Endoscope with sensor for image capture and tissue examination

Abstract

The invention relates to an endoscope with a sensor for image capture and tissue examination. The present invention relates to an endoscope (10) configured for imaging and tissue analysis. For this purpose, the endoscope (10) comprises an image sensor (23) to which a plurality of optics (24, 25, 26) are arranged in order to carry out different tasks, in particular imaging tasks and measurement tasks simultaneously or in chronological stages, with the same image sensor (23).

Description

Technical Field

[0001] The present invention relates to an endoscope for medical examination and / or treatment of a human or animal body or a tissue section thereof. Background Art

[0002] Endoscopes for examining and treating human or animal patients are known, and the endoscope includes a longitudinal handle that can be inserted into the patient's body.

[0003] For example, EP 2 075 617 A1 discloses an endoscope having an optical device for spectroscopic examination of tissue presented in front of the distal end of the endoscope. For this purpose, the endoscope includes a through hole at its distal end, serving as a light incident window. By means of a piezoelectric element, a variable filter can be affected so that the wavelength of the transmitted light can be modified. In addition, an illumination device and an image capture device arranged in the endoscope housing are part of the endoscope. Thus, the endoscope allows spectroscopic analysis of the captured light.

[0004] EP 2 725 967 B1 discloses a method for tissue determination based on spectroscopic measurement.

[0005] In addition, the expert article "D-printed miniature spectrometer for the visible range with a 100 x 100 μm2 footprint" by Andrea Toulouse, Johannes Drozella, Simon Thiele, Harald Giessen and Alois Herkommer, https: / / doi.org / 10.37188 / lam.2021.002, discloses a miniature spectroscopic measurement device.

[0006] Similarly, the expert article "Integrated spectroscopic analysis system with low vertical height for measuring liquid or solid assays" by Yuhang Wan, Saoud A. Al-Mulla, Wang Peng, Kenneth D. Long, Benjamin A. Kesler, Patrick Su, John M. Dallesasse and Brian T. Cunningham, http: / / www.elsevier.com / open -access / userlicense / 1.0 / , discloses a spectroscopic measurement device.

[0007] Another construction type of a spectral measurement device is known from EP 2 284 509 A1.

[0008] A multi-focus lens arrangement directly applied to an image sensor is known from WO 2018 / 072806 A1. The sensor is suitable for capturing images of an object while using different focal lengths simultaneously.

[0009] EP 0 939 894 B1 discloses a micro-spectrometer having an electrical carrier plate on which a light source and a light capture element are arranged. This arrangement is embedded in a transparent block on which two lenses of different types are formed.

[0010] WO 2010 / 129324 discloses an endoscope having a working channel and a transparent end cap arranged at the distal end. Through the end cap, the operating field of view can be illuminated by means of an LED light source. In addition, in addition to the associated lens, the end cap of the endoscope further includes a plurality of optical components, such as optical fibers or image sensors.

[0011] US 2005 / 0154277 A1 also discloses a system having a plurality of lenses, however, a plurality of image sensors are assigned to these lenses. The optical device can be part of a capsule that a patient can swallow for examination of the gastrointestinal tract.

[0012] US 2009 / 0147076 A1 discloses an endoscope having an optical device arranged at the distal end for capturing images in multiple directions, and a rectangular image sensor arranged at the proximal end of the endoscope. Images from different lenses are projected onto different areas of the image sensor.

[0013] US 2010 / 0141380 A1 discloses an authentication method and a fingerprint sensor suitable for this purpose. The fingerprint sensor includes an optical window having a flat top surface for placing a finger thereon and a back surface having a serrated profile. The elements of the serrated profile form a series of prisms. A light source is used for illumination of the back surface. A first lens for creating an image on a CCD sensor and a second lens having a diffraction grating for imaging the spectrum of the light reflected by the finger are provided near the light source. The sensor includes a first area and a second area, and the image of the finger is projected onto the first area and the spectrum is projected onto the second area. Summary of the Invention

[0014] The object of the present invention is to provide an endoscope that can be used for diagnosis.

[0015] This object is solved by an endoscope for medical examination and / or treatment of a human or animal body according to claim 1:

[0016] The endoscope according to the invention comprises at its distal end a light-capturing device and an illumination device. The light-capturing device comprises at least one imaging first optical device which is configured to capture a video stream or alternatively individual photographs. An image sensor, in particular an image sensor in the form of a rectangular camera chip, is part of the light-capturing device. Particularly suitable are image sensors in MOS or CMOS technology.

