The jacobian class is derived from [1]. And the artery tree model can be found in [2].
[1] Hesthaven, Jan S., and Tim Warburton. Nodal discontinuous Galerkin methods: algorithms, analysis, and applications. Springer Science & Business Media, 2007.
[2] Olufsen, Mette Sofie. Modeling the arterial system with reference to an anestesia simulator. Diss. Roskilde Universitetscenter, Institut for Studiet af Matematik og Fysik samt deres Funktioner i Undervisning, Forskning og Anvendelser, 1998.