge. Tim’s tools were as reliable as a mouse. Not much of a choking hazard because of the stick either.

I’m not saying the mouth-pad is a toaster fridge. Only that it has technical complexity rather than mechanical simplicity.