Illumination filter for an illumination filter system of a surgical multispectral fluorescence microscope having a spatial filter pattern
The invention relates to an illumination filter ( 36, 44 ) for an illumination filter system ( 2 ) for medical imaging, in particular multispectral fluorescence imaging, as performed e.g. in a microscope ( 1 ) or endoscope, in particular a multispectral fluorescence microscope. The present invention provides an illumination filter for medical imaging, in particular a multispectral fluorescence imaging, that is capable of capturing simultaneously more than one fluorescence signal, and allow a homogeneous illumination for obtaining different images from the object illuminated by comprising a spatial filter pattern ( 43 ) masking a defined filtering fraction of a first illumination path ( 47 ) on the filter and masking a defined filtering fraction of a second illumination path ( 48, 49, 50 ) on the filter, wherein the filtering fraction of the first and the second illumination paths ( 47, 48, 49, 50 ) are different. The invention further relates to an illumination filter system ( 2 ) for medical imaging, in particular multispectral fluorescence imaging, as performed e.g. in a microscope ( 1 ) or endoscope, in particular a multispectral fluorescence microscope, comprising such illumination filter ( 36, 44 ).
1. An illumination filter ( 36 , 44 ) for an illumination filter system ( 2 ) for medical imaging ( 1 ), in particular multispectral fluorescence imaging, comprising a spatial filter pattern ( 43 ) masking a defined filtering fraction of a first illumination path ( 47 ) on the filter and masking a defined filtering fraction of a second illumination path ( 48 , 49 , 50 ) on the filter, wherein the filtering fraction of the first and the second illumination paths ( 47 , 48 , 49 , 50 ) are different, wherein the spatial filter pattern ( 43 ) comprises a plurality of filter patches ( 51 ), and wherein respective centers ( 53 ) of adjacent filter patches ( 51 ) are essentially spaced equidistantly and respective areas (A) of the filter patches ( 51 ) vary.
2. The illumination filter ( 36 , 44 ) of claim 1 , wherein a filter coating ( 42 ) is applied as the spatial filter pattern ( 43 ) on a substrate ( 41 ), said coating ( 42 ) defining the filtering fraction of the first and the second illumination paths ( 47 , 48 , 49 , 50 ) on the substrate ( 41 ).
3. The illumination filter ( 36 , 44 ) of claim 2 , wherein the spatial filter pattern ( 43 ) is a band-stop filter pattern ( 43 a ) or a band-pass filter pattern ( 43 b ).
4. The illumination filter ( 36 , 44 ) of claim 3 , wherein a band-stop filter coating ( 42 ) or a band-pass filter coating ( 46 ) is applied as the spatial filter pattern ( 43 ) on the substrate ( 41 ).
5. The illumination filter ( 36 , 44 ) of claim 1 , wherein the spatial filter pattern ( 43 ) extends over a plurality of illumination paths ( 47 - 50 ) and the filtering fraction is different in each illumination path ( 47 - 50 ).
6. The illumination filter ( 36 , 44 ) of claim 5 , wherein the plurality of illumination paths ( 47 - 50 ) is arranged along an axis of the illumination filter ( 36 , 44 ).
7. An illumination filter ( 36 , 44 ) for an illumination filter system ( 2 ) for medical imaging ( 1 ), in particular multispectral fluorescence imaging, comprising a spatial filter pattern ( 43 ) masking a defined filtering fraction of a first illumination path ( 47 ) on the filter and masking a defined filtering fraction of a second illumination path ( 48 , 49 , 50 ) on the filter, wherein the filtering fraction of the first and the second illumination paths ( 47 , 48 , 49 , 50 ) are different, wherein the spatial filter pattern ( 43 ) comprises a plurality of filter patches ( 51 ), and wherein the filter patches ( 51 ) are filter squares ( 52 ).
8. The illumination filter ( 36 , 44 ) of claim 7 , wherein respective diagonal lengths ( 1 ) of the filter squares ( 52 ) varies in different illumination paths ( 47 - 50 ).
9. The illumination filter ( 36 , 44 ) of claim 8 , wherein the diagonal length ( 1 ) of the filter squares ( 52 ) varies along an axis of the illumination filter ( 36 , 44 ).
10. An illumination filter system ( 2 ) for a microscope ( 1 ), in particular a multispectral fluorescence microscope, comprising an illumination filter ( 36 , 44 ) having a spatial filter pattern ( 43 ) masking a defined filtering fraction of a first illumination path ( 47 ) on the filter and masking a defined filtering fraction of a second illumination path ( 48 , 49 , 50 ) on the filter, wherein the filtering fraction of the first and the second illumination paths ( 47 , 48 , 49 , 50 ) are different, wherein the spatial filter pattern ( 43 ) comprises a plurality of filter patches ( 51 ), and wherein respective centers ( 53 ) of adjacent filter patches ( 51 ) are essentially spaced equidistantly and respective areas (A) of the filter patches ( 51 ) vary.
11. The illumination filter system ( 2 ) of claim 10 , wherein the illumination filter ( 36 , 44 ) is configured to be moved from a first operation position ( 37 ), in which the first illumination path ( 47 ) is in optical communication with a light source ( 4 ), to a second operation position ( 38 ), in which the second illumination path ( 48 - 50 ) is in optical communication with a light source ( 4 ).
12. The illumination filter system ( 2 ) of claim 10 , comprising a first illumination filter ( 36 ) having a spatial band-stop filter pattern ( 43 a ) and a second illumination filter ( 44 ) having a spatial band-pass filter pattern ( 43 b ), wherein each of the first and second illumination filters ( 36 , 44 ) is configured to be moved from a first operation position ( 37 ), in which the first illumination path ( 47 ) is in optical communication with a light source ( 4 ), to a second operation position ( 38 ), in which the second illumination path ( 48 - 50 ) is in optical communication with a light source ( 4 ).
13. The illumination filter system ( 2 ) of claim 10 , further comprising a blocking filter ( 35 ) adapted to quench light of a fluorescence emission band (Em. 1 , Em. 2 ).
14. An illumination filter system ( 2 ) for a microscope ( 1 ), in particular a multispectral fluorescence microscope, comprising an illumination filter ( 36 , 44 ) having a spatial filter pattern ( 43 ) masking a defined filtering fraction of a first illumination path ( 47 ) on the filter and masking a defined filtering fraction of a second illumination path ( 48 , 49 , 50 ) on the filter, wherein the filtering fraction of the first and the second illumination paths ( 47 , 48 , 49 , 50 ) are different, wherein the spatial filter pattern ( 43 ) comprises a plurality of filter patches ( 51 ), and wherein the filter patches ( 51 ) are filter squares ( 52 ).