Constant force intraocular lens injector

摘要

An intraocular lens injection device comprises a tubular housing with a passageway extending along its longitudinal axis and a plunger shaft disposed within and moveable along the passageway. The tubular housing and the plunger shaft have frictional engaging features that are configured to produce a varying plunging friction as the plunger is moved along its operating range, to offset changes in the plunging resistance that arise from injecting the IOL into the eye. The variable plunging friction may include one or more step changes in unloaded plunging friction, or a curved variation in plunging friction, or both, along at least a portion of the operating range of the plunger shaft. In some embodiments, a slot of varying width in the housing frictionally engages a tab extending transversely from the plunger shaft. In others, a contoured surface on the plunger shaft frictionally engages an orifice in the tubular housing.

主权项

1. A device for injecting an intraocular lens into an eye, the device comprising:
a tubular housing having a longitudinal axis and a passageway along the longitudinal axis; an orifice formed and fixed within the passageway of the tubular housing, the orifice having an opening, a cross-sectional size of the opening of the orifice being different than a cross-sectional size of the passageway, the cross-section of the orifice and the cross-section of the passageway being transverse to the longitudinal axis; and a plunger shaft disposed within and moveable along the passageway of the body over an operating range, the plunger shaft comprising a contoured surface that includes a contour that varies in a direction along a longitudinal axis of the plunger shaft, the contoured surface operable to engage the orifice to vary plunging friction along the operating range to offset one or more changes in plunging resistance arising from injection of the lens into the eye.