Where could you find biomedical engineers working at?

Companies that hire biomedical engineers include those that, obviously, design and implement medical devices. One very simple approach would be to stop in a doctor's office and talk to the receptionist and ask if they would leave a note for the doctor to ask for a few minutes. The doctor usually knows several companies that make the devices they use. Ask for a contact. Most salespeople are very willing to talk to anyone interested in their products and field. They also may be willing to simply pass your note onto folks in the profession that they do business with. And companies that make these devices would likely be very willing to pass on your request. My basic approach is that when you want to find out about a particular job, simply find a way to contact those people working in it. Bear in mind that most people that tackle a particular technical profession and stick with it are more than willing to talk your ear off about what they do, because it's often a labor of love, as it were. Go for it!