[0017] The first optical device comprises an objective lens consisting of at least one optical element (for example, a lens) which is configured to project a camera image onto a first area of the image sensor. Thus, the first area of the image sensor is assigned to the first optical device. This area can have an angular form or particularly can also be circular, for example, in circular form. The first area is the image-capturing area. The image sensor can in particular be a rectangular image sensor. Its aspect ratio can be, for example, 16:9. The first area can also be rectangular, however with a different aspect ratio, for example, 4:3 or 1:1 or others. In addition, the first area can have a form different from a rectangular form and can be, for example, polygonal or circular.

[0018] Additionally, the light-capturing device comprises a second optical device to which a second area of the image sensor is assigned. This second area can be used for measurement purposes, whereby it forms a measurement area. The measurement area and the first area (imaging area) are arranged adjacent to each other on the image sensor. They can have different forms. While the imaging area can be, for example, circular, the measurement area can be configured in an angled manner and can particularly use the edge or corner area of the image sensor.

[0019] Thus, the endoscope according to the invention comprises at its distal end a first optical device serving as an image-capturing device and a second optical device serving as a measurement device. The two optical devices preferably comprise different light-incidence windows and optical components arranged therein, such as an objective lens in the form of a lens, a light-channel gap, an optical grating, a light filter, etc. The image sensor is generally assigned to the two optical devices, wherein different areas of the image sensor are assigned to the first optical device and the second optical device.

[0020] Preferably, both optical devices are configured in such a way as to define their respective optical axes, wherein these two optical axes are additionally preferably oriented parallel to each other. Alternatively, they can be oriented in a converging orientation in the distal direction away from the distal end of the endoscope. Due to these measures, the imaging optical device and the measurement optical device can be aligned to the same tissue area. In this way, for example, measurements of tissue properties can be carried out while monitoring the tissue defining the operating area.

[0021] The second optical device for measurement purposes may include two light-incident windows spaced apart from each other, and different second sub-regions of the image sensor are assigned to these two light-incident windows. Preferably, the two light-incident windows of the second optical device are arranged on one side of the first optical device, while the light-emitting window of the assigned illumination device is arranged on the other side of the first optical device.

[0022] The light trapping device may have a third optical device, and at least one third region on the image sensor is assigned to this third optical device. The third optical device may be configured to perform a measurement task different from that of the second optical device.

[0023] The third optical device may include a separate light-incident window with a suitable objective lens or other optical components and may be configured for the desired measurement purpose. For example, the third optical device may be a device for performing tissue examination.

[0024] The second optical device and / or the third optical device may be configured to perform diffuse reflectance spectroscopy measurement. To perform the measurement, the distal end of the instrument, especially its light-emitting window, is brought into contact with the tissue. Thus, sub-regions of the image sensor at different distances from the light source can measure tissue arranged at different depths. The light source may be configured in a narrow-band or broadband illumination mode. The emitted light may be all or part in the visible light range or all or part in the infrared light range. Information from and about tissue layers at deeper positions can be obtained.

[0025] The second optical device and / or the third optical device may alternatively be configured to perform scattered light measurement. Thus, tissue slices at different distances from the light source are illuminated with different brightnesses by a probe at a certain distance from the tissue, so that differential measurement of the light scattered by the tissue can be performed. Therefore, light is emitted towards the tissue at a certain distance, and depending on the degree of surface scattering, different intensities can be measured at different distances from the light source.

[0026] The third optical device for measurement purposes may, for this purpose, have two light-incident windows spaced apart from each other, and different third sub-regions of the image sensor are assigned to these two light-incident windows. Preferably, these two light-incident windows of the third optical device are arranged on both sides of the first optical device. However, the light-emitting window of the assigned illumination device is arranged only on one side of the first optical device. Two different third regions of the image sensor are arranged at a certain distance from each other. For example, they may be arranged adjacent to the opposite edges of a rectangular image sensor respectively. In addition, the two light-incident windows of the third optical device may be arranged at different distances from the light-emitting window of the illumination device. This allows differential measurement of tissue characteristics.

[0027] Another optical device can be reserved for another measurement method, and another area of the image sensor can be assigned to this optical device. In particular, the additional optical device can be configured for performing microscopy or micro-measurement methods. Alternatives are possible. For example, the device can be configured for distance measurement or for other measurement tasks.

[0028] The illumination device includes at least one light source, and the light emission direction of the light source is preferably substantially parallel to the optical axis of the first (imaging) optical device. The light source can be used for image capture and for performing tissue measurements. It can be provided that the light source has a larger emission angle than the capture optical device.

