Balloon-based manipulator with multiple linkages for intrauterine surgery

This paper describes a manipulator for controlling position and posture of fetus in uterus and a surgical procedure for supporting the fetus in intrauterine surgery. The manipulator is equipped with multiple linkages and a balloon to support the fetus softly in the uterus. The linkages with two bending mechanisms are designed for inserting the balloon to an optimal position under the fetus. The balloon is fold before the operation and inflated by saline water after arriving at the required position in the uterus. Accuracy evaluation showed that the standard deviations of the bending angle of the wire-driven mechanism and the linkages-driven mechanism were 1.0 degree and 2.5 degree, respectively. Force experiment showed that the balloon-type stabilizer could generate load-bearing power of 500 gf. Furthermore, the manipulator could be well controlled with guidance of ultrasound images. The manipulator could minimize injure to the fetus since the area contacted with the fetus by the balloon could be well controlled.