Design and conquer

At what point does a knitting pattern become your own?  I'm working on Sehlat's

birthday socks and I wanted to make something unique.  I'm using two elements from

different patterns, and making a few of my own changes.  Far as I know no-one's assembled this set of features before.  It's looking pretty cool as socks go, all jewel tone

Sockotta yarn.  I'm planning to put the pattern together as my first sock design and

attribute the heel and toe to their proper inventors.  Does that count as my overall

design?