Assessment of a Hexapod Surgical System for Robotic Micro-Macro Manipulations in Ocular Surgery

Purpose: Robotic intraocular microsurgery requires a remote center of motion (RCM) at the site of ocular penetration. We designed and tested the Hexapod Surgical System (HSS), a microrobot mounted on the da Vinci macrorobot for intraocular microsurgery. Material and Methods: Translations and rotations of the HSS were tested for range of motion and stability. Precision and dexterity were assessed by pointing and inserting a coupled probe into holes of various sizes. The stability of a nonmechanical RCM was quantified. HSS functionalities were observed on porcine eyes. Results: The HSS maximal translations were 10 (x and y axes) and 5 cm (z axis). The maximal rotations were 15 and 22° (x and y axes). The precision was within 0.5 mm away from targets in 26/30 tests and maximal in 16/30 tests. The mean translational and rotational stability at the tip of the probe were 1.2 (0.6–1.9) and 1 mm (0–2), respectively. The average dexterity times were 5.2 (4.4–6.5), 7.1 (5.6–10.8) and 12.3 s (7.8–21.7) for 5-, 2- and 1-mm holes, respectively. The RCM was stable (within 0.1 mm). A vitreous cutter coupled to the HSS moved into porcine eyes through a sclerotomy with a stable RCM. Conclusion: The HSS provides an RCM dedicated for intraocular robotic surgery with a high level of precision and dexterity. Although it can be further improved, the micro-macro robotic system is a feasible approach for ocular surgery.