Absolutely! A mechanical-biomedical engineering education will position you for many career opportunities within the medical field. I myself completed a Bachelors in Mechanical Engineering, then pursued graduate school in the Biological Sciences. I attribute a lot of my current employment opportunities to the engineering training that I received as an undergraduate. Mechanical engineering is especially relevant, as the medical industry is always looking for individuals with a broad understanding of biomechanics and/or medical devices. It might be a good idea to explore in what aspects of the medical field you hope to contribute. If you enjoy the clinical side (directly working with patients), then perhaps consider supplementing your engineering education with some human biology coursework and hands-on experience (internships or volunteering). If you enjoy the technology side (designing and building), then definitely pursue some internship experience at medical device companies. As for your current switch from chemical to mechanical engineering, not to worry, you'll be just as successful. Good luck!!