Medical light source device

Abstract

This medical light source device comprises: a light source that outputs light for providing white light for illumination and excitation light for medication excitation; and an optical system that guides the light from the light source to an external light guide. The optical system includes at least one lens. The at least one lens satisfies a condition that the content of yttrium oxide be less than 10 wt% and / or a condition that the content of gadolinium oxide be less than 1 wt%.

Description

Medical light source device

[0001] The present disclosure relates to a medical light source device.

[0002] As disclosed, for example, in Patent Document 1, it is known that a light source device that outputs white light is used in the medical field such as endoscopes.

[0003] International Publication No. 2020 / 036112

[0004] Some endoscopes and the like are capable of drug fluorescence observation. The light source device outputs white light for illumination and excitation light for drug excitation. When such light passes through the optical system in the light source device, autofluorescence in a wavelength band overlapping the wavelength band of fluorescence is generated, which may reach the drug. The autofluorescence becomes noise and reduces the accuracy of drug fluorescence observation.

[0005] One aspect of the present disclosure suppresses a decrease in accuracy of drug fluorescence observation.

[0006] A medical light source device according to one aspect of the present disclosure includes: a light source that outputs light for obtaining white light for illumination and excitation light for drug excitation; and an optical system that guides light from the light source to an external light guide, wherein the optical system includes at least one lens, and the at least one lens satisfies at least one of a condition that a content of yttrium oxide is less than 10% by weight and a condition that a content of gadolinium oxide is less than 1% by weight.

[0007] This figure shows an example of the schematic configuration of the light source device 1 according to the embodiment. This figure shows an example of measurement results. This figure shows an example of measurement results. This figure shows an example of measurement results. This figure shows an example of measurement results. This figure shows an example of the arrangement of the rear lens 4-L. This figure shows an example of the schematic configuration of the light source device 1. This figure shows an example of the schematic configuration of the light source device 1. This figure shows an example of the schematic configuration of the light source device 1. This figure shows an example of measurement. This figure shows an example of measurement. This figure shows an example of the schematic configuration of the endoscope system 11. This is a block diagram showing an example of the schematic configuration of the endoscope system 11. This is a block diagram showing an example of the schematic configuration of the CCU 14. This figure shows an example of the schematic configuration of the endoscope system. This is a block diagram showing an example of the functional configuration of the camera and CCU shown in Figure 15. This figure shows an example of the schematic configuration of the microsurgical system.

[0008] Embodiments of this disclosure will be described in detail below with reference to the drawings. In each of the following embodiments, the same elements will be denoted by the same reference numerals to avoid redundant descriptions.

[0009] This disclosure will be described in the following order of items: 0. Introduction 1. Embodiments 2. Conclusion 3. Application Examples 4. Application Examples

[0010] 0. Introduction In the medical field, with the development of surgical techniques, the use of endoscopes, surgical microscopes, etc., is progressing. The light source devices that emit white light used to illuminate the observation area (affected area, etc.) consist of lamp light sources such as xenon lamps and halogen lamps, and LED (Light Emitting Diode) light sources. The same applies to both flexible and rigid endoscopes.

[0011] Some endoscopes and surgical microscopes are capable of observing the fluorescence of drugs. This involves irradiating a drug with excitation light and observing the resulting fluorescence. For example, it can be useful in identifying lesions, not only for observing the affected area but also for supporting the surgeon's surgical procedure. Drugs have their own unique absorption spectra, and they fluoresce most efficiently when irradiated with excitation light of the same wavelength as the peak wavelength of their absorption spectrum.

[0012] Technological advancements in imaging devices and processors have made it possible to irradiate with white light during fluorescence observation, acquiring both drug fluorescence images (such as lesion images) and affected area images, and even superimposing them. Displaying the lesion location in real time with high accuracy enhances surgical support.

[0013] The medical light source devices described above are composed of various light sources that output white light for illumination and excitation light for drug excitation. The light from the light source device is guided to endoscopes, surgical microscopes, etc., via external light guides.

[0014] The optical system within the light source device includes optical elements such as lenses. When light passes through a lens, autofluorescence occurs, and this can potentially reach the drug. If the wavelength range of the autofluorescence overlaps with the wavelength range of the drug fluorescence, the autofluorescence becomes background noise, degrading the image quality (e.g., contrast) of the drug fluorescence image. This leads to a decrease in the accuracy of drug fluorescence observation.

[0015] At least some of the aforementioned problems are addressed by the disclosed technology. As will be detailed later, the materials and arrangement of the lenses within the light source device are modified.

[0016] 1. Figure 1 of the embodiment shows an example of the schematic configuration of the light source device 1 according to the embodiment. The light source device 1 is a light source device for medical use, and more specifically, a light source device for an endoscope or surgical microscope. Hereafter, the light source device 1 will be described as a light source device for an endoscope. To the extent that it is not inconsistent, an endoscope may be appropriately replaced with a surgical microscope.

[0017] Light source device 1 outputs light including white light and excitation light. In the figure, several light rays are schematically shown by arrows. The light output by light source device 1 is referred to as light Lo and illustrated. Light Lo from light source device 1 is incident on an external light guide 8. The external light guide 8 is connected to an endoscope. Light Lo is guided to the endoscope via the external light guide 8.

[0018] The light source device 1 includes a light source 2 and an optical system 3. Here, the external light guide 8 is considered an external component of the light source device 1. However, the external light guide 8 may also be a component of the light source device 1.

[0019] Light source 2 outputs light for obtaining white light and excitation light. The white light is for illumination and is used, for example, to illuminate the observation area (e.g., the affected area) of the endoscope. The excitation light is for drug excitation and is used, for example, to excite drugs present within the observation area of ​​the endoscope. Light source 2 may consist of multiple light sources, and some examples will be explained later with reference to Figures 7 to 9.

[0020] Various types of light sources may be used. For example, light source 2 may include at least one of a narrowband light source and a broadband light source. An example of a narrowband light source is a semiconductor laser such as an LD (Laser Diode). An example of a broadband light source is a lamp, LED, phosphor, etc. The light output by light source 2 is referred to as light Ls and is shown in the figure.

[0021] The optical system 3 guides light Ls from the light source 2 to the external light guide 8. This light corresponds to light Lo. If there are multiple light sources 2, the optical system 3 combines the light Ls from each light source 2 and guides it as light Lo to the external light guide 8. Light Lo is guided to the endoscope via the external light guide 8 and illuminates the observation range of the endoscope. The white light contained in light Lo illuminates the observation range, and the excitation light excites the drug present in the observation range.

[0022] Light Lo is light that includes white light and excitation light. White light is composed of blue light, green light, and red light. The wavelength range of the excitation light may be included in the wavelength range of white light. In this sense, light Lo can also be said to be white light including excitation light.

[0023] The excitation light may be blue light, with a peak wavelength of, for example, 440 nm to 480 nm. Unless otherwise specified, the excitation light is assumed to be such blue light.

[0024] The optical system 3 includes at least one lens, which is referred to as lens 4 and illustrated in the diagram. The material of lens 4 includes glass. Lens 4 may be a spherical lens or an aspherical lens. Optical elements other than lens 4 may also be included in the optical system 3, and some examples will be explained later with reference to Figures 7 to 9.

[0025] Here, when light Ls from light source 2 passes through lens 4, autofluorescence may occur. As mentioned earlier, autofluorescence can reduce the accuracy of drug fluorescence observation.

[0026] In this embodiment, the material of lens 4 is designed to suppress the generation of autofluorescence in lens 4. Specifically, lens 4 is configured to satisfy at least one of the following conditions C1 and C2. Condition C1: The yttrium oxide content is less than 10% by weight. Condition C2: The gadolinium oxide content is less than 1% by weight.

[0027] By satisfying at least one of the above conditions C1 and C2, the generation of autofluorescence in lens 4 is suppressed compared to the case where it does not. This will be explained with reference to Figures 2 to 5.

[0028] Figures 2 to 5 show examples of measurement results. Eight types of glass materials for lenses were selected from the viewpoint of refractive index, Abbe number, etc., and the autofluorescence generated when excitation light was irradiated was measured for each.