[0029] With respect to the photosensitivity of the image sensor, the bandwidth of the light source can be at least as large as the bandwidth of the image sensor. However, one or more light sources can also be provided that only emit light with a bandwidth smaller than the sensitive bandwidth of the image sensor, and thus only serve a part of the image sensor. These light sources can be configured to be turned on and off depending on the measurement task, so as to temporarily perform different measurement tasks simultaneously or subsequently. The light source can be configured in particular to emit visible light as well as infrared light. This spectral range can be provided by a single light source or can be distributed among multiple light sources.

[0030] The imaging area is preferably arranged, for example, between two measurement areas assigned to the second optical device. The second optical device can be configured as a spectrometer. Similarly, if required, a third optical device can be provided, which is a spectrometer or a differential optical measurement device. Due to the different spatial arrangements or different configurations of different optical devices in terms of spectral sensitivity, their uses can be utilized to solve different measurement tasks. For example, the third optical device can be configured for performing diffuse reflectance spectroscopy measurements. For the purpose of spectral filtering, the third optical device can include a plurality of filters arranged next to each other or filters with position-dependent colors, which perform spectral filtering on the received light, for example, in the wavelength range of 600 nm to 900 nm. The filters used for this purpose can be directly applied to the image sensor. Alternatively, one or more diffractive optical elements, such as prisms or gratings, can be arranged at a certain distance from the sensor.

[0031] In addition, the illumination device can have elements for structured illumination of the tissue, for example, in the form of a grating or other pattern. For this purpose, the illumination device can include a laser diode, in particular an infrared laser diode, to which a diffractive optical element is assigned to project the light pattern onto the tissue. If this occurs in the infrared range, the light pattern is invisible to the user. However, in this way, a 3D model of the tissue surface can be created.

[0032] Two different optical devices can be assigned to the same area of the image sensor. For example, the imaging area (the first area) of the sensor can be used simultaneously for imaging with visible light and for forming a 3D model with infrared structured light. In addition, other areas of the image sensor can be used in a variety of ways.

[0033] The image sensor is preferably an RGB-IR sensor. Such a sensor includes photosensitive elements (pixels) that are distributed on its rectangular photosensitive surface and arranged in a grid. Therefore, preferably, the photosensitive elements for blue light, green light, red light, and infrared light are alternately distributed above the surface of the sensor in a suitable manner. For this purpose, a color filter matrix (Bayer matrix) for color display has already been applied by the manufacturer to the actual image sensor. In all areas of the image sensor, that is, in the imaging area and the measurement area, the arrangement of the individual photosensitive elements is preferably the same. The color filter matrix can extend over the first area for imaging and the second or third area for measurement purposes. Alternatively, the color filter matrix can also be omitted in the second and / or third area, or if provided by the manufacturer, it can also be removed subsequently.

[0034] The image sensor can include pixels that are sensitive to two, three, four, or more different light wavelengths (i.e., colors), and thus can analyze light with the corresponding spectral resolution. Therefore, in an image sensor with pixels sensitive to four different colors, four different spectral lines (i.e., light components) of the received light can be distinguished.

[0035] In addition, a large number of spectral lines can be detected using the same image sensor, and this number is significantly higher than the number of colors that the image sensor itself can distinguish. This can be implemented particularly by using a multi-bandpass filter, which allows light with different colors (i.e., light in multiple different wavelength ranges) to pass through and absorbs or reflects it otherwise. Preferably, two or more multi-bandpass filters can be used, which are distinguishable from each other in their colors and are arranged in the optical path, for example, directly on the image sensor, to cover larger groups of pixels that are directly adjacent to each other or are close to each other at a certain distance.

[0036] The different color components of light passing through the multi-bandpass filter impinge uniformly on different color pixels of the image sensor. The pixels are sensitive (sensitivity range) to different (e.g., four) wavelength ranges (color ranges). The sensitivity ranges can overlap. For this reason, it can happen that light of a single color activates two types of pixels adjacent to each other in wavelength of the image sensor. It can also happen that two or more pass ranges of the multi-bandpass filter are provided within one sensitivity range of the image sensor type. If multiple pass ranges of the multi-bandpass filter are present within the same sensitivity range, then by means of calculation, it is possible to particularly easily assign the light received by pixels of the same type to different spectral lines if there is only one pass range within the sensitivity range and no pass range of the same multi-bandpass filter is present within an adjacent overlapping sensitivity range. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Advantageous embodiments of the invention and additional details of the details can be derived from the drawings, the description, and the claims. The drawings show:

