Medical device and method for illuminating organic tissue with an adjustable wavelength spectrum

Abstract

The invention provides a medical device and a method for illuminating organic tissue (1) with an adjustable wavelength spectrum. The device (100; 200; 300; 400; 500; 600) comprises: a plurality of laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) for outputting a respective laser beam (10-i), wherein spectral ranges of the laser beams (10-i) differ from each other; a light guide (120) for guiding output laser light (2) to an organic tissue (1) to be illuminated; an optical coupling device (130) which is configured to couple the laser beams (10-i) into the light guide (120); a control device (140) by means of which it is selectively adjustable which laser beams (10-i) of which of the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) are coupled into the optical fiber (120) at a given time; wherein the optical coupling device (130) comprises at least one diffractive optical element (132); and wherein laser beams (10-i) of different spectral ranges emitted by the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) strike the diffractive optical element (132) in such a way that they are spatially superimposed by it, and that the laser beams thus spatially superimposed are coupled into the optical fiber (120) in a common beam as output laser light (2).

Description

Technical field of the invention

[0001] The present invention relates to a device and a method for illuminating organic tissue with an adjustable wavelength spectrum. The device can be used, in particular, in a medical instrument or medical imaging device, such as an endoscope, an exoscope, or a surgical microscope. Background of the invention

[0002] In modern medicine, imaging techniques are frequently used. Medical imaging equipment is employed to capture images of a medical scene. These images can provide a user, such as a surgeon, with information that the user could not visually perceive without aids, for example, because the information is based on electromagnetic radiation with non-visible wavelengths.

[0003] Organic tissue reacts differently to electromagnetic excitation radiation with varying spectral ranges. Therefore, by using excitation radiation with a specific spectral range, a particular reaction can be generated, allowing for the investigation of specific properties of the organic tissue. The organic tissue can also be labeled with various markers, such as fluorescent markers, which react to yet other spectral ranges. If excitation radiation with a very broad spectral range is emitted, this can sometimes lead to weak reactions, especially when different reactions are to be generated using the same device. Furthermore, the maximum total power of the excitation radiation is limited due to the sensitivity of organic tissue.

[0004] For example, German patent DE 10 115 590 A1 describes a scanning microscope with a laser that emits a light beam of a first wavelength, directed onto an optical element that partially modifies the wavelength of the light beam, using means to suppress the light beam of the first wavelength. Thus, only a portion of the laser power is used for irradiation, and there are no settings for different wavelengths. Summary of the invention

[0005] It is therefore an object of the present invention to provide an improved device and an improved method for illuminating organic tissue, which allow for greater flexibility in use and at the same time better results.

[0006] This problem is solved by the subject matter of the independent patent claims.

[0007] According to a first aspect, the invention provides a medical device for illuminating organic tissue with an adjustable wavelength spectrum, comprising: a plurality of laser diodes, wherein each laser diode is configured to emit a laser beam and spectral ranges of the laser beams of at least two laser diodes (preferably all laser diodes) differ from each other; a light guide for directing output laser light to an organic tissue to be illuminated, in particular onto an organic tissue to be illuminated; an optical coupling device which is designed to couple the laser beams of the laser diodes into the optical fiber; a control device by means of which it is possible to selectively adjust which laser beams of the laser diodes are coupled into the optical fiber at a given time; wherein the optical coupling device comprises at least one diffractive optical element; and wherein the optical coupling device and the laser diodes are designed and arranged such that laser beams of different spectral ranges emitted by the laser diodes strike the diffractive optical element at predefined different angles in such a way that they are spatially superimposed by it, and that the laser beams thus spatially superimposed are coupled into the optical fiber in a common beam as output laser light.

[0008] Only the spectral ranges of some laser diodes can differ; however, preferably the spectral ranges of all laser diodes are different. In this way, a particularly high number of different wavelength spectra of the output laser light can be generated, while simultaneously keeping the number of laser diodes, and thus typically also the size of the device, compact.