[0029] Figure 2 schematically shows the measurement method. A glass block was prepared, and the prepared glass block was irradiated with excitation light. The excitation light was blue LD light with a peak wavelength of 465 nm, and it was irradiated at an angle of 20 to 30 degrees relative to the glass block. The scattered light (corresponding to autofluorescence) generated at the incident surface of the excitation light in the glass block was measured spectroscopically using a spectrometer.

[0030] Figure 3 shows the spectrum of the measured light. The horizontal axis of the graph represents wavelength (nm). The vertical axis of the graph represents light intensity (in arbitrary units). The eight types of glass materials are referred to as glass material G1, glass material G2, glass material G3, glass material G4, glass material G5, glass material G6, glass material G7, and glass material G8. When not specifically distinguished, they are simply referred to as glass material or each glass material.

[0031] The light intensity is high at and around 465 nm, which can be presumed to be due to excitation light. The light intensity at longer wavelengths can be presumed to be due to autofluorescence, not excitation light. As shown in Figure 3, the light intensity due to autofluorescence differs depending on the glass material.

[0032] Figure 4 shows the comparison results. For each glass material, the normalized values ​​obtained by integrating the light intensity over a wavelength of 500 nm to 890 nm are shown. Specifically, the integrated light intensity values ​​for each glass material are normalized using the value of glass material G4, which has the smallest integrated light intensity value.

[0033] In particular, the integrated light intensity values ​​of glass material G1 and glass material G2 are considerably larger compared to the integrated light intensity values ​​of glass materials G3 to G8. In other words, autofluorescence is greater in lenses made of glass materials G1 and G2.

[0034] The difference in autofluorescence intensity among different glass materials is thought to be due to differences in their internal composition. Therefore, by using glass materials with compositions that avoid those of glass materials G1 and G2, the generation of autofluorescence in lens 4 can be suppressed.

[0035] Figure 5 shows the composition of each glass material. The names and chemical formulas of the materials that make up each glass material, as well as their content (weight %), are shown. As indicated by the thick border, glass materials G1 and G2 differ from glass materials G3 to G8 in that they contain yttrium oxide (Y2O3) and gadolinium oxide (Gd2O3).

[0036] Specifically, glass materials G1 and G2 contain 10 to 15% by weight of yttrium oxide. In contrast, glass materials G3 to G8 do not contain yttrium oxide. Furthermore, glass materials G1 and G2 contain 1 to 4% by weight of gadolinium oxide. In contrast, glass materials G3 to G8 do not contain gadolinium oxide.

[0037] Autofluorescence can be suppressed by limiting the yttrium oxide content or the gadolinium oxide content. Specifically, as described in conditions C1 and C2 above, using glass materials with a yttrium oxide content of less than 10% by weight or glass materials with a gadolinium oxide content of less than 1% by weight can suppress autofluorescence in lens 4, thereby suppressing a decrease in the accuracy of drug fluorescence observation. For example, the material of lens 4 may include at least one of glass materials G3 to G8.

[0038] Returning to Figure 1, in one embodiment, at least one lens 4 may include a lens positioned opposite the external light guide 8. This lens is located at the rearmost stage of the optical system 3 and focuses the light Lo onto the external light guide 8; it is also referred to as the rearmost lens 4-L.

[0039] Autofluorescence generated by the rear lens 4-L is more likely to reach the drug than autofluorescence generated by other lenses in the optical system 3. By suppressing the generation of autofluorescence in the rear lens 4-L, the effect of suppressing the reach of autofluorescence to the drug can be maximized.

[0040] In one embodiment, the distance from the rear lens 4-L to the external light guide 8 may be adjusted. This also helps to suppress the reach of autofluorescence generated by the rear lens 4-L to the drug. This will be explained with reference to Figure 6.

[0041] Figure 6 shows an example of the arrangement of the rear lens 4-L. The distance from the light output surface of the rear lens 4-L (the vertex of the convex portion in this example) to the light incident surface of the external light guide 8 is denoted as distance D and is shown in the figure. If the luminous intensity of autofluorescence at the light output surface of the rear lens 4-L is denoted as luminous intensity I (cd), and the illuminance of autofluorescence at the light incident surface of the external light guide 8 is denoted as illuminance E (lx), then E = I / D ２ As the distance D increases, the illuminance E decreases exponentially with respect to the luminous intensity I. For example, when the distance D doubles, the illuminance E becomes one-quarter of the luminous intensity I.

[0042] By increasing the distance D, the amount of autofluorescence incident on the external light guide 8 is reduced, which accordingly can suppress the arrival of autofluorescence at the drug. On the other hand, if the distance D becomes excessively large, the device will be upsized, and as the incident angle of light rays to the incident surface of the external light guide 8 decreases, performance-related effects such as a reduction in the irradiation range on the affected area may occur. From the viewpoint of these trade-offs, the distance D may be adjusted, for example, within a range of 7 mm or more and 23 mm or less. This makes it possible to balance the suppression of autofluorescence reaching the drug, the suppression of device upsizing, and the suppression of impact on performance.

[0043] A more specific configuration of the light source device 1 based on the technology described so far will be described with reference to FIGS. 7 to 9.

[0044] FIG. 7 is a diagram showing an example of a schematic configuration of the light source device 1. The light source device 1 includes a plurality of light sources 2, more specifically, three light sources 2 in this example. To distinguish each light source 2, they are illustrated and referred to as light source 2-A, light source 2-B, and light source 2-C. When these are not particularly distinguished, they are simply referred to as the light source 2 or each light source 2.

[0045] The light Ls output from the light source 2-A is illustrated and referred to as light Ls-A. The light Ls output from the light source 2-B is illustrated and referred to as light Ls-B. The light Ls output from the light source 2-C is illustrated and referred to as light Ls-C. When these are not particularly distinguished, they are simply referred to as the light Ls or each light Ls.

[0046] The optical system 3 includes a plurality of lenses 4 and a plurality of mirrors 5.

[0047] As the plurality of lenses 4, in addition to the rear-stage lens 4-L, there is also a lens 4 provided to face the light source 2. This lens 4 is the most front-stage lens among the lenses in the optical system 3, and is illustrated and referred to as front-stage lens 4-F.

[0048] In the example shown in FIG. 7, there are three front-stage lenses 4-F corresponding to the three light sources 2. Similarly to the rear-stage lens 4-L, the front-stage lens 4-F may also be configured to satisfy at least one of the condition C1 and condition C2 described above.

[0049] Multiple mirrors 5 are provided between the front lens 4-F and the rear lens 4-L, and are multiplexing elements that combine the light Ls from each light source 2 and guide it to the rear lens 4-L. Examples of multiplexing include wavelength multiplexing and polarization multiplexing.

[0050] Furthermore, when we say that one optical element is placed between two other optical elements, it should be understood that the optical element is placed on the optical path between the two optical elements (for example, on the optical axis).

[0051] There are three mirrors 5 corresponding to the three light sources 2, and they are positioned on the opposite side of the preceding lens 4-F from the corresponding light source 2. The mirror 5 corresponding to light source 2-A is referred to as mirror 5-A and is shown in the illustration. The mirror 5 corresponding to light source 2-B is referred to as mirror 5-B and is shown in the illustration. The mirror 5 corresponding to light source 2-C is referred to as mirror 5-C and is shown in the illustration. When not specifically distinguished, they are simply referred to as mirror 5 or each mirror 5. Mirror 5 may be a total internal reflection mirror or a dichroic mirror.

[0052] Mirror 5-C is a total internal reflection mirror. Mirror 5-C reflects the light Ls-C from light source 2-C toward the subsequent lens 4-L.

[0053] Mirror 5-B is a dichroic mirror. Mirror 5-B reflects light Ls-B from light source 2-B toward the subsequent lens 4-L, and also allows light Ls-C from mirror 5-C to pass toward the subsequent lens 4-L.

[0054] Mirror 5-A is a dichroic mirror. Mirror 5-A reflects light Ls-A from light source 2-A toward the subsequent lens 4-L, and also allows light Ls-B and Ls-C from mirror 5-B to pass toward the subsequent lens 4-L.

