A mechanical contact model for the simulation of obstetric forceps delivery in a virtual/augmented environment

During the process of human childbirth, obstetric forceps delivery can be a justified alternative to emergency Caesarean section when normal vaginal delivery proves difficult or impossible. Currently, training of forceps interventions is mainly done on real patients which poses a risk. This paper describes a pilot project on the simulation of training of obstetric forceps delivery, using Virtual Reality technology. We first give a brief historical review of the concept of 'birth simulation' and describe the current implementation of the interface. Then we report a number of experiments, conducted to test the feasibility of a real-time mechanical contact model to describe the interaction between the forceps and fetal head, eventually to be interfaced with a multi-purpose haptic feedback device. It is concluded that an explicit dynamic model to calculate the deformation of the main fetal skull bones only, or a quasi-static model to calculate the deformation of the fetal head in its entirety, can reach real-time performance.