[0009] That two spectral ranges are different can mean that they have different starting and / or ending wavelengths, or even that they are completely disjoint (i.e., they do not overlap at any wavelength). For example, the spectral ranges of all laser diodes can be disjoint.

[0010] The laser beams are initially generated spatially separately by the laser diodes, combined at the diffractive element, and finally spatially homogenized within the optical fiber, for example by mixing individual fibers within the fiber. The optical fiber can, for instance, comprise or consist of one or more glass or plastic fibers.

[0011] The spatial arrangement of laser diodes depends particularly on the spatial arrangement of their respective laser emission points, which are preferably implemented by collimation optics. This distinction is typically irrelevant if the actual semiconductor laser emitters of the laser diodes are directly connected to their associated collimation optics. However, if the actual semiconductor laser emitters are connected to their respective laser emission points (e.g., of collimation optics) via optical fibers, then the spatial arrangement of the laser diodes refers specifically to the spatial arrangement of the laser emission points (e.g., of collimation optics).

[0012] According to some preferred embodiments, variants, or refinements of embodiments, the optical coupling device comprises a first lens by means of which the laser beams emitted by the laser diodes are deflected such that they strike the diffractive optical element at predefined different angles. The first lens may have one or more axes of refraction.

[0013] According to some preferred embodiments, variants, or refinements of embodiments, the laser diodes are arranged such that they emit the laser beams parallel to each other. Additionally or alternatively, the laser diodes can be arranged in at least one row or in a regular grid.

[0014] Alternatively, the laser emitters can simply be laser output points (e.g., collimation optics) of the laser diodes, arranged such that they emit the laser beams parallel to each other and / or arranged in at least one row or in a regular grid. The actual semiconductor laser emitters are connected to the laser output points, particularly the collimation optics, via optical fibers. This allows for a high degree of design freedom in the arrangement of the actual semiconductor laser emitters, which also simplifies thermal management.

[0015] According to some preferred embodiments, variants, or refinements of embodiments, the laser diodes, or at least laser emission points (preferably collimation optics) of the laser diodes, are arranged such that they emit the laser beams toward a common point, the common point being advantageously located in or on the diffractive element. Additionally or alternatively, the laser diodes, or at least the laser emission points of the laser diodes, can be arranged on a circular arc or a spherical shell.

[0016] According to some preferred embodiments, variants or refinements of embodiments, at least one of the laser diodes, preferably several of the laser diodes, particularly preferably all of the laser diodes, has a respective spectral range with a spectral width of particularly 10 nanometers or less, particularly preferably 6 nanometers or less, for example 1 nanometer or less.

[0017] According to some preferred embodiments, variants or refinements of embodiments, the laser diodes are wavelength-stabilized in themselves.

[0018] According to some preferred embodiments, variants or refinements of embodiments, the optical coupling device has a partially reflective mirror which provides optical feedback for the laser diodes as an external resonator.

[0019] According to some preferred embodiments, variants or refinements of embodiments, the diffractive optical element is designed as a transmittive diffraction grating or as a reflective diffraction grating.

[0020] According to some preferred embodiments, variants, or refinements of embodiments, at least some of the laser diodes can be switched on and off by means of the control device in order to adjust the wavelength spectrum of the output laser light. The laser diodes can be arranged such that, when switched on, their respective laser light is automatically coupled into the optical fiber (i.e., solely by the internal composition of the device). In this way, a desired wavelength spectrum of the output laser light can be easily adjusted by switching specific laser diodes on or off.

[0021] Whenever switching on or off (or blocking / passing, filtering / unfiltering, etc.) is mentioned herein, particularly in connection with the control unit, it should also be understood that an existing state can be maintained. For example, if laser diodes A, B, and C are currently active and it is desired that laser diodes B, C, and D should now be active, then switching on by the control unit includes actually switching on laser diode D as well as leaving laser diodes B and C switched on. Alternatively, whenever an indication is given that the wavelength spectrum needs to be changed, all active laser diodes could first be switched off (here, A, B, and C), and then all laser diodes required for the new wavelength spectrum could be switched on (here, B, C, and D).

