Manfred E. Clynes; Nathan S. Kline (September 1960), Cyborgs and space, in Astronautics[1]:

For the exogenously extended organizational complex functioning as an integrated homeostatic system unconsciously, we propose the term Cyborg. The Cyborg deliberately incorporates exogenous components extending the self-regulatory control function of the organism in order to adapt it to new environments. [] The purpose of the Cyborg, as well as his own homeostatic systems, is to provide an organizational system in which such robot-like problems are taken care of automatically and unconsciously, leaving man free to explore, to create, to think, and to feel.

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cyborg – Wiktionary