Palo Alto, Calif. - Peer Portner, the inventor of an implanted electrical pump for heart-failure patients, has died. He was 68.

Portner died Monday of cancer at his home in the San Francisco Bay area, according to a statement from Stanford University.

Originally trained as a nuclear physicist, Portner became a consulting professor of cardiothoracic surgery at Stanford University School of Medicine. He began working with doctors at the school in the early 1970s to develop his pump, called the left ventricular assist device.

In 1984, the device kept a heart patient alive for eight days until a heart transplant was found, the first time such a device was successfully implanted in a human, the university said.

Portner founded Novacor Medical Corp. to develop the pump and led research for more than 30 years to improve the device.

More than 1,700 patients in more than 100 medical centers around the world have had the device implanted.