Optical unit for fluorescent light image representation, in particular for an analysis device for detecting pathogens, and method for producing an optical unit

Abstract

The invention relates to an optical unit (10) for fluorescent light image representation, comprising an optical transmission fiber (12) designed to align electromagnetic radiation (S) emitted via the transmission fiber (12) with respect to an object (O) to be examined, and comprising at least one optical reception fiber (14) for acquiring electromagnetic radiation (S) reflected off the object (O).

Description

[0001] Description

[0002] Optical unit for fluorescence image display, in particular for an analysis device for detecting pathogens, and method for producing an optical unit

[0003] Technical area

[0004] The invention relates to an optical unit for fluorescent image display, which is characterized by a particularly advantageous structural design and the possibility of high resolution in image processing. Furthermore, the invention relates to a device for fluorescent image display with an optical unit according to the invention, in particular an analysis device for the microfluidic detection of pathogens via nucleic acid amplification, and a method for producing an optical unit.

[0005] State of the art

[0006] An optical unit for fluorescent image display with the features of the preamble of claim 1 is known from DE 601 23 884 T2. The known optical unit is characterized by an optical transmission fiber that emits the light passed through it via an optical lens in the form of an illumination lens onto an object to be examined. The light emitted by the object is received via an optical reception fiber arranged next to the optical transmission fiber and forwarded to an evaluation unit. Due to the single optical reception fiber, the resolution of the known optical unit for fluorescent image display is limited.

[0007] Disclosure of the invention The optical unit according to the invention for fluorescent light image display with the features of claim 1 has the advantage that it enables, in a constructively advantageous manner, an increased resolution or an improved processing of the electromagnetic radiation irradiated by an object by means of an optical transmission fiber and emitted by the object due to the irradiation. The electromagnetic radiation can preferably comprise light and in particular fluorescent light, and is also referred to below for short as light.

[0008] The invention is based on the idea of ​​radiating the electromagnetic radiation, in particular laser radiation, emitted by the optical transmission fiber onto the object to be examined not in a straight line or frontally with respect to the beam guidance axis of the transmission fiber, but at an angle with respect to the beam guidance axis of the transmission fiber. The beam guidance axis of the transmission fiber is understood to be a straight line that indicates the direction along which radiation emerging from the transmission fiber would propagate without further deflection. In particular, the beam guidance axis of the transmission fiber indicates the direction of the straight continuation from the end of the transmission fiber from which the radiation emerges. This makes it possible, in conjunction with several receiving fibers interacting with the transmission fiber, to simultaneously detect and evaluate several electromagnetic radiations or light from the object, received at different angles, using a transmission fiber.

[0009] Against the background of the above explanations, an optical unit for fluorescent light image display with the features of claim 1 is therefore provided such that it has a transmitting fiber which is designed to deflect, in particular to scatter, the electromagnetic radiation from a beam guidance axis by an angle, and that a plurality of receiving fibers are provided. The receiving fibers are designed in particular to detect the electromagnetic radiation emitted by the object. Preferably, at least some of the receiving fibers are arranged around the transmitting fiber and in particular parallel to the transmitting fiber. An embodiment of the transmitting fiber according to the invention is to be understood in particular as meaning that a part of the transmitting fiber, in particular a part of one end of the transmitting fiber, is designed to cause the deflection or scattering of the electromagnetic radiation.In particular, the part of the transmitting fiber can have an optical element, in particular a prism, or can be formed as such an optical element.

[0010] Advantageous further developments of the optical unit according to the invention for fluorescent light image display are listed in the subclaims.

[0011] Preferably, depending on how many receiving fibers are available or with how many receiving fibers the electromagnetic radiation emitted by the transmitting fiber and reflected by the object is to be detected, it is provided that the transmitting fiber comprises an optical element for deflecting the electromagnetic radiation, in particular an axicon, for example a double axicon or a polygon, in particular comprising a pyramid, and that the receiving fibers are preferably arranged at uniform angular intervals around the beam guidance axis of the transmitting fibers. In other words, this means that with a polygonal design of the optical element, the optical unit has a corresponding number of receiving fibers corresponding to the number of radiation planes or directions from which the electromagnetic radiation was deflected.The choice of the shape of the optical element preferably depends on the number of receiving fibers used, which are assigned to the respective transmitting fiber to receive the fluorescence radiation from the object caused by excitation radiation from this transmitting fiber. For example, if four or six receiving fibers are assigned to a transmitting fiber and, in particular, arranged around this transmitting fiber, the optical element can preferably be a pyramid with a square or hexagonal base and thus have four or six side surfaces.

