Dual-concentration PVA hydrogel brain phantom for neurosurgical training

Abstract

Neurosurgical training demands realistic tissue phantoms that replicate mechanical and imaging properties of human brain tissue. This work presents a polyvinyl alcohol (PVA)-based phantom simulating healthy and pathological brain tissue by exploiting the material properties of different PVA concentrations. The phantom enables a training system that offers accurate mechanical behavior and ultrasound visualization. A three-part casting system was developed using 3D-printed Acrylonitrile Butadiene Styrene (ABS) molds to produce brain phantoms with an insertable tumor component. Two PVA formulations were prepared: 10% concentration representing healthy brain tissue and 15% concentration simulating pathological tissue. After one freeze-thaw cycle, the specimen underwent mechanical characterization according to ISO 7743:2017-10 and an ultrasonic evaluation using clinical imaging equipment. Compression testing revealed distinct mechanical behavior between PVA concentrations. At 25% strain, 15% PVA exhibited stress values of 1.92 ± 0.08 kPa while 10% PVA demonstrated 1.25 ± 0.03 kPa, mimicking the reported mechanical properties of brain tissue [1,2]. Ultrasound examination showed material differentiation with boundary artifacts in between layers. Dimensional analysis of the ultrasound images demonstrated great accuracy with the original design. Clinically relevant mechanical differences between simulated tissue types were successfully created using the multi-concentration approach. The system provides anatomically accurate phantoms suitable for neurosurgical education and ultrasound imaging, representing significant advancement in tissue-mimicking technology for medical training applications.