Patent ID: 12206968

DETAILED DESCRIPTION OF THE REPRESENTATIVE EMBODIMENTS

FIG.1shows a schematic illustration of an image capture system10for capturing an image of a medical object12in reemitted and/or reflected illumination light, for capturing an image of the medical object in fluorescence light emanating from protoporphyrin and for capturing an image in fluorescence light emanating from indocyanine green. The medical object12can be arranged within a cavity or on a surface of a body of a human or animal patient. Accordingly, the image capture system10can be arranged completely or partly within or completely outside of the body of a human or animal patient.

By way of example, the image capture system10can be an endoscope, an exoscope or a surgical microscope, or comprise an endoscope, an exoscope or a surgical microscope.

The observation of fluorescence light, in particular the observation of images in fluorescence light can facilitate or simplify a diagnosis. Protoporphyrin has a higher concentration in tumors than in healthy tissue, and so a distinction between healthy tissue and neoplasias can be made on the basis of the fluorescence of protoporphyrin. Indocyanine green has a higher concentration in vessels, and so the vascular system can be distinguished particularly well from surrounding tissue in the fluorescence light of indocyanine green.

The image capture system10comprises a light-source device20having a first light source21, a second light source22, a third light source23, a first dichroically reflecting surface24and a second dichroically reflecting surface25.FIG.1indicates that each of the light sources21,22,23comprises a light-emitting diode for generating light. Additionally or alternatively, each light source21,22,23can comprise one or more semiconductor lasers or other lasers, further light-emitting diodes or other light sources.

The first light source21is designed to generate broadband illumination light, the spectrum of which has components in the wavelength range perceived as blue by the healthy human eye, in the wavelength range perceived as green by the healthy human eye and in the wavelength range perceived as orange to red by the healthy human eye. To this end, the first light source21for example comprises one or more light-emitting diodes originally emitting in the wavelength range perceived as blue or violet by the healthy human eye, and a luminescence layer which absorbs some of the blue or violet light and emits light in the wavelength ranges perceived as red and green by the healthy human eye. Alternatively, the first light source21for example comprises a plurality of light-emitting diodes that each emit approximately in monochromatic fashion, i.e., with a narrow bandwidth at various wavelengths, and these together cover a range of wavelengths that is as large as possible between a lower boundary at approximately 400 nm to 430 nm and an upper boundary at approximately 700 nm to 750 nm.

The second light source22is provided and designed to emit narrowband first excitation light for exciting the fluorescence of protoporphyrin IX. To this end, the second light source22emits light that is as narrowband as possible and as intensive as possible, within the wavelength range of approximately 380 nm to approximately 450 nm, for example at approximately 405 nm, the absorption maximum of protoporphyrin IX.

The third light source23is provided and designed to emit narrowband second excitation light for exciting the fluorescence of indocyanine green. To this end, the third light source23emits light that is in particular as narrowband as possible and as intensive as possible, within the wavelength range between 700 nm and 850 nm, for example at approximately 800 nm, the absorption maximum of indocyanine green.

The first dichroically reflecting surface24completely reflects illumination light emitted by the first light source21, or reflects this light to the greatest possible extent, and completely transmits first excitation light emitted by the second light source22, or transmits this light to the greatest possible extent, such that the illumination light generated by the first light source21and the first excitation light generated by the second light source22are superposed as completely as possible. The second dichroically reflecting surface25completely reflects second excitation light emitted by the third light source23, or reflects this light to the greatest possible extent, and completely transmits illumination light generated by the first light source21and first excitation light generated by the second light source22, or transmits this light to the greatest possible extent, such that the illumination light generated by the first light source21, the first excitation light generated by the second light source22and the second excitation light generated by the third light source23are superposed as completely as possible. The light from the light sources21,22,23which has been superposed as completely as possible, i.e., combined, is coupled into an optical waveguide26and guided to the medical object12.

The dichroically reflecting surfaces24,25of the light-source device20represent examples of devices for superposing or combining the light generated by the light sources21,22,23. Alternatively, use can be made of polarization-dependently reflecting surfaces or other devices—especially if the light sources21,22,23generate polarized light.

