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Updated: Aug 14, 2026
Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer
Published on: September 28, 2015
Effects on phacoemulsification efficiency and chatter at variable longitudinal ultrasound settings when combined with
Austin Bohner1, John S Peterson, Alex J Wright
1From the Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah (Bohner, Peterson, Wright, Mamalis, Bernhisel, Zaugg, Barlow, Olson, Pettey), University of Utah School of Medicine (Bohner, Peterson, Wright), Salt Lake City, USA.
Purpose:
To evaluate longitudinal power settings for optimally efficient lens fragment removal, using the Centurion machine.
Setting:
John A. Moran Eye Center, University of Utah, Salt Lake City, USA.
Design:
Experimental study.
Methods:
Porcine lens nuclei were cut into 2.0 mm cubes. Experiments were conducted at 100% torsional power; vacuum set at 500 mm Hg, aspiration 50 mL/min, and intraocular pressure 110 mm Hg. A 20-degree tip with a 30-degree bevel was used. Longitudinal power was tested between 20% and 100%. Efficiency (time for fragment removal) and chatter (the number of times the fragment bounced from the tip) were measured.
Results:
A linear increase in efficiency was observed from 20% to 100% longitudinal power (R = 0.9281, slope = -0.0271). An efficiency slope change occurred at 60% power, with the largest incremental change in efficiency between 20% and 60% (R = 0.9756, slope = -0.0394) and a lesser change between 60% and 100% (R = 0.9827, slope = -0.0121). Chatter analysis showed minimal events at 20% to 60%, but a significant increase at >80% (P = .005). This increase appeared to be incremental (R = 0.8929).
Conclusions:
Increasing longitudinal power, with all other settings constant, increased efficiency. Greatest efficiency gains were observed between 20% and 60%. At 80% and 100%, chatter events increased significantly. With a goal of recommending optimally efficient settings while minimizing excess energy and chatter, adding 60% of longitudinal power to 100% torsional power was shown to be the best setting to increase efficiency and avoid repulsion in these vacuum and aspiration settings.
