TW202041188A - Medical microscope apparatus - Google Patents

Abstract

This medical microscope apparatus for displaying is provided with: a solid-state imaging device and a display device. The imaging unit is equipped with a solid-state imaging element in which a plurality of pixels, each having a photoelectric conversion element, are arranged in a matrix configuration on an image forming surface. When an image of a circular observation region having a diameter of 20 mm is captured by the solid-state imaging device and displayed on a display screen provided to the display device, an observation region image formed on the image forming surface of the solid-state imaging device has a circular shape having a diameter equal to the length of at least 4000 pixels arranged in juxtaposition. The observation region is shown, on the display screen of the display device, in a circular shape having a diameter represented by at least 4000 display pixels.

Description

Medical microscope device

The present invention relates to a medical microscope device.

In recent years, ultra-high-quality (8K) cameras have received medical applications due to digital imaging technology. In particular, it has begun to be applied to various areas in endoscopic surgery in which operations are performed while watching TV images (Non-Patent Document 1 to Non-Patent Document 3). The ultra-high image quality allows for very effective magnification on the screen, so it is expected to obtain an image comparable to that of a microscope (Non-Patent Document 4).

In addition, Patent Document 1 discloses a medical microscope device including a configuration in which an image of the surgical site is captured by an imaging element, and information about the captured image is sent to a display device to obtain a captured image of the surgical site. Displayed on a display device; this medical microscope device, as an example of a medical microscope device, includes a solid-state imaging device having a solid-state imaging element and a lens optical system and photographing observation objects, and a display device that displays image data taken by the solid-state imaging device .

On the other hand, the inventors of the present invention conducted a non-deterioration test with an optical microscope using an 8K high-quality microscope in the ophthalmology area using a pig eye model and confirmed that it is not inferior (Non-Patent Document 4). It is also known that 3D has a higher learning effect than 2D (Non-Patent Document 5). In recent years, optical microscopes are capable of super-magnification under both eyes, so they have been clinically established in the field of super microsurgery that can perform anastomosis of blood vessels or lymph vessels with a diameter of 0.5 millimeters (mm) or less. [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication WO2016/017532 Publication [Non-Patent Literature]

[Non-Patent Document 1] Yamashita H, Aoki H, Tanioka K, Mori T, Chiba T. Ultra-high definition (8K UHD) endoscope: our first clinical success. Springerplus. 2016 Aug 30; 5(1):1445. doi : 10.1186/s40064-016-3135-z. eCollection 2016. [Non-Patent Document 2] Aoki Y, Matsuura M, Chiba T, Yamashita H. Effect of an 8K ultra-high-definition television system in a case of laparoscopic gynecologic surgery. Wideochir Inne Tech Maloinwazyjne. 2017 Sep; 12(3): 315-319. doi: 10.5114/wiitm.2017.68830. Epub 2017 Jul 7. [Non-Patent Document 3] Ohigashi S, Taketa T, Shimada G, Kubota K, Sunagawa H, Kishida A. Fruitful first experience with an 8K ultra-high-definition endoscope for laparoscopic colorectal surgery. Asian J Endosc Surg. 2018 Dec 13. doi: 10.1111/ases. 12638. [Epub ahead of print] [Non-Patent Document 4] Yamashita H, Tanioka K, Miyake G, Ota I, Noda T, Miyake K, Chiba T. 8K ultra-high-definition microscopic camera for ophthalmic surgery. Clin Ophthalmol. 2018 Sep 19;12:1823- 1828. doi: 10.2147/OPTH. S171233. eCollection 2018. [Non-Patent Document 5] Chhaya N, Helmy O, Piri N, Palacio A, Schaal S. COMPARISON OF 2D AND 3D VIDEO DISPLAYS FOR TEACHING VITREORETINAL SURGERY. Retina. 2018 Aug; 38(8):1556-1561. doi: 10.1097 /IAE. 0000000000001743

[The problem to be solved by the invention]

As described above, with the use of the medical microscope device described in Patent Document 1, the surgeon can anastomize blood vessels or lymphatic vessels with a diameter of about hundreds of μm only by performing surgery by directly looking at a binocular microscope. Expectations of surgery continue to increase. However, the super-magnified image has the problem of poor binocular microscope: the depth of focus becomes shallow, or the input electronic image data is halved in order to obtain a 3D image in a screen. Therefore, the operation of anastomosing such thin tubes using the medical observation device of the prior art is no longer performed.

An object of the present invention is to provide a medical microscope device that displays an image that can be subjected to anastomosis processing even if the minor axis diameter (caliber) of the processing target is 500 μm or less, on a screen. [Means to Solve the Problem]

One aspect of the present invention provided to solve the above-mentioned problems is a medical microscope device, including a solid-state imaging device and a display device, the solid-state imaging device has an imaging unit and a lens optical unit, and the solid-state imaging device imaging includes observation An image of an object, the display device displays the image taken by the imaging unit, and the imaging unit includes a solid-state imaging device in which a plurality of pixels each having a photoelectric conversion element are arranged in a matrix on an imaging surface Element, when a circular observation area with a diameter of 20 millimeters (mm) is captured by the solid-state imaging device and displayed on the display screen included in the display device, the observation area formed on the imaging surface of the solid-state imaging device The image is a circle with a diameter of more than 4,000 pixels in the array, and the observation area is a circle whose diameter is represented by more than 4,000 display pixels on the display screen of the display device.

When performing the anastomosis process, because of the work of tightening the sutures, a circular shape with a diameter of 20 mm or an observation area with a size equal to or larger than the circular shape is required. The ability to display the observation area on one display screen is a necessary condition for performing anastomosis processing while observing only the display screen of the microscope device.

For example, when a lymphatic vessel with a diameter of about 500 μm is used as the treatment target, the medical suture thread used for the treatment of anastomosing the cut lymphatic vessel is appropriately 20 μm to 29 μm in diameter, that is, the thread diameter is approximately It is a 25 μm USP (United States Pharmacopoeia) No. 10-0 or a wire with a wire diameter below it. In order to perform the anastomosis process using a microscope device, it is necessary to be able to confirm the imaging pixel density (the pixel of the solid-state imaging element (in order to distinguish it from the "display pixel", also called "imaging Pixel")) and display pixel density (display pixel density).

