Biomedical Engineering field and study question?

the career that allows you to create medical machines that help in the detection/fight against cancer and deadly diseases. Also the career that allows you to, in a way, engineer a cell to fight against certain cancers and diseases. i know its more of a biomedical/technology career...but more along the lines of what branches are more ociated with these workings? And if they are separated branches, would you have to obtain 2 degrees to work on both paths?