[0022] Alternatively, the laser diodes can only be switched on and off together, with the laser beams of the laser diodes being shielded by mechanical shutters or filtered out by switchable filters, controlled by the control unit, to provide the desired wavelength spectrum of the output laser light. It is also possible that the laser diodes can be moved by actuators through mechanical translation and / or rotation, controlled by the control unit, such that their laser beams strike the diffractive element at an angle at which the corresponding laser beams are selectively or selectively not coupled into the optical fiber.

[0023] In other words, selectively adjusting which laser beams should currently be composed of the output laser light can be achieved either by generating only certain laser beams through the laser diodes (and then coupling all the generated laser beams into the optical fiber), or by generating all laser beams, but only coupling certain ones into the optical fiber (either because laser beams are interrupted or because they are not directed in such a way that they are coupled in).

[0024] According to some preferred embodiments, variants or refinements of embodiments, the device is an endoscope, an exoscope, or a surgical microscope.

[0025] Furthermore, according to a second aspect, the invention provides a method for illuminating organic tissue with an adjustable wavelength spectrum, comprising the steps of: - Providing a plurality of laser diodes, each laser diode being configured to emit a laser beam and the spectral ranges of the laser beams of at least two laser diodes being different from each other; - Selecting a wavelength spectrum for an output laser light, especially within a predefined selection; - spatial superposition of laser beams simultaneously striking a diffractive element by the diffractive element; - Coupling the spatially superimposed laser beams into a common beam as output laser light into a fiber optic cable; - Selective adjustment, depending on the wavelength spectrum selected for the output laser light, of which laser beams of the laser diodes are coupled into the optical fiber at any given time in order to adjust the selected wavelength spectrum of the output laser light; and - Illuminating the organic tissue with the initial laser light, especially with the selected

[0026] Wavelength spectrum or the best possible approximation.

[0027] The output laser light can, for example, be emitted directly from the light guide onto the organic tissue. However, it is also conceivable that further optical elements such as lenses, mirrors, etc., are arranged between the light guide and the organic tissue.

[0028] Further advantageous variants, options, embodiments, and modifications will become apparent from the following figures, the detailed description, and the dependent claims. It is understood, however, that while the detailed description and specific examples indicate preferred embodiments of the invention, they are provided for illustrative purposes only, as various changes and modifications within the scope of the invention are obvious to the person skilled in the art. Brief description of the characters

[0029] Individual embodiments of the present disclosure will be explained in detail with reference to the following figures. The components in the drawings are not necessarily to scale, but serve to illustrate the principles of the present invention. Parts in the various figures that correspond to the same elements or process steps have been provided with the same reference numerals in the figures. The numbering of process steps initially serves only to distinguish them and does not necessarily imply a corresponding sequence; however, it is one option to carry out the steps in the order of their numbering. Several steps can also be carried out overlapping or simultaneously. The figures show: Fig. 1 a schematic representation of a device according to an embodiment of the present invention; Fig. 2 a schematic representation of a device according to a further embodiment of the present invention; Fig. 3 a schematic representation of a device according to yet another embodiment of the present invention; Fig. 4 a schematic representation of a device according to yet another embodiment of the present invention; Fig. 5 a schematic representation of a device according to yet another embodiment of the present invention; Fig. 6 a schematic representation of a device according to yet another embodiment of the present invention; and Fig. 7 a schematic flowchart to illustrate a method according to yet another embodiment of the present invention. Detailed description of the figures

[0030] Fig. Figure 1 shows a schematic representation of a device according to an embodiment of the present invention, i.e. a device 100 for illuminating organic tissue 1 with an adjustable wavelength spectrum, i.e. with output laser light 2 with an adjustable wavelength spectrum.

