Optical system for fluorescence observation

Patent metadata

Field	Value
Publication number	US-10054775-B2
Application number	US-201514940639-A
Country	US
Kind code	B2
Filing date	Nov 13, 2015
Priority date	Nov 13, 2014
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

An optical system for fluorescence observation comprises optics including an ocular 17 , a camera 55 , a display 69 , a light source 71 , an illumination light filter 84 , an observation light filter 57 and a controller 35 . The observation filter has multiple transmitting regions which allows light which was generated by a fluorescence to traverse for observation. The transmitting ranges are divided by blocking ranges. At the wavelength ranges at which the observation filter has a transmitting region the illumination filter has a blocking region and the other way round. The multiple transmitting regions of the illumination filter enable an improved color impression under normal light observation. The controller is configured to process a fluorescent light image obtained by the camera by identifying a contiguous fluorescent region in the fluorescent light image, generating an image including a representation of the boundary of the contiguous fluorescent region, and supplying the generated image to the display.

First claim

The invention claimed is:

1. An optical system for fluorescence observation, comprising:
optics including an ocular, a camera, a display, a light source, a first illumination light filter, a first observation light filter, and a controller;
wherein the optics provides a first beam path from the light source to an object region for illuminating the object region,
wherein the optics provides a second beam path from the object region to the ocular for imaging the object region via the ocular,
wherein the optics provides a third beam path from the object region to the camera for imaging the object region onto the camera, and
wherein the optics provides a fourth beam path from the display to the ocular for imaging an image, displayed by the display, via the ocular;
wherein the optical system has a first mode of operation, in which the first illumination light filter is arranged in the first beam path and the first observation light filter is arranged in the third beam path;
wherein the first observation light filter has, in a wavelength range from 380 nm to 725 nm, a transmission characteristics as follows:

at least two non-overlapping transmitting regions of the first observation light filter, each of the transmitting regions having, between a first wavelength and a second wavelength, a mean transmittance greater than a first value; and
plural blocking regions of the first observation light filter, the plural blocking regions including: a first blocking region of the first observation light filter having, between 380 nm and a smallest one of the first wavelengths of the at least two transmitting regions of the first observation light filter, a mean transmittance smaller than a second value, and at least one further blocking region of the first observation light filter, each of the further blocking regions having, between the second wavelength of one of the at least two transmitting regions of the observation light filter and the first wavelength of a further one of the at least two transmitting regions of the first observation light filter, a mean transmittance smaller than a third value;
wherein the first illumination light filter has, in a wavelength range from 380 nm to 725 nm, a transmission characteristics as follows:
plural transmitting regions of the first illumination light filter, the plural transmitting regions including:
a first transmitting region of the first illumination light filter having, between 380 nm and a wavelength smaller than the smallest one of the first wavelengths of the at least two transmitting regions of the first observation light filter, a mean transmittance greater than a fourth value, and
further transmitting regions of the first illumination light filter, each of the further transmitting regions having, between a wavelength greater than the second wavelength of a transmitting region of the first observation light filter and a wavelength smaller than the first wavelength of a further transmitting region of the observation light filter, a mean transmittance greater than a fifth value; and
plural blocking regions of the first illumination light filter, each of the blocking regions of the first illumination light filter having, between the wavelength smaller than the first wavelength of one of the transmitting regions of the first observation light filter and the wavelength greater than the second wavelength of this transmitting region of the first observation light filter, a mean transmittance smaller than a sixth value;
wherein the controller is configured to process a fluorescent light image obtained by the camera in the first mode of operation by identifying a contiguous fluorescent region in the fluorescent light image obtained in the first mode of operation based on at least one decision parameter, generating a representation of a boundary of the contiguous fluorescent region, generating an image including the representation of the boundary of the contiguous fluorescent region, and supplying the generated image to the display.

2. The optical system according to claim 1 , further comprising an input device for editing the at least one decision parameter.

3. The optical system according to claim 1 , wherein the optics further comprises a second illumination light filter and a second observation light filter; and
wherein the optical system has a second mode of operation, in which the second illumination light filter is arranged in the first beam path and the second observation light filter is arranged in the third beam path;
wherein the second illumination light filter has, in a wavelength range from 380 nm to 725 nm, a transmission characteristics as follows:
a transmitting region of the second illumination light filter having, between 380 nm and a first wavelength smaller than the smallest of the wavelengths of the at least two transmitting regions of the first observation light filter, a mean transmittance greater than the fourth value; and
a blocking region of the second illumination light filter having, between a second wavelength greater than the first wavelength and smaller than the smallest of the first wavelengths of the at least two transmitting regions of the first observation light filter and 725 nm, a mean transmittance smaller than the sixth value;
wherein the second observation light filter has, in the wavelength range from 380 nm to 725 nm, a transmission characteristics as follows:
a blocking region of the second observation light filter having, between 380 nm and the first wavelength, a mean transmittance smaller than the second value; and
a transmitting region of the second observation light filter having, between the second wavelength and 725 nm, a mean transmittance greater than the first value;
wherein the following formula is fulfilled in only one wavelength range:
T O2 (λ)· T I2 (λ)≥0.05

and wherein the following formula is fulfilled for all other wavelengths outside that wavelength range:
T O2 (λ)· T I2 (λ)<0.05

wherein the wavelength range extends between the first wavelength and the second wavelength, and the wavelength range extends over more than 50 nm, and
wherein T O2 (λ) is the transmittance of the second observation light filter in dependence of the wavelength and T I2 (λ) is the transmittance of the second illumination light filter in dependence of the wavelength.

4. The optical system according to claim 3 , wherein the camera is a color camera and the controller is configured
to switch the optical system from the first mode of operation to the second mode of operation;
to process a fluorescence image, obtained by the camera in the second mode of operation by identifying a boundary of a contiguous fluorescent region based on color information of the fluorescent light image obtained in the second mode of operation;
to switch the optical system from the second mode of operation to the first mode of operation,
to determine the at least one decision parameter such that the boundary of the fluorescent region identified in the fluorescent light image obtained in the first mode of operation substantially coincides with the boundary of the fluorescent region identified in the fluorescent light image obtained in the first mode of operation.

5. The optical system according to claim 3 , wherein the second observation light filter is arranged in the second beam path in the second mode of operation.

6. The optical system according to claim 3 , wherein the second illumination light filter and the second observation light filter are configured for excitation and detection of a fluorescence of Protoporphyrine IX.

7. The optical system according to claim 1 , wherein the first illumination light filter and the first observation light filter are configured for excitation and

Assignees

• Zeiss Carl Meditec Ag

Inventors

• Hauger Christoph
• Guckler Roland

Classifications

• G02B21/22

  Stereoscopic arrangements · CPC title

• G02B21/18

  Arrangements with more than one light path, e.g. for comparing two specimens · CPC title

• G02B21/16

  adapted for ultraviolet illumination {; Fluorescence microscopes (G02B21/0076 takes precedence)} · CPC title

• A61B5/0071

  by measuring fluorescence emission · CPC title

• G02B21/0012 Primary

  Surgical microscopes (counterbalanced structures for surgical microscopes G02B7/001) · CPC title