In [this article about human physiology as a complex network][1] the authors say that: > "Lacking adequate analytic tools and a theoretical framework to probe > interactions within and among diverse physiological systems, current > approaches focus on inferring properties of time-varying > interactions—namely strength, direction, and functional form—from > time-locked recordings of physiological observables." and further: > The characterization of interactions between physiological systems > faces several challenges: > > • We often do not know exactly the systems’ > equations of motion; > > • We lack knowledge as to how to merge/combine > these equations (e.g., due to the issue of time-scale matching); > > • We may have insufficient knowledge about relevant structural connections; > • We may not have direct access to interactions between systems (e.g., > via probing). Image taken from the above article, where each node corresponds to a human organ and connections between organs represent time varying "connections": [![Image taken from the above article, where each node corresponds to a human organ and connections between organs represent time varying "connections"][2]][2] Are there tools of complex networks from mathematical point of view which might be suited for the case written above? [1]: https://www.frontiersin.org/articles/10.3389/fphys.2020.598694/full [2]: https://i.sstatic.net/5Brxx.jpg