[0031] The device 100 comprises a plurality of laser diodes 110-1,..., 110-i,..., 110-N (hereinafter also referred to collectively as 110-i). Each laser diode 110-i is configured to emit a corresponding laser beam 10-1,...,10-i,..., 10-N (hereinafter also referred to collectively as 10-i).

[0032] The spectral ranges of at least two 110-i laser diodes differ from each other, with the spectral ranges of all 110-i laser diodes preferably differing from each other. The different spectral ranges are in Fig. 1 schematically with λ1,...,λ i ,...,λ N(hereinafter also partly summarized as λ) i ). The spectral ranges λ i can (partially or all) be so narrowly defined that the 110-i laser diodes can essentially be described as monochromatic. For example, the spectral ranges λ i have a width of 10 nanometers or less, particularly preferably 6 nanometers or less, for example 1 nanometer or less.

[0033] In order to adjust the wavelength spectrum of the output laser light 2 (or its intended wavelength spectrum), which is used to illuminate the organic tissue 1, the invention allows for the adjustment of which laser beams from laser diodes 110-i are coupled together into an optical fiber 120 as the output laser light 2, for example, by means of a coupling lens 136. This is achieved by a control unit 140 of the device 100 in combination with a coupling device 130 of the device 100. The control unit 140 is configured to receive a control signal 71, which provides information about the desired output laser light 2 either directly or indirectly.

[0034] For example, the control signal 71 can precisely instruct the control unit 140 which actions it must take (i.e., how the control unit 140 must control controllable elements of the device 100) in order to generate the desired output laser light 2. Alternatively, the control signal 71 can only specify the wavelength spectrum of the desired output laser light 2, and the control unit 140 can be configured to control the device 100 based on this.

[0035] At the in Fig. In the embodiment shown in Figure 1, the laser diodes 110-i are arranged such that they generate their respective laser beams 10-i parallel to each other. For this purpose, the laser diodes 110-i can, for example, be arranged parallel to each other in a two-dimensional arrangement (series) or in a three-dimensional arrangement, in each case in particular regularly (e.g. in a regular grid).

[0036] The coupling device 130 comprises a first lens 134, which can also be called a transform lens. The first lens 134 is designed and arranged such that all the laser beams 10-i generated by the laser diodes 110-i can strike it and are all refracted in such a way that they strike a diffractive element 132 located behind the first lens 134 and superimpose there, i.e., are combined into a common beam that represents the subsequent output laser light 2. Depending on the arrangement of the laser diodes 110-i, the first lens 134 can have one or more axes of refraction for this purpose.

[0037] The diffractive element 132 can, as in Fig. 1 is shown to be designed as a transmittive diffraction grating, although alternatively a design as a reflective diffraction grating is also possible.

[0038] Since the diffraction by the diffractive element 132 depends on the wavelength or the spectral ranges λ i Depending on the laser beams 10-i, the laser diodes 110-i, the diffractive element 132, and the first lens 134 are arranged such that all active laser beams 10-i are directed together onto the coupling lens 136 in such a way that the laser beams 10-i are coupled into the common optical fiber 120. In particular, all laser beams 10-i that currently strike the diffractive element 132 can be focused in a common optical axis OA.

[0039] At the in Fig. In the embodiment shown in Figure 1, the laser diodes 110-i are each wavelength-stabilized. The common output laser light 2 essentially possesses (at least to a first approximation) the beam quality of a single beam, i.e., a beam quality as if it had been generated by a single laser diode 110-i. Simultaneously, the output laser light 2 exhibits the total power and the combined spectral ranges λ. i all involved laser beams 10-i. By (approximately) preserving the beam quality in the combined beam of the output laser light 2, it can be coupled into the optical fiber 120 with very low loss using the coupling lens 136.

