WO2024047026A1

WO2024047026A1 - Endoscope device, correction pair arrangement, endoscope and imaging system

Info

Publication number: WO2024047026A1
Application number: PCT/EP2023/073638
Authority: WO
Inventors: Sebastian Barth; Robin Hegenbarth
Original assignee: Karl Storz Se & Co. Kg
Priority date: 2022-08-31
Filing date: 2023-08-29
Publication date: 2024-03-07

Abstract

The invention relates to an endoscope device (110) comprising a lens arrangement (112) which is configured to image light both in the visible range and in the near infrared range and is symmetrical with respect to a first plane of symmetry (120) perpendicular to the optical axis (114). The lens arrangement (112) comprises six rod lenses (122) and two correction elements (124), which each comprise a lens system (128) having a first lens (130) and a second lens (132). The first lens (130) is manufactured from a first glass and the second lens (132) is manufactured from a second glass. The first glass and the second glass have different Abbe numbers, with relative partial dispersions of the first glass and the second glass deviating from glass with normal dispersion in the opposite sense. The lens arrangement (112) also comprises a correction pair arrangement (134) which comprises two of the correction elements (124) symmetrical with respect to one another in relation to a second plane of symmetry (136) perpendicular to the optical axis (114).

Description

Endoscope device, correction pair arrangement, endoscope and imaging system

The invention relates to an endoscope device, in particular for hyperspectral and/or multispectral imaging, a correction pair arrangement for a lens arrangement of an endoscope, an endoscope and an imaging system with an endoscope.

Lens arrangements for endoscopes which have several rod lenses are known from the prior art. Such lens arrangements are combined with an objective and an eyepiece. Light that falls into the objective from an observed object can be transmitted through the lens arrangement to the eyepiece. This allows the observed object to be imaged in a known manner.

In the field of endoscopy, endoscopic devices that generate multispectral or hyperspectral images are increasingly being used. In addition to two spatial dimensions, such as those of a conventional image from a camera, multispectral or hyperspectral images also have a spectral dimension. The spectral dimension includes several spectral bands (wavelength bands). Multispectral and hyperspectral images differ essentially in the number and width of their spectral bands. In principle, such systems can also be suitable for carrying out fluorescence recordings.

Some imaging devices are known for generating such multispectral or hyperspectral images, particularly in the context of medical applications. DE 20 2014 010 558 Ul, for example, describes a device for recording a hyperspectral image of an examination area of a body. An input lens for generating an image in an image plane and a slit-shaped aperture in the image plane for masking out a slit-shaped area of the image are arranged in the device. The light passing through the aperture is fanned out using a dispersive element and a camera sensor recorded . This allows the camera sensor to record a large number of spectra, each with an assigned spatial coordinate, along the longitudinal direction of the slot-shaped aperture. The device described is furthermore designed to record further spectra along the longitudinal direction of the slit-shaped aperture in a direction different from the longitudinal direction of the slit-shaped aperture. The method for generating multispectral or hyperspectral images on which this disclosure is based is also known as the so-called pushbroom method.

In addition to the pushbroom method, there are other methods for generating multispectral or hyperspectral images. In the so-called whiskbroom method, the examination area or object is scanned point by point and a spectrum is obtained for each point. In contrast, the staring process takes several images with the same spatial coordinates. Different spectral filters and/or lighting sources are used from image to image to resolve spectral information. There are also methods according to which a two-dimensional multi-color image is broken down into several spectral individual images using suitable optical elements such as optical slicers, lenses and prisms, which are recorded simultaneously on different detectors or detector areas. This is sometimes referred to as the snapshot approach.

As described in DE 10 2020 105 458 A1, multispectral and hyperspectral imaging devices are particularly suitable as endoscopic imaging devices. In this context, multispectral and/or hyperspectral imaging is a fundamental field of application, for example for diagnostics and for assessing success or a quality of an intervention.

Multimodal endoscope devices make it possible to optionally record white light images and/or multispectral images and/or fluorescence images and/or hyperspectral images.

For the applications mentioned, it is advantageous or even absolutely necessary to have light in both the visible range to be able to transmit and image data even in the near-infrared range. Multispectral or hyperspectral imaging, for example, can be used in a particularly versatile manner if work can be carried out in a spectral range between approximately 450 nm and 1000 nm. It is also advantageous for fluorescence imaging if a broad spectral range is available, because the same optical system can then be used to record fluorescence images and white light images. The latter often provide more comprehensive information about the anatomy under consideration, which is why it is advisable to combine them with fluorescence images. In this regard, existing lens arrangements provide an imaging quality that is often not satisfactory over a wide spectral range. It must then regularly be used in parts of the overall spectral range used with a reduced resolution or with poor focus.

In addition, it is regularly unsatisfactory for users to work with focusing optimized for the near-infrared range if this is accompanied by defocusing in the visible range, because the image quality is then subjectively perceived as inadequate.

In practice, in many situations it is not practical for users to adjust a focus of the endoscope device used depending on the respective observation mode. If overlay representations are to be generated, for example by superimposing white light images and fluorescence images or white light images and hyperspectral images/multispectral images on one another, switching may occur automatically and at very short time intervals. Fluorescence imaging and multispectral imaging can be performed in real time. Hyperspectral imaging regularly takes place at least essentially in real time; recording a hyperspectral image data set takes a few seconds, for example. However, all wavelengths are considered in a single image recording, which is why wavelength-dependent adjustment of the focus is not practical. Based on the prior art, the invention is based on the object of enabling high-quality endoscopic images in a broad spectral range.

This object is achieved according to the invention by an endoscope device, a correction pair arrangement for a lens arrangement of an endoscope, an endoscope and an imaging system, as described herein and defined in the claims.

An endoscope device, in particular for hyperspectral and/or multispectral imaging, comprises a lens arrangement that defines an optical axis and that is designed to optically couple an eyepiece to an objective. The lens arrangement is set up, in particular for a given focusing, both in the visible range and in the near-infrared range and in particular both over a large part of the visible range and in the near-infrared range, for an at least essentially equivalent forwarding and / or imaging of light. The lens arrangement is symmetrical with respect to a first plane of symmetry that is perpendicular to the optical axis.

