We will assembly and quantitatively assess previously independent mathematical models of (a) zero-dimensional system cardio-pulmonary physiology and (b) CNS / ANS regulation. We will identify mergent modalities of coupled models. The aim is to develop coupling of mathematical models in benchmark structure. First, coupled low order models will be enhanced and rationalised, reconciled and compared to form an initial, interchangeable set of computational tools, capable to adress regulation problems. Regulation models and mechanical models will then be coupled. Sensitivity and uncertainty analysis will be performed to reveal parametric interractions and model space, which assist in placing them into the appropriate regime of operation limited by physiological boundaries. Appropriate mechanisms to present results to clinical end-users will be developed and assessed at this stage. Coupled models will be applied to either clinical data sourced from the literature, or to existing data on hypovolemia, as appropriate.