[0040] Since in the embodiment of Fig. Since the coupling device 130 is completely passive, the selection of the laser diodes 110-i that are currently switched on (i.e., generating their respective laser beams 10-i) determines the wavelength spectrum with which the output laser light 2 is generated. The control signal 71 can thus indicate the selection of the laser diodes 110-i, whereupon the control device 140 switches the selected laser diodes 110-i on or off (and / or leaves them switched on or off). Alternatively, the control signal 71 can indicate the desired wavelength spectrum, whereupon the control device 140 automatically selects which laser diodes 110-i must simultaneously contribute to the output laser light 2 and performs the corresponding switching on and / or off (if necessary).

[0041] If, as explained above, the selection of the laser beams 110-i contributing to the output laser light 2 is not achieved by switching the laser diodes 110-i on and off, but in another way, the control signal 71 and / or control device 140 can be configured accordingly. The control device 140 can, for example, open or close mechanical shutters (to block unwanted laser beams 10-i and allow desired laser beams 10-i to pass through), add controllable filters, change the angle of incidence of laser beams 10-i on the diffractive element 132, and / or the like. The control signal 71 can receive precise instructions for this, or the control device 140 can be configured to automatically determine and make the corresponding settings based on a desired wavelength spectrum of the output laser light 2 displayed in the control signal 71.

[0042] It can be provided that the control signal 71 can display any wavelength spectra, including those that cannot be exactly generated by any combination of laser beams 10-i of the laser diodes 110-i. In this case, the control device 140 can be configured to select and generate the most suitable wavelength spectrum that can be produced by the device 100, for example, based on a stored table, in particular using interpolation, or the like.

[0043] The control signal 71 can, for example, be provided or generated by an input interface 150 of the device 100. The input interface 150 can be a user interface by means of which a user of the device 100 can directly specify parameters regarding the output laser light 2 to be emitted. The user interface can be implemented, for example, by a touchscreen, a selection switch, a voice input interface, and / or the like.

[0044] Alternatively or additionally, the input interface 150 can also be configured to receive the control signal 71 from outside the device 100, for example from an operating room control system, from a camera control of an endoscope and / or the like.

[0045] As explained above, the device 100 can itself be part of a medical instrument or medical imaging device, or be designed as such, for example as an endoscope, exoscope, or operating microscope.

[0046] Accordingly, the device 100 can include an image acquisition device 160 by means of which a response radiation 3 from the organic tissue 1, which was excited in the organic tissue 1 by the output laser light 2, can be detected (and optionally evaluated).

[0047] Fig. Figure 2 shows a schematic representation of a device according to a further embodiment of the present invention, i.e., a further device 200 for illuminating organic tissue 1 with an adjustable wavelength spectrum, i.e., with output laser light 2 with an adjustable wavelength spectrum.

[0048] In the device 200 from Fig. 2 will be replaced by wavelength-stabilized laser diodes 110-i Fig. One 210-1 laser diode is used, which is spectrally stabilized externally. In the Fig. In the variant shown, this is achieved by a partially reflective mirror 238, which reflects, for example, 5%–20%, e.g., 10%, of the incident laser light as optical feedback for the laser diodes 210-i. This provides external wavelength stabilization for the laser diodes 210-i. The partially reflective mirror 238 can, for example, be arranged between the coupling lens 136 and the diffractive element 132, such that laser light transmitted by the partially reflective mirror 238 is coupled through the coupling lens 136 into the optical fiber 120.

[0049] Fig. Figure 3 shows a schematic representation of a device according to yet another embodiment of the present invention, i.e., a further device 300 for illuminating organic tissue 1 with an adjustable wavelength spectrum.

[0050] The device 300 from Fig. 3 is a variant of device 100 made from Fig. 1 and differs from this in the arrangement and design of its laser diodes 310-1,...,310-i,...,310-N. In the device 300, on the one hand the actual semiconductor laser emitters 313-1,...,313-i,...,313-N of the laser diodes 310-i, and on the other hand respective laser exit points, namely collimation optics 312-1,...,312-i,...,312-N of the laser diodes 310-i, from which the laser beams 10-i generated by the semiconductor laser emitters 313-i are initially emitted, are connected to each other by a respective optical fiber 311-1,...,311-i,...,311-N of the laser diodes 310-i, but are spatially separated.