The lens arrangement comprises at least six rod lenses and at least two correction elements, which together with the rod lenses define an optical system and which each comprise a lens system with at least a first lens and a second lens. The first lens is made of a first glass and the second lens is made of a second glass. The first glass and the second glass have different Abbe numbers. A relative partial dispersion of the first glass and a relative partial dispersion of the second glass deviate in opposite ways from normal dispersion glass. Furthermore, the lens arrangement comprises at least one correction pair arrangement which comprises two of the correction elements which are symmetrical to one another with respect to a second plane of symmetry which is perpendicular to the optical axis. The invention also relates to a correction pair arrangement for a lens arrangement of an endoscope, comprising at least two correction elements which define an optical axis and which are set up to define an optical system together with a plurality of rod lenses and which each have a lens system with at least one first lens and a second lens. The first lens is made of a first glass and the second lens is made of a second glass. The first glass and the second glass have different Abbe numbers. A relative partial dispersion of the first glass and a relative partial dispersion of the second glass deviate in opposite ways from normal dispersion glass. The correction elements are symmetrical to one another with respect to a plane of symmetry that is perpendicular to the optical axis.

The features according to the invention enable high-quality endoscopic images in a wide spectral range. The inventors have recognized that in order to achieve high imaging quality over a wide spectral range, lens errors must be addressed in a very targeted manner and for this purpose optical components must be suitably selected and combined. Through the use of paired correction elements and the use of suitable symmetry in the structure of the lens arrangement, chromatic aberration can advantageously be reduced in such a way that images with high imaging quality can be recorded both in the visible range and in the near-infrared range without the focus having to be adjusted/adjusted depending on the wavelength . In addition, the inventors have recognized that, particularly for high-quality multispectral or hyperspectral imaging, the highest possible light intensities should be present on appropriate detection sensors, if possible, in the entire spectral range imaged. In addition, the use of rod lenses and additional correction elements enables conventional assembly processes for the production of endoscopes or To use endoscope shafts in which endoscope devices according to the invention or Lens arrangements are used. Known method steps can be used to build the lens system, just the combined ones optical components differ from previous lens arrangements.

The objective can include a lens system that is designed to enable the coupling of light and to forward coupled light to the lens arrangement. The injected light is, for example, light that was remitted and/or emitted by an object to be observed. In particular, it can be remitted illumination light and/or fluorescent light.

In some embodiments, the eyepiece is designed to supply light transmitted by the lens arrangement to an image capture sensor system. The image capture sensor system can be part of an imaging unit, in particular a multimodal imaging unit, by means of which multispectral imaging, hyperspectral imaging, white light imaging and/or fluorescence imaging can be carried out, preferably optionally.

The endoscope device can be part of an endoscope, in particular a medical endoscope. In general, it can be a medical endoscope device. In addition to the endoscope device, the endoscope can include the eyepiece and/or the objective. Alternatively or additionally, the eyepiece and/or the objective can be part of the endoscope device.

Multispectral imaging can in particular refer to such imaging in which at least two, in particular at least three, and in some cases at least five spectral bands can be detected and/or are detected independently of one another. The individual spectral bands for multispectral imaging can be determined by suitable and, if necessary, Switchable optical filters must be defined. Hyperspectral imaging can in particular refer to such imaging in which at least 20, at least 50 or even at least 100 spectral bands can be detected and/or are detected independently of one another. Hyperspectral imaging can, for example, be carried out using the pushbroom method and/or can be carried out using the whiskbroom method and/or the staring method and/or using a snapshot principle.

The rod lenses can in particular be arranged in such a way that their longitudinal axes are arranged parallel to one another and/or parallel to the optical axis of the lens arrangement. The longitudinal axes of the rod lenses and the optical axis preferably coincide. The rod lenses and the correction elements can be arranged in such a way that light that is transmitted and/or imaged through the lens arrangement passes through all rod lenses and all correction elements.

In some embodiments, the lens arrangement can have a length of at least 20 cm, at least 30 cm or even at least 40 cm. The lens arrangement can be rigid. In other words, components of the lens arrangement, for example the at least six rod lenses and the at least two correction elements, in particular all components of the lens arrangement, can be immovable relative to one another.

The endoscope device can further include the eyepiece and/or the objective. The eyepiece and/or the object can/can form an imaging optical system together with the lens arrangement.

The endoscope device can comprise a shaft in which the lens arrangement is received and/or fastened. In this case, the optical axis can be arranged parallel to a longitudinal axis of the shaft and in particular can coincide with it. In other words, the shaft, the rod lenses and in particular the correction elements can be arranged coaxially.

By “a large part of a wavelength range” is meant in particular a, preferably contiguous, wavelength range which covers at least 60%, preferably at least 70%, particularly preferably at least 80% and preferably at least 90% of the reference wavelength range. The visible wavelength range can be in particular the range from 400 nm to 750 nm should be understood. The term “near-infrared range” in this context refers in particular to wavelengths that lie outside the visible wavelength range. In particular, the lens arrangement can be used for a given focusing both over the majority of the visible range and over a large part of at least the range from 800 nm to 1000 nm can be set up for at least essentially equivalent forwarding and imaging of light. In other words, the lens arrangement can be used for a given focusing over a large part of the range from 480 nm to 900 nm and preferably over a large part of the range from 400 nm to 1000 nm an at least essentially equivalent forwarding and imaging of light.

An “at least essentially equivalent transmission of light” is to be understood in particular as meaning that there is an average transmission in the wavelength range mentioned for all pairs of arbitrarily selectable intervals in the wavelength range mentioned, which have a width of at most 100 nm, at most 50 nm or even at most 10 nm, differs between the intervals by a maximum of 30%, preferably by a maximum of 20%, particularly preferably by a maximum of 15% and preferably by a maximum of 10%. An “at least essentially equivalent transmission of light” can include a transmission in the above-mentioned Wavelength range for all pairs of arbitrarily selectable wavelengths in the mentioned wavelength range differs between the wavelengths by a maximum of 30%, preferably by a maximum of 20%, particularly preferably by a maximum of 15% and preferably by a maximum of 10%. “Transmission” here means in particular a degree of transmittance, i.e. a quotient of transmitted and incident intensity. The information relates in particular to those light intensities for which the transmission shows no or at least essentially no intensity dependence.

An “at least essentially equivalent transmission and imaging of light” refers in particular to the fact that the lens arrangement is visible over a large part of the light Can be used in the range as well as in the near-infrared range. In other words, the lens arrangement can be used for a given focusing in both the visible range and the near-infrared range, in particular can be used equally.

