"Cyborg" is a science-fictional shorting of "cybernetic organism". The idea is that, in the near future, we may have more and more artificial body parts - arms, legs, hearts, eyes - and digital computing and communication supplements. The logical conclusion is that one might become a brain in a wholly artificial body. And the step after that is to replace your meat brain by a cyberbrain.

References

Technology as Extension of Human Functional Architecture

An essay about technological extensions to human - attachments, implants, wrappers, manipulators...

Presenting the Cyborg's Futurist Past : an Analysis of Dziga Vertov's Kino-Eye

Cyborg Anthropology Archive

An archive by Electronic Frontier Foundation.

Manifeste Cyborg

Science, technologie et féminisme socialiste à la fin du 20e siècle, par Donna Haraway.