[Introduction] Article 61(4) of Regulation (EU) 2017/745 on medical devices (MDR) requires clinical investigations to be performed for implantable and class III devices, except in four specific cases as outlined in: CASE 1) indents 1-3 of Article 61(4); CASE 2) Article 61(6)(a); CASE 3) Article 61(6)(b); CASE 4) Article 61(5). These four cases which are exempted from the requirement to perform c..