BIOENGINEERING

the application of engineering knowledge to the fields of medicine and biology. The bioengineer must be well grounded in biology and have engineering knowledge that is broad, drawing upon electrical, chemical, mechanical, and other engineering disciplines. The bioengineer may work in any of a large range of areas. One of these is the provision of artificial means to assist defective body functionssuch as hearing aids, artificial limbs, and supportive or substitute organs. In another direction, the bioengineer may use engineering methods to achieve biosynthesis of animal or plant productssuch as for fermentation processes. application of engineering principles and equipment to the biological and medical sciences. It includes the development and fabrication of life-support systems for underwater and space missions, machines for medical treatment (e.g., heartlung machines), and instruments for monitoring biological processes. Of relatively recent origin, bioengineering has provided some of the most remarkable breakthroughs in medical science. Prosthetic limbs have been developed that can replace or augment normal functions; such prostheses are equipped with the ability to move and to operate by touch feedback. Development has been particularly rapid in the area of artificial organs, which culminated in the implantation of an artificial heart into a human being (1982). Two of the most common examples of artificial organs are the artificial kidney and the heartlung machine. An artificial kidney, or hemodialyzer, is used for those with chronic kidney malfunction, and a heartlung machine is used to oxygenate the blood when the lung or heart muscles, or both, cannot. There are other mechanical devices used to aid heartbeat and blood circulation, such as pacemakers. Bioengineering also has proved pivotal in the development of elaborate life-support systems that enable humans to maintain body functions in hostile environmentsi.e., no oxygen, extremes of temperature and pressure, and so on. One such system is the space suit worn by astronauts during extravehicular maneuvers. This type of suit is a self-contained environment that supplies everything needed to sustain life. It provides a pressurized interior, without which an astronaut's blood would boil in the vacuum of space. In addition, the space suit provides oxygen, a means for removing excess products of respiration (i.e., carbon dioxide and water vapour), protection against extreme heat, cold, and ionizing radiation, and facilities for temporarily storing body wastes. Additional reading Several of the major branches of bioengineering are treated in the following reference works: Richard Skalak and Stu Chien (eds.), Handbook of Bioengineering (1987); Jacob Kline (ed.), Handbook of Biomedical Engineering (1988); A. Edward Profio, Biomedical Engineering (1993); R.H. Brown (ed.), CRC Handbook of Engineering in Agriculture, 3 vol. (1988); Bernard Atkinson and Ferda Mavituna, Biochemical Engineering and Biotechnology Handbook, 2nd ed. (1991); Wesley E. Woodson, Barry Tillman, and Peggy Tillman, Human Factors Design Handbook: Information and Guidelines for the Design of Systems, Facilities, Equipment, and Products for Human Use, 2nd ed. (1992); Mark S. Sanders and Ernest J. McCormick, Human Factors in Engineering and Design, 7th ed. (1993); Alphonse Chapanis, Human Factors in Systems Engineering (1996); Robert A. Corbitt (ed.), Standard Handbook of Environmental Engineering (1990); P. Aarne Vesilind, J. Jeffrey Pierce, and Ruth F. Weiner, Environmental Engineering, 3rd ed. (1994); and James R. Pfafflin and Edward N. Ziegler (eds.), Encyclopedia of Environmental Science and Engineering, 3rd ed., rev. and updated, 2 vol. (1992). The Editors of the Encyclopdia Britannica