[0051] In contrast, in devices 100 and 200 described above, the laser diodes 110-i and 210-i are each configured with semiconductor laser emitters and collimation optics mounted directly adjacent to one another. By comparing the schematic representations in Fig. 1 and Fig. The difference becomes clear in step 3.

[0052] Accordingly, (instead of the entire laser diodes 110-i as in device 100) Fig. 1) In the device 300, the collimation optics 312-i are specifically arranged such that the laser beams 10-i coupled out of these collimation optics 312-i strike the diffractive element 132 in the same manner as with respect to the entire laser diodes 110-i in Fig. 1 described. In particular, the collimation optics 312-i can be arranged in one or more rows or in a regular grid etc., such that the coupled-out laser beam 10-i hits the diffractive element 132 at the correct angle in order to be combined by it with all other laser beams 10-i.

[0053] Fig. Figure 4 shows a schematic representation of a device according to yet another embodiment of the present invention, i.e., a further device 400 for illuminating organic tissue 1 with an adjustable wavelength spectrum. Device 400 is a variant of device 100 from Fig. 1 and differs from this in that its laser diodes 410-1,...,410-i,...,410-N are arranged on a circular arc or a spherical shell such that the first lens 134 (i.e., a lens between the laser diodes 410-i and the diffractive element 132) can be omitted. Instead, the (intrinsically wavelength-stabilized) laser diodes 410-i (in particular their laser emission points, e.g., collimation optics) are arranged such that the laser beams 10-i emitted by them each strike the diffractive element 132 at such angles, in particular at the same point, that they are combined by the diffractive element 132.

[0054] Fig. Figure 5 shows a schematic representation of a device according to yet another embodiment of the present invention, i.e., a further device 500 for illuminating organic tissue 1 with an adjustable wavelength spectrum. Device 500 is a variant of device 400 from [reference missing]. Fig. 4 and differs from this in that its laser diodes 510-1,...,510-i,...,510-N are not wavelength-stabilized in themselves (as is the case with the laser diodes 410-i), but are spectrally stabilized externally, for example by the partially reflective mirror 238, as already described with reference to Fig. 2 was described. In other words, the device 500 differs from Fig. 5 in the same way from the device 400 Fig. 4, how the device 200 is constructed Fig. 2 from the device 100 Fig. 1 distinguishes.

[0055] Fig. Figure 6 shows a schematic representation of a device according to yet another embodiment of the present invention, i.e., a further device 600 for illuminating organic tissue 1 with an adjustable wavelength spectrum. Device 600 is a variant of device 300 from [reference missing]. Fig. 3, wherein instead of the first lens 134 for focusing the laser beams 10-i onto the diffractive element 132, an arrangement of the collimation optics 312-i on a circle or a spherical shell is used. In other words, the device 600 differs from Fig. 6 in the same way from the device 300 Fig. 3, how the device 400 is constructed Fig. 4 from the device 100 Fig. 1 distinguishes.

[0056] It is understood that in both the device 300 and the device 600, the laser diodes 310-i (in particular their semiconductor laser emitters 313-i) can be designed to be wavelength-stabilized (as in Fig. 3 or Fig. 6 is shown schematically), or alternatively, wavelength-stabilized externally, as described above with reference to the partially reflective mirror 238.

[0057] Fig. Figure 7 shows a schematic flowchart to explain a method for illuminating organic tissue with an adjustable wavelength spectrum according to a further embodiment of the present invention. The method is also described below with reference to the Fig. 1 and Fig.2 and the reference numerals used therein will be explained. The method can, in principle, be carried out independently of the device according to the invention, but can be adapted according to all options, variants, and further developments described in relation to the device according to the invention (in particular one of the devices 100; 200) and vice versa.

