Embodiments
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
The microscope of the invention may be any light microscope which is suitable for polarization microscopy. An important aspect on which the invention is based is the presence of two linear polarizers in a first and a second optical path of the microscope.
The positions of the linear polarizers in the first and second optical paths are illustrated in Figure 2. Herein, both optical paths 7 and 8 follow a light beam depicted by a dashed line, running in the z direction. The first optical path 7 is defined as running from the illumination device 2 to the sample inspection area 6. The second optical path 8 runs from the sample inspection area 6, to said viewing arrangement 5.
A first linear polarizer 3 is positioned in said first optical path 7. Said first linear polarizer 3 has a transmission axis 6TAi and allows passing through light having polarization angle θι. The transmission axis ΘΤΑ1 and polarization angle θι are schematically indicated in figure 2 with an arrow. In the example of figure 2, the transmission angle is vertically orientated (thus in y direction of the illustration, 90 degrees from x), but it may be in any orientation. An unpolarized light beam from illumination device 2, after passing said first linear polarizer 3, will become linearly polarized at the same angle as the transmission axis 0TA1. A second linear polarizer 4 is positioned in said second optical path 8. By adjusting the difference in transmission angle between 0TAiand 0TA2, the amount of light having polarization angle θ! can be adjusted.
Figure 1 shows how this works. Suppose the second linear polarizer 4, whose transmission axis makes an angle θ with that of the first linear polarizer 3. The E vector of the light between the two polarizers 3 and
5 4 can be resolved into two components, one parallel and one perpendicular to the transmission axis of the second linear polarizer. If we call the direction of transmission of the second linear polarizer y',
E.r< = E stuff and E„. = Ecosff
Only the second, / component is transmitted by the second linear polarizer 4. The intensity of light is proportional to the square of the electric field amplitude. Thus the intensity transmitted by both linear 10 polarizers 3 and 4 can be expressed as:
I (ff) = Ep = E2 Θ
If Λ, = E~2 js ι-^θ intensity between the two polarizers 3 and 4, the intensity transmitted by both of them would be:
ƒ ($ ϊ = eos“ d
15 This equation applies to any two polarizing elements whose transmission axes make an angle θ with each other. When the two linear polarizers 3 and 4 are placed in succession in a beam of light as described here, the transmission is zero when the transmission axes 0TA1and 0TA2are crossed.
Said first optical path 7 and said second optical path 8 can be in any orientation towards each other. In figure 2, they are in each other's extension, and in figure 3 they are at an angle a.
20 It is essential that said first transmission axis θΤΑ1 and/or said second transmission axis 0TA2 can be adjusted with respect to said inspection area 6 and do/does not require rotation of a sample present in said inspection area 6. This may be effectuated by various means. For instance, one or both of the linear polarizers 3 and 4 can be provided with rotation means. As shown in figure 2, the first linear polarizer 3 is rotatable, thereby adjusting the first transmission axis ΘΤΑ1 vis-a-vis the sample inspection area 6. In
25 the embodiment shown in figure 5 and 6, both linear polarizers 3 and 4 are positioned in a rotatable disk 19. By rotating this disk 19, the first transmission axis 6TA1and said second transmission axis θτΑ2 are adjusted in unison.
In another embodiment, said first transmission axis ΘΤΑ1 can be adjusted using a rotatable beam splitter. Said microscope comprises an assembly (indicated in figure 7 with a dashed box) comprising a beam splitter 11, said first polarizer 3, and illumination device 2, wherein said assembly is rotatably mounted around said second optical axis 8. Said assembly may be connected with each other by a rotatable mounting means. By rotating said mounting means, the polarization angle of said first polarizer 3 towards said sample inspection area 6 can be adjusted.
In another embodiment, as illustrated in figures 8 and 9, said first transmission axis θΤΑι can be adjusted using a rotatable illumination device. Said microscope 1 comprises an assembly comprising the first linear polarizer 3 and the illumination device 2, which are rotatable in unison around an axis which runs in parallel to the second optical path 8. Said assembly may be connected with each other by a rotatable mounting means. By rotating said mounting means, the polarization angle of said first polarizer 3 towards said sample inspection area 6 can be adjusted.
By adjustment of the transmission axis of said second linear polarizer 4, any light which has undergone polarization change due to polarization characteristics of a molecule in the sample can be allowed to pass said second linear polarizer 4, while reducing or blocking any light which has a different polarization angle. In a preferred embodiment, the transmission axis θΤΑ2 can be adjusted to allow any light polarized by the sample to pass through said second linear polarizer 4, while blocking or partly blocking light having polarization angle θι which hits the sample and is reflected without changing its polarization angle.
In another preferred embodiment, the microscope comprises a further light source 12 in the blue spectrum to observe fluorescent behavior of collagen (connective tissue), which is advantageous in a further method to distinguish nerves from collagen.
The further illumination device 12 is preferably mounted independently from the other light sources. The light from this source does not pass the first linear polarizer 3 or said second linear polarizer 4, and is capable of directly illuminating a sample on the sample inspecting area 6. It is preferred that said further illumination device 12 is disposed of an adjusting means to adjust the illumination angle towards the sample.
In a preferred embodiment, the illumination device 2 comprises a static white light emitting diode (LEDs). The intensity of the light source 2 can preferably be adjusted by a light adjustment means.
