Implantable Artificial Hearts

The implantable artificial heart is a device that many have hoped to produce and use to replace a defective natural heart. The first implantable artificial heart was developed by Domingo Liotta and was implanted by surgeon Denton Cooley in Texas, in 1969. The artificial heart was used for 64 hours by the patient, Haskell Karp, for 64 hours before a transplant heart became available. Although Karp died shortly after the transplant of the natural heart, the artificial heart proved to be viable as a bridge to a transplant heart.
Later, the Jarvik 7 Artificial heart was developed by Dr. Robert Jarvik and was first implanted into a patient in 1982. The Jarvik heart was designed to mimic the natural heart, with two pumps. The longest surviving patient with a permanent Jarvik implantation was William Schroeder, who had the Jarvik heart for 620 days before death. The pumps are air-driven by an external refrigerator-sized box that contains compressed air tanks and vacuum equipment, although there are internal tanks for use during an emergency. While no permanent Jarvik-7 patient survived more than a half-year, the device continues to be used as a bridge unit in selected hospitals.
One of the newest types of the implantable artificial heart is called the AbioCor. It is completely self-contained, with no external device or wires piercing the skin needed. It contains a two-pound pumping unit that contains artificial ventricles that operate using pressure gradients created by the 8000 rpm pump. There is a 20-minute emergency internal battery pack that is used in case of failure of the external, belt-worn battery pack. The battery and power system are able to transmit the power transcutaneously, through the skin, wirelessly. The AbioCor is a major breakthrough in artificial heart development because it will allow for patient mobility without a large external pump.
Sources:
http://en.wikipedia.org/wiki/Artificial_heart
http://texasheart.org/Research/Devices/abiocor.cfm
http://americanhistory.si.edu/exhibitions/small_exhibition.cfm?key=1267&exkey=143&pagekey=216