Ophthalmic Laser Scanner Tilting for Lenticule Curvature
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Solution Overview
Problem
Existing ophthalmological laser systems struggle to make precise cuts in eye tissue with vertical components and varying focal depths, as they require slow vertical displacement of optical units and lenses, leading to reduced cutting speed and inaccuracies due to fixed horizontal scan lines that do not match the curvature of lenticules.
Innovation Solution
An ophthalmological apparatus with a dual scanner system, where the first scanner module provides fast scanning at a higher speed in a horizontal plane, and the second scanner module guides the pulsed laser beam along a work line transverse to the lenticule's meridians, allowing for dynamic tilt and adjustment of the scan line to match the lenticule's curvature without vertical focal displacements, enabling precise cuts with varying surface curvatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If vertical displacement of projection optical unit is used to achieve cuts with vertical component, then cutting precision is improved, but cutting speed deteriorates
Solution Approach 1:
The patent applies dynamics by making the scan line tilt angle variable rather than fixed. The scan line is dynamically tilted at different angles relative to the work plane depending on the current work target point, allowing the laser beam to follow the curved surface of the lenticule without requiring vertical displacement of the optical unit. This dynamic adjustment enables both high cutting precision for curved surfaces and maintains fast cutting speed.
Solution Approach 2:
The patent introduces a new degree of freedom by tilting the scan line out of the horizontal work plane into a three-dimensional path. Instead of moving the optical unit vertically (one-dimensional displacement), the system rotates the scan line around the optical axis, creating a conical scanning path that matches the lenticule curvature. This dimensional change eliminates the need for slow vertical optical displacement while achieving precise curved cuts.
2Productivity
If fixed horizontal scan lines are used for fast scanning, then scanning speed is improved, but manufacturing precision deteriorates due to mismatch with lenticule curvature
Solution Approach 1:
The patent transforms the fixed horizontal scan line into a dynamic, tiltable scan line that adapts to the lenticule's curvature. The tilt angle of the scan line is continuously adjusted according to the work target point position, allowing the fast scanning motion to naturally follow the curved surface geometry. This resolves the contradiction by making the scan pattern itself adaptable rather than forcing the optical unit to move vertically.
Solution Approach 2:
The patent changes the parameter of scan line orientation from fixed horizontal to variable tilt angle. By controlling the tilt angle as a function of the work target point position, the scan line parameters are dynamically adjusted to match the lenticule surface curvature. This parameter change enables the fast scanner to achieve both high speed and high precision without requiring slow vertical optical displacement.
3Manufacturing precision
If vertical focal displacement is performed to match lenticule curvature, then cutting precision is improved, but device complexity increases
Solution Approach 1:
The patent eliminates the need for complex vertical displacement mechanisms of the projection optical unit by introducing dynamic tilting of the scan line. Instead of moving heavy optical components vertically, the system uses angular rotation of the scan pattern around the optical axis. This reduces device complexity while maintaining cutting precision for curved surfaces.
Solution Approach 2:
The patent replaces the mechanical system of vertically displacing the projection optical unit with an optical control system that tilts the scan line through angular rotation. Instead of physical movement of optical components, the system uses controlled rotation of the laser beam path to achieve the same cutting precision, thereby reducing mechanical complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for flexible and precise cutting of lenticules with tilted or curved trajectories, improving matching to the lenticule's surface curvature and reducing the need for vertical focal adjustments, thereby enhancing cutting speed and accuracy.
Implementation Method 1
an ophthalmological apparatus for working on eye tissue (20), in particular for cutting a lenticule (21) in the eye tissue (20), with a laser source (11) that is configured to produce a pulsed laser beam (L)
Implementation Method 2
a focusing optical unit (16) that is configured to focus the pulsed laser beam (L) into the eye tissue (20)
Implementation Method 3
a scanner system (100) for guiding the pulsed laser beam (L) onto work target points (F) in the eye tissue (20); with movable mirrors being used to deflect the light beams and/or the laser pulses
Data Source
AI summary
For the purposes of working on eye tissue, an ophthalmological apparatus comprises a laser source that is configured to produce a pulsed laser beam, a focusing optical unit that is configured to focus the pulsed laser beam into the eye tissue, and a scanner system for deflecting the pulsed laser beam onto work target points in the eye tissue. The scanner system is configured to guide the pulsed laser beam onto work target points along a scan line that extends across a work line at an alignment angle and to tilt the scan line depending on the work target point on the work line in such a way that the scan line extends substantially along an outer face of a lenticule to be cut in the eye tissue.