Background: The global overuse of Caesarean sections (C-sections), especially in high-resource settings, and the underuse of assisted vaginal deliveries in low-resource regions highlight the need for improved Vacuum-Assisted Delivery (VAD) training tools. Existing phantoms, such as "Lucy and Lucy’s Mum," suffer from anatomical inaccuracies and limited biomechanical realism, restricting their effectiveness. This project aimed to design a new, cost-effective VAD training phantom that addresses these limitations by providing more accurate anatomical structures and biomechanical responses.

Design and Manufacturing: The final phantom design utilised Polylactic Acid (PLA) and FDM 3D printing techniques for solid parts and Ecoflex™ 00-30 silicone reinforced with 20 Denier nylon fabric for simulating the pelvic floor muscles and their biomechanical behavior during childbirth. The fetal head was constructed using PlatSil® Gel-25 silicone for the inner deformation core, and Ecoflex™ 00-30 reinforced with 80 Denier nylon fabric for realistic scalp deformation. Additionally, the phantom's modular design and aluminum-made supporting frame allowed easy replacement of parts for long-term use and more flexible phantom deployment.

Validation Results: Two validation phases were conducted. In the first phase, 5 gynecologists provided feedback, identifying issues with vacuum cup application and some biomechanical behaviors. These issues were fully addressed in the final design. The final validation, conducted by one single expert, confirmed that the vacuum cup application issue had been resolved. However, a new issue related to the palpation of the ischial spine was identified. Quantitative testing measured traction forces and pulling angles during VAD, confirming that the phantom accurately replicated clinical behaviors. The overall performance was highly rated.

Conclusion: This newly developed VAD training phantom mostly overcomes the critical limitations of existing models by enhancing both anatomical accuracy and biomechanical realism. The modular and cost-effective design ensures flexibility and allows for use in a wide range of obstetric training settings. However, the cost per training has yet to be fully evaluated, and further research is needed in this regard. Both qualitative expert feedback and quantitative testing confirmed the phantom’s effectiveness in improving VAD training. While the palpation issue identified in the final validation remains to be addressed, the lack of comprehensive data on specific anatomical and biomechanical properties continues to hinder the development of even more accurate models.