[0055] Mirrors 5-A, 5-B, and 5-C combine the light Ls-A from light source 2-A, Ls-B from light source 2-B, and Ls-C from light source 2-C, and guide them to the subsequent lens 4-L. The subsequent lens 4-L focuses the combined light Ls-A, Ls-B, and Ls-C as light Lo onto the external light guide 8.

[0056] As mentioned earlier, light source 2 may be a broadband light source or a narrowband light source. Various light sources may be used as light source 2-A, light source 2-B, and light source 2-C. For example, all three light sources 2 may be broadband light sources. One light source 2 (e.g., light source 2-A) may be a narrowband light source, and the remaining two light sources 2 (e.g., light sources 2-B and 2-C) may be broadband light sources. All three light sources 2 may be narrowband light sources.

[0057] Figure 8 shows an example of the schematic configuration of the light source device 1. Two light sources 2 are shown as multiple light sources 2, each indicated by a reference numeral. The first light source is referred to as light source 2-1 and shown. The second light source is referred to as light source 2-2 and shown. Unless otherwise specified, they are simply referred to as light source 2 or each light source 2.

[0058] The light Ls output by light source 2-1 is referred to as light Ls-1 and is shown in the figure. The light Ls output by light source 2-2 is referred to as light Ls-2 and is shown in the figure. Unless otherwise specified, these are simply called light Ls or each light Ls.

[0059] The optical system 3 includes multiple lenses 4, multiple mirrors 5, multiple diffusers 6, and an internal light guide 7.

[0060] In addition to the front lens 4-F and the rear lens 4-L, a lens 4 positioned between them is also shown as part of the multiple lenses 4. This lens 4 is located in the middle of the optical system 3 and is referred to as the middle lens 4-M and shown in the diagram. The middle lens 4-M, like the rear lens 4-L, may be configured to satisfy at least one of the conditions C1 and C2 described above.

[0061] There are two front-end lenses 4-F. The front-end lens corresponding to light source 2-1 (the first front-end lens) is referred to as front-end lens 4-F-1 and is shown in the illustration. The front-end lens corresponding to light source 2-2 (the second front-end lens) is referred to as front-end lens 4-F-2 and is shown in the illustration. When these are not distinguished, they are simply referred to as front-end lens 4-F or each front-end lens 4-F.

[0062] There are two intermediate lenses 4-M. One intermediate lens 4-M is referred to as intermediate lens 4-M-1 and is shown in the illustration. The other intermediate lens 4-M is referred to as intermediate lens 4-M-2 and is shown in the illustration. Unless otherwise specified, they are simply referred to as intermediate lens 4-M or each intermediate lens 4-M.

[0063] There are two mirrors 5 corresponding to the two light sources 2. The mirror corresponding to light source 2-1 (the first mirror) is referred to as mirror 5-1 and is illustrated in the diagram. The mirror corresponding to light source 2-2 (the second mirror) is referred to as mirror 5-2 and is illustrated in the diagram.

[0064] Mirror 5-1 is a total internal reflection mirror. Mirror 5-1 reflects light Ls-1 from light source 2-1 toward the subsequent lens 4-L.

[0065] Mirror 5-2 is a dichroic mirror. Mirror 5-2 reflects light Ls-2 from light source 2-2 toward the subsequent lens 4-L, and also allows light Ls-1 from mirror 5-1 to pass toward the subsequent lens 4-L.

[0066] There are two diffusers 6. One diffuser (the first diffuser) is referred to as diffuser 6-1 and is shown in the figure. The other diffuser (the second diffuser) is referred to as diffuser 6-2 and is shown in the figure. When not specifically distinguishing between them, they are simply referred to as diffuser 6 or each diffuser 6.

[0067] The internal light guide 7 is provided between the front lens 4-F-1 and the rear lens 4-L, more specifically between the diffuser plate 6-1 and the diffuser plate 6-2 in this example. The internal light guide 7 is, for example, a rod, an optical fiber, etc.

[0068] The internal light guide 7 can function as a light source that outputs light Ls-1 from its light output surface. In one embodiment, the size of the light output surface of the internal light guide 7 may be the same as the size of the light output surface of the light source 2-2 that outputs light Ls-2. Examples of size include shape (e.g., rectangular), dimensions, area, etc. By matching the sizes of the light output surfaces of the internal light guide 7 and the light source 2-2, it becomes easier to match the cross-sectional sizes of light Ls-1 and light Ls-2 that constitute light Lo, which is combined by the mirror 5-2 and incident on the external light guide 8. Optical elements such as the intermediate lens 4-M-2 and the front lens 4-F-2 may be designed so that the image sizes of light Ls-1 and light Ls-2 are approximately the same.

[0069] From mirror 5-1 toward mirror 5-2, the intermediate lens 4-M-1, diffuser plate 6-1, internal light guide 7, diffuser plate 6-2, and intermediate lens 4-M-1 are arranged in this order. Light Ls-1 from mirror 5-1 enters the internal light guide 7 via the intermediate lens 4-M-1 and diffuser plate 6-1. Light Ls-1 propagates through the internal light guide 7 and is output from the internal light guide 7. This light Ls-1 enters mirror 5-2 via the diffuser plate 6-2 and intermediate lens 4-M-2.

[0070] The diffuser plate 6-1 is a conversion element that diffuses (directs in various directions) the incident light and outputs it. The diffuser plate 6-1 is placed between the front lens 4-F-1 and the internal light guide 7 so that the light from the front lens 4-F-1, more specifically the light from the middle lens 4-M-1 in this example, is incident at an angle with respect to the extension direction of the internal light guide 7.

[0071] By providing the diffuser plate 6-1, the numerical aperture (NA) of the light rays incident on the internal light guide 7 can be increased. This allows the length of the internal light guide 7 to be reduced. Note that other conversion elements besides the diffuser plate 6-1 may also be used. Examples of other conversion elements include fly-eye lenses and microlens arrays.

[0072] The intermediate lens 4-M-2 guides the light Ls from the diffuser plate 6-2 to the mirror 5-2. The mirror 5-2 reflects the light Ls-2 from the light source 2-2 toward the rear lens 4-L, and also allows the light Ls-1 from the intermediate lens 4-M-2 to pass toward the rear lens 4-L. The light Ls-1 and light Ls-2 are combined and guided toward the rear lens 4-L.

[0073] In one embodiment, the light source 2-1 described above may be a plurality of light sources. The internal light guide 7 may integrate (combine, combine) the light from the plurality of light sources 2-1. In this case, the internal light guide 7 may also be called a rod integrator or the like. This will be explained with reference to Figure 9.

[0074] Figure 9 shows an example of the schematic configuration of the light source device 1. There are multiple light sources 2-1, more specifically three light sources 2-1 in this example. Corresponding to them are three front-stage lenses 4-F-1 and three mirrors 5-1. Light from each of the three light sources 2-1 is reflected by the corresponding mirror 5-1, passes through the middle-stage lens 4-M-1 and diffuser plate 6-1, and enters the internal light guide 7.

[0075] The three beams of light that enter the internal light guide 7 propagate through the internal light guide 7, are integrated, and then output from the internal light guide 7. This light, as light Ls-1, passes through the diffuser plate 6-2 and the intermediate lens 4-M-2 and enters the mirror 5-2.

[0076] For example, in the light source device 1 with various configurations as shown in Figures 7 to 9 above, the generation of autofluorescence at the lens 4 can be suppressed, thereby suppressing a decrease in the accuracy of drug fluorescence observation.

[0077] Figures 10 and 11 show examples of measurements. They show the measurement environment and results for autofluorescence when using glass material G1 and glass material G3, as described earlier.

[0078] As shown in Figure 10, the external light guide 8 is in the form of a cable and is connected to the endoscope 81 (a rigid endoscope in this example). Light Lo from the light source device 1 is output from the tip of the endoscope 81 and irradiates the screen 9. The part of the screen 9 irradiated with light Lo corresponds to the observation range of the endoscope 81 (the affected area, etc.).

