SPINA
Structure parameter inference approach for endocrine feedback control
SPINA is software for the rapid, reliable and accurate determination of constant structure parameters of endocrine feedback control systems. It is a class of static function tests that require nothing more than steady-state concentrations of hormones or metabolites obtained in vivo.
The first version of this cybernetic approach had been developed for the evaluation of the functional status of the thyroid gland, i.e. thyroid's secretory capacity (gain of thyroid, GT or SPINA-GT) and sum activity of peripheral deiodinases (GD or SPINA-GD).
A second version has been established for insulin-glucose homeostasis. It delivers the secretory capacity of pancreatic beta cells (SPINA-GBeta), an estimate for the insulin receptor amplification (SPINA-GR) and a static disposition index as a measure for the loop gain of the feedback loop (SPINA-DI).
Both implementations of SPINA have been validated in more than 50 clinical studies based on large cohorts.