The density of imaging pixels can be defined by a circular observation area with a diameter of 20 mm on the imaging surface of the solid-state imaging device, and how large a circular image is formed in relation to the imaging pixels. The circular image imaged on the imaging surface is located within the range of the solid-state imaging element in which a plurality of imaging pixels are arranged in a matrix, and the range is preferably larger. In one aspect of the present invention, the circular image on the imaging surface is a circle having a diameter of four thousand or more imaging pixels arrayed by the solid-state imaging element. If imaging in this way, it is possible to image the 10-0 suture with more than five pixels, which is approximately 25 μm of its diameter, even for the 12-0 suture with a thread diameter of 1 μm to 9 μm. , Can also shoot with multiple camera pixels. In this way, by setting the lens optical system such that the number of pixels in the short axis direction of the solid-state image sensor is four thousand or more, and the length of the observation object photographed by one image pixel is 5 μm or less, it is possible to The observation area (a circle with a diameter of 20 mm) required for the anastomosis process is captured by a solid-state image sensor, and the 12-0 suture line is captured by multiple image elements.

In the display screen, it is necessary to display without reducing the pixel density of the captured image. In contrast, in the medical microscope device of one aspect of the present invention, an observation area having a circular shape with a diameter of 20 mm is displayed on the display screen of the display device as a circle whose diameter is represented by more than four thousand display pixels Display the image. Therefore, the length of the observation object displayed by one display pixel on the display screen is 5 μm or less. By forming the display image in this way, the width of the stitching line No. 12-0 captured by a plurality of imaging pixels in the solid-state imaging device can be displayed with the number of display pixels greater than the number of imaging pixels on the display screen. The number of display pixels in the short axis direction of the display screen of the display device is preferably more than the number of pixels in the short axis direction of the solid-state image sensor.

Here, when performing the matching process, there is a situation where the digital zoom and the image padding process are combined, and the display screen is enlarged and displayed with a pixel density higher than the imaging pixel density. In this case, if the length of the observation object captured by one imaging pixel is set to 5 μm or less as described above, even a fine suture thread (No. 12-0) with a diameter of about 10 μm can be used. The width direction of the shooting line of each camera pixel. This situation means that as a whole, only the imaging pixels that capture the line exist in the width direction of the line. In the case of such a camera pixel, even if the display pixel corresponding to the camera pixel is digitally zoomed and the padding process is performed to generate multiple display pixels with different color information, among the display pixels It is not easy to lose the information on the line. Therefore, by digitally zooming the displayed image, it is not easy to cause the defects of line interruption display.

From the viewpoint of ensuring the operator's workability, the distance (working distance) between the observation target and the solid-state imaging device is preferably 200 mm or more.

The imaging optical axis of the solid-state imaging device is preferably inclined at a specific inclination angle (first inclination angle θ) with respect to the vertical direction. In this case, the vertical movement distance of the observation target (suture needle or suture thread) in the anastomosis process becomes cosθ times in the imaging optical axis direction. Therefore, the effective depth of field can be enlarged to 1/cosθ times, the observation object is in the field of view during the anastomosis process, and the possibility of being unrecognizable can be reduced. From the viewpoint of making this effect particularly apparent, the inclination angle (first inclination angle θ) may be preferably 15 degrees or more. On the other hand, if the inclination angle (the first inclination angle θ) becomes too large, the movement of the observation object (such as the suture needle) in the displayed image will hardly reflect the actual movement, or the objects around the observation object interfere and make it difficult to observe The object is appropriately displayed on the display screen of the display device. Therefore, in some cases, the inclination angle (the first inclination angle θ) is preferably set to 60 degrees or less.

The medical microscope device of one aspect of the present invention further includes an irradiating device for irradiating the observation object. The inclination angle (the second inclination angle ψ) between the irradiation optical axis of the irradiating device and the imaging optical axis corresponds to the vertical direction between the observation object and its surroundings. The distance is set to provide an appropriate image on the displayed image and give a three-dimensional effect. The tilt angle is set to correspond to the width of the shadow of the observation object caused by tilting the irradiation optical axis and the imaging optical axis, preferably less than the maximum length of the observation width of the observation object, and more than 1/2 of the maximum length range. In addition, when the distance in the vertical direction between the observation object and its surroundings is zero, the inclination angle is 60 degrees or more and 80 degrees or less, preferably as the distance between the observation object and its surroundings in the vertical direction increases, the inclination The angle setting becomes smaller.

Furthermore, in the anastomosis process, the suture line moves three-dimensionally in the field of view, specifically, it can be displaced at least ±10 mm in the direction of the imaging optical axis. Therefore, in the entire observation area including a spherical space with a diameter of 20 mm, it is preferable to be able to visually recognize the No. 12-0 suture. [Effects of the invention]

According to the present invention, there is provided a medical microscope device that displays an image capable of performing anastomosis processing even if the short axis diameter of the processing target is 500 μm or less on a screen.

FIG. 1 is a schematic diagram for explaining the configuration of a medical microscope device according to an embodiment of the present invention. FIG. 2( a) is a schematic diagram for explaining an image of an observation area formed on the imaging surface of the solid-state imaging element of the medical microscope according to the embodiment of the present invention. FIG. 2(b) is a schematic diagram for explaining a display image of the display device of the medical microscope according to the embodiment of the present invention.

As shown in FIG. 1, a medical microscope device 100 according to an embodiment of the present invention includes a solid-state imaging device 10, a processing device 40, and a display device 50. The solid-state imaging device 10 includes a lens optical section 30 arranged along an imaging optical axis OA, and an imaging section 20 having a solid-state imaging element 21 located on an imaging surface FS of the lens optical section 30. In the present embodiment, the observation area OR is a part of the processing area SA of the object A, and the imaging optical axis OA is arranged obliquely at a specific angle (first inclination angle θ) with respect to the vertical direction VL. The details of this configuration will be described below.