[0012] According to an advantageous embodiment, the transmission fiber comprises a substrate at one end, on which the optical element is arranged. In particular, the optical element can be partially or completely accommodated in the substrate. In particular, the optical element can be accommodated in the substrate in such a way that a base area of ​​the optical element is flush with an outer side of the substrate and thus the base area forms part of the outer side, in particular an outer side of the substrate facing away from the transmission fiber. The end of the transmission fiber is in particular the end from which the emitted electromagnetic radiation is to emerge. The substrate can comprise plastic or be made of plastic. For example, the plastic is a polymer. The substrate can be designed as a polymer layer.The substrate preferably has the same refractive index as a core material in the transmitting fiber, so that light passing from the transmitting fiber into the substrate is advantageously not refracted.

[0013] In a further development of the last proposal, it can be provided that the transmitting fiber, in particular the optical element, additionally comprises a lens, in particular at the end of the transmitting fiber.

[0014] In a particularly preferred design embodiment of such an optical unit, it is provided that several, preferably identically designed transmitting fibers with identically designed optical elements are provided, that the optical elements of the transmitting fibers are arranged at regular intervals from one another or form a regular pattern, and that the receiving fibers are arranged in the regions between the transmitting fibers. Such an arrangement and design of the optical unit, in conjunction with correspondingly small diameters of the transmitting and receiving fibers, enables a very high resolution of the electromagnetic radiation emitted by the object to be examined or of the emitted light. For example, exactly one receiving fiber is arranged between each first transmitting fiber and each of the transmitting fibers arranged closest to the first transmitting fiber.

[0015] Particularly in the event that a specific area of ​​the object is illuminated by electromagnetic radiation from two transmitting fibers simultaneously, it is usually difficult to determine using the receiving fibers which transmitting fiber is generating the corresponding portion of the object's emitted light. In a further development of the last proposal, it is therefore provided that the radiation from two adjacent transmitting fibers can be detected using a receiving fiber, and that a control device is provided which controls the two adjacent transmitting fibers separately from one another in time. Temporarily separated control means that the object to be examined is first irradiated or illuminated by a first transmitting fiber, and then, after the irradiation by the first transmitting fiber has been stopped, the object is illuminated or irradiated by the second transmitting fiber.Due to this temporal sequence of irradiation, the radiation or light detected by one receiving fiber can be assigned to the corresponding transmitting fibers.

[0016] In a further preferred design of the optical unit, the transmitting and receiving fibers, particularly in the exit and entry areas, i.e., on the side facing the object, are provided with a common substrate, particularly a common polymer layer. The substrate can, in particular, be the substrate described above. This enables particularly simple alignment of the optical unit with the object to be examined and ensures that the transmitting and receiving fibers are always arranged in a (rigid) configuration relative to one another.

[0017] It is further preferred if the receiving fibers each have an additional optical element in the form of an optical lens, in particular a converging lens, at an entry region (i.e., on the side facing the object). The additional lens differs from the optical lens on the transmitting fiber, if necessary, by having a different refractive index or by allowing the radiation emitted by the object to be collected.

[0018] A further preferred design provides that a core material of the transmitting and receiving fibers forms a monolithic element in the exit and entry regions of the transmitting and receiving fibers. In particular, it is provided that a core material of the transmitting and receiving fibers in the exit and entry regions of the transmitting and receiving fibers is provided with a common substrate comprising or consisting of plastic, in particular a polymer layer. This substrate can in particular be the substrate described above. The optical element can, as explained above, preferably be at least partially or completely accommodated in the substrate. This achieves the rigid or stationary arrangement of the transmitting and receiving fibers described or claimed above in a particularly simple manner.

[0019] Furthermore, the invention also comprises a device for fluorescent light image display, in particular as an analysis device for detecting pathogens, with an optical unit according to the invention as described so far, wherein the device is characterized in that a device designed as a laser beam device is provided for generating the electromagnetic radiation.

[0020] Furthermore, in order to avoid reflections, it is particularly preferred if the laser beam device is designed as a pulsed laser beam device.