A “substantially equivalent transmission of light” can specifically be understood to mean that there is an average transmission in the wavelength range mentioned for all pairs of arbitrarily selectable intervals in the wavelength range mentioned, which have a width of at most 100 nm, at most 50 nm or even at most 10 nm and in which in particular the average transmission is less than 95%, less than 90% or less than 85%, between the intervals by a maximum of 30%, preferably by a maximum of 20%, particularly preferably by a maximum of 15% and preferably by a maximum of 10 % differs. An “at least essentially equivalent transmission of light” can include a transmission in the mentioned wavelength range for all pairs of arbitrarily selectable wavelengths in the mentioned wavelength range, in which in particular the transmission is less than 95%, less than 90% or less than 85%, differs between the wavelengths by a maximum of 40%, preferably by a maximum of 30%, particularly preferably by a maximum of 20% and preferably by a maximum of 10%. In addition, the term f f can include that at least a portion of the wavelength range mentioned exists in which the transmission is greater than 80%, greater than 85% or even greater than 90%. “Transmission” here means in particular a degree of transmission, i.e. a quotient of transmitted and incident intensity. The information relates in particular to those light intensities for which the transmission shows no or at least essentially no intensity dependence. In other words, the forwarding of light possible with sufficient efficiency over the entire wavelength range mentioned.

An “essentially equivalent image of light” can specifically be understood to mean that any pair can be selected in the specified wavelength range for all pairs Intervals in the wavelength range mentioned which have a width of at most 100 nm, at most 50 nm or even at most 10 nm and in which in particular a mean RMS point radius ("RMS" stands for "root mean square") is above the diffraction limit mean RMS point radius between the intervals differs by a maximum of a factor of 15, preferably a maximum of a factor of 10, particularly preferably a maximum of a factor of 5 and preferably a maximum of a factor of 3. A "substantially equivalent image of light" can include that an RMS point radius for all pairs of arbitrarily selectable wavelengths in the specified wavelength range, in which in particular the RMS point radius is above the diffraction limit, varies between the wavelengths by a maximum of a factor of 15, preferably by a maximum of a factor of 10, particularly preferably a maximum of a factor of 5 and preferably a maximum of a factor of 3. In addition, the term can include that at least a portion of the wavelength range mentioned exists in which the RMS point radius is below the diffraction limit. In other words, the imaging of light over the entire wavelength range mentioned is possible with sufficiently high focusing.

The term “for a given focusing” means in particular that light incidence into the lens arrangement is unchanged, i.e. occurs in the same way for different wavelengths. For example, if the lens arrangement is combined with an objective and/or eyepiece and is focused, changes The focusing for assessing the transmission and imaging of the light at different wavelengths is not the case. The focusing can include a predetermined and/or predeterminable focusing for a specific wavelength in the wavelength range mentioned, which is then maintained unchanged over the entire range mentioned.

The rod lenses and/or the correction elements can be designed as at least essentially cylindrical, preferably circular cylindrical, objects. A lateral surface of the rod lenses and/or the correction elements can be shaped like a cylinder jacket. Front and/or rear surfaces of the Rod lenses and/or the correction elements can deviate from the shape of a cylinder and, for example, be curved convexly or concavely.

The rod lenses are preferably elongated. The rod lenses can, for example, have a length that is at least a factor of 2, a factor of 3, a factor of 4, a factor of 5 or even a factor of 6 larger than a diameter of the rod lenses. The rod lenses can be designed differently or identically. In some embodiments, the lens arrangement may include several different types of rod lenses. These can differ in terms of their dimensions, their curvature, their breaking behavior, their coating, their material and/or other parameters.

In the context of this disclosure, the term “glass” can refer to any glass material. “Glass” should not be limited to silicate glass or silicon-based glass, although there are some embodiments of the first glass and/or the second glass can be silicate glass or silicon-based glass.

The Abbe number may be defined as within the scope of this disclosure

Vd = (n _d - 1 ) / (n _F - n _c ), where n , n _F and nc are the refractive indices of the material in question at the corresponding Fraunhofer lines. For example, the corresponding wavelengths for the Fraunhofer lines d, F and C are 587.56 nm, 486.13 nm and 656.27 nm.

Alternatively, the Abbe number can also be defined as within the scope of this disclosure

Ve = (n _e - 1 ) / (n _F ' - n _C '), where n _e , n _F > and nc' are the refractive indices of the material in question at the corresponding Fraunhofer lines. The Corresponding wavelengths for the Fraunhofer lines e, F 'and C' are, for example, 546.07 nm, 479.99 nm and 643.85 nm.

The relative partial dispersion mentioned can generally be the relative partial dispersion for two wavelengths x, y, which can be defined as follows:

Px,y = (n _x - n _y ) / (n _F - n _c ), where n _x and n _y denote the refractive indices at wavelengths x and y. In particular, the said relative partial dispersion of the first glass and the second glass can be P _g , _F , where g and F denote the corresponding Fraunhofer lines. The corresponding wavelengths for the Fraunhofer lines g and F and C' are, for example, 435.83 nm and 486.13 nm.

A glass with normal dispersion should in particular be understood to mean a glass for which the relevant relative partial dispersion and the Abbe number are linearly related, i.e. in particular glass that lies on a straight line in a Vd-P _x , _y diagram , which obeys the following relation:

P _x , _y = a _x , _y + b _x , _y • v _d , where a _x , _y and b _x , _y are dimensionless constants belonging to the partial dispersion determined by x and y . This can also be formulated analogously for v _e . For P _g , _F these constants are known to be a _g , _F = 0.6438 and b _g , _F = 0.001682. Such glass is also regularly referred to as “normal glass”. It is characterized by the fact that light is dispersed in the same way regardless of the spectral range.

Deviating from this, glass that differs from glass with normal dispersion can show different dispersion behavior in different spectral ranges, for example being more or less dispersive in the short-wave range than in the long-wave range. Such a glass is sometimes referred to as an abnormal dispersion glass. It should be understood that these terms are not to be equated with the sometimes used terms of normal dispersion and anomalous dispersion, which refer to the basic dispersion behavior of a material, namely having a refractive index that increases with frequency (“normal Dispersion") or which decreases with frequency ("anomalous dispersion"). Rather, the glass properties described herein may apply. different derivatives of the dispersion at different wavelengths, which can, however, have the same sign.

The relative partial dispersion of the first glass and the second glass deviates in the opposite way from normal dispersion glass in that the first glass in the Vd-Px, _y diagram is on one side of the line for normal dispersion glass and that second glass on a second side opposite the first side. This can apply analogously to a Vde-Px, _y diagram. A deviation parameter AP _x , _y can be defined as follows:

AP _x , _y = (n _x - n _y ) / (n _F - n _c ) - a _x , _y + b _x , _y • .

This can also be formulated analogously for v _e . A sign of the value of the deviation parameter AP _x , _y can be different for the first glass and the second glass.

