Each new medical device invigorates public debate on ethical issues. What are the costs and who is likely to benefit? On whom or what should it be tested? How are patients and their families informed about the experimental procedure and its consequences? Who sets guidelines at the cutting edge of medicine? And—ultimately—what makes or keeps us human?

Changing Technology

For most of human history, medical devices have been limited to splints and braces worn on the surface of the body. Orthotics (devices which support or correct the function of a limb or the torso) are still in use today. But things have become more complicated recently with the possibility of electrical and computerized mechanisms and synthetic materials. Do implantable devices have a greater potential for altering the nature of human beings?

In the 1960s and 1970s, when researchers began to understand the human body’s response to foreign materials, the number and variety of implantable devices exploded. As science and engineering advanced, government agencies and the public, especially religious groups, scrambled to comprehend this new and unfamiliar landscape of medical technology.

Meet Yorick

This plastic skeleton, resplendent with artificial devices, is a snapshot in three dimensions of late-20th-century medicine. The Food and Drug Administration (FDA) engineers who began to assemble the figure in the 1970s nicknamed it Yorick (after the jester’s skull encountered by Shakespeare’s Hamlet). The figure contains working hardware sent to the FDA for safety testing over the last three decades.

In a Heartbeat

AbioCor Total Artificial Heart is the first electro-hydraulic artificial heart implanted in a human. Approved by the U.S. Food and Drug Administration for clinical trials, the AbioCor was implanted in Robert Tools on July 2, 2001, at Jewish Hospital in Louisville, Kentucky. The historic operation marked the first time an artificial heart had been used as a permanent replacement for a human heart since the air-powered Jarvik-7 artificial heart was implanted almost two decades earlier.

AbioCor Total Artificial Heart Learn more		Robert Tools, first patient to receive an AbioCor. Learn more

Immune Response and Tissue Rejection

The human body, made of living tissue, responds to changes in its environment, whether external or internal. An artificial limb pressing against the skin’s surface, an artificial eye sutured into an empty socket, or the shaft of a metal hip cemented to the top of the femur—all cause the body to react. Full-scale rejection of materials can cause death. Rejection was the main hurdle to development of successful implantable devices.

One solution to the problem of rejection was to give the patient drugs to dampen the immune system, but this caused other serious problems. In the 1960s and 1970s, researchers focused their efforts on finding inert (or biocompatible) materials for the devices that went into the body. Their goal was to thwart rejection by matching the body’s own tissue as closely as possible. In the 1980s, researchers changed strategies and worked on bioactive materials that would create a reaction but in a positive direction. For example, bioactive materials encouraged bonding with bone or were absorbed once an incision mended.

In the 1990s, success with bioactive ceramics, biodegradable sutures, and other materials generated interest in restorative healing and tissue engineering. In tissue engineering, the replacement material is tissue grown outside the body and implanted, or tissue within the body that is jump-started with growth factors or other gene-activating materials. Physicians use biomaterials to stimulate cells to proliferate and differentiate into the kind of tissue needed (such as skin, cartilage, bone). Artificial skin is an example of bioengineered tissue.

1976 Medical Devices Act

In the late 1960s, on the heels of the blossoming medical-device industry and highly publicized court cases that exposed problems with pacemakers, the U.S. Congress began hearings on how to ensure the safety of new kinds of medical devices. At the time, the only regulated medical devices were those classified as drugs. The 1970 Cooper Report, requested by the secretary of the Department of Health, Education and Welfare, summarized the issues involved and laid out a legislative plan for establishing standards and procedures for review.

The 1976 Medical Device Amendments to the Federal Food, Drug and Cosmetic Act (of 1938) brought instruments, machines, and implants under the oversight of the Food and Drug Administration. Everything from contact lenses and Band-Aids to artificial hearts and lasers for surgery would now have to be proven safe and effective before being released to consumers.