The 510(k) should demonstrate that the device is substantially equivalent to the chosen predicate (and any differences justified).
So, somewhere in the submission, there will generally be a comparison table showing the various details (indications for use, operation, power-supply, technology, materials..etc. etc.) of the device and predicate side-by-side.
The more similarities (i.e. the more items that can be stated as "same" between the new device and predicate), the easier the process, as there are fewer differences to justify.
I presume you've looked at the
FDA Guidance on this? That's a good starting point.
I also suggest requesting a copy of the predicate 510(k) under FOIA, as this can make comparison much easier...
Hope that helps somewhat...
MM