# A Workflow for Creating Gastric Computational Models from SPARC Scaffolds
## 4 Discussion
This provides evidence that the CM layer plays a more dominant role in the proximo-distal conduction of slow waves, likely due to its 3-5 times larger thickness compared to the LM layer. In practice, intramuscular ICC would play a role in the slow wave propagation, and a stomach model incorporating distributions and connections of intramuscular ICC could better reveal the coordinated roles of ICC and smooth muscle cells in the proximo-distal conduction of slow waves. In the simulations, an established ICC cell model [34] was used to represent slow waves, assuming a rapid and homogenous conduction to smooth muscle cells in the transmural direction. However, other cell models can be readily integrated into simulations [48; 49]. Future studies could employ smooth muscle cell models to model the electromechanical coupling in the rat stomach using fiber orientations and conductivity parameters informed by in vivo measurements of slow waves [32]. This would further impact the solution times based on the complexity of cell models. Moreover, adding a mechanical component to simulations will further increase the computational complexity [11; 12; 40]. In addition to solution times, different FEM models might result in noticeable differences in other organ functions that were not simulated in this study, such as mechanical contractions, which would involve other considerations, including restriction of contraction due to intragastric pressure, ligamentous or connective tissue connections to the stomach, and limitations on movements imposed by adjacent organs. It has been previously reported that contractions of the CM layer contributed to the intraluminal pressure more than the contractions of the LM layer [50]. Therefore, it is possible that the structural differences in the LM and CM layers of the two 3D FEM models could result in differences in mechanical patterns. Therefore, it is important to comprehensively assess the function of interest to select the most appropriate FEM model in simulations and to incorporate other features of the stomach and its environment. The FEM models were created using selected software packages that are capable of generating surface (i.e., triangular) and volume (i.e., tetrahedral) meshes. Stomach FEM models could also be generated using other software packages with equivalent capabilities, and the impact of software selection was not investigated in this study. While using different software packages might affect the resultant mesh characteristics and simulation performance (i.e., solution time), we do not expect to see impact on the structural characteristics in the FEM models and spatiotemporal outcome of the simulations, as they were informed by experimental measures. This is supported by the similar propagation profiles observed across the three FEM models we constructed. However, increasing simulation performance would be very useful to allow the 3D FEM models to be used in longer simulations to study organ functions more accurately. In future, a systematic evaluation to identify the optimal toolboxes and associated constraint parameters could be beneficial. A specific limitation for the current application to the stomach is that the SPARC scaffold is based on a stylized gastric anatomy, and certain regions such as the pylorus, esophago-gastric junction, and fundus do not accurately represent the in-vivo gastric anatomy in rats. Additionally, the inner (oblique) muscle layer and the esophago-pyloric ligaments have not been incorporated into the FEM models, because it is uncertain whether they generate or conduct slow waves, and our current focus is on modelling bioelectrical activity in the stomach. Therefore, their exclusion from the computational models would likely not impact the slow wave simulations. However, the oblique muscle layer and the ligaments contribute to movements at the lesser curvature, which will need to be incorporated for biomechanical simulations.