Design and additive manufacturing by FDM, feasibility and reproducibility of a anthropomorphic-heterogeneous silicone/TPU/ABS mannequin for CT image analysis: a proof-of-concept study

Abstract Anthropomorphic mannequins are widely used in biomedical research, medical imaging studies, and clinical training. However, commercial models are often expensive and have limitations in terms of anatomical customization. This study evaluates the feasibility and reproducibility of manufacturing a heterogeneous anthropomorphic mannequin using various polymeric materials via additive manufacturing with fused deposition modeling (FDM) technology. The size and shape are based on specific biometric measurements to emulate clinical situations. The mannequin is designed in three layers, and different 3D printing materials were selected for each tissue: silicone ink (skin), thermoplastic polyurethane (TPU, muscle), and acrylonitrile butadiene styrene (ABS, cortical and trabecular tissue). The novel aspect of this mannequin is the design of the trabecular structure, obtained from a mathematical model. Furthermore, a novel manufacturing methodology for the heterogeneous anthropomorphic structure of skeletal mannequins is presented. Morphological characterization from computed tomography (CT) images was used to evaluate the FDM manufacturing process and the resulting internal structures. Quantitative and qualitative analyses, including fractal dimension analysis and Hounsfield Unit (HU) measurements, were performed to assess the consistency of geometric complexity and the radiological response of the selected materials. The statistical analysis using a linear mixed-effects model (LMM) evaluated differences in fractal dimension among independently manufactured phantoms while accounting for the correlation among tomographic slices obtained from the same phantom. HU measurements provided a quantitative comparison between the selected materials and the corresponding human tissues. These results demonstrate the potential of FDM technology as an accessible alternative for manufacturing anatomical mannequins used in research and medical simulation applications.