The first lens can consist at least largely and/or completely of the first glass. The second lens can consist at least largely and/or completely of the second glass. “At least a majority” can mean at least 55%, preferably at least 65%, preferably at least 75%, particularly preferably at least 85% and very particularly preferably at least 95%, in particular with reference to a volume and/or a mass of an object .

Preferably, the first lens and the second lens are arranged directly behind one another and in particular in contact with one another and/or are formed integrally with one another, for example optically bonded and/or glued. The correction elements of the correction pair arrangement can be arranged symmetrically to one another with respect to the second plane of symmetry. The correction elements of the correction pair arrangement can be designed identically and, for example, can only be rotated relative to one another in order to produce symmetry. In other embodiments, the correction elements can be designed differently but symmetrically to one another.

A simple optical structure can be achieved in particular if the first plane of symmetry and the second plane of symmetry are identical. This means that optical modeling for adapting the lens arrangement can be carried out particularly easily. In other embodiments, the first plane of symmetry and the second plane of symmetry can be spaced apart from one another along the optical axis.

In some embodiments, the lens arrangement comprises at least one further correction pair arrangement, wherein the further correction pair arrangement comprises two further correction elements which are symmetrical to one another with respect to a third plane of symmetry which is perpendicular to the optical axis. This allows a high degree of image quality and image stability to be achieved. The further correction pair arrangement can be designed identically to the correction pair arrangement. Alternatively, the correction pair arrangements can differ, for example with regard to the correction elements used and/or their relative position and/or orientation.

A high degree of flexibility with regard to the design of the lens arrangement and the associated versatile options for achieving high imaging quality can be achieved in particular if the second plane of symmetry and the third plane of symmetry are different from the first plane of symmetry. The second plane of symmetry and the third plane of symmetry can be identical. Alternatively, it can be provided that the second plane of symmetry is different from the third plane of symmetry. The planes of symmetry can be spaced apart along the optical axis. In further embodiments, the first plane of symmetry and the third plane of symmetry can be identical to one another but different from the second plane of symmetry.

Within the scope of this disclosure, different symmetry planes can be spaced apart from one another by at least 1 cm, by at least 2 cm, by at least 5 cm, by at least 10 cm or even by at least 20 cm along the optical axis.

Furthermore, it can be provided that the correction elements each include at least one third lens. In some

According to embodiments, the third lens is made from the first glass and/or from the second glass. In other

In embodiments, the third lens can also be made from a third glass that is different from the first glass and/or second glass. The third glass can in particular be different from a glass that shows normal dispersion in the sense of this disclosure. The third lens can consist at least largely and/or completely of the first glass, the second glass or the third glass. The second lens can be arranged between the first lens and the third lens. Preferably, the first lens, the second lens and the third lens are arranged directly one behind the other and in particular in contact with one another and/or are formed integrally with one another, for example optically bonded and/or glued.

Assembly effort and/or the number of components can be reduced in particular if the correction elements are each integrally formed with a rod lens. Generally speaking, at least one of the correction elements can be formed integrally with at least one of the rod lenses. “Integral” includes both one-piece and one-piece. At least one lens of the correction element in question can be formed integrally with the rod lens in question. Preferably, all lenses of the correction element in question are formed integrally with the rod lens in question. For example, in these cases the The first lens can be arranged directly next to the rod lens and / or optically bonded and / or glued to it. The arrangement can also be reversed, so that the second lens is arranged immediately next to the rod lens. The second lens can then additionally be arranged directly next to the first lens and/or optically bonded and/or glued to it. In some embodiments, the correction element can be attached to a planar surface of the rod lens and/or bonded and/or glued thereto.

Furthermore, the correction pair arrangement can comprise at least one aperture which is arranged in the area of the second plane of symmetry. As a result, an aperture of the lens arrangement can be appropriately attached. In some variants, the second plane of symmetry intersects the aperture. The aperture in particular has a smaller diameter than the rod lenses and/or the correction elements and/or the lenses of the correction elements. Information regarding A symmetry of the lens arrangement can refer in particular to the components of the lens arrangement without the aperture, i.e. apart from the aperture. In other words, the lens arrangement can be symmetrical without the aperture, but the aperture can be arranged off-center, for example. In principle, several apertures can also be provided. These can be arranged symmetrically to one another with respect to one or any or all of the planes of symmetry mentioned and/or each can be designed symmetrically thereto.

Depending on the design of the lens arrangement or of the optical system that defines the rod lenses and the correction elements, at least one of the first lenses and/or at least one of the second lenses can be a convex lens. Alternatively or additionally, at least one of the first lenses and/or at least one of the second lenses can be a concave lens. The second lenses can be designed identically. The first lenses can be designed identically.

High image quality over a large spectral range can be achieved in particular if the lens arrangement enables optical images in the range from 400 nm to 1000 nm, which have an RMS point radius of at most 40 pm, preferably at most 35 pm and preferably at most 30 pm. This can mean in particular that for any arbitrarily chosen interval in this range with a width of at most 50 nm, preferably at most 40 nm, particularly preferably at most 30 nm and preferably at most 20 nm, a mean RMS point radius is at most 40 pm, preferably at most 35 pm and preferably at most 30 gm. This can also mean that for any wavelength an RMS point radius is at most 40 gm, preferably at most 35 gm and preferably at most 30 gm.

In some embodiments, the lens arrangement can enable diffraction-limited optical images in the range from 480 nm to 1000 nm. In other words, the lens arrangement can be designed in such a way that diffraction-limited optical imaging is possible for any wavelength in the range from 480 nm to 1000 nm. A diffraction-limited optical image is characterized in particular by the fact that a calculated RMS point radius is less than or equal to a value that is defined by the diffraction limit.

The lens arrangement can have a maximum RMS point radius of at most 8 pm, preferably at most 6 pm and preferably at most 4 pm, in particular in the range from 480 nm to 1000 nm. In other words, for any wavelength, in particular in the range from 480 nm to 1000 nm, an RMS point radius can have a maximum of 8 pm, preferably a maximum of 6 pm and preferably a maximum of 4 pm.

The inventors have also recognized that conventional lens arrangements sometimes transmit well in the visible range, but show significantly poorer transmission in the near-infrared range. This significantly limits the usability of such conventional lens arrangements, particularly for multispectral applications and hyperspectral applications in which imaging is also intended in the near-infrared range. High-quality images in a wide spectral range can be made possible in particular if the rod lenses and the correction elements have anti-reflective surfaces that work in the visible range and in the near-infrared range. In other words, the anti-reflective surfaces can be designed in such a way that, in contrast to anti-reflective surfaces, which only Optimize the transmission in the visible range, although a slightly lower transmission may be accepted under certain circumstances, but the transmission remains at a high level beyond the visible range instead of decreasing rapidly. Anti-reflective surfaces can include a coating of the relevant optical elements, for example an anti-reflective coating. Alternatively or additionally, a surface of the optical elements in question can itself be treated, for example roughened microscopically and/or nanoscopically.

