Optical and Mechanical Optimization of 3D-Printed Anatomical Models for Medical Education

Anatomical 3D printing holds significant promise in medical education by enabling the creation of anatomically accurate and mechanically realistic models. While tissue-mimicking materials (TMMs) provide haptic feedback for procedural training, their utility is limited by poor optical clarity. This lack of transparency restricts visualization of internal anatomy and tool movement, particularly in procedures like percutaneous coronary intervention (PCI), where spatial awareness is critical. This study aimed to improve the optical clarity of flexible, elastomeric 3D-printed anatomical models without compromising mechanical realism. This study evaluated dip coating of conformal silicone (S C ), conformal acrylic (A C ), conformal polyurethane (P C ), oil-based polyurethane (P O ), and water-based polyurethane (P W ) for their ability to enhance transparency and preserve the mechanical properties of the Stratasys PolyJet material Agilus30Clear. All coatings significantly reduced absorbance at 600 nm, with S C , A C and P C delivering the greatest optical improvements of up to 91%. S C and P C best preserved mechanical behavior, remaining within 20% in stiffness and strain at failure, whereas A C , P O , and P W caused significant stiffening and reduced strain to failure. Constitutive nonlinear elastic models including neo-Hookean, Ogden and Holmes-Mow with perfect plasticity were fit to tensile data to facilitate target tissue matching, while comparing strategies for reporting representative properties. Using a transparent left main coronary artery (LMCA) model, we demonstrated real-time guidewire navigation under direct visualization, highlighting the educational utility of the model. These findings have implications beyond medical education, with potential applications in patient-specific surgical planning, preclinical device testing, and reducing reliance on cadavers and fluoroscopy.