The image capture system10further comprises an image capture apparatus30. The image capture apparatus30can be a camera or part of a camera. Alternatively, the image capture apparatus30can be an endoscope or an exoscope or a surgical microscope, or can be part of an endoscope or of an exoscope or of a surgical microscope. The image capture apparatus30comprises an objective40for imaging the medical object12, i.e., for generating a real image of the medical object12, and a beam splitter50with a dichroically reflecting surface51in an otherwise optically transparent prism. A first filter56in front of a first image sensor60and a second filter57in front of a second image sensor70are arranged downstream of the beam splitter50in the light path. The objective40generates real images of the medical object12in light-sensitive layers62,72of the image sensors60,70. By way of example, the light-sensitive layers62,72of the image sensors60,70are represented by surfaces of the image sensors60,70that face the beam splitter50.

The dichroically reflecting surface51of the beam splitter50causes an image of the medical object12in reemitted and/or reflected illumination light of the first light source21to arise in the light-sensitive layer62of the first image sensor60, said image being referred to as a color image below, and causes an image of the medical object12in fluorescence light emitted by the medical object12to arise in the light-sensitive layer72of the second image sensor70, said image being referred to as fluorescence image below. To this end, the dichroically reflecting surface51of the beam splitter50substantially completely and essentially exclusively reflects light with wavelengths that are shorter than a threshold wavelength λ0, and substantially completely and essentially exclusively transmits light with wavelengths that are longer than the threshold wavelength λ0. The threshold wavelength λ0ranges between 600 nm and 640 nm, in particular is located at 620 nm or 630 nm. As a result, some of the light reemitted and/or reflected by the medical object12within the light perceived as orange or red by the healthy human eye is incident on the first image sensor60and is captured in the latter's red color channel Therefore, a substantially normal or natural color impression can be generated using only the color image captured by the first image sensor60.

Both fluorescence light generated by protoporphyrin IX in the medical object12and fluorescence light generated by indocyanine green in the medical object12are captured by the second image sensor70. The second image sensor70can be a monochromatic image sensor, i.e., have only one color channel. Alternatively, the second image sensor70can have a plurality of color channels, one of which exclusively or substantially exclusively captures the fluorescence of protoporphyrin IX and another one of which exclusively or substantially exclusively captures the fluorescence of indocyanine green.

The first filter56between the beam splitter50and the first image sensor60suppresses first excitation light, which is generated by the second light source22and reemitted and/or reflected by the medical object12without a wavelength change, in order to avoid a blue tint of the color image captured by the first image sensor60. To this end, the first filter56particularly suppresses light with a wavelength shorter than a further threshold wavelength λ1. The further threshold wavelength λ1ranges between 410 nm and 440 nm in particular, preferably at approximately 430 nm.

To also capture the reemission and reflection properties of the medical object12at wavelengths shorter than the further threshold wavelength λ1, the first filter56can be formed in front of the first image sensor60such that some of the first excitation light, which is generated by the second light source22and reemitted by the medical object12, can reach the first image sensor60and can contribute to generating the color image in the light-sensitive layer62of the first image sensor60.

The second filter57in front of the second image sensor70is provided and designed to suppress second excitation light, which is generated by the third light source23and reemitted by the medical object12. To this end, the second filter57suppresses, in particular, light in a wavelength range with a lower limit at 700 nm to 790 nm and an upper limit at 810 nm to 850 nm, said wavelength range being as narrow as possible and including, as completely as possible, the spectrum of the second excitation light generated by the third light source23.

The second filter57can be designed to suppress the light, which is generated by the third light source23and reemitted and/or reflected by the medical object12, only extensively but not completely. Hence, the reemission and reflection properties of the medical object12at the wavelengths suppressed by the second filter57can also contribute to generate the color image in the light-sensitive layer72of the second image sensor70.

At an image signal output68, the first image sensor60provides a first image signal which represents the color image captured by the first image sensor60. At an image signal output78, the second image sensor70provides a second image signal which represents the fluorescence image captured by the second image sensor70.

The image capture system10further comprises a camera control unit (CCU)80with a first control output81, which is coupled to the first light source21, a second control output82, which is coupled to the second light source22, a third control output83, which is coupled to the third light source23, a first image signal input86, which is coupled to the image signal output68of the first image sensor60, a second image signal input87, which is coupled to the image signal output78of the second image sensor70, and an image signal output88. The camera control unit80controls the light sources21,22,23of the light-source device20and the image sensors60,70, receives and processes the image signals provided by the image sensors60,70and provides at an image signal output88an image signal containing information from both image signals provided by the image sensors60,70.