In particular, it can be provided that the anti-reflective surfaces in the range from 400 nm to 1000 nm each have an average reflection of at most 2%, preferably at most

1% and preferably at most 0.6%. Alternatively or additionally, it can be provided that the anti-reflective surfaces in the range from 400 nm to 1000 nm each have a maximum reflection of at most 3%, preferably at most

2% and preferably a maximum of 1%.

The anti-reflective surfaces mentioned can be present on at least one surface of at least one optical element of the lens arrangement, for example on at least one rod lens and/or on at least one correction element, for example on at least one of the lenses. Preferably, at least a majority of the surfaces present are provided with anti-reflective surfaces, preferably all of them.

The lens arrangement can have an average transmission of at least 70%, preferably at least 80% and particularly preferably at least 85% in the range from 400 nm to 1000 nm. Alternatively or additionally, the lens arrangement can have a minimum transmission of at least 60%, preferably at least 70% and particularly preferably at least 80% in the range from 400 nm to 1000 nm. This makes it possible to transmit light over a broad spectrum through the entire lens arrangement, whereby light can be transmitted efficiently both in the visible range and in the near-infrared range. The invention further relates to an endoscope with an endoscope device according to the invention and/or with a correction pair arrangement according to the invention. In some embodiments, the endoscope is designed to be insertable into a cavity for inspection and/or observation, for example into an artificial and/or natural cavity, such as into the interior of a body, into a body organ, into tissue or the like. The endoscope can also be designed to be insertable into a housing, a casing, a shaft, a pipe or another, in particular artificial, structure for inspection and/or observation.

Furthermore, the invention relates to an imaging system, in particular a medical imaging system. The imaging system includes an illumination device configured to provide illuminating light in both the visible and near-infrared regions. Furthermore, the imaging system comprises an endoscope device according to the invention and/or an endoscope according to the invention. The imaging system also includes an imaging device with an image capture unit that is set up to capture multispectral and/or hyperspectral image data. The image capture unit can include an image capture sensor system.

The imaging system can be multimodal. In particular, the imaging system can be set up to optionally record white light images and/or multispectral images and/or fluorescence images and/or hyperspectral images.

The image capture sensor system can be set up to detect light in both the visible range and the near-infrared range. In some embodiments, a smallest detectable wavelength can be at most 500 nm, at most 450 nm or even at most 400 nm. In some embodiments, a largest detectable wavelength can be at least 800 nm, at least 900 nm or even at least 1000 nm. The image capture sensor system can, for example, include at least one white light image sensor and at least one near-infrared image sensor. In some embodiments, the imaging device includes a white light camera and/or sensors for white light image capture. The imaging device can be set up for white light imaging. The anatomy images can be recorded using the white light camera and/or the sensor system for white light image capture.

The image capture unit can have a filter unit with optical observation filters. The filter unit can define several fluorescence modes, which are defined by different observation filters. For example, different edge filters can be used, which absorb/block the respective spectrum of the associated lighting element used for excitation and at least essentially only transmit fluorescent light. The observation filter, which blocks light in the first spectral range, is then part of the filter unit. In some embodiments, the observation filters can also be switchable between a multispectral mode and a fluorescence mode.

The imaging device and in particular an optics and/or the image capture sensor system can/can be set up for multispectral and/or hyperspectral imaging, in particular to capture and/or generate multispectral and/or hyperspectral image data. Multispectral imaging or Multispectral image data can refer in particular to such imaging in which at least two, in particular at least three, and in some cases at least five spectral bands can be detected and/or are detected independently of one another. Hyperspectral imaging or Hyperspectral image data can refer in particular to such imaging in which at least 20, at least 50 or even at least 100 spectral bands can be detected and/or are detected independently of one another. The imaging device can work according to the pushbroom method and/or according to the whiskbroom method and/or according to the staring method and/or according to a snapshot principle.

For some applications it may be advantageous to be able to use a large spectral resolution. It then presents itself hyperspectral imaging. This can be combined with white light imaging. This makes observation in real time via a white light image possible, even if the acquisition of spectrally resolved image data only takes place essentially in real time, i.e., for example, several seconds are required to create a spectrally resolved image. For some applications it may be advantageous to generate spectral image data in real time. This includes, for example, generating a spectrally resolved image in less than a second or even several times per second. It may be useful to use multispectral imaging. One if necessary. A lower spectral resolution is then offset by a higher refresh rate. Depending on the application, it may be sufficient to consider only a few different spectral ranges and/or wavelengths, for example two or three or four or generally less than ten. In this case, additional white light imaging can optionally be dispensed with. Spectrally resolved image data that is obtained in real time or Delivering several images per second can also be used for surveillance purposes, whereby an image does not necessarily have to be created for a user to be played back, but the image data can also be processed in the background.

The image capture sensor system in particular has at least one image sensor. Furthermore, the image capture sensor system can also have at least two and preferably several image sensors, which can be arranged one behind the other. Furthermore, the two and preferably several image capture sensors can have spectral detection sensitivities that are designed differently from one another, so that, for example, a first sensor in a red spectral range, a second sensor in a blue spectral range and a third sensor in a green spectral range are particularly sensitive or is comparatively more sensitive than the other sensors. The image sensor can be designed as a CCD sensor and/or a CMOS sensor. The image capture unit is designed in particular to generate at least two-dimensional spatial image data. The image capture unit can be spatially resolving in that it provides a resolution of at least 100 pixels, preferably of at least 200 pixels, preferably of at least 300 pixels and advantageously of at least 400 pixels in at least two different spatial directions. The image data is preferably at least three-dimensional, with at least two dimensions being spatial dimensions and/or with at least one dimension being a spectral dimension. Several spatially resolved images of the image area can be obtained from the image data, each of which is assigned to different spectral bands. The spatial and spectral information of the image data can be created in such a way that an associated spectrum can be obtained for several spatial image points.

In some embodiments, the image capture unit is set up to generate continuously updated image data. The image capture unit can, for example, be set up to generate the image data essentially in real time, which includes, for example, generation of updated image data at least as 30 seconds, in some cases at least as 20 seconds and in some cases even at least every 10 seconds or at least every 5 seconds . The image capture unit is preferably set up to generate at least the anatomy images and the fluorescence images as well as the representation based on them in real time, for example with a frame rate of at least 5 fps, at least 10 fps, at least 20 fps or even at least 30 fps.

