Method of visible light and fluorescence imaging with reduced chromatic aberration

Patent metadata

Field	Value
Publication number	US-12575722-B2
Application number	US-202318326960-A
Country	US
Kind code	B2
Filing date	May 31, 2023
Priority date	Oct 23, 2017
Publication date	Mar 17, 2026
Grant date	Mar 17, 2026

Abstract

Improved fluoresced imaging (FI) endoscope devices and systems are provided to enhance use of endoscopes with FI and visible light capabilities. An endoscope device is provided for endoscopy imaging in a white light and a fluoresced light mode. A chromatic adjustment assembly, typically implemented with prisms, compensates for a chromatic focal difference between the white light image and the fluoresced light image caused by the dispersive properties of the optical materials or optical design employed in the construction of the optical channel. The assembly is placed optically between the most proximal rod lens of the endoscope and the focusing optics, typically at an internal telecentric image space, to improve the chromatic correction. The prism assembly directs incoming light with different spectral content along separate paths which compensate for chromatic aberration.

First claim

The invention claimed is:

1 . A method to collect in-focus images from an endoscopic optical device operable with white light and fluoresced light outside the visible band comprising the steps of
providing a visible light illuminating means; providing an excitation light illuminating means; providing an objective lens to collect a visible light spectrum image light and a fluorescence light spectrum image light; providing a plurality of relay lenses; providing an elongated shaft comprising a distal end and a proximal end, and containing the objective lens, and, proximally to the objective lens, the relay lenses; providing a chromatic adjustment assembly positioned proximally to a most proximal relay lens, wherein the chromatic adjustment assembly comprises a first beam splitter and a second beamsplitter; providing an image sensor positioned at an image plane; collecting a visible light image comprising the steps of:
illuminating an image scene with the visible illuminating means;
collecting visible image light in a spectrum comprising wavelengths between 400-700 nm from the illuminated image scene with the objective lens;
relaying the collected visible image light toward the chromatic adjustment system;
splitting, with the first beam splitter, the collected visible image light into a first image light spectrum and a second image light spectrum, where the first image light spectrum is different from the second image light spectrum;
directing the first image light along a first optical path;
directing the second image light along a second optical path, different from the first optical path;
recombining, with the second beam splitter, the first image light and the second image light; and
collecting, with the image sensor, a visible light image from the first image light and the second image light, where both first and second image lights are focused substantially onto the image plane; and
collecting a fluorescence imaging image comprising the steps of:
illuminating an image scene with the excitation illuminating means;
collecting fluorescence image light from the illuminated image scene with the objective lens;
relaying the collected fluorescence image light toward the chromatic adjustment system;
directing, by the first beamsplitter, the fluorescence image light along the second optical path;
directing, by the second beamsplitter, the fluorescence image light toward the image sensor; and
collecting, with the image sensor, a fluorescence imaging image from the fluorescence image light, and wherein the fluorescence image light is focused substantially onto the image plane.

2 . The method of claim 1 comprising the further steps of:
providing an image processing circuitry; and
processing the visible light image and the fluorescence imaging image with the image processing circuitry.

3 . The method of claim 2 wherein the step of processing the visible light image and the fluorescence imaging image comprises the step of combing the visible light image and the fluorescence imaging image.

4 . The method of claim 3 wherein the step of combining the images comprises the step of highlighting or emphasizing the fluorescence imagery for easily distinguishing the presence of fluorescing features in the combined image.

5 . The method of claim 1 , wherein the second image light spectrum is discontinuous.

6 . The method of claim 5 , wherein the first image light spectrum is continuous and consists of light with wavelengths longer than 450 nm and shorter than 750 nm.

7 . The method of claim 5 , wherein the second image light spectrum consists of wavelengths shorter than 450 nm and longer than 750 nm.

8 . The method of claim 1 , wherein the fluorescence image light is longer than 700 nm.

9 . The method of claim 1 , wherein the first and second image lights and the fluorescent image light collectively span from 400-900 nm.

10 . The method of claim 1 , further comprising the step of providing a field stop positioned between the most proximal relay lens and configured to prevent light from outside a designated field of view from propagating through the chromatic adjustment assembly.

11 . The method of claim 1 , further comprising the step of providing a field stop as an integral member of the chromatic adjustment assembly and configured to prevent light from outside a designated field of view from propagating downstream from the field stop.

Assignees

• Storz Karl Imaging Inc

Inventors

• Duckett Iii George E

Classifications

• G02B21/0032

  Optical details of illumination, e.g. light-sources, pinholes, beam splitters, slits, fibers (G02B21/0036 - G02B21/008; means for illumination of specimens in general G02B21/06) · CPC title

• A61B1/0019

  characterised by variable lenses · CPC title

• A61B1/0638

  providing two or more wavelengths · CPC title

• G02B21/0064

  multi-spectral or wavelength-selective arrangements, e.g. wavelength fan-out, chromatic profiling (G02B21/0076 takes precedence) · CPC title

• A61B1/0653

  with wavelength conversion · CPC title