Ophthalmologic Microscope Illumination Device

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Solution Overview

Problem

Current ophthalmological surgical microscopes face challenges in achieving a homogeneous, bright 'red reflex' and good contrasting of phase objects during cataract surgery, while also dealing with disruptive reflections that can affect the observation field, particularly in coaxial illumination systems.

Innovation Solution

The surgical microscope incorporates an illumination device with optics designed according to the Köhler illumination principle, featuring a reflex diaphragm to suppress disruptive reflections and ensure even illumination, using a light source that can be projected to infinity and a condenser to enclose the objective element, with the reflex screen positioned to minimize stray light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If coaxial illumination is used to achieve homogeneous red reflex, then illumination homogeneity is improved, but phase object contrast deteriorates

Engineering Contradiction:
Improvered reflex homogeneityVSAvoidphase object contrast
Core Design Contradiction:
Illumination intensityVSMeasurement precision

Solution Approach 1:

The illumination beam is divided into two separate partial beams that travel along different paths. One beam provides coaxial illumination for homogeneous red reflex, while the other beam path is configured to maintain phase object contrast. The beams are later recombined to illuminate the surgical field simultaneously, resolving the contradiction between illumination homogeneity and phase contrast.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution moves from a single-dimensional illumination approach to a two-dimensional beam configuration. By creating separate beam paths in different spatial dimensions and then combining them, the system achieves both coaxial illumination benefits and phase contrast preservation that cannot be obtained with a single beam path.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If illumination angle is reduced to 0 degrees for coaxial illumination, then red reflex homogeneity is improved, but disruptive reflections increase

Engineering Contradiction:
Improvered reflex homogeneityVSAvoiddisruptive reflections
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The illumination is segmented into two partial beams with different angular characteristics. One beam provides the coaxial 0-degree illumination for homogeneous red reflex, while the other beam is configured at a different angle to illuminate phase objects without creating disruptive reflections in the observation path.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the illumination system provide different illumination qualities. The coaxial beam path provides uniform illumination for the red reflex, while the separate beam path provides angled illumination optimized for phase object contrast without generating harmful reflections. Each beam path is optimized for its specific function.

Inventive Principle:
Principle #3Local quality

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 configuration provides a stable, even 'red reflex' and enhanced contrast across the pupil area, reducing disruptive reflections and maintaining light efficiency without the need for complex lenses or light loss, thus improving surgical visibility and precision.

Implementation Method 1

The illumination device (10) has illumination optics (11) which are constructed according to the Köhler illumination principle

Methodology Applied
Scientific EffectKöhler illumination:

Implementation Method 2

at least one reflex diaphragm (18) is provided for covering reflected light which is radiated from the surface of an objective element (19)

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

a condenser (17) which encloses an objective element (19)

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP1955103B1Microscope for ophthalmologic surgery
Publication Date: 2018.05.02 CARL ZEISS MEDITEC AG
  • EP1955103B1 patent drawingFigure 1

AI summary

An illumination device (10) for one, two or more observation beam paths each having an observation device which has an observation beam, in particular for an operation microscope is, inter alia, described, having at least one light source (12) for production of at least one illumination beam for illumination of an object (13) to be observed, in particular of an eye to be observed, with the at least one illumination beam running coaxially with respect to an observation beam. In order to allow disturbing reflections to be suppressed, the invention provides for the illumination device (10) to have illumination optics (11) which are designed on the Köhler illumination principle, and to be provided in the at least one reflection shutter (18) in order to avoid reflected light from the surface of an objective element (19). A correspondingly improved observation device is also described.