what a-levels should I do for biomedical engineering?

Biomedical engineering often has slightly wider admissions subjects versus other engineering subjects, there are courses today that don’t require physics A-level. Although it is a bit of a niche (although it does seem to be growing in popularity.. but still a small area).

Id be inclined to advise taking physics if you want to pursue engineering as it will give you more options and you’ll be restricted without it, and id bet people in industry regarding biomedical applications more commonly have mechanical, materials, manufacturing, chemical engineering backgrounds.