[0058] In step S10, a plurality of laser diodes 110-i; 210-i; 310-i; 410-i; 510-i are provided, each laser diode 110-i; 210-i; 310-i; 410-i; 510-i being configured to output a respective laser beam 10-i and the spectral ranges λ i the laser beams 10-i of at least two laser diodes 110-i; 210-i; 310-i; 410-i; 510-i can be distinguished from each other.

[0059] In step S20, a wavelength spectrum for a desired output laser light 2 is selected from a predefined range. This can be done, for example, by a control signal 71, as explained in detail above. Accordingly, the selection can be made, in particular, via a user interface, so that the selection process S20 can include or consist of receiving user input.

[0060] In step S30, laser beams 10-i striking a diffractive element 132 simultaneously are spatially superimposed by the diffractive element 132.

[0061] In step S40, the spatially superimposed laser beams 10-i are coupled into a common beam as output laser light 2 into a light guide 120, e.g. by means of a coupling lens 136, as described above.

[0062] In step S50, a selective adjustment is made, depending on the wavelength spectrum selected for the output laser light 2 in step S20, of which laser beams of which of the laser diodes 110-i; 210-i; 310-i; 410-i; 510-i are coupled into the optical fiber 120 at a respective time in order to adjust the selected wavelength spectrum of the output laser light 2.

[0063] As explained in detail above, this can be achieved, for example, by selectively switching the laser diodes 110-i; 210-i; 310-i; 410-i; 510-i on and off, or by one of the described alternatives (selective shielding, filtering, and the like).

[0064] In step S60, the organic tissue 1 is illuminated with the output laser light 2 coupled into the light guide 120.

[0065] In step S70, a response radiation 3 emanating from the organic tissue 1 and excited by the output laser light 2 can be detected, which can then be evaluated in step S80 and / or displayed in step S90, for example on a screen, for instance in false colors and / or as a superimposition over an RGB image of the organic tissue 1.

[0066] The foregoing description of the disclosed embodiments contains only examples of possible implementations, which are described to enable a person skilled in the art to manufacture or use the present invention. Various variations and modifications of these embodiments are readily apparent to a person skilled in the art – upon knowledge of the present invention – and the general principles defined herein can be applied to other embodiments without departing from the scope of this disclosure.

[0067] Therefore, the present invention is not to be limited to the specific embodiments shown herein, but is to be granted the broadest scope that is consistent with the principles and features disclosed herein. Reference symbol list 1 organic tissue 2 output laser light 3 Response radiation 10-i laser beam 71 Control signal 100 Medical Devices 110-i laser diode 120 fiber optic cables 130 coupling device 132 diffractive optical element 134 lens 136 coupling lens 140 Control unit 150 Input interface 160 Image capture device 200 Medical Devices 210-i laser diode 238 partially reflective mirror 300 Medical Devices 310-i laser diode 311-i fiber optic cable 312-i collimation optics 313-i semiconductor laser emitter 400 Medical Device 410-i laser diode 500 Medical Devices 510-i laser diode 600 Medical Devices OA Optical Axis S10..S90 Procedure steps QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 115 590 A1

[0004]