[0038] Figure 1 Schematic illustration of an endoscope according to the invention,

[0039] Figure 2 According to Figure 1 Schematic front view illustration of the endoscope,

[0040] Figure 3 According to Figure 1 and Figure 2 Schematic top view illustration of the image sensor and the illumination device of the endoscope,

[0041] Figure 4 Pixel arrangement of the image sensor of the endoscope,

[0042] Figure 5 Optical conditions during tissue examination using the endoscope tip placed on the tissue, and

[0043] Figure 6 Use of the endoscope at a position away from the tissue during imaging,

[0044] Figure 7 According to Figure 1 and Figure 3 Image sensor of the endoscope having an image area and a filter for configuring a multi-channel spectrometer,

[0045] Figure 8 Without filter Figure 7 Image sensor of

[0046] Figure 9The first figure for illustrating the pass range of the first filter and the sensitivity range of the image sensor,

[0047] Figure 10 The second figure for illustrating the second pass range of the filter and the sensitivity range of the image sensor,

[0048] Figure 11 The figure for illustrating the spectral lines that can be detected by means of the image sensor. Detailed Description

[0049] In Figure 1 , the endoscope 10 according to the present invention is depicted in an overview. The endoscope 10 includes a distal end 11 which will be inserted into a patient's body, for example, into a body cavity of the patient, during the performance of an operation. The endoscope is then controlled from the proximal end 12, on which one or more operating elements 13 may be provided. Depending on the configuration of the endoscope 10, such operating elements 13 can be used to move, in particular, for example, to bend a part of the distal end 11. The longitudinal handle 14 of the endoscope is separated therefrom and can be rigid or, if necessary, also flexible.

[0050] The endoscope can have one or more working channels 15 which extend all the way to the face 16 of the handle 14, where the face 16 is configured in a planar or dome-shaped manner. One or more working channels 15 are used to position probes or instruments (not further illustrated) therein, which serve as tools for affecting biological tissue. Such instruments can be, for example, high-frequency surgical instruments, cryosurgical instruments or other tools suitable for affecting tissue.

[0051] The endoscope 10 according to the present invention includes extended optics 22, which will be explained with reference to Figures 2 to 6 it. The optics 22 is located in the distal part 17 of the distal end 11, which is itself stable in form and, therefore, has a substantially cylindrical configuration regardless of whether the handle 14 is rigid or flexible. However, the face 16 can be dome-shaped and, therefore, is configured, for example, in a hemispherical manner. Other shapes are also possible, in particular a substantially planar configuration with a smoothly transitioning part to the cylindrical circumferential surface, and can be conveniently used for the specific measurement tasks explained below.

[0052] The part of the optics arranged in the end part 17 is first of all the illumination device 18, which includes at least one (but possibly multiple, for example, two or three) light sources 19, 20, 21, shown by means of their light exit windows in Figure 2 . The light sources 19, 20, 21 can be light sources with the same optical characteristics. However, in particular, they can also be light sources with different characteristics. These differences may relate to:

[0053] - Bandwidth and / or

[0054] - The spectral composition of the emitted light,

[0055] - The spatial distribution of the light, e.g., with respect to

[0056] - The opening angle or

[0057] - The created light pattern or

[0058] - Temporal characteristics, such as

[0059] - Continuous light,

[0060] - Intermittent light and

[0061] - The activation time points of each light source.

[0062] For example, the first light source 19 can be a light source for the red to infrared wavelength range (e.g., from 600 nm to 900 nm). The second light source 20 can be, for example, a white light source for the visible light wavelength range, or a colored light source within the visible light range. Additionally, the second light source can be a light source including at least part of the visible light range and at least part of the infrared range. Additionally, the second light source can be a pure infrared light source. The light source 21 can be a white light source. It can be configured to uniformly illuminate the operation area. Alternatively, it can be configured to only illuminate a sub-region. In particular, it can be configured as a projection device and can be configured to create an image or a light pattern so as to project, for example, a line image, a grid image, or another still or moving image onto the tissue located in front of the distal end 11 of the endoscope.

[0063] The light sources 19, 20, 21 can have a consistent light emission direction (optical axis), or different light emission directions. In a preferred embodiment, at least one of the three light sources 19, 20, 21 includes a light emission direction consistent with the longitudinal direction of the handle 14. Preferably, the light emission directions of two light sources or all three light sources are oriented parallel to each other. The opening angles of the light cones emitted from the light sources 19, 20, 21 can have similar sizes, or different sizes. Thus, one or more of the light sources 19, 20, 21 can respectively have a conical light emission with a circular light emission surface. One or more of the light sources 19, 20, 21 can also define a light emission surface deviating therefrom, e.g., an elliptical, semi-circular, or rectangular light emission surface.

