Clara Frias was in the final year of a 5-year degree program in mathematics at the University of Trás-os-Montes and Alto Douro  in her native Portugal when she broke her foot in a small accident. It took her a year to recover fully, and the experience prompted her to switch from mathematics to biomedical engineering. "I got ... enthusiastic with orthopedics and all these things," Frias says. After graduating in 2004, she entered a Ph.D. program in biomechanical engineering  at the University of Porto , working to improve implants for hip replacement.
Since then, Frias, who is now 29, has developed a medical device designed to monitor the performance of hip implants in real time -- alerting doctors to postsurgery problems -- and to stimulate bone growth on the implant's surface. The device, which Frias is testing in animals during a postdoc at the Institute of Mechanical Engineering and Industrial Management  in Porto, has yielded six peer-reviewed papers, a patent, and increasing attention from the medical community.
Because of their pragmatic, problem-solving orientation and multidisciplinary exposure, biomedical engineers like Frias are playing a crucial role in the development of bench-to-bedside technology -- a trend that is likely to continue, says Marco Viceconti, technical director of the Medical Technology Laboratory  at the Rizzoli Orthopaedic Institute  in Bologna, Italy, and chair of the European Alliance for Medical and Biological Engineering & Science  (EAMBES). "There is definitely a growing space for biomedical engineering science."
Biomedical engineering is very broad, combining engineering techniques with human biology to develop medically relevant technologies. Research in the field has focused on prosthetic limbs, hip and knee replacement devices, rehabilitation technologies, assistive technologies such as hearing aids, medical imaging technologies, and biomedical instrumentation, but the field is constantly spreading into new areas. "There is an enormous spread of potential applications," Viceconti says.
As biomedical devices get more sophisticated, biomedical engineers must draw on more and more disciplines. One problem with traditional hip implants is that over time they can loosen or cause bone damage by wear and tear, causing pain and requiring repeat surgeries. Frias's device includes a network of sensors and actuators placed on the implant during surgery. Controlled wirelessly, the device will allow physicians to monitor the bone-implant interface after surgery while stimulating bone growth. Developing the device has required the collaboration of mechanical engineers, physicists, biologists, and clinicians, Frias says.
Other biomedical engineers are developing a new generation of prosthetic limbs that amputees can control with neurosensors, with assists from computer science, neuroscience, and electrical and mechanical engineering, among other disciplines. One example is Alícia Casals, a professor at the Technical University of Catalonia  and head of the Robotics group at the Institute for Bioengineering of Catalonia  in Barcelona, who works with a type of robotic prosthetics known as exoskeletons. The exoskeletons are placed on missing or dysfunctional limbs, where they sense patients' will to move and assist them in doing so to help patients train their muscles (and related brain regions) during rehabilitation. An engineer and computer scientist by training, Casals is developing software to make these robotic exoskeletons "intelligent enough to interact with humans and try to complement the humans' abilities," she says.
Meanwhile, Viceconti, who holds a mechanical engineering degree and a Ph.D. in the design of medical devices, specializes in computational biomechanics. He makes patient-specific models of bone segments and simulates their interaction with orthopedic devices. Other biomedical engineers work in cellular, tissue, and genetic engineering and develop artificial organs and biomaterials. "Engineering principles are relevant to the understanding of how the tissue will work in vivo or how the machine we use to grow the tissues works in bioreactors," Viceconti says.
The body of scientific knowledge and skills needed to work in biomedical engineering is just as diverse as the range of research topics. "Anyone can enter because the field is so wide," Casals says, noting that the field benefits when people enter it from different directions. Nowadays, many universities offer bachelor's, master's, and Ph.D. programs in biomedical engineering, but some experts suggest that, on the contrary, medical and biological engineering should be "seen as a sort of specialization that occurs after you have a solid education in physics and engineering," Viceconti says. No matter how you get in, the most important skill is "to be open to ... working in different fields," Casals says.
That certainly was Frias's experience. Every step in her Ph.D. research was a departure from her training in mathematics. She learned about electronics and optical electronics to assess what kinds of sensors and circuits would work best for her hip device. She carried out mechanical tests to simulate hip joints in locomotion, and she ventured into materials science to develop composite materials that could stimulate the growth of bone tissue. She then had to grasp biology sufficiently to test the biocompatibility of these materials in animals. And she had to work with bone cells to see how they would react to contact with the material and to determine what level of microvibration would best stimulate cell growth.
To ease the transition from mathematics to biomedical engineering, Frias studied mechanical engineering at the Engineering Faculty of Porto University  for a year before beginning her Ph.D. She picked up her other skills and knowledge by taking classes, reading the literature, interacting with colleagues in the lab, and networking with other research groups.
Working with scientists in and out of your lab is especially important, Frias says, which places great demands on communication skills. "The other communities have a different language and different ways of thinking, different ways of doing [things], and it's really difficult," Casals says. Also important is a holistic, patient-focused approach -- even if biomedical engineers rarely work directly with patients. "Don't think only about the software, only about the machine, only about the specific facts, but just on the whole system," Casals says.
