Ophthalmic Fixation Mark Projection for Eye Alignment

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Solution Overview

Problem

Existing ophthalmological devices face challenges in aligning the eye for diagnostic or therapeutic purposes without the viewing direction coinciding with the optical axis, particularly in positioning and orienting the eye for precise alignment relative to the device.

Innovation Solution

A device with a positionable fixation light source that generates a fixation mark, which is projected via the ophthalmological device's imaging optics, allowing the eye to be aligned by foveal focusing at different distances and angles relative to the optical axis, enabling precise alignment of the eye with respect to the device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the patient's eye is positioned on the optical axis of the device using traditional fixation methods, then the alignment along the optical axis is achieved, but the ability to align the eye in other directions (non-optical axis alignment) is limited

Engineering Contradiction:
Improvealignment direction flexibilityVSAvoideye positioning accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The fixation mark is made dynamically positionable at different locations in the visual field through electronic control of the fixation light source, allowing the eye to be aligned in various directions while maintaining precise positioning capability through dynamic adjustment

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A positionable fixation mark serves as an intermediary element that can be placed at different locations to guide eye alignment in various directions, enabling flexible positioning without compromising accuracy through the use of a controllable light-based marker

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a separate fixation light source is used to align the eye, then the fixation mark can be projected independently, but the integration with the ophthalmological device's optical system becomes complex

Engineering Contradiction:
Improvefixation mark projection flexibilityVSAvoidoptical system integration
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The separate fixation light source is optically integrated with the ophthalmological device's imaging optics through beam combining techniques, allowing independent control of the fixation mark while sharing the optical path and reducing overall system complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fixation light source is designed to work through the existing imaging optics of the ophthalmological device, making the imaging optics serve dual purposes: both imaging and fixation mark projection, thereby reducing the need for separate optical components

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 accurate and defined positioning of the eye relative to the optical axis of ophthalmological devices, facilitating effective diagnostic and therapeutic procedures, including diopter compensation and adaptation for refractive changes, while allowing alignment in any direction, including the optical axis.

Implementation Method 1

a fixation light source (4) for generating a positionable fixation mark (FM)

Methodology Applied
Scientific EffectLight: Light

Implementation Method 2

via whose imaging optics (7) the fixation mark (FM) is projected in the direction of the eye (6) to be examined and/or treated

Methodology Applied
Scientific EffectOptical imaging: Lens

Data Source

PatentEP1993431B1Devices and methods for defined orientation of an eye
Publication Date: 2016.09.28 CARL ZEISS MEDITEC AG
  • EP1993431B1 patent drawingFigure 1~3
  • EP1993431B1 patent drawingFigure 4

AI summary

The present solution concerns the orientation of an eye for diagnostic or therapeutic purposes, where the line of sight does not necessarily have to coincide with the optical axis of the examination or treatment appliance. The device according to the invention for orienting an eye consists of a fixing light source (4) for generating a positionable fixing mark (FM) and of a means for coupling this into a beam path of an ophthalmological appliance, through whose focusing optics (7) the fixing mark (FM) is projected onto the eye (6) to be examined and/or treated, and of a control unit with which the image (FM') of the fixing mark can be presented at different distances and angles in relation to the optical axis (5) of the ophthalmological appliance, such that the eye (6) to be examined and/or treated directs itself by foveal focussing at this fixing mark (FM) and assumes a defined position with respect to the optical axis (5) of the ophthalmological appliance. The proposed technical solution can in principle be applied in all ophthalmological appliances used for diagnostic and/or therapeutic purposes. However, the solution is of particular importance in observing and/or treating the anterior portions of the eye.