Astigmatism Measurement with Cylinder-Independent Vector Analysis
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Solution Overview
Problem
Existing methods for determining astigmatism are cumbersome, inaccurate, and dependent on the practitioner's expertise, leading to inconsistent and imprecise prescriptions due to difficulties in handling cross cylinders and defining referential axes.
Innovation Solution
A method and device using vector decomposition in a J0/J45 coordinate system to determine astigmatism independently of the cylinder value, with adjustable lenses and a control panel for precise adjustments, allowing accurate determination of astigmatism through a Jackson cross cylinder procedure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the Jackson Cross Cylinder method is used to determine astigmatism, then measurement precision is improved, but device complexity and ease of operation deteriorate due to the difficulty in handling cross cylinders and comparing lens positions
Solution Approach 1:
The patent replaces the manual mechanical handling of cross cylinders with an automated motorized system. The control panel electronically adjusts the cylinder lens positions and rotations, eliminating the need for the practitioner to manually manipulate cross cylinders. This substitution maintains measurement precision while dramatically improving ease of operation.
Solution Approach 2:
The control panel serves as an intermediary between the practitioner and the cross cylinder system. Instead of directly handling complex cross cylinder mechanics, the practitioner interacts with the simplified control panel interface, which automatically manages lens positioning, rotation, and presentation sequences.
2Measurement precision
If the classical refraction process using cross cylinders is used, then astigmatism can be determined, but reliability deteriorates due to high dependence on practitioner experience and competencies
Solution Approach 1:
The system performs self-adjustment and self-calibration through automated control. The motorized assembly automatically positions lenses, adjusts cylinder powers, and manages the refraction sequence without requiring practitioner expertise in manual cross cylinder techniques. This automation ensures consistent, reliable results independent of practitioner experience level.
Solution Approach 2:
The system incorporates feedback mechanisms where the control panel monitors patient responses and automatically adjusts lens parameters based on this feedback. This closed-loop control ensures accurate astigmatism determination while reducing variability between different practitioners.
3Measurement precision
If manual cross cylinder adjustment is used, then the procedure can be performed, but productivity deteriorates due to the time-consuming nature of the process
Solution Approach 1:
The motorized system implements periodic, automated presentation of different cylinder lens configurations at predetermined intervals. This systematic periodic action streamlines the refraction process, maintaining measurement precision while reducing the overall time required compared to manual adjustment methods.
Solution Approach 2:
The system dynamically adjusts lens parameters in real-time based on the refraction progress. The motorized assembly can quickly transition between different cylinder powers and axis orientations, optimizing the refraction workflow and improving productivity while preserving accuracy.
4Productivity
If cross cylinder positions are changed rapidly, then productivity is improved, but measurement precision deteriorates because the person cannot keep track of previous image qualities
Solution Approach 1:
The control panel provides immediate visual and auditory feedback to the patient, clearly indicating when lens positions change and what configuration is currently presented. This enhanced feedback mechanism allows for faster position changes while maintaining patient comprehension and response accuracy.
Solution Approach 2:
The system presents lens configurations in a predetermined optimized sequence designed to maximize patient understanding. Before rapid position changes occur, the system prepares the next configuration in advance, allowing smooth transitions that maintain precision while improving overall refraction speed.
Data Source
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AI summary
Method for determining astigmatism of an eye of a person, the method comprising - a measuring device providing step during which a measuring device adapted to run a Jackson cross cylinder procedure is provided, - a first vector determining step, during which the components of a first vector of the cylinder in a two-dimensional vector cylinder representation are determined, - a second vector determining step, during which the components of a second vector of the cylinder in the two-dimensional vector cylinder representation are determined wherein the second vector components being determined such that the Euclidian distance between first and second vector is independent of the value of the cylinder.