In particular, the image signal provided at the image signal output88by the camera control unit80represents a color image of the medical object in which vessels recognizable on the basis of the fluorescence of protoporphyrin IX and/or tumor tissue recognizable on the basis of the fluorescence of indocyanine green are emphasized. The emphasis can be implemented in each case by way of color, intensity, or time-dependent modulation, for example.

In particular, the camera control unit80controls one of the methods illustrated on the basis ofFIGS.4,5and6.

FIG.2shows a schematic representation of the emission spectra of the light sources21,22,23. The wavelength λ in nm is assigned to the abscissa while the intensity I in arbitrary or relative units is assigned to the ordinate.

The spectrum91of the first light source21(cf.FIG.1) or of the illumination light provided by the first light source21, represented by a solid line, substantially comprises wavelengths between 430 nm and 730 nm and is substantially constant, i.e., wavelength independent, within these limits in the illustrated example.

The spectrum92of the second light source22or of the first excitation light provided by the second light source22, represented by a line with short dashes, is narrowband. In the illustrated example, the spectrum92of the second light source22has a maximum at 400 nm to 410 nm and comprises only or substantially only wavelengths shorter than 430 nm.

The spectrum93of the third light source23, i.e., of the second excitation light generated by the third light source23, represented by a line with longer dashes, is narrowband. In the illustrated example, the spectrum93of the third light source has a maximum at approximately 800 nm and comprises only or substantially only wavelengths longer than 730 nm.

FIG.3shows a schematic representation of the transmission characteristics of the dichroic surface51of the beam splitter50, and of the filters56,57(cf.FIG.1). The wavelength λ in nm is assigned to the abscissa while the transmission T is assigned to the ordinate.

The transmission95of the dichroically reflecting surface51of the beam splitter50, represented by a full line, is low at wavelengths shorter than a threshold wavelength λ0of approximately 630 nm, i.e., substantially 0, and high at wavelengths longer than the threshold wavelength λ0of 630 nm, that is substantially 1=100%. The reflection R, not illustrated, complements the transmission95, i.e., it is approximately R=1−T.

The transmission96of the first filter56, illustrated by a line with short dashes, is low, but not 0, at wavelengths shorter than 430 nm in order to allow some of the first excitation light, which was emitted by the second light source22and reemitted and/or reflected by the medical object12, to reach the first image sensor60. The transmission96of the first filter56is high, in particular approximately 1=100%, at wavelengths between 430 nm and 630 nm. In the illustrated example, the transmission96of the first filter56is small, in particular substantially 0, at wavelengths longer than 630 nm.

Deviating from the illustration inFIG.3, the transmission96of the first filter56can be significant, in particular be substantially 1=100%, even at wavelengths greater than 630 nm. In this case and deviating from the illustration inFIG.1, the first filter56can be arranged in front of the beam splitter50, i.e., upstream of the beam splitter50in the light path.

The transmission97of the second filter57in front of the second image sensor70, illustrated by a line with longer dashes, is low, in particular substantially 0, in a wavelength range between 730 nm and 810 nm in order to completely or substantially completely suppress second excitation light, which is generated by the third light source23and reemitted and/or reflected by the medical object12. The transmission97of the second filter57is high, in particular substantially 1=100%, at wavelengths longer than 810 nm and between 630 nm and 730 nm. In the illustrated example, the transmission97of the second filter57is low, in particular substantially 0, at wavelengths shorter than 630 nm.

Alternatively and deviating from the illustration inFIG.3, the transmission97of the second filter57can be high even at wavelengths shorter than 630 nm. In this case, the second filter57can be arranged in front of the beam splitter50.

Deviating from the illustration inFIG.1, instead of having two filters56,57after the beam splitter50, i.e., downstream of the beam splitter50in the light path and hence between the beam splitter50and the image sensors60,70, both filters56,57can be arranged in front of the beam splitter50, i.e., upstream of the beam splitter50in the light path. Alternatively, provision can be made for a single filter in front of the beam splitter50, i.e., upstream of the beam splitter50in the light path. In a manner similar to what is indicated inFIG.3, this only filter substantially but not completely (or deviating from the illustration inFIG.3: completely) suppressed first excitation light, which is generated by the second light source22and reemitted and/or reflected by the medical object12, with wavelengths shorter than 430 nm, suppressed second excitation light (cf. spectrum93inFIG.2), which is generated by the third light source23and reemitted and/or reflected by the medical object12, in the wavelength range from 730 nm to 810 nm and completely or substantially completely transmitted both light between 430 nm and 730 nm and light with wavelengths longer than 810 nm.