Claims

[1] Medical device (100; 200; 300; 400; 500; 600) for illuminating organic tissue (1) with adjustable wavelength spectrum, comprising: a plurality of laser diodes (110-i; 210-i; 310-i; 410-i; 510-i), wherein each laser diode (110-i; 210-i; 310-i; 410-i; 510-i) is configured to emit a laser beam (10-i) and spectral ranges of the laser beams (10-i) of at least two laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) differ from each other; a light guide (120) for guiding output laser light (2) to an organic tissue (1) to be illuminated; an optical coupling device (130) which is configured to couple the laser beams (10-i) of the laser diodes (110-i; 210-i) into the optical fiber (120); a control device (140) by means of which it is selectively adjustable which laser beams (10-i) of which of the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) are coupled into the optical fiber (120) at a given time; wherein the optical coupling device (130) comprises at least one diffractive optical element (132); and wherein the optical coupling device (130) and the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) are designed and arranged such that laser beams (10-i) of different spectral ranges emitted by the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) strike the diffractive optical element (132) at predefined different angles such that they are spatially superimposed by it, and that the laser beams thus spatially superimposed are coupled into a common beam as output laser light (2) in the optical fiber (120). [2] Device (100; 200; 300) according to claim 1, wherein the optical coupling device (130) has a first lens (134) by means of which the laser beams (10-i) emitted by the laser diodes (110-i; 210-i; 310-i) are deflected such that they strike the diffractive optical element (132) at the predefined different angles, wherein the first lens (134) has one or more axes of refraction. [3] Device (100; 200; 300) according to claim 2, wherein the laser diodes (110-i; 210-i; 310-i) or at least laser exit points (312-i) of the laser diodes (310-i) are arranged such that they emit the laser beams (10-i) parallel to each other and / or wherein the laser diodes (110-i; 210-i) or at least the laser exit points (312-i) of the laser diodes (310-i) are arranged in a row or in a regular grid. [4] Device (400; 500; 600) according to claim 1, wherein the laser diodes (410-i; 510-i) or at least laser emission points (312-i) of the laser diodes (310-i) are arranged such that they emit the laser beams (10-i) towards a common point and / or wherein the laser diodes (410-i; 510-i) or at least the laser emission points (312-i) of the laser diodes (310-i) are arranged on a circular arc or a spherical shell. [5] Device (100; 200; 300; 400; 500; 600) according to any one of claims 1 to 4, wherein at least one of the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i), preferably several of the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i), particularly preferably all of the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i), have a respective spectral range with a spectral width of 10 nanometers or less, preferably of 6 nanometers or less, particularly preferably of 1 nanometer or less. [6] Device (100; 300; 400; 600) according to any one of claims 1 to 5, wherein the laser diodes (110-i; 310-i; 410-i) are wavelength-stabilized in themselves. [7] Device (200; 500) according to one of claims 1 to 5, wherein the optical coupling device (130) has a partially reflective mirror (238) which provides optical feedback for the laser diodes (210-i; 510-i) as an external resonator. [8] Device (200; 500) according to claim 7, wherein the partially reflective mirror (238) is arranged between the diffractive optical element (132) and the light guide (120). [9] Device (100; 200; 300; 400; 500; 600) according to any one of claims 1 to 8, wherein the diffractive optical element (132) is configured as a transmittive diffraction grating or as a reflective diffraction grating. [10] Device (100; 200; 300; 400; 500; 600) according to any one of claims 1 to 8, wherein at least a part of the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i), in particular individually, can be switched on and off by means of the control device (140) in order to adjust the wavelength spectrum of the output laser light (2). [11] Device (100; 200; 300; 400; 500; 600) according to any one of claims 1 to 9, wherein the device (100; 200; 300; 400; 500) is an endoscope. [12] Method for illuminating organic tissue with an adjustable wavelength spectrum, comprising the steps: - Providing (S10) a plurality of laser diodes (110-i; 210-i; 310-i; 410-i; 510-i), wherein each laser diode (110-i; 210-i; 310-i; 410-i; 510-i) is configured to emit a laser beam (10-i) and the spectral ranges of the laser beams (10-i) of at least two laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) differ from each other; - Selecting (S20) a wavelength spectrum for an output laser light (2), in particular within a given selection; - spatial superposition (S30) of laser beams (10-i) incident simultaneously on a diffractive element (132) by the diffractive element (132); - Coupling (S40) of the spatially superimposed laser beams (10-i) into a common beam as output laser light (2) into a light guide (120); - Selective adjustment (S50) depending on the wavelength spectrum selected for the output laser light (2), laser beams (10-i) of which of the laser diodes (110-i; 210-i; 310-i; 410-i; 510-i) are coupled into the optical fiber (120) simultaneously at any given time in order to adjust the selected wavelength spectrum of the output laser light (2); and - Illumination (S60) of the organic tissue (1) with the output laser light (2).

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