Freeform fabrication of tissue-simulating phantoms by combining three-dimensional printing and casting

摘要

Appropriate surgical planning is important for improved clinical outcome and minimal complications in many surgical operations. In order to provide an intuitive model for better surgical planning, we develop a novel process that combines 3D printing and casting for freeform fabrication of tissue-simulating phantoms. 3D computer models of biological systems including body and internal organs are sliced, processed, and converted into data format suitable for Fused Deposition Modeling (FDM). The hard tissue structures, such as bones and skeletons, are printed directly by FDM using Acrylonitrile-Butadiene-Styrene (ABS) material. The soft tissue structures, such as soft internal organs, are fabricated by casting silicon materials of different compositions in FDM printed shell molds. Contrast agents of different compositions are added in the silicon materials to mimic different tissue contrasts in computed tomography (CT).The hard and the soft tissue structures are then assembled by fixture joints to maintain their positional fidelity. The assembly is then placed within a FDM printed shell mold of the body for further casting. The produced tissue-simulating phantoms are CT scanned and compared with that of the original computer models in order to verify the structural and positional fidelity. Our preliminary experiments showed that combining FDM with casting is an effective approach to produce solid phantoms with geometric and positional fidelities for potential surgical planning applications in many clinical interventions.