Automated Refractive Surgery Planning with Volumetric Corneal Modeling

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Solution Overview

Problem

Current automated planning systems for refractive surgical treatments are inadequate in accurately determining the biomechanical effects on the eye, due to high complexity and reliance on simplified cornea models, which can lead to significant deviations and increased risk of complications.

Innovation Solution

A planning device and procedure that utilize predetermined properties of the eye to calculate volumetric parameters, characterizing the impact of planned refractive surgical treatments on the eye, thereby improving the precision of biomechanical effect prediction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a standard corneal model with simplified geometric approximation is used, then the calculation complexity is reduced and planning can be performed routinely, but the measurement precision of biomechanical effects deteriorates significantly

Engineering Contradiction:
Improveroutine planning capabilityVSAvoidbiomechanical effect prediction accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent transforms the corneal model from a simplified geometric approximation to a personalized model by changing parameters such as corneal thickness, curvature, and volumetric characteristics based on individual patient measurements. This allows routine planning while improving prediction accuracy through personalized parameters rather than generic models.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a virtual copy or digital twin of the patient's cornea using preoperative imaging data (OCT, topography). This virtual model replicates the actual corneal anatomy and biomechanical properties, enabling accurate prediction of surgical effects without complex manual calculations while maintaining routine workflow.

Inventive Principle:
Principle #26Copying

2Measurement precision

If complex model calculations are performed to accurately determine biomechanical effects, then the measurement precision improves, but the device complexity and time required increase significantly

Engineering Contradiction:
Improvebiomechanical effect prediction accuracyVSAvoidcalculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex manual mathematical calculations with automated computer-based modeling. The system uses software algorithms that automatically process preoperative data, generate personalized corneal models, and calculate biomechanical effects, eliminating the need for surgeons to perform complex calculations manually while maintaining high precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediate computational model that acts as a mediator between preoperative measurements and surgical planning. This virtual corneal model serves as an intermediary that translates raw imaging data into actionable biomechanical predictions, simplifying the overall system while improving accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the depth of material removal is increased to correct refractive error, then the refractive correction improves, but the reliability of the treatment deteriorates due to increased risk of complications

Engineering Contradiction:
Improverefractive correction accuracyVSAvoidtreatment safety
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the personalized corneal model is continuously updated with preoperative measurements (OCT, topography, pachymetry) to accurately predict the remaining corneal strength after material removal. This feedback allows the system to optimize the depth and distribution of ablation to achieve the desired refractive correction while maintaining corneal safety margins.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies beforehand cushioning by using the personalized virtual model to simulate and predict the biomechanical consequences of material removal before the actual surgery. The system identifies potential safety issues in advance and adjusts the treatment plan to prevent complications, cushioning against unexpected outcomes through preoperative planning.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP4076309B1Planning apparatus, refractive laser system and method for automated planning of a refractive surgical treatment
Publication Date: 2025.04.09 CARL ZEISS MEDITEC AG
  • EP4076309B1 patent drawingFigure 1
  • EP4076309B1 patent drawingFigure 2A~2B
  • EP4076309B1 patent drawingFigure 3A~3B

AI summary

The present invention relates to a planning apparatus (36) for automated planning of a refractive surgical treatment of an eye by means of a refractive laser system (10). The planning apparatus (36) is designed to plan the refractive surgical treatment of the eye on the basis of predetermined properties of the eye and to calculate at least one volumetric parameter of the cornea of the eye using the predetermined properties of the eye, wherein the volumetric parameter characterizes an effect of the planned refractive surgical treatment on the eye. The invention also relates to a refractive laser system, to a method, to a computer program product and to a computer-readable storage medium.