Additive Manufacturing of Forceps With Continuous Carbon Fiber for Virtual Childbirth Training

Vaginal delivery assisted with forceps (FAVD) is an obstetric technique that involves the extraction of the fetus by traction and/or expansion of the birth canal with an instrument. Currently, the use of forceps allows for the resolution of pathological situations that would otherwise require a cesarean section with the risks of morbidity and mortality that this surgery entails. For this reason, there is a growing interest in increasing the percentage of FAVD, after obstetricians feel more confident after practicing in simulation workshops with mannequins and acquiring the necessary competencies for their correct use. The forceps is an instrument that requires a precise introduction and placement, so an electromagnetic tracking tool has been developed that knows, with high precision, the position of the instrument both inside the vagina and around the fetal head. With this, childbirth training is complemented by a virtual simulation, in real-time, that allows the internal position of the forceps to be seen, thus facilitating the learning and improvement of the introduction and placement technique. For this, the instrument must not contain any ferrous residue that interferes electromagnetically, so commercial forceps (made of stainless steel) are not valid. In this context, the reproduction of forceps has been proposed through additive manufacturing based on material extrusion (MEX). To obtain forceps that are as realistic as possible in terms of rigidity compared to commercial models, a nylon filament reinforced with carbon microfibers (Onyx) has been used to which continuous carbon fiber is added in successive layers. Given the limitations in the printing volume of the technology used (Mark Two), numerical simulations were carried out by finite element analysis and different proposals for dividing each piece and subsequent union by adhesives were made, finally developing the final solution. Keywords: additive manufacturing; carbon fiber extrusion; vaginal delivery forceps; medical training; electromagnetic tracking.