During the early
1980s American physician William DeVries
implanted the Jarvik-7 artificial
heart
into several patients. Although one patient with an
implanted Jarvik-7
survived 620 days, this artificial heart caused many serious medical
complications. Presently, artificial hearts are used only on a temporary basis
until a human heart becomes available.
One way to get around the shortage of donors is to use
wholly or partially artificial organs made of plastic, metal, and other synthetic
materials. A kidney dialysis machine, for example, is an artificial organ, even
if it is too large to implant in the body. In 1982 American physician William
DeVries implanted a crude artificial heart into the chest of dentist Barney
Clark. But Clark survived for only 112 days and the heart itself, powered by an
air pump that required its own cart, proved impractical. Although subsequent
researchers have built smaller, more efficient hearts, none of these
devices have proved successful. Instead, emphasis has shifted to the use of
left-ventricular assist devices (LVADs), which are implanted beside a patient’s
heart to help it pump blood. LVADs keep patients alive until a donor heart is
available. Many artificial devices work to restore the operation of
malfunctioning organs without replacing the whole organ. Examples include
artificial heart valves and pacemakers to help the heart function properly, and
cochlear implants to restore hearing.