''Heterostasis'' is a medical term. It is a

neologism A neologism Greek νέο- ''néo''(="new") and λόγος /''lógos'' meaning "speech, utterance"] is a relatively recent or isolated term, word, or phrase that may be in the process of entering common use, but that has not been fully accepted int ...

coined by

Walter Cannon Walter Bradford Cannon (October 19, 1871 – October 1, 1945) was an American physiologist, professor and chairman of the Department of Physiology at Harvard Medical School. He coined the term " fight or flight response", and developed the theor ...

intended to connote an alternative but related meaning to its lexical sibling

Homeostasis In biology, homeostasis (British English, British also homoeostasis) Help:IPA/English, (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physics, physical, and chemistry, chemical conditions maintained by organism, living systems. Thi ...

, which means 'same state'. Any device, organ, system or organism capable of Heterostasis (multistable behavior) can be represented by an abstract

state machine A finite-state machine (FSM) or finite-state automaton (FSA, plural: ''automata''), finite automaton, or simply a state machine, is a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number o ...

composed of a characteristic set of related, interconnected states, linked dynamically by change processes allowing transition between states. Although the term 'Heterostasis' is an obvious rearrangement (by syntactically substituting the prefix 'Hetero-' for its dichotome 'Homeo-', and likewise swapping the semantic reference, from 'same'/'single' to 'different'/'many'), the endocrinologist

Hans Selye János Hugo Bruno "Hans" Selye (; hu, Selye János; January 26, 1907 – October 16, 1982) was a pioneering Hungarian-Canadian endocrinologist who conducted important scientific work on the hypothetical non-specific response of an organism to s ...

is generally credited with its invention. An excellent overview of the two concepts is contained in the Cambridge Handbook of Psychophysiology, Chapter 19. Selye's ideas were used by Gunther et al.,Gunther, B., Morgado, E., Jimenez, R.F. (2003
Homeostasis to Heterostasis: from invariant to dimensionless numbers
Biol. Res. 2003;36(2):211-221 in which dimensionless numbers (allometric invariance analysis) were used to investigate the existence of heterostasis in canine cardiovascular systems.

Alternative terminology

The equivalent term

Allostasis Allostasis also known as “body budgeting” which Lisa Feldman Barret argues, proposes that efficient regulation requires preparing the body to satisfy the needs before they arise by budgeting those needed resources such as oxygen, insulin ...

is used in biological contexts, where state change is analog (continuous), but Heterostasis is sometimes preferred for systems which possess a finite number of distinct (discrete) internal states, such as those containing computational processes. The term

Servomechanism In control engineering a servomechanism, usually shortened to servo, is an automatic device that uses error-sensing negative feedback to correct the action of a mechanism. On displacement-controlled applications, it usually includes a built-in e ...

is usually used in industrial/mechanical situations (non-biological and non-computational) where it often applies to analog state change, e.g. in a Direct Current

Servomotor A servomotor (or servo motor) is a rotary actuator or linear actuator that allows for precise control of angular or linear position, velocity and acceleration. It consists of a suitable motor coupled to a sensor for position feedback. It also ...

References

{{Reflist Homeostasis Servomechanisms Technology neologisms