Index Matching Fluid for Ophthalmic Laser Interface

Solution Overview

Problem

Laser surgery on the eye faces challenges due to differences in the index of refraction between the interface device and the eye, leading to inaccuracies in laser beam placement, especially when the interface surfaces are not flat, and previous solutions relied on complex mathematical algorithms.

Innovation Solution

A fluid-filled patient interface device with a curved lens and a fluid reservoir that matches the index of refraction of the cornea, eliminating refractive power effects without applanating the eye, using a glass plate, sidewall, and legs with an index matching fluid.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a traditional interface device with different index of refraction is used, then the device structure is simple, but the laser beam placement accuracy deteriorates due to refractive differences

Engineering Contradiction:

Improvelaser beam placement accuracyVSAvoidinterface device structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the optical parameter (index of refraction) of the interface device by filling it with fluid having an index of refraction that matches the cornea. This parameter change eliminates refractive differences at the interface, thereby improving laser beam placement accuracy without requiring complex mathematical compensation algorithms.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary substance (index-matching fluid) between the interface device and the cornea. This fluid acts as an optical intermediary that eliminates the refractive index mismatch, allowing the laser beam to pass through the interface device and into the eye without distortion or placement errors.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the interface device surfaces are made non-flat to follow eye curvature, then the comfort and fit improve, but the laser beam placement accuracy deteriorates due to increased refraction variations

Engineering Contradiction:

Improveinterface comfort and fitVSAvoidlaser beam placement accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent changes the optical parameter (index of refraction) of the interface device by filling it with fluid having an index of refraction that matches the cornea. This parameter change eliminates refractive differences at the interface, thereby improving laser beam placement accuracy without requiring complex mathematical compensation algorithms.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates optical homogeneity by using fluid with an index of refraction that matches the cornea throughout the interface device. This homogeneity ensures that light passes through the curved interface without experiencing varying refraction effects, thereby maintaining both comfort and precision.

Inventive Principle:

Principle #33Homogeneity

3Measurement precision

If applanation is used to flatten the cornea, then the refractive differences are reduced, but detrimental effects on the eye occur

Engineering Contradiction:

Improverefractive index matchingVSAvoidapplanation detrimental effects

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary substance (index-matching fluid) between the interface device and the cornea. This fluid acts as an optical intermediary that eliminates the refractive index mismatch, allowing the laser beam to pass through the interface device and into the eye without distortion or placement errors.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the optical parameter (index of refraction) of the interface device by filling it with fluid having an index of refraction that matches the cornea. This parameter change eliminates refractive differences at the interface, thereby improving laser beam placement accuracy without requiring complex mathematical compensation algorithms.

Inventive Principle:

Principle #35Parameter changes

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

The solution significantly reduces refractive differences, enhancing the accuracy of laser beam placement during eye surgery by matching the index of refraction of the interface device with the eye, thereby minimizing the detrimental effects of applanation.

Implementation Method 1

the laser beam must pass through the interface device which has a different index of refraction than the components of the eye that the laser beam must also pass through to reach the lens

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS8500723B2Liquid filled index matching device for ophthalmic laser procedures

Publication Date: 2013.08.06 LENSAR INC

AI summary

There is provided a device for use as an interface between a laser surgery device and the eye of a patient. The device is filled with a liquid that matches the index of refraction of the eye. The device further has a curved lens that follows the curvature of the outer surface of the patient's eye. In this manner the interface device, through which the laser beam must travel, has essentially the same index of refraction as the eye.