The lighting device can be designed to be multimodal and include a plurality of lighting elements that can be activated independently of one another and are designed to emit light according to different emission spectra in order to provide the illuminating light.

The lighting device can include an optical interface for the optical connection of the endoscope. The lighting unit can be set up to To deliver illumination light to the optical interface. The lighting unit can be designed to be multimodal and include a plurality of lighting elements that can be activated independently of one another and are designed to emit light according to different emission spectra in order to provide the illuminating light. The lighting unit can be operable in at least one multispectral mode, in which a first group of the lighting elements is activated at least temporarily and in which the lighting unit supplies illuminating light for multispectral imaging. Furthermore, the lighting unit can be operable in at least one fluorescence mode, in which a second group of the lighting elements is activated at least temporarily and in which the lighting unit supplies illuminating light for fluorescence imaging. The lighting elements can include at least one lighting element that is included in both the first group and the second group.

In addition, a method for generating illumination light for an imaging device by means of an illumination device can be provided. The lighting device comprises an optical interface for the optical connection of the endoscope and a lighting unit that is set up to deliver illuminating light to the optical interface, the lighting unit comprising a plurality of lighting elements that can be activated independently of one another and that are set up to emit light according to different emission spectra emit to provide the illumination light. The method includes the step of at least temporarily activating a first group of the luminous elements to provide illuminating light for multispectral imaging and the step of at least temporarily activating a second group of the luminous elements to provide illuminating light for fluorescence imaging. At least one of the lighting elements is activated at least temporarily both when the first group of lighting elements is activated at least temporarily and when the second group of lighting elements is activated at least temporarily. The optical interface can be either detachable or connectable. In addition, the optical interface can be combined with a mechanical interface, so that an optical connection is established automatically, for example, when the endoscope is mechanically coupled.

The lighting elements can include single-color LEDs (light-emitting diodes) and/or laser diodes. Furthermore, at least one of the lighting elements can be a white light LED or another white light source. In some embodiments, the lighting unit comprises at least one blue lighting element, at least one red lighting element, at least one dark red lighting element and at least one near-IR lighting element (near-infrared lighting element), in particular LEDs or laser diodes. In addition, the lighting unit can include at least one white light LED or another white light source.

The first group can include at least two lighting elements that emit spectrally differently. A high degree of efficiency in multispectral imaging can be achieved if the multispectral mode includes different states in which a specific luminous element or a certain type of lighting element is activated at least temporarily. This allows targeted illumination in a specific spectral range, allowing different spectral images to be captured. Different lighting elements, which are activated in different states, can serve as different support points for multispectral imaging. At least one of these support points can be selected in such a way that it is adapted to characteristic points of absorption spectra of physiologically relevant components, for example to an isosbestic point of the hemoglobin oxygenation curve. Multispectral imaging may additionally include the use of suitable observation filters.

Furthermore, the second group can include at least two lighting elements that emit spectrally differently. The fluorescence mode can include different sub-modes and/or states, each in which a specific luminous element or . a certain type of lighting element is activated at least temporarily. This allows targeted excitation in a specific spectral range, so that fluorescence imaging can be carried out for a specifically selected dye. In other words, the at least one luminous element that is contained both in the first group and in the second group can be used both for the multispectral mode and for the fluorescence mode.

In some embodiments, the first group includes only some but not all of the lighting elements. Alternatively or additionally, in some embodiments, the second group only includes some but not all of the lighting elements. In the multispectral mode, in particular, only lighting elements of the first group are activated at least temporarily, whereas lighting elements that do not belong to the first group are deactivated. In the fluorescence mode, in particular, only lighting elements of the second group are activated at least temporarily, whereas lighting elements that do not belong to the second group are deactivated. In general, it is understood that the lighting elements can include different types of lighting elements and that of the different types of lighting elements, in particular, exactly one lighting element can be present. It is understood that mixed operating modes can also occur according to the invention, in which the modes mentioned are used sequentially. For example, multispectral imaging and fluorescence imaging can be performed sequentially.

Synergy with regard to the use of a lighting element for different modes and associated efficiency gains can be achieved in particular if at least one lighting element, which is included in both the first group and the second group, emits light in the red spectral range, in particular in a spectral range between 600 nm and 680 nm, for example between 610 nm and 650 nm or between 620 and 660 nm or between 630 and 670 nm. The spectral range can be narrow band and include the wavelength 660 nm. “Narrowband” can have a spectral width of at most 80 nm, in particular at most 40 nm or even include at most 20 nm. This at least one lighting element can be set up to excite dyes that absorb in the red spectral range and to make a contribution to the illumination in the red spectral range for multispectral imaging.

In some embodiments, the illumination unit can be operable in at least one white light mode, in which the illumination unit supplies illumination light for white light imaging. The illuminating light for white light imaging can be broadband white light. Alternatively, the illuminating light for white light imaging may comprise a plurality of narrow wavelength bands that are separated from one another, for example a blue, a red and a far-red band. "Dark red" is to be understood in the sense of "long wavelength as red" and refers to the spectral position, not the light intensity. The illuminating light for white light imaging can be mixed from light from different lighting elements.

In the white light mode, a third group of the lighting elements can be activated at least temporarily to provide the illuminating light for the white light imaging. The lighting elements can include at least one lighting element that is contained both in the first group and/or in the second group and in the third group. In some cases, the third group may include only some but not all of the lighting elements. In the white light mode, in particular, only lighting elements of the third group are activated at least temporarily, whereas lighting elements that do not belong to the third group are deactivated. In other words, the lighting unit can include lighting elements that serve one, two or all three of the lighting modes mentioned. This means that several lighting elements can be used multiple times.

At least one luminous element, which is included both in the first group and/or in the second group and in the third group, can emit light in the red spectral range, in particular in a spectral range between 600 nm and 680 nm, for example between 610 nm and 650 nm or between 620 and 660 nm or between 630 and 670 nm. The advantages of The common use of lighting elements is particularly important when at least one red lighting element can be used for all three modes.

At least one luminous element, which is contained both in the first group and/or in the second group and in the third group, can emit light in the blue spectral range, in particular in a spectral range between 440 and 480 nm. At least one blue luminous element can expediently be used both in the fluorescence mode and in the white light mode.

