Corneal Deformation Compensation in Laser Vision Correction
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Solution Overview
Problem
Current methods for surgical correction of defective vision, such as LASIK, are limited in their ability to achieve complex corrections and require significant computational effort to produce precise control data for laser surgery.
Innovation Solution
A device and method for generating control data that adapt to the deformation of the cornea during laser surgery, allowing for the precise calculation of the radius of curvature and volume removal to achieve complex optical corrections with reduced computational effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional LASIK methods are used to correct defective vision, then simple refractive errors can be corrected, but complex corrections such as presbyopia cannot be achieved and computational effort remains high
Solution Approach 1:
The patent applies preliminary action by pre-calculating the deformation state of the cornea during surgery and using this information to adjust the control data before the actual laser procedure. The method determines the deformation of the cornea in advance and transforms the correction surface coordinates accordingly, allowing complex corrections to be achieved without increasing real-time computational complexity during surgery.
Solution Approach 2:
The patent utilizes parameter changes by transforming the coordinates of the correction surface based on the determined deformation parameters of the cornea. By changing the coordinate system parameters to account for corneal deformation, the method enables complex corrections including presbyopia while maintaining computational efficiency through predetermined deformation models.
2Measurement precision
If the cornea is pressed against a contact surface during laser surgery to stabilize it, then positioning precision is improved, but the cornea deforms and requires additional computational transformation
Solution Approach 1:
The patent resolves this contradiction by performing the coordinate transformation in advance, before the actual laser surgery begins. The deformation caused by pressing the cornea against the contact surface is calculated beforehand, and the correction surface coordinates are transformed accordingly. This preliminary calculation eliminates the need for complex real-time transformations during surgery, maintaining both positioning precision and computational simplicity.
3Ease of manufacture
If a correction surface is predetermined for the non-deformed cornea, then the correction plan is simple to create, but it does not account for actual surgical conditions where the cornea is deformed
Solution Approach 1:
The patent maintains correction plan simplicity while improving accuracy by transforming the predetermined correction surface coordinates using the determined deformation parameters. The basic correction plan remains simple to create, but the coordinate transformation adjusts it to account for actual surgical conditions where the cornea is pressed against the contact surface, ensuring both ease of planning and surgical precision.
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
Enables the achievement of more extensive and complex corrections of defective vision, such as presbyopia, with improved precision and reduced computational complexity, while accounting for corneal deformation during surgery.
Implementation Method 1
the control data are adapted to control a laser which cuts cornea tissue by irradiating laser radiation into the cornea of the eye
Data Source
AI summary
A device for producing control data for a laser device for the surgical correction of defective vision. The device produces the control data such that the laser emits the laser radiation such that a volume in the cornea is isolated. The device calculates a radius of curvature RCV* to determine the control data, the cornea reduced by the volume having the radius of curvature RCV* and the radius of curvature being site-specific and satisfying the following equation: RCV*(r,φ)=1/((1/RCV(r,φ))+BCOR(r,φ)/(nc−1))+F, wherein RCV(r,φ) is the local radius of curvature of the cornea before the volume is removed, nc is the refractive index of the material of the cornea, F is a coefficient, and BCOR(r,φ) is the local change in refractive force required for the desired correction of defective vision in a plane lying in the vertex of the cornea, and at least two radii r1 and r2 satisfy the equation BCOR(r=r1,φ)≠BCOR(r=r2,φ).