In this embodiment, the observation area OR is a circle with a diameter Dr, and a specific example of the diameter Dr is 20 mm. The observation area OR captured by the lens optical system LS of the lens optical section 30 is imaged on the imaging surface FS of the solid-state imaging element 21 to form an imaged image IM. The imaging image IM is a circle with a diameter Di. Furthermore, the observation area OR is a part of the area (observable area OR0) that can be observed by the lens optical system LS, and the solid is arranged so that the observable area OR0 and the imaging image IM0 formed by the imaging surface FS are inscribed The imaging element 21. Therefore, on the display screen 51, an image outside the range of the observation area OR is also displayed.

As shown in (a) of FIG. 2, the solid-state imaging element 21 has a plurality of pixels (imaging pixels) Px each having a photoelectric conversion element, and the imaging pixels Px are arranged in a matrix on the imaging surface FS. The size (pixel size) Ds of the imaging pixel Px of the solid-state imaging element 21 of this embodiment is a square of 3.2 μm in both the X direction and the Y direction. In the solid-state imaging element 21 of this embodiment, the imaging pixels Px are arranged in the X direction, 7,680 pixels, and in the Y direction, 4,320 pixels. Therefore, as the size of the solid-state imaging element 21, the length in the X direction is 24.6 mm, and the length in the Y direction is 13.8 mm.

In the solid-state imaging device 10 of the present embodiment, the diameter Di of the circular imaging image IM produced on the imaging surface FS including the circular observation area OR with a diameter of 20 mm is 12.8 mm. Since the size of the imaging pixel Px is 3.2 μm, the number Ni of arrays of imaging pixels Px corresponding to the diameter Di of the circular imaging image IM with the diameter Di is four thousand.

In this way, since the length of 20 mm of the observation area OR is captured by four thousand imaging pixels Px, the observation length of each imaging pixel Px is 5 μm. When the observation object located in the observation area OR is the No. 10-0 suture thread AY, the diameter of the thread is 20 μm to 29 μm, but since the observation length of each imaging pixel Px is 5 μm as described above, 10 -No. 0 suture thread AY is captured by at least four or more camera pixels Px arranged in a row. Even for the 12-0 suture thread, 5 μm, which is the arithmetic mean of the thread diameter, is the same as the observation length of each imaging pixel Px, so the 12-0 thread can be stably captured. That is, when shooting the 12-0 line, only the imaging pixels Px of the imaging line always exist in the width direction of the line. As a result, only the imaging pixels Px of the imaging line are not in the long axis direction of the line. Will be interrupted and arranged.

An electrical signal including information of an image captured by the solid-state imaging device 10 is input to the processing device 40 via the cable 41. The processing device 40 performs signal processing to generate an image display signal. The image display signal output from the processing device 40 is input to the display device 50 via the cable 42 and displayed on the display screen 51 as a display image. The display screen 51 is arranged with 7,680 display pixels in the X direction and 4,320 display pixels in the Y direction, resulting in a total of more than 33 million display pixels. The display image is formed. Therefore, all the circular images DI representing the circular observation area OR with a diameter Dr of 20 mm are displayed on the display screen 51.

On the display screen 51 of the display device 50, as an example, an image showing a state in which a lymphatic vessel Ld with a diameter of 500 μm or less is anastomosed with a suture thread AY is displayed. The two ends of the suture thread AY are held by the forceps T1 and T2, and the anastomosis is completed by pulling the forceps T1 and T2.

In the anastomosis process, as shown in FIG. 3, the operation of clamping the suture thread AY of diameter Dy with the forceps T1 is performed. Therefore, if the suture thread AY cannot be displayed on the display screen 51, the anastomosis process cannot be performed. In contrast, on the display screen 51 of the display device 50 of the medical microscope device 100 of the present embodiment, the observation area OR is displayed as a circular image DI whose diameter is represented by the number of display pixels Nd of four thousand or more. By displaying in this manner, the image captured by the solid-state imaging device 21 is displayed on the display screen 51 without reducing the resolution, and the sewing thread No. 10-0 or No. 12-0 can be visually recognized on the display screen 51.

4 is a diagram showing a specific example of an image observed using the medical microscope device according to an embodiment of the present invention. The solid-state imaging element 21 of the solid-state imaging device 10 of the medical microscope device 100 has 7,680 horizontal and 4,320 vertical pixels, and the pixel size is 3.2 μm. The image captured by the solid-state imaging device 10 is displayed on a display device 50 having a display screen 51 with 7,680 horizontal and 4,320 vertical display pixels. Therefore, the observation length of each display pixel in the display screen 51 is the same as the observation length of each imaging pixel, which is 5 μm. In the display screen 51, a circular observation area OR with a diameter of 20 mm can be displayed. The area is 38.4 mm wide and 21.6 mm long.

Fig. 4(a) is a diagram obtained by digitally zooming a part of the display image (observation length per display pixel: 5 μm) displayed on the display screen 51 by four times, and then performing the padding process described below Like. FIG. 4(b) is an enlarged image of a part surrounded by four corners indicated by a two-dot chain line in FIG. 4(a). This part is equivalent to the size of 8 mm in width and 11 mm in length in the observation area OR, and the black line extending in the longitudinal direction in (b) of FIG. 4 is the No. 10-0 suture AY. If a part of the display image is digitally zoomed to four times, the original image of one display pixel is displayed as sixteen display pixels due to zooming, and therefore the image displayed on the display screen 51 becomes thicker. In the padding process performed to improve the degradation of the image quality, based on the color information of each display pixel before zooming and the color information of multiple display pixels around the display pixel, the sixteen displays after zooming Set color information for each pixel. Therefore, the color information of the sixteen display pixels formed by the padding process includes not only the color information of the one display pixel before the enlargement as the processing target, but also the color information of the surrounding image. The reception of the color information of the surrounding image causes the display of the stitching line AY described below to be interrupted.

When the length of the observation object displayed by one display pixel before zooming is longer than the diameter of the stitch line AY, when the stitch line AY is displayed, there is no display pixel that only displays the stitch line AY. Therefore, the display pixels displaying the stitching line AY not only include the stitching line AY, but also the color information of the surrounding image. As a result, the color information of the display pixel showing the stitching line AY becomes the color information in which the color information of the original stitching line AY is diluted by the color information of the surrounding image.

