Lens delivery system cartridge
View Patent ↗A cartridge for an IOL delivery system that has an injector tip geometry designed to reduce stresses at the incision wound edges generated during insertion of an IOL into an eye is disclosed. The injector tip geometry includes a tubular nozzle having a modified elliptical cross section. The injector tip geometry reduces stresses generated reduce the likelihood of tearing or overstretching the wound during cartridge tip insertion and residence time in the wound while the lens is being delivered into the eye.
1. An intraocular lens delivery system cartridge, comprising:
a body, and
a tubular nozzle connected to the body and projecting distally from the body, the nozzle having a cross-section, the cross-section having a shape defined by:
a portion of an ellipse disposed in a first quadrant and a second quadrant of a Cartesian coordinate system, the ellipse having a center that is offset from the origin of the Cartesian coordinate system in a direction along a negative portion of an ordinate axis of the Cartesian coordinate system, the portion of the ellipse defined as a first curve; and
a second curve defined as a mirror image of the first curve mirrored about an abscissa axis of the Cartesian coordinate system, the first curve and the second curve forming first and second points at locations where the first curve and the second curve intersect the abscissa axis of the Cartesian coordinate system; and
circular arcs formed at opposing ends of the cross-section proximate the first and second points, each circular arc defined as a portion of a circle joining the first curve and the second curve that is tangent to both the first curve and the second curve and that has a 90 degree tangent line at a point along the abscissa axis crossed by the circular arc.
2. The cartridge of claim 1 , wherein the ellipse has an ellipse eccentricity of 0.65.
3. The cartridge of claim 1 , wherein a distance defined along the abscissa axis between locations where the circular arcs intersect the abscissa axis defines a width of the cross-section,
wherein a portion of the cross-section comprises a portion of one of circular arcs extending from the abscissa axis to the first curve, a portion of the first curve extending between the circular arcs, and a portion of the other of the circular arcs extending from the first curve to the abscissa axis,
wherein a length of the portion of the cross-section defines an arc length, and
wherein a ratio of the arc length to the width of the cross-section is 1.386.