Fig. 3.

The SIMPA file data structure is hierarchical. The output file of SIMPA uses the Hierarchical Data Format 5 (HDF5). The top-level fields are (1) Settings in which the input parameters for the global simulation pipeline as well as for all pipeline elements are stored in. (2) The Device describes the digital device twin with which the simulations are performed. (3) The Simulations field stores all of the simulation property maps that serve as input for the pipeline elements, such as the optical absorption (${\mu }_a$), scattering (${\mu }_a$), and anisotropy ($g$). These properties are wavelength-dependent and therefore are saved for each wavelength respectively. The density ($\rho$), acoustic attenuation ($\alpha$), speed of sound ($\nu$), Grüneisen parameter ($\mathrm{\Gamma }$) or blood oxygen saturation (${\mathrm{sO}}_2$) are wavelength-independent and therefore only stored once. The Simulations field also stores the outputs for each wavelength of each processing component and simulation module such as optical fluence ($\varphi$), initial pressure ($p_0$), time series pressure data ($p(t)$), or the reconstructed image ($p_0^{\mathrm{recon}}$). (4) The simulation pipeline is a list that stores the specific module adapters that have been combined and their order to form the simulation pipeline.