Towards robot-assisted vitreoretinal surgery: Force-sensing micro-forceps integrated with a handheld micromanipulator

Abstract

In vitreoretinal practice, controlled tremor-free motion and limitation of applied forces to the retina are two highly desired features. This study addresses both requirements with a new integrated system: a force-sensing motorized micro-forceps combined with an active tremor-canceling handheld micromanipulator, known as Micron. The micro-forceps is a 20 Ga instrument that is mechanically decoupled from its handle and senses the transverse forces at its tip with an accuracy of 0.3 mN. Membrane peeling trials on a bandage phantom revealed a 60–95% reduction in the 2–20 Hz band in both the tip force and position spectra, while peeling forces remained below the set safety threshold.

Motorized force-sensing micro-forceps with tremor cancelling and controlled micro-vibrations for easier membrane peeling

“…1.a [17]) uses easily replaceable disposable forceps jaws that are at this time taken from the standard 23 Ga Alcon disposable micro-forceps. The normally open jaws are fixed to the base via a set screw located on the lid.…”

“…(a) Motorized force-sensing micro-forceps: earlier prototype [17] (left) vs. more compact new prototype (right). (b) Components of the new design: The tip can be easily replaced to accommodate different jaw types for different surgical tasks and prolonged use.…”

“…Micron was shown to suppress tremor effectively, but it still has unexplored potential utility for tasks such as membrane peeling by operating in different modes rather than solely in tremor canceling mode. Developing such assistive modes for using Micron in a membrane peeling task first requires the advent of a proper micro-forceps tip that will firmly grasp the tissue while not interfering with Micron’s tremor canceling behavior and this was not available until recently [17]. …”

“…We recently presented a 2-DOF force-sensing micro-forceps for Micron (Fig. 1.a) [17]. This design was shown to be sufficiently compact and lightweight for Micron to operate properly, and benefits of such force-sensing tremor-canceling system for membrane peeling was demonstrated on artificial bandage phantoms.…”

Human eye phantom for developing computer and robot-assisted epiretinal membrane peeling

“…For this reason, a total of four different material preparations (liquid bandage, liquid bandage with blow drying, liquid bandage with corn starch, and Parafilm) were applied on two types of base material: aluminum and latex. Aluminum is potentially useful as an electrically conductive layer for detecting contact with the simulated retina surface during peeling experiments similar to those in [20]. In the current experiments, the base surfaces were flat in order to facilitate conducting a large number of tests.…”