A high-water retention, self-healing hydrogel thyroid model for surgical training

The evaluation of thyroid lesions through Fine-Needle Aspiration Biopsy (FNAB) is a common procedure that requires advanced hand manipulation skills. Conventional training models for this procedure lack essential features such as tactile sensation and the ability to repeat punctures similar to those of real organs. To improve the quality of training, we have developed a hydrogel thyroid model that possesses features such as high-water retention and self-healing properties. This model consists of polyvinyl alcohol (PVA), polyacrylic acid (PAA), and trehalose that enhance water retention. By utilizing indirect printing technology, this hydrogel-based thyroid model closely resembles those of porcine thyroid tissue in terms of compression modulus and friction coefficient, exhibiting exceptional conformability, flexibility, and a water retention rate of 94.7 % at 6 h. It also displays a thrust force range of 0-0.98 N during simulated puncture, closely approximating real FNAB operations. This model shows evidence that it effectively simulates thyroid tissue and can be utilized for repetitive FNAB training to enhance the proficiency of medical personnel. Our study focuses on introducing new possibilities for developing advanced materials training models to be utilized in the medical field.