Both the spectra91,92,93of the light sources21,22,23and the transmission spectra95,96,97can be slightly shifted in relation to the wavelengths illustrated on the basis ofFIGS.2and3. However, in this case the spectra92,93of the second light source22and of the third light source23should be chosen such that the fluorescence of protoporphyrin IX and the fluorescence of indocyanine green are excited as efficiently as possible and with the narrowest possible bandwidth. Further, the transmission spectrum95and the complementary reflection spectrum of the beam splitter50should be chosen such that as much as possible of the illumination light generated by the first light source21but as little as possible of the fluorescence light generated by protoporphyrin IX or indocyanine green, in particular no fluorescence light at all, is incident on the first image sensor60. Further, the transmission spectra96,97of the filters56,57or of an alternative single filter in front of the beam splitter50should be chosen such that first excitation light, which is generated by the second light source22and reemitted and/or reflected by the medical object12, falsifies the color impression in the color image captured by the first image sensor60as little as possible and second excitation light, which is generated by the third light source23and reemitted and/or reflected by the medical object12, is incident to the smallest possible extent on the second image sensor70.

As an alternative to the spectra illustrated on the basis ofFIG.2, the spectrum91of the illumination light provided by the first light source21can have a lower intensity or a much lower intensity or even a vanishing intensity at wavelengths longer than the threshold wavelength λ0. In this case, the second image sensor70only receives correspondingly little or no reemitted and/or reflected illumination light, but predominantly or exclusively fluorescence light.

FIG.4shows a schematic flowchart of a method for capturing an image of a medical object12in reemitted and/or reflected illumination light, for capturing an image of the medical object12in fluorescence light generated by protoporphyrin IX and for capturing an image of the medical object in fluorescence light generated by indocyanine green. In particular, the method can be carried out using the image capture system10illustrated on the basis ofFIGS.1to3and under control of the camera control unit80of the image capture system10, but alternatively it can also be carried out by a system with features, properties and functions that deviate from the image capture system illustrated on the basis ofFIGS.1to3. Reference signs fromFIGS.1to3are used in exemplary fashion.

In a method step101, the medical object12is irradiated by illumination light with a broad spectrum91, which comprises components in the wavelength ranges perceived as blue, green, and orange to red by the healthy human eye. In a further method step102, which is carried out at the same time, the medical object12is irradiated by first excitation light for the purposes of exciting the fluorescence of protoporphyrin IX. In a further method step103, which is carried out at the same time, the medical object12is irradiated by second excitation light for the purposes of exciting the fluorescence of indocyanine green. In a further method step106, which is carried out at the same time, a first image sensor60is used to capture a color image in reemitted and/or reflected illumination light in the spectral ranges perceived as blue, green, and orange to red by the healthy human eye. In a further method step107, which is carried out at the same time, a second image sensor70is used to capture an image of the medical object12, which is referred to as fluorescence image, in fluorescence light generated by protoporphyrin IX and/or in fluorescence light generated by indocyanine green. The fluorescence of protoporphyrin IX and the fluorescence of indocyanine green can be captured together in a monochrome fluorescence image or can be captured in two different color channels of a fluorescence image.

An image signal containing both information from the color image and information from the fluorescence image is generated in a further method step111.

In a further method step112, an image is displayed under control of the image signal generated in method step111, said display being implemented, for example, by one or more monitors, a projector and/or virtual reality or augmented reality goggles.

Deviating from the illustration inFIG.4, the broadband illumination light and the first excitation light and the second excitation light need not be generated at the same time and the color image and the fluorescence image need not be captured at the same time. Especially if the fluorescence image is captured by a monochrome image sensor70which has only one color channel in which both the fluorescence of protoporphyrin IX and the fluorescence of indocyanine green are captured, only partial simultaneity may be advantageous in order to distinguish the fluorescence of protoporphyrin IX and the fluorescence of indocyanine green. An only partial simultaneity deviating from the illustration inFIG.4can further facilitate a correction of the image signal in the red color channel and hence a better color reproduction. Examples of such modified methods are shown inFIGS.5and6.

FIG.5shows a schematic illustration of a flowchart of a further method for capturing an image of a medical object in reemitted and/or reflected broadband illumination light, for capturing an image of the medical object in fluorescence light generated by protoporphyrin IX and for capturing an image of the medical object12in fluorescence light generated by indocyanine green.

