I have found out that the mechanical screening technique used by the Motley Fool Hidden Gems service found Atrion a number of years ago and it has been the portfolio (Mechanical Screen) for a number of years with excellent results.
This is a special board called Hidden Gem Screening. There is a very interesting individual there who has developed a mechanical screening technique. One of the things it looks for is improving profits and margins in recent quarters.
I have my own screening techniques that identified ATRI.