[0021] Finally, the invention also encompasses a method for producing an optical unit designed, in particular, in the manner described. The method provides that a bundle comprising a plurality of transmitting fibers and receiving fibers is first produced. Subsequently, the transmitting fibers and the receiving fibers are coated with a polymer layer at a common end region. Polygene-like depressions are then created on the transmitting fibers. The depressions are then filled with a filler material to produce the optical elements. Finally, optical lenses are preferably produced on the polymer layer and the filler material or the optical elements.

[0022] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments of the invention and from the drawings.

[0023] Short description of the drawings

[0024] Fig. 1 shows a schematic representation of a device for fluorescent light image display with the essential elements,

[0025] Fig. 2 shows a part of an optical unit of the device according to Fig. 1 in a simplified side view,

[0026] Fig. 3 shows a cross section in the region of the exit and entry areas of optical fibers of the optical unit of the device according to Fig. 1,

[0027] Fig. 4 is a perspective side view of the radiation when using a lens in the form of a double axicon, Fig. 5 is a plan view of an illumination area on an object generated by the double axicon according to Fig. 4,

[0028] Fig. 6 shows a section of an optical unit of the device of Fig. 1 in an enlarged view,

[0029] Fig. 7 is a flow chart explaining essential steps of the manufacturing process of the optical unit and

[0030] Fig. 8 to Fig. 10 each show simplified perspective representations of various process steps in the production of the optical unit.

[0031] Embodiments of the invention

[0032] Identical elements or elements with the same function are provided with the same reference numbers in the figures.

[0033] Figure 1 shows the essential components of a device 100 for fluorescence imaging of an object O to be examined. The device 100 can serve, for example, as a component of an endoscope with an extremely thin insertion tube for examination on the human body. Alternatively, it can also be used, for example, in medical diagnostic procedures or examination methods for examining larger areas of biological samples arranged, for example, on a silicon chip, in particular for an analysis device for detecting pathogens using PCR or isothermal nucleic acid amplification.

[0034] The device 100 comprises an optical unit 10, which comprises a plurality or several optical transmission fibers 12 and optical reception fibers 14. The optical transmission fibers 12 serve to guide or conduct electromagnetic radiation S, which in the illustrated embodiment is generated by a laser beam device 20, which is designed as a pulsed laser beam device 20. On the exit side of the optical transmission fibers 12 facing the object O, these each have an optical lens 22 (Fig. 2).

[0035] The optical receiving fibers 14 serve to receive the electromagnetic radiation S emitted by the object O and, with the interposition of an electronic circuit 25 (only indicated), to feed it, for example, to a camera 27. The optical receiving fibers 14 each have a further or additional optical lens 28 (Figs. 2, 6) on the receiving side facing the object O, which is preferably designed as a converging lens. For example, the optical lens 22 and the further or additional optical lens 28 have the same shape.

[0036] Fig. 2 shows a portion of the optical unit 10 in detail. In particular, it can be seen that the cores 34 of a transmitting fiber 12 and a receiving fiber 14, each surrounded by a cladding 31, 32, are covered at a front end region with a common plastic substrate in the form of a polymer layer 35. The material of the polymer layer 35 preferably has the same refractive index as the material of the cores 34 of the transmitting fibers 12 and the receiving fibers 14. According to a particular embodiment, the substrate can comprise or consist of the same material as the cores of the transmitting or receiving fibers. The diameter of the cores 34 is, for example, 20 μm. The cores 34 can be made of pure silicone or can be provided with a fluorine-doped coating, which forms the cladding 31, 32.The polymer layer 35 simultaneously forms a carrier unit 36 ​​on which the transmitting fibers 12 and receiving fibers 14 are arranged in the desired arrangement and at the desired distances from one another.

[0037] A depression 37 is formed in the polymer layer 35, flush with the respective transmission fiber 12, on the side facing away from the transmission fiber 12. The depression 37 is, as explained in more detail later, polygonal, in particular pyramid-shaped. The depression 37 is at least partially, in the illustrated embodiment completely, filled with a filler material which has a different or greater refractive index than the polymer layer 35, wherein the filler material forms an optical element 33 for deflecting or scattering the emitted electromagnetic radiation S. In other words, the optical element 33 is received in the depression 37 of the substrate 35, i.e. the polymer layer 35, so that the base area of ​​the optical element 33 is flush with the substrate side facing away from the transmission fiber 12. Furthermore, the refractive index of the optical element 33 and the optical lens 22 as well as the further oradditional optical lens 28. The two lenses 22, 28 are formed on the end face of the polymer layer 35 facing away from the transmitting fiber 12 and the receiving fiber 14, respectively, and on the optical element 33. They consist of a photoresist material. The optical unit 10 can be aligned with the object O by means of the carrier unit 36.

