I currently have a bachelor's degree in biomedical engineering and soon I will get a Medical Doctor's degree (which technically is a Master's degree). I want to start a PhD after finishing medical studies but I'm more interested in the field of engineering, machine learning and statistics (applied in medicine) than in a purely medical PhD.
My question is can I enroll in PhD program with a main field of engineering/computer science without getting a getting a Master's in engineering, that is, having only the Master's in medicine?
I'm curious both about the formal requirements (how much the fields of Master's and PhD have to match) and the actual chance of succeeding (maybe it's formally possible but usually universities do not allow it). Also, does it depend on the country? I'm especially interested in EU and USA.
I found this question quite relevant although I believe there is a difference. Said question focuses on changing a discipline from field of engineering to another while I'm planning to switch from medicine to an engineering field.