Experience in technology transfer is also valuable. A couple of years ago, Frias took part in the COHiTEC program , offered by the Portuguese business association for innovation, COTEC Portugal . The program offers courses and mentoring to teams of researchers and MBA students to help them turn research results into business opportunities. The course "gave me a big vision to understand all the steps going from the research to the application of this research to help people," says Frias, who hopes to start a company or sell her hip technology to a biomedical device company.
The chief advantage of biomedical engineering is also its main disadvantage: It sits at the intersection of several disciplines. If you are a biomedical engineer developing scaffolds to grow cartilage for regenerative medicine, you are unlikely to publish in top biology journals because your research is not viewed as fundamental, Viceconti says. It may even be difficult to get such work into traditional engineering journals, because "still today there is a resistance in the traditional engineering community to consider this as part of engineering," though that is changing, he says.
On the other hand, "it is unquestionable that the funding opportunities, the career opportunities are much [greater] in these interdisciplinary areas than in the more established and traditional areas," Viceconti continues. The U.S. Bureau of Labor Statistics projected  a growth of more than 70% over 10 years in the number of biomedical engineering positions -- up from 16,000 in 2008. In Europe, new centers such as the Institute of Biomedical Engineering  at Imperial College London and the Institute of Biomedical Engineering  (IBME) at the University of Oxford in the United Kingdom provide a multidisciplinary environment in which scientists, engineers, and clinicians can work together to apply scientific advances to health care. "You have to fight and work well to get funds and to get jobs, but it's a promising ... and expanding area," Casals says.
Training in biomedical engineering provides options beyond the academic world, too. Opportunities are growing for biomedical engineers in industrial research, and biomedical engineers are increasingly finding jobs in hospitals, where they oversee the acquisition, safety, and maintenance of medical technologies, Viceconti says. And "if ... you undertake a research career and then after a while you realize for some reason this is not what you want, well, you're still an engineer, so you have a lot of industrial opportunities for redesigning your career path."
Another disadvantage to biomedical engineering research is that it may take longer for work to come to fruition than in other, simpler fields. Also, many projects will fail. It can be "discouraging how slowly we advance because the needs are big," Casals says. Yet those big needs -- the need and opportunity to improve people's health and quality of life -- can lead to great professional satisfaction when they are met, she says.
Meanwhile, there are many smaller sources of satisfaction as you wait for the work to mature. When Frias started getting in touch with clinicians at the beginning of her Ph.D., they limited themselves to wishing her good luck, she recalls. But as her work was published, clinicians started calling her to see how they could collaborate. Clinicians want "to really understand and help us understand how we can get this work more appropriate for application in humans," Frias says.
Finding out more about the field
- The Engineers section  of the U.S. Bureau of Labor Statistics's Occupational Outlook Handbook
- The IEEE Engineering in Medicine and Biology Society , which published a review article on
- The U.S. National Science Foundation's report on The Emergence of Tissue Engineering as a Research Field 
- The U.S. Biomedical Engineering Society  (BMES)
- The Biomedical Engineering Career Alliance  in the United States, which promotes interactions with industries
- The American College of Clinical Engineering  (ACCE)
- The European Alliance for Medical and Biological Engineering & Science  (EAMBES)
- The Association of Institutions Concerned with Medical Engineering  in the United Kingdom
- The Bio Innovations and Opportunities in Medicine and Engineering  (BIOME) program at the University of Wisconsin, Madison, for graduate students
- Training programs  in the biomedical imaging and bioengineering fields at the U.S. National Institute of Biomedical Imaging and Bioengineering (NIBIB) (and list of extramural opportunities offered by the U.S. National Institutes of Health)
- You can search  for accredited degree programs in the United States and other parts of the world in bioengineering and biomedical engineering on the Leadership and Quality Assurance in Applied Science, -Computing, Engineering, and Technology Education ABET Web site 
- M.Sc. program  in Biomedical Engineering at Imperial College London
- Centre for Doctoral Training in Healthcare Innovation  at the Institute of Biomedical Engineering (IBME) at the University of Oxford
- The U.S. National Science Foundation (NSF) Biomedical Engineering (BME) program in neural engineering and cellular biomechanics
- The Whitaker Foundation  has been instrumental in the development of biomedical engineering in the United States and now offers grants  to strengthen collaborations between young leaders in biomedical engineering worldwide
- The Wellcome Trust-Massachusetts Institute of Technology (MIT) Postdoctoral Fellowships  to support research at the interfaces between biology, medicine, mathematics, engineering, computer, and physical or chemical sciences and other biomedical science grants 
- European Commission funding for health research 
Photo (top): A "smart hip" developed by Clara Frias that reduces the number of surgical interventions and regenerates bone tissue in the hip area. (Faculty of Engineering, University of Porto)
Elisabeth Pain is contributing editor for South Europe.