Biomedical refers to the application of the biological, physical and chemical sciences to the study of medical issues. The term is most commonly used in combination with the either the word research or engineer.
A biomedical researcher can work in a wide variety of areas. My own particular field is protein chemistry. I study enzymes. Enzymes are proteins that do things. When enzymes go wrong, they stop doing what they are supposed to do and oftentimes cause disease. Cancers are often caused when enzymes get expressed at the wrong time, or in the wrong place, or with a mutation. Conversely, inhibition of an enzyme activity, such as a key reaction required by a bacterium, can cure a disease. Antibiotics work in this way, and cure bacterial infections.
The study of enzymes and proteins requires many different areas. Enzymology is the study of the enzyme reaction: looking at how the enzyme actually does its job and requires a thorough understanding of chemistry. Structural biology brings state of the art physics and computer science into play to determine how proteins actually look at the molecular level. The production and purification of proteins requires interplay between the sciences of microbiology, cell culture and chromatography. No two proteins behave in exactly the same way; bringing art, experience and intuition into the game. High throughput methods in the new science of combinatorial chemistry allow vast libraries of possible anticancer drug candidates to be made; high throughput screening is then required to see if they work. Bioinformatics the science of compiling and analyzing vast amounts of data holds the whole thing together. Biotechnology is the industry that surrounds biomedical research, and brings the products out of the research labs and into the clinics.
Biomedical engineering is the application of engineering and technology to the field of medicine. The pacemaker and the artificial heart are examples of biomedical engineering. New prosthesis, new implants, new techniques in surgery are the goal of this discipline. New biocompatible materials are needed for such products. New electronic devices put a strain on batteries, driving new technologies in other areas. Advances in imaging techniques, such as magnetic resonance imaging (MRI) are the products of biomedical engineering - of physicians working with physicists.
As progress is been made in the biomedical sciences new questions have arisen that we as a society have not had to face before. Is human cloning is acceptable? Should frozen embryos should be used for research if they are not to be implanted? Is genetic engineering something we should be doing. Questions such as these (and there are many more!) have brought about the new field of biomedical ethics. Practitioners of the biomedical sciences, religious leaders and philosophers as well as lay people all have a role in such a debate.
Biomedical is a lot of things. It is interdisciplinary. It is modern medical science. It is the cure for cancer; the next antibiotic, the next surgical procedure. Many of us already owe our lives to biomedicine. Many more of us will.