Assessment of a hexapod surgical system for robotic micro-macro manipulations in ocular surgery.
OBJECTIVE
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.


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.


CONCLUSIONS
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.
Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, CA, USA. jean-louis.bourges@htd.aphp.fr
Jean-Louis
JL
Bourges
Jean-Pierre
JP
Hubschman
Jason
J
Wilson
Stephen
S
Prince
Tsu-Chin
TC
Tsao
Steven
S
Schwartz
D000818:Animals; D001696:Biomechanical Phenomena; D004867:Equipment Design; D008866:Microsurgery / Q000379:methods*; D012371:Robotics / Q000295:instrumentation*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D013552:Swine; D014821:Vitrectomy / Q000295:instrumentation*