In general terms, as mentioned, the luminous elements can comprise at least one, in particular blue, luminous element that emits light in a spectral range between 440 and 480 nm. In addition, as mentioned, the lighting elements can comprise at least one, in particular red, lighting element that emits light in a spectral range between 600 and 680 nm, for example between 610 nm and 650 nm or between 620 and 660 nm or between 630 and 670 nm. Alternatively or additionally, the lighting elements can comprise at least one, in particular dark red, lighting element that emits light in a spectral range between 750 and 790 nm. Alternatively or additionally, lighting elements can comprise at least one, in particular near-IR emitting, lighting element that emits light in a spectral range between 920 and 960 nm. In addition, the lighting elements can include a white light lighting element. A compact and versatile lighting unit can be provided in particular if at least one of each of the lighting element types mentioned is present. For example, in the fluorescence mode, the blue and the red, in the case of suitable dyes, can be used if necessary. The dark red light element can also be used. In multispectral mode, the dark red and near-IR emitting lighting elements can be used. The white light luminous element can be used in white light mode. In white light mode, this can be supplemented by the blue light element and, if necessary. also the red lighting element. This allows wavelength ranges to be supplemented using colored lighting elements in which the white light lighting element, for example due to its Construction but in particular due to filters and optical elements of the lighting unit, delivers a reduced intensity. In addition, the colored lighting elements can be used to set a color temperature in white light imaging.

In some embodiments, the second group includes a single lighting element and/or a single type of lighting elements. For example, a white light luminous element, a red luminous element and an IR-emitting luminous element can be provided, with respect to. possible spectral ranges, reference is made in particular to the above values. The first group can then include, for example, the red and the IR-emitting lighting element. The second group can include the IR-emitting lighting element, in particular as a single lighting element or as the only type of lighting element.

A favorable arrangement of lighting elements is made possible in particular if the lighting unit comprises at least one crossed beam splitter, by means of which light can be deflected from opposite input sides to an output side, with at least one of the lighting elements being arranged on the opposite input sides of the crossed beam splitter. In some embodiments, two or more crossed beam splitters can be provided, which are optically arranged one behind the other. The at least one crossed beam splitter can comprise two beam splitter elements, the transmittance of which is adapted to the respectively assigned lighting element. The beam splitter elements in particular each include a notch filter, so that they each reflect in a narrow spectral band, but otherwise transmit. The spectral position and/or width of the corresponding notch can be adapted to the spectral range of the respectively assigned lighting element, so that its light is deflected, but light from other lighting elements is at least largely transmitted.

In some embodiments, the lighting elements can have at least four narrow-band emitting individual color lighting elements, each with different ones Spectral ranges and at least one broadband emitting white light luminous element. In this regard, reference is also made to the above statements regarding the colored lighting elements.

A large range of functions in combination with a compact design and the utilization of synergy effects when using lighting elements can be achieved in particular if the lighting unit can be operated in at least one hyperspectral mode, in which several lighting elements are activated, the emission spectra of which together cover at least a spectral range of Covering 450 nm to 850 nm, and in which the illumination unit provides illumination light for hyperspectral imaging. This can in particular be all of the lighting elements.

It is understood that, particularly in the case of using laser diodes, suitable polarization filters can be used for the optical filters mentioned herein. Furthermore, particularly in the case of using laser diodes, at least one crossed beam splitter can be used, the beam splitter elements of which are provided with polarization filters. Selective transmittance can then be achieved by combining different polarizations.

The devices and systems according to the invention as well as the methods according to the invention should not be limited to the application and embodiment described above. In particular, these can have a number of individual elements, components and units as well as process steps that deviate from the number of individual elements, components and units as well as process steps mentioned here in order to fulfill a functionality described herein. In addition, in the value ranges specified in this disclosure, values that lie within the stated limits should also be considered disclosed and can be used in any way.

It is particularly pointed out that all features and properties described in relation to a device, but also procedures, can be transferred to processes and can be used in the sense of the invention and are considered disclosed. The same applies in the opposite direction. It means that Structural features that are mentioned in relation to methods, i.e. features corresponding to the device, can also be taken into account, claimed and also counted as part of the disclosure within the scope of the device claims.

The present invention is described below by way of example using the attached figures. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will also expediently consider the features individually and use them in combination within the scope of the claims.

If there is more than one copy of a certain object, it may be necessary. only one of them is given a reference symbol in the figures and in the description. The description of this instance can be transferred accordingly to the other instances of the object. Are objects particularly using number words, such as first, second, third object etc. named, these serve to name and/or assign objects. Accordingly, for example, a first object and a third object, but not a second object, can be included. However, a number and/or a sequence of objects could also be derived from number words.

Show it :

Fig. 1 is a schematic representation of an imaging system with an illumination device, an endoscope with an endoscope device and an image capture device;

Fig. 2 is a schematic representation of a lens arrangement of an endoscope device according to the prior art;

Fig. 3 is a schematic representation of images of a line pattern 12 performed with the lens arrangement according to the prior art; Fig. 4 is a diagram regarding the wavelength dependence of an RMS spot radius of the lens arrangement according to the prior art;

Fig. 5 a schematic representation of a first endoscope device;

Fig. 6 is a schematic representation of a correction pair arrangement of the first endoscope device;

Fig. 7 is a diagram illustrating the selection of glass for the correction pair assembly;

Fig. 8 is a schematic representation of a second endoscope device;

Fig. 9 a schematic representation of a correction pair arrangement of the second endoscope device

Fig. 10 is a schematic representation of a third endoscope device;

Fig. 11 is a schematic representation of a correction pair arrangement of the third endoscope device;

Fig. 12 is a schematic representation of images of a line pattern 12 performed with the first endoscope device, the second endoscope device or the third endoscope device;

Fig. 13 is a diagram regarding the wavelength dependence of an RMS spot radius of the first endoscope device, the second endoscope device or the third endoscope device;

Fig. 14 is a schematic representation of a lens arrangement with anti-reflective surfaces;

Fig. 15 is a schematic diagram illustrating different reflectivity curves; Fig. 16 is a schematic diagram illustrating different transmission curves;

Fig. 17 is a schematic representation of the lighting device 150; and

Fig. 18 schematic transmission curves of beam splitter elements of the lighting device.

Fig. 1 shows a schematic representation of an imaging system 148. The imaging system 148 is an endoscopic imaging system. The imaging system 148 may be a medical imaging system. In the present case, the imaging system 148 is a multispectral and/or hyperspectral endoscopic imaging system.

The imaging system 148 includes an illumination device 150, an endoscope device 110 and an imaging device 152 with an image capture unit 154. The image capture unit 154 is set up to capture multispectral and/or hyperspectral image data.

The image capture unit 154 includes suitable image capture sensor system 158 for this purpose, which is only shown as an example.