The method shown inFIG.5differs from the method illustrated on the basis ofFIG.4in that, initially, only the irradiation101with illumination light, the irradiation102with first excitation light, the capture106of a color image and the capture107of a first fluorescence image (specifically in fluorescence light generated by protoporphyrin IX) occur simultaneously during a first time interval, but not the irradiation with the second excitation light. Only in a subsequent, non-overlapping second time interval are the irradiation101with broadband illumination light, the irradiation103with second excitation light, the capture106of a color image and a capture108of a second fluorescence image (specifically in fluorescence light generated by indocyanine green) implemented simultaneously, but not the irradiation with first excitation light. In this way, it is possible to distinguish between the fluorescence of protoporphyrin IX and the fluorescence of indocyanine green, and in the image signal generated in subsequent steps111,112and in the displayed image controlled thereby it is possible to characterize or mark or emphasize the fluorescence of protoporphyrin IX and the fluorescence of indocyanine green differently.

In an alternative deviating fromFIG.5, only steps101,102,106,107and, subsequently, steps111,112are carried out, as a result of which an image of the medical object12in reemitted and/or reflected illumination light and an image of the medical object12in fluorescence light generated by protoporphyrin IX are captured, but no image of the medical object12is captured in fluorescence light generated by indocyanine green. In a further alternative deviating fromFIG.5, only steps101,103,106,108and, subsequently, steps111,112are carried out, as a result of which an image of the medical object12in reemitted and/or reflected illumination light and an image of the medical object12in fluorescence light generated by indocyanine green are captured, but no image of the medical object12is captured in fluorescence light generated by protoporphyrin IX.

FIG.6shows a schematic flowchart of a further method for capturing an image of a medical object in reemitted and/or reflected broadband illumination light, for capturing an image of the medical object in fluorescence light generated by protoporphyrin IX and for capturing an image of the medical object in fluorescence light generated by indocyanine green.

The method shown inFIG.6differs from the method illustrated on the basis ofFIG.5in that, in particular, the medical object12is irradiated by red light, i.e. light in the wavelength range perceived as red by the healthy human eye and, at the same time, a red light image in reemitted and/or reflected red light is captured by means of the second image sensor in a third time interval, without the medical object12being irradiated by first excitation light or by second excitation light at the same time. As a result, only the red light reemitted and/or reflected by the medical object12, and not fluorescence, is captured in a method step109—by the second image sensor70in the image capture system illustrated on the basis ofFIGS.1to3. In a subsequent step110, the red light image can be used to correct the red color channel of the color image and hence can be used to improve the color reproduction. Instead of an irradiation with red light, i.e., with light that only has spectral components in the wavelength range perceived as red by the healthy human eye, it is possible to use light containing further wavelength ranges, for example broadband illumination light as used in step101. In this case, the medical object12can be irradiated continuously by the broadband illumination light with components in the wavelength ranges perceived as blue, green, and red by the healthy human eye.

In the method shown inFIG.6, capture of a first fluorescence image and capture of a second fluorescence image are envisaged in two different and non-overlapping time intervals, similar to the method illustrated on the basis ofFIG.5. Alternatively, like in the method illustrated on the basis ofFIG.4, the fluorescence of protoporphyrin IX and the fluorescence of indocyanine green can be captured simultaneously.

In each of the methods illustrated on the basis ofFIGS.4to6, the second image sensor70can receive and capture both reemitted and/or reflected illumination light and fluorescence light generated by protoporphyrin IX and/or by indocyanine green within the wavelength range between the threshold wavelength λ0and approximately 730 nm in method steps107,108. If the medical object12is irradiated continuously by illumination light generated by the first light source21, it is possible to obtain a pure fluorescence image as a difference between an image captured by the second image sensor during the illumination with both illumination light and excitation light, and an image captured during the illumination with illumination light only.

If the medical object12is not irradiated continuously by illumination light generated by the first light source21, it is possible to capture a pure fluorescence image while the medical object12is only illuminated by excitation light.

As indicated above, the intensity of the illumination light generated by the first light source21—deviating from the illustration inFIG.2—can be small or even vanishing at wavelengths longer than the threshold wavelength λ0. In this case, even if the first light source21generates illumination light continuously, the second image sensor70receives little or no illumination light, which is generated by the first light source21and reemitted and/or reflected by the medical object12. Rather, most or all of the light received by the second image sensor70is fluorescence light and the image captured by the second image sensor70is a pure or almost pure fluorescence image.