[0064] The illumination device 18 is part of a sensor device suitable for image capture and performing measurements on tissue. In addition to the illumination device 18, the sensor device further includes a light capture device 22. The light capture device 22 includes in Figure 3The image sensor 23 shown separately in the figure. The image sensor 23 can be a so-called camera chip, which has a plurality of photosensitive units (so-called pixels) arranged in a predetermined grid. Each pixel is typically sensitive to different light colors (e.g., blue, green, and red) respectively. In addition, in a preferred embodiment, there are infrared-sensitive pixels. Therefore, Figure 4 The pixels in are characterized by "B" for blue, "G" for green, "R" for red, and "IR" for infrared light. It is an RGB-IR sensor.

[0065] A plurality of optical devices 24, 25, 26 are assigned to the image sensor 23, and these optical devices are shown in Figure 2 based on their light incident windows arranged on the surface 16.

[0066] The first optical device 24 is an imaging device. It includes Figure 5 and Figure 6 the objective lens 27 shown by means of the lens 28 in. However, the objective lens 27 can include other and / or additional optical elements. The objective lens 27 is an imaging objective lens and is configured to project an object image onto the first area 29 of the image sensor 23. As Figure 3 shown, the area 29 can have a form deviating from the circumference of the image sensor 23 and can be in particular circular, square or rectangular, for example, with an aspect ratio of 4:3. Preferably, the area 29 is arranged approximately in the center of the image sensor 23.

[0067] Between the narrow side 30 of the image sensor 23 and the area 29, a second area 31 can be provided as a measurement area. The second area 31 can be divided into a plurality of sub-areas, for example, two sub-areas 311 and 312 arranged between the first area 29 and the narrow side 30. The first area 29 is an imaging area, while the second area 31 is a measurement area.

[0068] At least one of the light sources 19, 20, 21 is assigned to the first optical device 24. For example, the light source 21 can be used to emit light for irradiating the tissue surface 32 ( Figure 6 ), where the first optical device 24 is then used to capture the corresponding image. However, the same or another light source (e.g., the light source 19) can be assigned to the second optical device 25. Although the light source 19 (or 20 or 21) is arranged on one side of the center line E passing through the first optical device 24 and the working channel 15, the optical device 25 is preferably arranged on the other side of the line E. The device 25 can include one or two light incident windows 251, 252 arranged next to each other, which receive light and guide it to the sub-areas 311, 312 of the image sensor 23.

[0069] In Figure 2 and Figure 3Another possibility of the light source arrangement is depicted, for example, the light incident windows 261, 262 of the light source 20 and the third optical device. Assigned to the light incident windows 261, 262 of the third optical device 26 is the third region 33 of the image sensor 23, and this third region 33 can in turn include two sub-regions 331, 332. Preferably, the two sub-regions 331, 332 are arranged on both sides of the imaging region 29. Thus, the measurement region or its parts 331, 332 are provided on both sides of the imaging region 29.

[0070] In addition, in the remaining part of the image sensor 23, a fourth measurement region 34 can be provided, and a separate objective lens 35 is also assigned to this fourth measurement region, which can be used for microscopy, for example.

[0071] Thus, on the rectangular image sensor 23, at least one region 29 for imaging and at least one additional region are provided. Preferably, a plurality of additional regions 31, 33, 34 are provided for measuring tissue characteristics. Although the imaging region 29 is preferably symmetrically arranged, which means centered on the image sensor 23, the regions 31, 33, 34 of the image sensor 23 suitable for performing the measurement tasks can be arranged symmetrically or asymmetrically on both sides of the imaging region 29.

[0072] The image sensor 23 is preferably a semiconductor sensor having a plurality of pixels, and it has the same uniform configuration for the imaging region 29 and the measurement regions 31, 33, 34.

[0073] The endoscope 10 described so far can be used differently:

[0074] In Figure 6 is schematically depicted the endoscope 10 or its end portion 17 during imaging. It is at a certain distance from the surface portion 32. The surface portion 32 is irradiated by means of the third light source 21. The tissue image is projected onto the image sensor 23, in particular onto the imaging region 29, via the objective lens 27. Thus, the image sensor 23 creates an image or a video stream. It can be transmitted to the proximal end 12 of the endoscope by means of components not further illustrated here, and from there towards an image display device, such as a VR glasses, a screen, etc.

