Vision Based Robot Assistance in TTTS Fetal Surgery

Robot assisted Fetoscopic Laser Coagulation: Improvements in navigation, re-location and coagulation

Fetoscopic Laser Coagulation (FLC) for Twin to Twin Transfusion Syndrome is a challenging intervention due to the working conditions: low quality images acquired from a 3 mm fetoscope inside a turbid liquid environment, local view of the placental surface, unstable surgical field and delicate tissue layers. FLC is based on locating, coagulating and reviewing anastomoses over the placenta's surface. The procedure demands the surgeons to generate a mental map of the placenta with the distribution of the anastomoses, maintaining, at the same time, precision in coagulation and protecting the placenta and amniotic sac from potential damages. This paper describes a teleoperated platform with a cognitive-based control that provides assistance to improve patient safety and surgery performance during fetoscope navigation, target re-location and coagulation processes. A comparative study between manual and teleoperated operation, executed in dry laboratory conditions, analyzes basic fetoscopic skills: fetoscope navigation and laser coagulation. Two exercises are proposed: first, fetoscope guidance and precise coagulation. Second, a resolved placenta (all anastomoses are indicated) to evaluate navigation, re-location and coagulation. The results are analyzed in terms of economy of movement, execution time, coagulation accuracy, amount of coagulated placental surface and risk of placenta puncture. In addition, new metrics, based on navigation and coagulation maps evaluate robotic performance. The results validate the developed platform, showing noticeable improvements in all the metrics.