[0038] The optical transmission fibers 12 with the optical lenses 22, as well as the optical reception fibers 14 with the additional optical lenses 28, are each individually identical in design. In particular, the recesses 37 associated with the transmission fibers 12 for forming the optical element 33 are either axicon-shaped or polygonal. The recesses 37 are preferably polygonal, in particular pyramid-shaped or hexagonal.

[0039] According to the illustration in Fig. 4 and 5, when using a double axicon, the electromagnetic radiation S emitted by the optical transmission fiber 12 is radiated or scattered in a ring shape onto the object O. In contrast, with a polygonal design of the recess 37 and thus also of the optical element 33, the electromagnetic radiation S emitted by the transmission fiber 12 is deflected or scattered by the same angle a from a beam guidance axis 38 along radiation planes 39, corresponding to the number of side surfaces of the recess 37 (Fig. 1).

[0040] The optical receiving fibers 14 arranged laterally next to the optical transmission fiber 12 are aligned with their light incidence axes towards the object O in such a way that they run perpendicularly above the point of incidence A of the radiation S. The further optical lenses 28 serve as converging lenses to capture as much of the radiation S emitted by the object O as possible.

[0041] Fig. 3 shows a simplified version of an optical unit 10 in which the depressions 37 and thus also the radiation planes 39 are each hexagonal in shape or arranged, i.e. the light emitted via the respective transmission fiber 12 in the direction of the beam guidance axis 38 is deflected by an angle of 60° from the original direction. It is important that an optical transmission fiber 12 in this case is surrounded by six optical reception fibers 14 which are designed to detect the respective deflected portion of the electromagnetic radiation S. The illustration in Fig. 3 also shows that the arrangement of the optical transmission fibers 12 is regular or uniform with uniform distances a from one another.

[0042] When the transmitting fibers 12 are configured as a double axicon as shown in Figs. 4 and 5, it can be provided, in particular, that an optical transmitting fiber 12 is surrounded by a plurality of receiving fibers 14, each arranged at equal angular intervals around the beam guiding axis 38. These are symbolically represented in Fig. 5 in the form of, for example, five receiving fibers 14, each arranged at an angle of 72° to one another.

[0043] Fig. 6 shows that an impact point A of the object O can be illuminated simultaneously with electromagnetic radiation S by two optical transmission fibers 12 arranged next to one another. In order to be able to determine which portion of the radiation S emitted by the object O from the impact point A originates from which of the two transmission fibers 12 when an optical reception fiber 14 is located above the point P, it can be provided that the two optical transmission fibers 12 can be controlled by means of a control device 40 in such a way that the electromagnetic radiation S is emitted via the two transmission fibers 12 completely separated from one another in time.

[0044] Essential manufacturing or process steps for producing an optical unit 10 are explained below with reference to the flow diagram in Fig. 7 and the illustrations in Figs. 8 to 10 as follows: First, in a first step 101, a bundle 1000, shown in simplified form in Figs. 8 to 10, is produced, consisting of the transmitting fibers 12 and the receiving fibers 14, which are initially identical to the transmitting fibers 12. This bundle 1000 is then coated on the end face with the polymer layer 35 in a second step 102, wherein the material of the polymer layer 35 is deformable. In a third step 103, according to Figs. 8 and 9, the bundle 1000 is aligned with the polymer layer 35 to form a stamp element 1010 produced using the nanolithography process, in which stamp element the structures 1011 required to form the depressions 37 are designed as elevations. By placing the polymer layer 35 onto the stamp element 1010 (Fig.9) In a fourth step 104, the desired recesses 37 are created in the polymer layer 35 (Fig. 10). Subsequently, in a fifth step 105, the filler material for producing the optical elements 33 is introduced into the recesses 37 on the polymer layer 35, and the lenses 22, 28 are produced.

