Some thoughts...
1) you need either a unique property or combination of properties...I suspect the latter.
2) questions
a) are the sizes (width,length) always the same
b) color always the same
c) are they grouped or glued to the connector
So, you search all shapes on the page, or possibly just shapes attached to connectors, or all shapes that are not 1D. Then, check each shape to see if there's no text, it's the right color, and the right size. That should be a unique filter set.
Wapperdude