Adaptation was nothing new in medicine, and physicians always seemed ready to find new uses for technology's latest offspring. Lasers are perhaps the best case in point. Not long after its invention, the laser was taken up by the medical profession and became one of the most effective surgical tools of the 20th century's last 3 decades. Lasers are now a mainstay of eye surgery and are also routinely employed to create incisions elsewhere in the body, to burn away growths, and to cauterize wounds. Set to a particular wavelength, lasers can destroy brain tumors without damaging surrounding tissue. They have even been used to target and destroy viruses in the blood.

As surgeons recognized the benefits of minimally invasive procedures, which dramatically reduce the risk of infection and widen the range of treatment techniques, they also became aware that they themselves were now a limiting factor. Even with the assistance of operating microscopes attached to laparoscopic tools, surgeons often couldn't move their hands precisely enough. Then in the 1990s researchers began to realize what had long seemed a futuristic dream—using computer-controlled robots to perform operations. Beginning in 1995 Seattle surgeon Frederic Moll, with the help of an electrical engineer named Robert Younge, developed one of the first robotic surgeon prototypes—a combination of sensors, actuators, and microprocessors that translated a surgeon's hand movements into more fine-tuned actions of robotic arms holding microinstruments. Since then other robotics-minded physicians and inventors have created machines that automate practically every step of such procedures as closed-chest heart surgery, with minimal human involvement.

The list of health care technologies that have benefited from engineering insights and accomplishments continues to grow. Indeed, at the end of the century bioengineering seemed poised to be fully integrated into biological and medical research. It seemed possible that advances in understanding the genetic underpinnings of life might ultimately lead to cures for huge numbers of diseases and inherited ills—either by reengineering the human body's own cells or genetically disabling invading organisms. Certainly engineering techniques—particularly computerized analyses—had already helped identify the complexities of the code. The next step, intervening by replacing or correcting or otherwise manipulating genes and their components, seemed in the offing. Although the promise has so far remained unfulfilled, engineering solutions will continue to play a vital role in many of medicine's next great achievements.