[0075] If the light source 21 is a light source for structured illumination, or if it can be switched to emit structured light, it can be used to project a light pattern onto the tissue surface 32. The resulting image can be supplied to an image processing device, which thereby calculates a 3D model of the tissue surface 32 and provides it for rendering.

[0076] The light source 21 can be configured to emit unstructured light in the visible light range and structured light in the infrared light (invisible light) range. In this way, on the one hand, the image sensor 23 can create an optical image for the surgeon to represent, and on the other hand, create an infrared image from which the image processing device can determine a relief image, which means a 3D model of the tissue surface 32, and provide this 3D model for further processing or observation.

[0077] Figure 5 The figure shows an operating mode in which imaging is not performed, but tissue measurement is performed. For this purpose, the distal end face 16 of the endoscope 10 is placed on the tissue surface 32. The cooperation of the light source 20 with the two parts 261, 262 of the optical device 26 is taken as an example to explain this operation. For example, the light source 20 emits broadband infrared light, which enters the tissue and scatters there. The light reaches the light incident windows of the two parts 261, 262 along paths W1, W2 of different lengths. Since the path W2 is longer, the light signal received by the sub-region 331 has scattered in a deeper tissue layer away from the surface. Therefore, by comparing these two signals, the scattering of the tissue, the type of the irradiated tissue layer can be determined, and in this way, the proximity to the organ can also be determined. This is particularly applicable when the organ located in the tissue has different light scattering characteristics from the surrounding embedded tissue. In addition, due to the different wavelengths of light, the degree of light absorption is also different. If the current tissue type includes a homogeneous structure, then in addition, scattering and absorption can also be distinguished by means of spatial differential measurement.

[0078] To perform this differential diffuse reflectance spectroscopy measurement, alternatively, a light source can be provided, preferably infrared light with a not-too-narrow frequency band, or visible colored light or white light, or light including parts in the visible spectrum and the infrared spectrum range.

[0079] At least one of the regions 31, 33 for measurement purposes or at least one of its sub-regions 311, 312, 331, 332 can be configured to perform spectroscopic measurement tasks. For this purpose, spectroscopic filtering elements can be applied or arranged relative to each of the regions 31 and / or 32 for measurement. In the simplest case, narrowband color filters 333, 334 ( Figure 5 ), for example, interference optical filters, are directly applied to the image sensor 23, and a filter for a selected wavelength is provided for each individual pixel or pixel group. In this way, spectroscopic analysis can be performed on the light scattered back from the tissue surface 32 while imaging. A so-called linear variable filter can also be provided instead of the individual filters arranged next to each other, and the pass wavelength of this linear variable filter varies along a line (preferably a straight line).

[0080] With the endoscope 10 according to the present invention, different measurement tasks can be carried out simultaneously or subsequently. If the endoscope 10 is positioned such that its face is away from the tissue surface 23, the following operations can be carried out:

[0081] - Imaging by means of the first optical device 24,

[0082] - 2D imaging using visible light and simultaneously 3D detection by means of structured illumination using infrared light,

[0083] - Imaging by means of the optical device 24 and differential diffuse reflectance spectroscopy using the third optical device 26,

[0084] - Imaging by means of the optical device 24 and microscopy using the fourth optical device 35,

[0085] - Imaging by means of the optical device 24, diffuse reflectance spectroscopy using the third optical device 26, and microscopy using the fourth optical device 35.

[0086] However, if the endoscope 10 is placed such that its face is on the tissue surface 23, the following operations can be carried out:

[0087] - Diffuse reflectance spectroscopy using the second optical device 25, and / or

[0088] - Diffuse reflectance spectroscopy using the third optical device 26.

[0089] As described above, different from the imaging area 29, the areas in the image sensor 23 that are not used for imaging can be used for measurement purposes. Therefore, spectroscopic measurements can be carried out by means of the image sensor 23. Particularly advantageous possibilities for this are disclosed in Figures 7 to 11 where at least one of the measurement areas 31, 33, 34 is used as a spectrometer and is thus specifically configured as a spectrometer suitable for analyzing diffuse light.

[0090] The image sensor 23 includes a plurality of pixels B (blue), G (green), R (red), IR (infrared) that are sensitive to different wavelength ranges. They can be arranged according to the Figure 4 scheme or another scheme. In addition, the image sensor 23 can also include different numbers of pixel types, for example, only two or three. The sensitivity ranges of the individual pixels B, G, R, IR are illustrated in Figure 9 and Figure 10 . Obviously, all sensitivity ranges have a maximum value respectively, whereby the photosensitivity of the corresponding pixels B, G, R, IR decreases towards both sides of the maximum value. As in Figure 9 and Figure 10As shown, the sensitivity ranges of adjacent pixels B / G and G / R can significantly overlap.