If the digital zoom and padding processing are performed in this state, the color information of the display pixels around the display pixel before zooming is used in the padding processing to generate the individual color information of sixteen display pixels. The ratio of the color information of the stitching line AY contained in the color information of the sixteen display images obtained by the padding process is lower than the ratio of the color information of the stitching line AY contained in the display pixels before zooming. If the decrease in the ratio becomes obvious, the observer (surgeon) cannot recognize that the sixteen displayed images show sutures AY, and the sutures AY are not continuous in the long axis direction in the display image. "Interrupt" displayed. The interruption of the display of the suture line AY during the digital zoom is an essential problem for the operator performing the anastomosis treatment: it should be a magnified display that requires fine work, but the suture line AY is partially not displayed, so the anastomosis cannot be continued. deal with.

In contrast, like the medical microscope device 100 of the present embodiment, when the length of the observation object displayed by one display pixel is less than the diameter of the suture line AY, only the display pixels of the suture line AY are displayed for the suture. The line AY is arranged continuously in the long axis direction. Therefore, even in the case of digital zoom and padding processing, the content ratio of the color information of the surrounding image of the stitching line AY among the sixteen display pixels generated based on displaying only the display pixels of the stitching line AY Not easy to get high. Therefore, in the medical microscope device 100 of this embodiment, the display of the suture line AY at the time of digital zooming is less likely to be interrupted, and the anastomosis process can be performed stably.

In Figure 4(b), in order to confirm how many display pixels the width of the stitch line AY is displayed, the part enclosed by the four corners indicated by the two-dot chain line in Figure 4(b) is enlarged and displayed in Figure 5, and further, It is further enlarged in the part enclosed by the four corners represented by the two-dot chain line in FIG. 5. As a result, as shown in FIG. 6, the display image is displayed as an aggregate of a plurality of display pixels of individually set colors. From this image, the number of display pixels in the width direction of the display seam line AY is calculated. As shown in Fig. 6, since the width of the suture line AY shown by the double arrow is represented as a rectangular diagonal line with 13 display pixels in the vertical direction and 16 display pixels in the horizontal direction, it is confirmed that it is approximately Twenty display pixels are displayed. The number of pixels is equal to the theoretical value. Even if digital zooming and padding are performed, it is confirmed that the No. 10-0 stitching line AY is properly displayed. That is, the diameter of the No. 10-0 suture AY is 20 μm to 29 μm and the arithmetic average is about 25 μm. In the equal magnification display image shown in Figure 4(a), due to one display pixel display The length of the observation object is 5 μm, so the width of the No. 10-0 suture line AY in the display image of Fig. 4(a) is calculated to be represented by approximately five display pixels, in Fig. 6 enlarged to four times In the display image of, it is calculated to be represented by approximately twenty display pixels.

In this manner, according to the medical microscope device 100 of the present embodiment, not only can the observation area OR having a circular shape with a diameter of 20 mm be displayed on the display screen 51, but also the suture thread AY as thin as No. 10-0 can be stably displayed. Specifically, even if the digital zoom is four times and the filling process is performed, it is not easy to cause the display interruption of the stitching line in the zoomed image.

Fig. 7 is a schematic diagram for explaining another configuration of the medical microscope device according to an embodiment of the present invention. In the medical microscope device 100 of this embodiment, the diameter Dr of the circular observation area OR is 25 mm. In addition, the diameter Di of the imaging image IM formed on the imaging surface FS also becomes 25 mm. That is, in the present embodiment, the lens optical system LS of the lens optical unit 30 is an equal magnification imaging system. Therefore, in this embodiment, the number Ni of arrays of imaging pixels Px corresponding to the diameter of the circular imaging image IM with the diameter Di is 7,680, and the observation length of each imaging pixel Px is 3.2 μm . Therefore, when the observation area OR is a circular shape with a diameter of 20 mm, the image of the observation area OR formed on the imaging surface FS of the solid-state imaging device 10 has a diameter with a length of 6,250 imaging pixels. The observation area OR is displayed on the display screen 51 of the display device 50 as a circle whose diameter is represented by 6,250 display pixels. Since the resolution of this configuration is higher than that of the configuration shown in FIG. 1, it is of course possible to stably image and display the No. 10-0 suture line, and it is also possible to image and display the No. 12-0 suture line particularly stably.

On the display screen 51 of the display device 50, a part of the circular image DI corresponding to the circular observation area OR with a diameter Dr of 25 mm is displayed. Specifically, since the number of display pixels in the Y direction, which is the short axis direction of the display screen 51, is 4,320, an area of 13.8 mm is displayed on the display screen 51 as the observation length. Therefore, in this embodiment, 68% of the circular image DI is displayed on the display screen 51. The display area is the area of the circular image DI when the observation area OR is a circle with a diameter of Dr20 mm (314 mm ² ) is equal to or more (1.05 times). Therefore, the anastomosis process can be performed stably. Rather, since the observation length of each display pixel is 3.2 μm, a sharper image than the image shown in FIG. 1 is displayed.

FIG. 8 is an image showing an observation area of 30.72 mm in width and 17.28 mm in length using the medical microscope device 100. In FIG. 8, since the ruler is displayed on the display screen 51, the length of 5 mm can be accurately confirmed. If calculated based on the displayed image, the observation length of each imaging pixel is about 4 μm. The upper part of the ruler shows the lymphatic vessel Ld. The diameter of the lymphatic vessel Ld is represented by the number of display pixels, which is about 180 μm. Furthermore, in FIG. 8, the circular image DI when the observation area OR is a circle with a diameter of 20 mm is represented by a double dashed line. Since the observation length of each imaging pixel is about 4 μm, the image of a circular observation area OR with a diameter of 20 mm formed on the imaging surface FS of the solid-state imaging device 10 is a diameter having a length of five thousand imaging pixels arranged The observation area OR becomes a circle whose diameter is represented by five thousand display pixels in the display screen 51 of the display device 50.

An image showing the result of suturing the lymphatic vessel Ld with No. 12-0 suture AY is shown in FIG. 9. (A) of FIG. 9 is an image obtained by digitally zooming a display image of an observation area of 1.6 mm in width and 1.8 mm in length including the lymphatic vessel Ld in FIG. 8 to four times and performing padding processing. Therefore, in the image in (a) of FIG. 9, the observation length of each display pixel is 1 μm. From Fig. 9(a), it can be confirmed that the lymphatic vessel Ld is anastomosed by the 12-0 suture line AY. This image is partially enlarged, and as in the case of FIG. 6, the 12-0 stitching line AY is displayed as an aggregate of a plurality of pixels with individually set colors (FIG. 9( b )).

