Compact Microscope Stack Integrating NIR OCT and Visible Imaging

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Solution Overview

Problem

Current surgical microscopes in ophthalmic surgery face challenges in correlating the position of near-infrared (NIR) OCT measurement beams with visible light images, especially across different microscope designs and magnification levels, leading to potential inaccuracies and inefficiencies during procedures.

Innovation Solution

A combined near-infrared imaging and visible imaging system is integrated into a compact microscope stack, using an IR camera to directly capture NIR OCT measurement beams and a visible camera to provide digital visualization, allowing for flexible operation across various microscope designs without increasing the stack height, thereby enabling accurate correlation of NIR beam locations with eye tissue.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an OCT system is integrated into a surgical microscope to provide additional imaging information, then the imaging capability is improved, but the device complexity increases and the stack height increases

Engineering Contradiction:
Improveimaging capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the OCT imaging system with the visible light surgical microscope into a single integrated device. The OCT light source, scanning mirrors, and detection system are merged with the microscope's optical path, allowing simultaneous acquisition of both visible and NIR images without requiring separate devices. This integration improves versatility while managing device complexity through unified design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The surgical microscope is designed to perform multiple functions: visible light imaging for surgical visualization, NIR imaging for enhanced tissue contrast, and OCT for cross-sectional structural information. The system uses a single optical platform that can switch between or combine these different imaging modes, making the device universal for various surgical imaging needs.

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

2Adaptability or versatility

If an OCT system is integrated into a surgical microscope to provide additional imaging information, then the imaging capability is improved, but the stack height increases

Engineering Contradiction:
Improveimaging capabilityVSAvoidstack height
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The OCT system components are nested within the existing microscope structure. The OCT light source is positioned within the microscope body, scanning mirrors are integrated into the optical path, and the detection system is housed within the same enclosure. This nesting approach allows the OCT functionality to be embedded without significantly increasing the overall stack height of the microscope.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes the vertical dimension efficiently by arranging optical components in a compact folded optical path. The NIR light path is directed through dichroic mirrors and beam splitters that redirect light in multiple dimensions, allowing the OCT imaging path to be incorporated without extending the microscope stack height in the primary vertical direction.

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

3Measurement precision

If manual correlation methods are used to correlate OCT beam positions with visible images, then the measurement precision is improved, but the time consumption increases

Engineering Contradiction:
Improvecorrelation accuracyVSAvoidtime consumption
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system provides real-time feedback by displaying the correlated position of the NIR/OCT measurement beam overlaid on the visible light image. The controller continuously monitors the beam position from the NIR camera and updates the overlay indication on the display device, allowing the surgeon to immediately see where the OCT beam is targeting without manual correlation steps. This automated feedback loop maintains high correlation accuracy while eliminating time-consuming manual procedures.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual mechanical correlation methods with an automated optical and electronic system. Instead of physically adjusting components or manually aligning images, the system uses the NIR camera to optically track the beam position and the controller to electronically compute and display the correlated location. This substitution of mechanical/manual operations with automated optical-electronic systems maintains precision while dramatically reducing time consumption.

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

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 solution improves surgical workflow and patient safety by allowing quick and accurate determination of NIR beam locations within the surgical field, reducing the need for manual correlation and enhancing ergonomic usability.

Implementation Method 1

a dichroic mirror used to reflect the first portion of the NIR light and transmit the second portion of the visible light

Methodology Applied
Scientific EffectDichroic reflection: Dichroic Filter

Implementation Method 2

a beam combiner used to reflect the display light onto the visible light transmitted to the second ocular

Methodology Applied
Scientific EffectBeam combination: Reflection

Data Source

PatentEP3678531B1Combined near infrared imaging and visible imaging in a compact microscope stack
Publication Date: 2022.11.09 ALCON INC
  • EP3678531B1 patent drawingFigure 1
  • EP3678531B1 patent drawingFigure 2A
  • EP3678531B1 patent drawingFigure 2B

AI summary

Both visible and IR cameras are integrated without an increase in an optical stack height of a surgical microscope used for ophthalmic surgery. The IR camera may be used to directly and intraoperatively capture a scanning OCT measurement beam, which uses NIR light that is invisible to the human eye. An IR image from the IR camera taken from the same surgical field as displayed intraoperatively to a user of the surgical microscope may be displayed in an ocular to the user, enabling visualization of a location of an OCT scan along with actual visible images of the surgical field.