In a preferred embodiment, the angle of light source 12 is configurable, to provide a variable angle of the illumination with respect to a sample.
In a preferred embodiment, the center of said disc 19 is about 5 cm in diameter and contains the second linear polarizer 4. The outer rim, preferably about 3.5 cm in width of the same disk 19 is covered with the first linear polarizer 3. An advantage thereof is that the outer rim is broad enough to polarize most light from light source 2. The center of the disk 19 is located in the second optical path 8.
In a preferred embodiment, the microscope is configured such that the emitted, and preferably collimated light from light source 2 only passes the first polarizer 3 on the outer rim of the disk 19 directly upon the sample inspection area 6, whereas the second polarizer 4 only passes the (preferably collimated) polarized reflected light from a sample in the sample inspection area 6.
In figure 7, another embodiment of the microscope of the invention is shown. The microscope 1 includes a lens assembly 10, an illumination device 2, a first linear polarizer 3 and a second linear polarizer 4, a beam splitter 11 and an image capturing device 14, viewing arrangement 5 or eyepiece 13.
As illustrated in figure 7, the microscope according to this embodiment comprises an assembly (indicated in figure 7 with a dashed box) comprising a beam splitter 11, said first polarizer 3, and illumination device 2 connected with each other by a rotatable mounting means. By rotating said assemby, the polarization angle of said first polarizer 3 in relation to the sample inspection area 6 can be adjusted. The first linear polarizer 3 is located in the first optical path 7 of the light. The light passing through the first linear polarizer 3 is reflected via the beam splitter 11 to the sample inspection area 6. The polarized light is then reflected through the beam splitter 11, passing the second linear polarizer 4 leading to the, viewing arrangement 5, which may for example be an image capturing device 14 or eyepiece 13. Preferably, said first polarizer 3 is configured such that is can be rotated vis a vis said beam splitter 11. Said second polarizer 4 is configured so that it can be rotated vis a vis the sample inspection area 6 and independently of said assembly comprising said first linear polarizer 3, illumination device 2 and optional collimator 9 and said beam splitter 11. In another embodiment, said second polarizer 4 is fixed to said ensemble comprising said first linear polarizer 3, illumination device 2, said optional collimator 9 and said beam splitter 11.
In a preferred embodiment, a further illumination device 12 is mounted separately from the other light sources. The UV or blue light can directly illuminate the sample inspection area 6. When a biological sample is placed, the UV or blue light will allow some tissues to fluoresce, for example connective tissue. In contrast to the light from light source of illumination device 2, the fluorescent light generated by the sample will then pass through the center polarizer 4 and may be detected in the image capturing 5 or projected to the eye via an ocular 13.
Figure 8 shows another preferred embodiment of the microscope of the invention. This embodiment comprises the first linear polarizer 3 connected to illumination device 2 and optionally a collimator 9. The collimated polarized light directly illuminates the sample. Said first linear polarizer 3, illumination device 2 and optional collimator 9 are connected via a mounting means, to ensure that they can be rotated in unison with respect to the sample.
Figures 8 and 9 show another preferred embodiment of the microscope of the invention. Herein, said first polarizer 3 and the illumination device 2, the second polarizer 4 and optionally said collimator 9 are connected and attached to a mounting means which can be moved in a circular motion (indicated in Fig. 9 in gray) around optical path 8. This circular motion changes the polarization angle of said first polarizer 3 vis a vis the sample inspection area 6. In a preferred embodiment, said first polarizer 3 is rotatably mounted in said mounting means. This allows further adjustment of the polarization angle towards the sample. Preferably, said second polarizer 4 is rotatably mounted in the housing 18 to allow adjustment of the polarization angle towards the sample.
As shown in FIG. 4-9, the microscope 1 comprises a illumination device 2, suitable for illuminating a sample. Said illumination device 2 may comprise any light source which is suitable for producing visible light and may include a ring light, a LED, a halogen light, or a tungsten light. As illustrated in figures 4-9, the microscope may comprise a further illumination device 12 comprising light source in the ultraviolet (UV) spectrum (e.g. a 'black light') to observe fluorescent behavior of collagen (connective tissue) as a secondary method to distinguish nerves from collagen.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art.
CONCLUSIES
1. Microscoop (1) geschikt om een preparaat te inspecteren, omvattende een belichtings apparaat (2), een eerste lineaire polarisator (3), een tweede lineaire polarisator (4), een observatie inrichting (5) en een inspectieruimte (6):
5 omvattende een eerste lichtweg (7) die zich uitstrekt tussen het genoemde belichtingsappraat (2) en de inspectieruimte (6) en een tweede lichtweg (8) die zich uitstrekt tussen de inspectieruimte (6) en de genoemde observatie inrichting (5), waarbij de eerste lineaire polarisator (3) is geplaatst in de genoemde eerste lichtweg (7) en de tweede polarisator (4) is geplaatst in de genoemde tweede lichtweg (8),
10 waarbij de genoemde eerste lineaire polarisator (3) een eerste transmissie-as θΤΑ1 en de genoemde tweede polarisator (4) een tweede transmissie-as ΘΤΑ2 bezit, en waarbij de genoemde eerste transmissie-as 0TAi en/of tweede transmissie-as 0TA2 instelbaar is ten opzichte van de inspectieruimte (6).