As shown in Figure 9(b), since the width of the No. 12-0 stitching thread AY in the width direction is a rectangle made from nine display pixels in the vertical direction and five display pixels in the horizontal direction It is indicated by diagonal lines, so the number of display pixels is about ten. Based on the number of display pixels, the width of the observed suture line AY of No. 12-0 is about 10 μm. Since the image in FIG. 9 is obtained by enlarging the image in FIG. 8 to four times, in the display screen 51 shown in FIG. 8, the width direction of No. 12-0 stitching line AY is displayed from two to three Pixel display. Since the color of the suture thread AY is black, which is very different from the color of the tissue, the surgeon can fully recognize it even with a width of approximately 2.5 pixels. Therefore, even when the No. 12-0 suture thread AY is used, only the image displayed on the display screen 51 can be observed while performing the anastomosis process of the lymphatic vessel Ld.

10 is a schematic diagram for explaining the relationship between the vertical direction and the imaging optical axis in the medical microscope according to the embodiment of the present invention.

As shown in FIG. 1 or FIG. 7, in the medical microscope device 100 according to an embodiment of the present invention, the solid-state imaging device 10 has its optical axis (imaging optical axis OA) at a specific angle (first Tilt angle) θ tilted configuration. Therefore, if the member T such as tweezers is moved in the vertical direction by a specific length L1, the movement length L2 on the display screen 51 becomes L1×cosθ. In this way, since the moving length in the vertical direction VL is cosθ times, the depth of field effectively becomes a depth of 1/cosθ times.

From the viewpoint of making this effect (the effective enlargement of the depth of field) particularly apparent, the first tilt angle θ is preferably 15 degrees or more. On the other hand, if the first inclination angle θ becomes too large, the movement of the observation object (such as the suture needle) in the displayed image will hardly reflect the actual movement, or the objects around the observation object interfere and it is difficult to properly display the observation object. The display screen 51 of the display device 50. Therefore, in some cases, the first inclination angle θ is preferably set to 60 degrees or less. Considering the balance between the effective enlargement of the depth of field and the proper display of the display image, the first tilt angle θ is preferably set to 20 degrees or more and 40 degrees or less, and more preferably 30 degrees ± 5 degrees.

In addition, the angle formed by the optical axis (irradiation optical axis LA) of the irradiation light from the irradiation device 60 and the imaging optical axis OA (the second inclination angle ψ) is preferably set according to the vertical distance between the observation object and its surroundings . Generally, in a medical microscope device, it is performed to make the imaging optical axis OA coincide with the irradiation optical axis LA so that no shadow is generated in the captured image. Especially when the imaging pixel density is low, it is difficult to visually determine that the brightness reduction of this part is caused by the overlap of the shadows of other members such as the tweezers T1 and the tweezers T2. Or it is derived from a local shape change of the anastomosis object itself. Therefore, it is necessary to make the observation area OR in a shadowless state as much as possible to reduce the factors that impart brightness changes.

However, from the viewpoint of ensuring the three-dimensional effect of the observation target object, the observation area OR is clearly inferior in displaying an image in a shadowless state. When humans observe an object, not only the size of the observation object or the overlap with other objects, but also the shadow generated by the observation object or the arrangement of the shadow overlapping the observation object, grasp the three-dimensional sense of the observation object. Therefore, if the observation target is displayed in a shadowless state, it is difficult for the surgeon to grasp the three-dimensional effect. Specifically, when the observation object is the lymphatic vessel Ld, since the shape is tubular, the central portion is convex compared to the periphery, and as a result, it is difficult to grasp how much the central portion protrudes. This means that it is difficult to grasp the position of the needle during the anastomosis process, which becomes a negative factor for proper anastomosis process. In addition, if the displayed image is in a shadowless state, the sensitivity to the movement of the tweezers T1 and the tweezers T2 in the direction of the imaging optical axis OA is reduced, which causes excessive movements of the surgeon.

In the medical microscope device 100 of the present embodiment, as described above, even if the suture line AY is 12-0, it has a high resolution that can be appropriately displayed on the display screen 51. Therefore, even if the object located in the observation area OR has a part with reduced brightness, it can be visually recognized whether the part is derived from a change in the surface properties of the object or from a shadow. Therefore, in the medical microscope device 100, the imaging optical axis OA and the irradiation optical axis LA are actively shifted to produce a shadow in the observation area OR, and it is easy to grasp the three-dimensional effect of the observation object.

When the angle formed by the imaging optical axis OA and the illumination optical axis LA is set to the second inclination angle ψ, the second inclination angle ψ is preferably such that the width of the shadow of the observation object is less than the maximum length of the observation width of the observation object , And the angle is more than 1/2 of the maximum length. If the second inclination angle ψ is too large, the irradiation light from the irradiation device 60 cannot irradiate the entire observation area OR. As a result, it is not so much that the brightness change in the entire observation area OR becomes larger, and it is more difficult to grasp the three-dimensional effect. Furthermore, when the irradiation device 60 has a plurality of light sources, the irradiation optical axis LA is set based on the illuminance distribution composed of the entire light source.

From the viewpoint of appropriately ensuring the operator's operability, the working distance WD, which is the distance from the solid-state imaging device 10 to the object A, is preferably 200 mm or more. If the working distance WD becomes shorter, the distance between the light source of the irradiation device 60 and the object A tends to also become shorter. Therefore, the heat from the light source easily reaches the object A. From the viewpoint of suppressing the influence of the heat, it is preferable that the working distance WD is also long.

(Example 1) 11 is a graph showing the relationship between the observation angle θ and the actual depth of field d'in Example 1, and FIG. 12 is a graph showing the relationship between the scale pitch of the scale used in the measurement of the actual depth of field d'in Example 1 and the actual depth of field d' 13 is a graph showing the relationship between the observation angle θ and the actual field of view w'in Example 1. FIG. 14 is a diagram conceptually showing the relationship between the depth of field d, the actual depth of field d', and the actual field of view w'when the observation angle θ is set. In each figure, the F value is set to 8, 11, and 16 for each of lens I, lens II, and lens III.

