Development and Comparative Evaluation of Low-Cost Ultrasound-Guided Regional Anesthesia Phantom Models

Regional anesthesia is vital for modern surgical practices, but accessibility to training is often hampered by the high cost of commercial phantom models. This study aimed to develop and evaluate low-cost, realistic phantom alternatives using Ecoflex, borax-containing polyvinyl alcohol (PVA), and plastisol compositions. The models were evaluated under ultrasound for imaging properties, including needle visibility, tissue resistance, cost, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), axial full width at half maximum (FWHM), and compared to a commercial reference (Blue Phantom). Initial qualitative assessments were performed by three experienced evaluators, and inter-observer agreement demonstrated good to excellent reliability. In addition, a long-term usability assessment was conducted more than one year after phantom preparation, involving 20 participants using a structured Likert scale. A statistically significant difference was observed among materials (Friedman test, p < 0.05), with PVA hydrogel containing 20 g borax and the Blue Phantom demonstrating the highest tissue realism scores, without a significant difference between them. The results showed that plastisol softener and PVA (20 g borax) hydrogel provided excellent needle visibility and tissue resistance and achieved an imaging performance comparable to the commercial model. Notably, CNR and SNR values for these materials approached reference levels, while costs ranged from $0.5 to $2.50 per 100 mL, representing a significant reduction compared to $45 per 100 mL for commercial models. In conclusion, this research confirms that affordable materials such as PVA and plastisol can effectively simulate human tissue for ultrasound-guided training. Furthermore, the findings suggest that PVA-based hydrogels may provide sustained usability over time, offering a practical and accessible solution for enhancing clinical skill acquisition in resource-constrained settings.