Biomedical engineering is application of traditional engineering principles and design procedures to analyze and solve problems in biology and medicine. Biomedical engineers may be called upon in a wide range of capacities, including designing instruments, devices and software; bringing together knowledge from many technical sources to develop new procedures; and conducting research needed to solve clinical problems.
Subdisciplines of Biomedical Engineering
Although a number of subspecialty areas of biomedical engineering exist, they rarely “work in a vacuum.” Often, the biomedical engineer who works in one area will use knowledge gathered by biomedical engineers working in other areas. For example, the design of an artificial hip is aided greatly by studies on anatomy, bone biomechanics, gait analysis and biomaterial compatibility. The forces applied to the hip can be considered in the design and material selection for the prosthesis. Similarly, the design of systems to electrically stimulate paralyzed muscle to move in a controlled way uses knowledge of the behavior of the human musculoskeletal system. The selection of appropriate materials used in these devices falls within the realm of the biomaterials engineer.
This involves developing and using computer tools to collect and analyze data related to medicine and biology. Work in bioinformatics could involve using sophisticated techniques to manage and search databases of gene sequences that contain millions of entries.
This is the application of electronics and measurement techniques to develop devices used in diagnosis and treatment of disease. Computers are an essential part of bioinstrumentation, from the microprocessor in a single-purpose instrument used to do a variety of small tasks to the microcomputer needed to process the large amount of information in a medical imaging system.
These include both living tissue and artificial materials used for implantation. Understanding the properties and behavior of living material is vital in the design of implant materials. The selection of an appropriate material to place in the human body may be one of the most difficult tasks faced by the biomedical engineer. Biomaterials must be nontoxic, noncarcinogenic (not cancer-causing), chemically inert, stable and mechanically strong enough to withstand the repeated forces of a lifetime. Newer biomaterials even incorporate living cells to provide a true biological and mechanical match for the living tissue.
This applies classical mechanical engineering to biological or medical problems. It includes the study of motion, material deformation, flow within the body and in devices and transport of chemical constituents across biological and synthetic media and membranes. Progress in biomechanics has led to the development of the artificial heart, heart valves and artificial joint replacements, as well as to a better understanding of the function of the heart, the lungs, blood vessels, capillaries and the bone, cartilage, ligaments and tendons of the musculoskeletal systems.
Microelectromechanical systems (MEMS) are the integration of mechanical elements, sensors, actuators and electronics on a silicon chip. BioMEMS are the development and application of MEMS in medicine and biology. Examples of BioMEMS include the development of microrobots that one day might perform surgery inside the body and the manufacture of tiny devices that could be implanted inside the body to deliver drugs on demand.
This involves extracting useful information from biological signals for diagnostics and therapeutics purposes. This could mean studying cardiac signals to determine whether a patient will be susceptible to sudden cardiac death, developing speech recognition systems that can cope with background noise or detecting features of brain signals that can be used to control a computer.
This is a set of powerful tools that employs living organisms (or parts of organisms) to make or modify products, improve plants or animals or develop microorganisms for specific uses. Some of the earliest efforts in biotechnology involved traditional animal and plant breeding techniques and the use of yeast in making bread, beer, wine and cheese. Modern biotechnology involves the industrial use of recombinant DNA and cell fusion, novel bioprocessing techniques that can be used to help correct genetic defects in humans. It also involves bioremediation, the degradation of hazardous contaminants with the help of living organisms.
Cellular, Tissue, and Genetic Engineering
This involves more recent attempts to attack biomedical problems at the microscopic level. These areas utilize the anatomy, biochemistry and mechanics of cellular and subcellular structures to understand disease processes and to be able to intervene at very specific sites. With these capabilities, miniature devices deliver compounds that can stimulate or inhibit cellular processes at precise target locations to promote healing or inhibit disease formation and progression.