[0079] An imaging device 82 and a filter 83 are provided at the proximal end (the part opposite the tip) of the endoscope 81. The filter 83 cuts out the excitation light. Light from the screen 9 enters the imaging device 82 via the filter 83 and is detected. In this way, the autofluorescence of the light Lo that reaches the screen 9, i.e., the observation range of the endoscope 81, is measured.

[0080] Figure 11 shows the measurement results. By using glass material G3 as the lens material, the amount of autofluorescence is significantly reduced compared to when glass material G1 is used. This suppresses the decrease in accuracy of drug fluorescence observation that may occur due to autofluorescence.

[0081] 2. The technologies described above can be identified, for example, as follows: One of the disclosed technologies is a light source device 1. As described with reference to Figures 1 to 9, the light source device 1 is a medical light source device. The light source device 1 comprises a light source 2 that outputs light Ls for obtaining white light for illumination and excitation light for drug excitation, and an optical system 3 that guides the light Ls from the light source 2 to an external light guide 8. The optical system 3 includes at least one lens 4 (e.g., a spherical lens, an aspherical lens, etc.), and at least one of the following conditions C1, which is that the yttrium oxide content is less than 10% by weight, and C2, which is that the gadolinium oxide content is less than 1% by weight.

[0082] According to the light source device 1 described above, the generation of autofluorescence at the lens 4 can be suppressed. Therefore, a decrease in the accuracy of drug fluorescence observation can be suppressed.

[0083] At least one lens 4 may satisfy both conditions C1 and C2. This can further enhance the effect of suppressing the generation of autofluorescence.

[0084] As explained with reference to Figures 1 and 5, the material of at least one lens 4 can be a glass material that satisfies the above conditions C1 and C2 (for example, at least one of glass materials G3 to G8), thereby suppressing the generation of autofluorescence in the lens 4.

[0085] As explained with reference to Figures 6 to 9, at least one lens 4 includes a subsequent lens 4-L positioned opposite the external light guide 8, and the subsequent lens 4-L may satisfy at least one of conditions C1 and C2. This maximizes the effect of suppressing the arrival of autofluorescence to the drug.

[0086] As explained with reference to Figure 6, the distance D between the rear lens 4-L and the external light guide 8 may be between 7 mm and 23 mm. This further suppresses the arrival of autofluorescence at the drug while suppressing the increase in the size of the device and minimizing the impact on performance.

[0087] As explained with reference to Figure 1, etc., white light includes blue light, green light, and red light, and the excitation light includes blue light, and the peak wavelength of the excitation light may be between 440 nm and 480 nm. For example, in a light source device 1 that outputs such white light and excitation light, the generation of autofluorescence at the lens 4 can be suppressed.

[0088] As explained with reference to Figure 1, the light source 2 includes at least one of a narrowband light source and a broadband light source, the narrowband light source includes a semiconductor laser, and the broadband light source may include at least one of a lamp, an LED, and a phosphor. The light source 2 includes a blue light source, and the blue light source may be a narrowband light source including a semiconductor laser. For example, in a light source device 1 equipped with a light source 2 of such various configurations, the generation of autofluorescence at the lens 4 can be suppressed.

[0089] As explained with reference to Figures 7 to 9, at least one lens 4 comprises a front lens 4-F positioned facing the light source 2 and a rear lens 4-L positioned facing the external light guide 8, and both the front lens 4-F and the rear lens 4-L may satisfy at least one of conditions C1 and C2. For example, when multiple lenses 4 exist in this manner, the generation of autofluorescence in each lens 4 can be suppressed.

[0090] As explained with reference to Figures 8 and 9, the light source 2 is a plurality of light sources, and at least one lens 4 includes a downstream lens 4-L provided to face the external light guide 8, a downstream lens 4-F-1 (first downstream lens) provided to face the light source 2-1 (first light source), and a downstream lens 4-F-2 (second downstream lens) provided to face the light source 2-2 (second light source). The optical system 3 may include an internal light guide 7 (e.g., a rod, optical fiber) provided between the downstream lens 4-F-1 and the upstream lens 4-L, and a mirror 5-2 (multiplexing element, e.g., dichroic mirror) that combines the light Ls-1 from the internal light guide 7 and the light Ls-2 from the downstream lens 4-F-2 and guides them to the downstream lens 4-L. For example, even in a light source device 1 equipped with such an internal light guide 7, the generation of autofluorescence at the lens 4 can be suppressed. The size of the light output surface of the internal light guide 7 may be the same as the size of the light output surface of the light source 2-2. This makes it easier to align the cross-sectional sizes of the light sources Ls-1 and Ls-2 that constitute the light Lo incident on the external light guide 8. As explained with reference to Figure 9, the light source 2-1 may be a plurality of light sources 2-1, and the internal light guide 7 may integrate the light from each of the plurality of light sources 2-1. The internal light guide 7 can be used as an integrator (for example, a rod integrator).

[0091] As explained with reference to Figures 8 and 9, the optical system 3 may include a diffuser plate 6-1 (an example of a conversion element) provided between the front lens 4-F-1 and the internal light guide 7 so that the light Ls-1 from the front lens 4-F-1 is incident on the internal light guide 7 at an angle. This increases the numerical aperture (NA) of the light rays incident on the internal light guide 7, thereby reducing the length of the internal light guide 7. Conversion elements other than the diffuser plate 6-1, such as a fly eye or a microlens array, may also be used.

[0092] As explained with reference to Figures 1 and 10, the external light guide 8 may be connected to the endoscope 81 or surgical microscope. This can suppress a decrease in the accuracy of drug fluorescence observation using the endoscope 81 or surgical microscope.

[0093] 3. Application Examples The light source device 1 described above can be used, for example, as a component of an endoscope system. This will be explained with reference to Figures 12 to 14.

[0094] Figure 12 shows an example of the schematic configuration of an endoscope system 11. The endoscope system 11 includes an endoscope 12, a light source device 13, a CCU (Camera Control Unit) 14, a display device 15, a treatment device 16, a recording device 17, and an output device 18.

[0095] The endoscope 12 captures images of the inside of a subject's body by inserting its tip into the subject's body. The endoscope 12 comprises a flexible, elongated insertion section 121, an operation section 122 connected to the proximal end of the insertion section 121 that receives various operation signals, and a universal cord 123 that houses various cables from the operation section 122. The endoscope 12 is also referred to as an endoscope scope.

[0096] The insertion section 121 comprises a tip section 124, a curved section 125, and a flexible section 126. The tip section 124 includes an imaging section 1243 having an image sensor configured in which pixels that perform photoelectric conversion of received light to generate pixel signals are arranged in a two-dimensional matrix. The curved section 125 is configured to be flexible, such as by having multiple curved portions. The flexible section 126 is connected to the base end of the curved section 125 and is configured as a long, flexible length. This insertion section 121 is inserted into the body cavity of a subject and images a subject such as biological tissue located in a position where external light cannot reach using the image sensor. In addition to the imaging section 1243, the tip section 124 is also equipped with an illumination section 1242 that irradiates the subject with illumination light for imaging. Furthermore, the insertion section 121 may also be equipped with a forceps port 1244 for inserting a treatment instrument 162, a water inlet 1245 for supplying water into the subject, and an air inlet 1246 for supplying air into the subject.

[0097] The operating unit 122 operates the insertion unit 121. The operating unit 122 includes a curved knob 1221, a treatment instrument insertion unit 1222, and a plurality of switches 1223. The curved knob 1221 curves the curved unit 125 in the vertical and horizontal directions. The treatment instrument insertion unit 1222 inserts the treatment instrument 162 into the body cavity of the subject. The switches 1223 are operation input units that input operation instruction signals for peripheral devices.

[0098] The treatment device 16 includes a treatment instrument operating section 161 and a flexible treatment instrument 162 extending from the treatment instrument operating section 161. Examples of treatment instruments 162 include a therapeutic light irradiation device, biopsy forceps, an electrosurgical unit, and an examination probe. The treatment instrument operating section 161 operates the treatment instrument 162. The treatment instrument 162 is inserted through a treatment instrument insertion section 1222 and emerges from a forceps channel 1244 at its tip 124.

