Intraocular snake integrated with the steady-hand eye robot for assisted retinal microsurgery

Abstract

Due to the confined intraocular space and physical constraints in tool manipulation, snake-like robots have a significant potential for use in retinal microsurgery. By enhancing the dexterity at the tool tip, not only the operable space on the retina can be enlarged, but also the delicate target tissues can be reached at an optimal angle minimizing the damage and making the operation much easier. In this study, we present an improved version of our earlier integrated intraocular snake (IRIS) robot, and combine it with another robotic assistant: the cooperatively controlled Steady-Hand Eye Robot (SHER). SHER is used to drive IRIS close to the retina with precision, while IRIS makes omnidirectional bends by combining its yaw and pitch motions and provides a significantly enhanced intraocular dexterity while holding the sclerotomy port fixed. For precise control of IRIS, its snake-like tip actuation has been characterized through experiments considering both a free tool tip and external loading at the tool tip. The workspace analysis showed ±45° yaw and pitch with excellent repeatability (±1°) despite the highly miniaturized articulated segment length (3 mm) and very thin shaft (Ø 0.9 mm). Our preliminary experiments in an artificial eye model have shown feasibility in reaching targets requiring bends up to 55° accurately.

Robotic Retinal Surgery

“…In the years that followed, other snake-like continuum devices have been developed that enable the instrument's end-effector to approach and manipulate the retina from arbitrary orientation. The system from Johns Hopkins University [84,179] is quite similar to the continuum device of the IODR, but is deployed from the SHER platform (see §5.3). The system from Imperial College London uses nested superelastic tubes, to be deployed from a unit located on the microscope.…”

Improved Integrated Robotic Intraocular Snake: Analyses of the Kinematics and Drive Mechanism of the Dexterous Distal Unit

“…Furthermore, the instrument should be detachable from the motor unit for cleaning, sterilization, and attachment of various types of surgical tools. As a continuation of our previous works [29,31], we proposed an improved integrated robotic intraocular snake (I 2 RIS) [32].…”

“…The original dexterous distal unit (DDU) of the IRIS is based on the principle of the variable neutral-line mechanism [30]. Subsequently, a more compact actuation unit with better resolution for the IRIS, preliminary operational evaluation of the IRIS, and its integration with the SHER system were presented in [31]. However, from the perspective of clinical use, the previously developed IRISs [29,31] and conventional system [28] are still large, heavy, and mechanically complex.…”

“…Subsequently, a more compact actuation unit with better resolution for the IRIS, preliminary operational evaluation of the IRIS, and its integration with the SHER system were presented in [31]. However, from the perspective of clinical use, the previously developed IRISs [29,31] and conventional system [28] are still large, heavy, and mechanically complex. A more compact and simpler IRIS is desired for integration in robotic systems for retinal surgery.…”

Toward Improving Safety in Neurosurgery with an Active Handheld Instrument

“…Cooperative control for precision targeting in neurosurgery was explored in [5,6]. In [62,59] and in [22], cooperatively controlled robots were proposed with applications in retinal surgery.…”