Co-authors that quit during software development and such software is using later in a patent, should they be added as coauthors/inventors?

Question

We have a situation in which we developed some software, where four previous members of our research group participated some time ago. Then they left the group, and said that from then on, they did not want to work on further developments of the code.

Now we have used that code, which has evolved a bit since they left, and we have applied it to some other contexts, in which we have made some discoveries, and it turns out we can file a patent.

The question here is, the old members that left the group and did not want to work on further developments of the code, must they be included in the patent as authors/inventors?

I would say the answer is no, since they said they did not want to work on further developments of the code, but since this software tool was a key step for the discovery reported in the patent, and they participated a bit in the past on the software, they should perhaps be included as coauthors/inventors.

Should they be included?

Answer 1

Inventorship isn't like authorship where all significant contributors are listed. To be considered an inventor you need to provide a conceptual contribution to at least one claim. So the question is looking at each claim did any of the old members contribute the the concept contained in that claim. If so, the person should be added as an inventor on the patent. For example, let's say person A has an idea for a new algorithm and asks person B implements the algorithm in code. Assuming person B doesn't modify or extend the algorithm, then person A is considered the inventor if a patent claim includes the algorithm but not person B. This is true despite the fact that person B might spend a greater effort and time on the development of the code. If however person B improves the algorithm in a way reflected in a claim, the they both are inventors. This answer might provide a bit more clarity.

Answer 2

In the US you need to include anybody who has contributed to any of the claims in your application. Not doing so could possibly invalidate the application. https://www.ipwatchdog.com/2020/10/12/getting-a-patent-who-should-be-named-as-an-inventor/id=126026/

If you file for additional claims, you should be able to add an inventor to subsequent claims so long as there is at least one inventor in common on the subsequent application. https://www.smartuplegal.com/learn-center/can-you-add-another-person-to-your-patent-application/