This is the best armrest we designed at Earthlite. The armrest can adjust
to the width of the person even though the seat is much wider. The armrest
remains horizontal when the back of the table is lifted. The armrest can be
removed from the chair. There is a version of the armest with a manicure bowl.

The armrest mechanism has a fixed part and a detachable part.
There are one horizontal pivot and 2 or 3 vertical pivots.
Here is the patent for this product.

Book by William Chow

Clinicon Surgical Laser System

State-of-the-art headrest (2006 & 2007)

Convert-A-Bed, new product Nov. 2008

William Chow product design