3D printed phantom to mimic dynamic softening of cervix during pre-labour

It is thought that through the development of more realistic training models for midwives and obstetricians it may be possible to reduce the overuse of labour induction. To this end we demonstrate a method for creating pneumatically-controlled phantom cervixes using thermoplastic elastomer, filled with a granular material. The maximum spring constant of the phantom cervix was measured to be 10.5 N/m at -20 kPa deflated air (vacuum) and the minimum spring constant measured was 5.3 N/m at 20 kPa inflated air. The true stress measured on these elastomeric phantom cervixes indicated a maximum stress of 133 kPa and a minimum stress of 94 kPa at 0.15 strain. Discrimination and threshold tests demonstrated that people can distinguish between the hard and soft states of the phantom. Future work will focus on increasing the softness of these devices.