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I want to do some project which in the most direct way affects human beings.
That is honorable and a good motivation. It often takes years though until findings make it to the clinics and achieving this during a student's project is very unlikely. For a student's project you should get in contact with an experienced supervisor who provides you with a managable project that challenges but not overdemands you and can be finished within the given timeframe. The main goal is to learn and improve yourself.
Talk to supervisors at your institution, discuss what you can do, what your interests are and what they could offer. You need guidance to be productive. Learning things alone is tedious, frustrating and not productive imho.