[0045] The optical unit 10 or device 100 described so far can be modified in a variety of ways without deviating from the inventive concept. Thus, the optical unit 10 with the transmitting fibers 12 and receiving fibers 14 can also be designed in a linear shape to realize a line-like scanning of the object O.

Claims

Claims 1. An optical unit (10) for fluorescent light imaging, in particular for an analysis device for detecting pathogens, comprising an optical transmission fiber (12) designed to direct electromagnetic radiation (S) emitted via the transmission fiber (12) onto an object (O) to be examined, and comprising at least one optical reception fiber (14) for detecting electromagnetic radiation (S) emitted by the object (O), characterized in that the transmission fiber (12) is designed to deflect, in particular to scatter, the electromagnetic radiation (S) from a beam guidance axis (38) by an angle (α), and in that a plurality of reception fibers (14) are provided which are designed to detect the electromagnetic radiation (S) emitted by the object (O).

2. Optical unit according to claim 1, characterized in that the transmitting fiber (12) comprises an optical element (33) for deflecting the electromagnetic radiation (S), in particular an axicon, for example a double axicon or a polygon, in particular comprising a pyramid, and that the receiving fibers (14) are preferably arranged at uniform angular intervals around the beam guiding axis (38) of the transmitting fibers (12).

3. Optical unit according to claim 1 or 2, characterized in that the transmitting fiber (12) comprises a substrate (35, 36) at one end, wherein preferably the optical element (33) is arranged on or at least partially in a recess (37) in the substrate (12).

4. Optical unit according to claim 1, 2 or 3, characterized in that that the transmitting fiber, in particular the optical element (33), additionally comprises a lens (22), in particular at the end of the transmitting fiber (12).

5. Optical unit according to one of claims 2 to 4, characterized in that in a polygonal design of the optical element (33), the number of receiving fibers (14) corresponds to the number of radiation planes (39) deflected from the beam guidance axis (38).

6. Optical unit according to one of claims 2 to 5, characterized in that a plurality of transmitting fibers (12) with preferably identically designed optical elements (33) are provided, that the optical elements (33) of the transmitting fibers (12) are arranged at regular distances from one another or form a regular pattern, and that the receiving fibers (14) are arranged in the regions between the transmitting fibers (12).

7. Optical unit according to claim 6, characterized in that the radiation (S) of two adjacent transmitting fibers (12) can be detected by means of a receiving fiber (14), and in that a control device (40) is provided which is designed to control the two adjacent transmitting fibers (12) separately from one another in time.

8. Optical unit according to one of claims 1 to 7, characterized in that the transmitting and receiving fibers (12, 14) are arranged at an end region, in particular at their end region facing the object (O), on a common carrier unit (36).

9. Optical unit according to one of claims 1 to 8, characterized in that the receiving fibers (14) each have a further optical element in the form of an optical lens (28), in particular a converging lens, at an entry region.

10. Optical unit according to one of claims 2 to 9, characterized in that a core material of the transmitting and receiving fibers (12, 14) in the exit and entry region of the transmitting and receiving fibers (12, 14) is provided with a common substrate, in particular comprising plastic, in particular a polymer layer (35), and that the optical element is preferably at least partially accommodated in the substrate.

11. Device (100) for fluorescent light image display, in particular analysis device for detecting pathogens, with an optical unit (10) designed according to one of claims 1 to 10, characterized in that a laser beam device (20) is provided as a device for generating the electromagnetic radiation (S).

12. Device according to claim 11, characterized in that the laser beam device (20) is designed as a pulsed laser beam device (20).

13. A method for producing an optical unit (10), which is preferably designed according to claims 1 to 10, comprising at least the following steps: - Creating a bundle (1000) with several transmitting fibers (12) and receiving fibers (14) - coating the transmitting fibers (12) and the receiving fibers (14) at a common end region with a polymer layer (35) - producing, in particular, polygene-like depressions (37) on the transmitting fibers (12) - filling the recesses (37) with a filling material to produce optical elements (33) - Preferably forming optical lenses (22, 28) on the polymer layer (35) and the optical elements (33).

14. Method according to claim 13, characterized in that that a stamp element (1010) with a structure (1011) having elevations is used to form the depressions (37).

15. The method according to claim 14, characterized in that the stamp element (1010) is produced by a nanolithography process.

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