In medical devices there’s a big overlap between QA and RA. In most advanced systems (say, EU and USA for example) QA is a subset of RA in my opinion, because the regulations not only require high quality (and thus all the QA activity), they’re also quite prescriptive in how to go about it. Then, RA has some aspects which don’t come strictly under QA (eg registration). There might be a few exceptions (aspects of QA which are outside RA) depending on how you define Quality and QA, though.