Fetus-supporting flexible manipulator with balloon-type stabilizer for endoscopic intrauterine surgery.

BACKGROUND Minimally invasive endoscopic fetal surgery enables intrauterine intervention with reduced risk to the mother and fetus. A novel surgical manipulator is described for stabilizing the fetus and restraining it from floating free during endoscopic intrauterine surgery. METHODS We designed and fabricated a prototype fetus-supporting manipulator equipped with flexible joint and bending mechanisms and a soft balloon stabilizer. The flexible joint and bending mechanisms enable the stabilizer to reach the target sites within the confined space of the uterus under the guidance of an ultrasound device. The balloon stabilizer could be inserted into the uterus through a small incision. RESULTS The accuracy evaluation showed that the maximum error of the bending mechanism was as small as 7 mm and the standard deviation of the joint mechanism was just 1.6 degrees. In the experiments using a fetus model, the manipulator could be well controlled with guidance from ultrasound images and its bending mechanism with the balloon stabilizer could be clearly visualized while stabilizing the fetus model. CONCLUSIONS The manipulator has the potential to be used in minimally invasive intrauterine surgery, although further improvements and experiments remain to be carried out.