[0099] The universal cord 123 incorporates at least an optical fiber 134 for transmitting light to the illumination unit 1242 and a bundled cable including the signal lines of the imaging unit 1243. The universal cord 123 branches at the end opposite to the side connected to the operation unit 122. The optical fiber 134 of the universal cord 123 is connected to the light source device 13. The bundled cable of the universal cord 123 is connected to the CCU 14. In this embodiment, it is described as transmitting electrical signals using signal lines, but it may also transmit optical signals, or signals may be transmitted between the endoscope 12 and the CCU 14 by wireless communication.

[0100] The light source device 13 emits light for illumination. The light emitted by the light source device 13 is transmitted to the illumination unit 1242 via the optical fiber 134. The optical fiber 134 is also called a light guide.

[0101] The CCU 14 is a control device that comprehensively controls the connected endoscope 12 and light source device 13. The CCU 14 may also comprehensively control the connected display device 15, recording device 17, and output device 18. For example, the CCU 14 controls the irradiation timing, irradiation intensity, and type of light source of the light source device 13. The CCU 14 also performs image processing such as development processing (e.g., demosaicing) and correction processing on the pixel signals output from the endoscope 12, and outputs the processed pixel signals (e.g., images) to external devices such as the display device 15. The CCU 14 also transmits control signals to the endoscope 12 to control its operation. These control signals are, for example, information regarding imaging conditions such as the magnification and focal length of the imaging unit. The CCU 14 may also have an image downconversion function and be configured to simultaneously output high-resolution (e.g., 4K) images to the display device 15 and low-resolution (e.g., HD) images to the recording device 17. Furthermore, the CCU 14 and the light source device 13 may be integrated and housed in the same housing. Alternatively, the CCU 14 and the light source device 13 may have interfaces that can connect to both rigid and flexible endoscopes, and the necessary functions for both rigid and flexible endoscopes may be arranged within a common housing.

[0102] The display device 15 is a device capable of displaying images, such as a display monitor. The display device 15 displays a display image based on pixel signals acquired from the CCU 14. The display device 15 may also function as an input device that enables eye-tracking, voice recognition, and gesture-based instruction input by having a camera and microphone.

[0103] The recording device 17 is a device that records pixel signals (e.g., images) acquired from the CCU 14, and is, for example, a recorder. The recording device 17 records the images acquired from the CCU 14 onto an HDD, SSD, or optical disc. The recording device 17 may be connected to a hospital network and made accessible from equipment outside the operating room. The recording device 17 may also have an image down-conversion or up-conversion function.

[0104] The output device 18 is a device that outputs information acquired from the CCU 14, and is, for example, a printer. The output device 18 prints a print image on paper based on the pixel signals acquired from the CCU 14.

[0105] The right side of Figure 12 shows a schematic, magnified view of the tip 124. The end face of the tip 124 can be fitted with an illumination unit 1242, an imaging unit 1243, a forceps channel 1244, a water inlet 1245, and an air inlet 1246. The tip 124 in the figure shows an example where three illumination units 1242 are fitted. These illumination units 1242 are preferably positioned to surround the imaging unit 1243, as this suppresses the generation of shadows on the subject. Cover glass can be placed over the illumination units 1242 for protection. In addition to the image sensor 1248 (Figure 13, described later), the imaging unit 1243 is fitted with an optical system 1249, such as a lens that collects light from the subject.

[0106] Water supplied from the water inlet 1245 can be used to clean the surface of the imaging unit 1243 and to wash away foreign matter to clarify the field of view. Air supplied from the air inlet 1246 can be used to inflate the affected organ to secure the field of view.

[0107] Furthermore, the forceps channel 1244 can also be used for aspirating mucus or other fluids.

[0108] Figure 13 is a block diagram showing an example of the schematic configuration of an endoscope system 11. Several components of the endoscope 12, light source device 13, CCU 14, display device 15, and treatment device 16 are shown.

[0109] The curved knob 1221 of the operating section 122 pushes and pulls the guide wire 1224 located inside the insertion section 121, allowing the tip section 124 to move up, down, left, and right.

[0110] The light source device 13 comprises a light source 131, an illumination control unit 132, and an optical system 133. The light source 131 emits illumination light based on the control of the illumination control unit 132. The light source 131 in the figure has an LD 1311 and a phosphor 1312. The LD 1311 emits laser light. For example, the LD 1311 emits a blue laser. The phosphor 1312 converts the wavelength of the laser light from the LD 1311. The phosphor 1312 emits fluorescence when excited by the laser light, and generates light with a different wavelength from the laser light that is the excitation light. For example, a material that generates yellow fluorescence when excited by a blue laser can be used for the phosphor 1312. A portion of the blue laser light from the LD 1311 is converted into yellow light by the phosphor 1312. These blue laser light and yellow light are mixed to generate white light. This white light is emitted from the light source 131. Note that the configuration of the light source device 13 is not limited to this example. For example, the light source 131 can consist only of an LD 1311, with a phosphor 312 placed in the illumination section 1242 of the tip 124. Alternatively, a light-emitting diode (LED) or a xenon lamp can be used as the light source 131.

[0111] The optical system 133 focuses the light emitted from the light source 131 onto the end of the optical fiber 134. The other end of the optical fiber 134 reaches the illumination section 1242 of the tip 124, and the light emitted from the light source device 13 is transmitted to the tip 124 via the optical fiber 134 and emitted from the end face. In this case, the end of the optical fiber 134 constitutes the illumination section 1242.

[0112] The imaging unit 1243 comprises an image sensor 1248 and an optical system 1249. The optical system 1249 guides light from the subject to the image sensor 1248. The optical system 1249 can be composed of, for example, multiple lenses. The image sensor 1248 acquires reflected light from the subject that has been irradiated from the illumination unit 1242, performs imaging, generates a pixel signal, and outputs it. For example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor can be used for the image sensor 1248. The image sensor 1248 performs imaging based on control signals from the CCU 14. The image sensor 1248 also outputs the generated pixel signal to the CCU 14. These control signals and pixel signals are transmitted by a bundled cable located in the insertion unit 121. The CCU 14 generates an image from the image sensor 1248 based on the pixel signal and outputs it to the display device 15.

[0113] The treatment device 16 comprises a treatment instrument operating section 161 and a treatment instrument 162. The treatment instrument 162 is inserted into the insertion section 121, and its end protrudes from the forceps channel 1244 of the tip section 124. A water inlet 1245 and an air inlet 1246 are further arranged at the tip section 124.

[0114] Figure 14 is a block diagram showing an example of the schematic configuration of the CCU 14. The CCU 14 is an information processing device having an FPGA 1401, a CPU 1402, a RAM 1403, a ROM 1404, a GPU 1405, and an I / F 1406.

[0115] <Special Light Observation> The light source device 13 may have a light source capable of emitting special light used for special light observation, in addition to the light source that emits normal light used for normal light observation. Here, special light is light in a predetermined wavelength band different from the normal light used for normal light observation, and is, for example, near-infrared light (light with a wavelength of 760 nm or more), infrared light, blue light, or ultraviolet light. Normal light is, for example, white light or green light. In observation using light of a specific narrow band wavelength, which is a type of special light observation, by alternately irradiating with blue light and green light, it is possible to take high-contrast images of predetermined tissues such as blood vessels on the surface of mucous membranes by utilizing the wavelength dependence of light absorption in body tissues.

[0116] Furthermore, in fluorescence observation, a type of special light observation, excitation light is irradiated onto a drug injected into body tissue to excite it, and a fluorescence image is obtained by receiving the fluorescence emitted by the body tissue or the labeling drug. This makes it easier for the operator to visualize body tissues and other areas that are difficult to see with normal light. For example, in fluorescence observation using infrared light, infrared light with an excitation wavelength range is irradiated onto a drug such as indocyanine green (ICG) injected into body tissue, and the fluorescence of the drug is received, making it easier to visualize the structure of the body tissue and the affected area.

