I agree with the two post above. There are set guidelines when it comes to the ownership of the intellectual property. However, documentation is always key when it comes to this issue. I believe that the ownership falls directly to the sponsor of the project. However, if there are any other combinations of ownership. then that should be signed off on before the trial begins. There are generally three ways to categorize IP:
Background Intellectual Property – developed prior to the Study
Study Intellectual Property – developed during the performance of the study
Joint Study Intellectual Property – developed DURINGperformance of the Study by both parties

This can help in the descision of the ownership of side projects that come alone such as the example of Viagra. Some additional question can be asked such as

Who funds the creation of the IP?
Does compound arise from the drug/device?
Who needs exclusive rights/ownership of the IP?
For what purpose(s)?
Who needs non-exclusive license to use the IP?

When IP conditions are sorted out beforehand and agreed on, then the likeliness of future problems decreases.

http://www.healthandtechlaw.com/IP_Rights_in_Clinical_Trial_Agreements