The new EU Regulation on in vitro diagnostic (IVD) medical devices will not apply until May 2022, which is outside of the implementation period. However, elements of both new devices regulations have applied directly in UK law since May 2017, meaning medical devices, including IVDs, can now be legally placed on the UK market if they are in conformity with the new regulations, invoking all relevant requirements.

https://www.gov.uk/government/publications/implementation-period-what-it-means-for-the-life-sciences-sector/what-the-implementation-period-means-for-the-life-science-sector