[0117] Furthermore, in fluorescence observation, a drug (e.g., 5-ALA) that is excited by special light in the blue light wavelength band and emits fluorescence in the red light wavelength band may be used. In this case, the light source device 13 sets the type of irradiation light by controlling the CCU 14. The CCU 14 may have a mode in which normal light observation and special light observation are performed alternately by controlling the light source device 13 and the endoscope 12. In this case, it is preferable to superimpose information based on the pixel signal obtained in special light observation onto the pixel signal obtained in normal light observation. Also, special light observation may involve irradiating the affected area with amber-colored light, which has the characteristic of being easily absorbed by hemoglobin in the blood, along with green light and red light, to make blood vessels and bleeding areas in deeper parts such as mucosa more visible and reduce the risk of bleeding. Furthermore, special light observation may be multispectral observation utilizing hyperspectral spectroscopy. In addition, photodynamic therapy may be combined with special light observation.

[0118] Furthermore, the CCU14 may have a function to perform image processing that optimizes three elements—structure, color tone, and brightness—in images of the mucosal surface, and emphasizes changes in the color tone and structure of the image.

[0119] Furthermore, the light source device 13 may include a light source that emits short-wavelength laser light (for example, blue laser light). The CCU 14 can generate an image of the affected area by changing the emission intensity ratio of this blue laser light and the white light from the light source 131. The CCU 14 may also have a function to perform image processing on the image obtained with the blue laser light to generate an image suitable for observing blood vessels, surface structures, etc. The CCU 14 may also have a function to acquire an image obtained with white light and an image obtained with a blue-violet laser, and to apply color enhancement technology to generate an image that emphasizes the difference in color tones.

[0120] <Distance Measurement> Distance measurement can also be performed using the image sensor 1248 of the endoscope 12 to measure the distance to the affected area of ​​the subject. For example, based on the measured distance between the endoscope and the affected area, it is possible to detect the size of the affected area from the captured image. Distance measurement can be performed by normalizing the brightness of the image of the subject to generate a normalized brightness image, and then generating depth information from the normalized brightness image using a learning model that has learned the correlation between depth and brightness. Furthermore, the three-dimensional shape of the affected area can also be obtained using this depth information.

[0121] Distance can also be measured using the Time of Flight (ToF) method. For example, a range-measuring light source can be placed at the tip 124, and the reflected light from the light source reflected by the affected area can be detected by the image sensor 1248. By measuring the time from the emission of light from the range-measuring light source to the detection of the reflected light, the distance to the affected area can be measured. In this case, the CCU 14 can measure the time from the emission of light from the light source to the detection of the reflected light and calculate the distance. Furthermore, this range measurement can be used to generate a depth map or distance image of the subject, making it possible to obtain the three-dimensional shape of the affected area.

[0122] <AI Diagnosis> The AI ​​can also analyze images taken by the endoscope 12. The results of this analysis can be displayed on the display device 15. For example, if the AI ​​detects a candidate lesion such as a polyp or cancer from the image, the CCU 14 can superimpose a frame indicating the detection location onto the image and display it on the display device 15. Since the lesion location is displayed in real time, convenience can be improved. The AI ​​can also detect inflammatory activity in the affected area and detect an evaluation value of inflammation. The CCU 14 can display the detection results on the display device 15. Note that image analysis may be performed by an analysis device other than the CCU 14.

[0123] <Cloud Usage> It is also possible to perform the image processing and AI-based diagnosis described above in the cloud and send the analysis results to the CCU 14. In this case, the endoscopy system 11 is connected to the cloud via the network.

[0124] Each component of the illustrated device is a functional concept and does not necessarily have to be physically configured as shown. In other words, the specific forms of distribution and integration of each device are not limited to those shown, and all or part of them can be functionally or physically distributed and integrated in any unit according to various loads, usage conditions, etc. Furthermore, this distribution and integration configuration may be performed dynamically.

[0125] A system refers to a collection of multiple components (devices, modules, parts, etc.), regardless of whether all components reside in the same enclosure. Therefore, multiple devices housed in separate enclosures and connected via a network, as well as a single device containing multiple modules within a single enclosure, are both considered systems.

[0126] Alternatively, a cloud computing configuration may be adopted in which, for example, a single function is shared and processed collaboratively by multiple devices via a network.

[0127] As the light source device 13, which is a component of the above-described endoscope system 11 (Figures 12 to 14), the light source device 1 according to the previously described embodiment may be used.

[0128] 4. Endoscopic systems for different application examples will be explained with reference to Figures 15 to 17.

[0129] <Endoscopic System> An example of an endoscopic system will be explained using Figures 15 and 16. Figure 15 is a diagram showing an example of the schematic configuration of an endoscopic system 5000 to which the technology relating to this disclosure can be applied. Figure 16 is a diagram showing an example of the configuration of an endoscope 5001 and a CCU (Camera Control Unit) 5039. Figure 15 illustrates a surgeon (e.g., a physician) 5067, who is a participant in the surgery, performing surgery on a patient 5071 on a patient bed 5069 using the endoscopic system 5000. As shown in Figure 15, the endoscopic system 5000 consists of an endoscope 5001, which is a medical imaging device, a CCU 5039, a light source device 5043, a recording device 5053, an output device 5055, and a support device 5027 that supports the endoscope 5001.

[0130] In endoscopic surgery, an insertion aid called a trocca 5025 is inserted into the patient 5071. Then, via the trocca 5025, the scope 5003 connected to the endoscope 5001 and surgical instruments 5021 are inserted into the body of the patient 5071. The surgical instruments 5021 include, for example, energy devices such as electrosurgical units or forceps.

[0131] Surgical images, which are medical images of the inside of the patient's body (5071) taken by the endoscope (5001), are displayed on the display device (5041). The surgeon (5067) performs the procedure on the surgical target using the surgical instruments (5021) while viewing the surgical images displayed on the display device (5041). Note that the medical images are not limited to surgical images; they may also be diagnostic images taken during the diagnosis.

[0132] <Endoscope> The endoscope 5001 is an imaging unit that images the inside of the patient 5071's body. For example, as shown in Figure 16, it is a camera 5005 that includes a focusing optical system 50051 that focuses incident light, a zoom optical system 50052 that changes the focal length of the imaging unit to enable optical zoom, a focusing optical system 50053 that changes the focal length of the imaging unit to enable focus adjustment, and a light-receiving element 50054. The endoscope 5001 generates a pixel signal by focusing light onto the light-receiving element 50054 via the connected scope 5003 and outputs the pixel signal to the CCU 5039 through a transmission system. The scope 5003 has an objective lens at its tip and is an insertion unit that guides light from the connected light source device 5043 into the patient 5071's body. The scope 5003 is, for example, a rigid scope in the case of a rigid endoscope, and a flexible scope in the case of a flexible endoscope. The scope 5003 may be a straight-viewing endoscope or an oblique-viewing endoscope. Furthermore, the pixel signal can be any signal based on the signal output from the pixel, such as a RAW signal or an image signal. Alternatively, the transmission system connecting the endoscope 5001 and the CCU 5039 may be equipped with memory to store parameters related to the endoscope 5001 and the CCU 5039. The memory may be located, for example, at the connection point of the transmission system or on the cable. For example, the factory settings of the endoscope 5001 and parameters that change during power-up may be stored in the transmission system's memory, and the operation of the endoscope may be modified based on the parameters read from the memory. The endoscope and transmission system may also be referred to as a set. The photodetector 50054 is a sensor that converts received light into a pixel signal, and is, for example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor. Preferably, the photodetector 50054 is a color image sensor having a Bayer array. Furthermore, the light-receiving element 50054 is preferably an image sensor having a number of pixels corresponding to a resolution of, for example, 4K (3840 horizontal pixels × 2160 vertical pixels), 8K (7680 horizontal pixels × 4320 vertical pixels), or square 4K (3840 or more horizontal pixels × 3840 or more vertical pixels). The light-receiving element 50054 may be a single sensor chip or multiple sensor chips.For example, a prism may be provided to separate the incident light into predetermined wavelength bands, and each wavelength band may be imaged by a different photodetector. Alternatively, multiple photodetectors may be provided for stereoscopic viewing. The photodetector 50054 may be a sensor that includes an image processing circuit within its chip structure, or it may be a Time of Flight (ToF) sensor. The transmission system may be, for example, an optical fiber cable or wireless transmission. Wireless transmission is only required if the pixel signals generated by the endoscope 5001 can be transmitted. For example, the endoscope 5001 and the CCU 5039 may be wirelessly connected, or the endoscope 5001 and the CCU 5039 may be connected via a base station in the operating room. In this case, the endoscope 5001 may simultaneously transmit not only the pixel signals but also information related to the pixel signals (for example, the processing priority of the pixel signals or synchronization signals). The endoscope may integrate the scope and camera, or a photodetector may be provided at the tip of the scope.

