Tissue fluorescence monitor with ambient light rejection

Patent metadata

Field	Value
Publication number	US-10045696-B2
Application number	US-201313946363-A
Country	US
Kind code	B2
Filing date	Jul 19, 2013
Priority date	Jul 19, 2013
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

Fluorescent markers used to identify a tissue may be imaged in a bright environment by synchronizing the imaging process with rapidly switched ambient lighting so that imaging occurs in phase with a switching off of the ambient lighting. In this way, valuable fluorescent imaging may be performed in an environment that appears to be brightly illuminated, for example in the area of a surgical suite.

First claim

What we claim is:

1. A medical imaging system for tissue imaging in a surgical suite comprising:
a communication channel;
multiple area illuminators switching between an on-state, providing area illumination light, and an off-state, not providing area illumination light, in accordance with a timing signal providing that the multiple area illuminators are in the off-state for a majority of a time between successive initiations of the on-state and received over the communication channel, the area illuminators sized and positioned to illuminate an operating room table during surgery at a level allowing direct viewing by a physician of a patient's tissue during surgery;
a computer monitor having a source of illumination switching between an on-state providing display illumination and an off-state, not providing display illumination, in accordance with the timing signal providing that the display illumination is in the off-state for a majority of a time between successive initiations of the on-state and received over the communication channel, the computer monitor sized to be positioned with respect the operating room table at the level allowing direct viewing by the physician of the computer monitor during surgery;
an exciting light source having a frequency adapted to excite fluorescence in the patient's tissue;
an imager imaging fluorescence from the patient's tissue as stimulated by the exciting light source to produce a fluorescence image; and
a synchronization circuit communicating with the imager, the computer monitor, and the area illuminators over the communication channel to produce a fluorescence image by synchronizing the imager with switching of the area illuminators and the light source of the computer monitor, between the on-state and the off-state so that the imager is switched to an inactive-state with respect to generating the fluorescence image when the area illuminators and the light source of the computer monitor are in the on-state and the imager is switched to an active-state with respect to generating the fluorescence image when the area illuminators and the light source of the computer monitor are in the off-state and so that the imager is in the active-state for a majority of a capture cycle of one on-state and one off-state;
wherein a frequency of the switching of the area illuminators is above 24 hertz.

2. The medical imaging system of claim 1 wherein the imager includes an image intensifier.

3. The medical imaging system of claim 1 wherein the synchronization circuit outputs a synchronization signal receivable by multiple area illuminators indicating a desired timing of the on-state and the off-state of the multiple area illuminators.

4. The medical imaging system of claim 1 wherein the synchronization circuit receives a synchronization signal from at least one area illuminator indicating a timing of the on-state and the off-state of the area illuminator and wherein the synchronization circuit controls the imager to match the timing of the on-state and the off-state of the area illuminator.

5. The medical imaging system of claim 1 wherein the imager operating in the inactive-state preserves acquired image frames with respect to an area illumination image and further including a compositing circuit generating an image from a combination of the fluorescence image and the area illumination image.

6. The medical imaging system of claim 1 wherein the light element is at least one light emitting diode.

7. The medical imaging system of claim 1 wherein further including an illuminated sign having a source of illumination switching between an on-state providing sign illumination and an off-state, not providing sign illumination, in accordance with the timing signal providing that the sign illumination is in the off-state for a majority of a time between successive initiations of the on-state and received over the communication channel;
wherein the synchronization circuit further communicates with the illuminated sign over the communication channel to produce a fluorescence image by synchronizing the imager with switching of the illuminated sign between the on-state and the off-state so that the imager is switched to an inactive-state with respect to generating the fluorescence image when the illuminated sign is in the on-state and the imager is switched to an active-state with respect to generating the fluorescence image when illuminated sign is in the off-state.

8. The medical imaging system of claim 1 wherein the imager further images the patient's tissue as illuminated by the area illuminators when operating in the inactive-state to produce an area illumination image and further including a compositing circuit generating an image from a combination of the fluorescence image and the area illumination image.

9. The medical imaging system of claim 1 further including an area light imager imaging area light reflected by the patient's tissue from the area illumination light and further including a compositing circuit generating an image from a combination of the fluorescence image from the imager and an area light image from the area light imager.

10. The medical imaging system of claim 1 wherein the imager operates at a frame rate to acquire multiple image frames during a capture cycle of one on-state and one off-state during the active-state and inactive-state and wherein image frames acquired during the inactive-state are not used in the fluorescent image.

Assignees

• Wisconsin Alumni Res Found

Inventors

• Mackie Thomas
• Uselmann Adam
• Velten Andreas
• Prajapati Surendra
• Eliceiri Kevin

Classifications

• A61B5/0068

  Confocal scanning · CPC title

• A61B5/0062

  Arrangements for scanning · CPC title

• G01N21/6428

  Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53) · CPC title

• A61B1/043

  for fluorescence imaging · CPC title

• A61B5/0071 Primary

  by measuring fluorescence emission · CPC title