Rolling Shutter Fluorescence Imaging with Liquid Crystal Light Shuttering

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Solution Overview

Problem

Rolling shutter imagers are not currently used for fluorescence visualization in open-field surgeries due to ambient lighting contamination, which is particularly challenging for them.

Innovation Solution

Employ a liquid crystal light shutter that selectively blocks visible light while allowing fluorescence excitation light to reach the imager, enabling the use of rolling shutter imagers by transitioning between open and closed states based on control signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a rolling shutter imager is used for fluorescence visualization, then cost-effectiveness and compactness are improved, but ambient light contamination increases

Engineering Contradiction:

Improvecost-effectivenessVSAvoidambient light contamination

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by closing the mechanical shutter before ambient light can contaminate the sensor during the rolling shutter readout process. The shutter is positioned to block the optical path in advance, preventing harmful ambient light from reaching the sensor during critical exposure periods, thereby resolving the contradiction between using cost-effective rolling shutters and preventing ambient light contamination.

Inventive Principle:

Principle #10Preliminary action

2Volume of moving object

If a rolling shutter imager is used for fluorescence visualization, then device compactness is improved, but image quality deteriorates due to ambient light interference

Engineering Contradiction:

Improvedevice compactnessVSAvoidimage quality

Core Design Contradiction:

Volume of moving objectVSMeasurement precision

Solution Approach 1:

The mechanical shutter is operated in advance to close before ambient light contamination can occur during the rolling shutter readout. This preliminary blocking action prevents ambient light from degrading image quality, allowing the system to maintain compactness while preserving fluorescence imaging quality.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If ambient light is allowed to reach the imager, then ease of operation is improved, but fluorescence imaging accuracy deteriorates

Engineering Contradiction:

Improveease of operationVSAvoidfluorescence imaging accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The system automatically closes the mechanical shutter in advance during fluorescence imaging modes, preventing ambient light from reaching the sensor. This preliminary protective action maintains fluorescence imaging accuracy while requiring minimal user intervention, as the shutter control is integrated into the imaging system's operation.

Inventive Principle:

Principle #10Preliminary action

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 approach reduces ambient light contamination, resulting in clearer fluorescence imaging data and allows rolling shutter imagers to be used effectively in open-field surgical applications.

Implementation Method 1

Employ a liquid crystal light shutter that selectively blocks visible light while allowing fluorescence excitation light to reach the imager

Methodology Applied

Scientific EffectLiquid crystal light shutter: Liquid Crystals

Implementation Method 2

The fluorescence excitation illumination source, such as an infrared light illumination source, can provide illumination to the imaged tissue to excite the fluorophores (or fluorochromes) to produce fluorescence emission

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS20250213101A1Systems and methods for providing medical fluorescence imaging using a rolling shutter imager and a liquid crystal light shutter

Publication Date: 2025.07.03 STRYKER CORP

AI summary

The present disclosure relates to techniques for imaging tissue of a subject. An exemplary method comprises transitioning a (liquid crystal) light shutter to an open state to allow reflected light from illuminating the tissue of the subject with a visible-light illumination source to accumulate charge at a plurality of rows of pixels of an imager; transitioning the light shutter to a closed state to prevent the imager from receiving visible light; during a first readout period, reading accumulated charge to produce a first set of imaging data; while the light shutter is in the closed state, illuminating the tissue of the subject with a fluorescence excitation illumination source; during a second readout period after the first readout period, reading accumulated charge to produce a second set of imaging data; and generating image frames based on the first set of imaging data and the second set of imaging data.