[0133] <CCU (Camera Control Unit)> The CCU 5039 is a control device that comprehensively controls the connected endoscope 5001 and light source device 5043. For example, as shown in Figure 16, it is an information processing device having an FPGA 50391, CPU 50392, RAM 50393, ROM 50394, GPU 50395, and I / F 50396. The CCU 5039 may also comprehensively control the connected display device 5041, recording device 5053, and output device 5055. For example, the CCU 5039 controls the irradiation timing, irradiation intensity, and type of light source of the light source device 5043. The CCU 5039 also performs image processing such as development processing (e.g., demosaicing) and correction processing on the pixel signals output from the endoscope 5001, and outputs the processed pixel signals (e.g., images) to an external device such as the display device 5041. Furthermore, the CCU 5039 transmits control signals to the endoscope 5001 to control its operation. The control signals include, for example, information regarding imaging conditions such as the magnification and focal length of the imaging unit. The CCU 5039 may also have an image downconversion function and be configured to simultaneously output high-resolution (e.g., 4K) images to the display device 5041 and low-resolution (e.g., HD) images to the recording device 5053.

[0134] Furthermore, the CCU 5039 may be connected to external devices (e.g., recording devices, display devices, output devices, support devices) via an IP converter that converts signals to a predetermined communication protocol (e.g., IP (Internet Protocol)). The connection between the IP converter and the external devices may consist of a wired network, or part or all of the network may be constructed as a wireless network. For example, the IP converter on the CCU 5039 side may have a wireless communication function and transmit the received video to an IP switcher or output-side IP converter via a wireless communication network such as a fifth-generation mobile communication system (5G) or a sixth-generation mobile communication system (6G).

[0135] <Light Source Device> The light source device 5043 is a device capable of irradiating light in a predetermined wavelength band, and includes, for example, a plurality of light sources and a light source optical system that guides the light from the plurality of light sources. The light sources are, for example, xenon lamps, LED light sources, and LD light sources. The light source device 5043 has, for example, LED light sources corresponding to each of the three primary colors R, G, and B, and emits white light by controlling the output intensity and output timing of each light source. In addition, the light source device 5043 may have a light source capable of irradiating special light used for special light observation, separate from the light source that irradiates normal light used for normal light observation. Special light is light in a predetermined wavelength band different from the normal light used for normal light observation, and is, for example, near-infrared light (light with a wavelength of 760 nm or more), infrared light, blue light, or ultraviolet light. Normal light is, for example, white light or green light. In narrow-band light observation, which is a type of special light observation, by irradiating blue light and green light alternately, the wavelength dependence of light absorption in body tissue can be utilized to image predetermined tissues such as blood vessels on the surface of mucous membranes with high contrast. Furthermore, in fluorescence observation, a type of special light observation, excitation light is irradiated onto a drug injected into body tissue to excite it, and a fluorescence image is obtained by receiving the fluorescence emitted by the body tissue or the labeling drug. This makes it easier for the operator to visualize body tissues and other areas that are difficult to see with normal light. For example, in fluorescence observation using infrared light, infrared light having an excitation wavelength band is irradiated onto a drug such as indocyanine green (ICG) injected into body tissue, and the structure of the body tissue and the affected area can be made easier to visualize by receiving the fluorescence of the drug. In addition, in fluorescence observation, a drug that is excited by special light in the blue wavelength band and emits fluorescence in the red wavelength band (e.g., 5-ALA) may be used. The type of irradiation light of the light source device 5043 is set by the control of the CCU 5039. The CCU 5039 may have a mode in which normal light observation and special light observation are performed alternately by controlling the light source device 5043 and the endoscope 5001. In this case, it is preferable to superimpose information based on the pixel signals obtained by special light observation onto the pixel signals obtained by normal light observation. Furthermore, the special light observation may be infrared light observation, which involves irradiating with infrared light to view areas deeper than the organ surface, or multispectral observation utilizing hyperspectral spectroscopy. In addition, photodynamic therapy may be combined.

[0136] <Recording Device> The recording device 5053 is a device that records pixel signals (e.g., images) acquired from the CCU 5039, and is, for example, a recorder. The recording device 5053 records the images acquired from the CCU 5039 onto an HDD, SSD, or optical disc. The recording device 5053 may be connected to a hospital network and made accessible from equipment outside the operating room. The recording device 5053 may also have an image down-conversion or up-conversion function.

[0137] <Display Device> The display device 5041 is a device capable of displaying images, such as a display monitor. The display device 5041 displays a display image based on the pixel signals acquired from the CCU 5039. The display device 5041 may also function as an input device that enables eye-tracking, voice recognition, and gesture-based instruction input by equipping it with a camera and microphone.

[0138] <Output Device> The output device 5055 is a device that outputs information acquired from the CCU 5039, and is, for example, a printer. The output device 5055 prints a print image on paper based on the pixel signals acquired from the CCU 5039.

[0139] <Support Device> The support device 5027 is a multi-joint arm comprising a base portion 5029 having an arm control device 5045, an arm portion 5031 extending from the base portion 5029, and a holding portion 5032 attached to the tip of the arm portion 5031. The arm control device 5045 is composed of a processor such as a CPU and controls the driving of the arm portion 5031 by operating according to a predetermined program. The support device 5027 controls the position and orientation of the endoscope 5001 held by the holding portion 5032, for example, by controlling parameters such as the length of each link 5035 constituting the arm portion 5031 and the rotation angle and torque of each joint 5033 using the arm control device 5045. This allows the endoscope 5001 to be changed to a desired position or orientation, the scope 5003 to be inserted into the patient 5071, and the observation area inside the body to be changed. The support device 5027 functions as an endoscope support arm that supports the endoscope 5001 during surgery. As a result, the support device 5027 can act as a substitute for the scopist, who is an assistant holding the endoscope 5001. The support device 5027 may also be a device that supports the microscope device 5301, which will be described later, and can also be called a medical support arm. The support device 5027 may be controlled autonomously by the arm control device 5045, or it may be controlled by the arm control device 5045 based on user input. For example, the control method may be a master-slave system in which the support device 5027, acting as a slave device (replica device) which is a patient cart, is controlled based on the movement of the master device (primary device), which is the operator console at the user's location. Furthermore, the support device 5027 may be controlled remotely from outside the operating room.

[0140] The above describes an example of an endoscopic system 5000 to which the technology relating to this disclosure may be applied. For example, the technology relating to this disclosure may be applied to a microscope system.

[0141] <Microscope System> Figure 17 shows an example of a schematic configuration of a microscope surgery system to which the technology described herein may be applied. In the following description, components similar to those in the endoscope system 5000 are denoted by the same reference numerals, and redundant explanations are omitted.

[0142] Figure 17 schematically shows a surgeon 5067 performing surgery on a patient 5071 on a patient bed 5069 using a microsurgical system 5300. For simplicity, Figure 17 omits the cart 5037 from the configuration of the microsurgical system 5300, and the microscope device 5301, which replaces the endoscope 5001, is shown in a simplified form. However, in this description, the microscope device 5301 may refer to the microscope unit 5303 located at the tip of the link 5035, or it may refer to the entire configuration including the microscope unit 5303 and the support device 5027.

[0143] As shown in Figure 17, during surgery, the image of the surgical site captured by the microscope device 5301 is displayed enlarged on a display device 5041 installed in the operating room using the microsurgery system 5300. The display device 5041 is positioned opposite the surgeon 5067, and the surgeon 5067 observes the surgical site through the image displayed on the display device 5041 and performs various procedures on the site, such as excising the affected area. Microsurgery systems are used, for example, in ophthalmic surgery and neurosurgery.