[0091] Two filters F1, F2 are part of the spectrometric measurement area 34 and are not arranged in an overlapping manner. They can be arranged on the image sensor 23, either directly adjacent to each other or at a certain distance from each other. Filter F1 is a first multi-bandpass filter that allows light to pass through in passbands a, d, e, and h, Figure 9 shown in an idealized manner in, but absorbs or reflects light of other wavelengths. In Figure 10 shown is the transmission characteristic of the second multi-bandpass filter F2, shown in an idealized manner, which allows light to pass through in passbands b, c, f, and g, while other wavelength ranges are blocked, absorbed, or reflected.

[0092] Now, during light evaluation, there are two pixel groups, namely the group of pixels B, G, R, IR illuminated by the light of the multi-bandpass filter F1, and the second group with pixels B, G, R, IR illuminated by the light of the multi-bandpass filter F2. It can be clearly seen from Figure 9 that, for example, light in passband e can induce signals in pixel G and pixel R of the group of pixels under filter F1. Similarly, light in passband c can induce signals in pixels B and G of the group under filter F2. Although light in both passbands d and e activates the green-sensitive pixel G, and although light from passbands b, c activates the blue-sensitive pixel B, the spectral components of passbands d, e and the spectral components of passbands b, c can be separated from each other. This is demonstrated below by an example of the intensity I of the spectral components of passbands c and e respectively existing in the overlapping range: Particularly simply, the separation of the spectral components of passbands d and e of filter F1, because in the overlapping range, in addition to passband e, there is only one adjacent passband d. Further, because in one of the adjacent sensitivity ranges of pixels G and R, there is no passband of the same filter F1, and in the other of the adjacent sensitivity ranges of pixels G and R, there is no passband. Passband f is assigned to the second filter F2 and can be read unbiasedly on the red pixel R.

[0093] Similarly, the light in passbands b and c under filter F2 activates both pixels B and G. However, for pixel B only, there is an additional passband b. However, the green pixel G only receives light from passband c, while the light from passband d is obtained via the pixels of the first filter region F1.

[0094] The intensities I of passbands c and e can be determined as follows:

[0095] It is known from the data table that at the wavelength of the passband c, the signal relationship between pixels B and G in the overlapping range, and is represented here as Fc 处 GB 之间 。 To obtain the intensity of Bc 处 the signal Gc provided for the green pixel G for the passband c 处 is multiplied by the factor Fc 处 GB 之间 。 The signal or intensity Ic and Ib can be calculated as follows:

[0096] Bc 处 = G·Fc 处 GB 之间

[0097] Ic = Bc 处 + G

[0098] Ib = B - Bc 处

[0099] Ge 处 = R·Fe 处 RG 之间

[0100] e = Ge 处 + R

[0101] d = G - Ge 处

[0102] Thus obtained Figure 11 the spectrum shown with eight spectral lines. On the additional surface area of the image sensor 23, additional multi-bandpass filters can be provided to further improve the spectral resolution. The condition for this is that in the overlapping range, the spectral sensitivity ratio of adjacent pixels in terms of their wavelength is known, and there is only one multi-bandpass double occupancy for each channel (RGB). These double occupancies are d and e in Figure 9 and b and c in Figure 10 . It would be helpful if there is no channel occupancy (no pass range for the corresponding filter) for the same or at least one of the corresponding other filters in adjacent color channels (here R and G).

[0103] The present invention relates to an endoscope 10, which is configured for imaging and tissue analysis. For this purpose, the endoscope 10 includes an image sensor 23, and a plurality of optical devices 24, 25, 26 are arranged on the image sensor 32 so as to perform different tasks using the same image sensor 23, in particular, imaging tasks and measurement tasks are performed simultaneously or hierarchically in chronological order.