As shown in FIG. 14, the observation angle θ is the inclination angle (first inclination angle) of the imaging optical axis OA of the solid-state imaging device 10 with respect to the vertical direction VL. The object A to be observed is arranged at the origin O which is the intersection of the vertical direction VL and the horizontal direction HL. The actual depth of field d′ is a range in which the depth of field d in the solid-state imaging device 10 is angle-converted along the vertical direction VL, and the actual field of view w′ is a range where the depth of field d is angle-converted along the horizontal direction HL.

The irradiation device 60 is arranged so that the irradiation light travels in the vertical direction VL and irradiates the object A. Therefore, the angle formed by the irradiation optical axis LA of the irradiation device 60 and the imaging optical axis OA of the solid-state imaging device 10 (the second inclination angle ψ) is set to be the same as the observation angle θ.

As described above, the actual depth of field d′ and the actual field of view w′ can be calculated based on the depth of field d in the solid-state imaging device 10, but they are measured as follows in the embodiment.

First, as the lens of the solid-state imaging device 10, the following configuration 1 to configuration 3 of a combination of a lens and a converter are used. The lens and the converter are arranged such that the optical axis of each of them overlaps with each other as the imaging optical axis OA of the solid-state imaging device 10. ＜Configuration 1＞ (A) Lens I Open F value 2.8, minimum F value 32, focal distance 60 mm, 7 groups 8 elements, angle of view 39°40' (B) Teleconverter TA 2 times magnification, 5 elements in 4 groups, 4 times exposure (2 aperture levels)

＜Configuration 2＞ (A) Lens II Open F value 2.8, minimum F value 32, 9 elements in 8 groups, focal distance 100 mm, viewing angle 24°30' (B) Teleconverter TB 1.4 times magnification, 3 elements in 2 groups, 2 times exposure (1 aperture series)

＜Configuration 3＞ (A) Lens III Model: Milvus 2/100M ZF.2 (manufactured by Carl Zeiss Co., Ltd.) Open F value 2.0, minimum F value 22, 9 elements in 8 groups, focal distance 100 mm, viewing angle 25° (B) Teleconverter TB 1.4 times magnification, 3 elements in 2 groups, 2 times exposure (1 aperture series)

The lens and the converter are arranged so as to form an observation angle θ with respect to the vertical direction VL, the scale arranged so as to extend in the horizontal direction HL is captured by 8K, and the actual depth of field d′ is calculated based on the captured image. In the photographed image, the grayscale value in each pixel generates an amplitude. This amplitude differs greatly between the range where the image is clear and the range where the image is not clear. Therefore, in order to discriminate these two ranges, if a threshold value is set for the magnitude of the amplitude, the range in which the amplitude exceeds the threshold value can be regarded as the actual depth of field d′.

Furthermore, as shown in FIG. 14, the following relational expressions (1), (2), and (3) are established between the observation angle θ, the actual depth of field d', and the actual field of view w'. The actual depth of field d'that is actually calculated calculates the actual field of view w'. 11 and 13 are graphs obtained based on the actual depth of field d′ actually calculated. w'=d/sinθ (1) d'cosθ=d (2) w'=d'cosθ/sinθ (3)

Also, as a scale, three types of scale pitches of 0.067 mm, 0.1 mm, and 0.2 mm are used. FIG. 12 shows the change in the actual depth of field d'caused by the difference in the scale pitch.

As shown in FIG. 11, when the observation angle θ is set to 30 degrees, 45 degrees, and 60 degrees, the actual depth of field d'can be calculated with respect to the observation angle θ in any of the aforementioned configurations 1 to 3. Moreover, based on these actual depths of field d', as shown in FIG. 13, the actual field of view w'can also be calculated.

As shown in FIG. 11, it can be seen that the actual depth of field d′ in Composition 1 to Composition 3 increases as the observation angle θ increases. The larger the F value of the lens, the greater the actual depth of field d′. In addition, it can also be seen that the actual depth of field d′ of the configuration 1 (the lens I) with a small focal length is larger than that of the configurations 2 and 3. Therefore, the observation angle θ, the focal length of the lens, and the F value of the lens can be changed according to the shape of the object A, observation conditions, and the like, and the desired actual depth of field d'can be set.

As shown in Fig. 12, it can be seen that even with the same lens, the larger the scale pitch of the scale, the larger the actual depth of field d'. Therefore, since the actual depth of field d′ may vary depending on the shape of the object A, etc., based on the results of FIG. 11, the optimal observation angle θ, lens type, F value, etc. are selected.

As shown in FIG. 13, the actual field of view w'changes with the increase of the observation angle θ in composition 1 to composition 3. Especially in the case of an F value of 11, it gradually becomes smaller. In addition, it can be seen that the larger the F value of the lens, the larger the actual field of view w'. In addition, it can also be seen that the actual field of view w′ of the configuration 1 (the lens I) with a small focal length is larger than that of the configuration 2 and the configuration 3. Therefore, the observation angle θ, the focal length of the lens, and the F value of the lens can be changed according to the shape of the object A, observation conditions, etc., to set the desired actual field of view w'.

A better observation angle θ based on the shape of the object A, observation conditions, etc. can be set based on the change in the actual depth of field d'shown in FIG. 11 and the change in the actual field of view w'shown in FIG.

(Example 2) FIG. 15(a) conceptually shows the inclination angle (first inclination angle θ (observation angle)) of the imaging optical axis OA of the solid-state imaging device 10 with respect to the vertical direction VL, and the irradiation optical axis LA of the irradiation device with respect to the imaging light A diagram showing the relationship between the inclination angle of the axis OA (the second inclination angle ψ), the observation target SB, and the width W10 of the shadow SD. FIG. 15(b) is a conceptual diagram of the observation target SB, the surrounding rear wall SC, A part of the image observed from the solid-state imaging device 10 with shade SD. As shown in FIG. 15(a), when the observation target SB is provided with light along the irradiation direction LD parallel to the irradiation optical axis LA, and observed along the imaging direction OD parallel to the imaging optical axis OA, it is from the vertical direction VL Observation, as shown in FIG. 15(b), a shadow SD with a width W10 is generated on the rear wall SC located on the rear side around the observation target SB. At this time, the observation target SB is observed with a width W20. Hereinafter, this width W20 is also referred to as an observation width W20.

