Purpose To improve the time efficiency of current vitreoretinal surgical procedures and to enable new procedures demanding improved accuracy, a robotic system has been developed, extending human capabilities beyond current limits. A combination of advanced mechanical and control design facilitates high accuracy, tremor filtering, automated instrument changing and an ergonomic body posture for the surgeon. Setting A compact, lightweight and easy to set up robotic master-slave system is realized to assist in vitreoretinal surgery. This demonstrator can reach all major areas within the vitreous cavity, including the periphery. For the first tests, vision is obtained by HD-video to a 24" monitor, with a magnification of 20-times. Methods The accuracy and reproducibility of the system are validated via bench experiments, including pointing and pick-and-place tasks. The tasks include pinching holes at pre-defined points on paper, such as the intersections of veins on a retina printed on paper and using mm-squared paper. Functionality of the system for vitreoretinal surgical procedures is validated via ex-vivo experiments, using a synthetic eye model, the chorioallantoic membrane (CAM) of chicken eggs and porcine eyes. The experiments include cannula placement, vitrectomy and membrane peeling. Results First functional tests with the demonstrator system show a short setup time of less than 2 minutes, an intuitive usage in combination with good ergonomics and satisfactory instrument reach and accuracy. The system has an intrinsic accuracy of 5µm. Pointing tasks show accuracy down to 38µm ±28µm, which is restricted by the current video system. User tremor is effectively filtered and a motion scaling of 20 to 40 times is considered comfortable. The intuitive usage results in a short learning curve; users adapt in minutes and are able to perform surgical tasks successfully within an hour of first usage. With a knife and a pick, a successful peel of the inner shell membrane of the CAM of a chicken egg was made on the first attempt. The peel was performed within 2 minutes and without any complications such as bleeding Conclusions A microrobotic surgical system for vitreoretinal surgery was created that meets the requirements and constraints imposed by this type of specialized surgery. The first functional tests indicate that these requirements and constraints were met using a demonstrator system. It promises to improve current vitreoretinal surgical procedures in time efficiency and accuracy, and enable new, high-precision procedures. Financial disclosure This research was financially supported by the IOP Precision Technology program of the Dutch Ministry of Economic Affairs.
|Title of host publication||Abstract presented at the 12th EURETINA Congress, 6-9 September, Milan|
|Publication status||Published - 2012|