Who is responsible for making the initial risk determination for a device being used in a study?

The Sponsor-Investigator

Explanation: It is the sponsor-researcher who is in charge, as this is one of his primary duties. When conducting an investigation where the sponsor-researcher as such bears the costs and is the one who directs it, with the support of his colleagues and, of course, a group of collaborators, it is critical that the protocols required by local ethics as well as international standards of research are followed.