16 to 18 show the width W10 of the shadow SD when irradiating the observation object SB under the conditions shown in FIG. 15 for each first tilt angle θ with respect to the angle of the irradiation optical axis LA with respect to the imaging optical axis OA (the first The graph of the change (vertical axis) in terms of two tilt angle ψ) (horizontal axis). 16 shows a case where the distance L10 in the vertical direction VL between the lymphatic vessel as the observation target SB and the surrounding posterior wall SC is 1.0 mm, and FIG. 17 shows a case where the distance L10 between the observation target SB and the posterior wall SC is 0.5 mm. FIG. 18 shows a case where the distance L10 between the observation target SB and the rear wall SC is 0 mm. In this case, the lower end SB1 of the observation target SB in the vertical direction is in contact with the rear wall SC.

The simulation conditions shown in Figs. 16 to 18 are as follows. (1) The diameter of the lymphatic vessel of SB as the observation object: 0.5 mm (2) The distance between the observation object SB (lymphatic vessel) and the posterior wall SC L10 (mm): 1.0 (Figure 16), 0.5 (Figure 17), 0 (Figure 18) (3) The first tilt angle θ (degrees (deg)): 30, 45, 60 (4) The emitted light from the irradiation device is parallel light, and the irradiation direction LD is parallel to the irradiation optical axis LA. (5) The angle of the irradiation optical axis LA relative to the imaging optical axis OA (the second inclination angle ψ): 0 to 90 degrees (deg) (horizontal axis in FIGS. 16 to 18)

The inventors discovered that the three-dimensional effect of the observation target SB is outstanding by irradiating the optical axis LA obliquely with respect to the imaging optical axis OA, and generating a shadow SD. Furthermore, in the image obtained by the solid-state imaging device 10, it can be seen that in order to obtain an appropriate stereoscopic effect, the width W10 of the shadow SD is preferably equal to or less than the maximum length of the observation width W20 of the observation target SB, and is the maximum length More than 1/2. The reason is that if the width W10 of the shadow SD is less than 1/2 of the maximum length, it is difficult to see, and if the width W10 is greater than the maximum length, on the contrary, the image deviates from the actual observation target SB and it is difficult to obtain a three-dimensional effect.

In the example shown in FIGS. 16 to 18, since the diameter of the lymphatic vessel of the observation target SB, that is, the maximum length of the observation width W20 of the observation target SB is 0.5 mm, the width W10 of the shadow SD (FIGS. 16-18 If the vertical axis of) is 0.25 mm or more and 0.5 mm or less, the better three-dimensional effect as described above can be obtained.

More specifically, as shown in FIG. 16, when the distance L10 between the observation target SB (lymphatic vessel) and the posterior wall SC is 1.0 mm (in the case of twice the diameter of the lymphatic vessel), the first tilt angle θ When it is 30 degrees and 45 degrees, it is preferable that the second inclination angle ψ (horizontal axis) is approximately 10-25 degrees. When the first inclination angle θ is 60 degrees, it is preferable that the second inclination angle ψ is approximately The range of 8 degrees to 22 degrees.

As shown in Figure 17, when the distance L10 is 0.5 mm (equal to the diameter of the lymphatic vessel), when the first inclination angle θ is 30 degrees, it is preferable that the second inclination angle ψ (horizontal axis) is approximately In the range of 20 to 42 degrees, when the first inclination angle θ is 45 degrees, the second inclination angle ψ is preferably about 20 degrees to 50 degrees, and when the first inclination angle θ is 60 degrees, it is preferably the second The inclination angle ψ is approximately in the range of 20 degrees to 55 degrees.

As shown in FIG. 18, when the distance L10 is 0 mm (when the lymphatic vessels are in contact with the posterior wall SC), when the first inclination angle θ is 30 degrees, the second inclination angle ψ (horizontal axis) is preferable The range is about 60 to 80 degrees. When the first inclination angle θ is 45 degrees, the second inclination angle ψ is preferably about 80 to 90 degrees. On the other hand, when the first inclination angle θ is 60 degrees, it is difficult to obtain an optimal shadow within the range of the second inclination angle ψ of 0 to 90 degrees.

As described above, the inclination angle (the second inclination angle ψ) between the illumination optical axis LA and the imaging optical axis OA can correspond to the distance in the vertical direction between the observation object SB and the surrounding rear wall SC. The preferred range. Furthermore, if the second tilt angle ψ is set so that the width W10 of the shadow SD of the observation target SB caused by tilting the irradiation optical axis LA and the imaging optical axis OA is equal to or less than the maximum length of the observation width W20 of the observation target SB and is the maximum length In the range corresponding to 1/2 or more, it is easy to see, and an image with a better three-dimensional effect can be obtained. Moreover, when the distance D10 in the vertical direction VL between the observation target SB and the surrounding rear wall SC is zero, the second inclination angle ψ is about 60 degrees to 80 degrees when the first inclination angle θ is 30 degrees. As the distance in the vertical direction VL between the observation target SB and the surrounding rear wall SC increases, it is preferable that the second tilt angle ψ is set to decrease.

