According to section 11 of the Cybersecurity Act, a significant incident means one that has caused or may cause serious disruption to services or significant financial losses to the entity concerned, or one that has affected or may affect other natural or legal persons by causing significant material or non-material damage. This is not an absolutely unambiguous definition of what constitutes a significant incident. The Commission has adopted a separate Implementing Regulation on this for digital service providers (2024/2690). It specifies cases where an incident is regarded as significant, e.g. for cloud computing service providers. Although it may not concern the manufacture of medical devices directly, it is worth having a quick look at the Regulation, as you can get an idea about the thinking behind this for digital service providers. It is also worth debating a potential case with your supervisory authority.