If the illumination light generated by the first light source21only has a low intensity or vanishing intensity at wavelengths above the threshold wavelength λ0, the methods described on the basis ofFIGS.4to6can be particularly advantageous. A fourth light source for generating light in the wavelength range above the threshold wavelength λ0perceived as red by the healthy human eye is in particular further provided in this case in the method described on the basis ofFIG.6, in order to illuminate the medical object12in this wavelength range within the scope of method step104.

FIG.7shows a schematic flowchart of a further method for capturing an image of a medical object in reemitted or reflected broadband illumination light, for capturing an image of the medical object in fluorescence light generated by protoporphyrin IX and for capturing an image of the medical object in fluorescence light generated by indocyanine green.

The method shown inFIG.7differs from the method illustrated on the basis ofFIG.6in terms of the first time interval, in particular. During the first time interval, the medical object12is irradiated102merely by first excitation light, but not by illumination light. During the first time interval, the second image sensor70simultaneously captures107a first fluorescence image in fluorescence light generated by protoporphyrin IX, like in the methods illustrated on the basis ofFIGS.4to6. In contrast to the methods illustrated on the basis ofFIGS.4to6, no color image is captured in the first time interval. However, a blue-light image in reemitted and/or reflected first excitation light is captured119by the blue color channel of the first image sensor60during the first time interval, simultaneously with the irradiation102with first excitation light.

In the second time interval, the method shown inFIG.7is similar to the methods shown inFIGS.5and6.

In a later method step120, the blue color channel of the color image captured during the second time interval is corrected, in particular by adding the blue-light image captured during the first time interval. This correction can add the diffuse and specular reflection properties of the medical object12to the color image at wavelengths shorter than 430 nm and hence improve the color reproduction.

The method described on the basis ofFIG.7can be carried out both with a first light source21which only generates a low or vanishing intensity above the threshold wavelength λ0and with a first light source21which generates a substantial intensity above the threshold wavelength λ0(as shown inFIG.2).

FIG.8shows a schematic flowchart of a further method for capturing an image of a medical object in reemitted and/or reflected broadband illumination light, for capturing an image of the medical object in fluorescence light generated by protoporphyrin IX and for capturing an image of the medical object in fluorescence light generated by indocyanine green.

The method shown inFIG.8differs from the methods illustrated on the basis ofFIGS.4to7in that, in particular, the capture106of the color image, the capture107of the first fluorescence image and the capture108of the second fluorescence image is implemented in three different and non-overlapping time intervals.

In a first time interval, the medical object12is irradiated101by illumination light and a color image is captured at the same time by means of the first image sensor60. If the illumination light in the wavelength range captured by the second image sensor70has a substantial intensity, a red light image can be captured simultaneously by means of the second image sensor70in an optional method step109. This red light image can be used in a subsequent method step110for correcting the red color channel of the color image captured by means of the first image sensor60.

In a second time interval, the medical object12is irradiated102by first excitation light and a first fluorescence image in fluorescence light generated by protoporphyrin IX is captured at the same time by means of the second image sensor70. If the blue color channel of the first image sensor60receives first excitation light reemitted and/or reflected by the medical object12, a blue-light image in remitted and/or reflected first excitation light can be captured simultaneously by means of the first image sensor60in an optional method step119. This blue-light image can be used in a subsequent method step120for correcting the blue color channel of the color image captured by means of the first image sensor60.

In a third time interval, the medical object12is irradiated103by second excitation light and a second fluorescence image in fluorescence light generated by indocyanine green is captured108at the same time by means of the second image sensor70.

An image capture system10as described on the basis ofFIGS.1to3can have a plurality of different modes of operation, in which the methods described on the basis ofFIGS.4to8, parts of these methods and/or further methods are carried out. In particular, each of the methods described on the basis ofFIGS.5and6can be modified by virtue of dispensing with either the method steps101,102,106,107carried out in the first time interval or the method steps101,103,106,108carried out in the second time interval. Further, the image capture system10can have one or more modes of operation, within the scope of which only a white-light image is captured and/or only a white-light image without fluorescence information is displayed. Further, the image capture system10can have one or more modes of operation, within the scope of which only a fluorescence image is captured and/or only a fluorescence image without white-light image information is displayed.

Although the invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope of the invention as defined by the appended claims. The combinations of features described herein should not be interpreted to be limiting, and the features herein may be used in any working combination or sub-combination according to the invention. This description should therefore be interpreted as providing written support, under U.S. patent law and any relevant foreign patent laws, for any working combination or some sub-combination of the features herein. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.