100: Microscope device for medical use 10: Solid state camera 20: Camera Department 21: Solid-state imaging element 30: Lens optics 40: processing device 41: Cable 42: Cable 50: display device 51: display screen 60: Irradiation device A: Object AY: suture d: depth of field d': actual depth of field DI: circular image Dr: The diameter of the observation area OR Di: The diameter of the imaging image IM Ds: the size of the camera pixel Dy: the diameter of the suture FS: imaging surface IM, IM0: imaging image L10: The distance between the observation object and its surroundings in the vertical direction LA: illuminating optical axis LD: irradiation direction LS: Lens optical system Ld: Lymphatic vessels Nd: Display pixel number Ni: Number of permutations of camera pixels OA: camera optical axis OD: camera direction OR: observation area OR0: Observable area Px: camera pixel SA: Processing area SB: Observed object SB1: Observe the lower end of the object SC: back wall (observe the surroundings of the object) SD: shadow T: component T1, T2: Tweezers VL: vertical direction HL: horizontal direction O: Origin w': actual field of view W10: the width of the shadow W20: the width of the observation object (observation width) WD: working distance θ: The first tilt angle (observation angle) ψ: second tilt angle

FIG. 1 is a schematic diagram for explaining the configuration of a medical microscope device according to an embodiment of the present invention. Fig. 2 is a medical microscope according to an embodiment of the present invention, Fig. 2(a) is a schematic diagram for explaining an image of an observation area formed on an imaging surface of a solid-state imaging element, and Fig. 2(b) is A schematic diagram for explaining the display image of the display device. 3 is a diagram showing a specific example of an image observed using the medical microscope device according to an embodiment of the present invention. Fig. 4 is a diagram showing a medical microscope device according to an embodiment of the present invention, Fig. 4(a) is an image of the observation state of the suture thread, and Fig. 4(b) is a part of Fig. 4(a) Zoomed in image. Fig. 5 is a partially enlarged image of the image shown in Fig. 4(b). Fig. 6 is a partially enlarged image of the image shown in Fig. 5. Fig. 7 is a schematic diagram for explaining another configuration of the medical microscope device according to an embodiment of the present invention. Fig. 8 is an image showing an observation area of 30.72 mm in width and 17.28 mm in length taken by the medical microscope device according to an embodiment of the present invention. Fig. 9 is an image showing the result of suturing a lymphatic vessel with a No. 12-0 suture, taken using the medical microscope device according to an embodiment of the present invention. 10 is a schematic diagram for explaining the relationship between the imaging optical axis, the vertical direction, and the irradiation optical axis in the medical microscope according to an embodiment of the present invention. FIG. 11 is a graph showing the relationship between the observation angle θ and the actual depth of field d′ in the first embodiment. FIG. 12 is a graph showing the relationship between the scale pitch of the scale used in the measurement of the actual depth of field d′ in Example 1 and the actual depth of field d′. FIG. 13 is a graph showing the relationship between the observation angle θ and the actual field of view w′ in Example 1. FIG. FIG. 14 is a diagram conceptually showing the relationship between the depth of field d, the actual depth of field d', and the actual field of view w'when the observation angle θ is set. 15(a) is a diagram conceptually showing the relationship between the inclination angle of the imaging optical axis of the solid-state imaging device with respect to the vertical direction, the inclination angle of the irradiation optical axis of the irradiation device with respect to the imaging optical axis, the observation object, and the shadow width Fig. 15(b) is a diagram conceptually showing a part of an image observed from the solid-state imaging device regarding the observation target, the surrounding rear wall, and the shadow. 16 is a graph showing, for each first tilt angle, the change in the shadow width when the observation object is illuminated under the conditions shown in FIG. 15 with respect to the angle of the irradiated optical axis with respect to the imaging optical axis, and represents the observation object , Graph of the case where the vertical distance from the surrounding vertical direction is 1.0 mm. Fig. 17 is a graph showing, for each first inclination angle, the change in the shadow width when the observation object is illuminated under the conditions shown in Fig. 15 with respect to the angle of the irradiation optical axis with respect to the imaging optical axis, and is a graph showing the observation object , Graph of the case where the vertical distance from the surrounding vertical direction is 0.5 mm. 18 is a graph showing, for each first tilt angle, the change in the shadow width when the observation object is illuminated under the conditions shown in FIG. 15 with respect to the angle of the irradiated optical axis with respect to the imaging optical axis, and represents the observation object , Graph of the case where the vertical distance from the surrounding vertical direction is 0 mm.

100: Microscope device for medical use

10: Solid state camera

20: Camera Department

21: Solid-state imaging element

30: Lens optics

40: processing device

41: Cable

42: Cable

50: display device

51: display screen

A: Object

AY: suture

DI: circular image

Dr: The diameter of the observation area OR

Di: The diameter of the imaging image IM

FS: imaging surface

IM, IM0: imaging image

Ld: Lymphatic vessels

LS: Lens optical system

OA: camera optical axis

OR: observation area

OR0: Observable area

SA: Processing area

T1, T2: Tweezers

VL: vertical direction

θ: The first tilt angle (observation angle)

Claims (7)

A medical microscope device includes a solid-state imaging device and a display device, the solid-state imaging device has an imaging unit and a lens optical unit, and the solid-state imaging device captures an image including an observation object, and the display device displays The image taken by the Ministry, and The imaging unit includes a solid-state imaging element in which a plurality of pixels each having a photoelectric conversion element are arranged in a matrix on an imaging surface, When a circular observation area with a diameter of 20 mm is captured by the solid-state imaging device and displayed on the display screen included in the display device, The image of the observation area formed on the imaging surface of the solid-state imaging device is a circle having a diameter with a length of four thousand or more pixels arranged, The observation area becomes a circle whose diameter is represented by more than four thousand display pixels in the display screen of the display device. The medical microscope device according to claim 1, wherein the number of display pixels in the minor axis direction on the display screen of the display device is greater than or equal to the number of pixels in the minor axis direction of the solid-state imaging element. The medical microscope device according to claim 1 or 2, wherein the distance between the observation object and the solid-state imaging device is 200 mm or more. The medical microscope device according to claim 1 or claim 2, wherein the imaging optical axis of the solid-state imaging device is inclined by 15 degrees or more and 60 degrees or less with respect to the vertical direction. The medical microscope device according to claim 1 or claim 2, further comprising an irradiation device that irradiates the observation object, and the irradiation optical axis of the irradiation device corresponds to the inclination angle of the imaging optical axis of the solid-state imaging device. Set according to the vertical distance between the observation object and its surroundings. The medical microscope device according to claim 5, wherein the inclination angle is set so that the width of the shadow of the observation target caused by tilting the irradiation optical axis and the imaging optical axis is the width of the observation target The observation width is less than the maximum length, and is a range corresponding to 1/2 of the maximum length or more. The medical microscope device according to claim 5, wherein when the distance in the vertical direction between the observation object and its surroundings is zero, the inclination angle is 60 degrees or more and 80 degrees or less. As the distance in the vertical direction from the surrounding area increases, the tilt angle setting becomes smaller.

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