Abstract
Purpose:
In vitreoretinal surgery, limited manual precision curtails development of new, precision-enabled surgeries. Robot assistance can support surgeons in performing existing vitreoretinal procedures with higher reproducibility and enable new procedures.<br /> Intuitive control of any robotic system is an important prerequisite. An intuitive motion controller allowing the appropriate transfer of information and feedback between a surgeon and a robotic assistant are assessed for vitreoretinal surgical applications.
Methods:
The motion controller mimics the instrument by: (1) having a pen like grip held at the tip as if manipulating the tip of an intraocular instrument;<br /> (2) having a remote center of motion comparable to the instrument usage, resulting in control in ‘eye coordinates’ as opposed to standard control in cartesian coordinates; (3)being able to automatically mirror motion to the same degree as instruments entering through the pars plana.<br /> Position encoders measure the motion input, from which control algorithms determine the motion output to the instrument manipulator, These algorithms further, enable tremor filtering, motion scaling and advanced support in e.g. semi automated motion patterns such as piercing motions.<br /> The motion controller is positioned within close reach of the surgical area, enabling hybrid control, i.e., using one hand to hold a manual instrument and the other to control the robot assisted instrument, while using the conventional surgical setting including the microscope. Coupling of manipulator and motion controller is insured by pressing a button on the side of the controller.
Results:
13 surgeons have evaluated the motion controller. The kinematic design and “eye coordinates” were seen as intuitive. Hybrid surgery, with one hand using the motion controller and the other a light pipe was experienced as inherently feasible. Being able to couple or uncouple the motion controller from the manipulator, or the ability to pause a task by releasing the actuating button was considered most valuable.
Conclusions:
Mimicking the instrument motion by using ‘eye coordinates’ was seen as intuitive and desireable. Use in a mixed setting (robotic assistance) was easily integrated in existing procedures and with little interference during the non robotic portion of the surgery. Access to the surgical field was not hindered. Further development will focus on optimizing the gripper ergonomy.