This is the application of technology to health care in hospitals. The clinical engineer is a member of the health care team along with physicians, nurses and other hospital staff. Clinical engineers are responsible for developing and maintaining computer databases of medical instrumentation and equipment records as well as for the purchase and use of sophisticated medical instruments. They also might work with physicians to adapt instrumentation to the specific needs of the physician and the hospital, which often involves the interface of instruments with computer systems and customized software for instrument control and data acquisition and analysis. Clinical engineers are involved with the application of the latest technology to health care.
This combines knowledge of a unique physical phenomenon (such as sound, radiation or magnetism) with high-speed electronic data processing, analysis and display to generate an image. These images often can be obtained with minimal or completely noninvasive procedures, making them less painful and more easily repeatable than invasive techniques. In addition, radiology refers to the use of radioactive substances such as X-rays, magnetic fields and ultrasound to create images of the body, its organs and its structures. These images can be used in the diagnosis and treatment of disease, as well as to guide doctors in image-guided surgery.
Microtechnology and Nanotechnology
Microtechnology involves the development and use of devices on the scale of a micrometer (one thousandth of a millimeter, or about 1/50 of the diameter of a human hair), while nanotechnology involves devices on the order of a nanometer (about 1/50,000 of the diameter of a human hair, or 10 times the diameter of a hydrogen atom). These fields include the development of microscopic force sensors that can identify changing tissue properties as a way to help surgeons remove only unhealthy tissue and nanometer-length cantilever beams that bend with cardiac protein levels in ways that can help doctors in the early and rapid diagnosis of heart attacks.
Neural Systems and Engineering
This emerging interdisciplinary field involves study of the brain and nervous system and encompasses areas such as the replacement or restoration of lost sensory and motor abilities (for example, retinal implants to partially restore sight or electrical stimulation of paralyzed muscles to assist a person in standing), the study of the complexities of neural systems in nature, the development of neurorobots (robot arms that are controlled by signals from the motor cortex in the brain) and neuroelectronics (developing brain-implantable microelectronics with high computing power, for example).
This is the specialty where methods of engineering and computational mechanics have been applied for the understanding of the function of bones, joints and muscles and for the design of artificial joint replacements. Orthopedic bioengineers analyze the friction, lubrication and wear characteristics of natural and artificial joints, perform stress analysis of the musculoskeletal system and develop artificial biomaterials (biologic and synthetic) for the replacement of bones, cartilages, ligaments, tendons, meniscus and intervertebral discs. They often perform gait and motion analyses for sports performance and patient outcome following surgical procedures.
This is a growing specialty area of biomedical engineering. Rehabilitation engineers enhance the capabilities and improve the quality of life for individuals with physical and cognitive impairments. They are involved in prosthetics, the development of home, workplace and transportation modifications and the design of assistive technology that enhance seating and positioning, mobility and communication. Rehabilitation engineers also are developing hardware and software computer adaptations and cognitive aids to assist people with cognitive difficulties.
Robotics in Surgery
This includes the use of robotic and image processing systems to interactively assist a medical team both in planning and executing a surgery. These new techniques can minimize the side effects of surgery by providing smaller incisions, less trauma and more precision, while also decreasing costs.
This is the term used to describe the aspect of biomedical engineering in which engineering strategies, techniques and tools are used to gain a comprehensive and integrated understanding of the function of living organisms, ranging from bacteria to humans. Computer modeling is used in the analysis of experimental data and in formulating mathematical descriptions of physiological events. In research, predictor models are used in designing new experiments to refine our knowledge. Living systems have highly regulated feedback control systems that can be examined with state-of-the-art techniques. Examples are the biochemistry of metabolism and the control of limb movements.
A biomedical engineering degree typically requires a minimum of four years of university education. Following this, the biomedical engineer may assume an entry level engineering position in a medical device or pharmaceutical company, a clinical engineering position in a hospital or even a sales position for a biomaterials or biotechnology company. Many biomedical engineers will seek graduate-level training in biomedical engineering or a related engineering field, pursue a graduate degree in business or apply to medical or dental school. A fraction of biomedical engineers even choose to enter law school, planning to work with patent law and intellectual property related to biomedical inventions.