[0144] Examples of endoscopic systems 5000 and microsurgical systems 5300 to which the technology relating to this disclosure may be applied have been described above. However, the systems to which the technology relating to this disclosure may be applied are not limited to these examples. For example, the support device 5027 may support other observation devices or other surgical instruments at its tip in place of the endoscope 5001 or the microscope unit 5303. Examples of such other observation devices include forceps, clamps, insufflation tubes for pneumoperitoneum, or energy treatment instruments for tissue incision or blood vessel sealing by cauterization. By supporting these observation devices and surgical instruments with the support device, it becomes possible to fix their position more stably than when medical staff support them manually, and the burden on medical staff can be reduced. The technology relating to this disclosure may also be applied to a support device that supports components other than the microscope unit.

[0145] The technology relating to this disclosure can be suitably applied to a light source device, such as the light source device 5043, among the configurations described above. This increases the possibility of improving the accuracy of drug fluorescence observation. For example, clearer surgical site images can be obtained, making it possible to perform surgery more safely and reliably.

[0146] The effects described in this disclosure are merely illustrative and not limited to those disclosed. Other effects may also occur.

[0147] While embodiments of this disclosure have been described above, the technical scope of this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the gist of this disclosure. Furthermore, components from different embodiments and modifications may be combined as appropriate.

[0148] Furthermore, this technology can also take the following configurations: (1) A light source device for medical use, comprising: a light source that outputs light for obtaining white light for illumination and excitation light for drug excitation; and an optical system that guides the light from the light source to an external light guide, wherein the optical system includes at least one lens, and the at least one lens satisfies at least one of the following conditions: that the yttrium oxide content is less than 10% by weight and that the gadolinium oxide content is less than 1% by weight. (2) The light source device according to (1), wherein the at least one lens satisfies both of the following conditions: that the yttrium oxide content is less than 10% by weight and that the gadolinium oxide content is less than 1% by weight. (3) The light source device according to (1) or (2), wherein the material of the at least one lens includes glass. (4) The light source device according to any one of (1) to (3), wherein the at least one lens includes a downstream lens provided to face the external light guide, and the downstream lens satisfies at least one of the above conditions. (5) The light source device according to (4), wherein the distance between the rear lens and the external light guide is 7 mm or more and 23 mm or less. (6) The light source device according to any one of (1) to (5), wherein the white light includes blue light, green light and red light, the excitation light includes blue light, and the peak wavelength of the excitation light is 440 nm or more and 480 nm or less. (7) The light source device according to any one of (1) to (6), wherein the light source includes at least one of a narrowband light source and a broadband light source, the narrowband light source includes a semiconductor laser, and the broadband light source includes at least one of a lamp, an LED and a phosphor. (8) The light source device according to any one of (1) to (7), wherein the light source includes a blue light source, and the blue light source is a narrowband light source including a semiconductor laser. (9) The light source device according to any one of (1) to (8), wherein the at least one lens comprises a front lens provided to face the light source and a rear lens provided to face the external light guide, and both the front lens and the rear lens satisfy at least one of the above conditions.(10) The light source is a plurality of light sources, and the at least one lens includes a downstream lens provided to face the external light guide, a first upstream lens provided to face the first light source, and a second upstream lens provided to face the second light source, and the optical system includes an internal light guide provided between the first upstream lens and the downstream lens, and a multiplexing element that combines the light from the internal light guide and the light from the second upstream lens and guides them to the downstream lens, as described in any one of (1) to (9). (11) The light source device according to (10), wherein the internal light guide includes at least one of a rod and an optical fiber. (12) The light source device according to (10) or (11), wherein the size of the optical output surface of the internal light guide is the same as the size of the optical output surface of the second light source. (13) The light source device according to any one of (10) to (12), wherein the first light source is a plurality of first light sources, and the internal light guide integrates the light from the plurality of first light sources. (14) The light source device according to any one of (10) to (13), wherein the multiplexing element includes a dichroic mirror. (15) The light source device according to any one of (10) to (14), wherein the optical system includes a conversion element provided between the first preamplifier lens and the internal light guide such that the light from the first preamplifier lens is incident on the internal light guide at an angle. (16) The light source device according to (15), wherein the conversion element includes at least one of a diffuser plate, a fly eye, and a microlens array. (17) The light source device according to any one of (1) to (16), wherein the at least one lens includes at least one of a spherical lens and an aspherical lens. (18) The external light guide is connected to an endoscope or surgical microscope, and is a light source device according to any one of (1) to (17).

[0149] 1 Light source device 2 Light source 2-1 Light source (first light source) 2-2 Light source (second light source) 2-A Light source 2-B Light source 2-C Light source 3 Optical system 4 Lenses 4-F Front lens 4-F-1 Front lens 4-F-2 Front lens 4-L Rear lens 4-M Middle lens 4-M-1 Middle lens 4-M-2 Middle lens 5 Mirror 5-1 Mirror 5-2 Mirror 5-A Mirror 5-B Mirror 5-C Mirror 6 Diffuser plate 6-1 Diffuser plate 6-2 Diffuser plate 7 Internal light guide 8 External light guide 81 Endoscope 82 Imaging device 83 Filter 9 Screen D Distance Lo Light Ls Light Ls-1 Light Ls-2 Light Ls-A Light Ls-B Light Ls-C Light

Claims

1. A medical light source device comprising: a light source that outputs light for obtaining white light for illumination and excitation light for drug excitation; and an optical system that guides the light from the light source to an external light guide, wherein the optical system includes at least one lens, and the at least one lens satisfies at least one of the following conditions: that the yttrium oxide content is less than 10% by weight and that the gadolinium oxide content is less than 1% by weight.

2. The light source device according to claim 1, wherein at least one lens satisfies both conditions: the yttrium oxide content is less than 10% by weight and the gadolinium oxide content is less than 1% by weight.

3. The light source device according to claim 1, wherein the material of at least one lens includes glass.

4. The light source device according to claim 1, wherein the at least one lens includes a downstream lens provided opposite the external light guide, and the downstream lens satisfies at least one of the conditions.

5. The light source device according to claim 4, wherein the distance between the rear lens and the external light guide is 7 mm or more and 23 mm or less.

6. The light source device according to claim 1, wherein the white light includes blue light, green light, and red light, the excitation light includes blue light, and the peak wavelength of the excitation light is 440 nm or more and 480 nm or less.

7. The light source device according to claim 1, wherein the light source includes at least one of a narrowband light source and a broadband light source, the narrowband light source includes a semiconductor laser, and the broadband light source includes at least one of a lamp, an LED, and a phosphor.

8. The light source device according to claim 1, wherein the light source includes a blue light source, and the blue light source is a narrowband light source including a semiconductor laser.

9. The light source device according to claim 1, wherein the at least one lens comprises a front lens provided to face the light source and a rear lens provided to face the external light guide, and both the front lens and the rear lens satisfy at least one of the above conditions.

10. The light source is a plurality of light sources, and the at least one lens includes a rear lens provided to face the external light guide, a first front lens provided to face the first light source, and a second front lens provided to face the second light source, and the optical system includes an internal light guide provided between the first front lens and the rear lens, and a multiplexing element that combines the light from the internal light guide and the light from the second front lens and guides them to the rear lens, the light source device according to claim 1.

11. The light source device according to claim 10, wherein the internal light guide includes at least one of a rod and an optical fiber.

12. The light source device according to claim 10, wherein the size of the light output surface of the internal light guide is the same as the size of the light output surface of the second light source.

13. The light source device according to claim 10, wherein the first light source is a plurality of first light sources, and the internal light guide integrates the light from the plurality of first light sources.

14. The light source device according to claim 10, wherein the multiplexing element includes a dichroic mirror.

15. The light source device according to claim 10, wherein the optical system includes a conversion element provided between the first pre-lens and the internal light guide such that light from the first pre-lens is incident on the internal light guide at an angle.

16. The light source device according to claim 15, wherein the conversion element includes at least one of a diffuser plate, a fly eye, and a microlens array.

17. The light source device according to claim 1, wherein the at least one lens includes at least one of a spherical lens and an aspherical lens.

18. The light source device according to claim 1, wherein the external light guide is connected to an endoscope or surgical microscope.

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