A novel phacoemulsification needle with scissor-like motion end effector for reducing heat generation at cornea incision

Abstract

In this paper, we designed a novel scissor-like phacoemulsification needle for efficiently disrupting cataract with low risk of corneal burns. The proposed phaco needle consists of a needle shaft and an end effector with two slight beams connected at the shaft tip by an inverse symmetrical groove structure. The longitudinal driving force transmits through the needle shaft and converts into opposite transversal forces at the groove structure based on elastic wave reflection. These opposite transversal forces excite efficient scissor-like vibration at slight beams, as well as restrict the shaft deflection to reduce the frictional heat generation between the needle sleeve and shaft at the cornea incision. In the paper, the design principle was presented firstly. Next, a scissor-like needle was designed, simulated, fabricated and experimentally characterized. In the performance test, the scissor-like needle showed high efficiency to disrupt tissue. Moreover, under the same conditions, the proposed needle generated obviously lower frictional heat than the conventional longitudinal needle at the needle shaft, thus making it a successful design for reducing the risk of burns thoroughly in cataract removal application.