[0104] List of reference signs:

[0105] 10 Endoscope

[0106] 11 Distal end of endoscope 10

[0107] 12 Proximal end of endoscope 10

[0108] 13 Operating element of endoscope 10

[0109] 14 Handle of endoscope 10

[0110] 15 Working channel of endoscope 10

[0111] 16 Face of handle 14

[0112] 17 End portion

[0113] 18 Irradiation device

[0114] 19 First light source

[0115] 20 Second light source

[0116] 21 Third light source

[0117] 22 Light trapping device

[0118] 23 Image sensor

[0119] R Red-sensitive pixel

[0120] G Green-sensitive pixel

[0121] B Blue-sensitive pixel

[0122] IR Infrared-sensitive pixel

[0123] 24 First optical device

[0124] 25 Second optical device

[0125] 251, 252 Components of the second optical device

[0126] 26 Third optical device

[0127] 261, 262 Components of the third optical device

[0128] 27 Objective lens of optical device 24

[0129] 28 Lens of objective lens 27

[0130] 29 First region (imaging region)

[0131] 30 Narrow side

[0132] 31 Second region (measurement region)

[0133] 311, 312 Sub-regions of the second region 31

[0134] 32 Tissue surface

[0135] 33 Third region (measurement region)

[0136] 331, 332 Sub-regions of the third region 33

[0137] 333, 334 Color filters

[0138] F1 First multi-bandpass filter

[0139] F2 Second multi-bandpass filter

[0140] a - h Passbands of the filters F1, F2

[0141] 34 Fourth region (measurement region)

[0142] 35 Objective lens

Claims

1. An endoscope (10) for medical examination and / or treatment of a human or animal body, having a longitudinal handle (14) comprising an illumination device (18) and a light capturing device (22) at its distal end (11), Features The light capturing device (22) comprises at least an imaging first optical device (24) and a second optical device (25), to which a first area (29) and a second area (31) of a common image sensor (23) are assigned, so as to define an imaging area (29) and at least one measuring area (31) different from the imaging area (29) on the image sensor (23).

2. The endoscope according to claim 1, characterized in that The first optical device (24) and the second optical device (25) are configured to define an optical axis respectively.

3. The endoscope according to claim 2, characterized in that The two optical axes are defined to be parallel to each other.

4. An endoscope according to any of the preceding claims, characterized in that The light capturing device (22) comprises a third optical device (26), to which at least one third area (33) on the image sensor (23) is assigned, forming another measuring area different from the imaging area (29).

5. An endoscope according to any of the preceding claims, characterized in that The second optical device (25) comprises two light entrance windows (251, 252), to which different second areas (311, 312) of the image sensor (23) are assigned.

6. The endoscope according to claim 5, characterized in that The two light entrance windows (251, 252) are arranged at different distances from the illumination device (18).

7. An endoscope according to any of the preceding claims, characterized in that The illumination device (18) comprises at least one light source (19, 20, 21) having a light emission direction (A2) defined as being parallel to the optical axis (A1) of the first optical device (24), whereby the illumination device (18) comprises at least one light source (21) arranged at a lateral distance from the first optical device (24).

8. An endoscope according to any of the preceding claims, characterized in that The imaging region (29) is arranged between two measuring regions (31 / 34; 331, 332).

9. An endoscope according to any of the preceding claims, characterized in that The second optical device (25) is configured to perform spectrometric measurements and / or to perform differential optical measurements.

10. An endoscope according to any of the preceding claims, characterized in that The second optical device (25) is arranged relative to the first optical device (24) using sub-regions (251, 252) arranged asymmetrically on the image sensor (23), and / or the third optical device (26) is arranged relative to the first optical device (24) using sub-regions (261, 262) arranged symmetrically on the image sensor (23).

11. An endoscope according to any one of claims 9 or 10, characterized in that At least two color filters (333, 334, F1, F2) matched to different wavelengths are applied to the image sensor (23) to form a spectrometer.

12. The endoscope according to claim 11, characterized in that The image sensor (23) comprises a plurality of pixels (R, G, B, IR) sensitive to different wavelength ranges and preferably arranged in a periodic pattern, and the color filters (F1, F2) are respectively provided with a plurality of passbands (a, d, e, h; b, c, f, g) of multi-bandpass filters.

13. The endoscope according to claim 12, characterized in that: At least two of the wavelength ranges of the different pixels (R, G, B, IR) overlap each other, so that light having a wavelength in the overlapping range generates a signal in both pixels that are sensitive to said overlapping range.

14. The endoscope according to claim 12 or claim 13, characterized in that: At least one of the multi-bandpass filters (F1, F2) comprises at least one passband (e, c) provided between adjacent wavelength ranges of respective pixels (R, G, B, IR).

15. The endoscope according to claim 11 to claim 14, characterized in that: The color filters (F1, F2) configured as multi-bandpass filters are arranged in such a way as to respectively cover a group of a plurality of pixels (R, G, B, IR) sensitive to different wavelength ranges, wherein each group comprises a plurality of pixels for each wavelength range.

Images