Engineering a High-Fidelity Neonatal Silicone Phantom: Development, Optimization, and User Evaluation of a 3D-Printed Vascular Access Model

Securing intravenous (IV) access in neonates is technically challenging due to extremely small vessel caliber, fragile skin, and limited subcutaneous tissue. High-fidelity training phantoms are essential for teaching ultrasound-guided vascular access, yet most commercial models are adult-sized, lack neonatal realism, and are cost-prohibitive. The aim of this study was to design and optimize a low-cost, ultrasound-compatible 3D silicone phantom that replicates neonatal tissue and vasculature for peripheral and central IV access training. A multi-phase design process incorporated 3D-printed polylactic acid (PLA) molds, Dragon Skin™ silicone (Smooth-On, Inc., Macungie, PA, USA), Slacker® softener (Smooth-On, Inc., Macungie, PA, USA), and 3% talcum powder to enhance echogenicity. Silicone tubing (0.2-0.4 mm internal diameters (ID)) was embedded at neonatal-appropriate depths using rotational casting for dermal uniformity and vessel channel supports for positional accuracy. Iterative engineering improved dermal wall uniformity, vessel stability, and ultrasound visibility, resulting in a durable, reproducible phantom with realistic tissue compliance and vessel compressibility. The developed 3D silicone phantom provides a realistic, affordable, and reproducible neonatal vascular access simulator. User feedback supports its fidelity and utility, and its low material cost enables broad implementation in neonatal procedural training programs.