The image capture sensor system 158 may include a CMOS or CCD sensor, not shown. The image capture sensor system 158 and if necessary. associated optical elements can be arranged in a pushbroom arrangement. In other

In embodiments, a whiskbroom arrangement, a staring arrangement and/or a snapshot arrangement is used. Regarding different methods of hyperspectral imaging and the components required for this, please refer to the specialist article "Review of spectral imaging technology in biomedical engineering: achievements and challenges" by Quingli Li et al. Published in Journal of Biomedical Optics 18 (10), 100901, October 2013, as well as the specialist article "Medical hyperspectral imaging: a review" by Guolan Lu and Baowei Fei, published in Journal of Biomedical Optics 19 (1), 010901, January 2014, referenced.

In other embodiments, as mentioned, the image capture unit 154 can also be multispectral. Several spectral ranges can be viewed, for example, through filters that can be selectively inserted into an object light beam path and/or through sequential illumination with different wavelengths.

The endoscope device 110 is part of an endoscope 146. The endoscope 146 may include parts of the image capture unit 154. The endoscope device 110 includes a shaft 160. The shaft 160 is configured to accommodate a lens assembly configured to guide imaging light from a distal end 162 of the endoscope device 110 and/or the shaft 160 to a proximal end 164 of the endoscope device 110 and/or the shaft 160. This will be discussed further below. The shaft 160 can be rigid. In particular, the endoscope 146 is a rigid endoscope and/or the endoscope device 110 is an endoscope device for a rigid endoscope.

Fig. 2 shows a schematic representation of a lens arrangement 212 of an endoscope device 210 according to the prior art. The endoscope device 212 includes an eyepiece 216 and an objective 218. The lens arrangement 212 couples the eyepiece 216 and the objective 218 in a known manner. Light collected by the objective 218 may be transmitted to the eyepiece 216 through the lens assembly 212 . This allows an image to be created.

The lens arrangement 212 includes a plurality of rod lenses 222. The lens arrangement 212 is primarily intended to transmit and image light in the visible range, for example in a range from 450 nm to 750 nm.

Fig. 3 shows a schematic representation of images of a line pattern performed with the lens arrangement 212 according to the prior art. Fig. 4 shows a diagram regarding the Wavelength dependence of an RMS point radius of the lens arrangement 212. As can be seen, the RMS spot radius is small in a medium wavelength range and is even below the dashed line in Fig. 4 marked diffraction limit. If the line pattern is imaged, the result is in the middle wavelength range, in this case for example for light with wavelengths between 486 nm and 656 nm, which is shown in Fig. 3 picture shown in the middle. A sharp image of the line pattern can be obtained here because the lens arrangement 212 images well in this area. However, due to lens errors, in particular due to chromatic aberration, an equally sharp image cannot be obtained for smaller and larger wavelengths at the same time. In these areas the RMS point radius is significantly larger, which leads to a blurry image. This is shown in Fig. 3 shown on the left as an example for the wavelength range from 400 nm to 500 nm, on the right as an example for the wavelength range from 800 nm to 1000 nm. Particularly in the near-infrared range, i.e. in the latter range, the imaging quality is rather low, so that geometric features cannot be depicted in detail.

The conventional endoscope device 210 can therefore primarily be used in the visible range. For example, if it is used for white light imaging, which is roughly a combination of the cases in Fig. 3 on the left and in the middle corresponds, an image quality may be sufficient. However, if imaging is also intended in the near-infrared, the quality may not be sufficient to obtain meaningful image data that could be used, for example, to assess the anatomical properties of a patient's examined anatomy.

Fig. 5 shows a schematic representation of a first endoscope device 110 according to the present disclosure. The first endoscope device 110 can be used in both the visible and near-infrared regions. The endoscope device 110 includes a lens assembly 112, an eyepiece 116 and an objective 118. These are present in the one shown in Fig. 1 shown shaft 160 arranged. The lens arrangement 112 optically couples the eyepiece 116 and the objective 118. Light can therefore be transmitted and imaged substantially equally through the lens arrangement 112 at least in a range between 480 nm and 1000 nm, preferably in a range between 400 nm and 1000 nm.

The lens arrangement 112 includes six rod lenses 122. Furthermore, the lens arrangement 112 includes two correction elements 124. The lens assembly 112 defines an optical axis 114. The rod lenses 122 and the correction elements 124 are arranged coaxially with respect to the optical axis 114. In the case shown, the rod lenses 122 and the correction elements 124 each have a circular cross section, the center of which lies on the optical axis 114.

The lens arrangement 112 is symmetrical with respect to a first plane of symmetry 120. The first plane of symmetry 120 is perpendicular to the optical axis 114.

The two correction elements 124 are part of a correction pair arrangement 134 or form these. The two correction elements 124 of the correction pair arrangement 134 are with respect to. a second plane of symmetry 136 symmetrical to one another. In this embodiment, the second plane of symmetry 136 corresponds to the first plane of symmetry.

The correction pair arrangement 134 is shown in FIG. 6 shown in more detail. Each of the correction elements 124 of the correction pair assembly 134 includes a first lens 130, a second lens 132 and a third lens 142. These form a lens triplet. The first lens 130, the second lens 132 and the third lens 142 are formed integrally, for example by gluing and/or optical bonding. Together they form a lens system 128.

The first lens 130 is made of a first glass and the second lens 132 is made of a second glass. The first glass and the second glass are selected to deviate in opposite ways from normal dispersion glass. This is shown in Fig. 7 shown schematically. Fig. 7 shows a diagram in which the relative partial dispersion P _g ,F is plotted against the Abbe number d. The solid line defines the points on which glass with normal dispersion lies. In this regard, reference is made in particular to the above statements on glass with normal and abnormal dispersion. The first glass and the second glass are located in the diagram at positions indicated by the two black dots in Fig. 7 are shown. The first glass lies to the right of the line at a large Abbe number and deviates in a first direction from glass with normal dispersion. The second glass lies to the left of the line at a small Abbe number and deviates in a second direction opposite to the first direction from glass with normal dispersion.

The first glass, for example, has an Abbe number d of 63.66, a refractive index m of 1.61800 and a dispersion nF - nc of 0.009758. The second glass has, for example, an Abbe number Vd of 42.41, a refractive index m of 1.63775 and a dispersion nF - nc of 0.015038. The two glasses are therefore deliberately chosen to be different and deliberately such that their deviation from normal dispersion is opposite. This allows the lens arrangement 112 to provide high-quality images over a wide spectral range.

In the present embodiment, the third lens 142 is also made from the first glass.

The first lens 130 is a concave lens. The second lens 132 is a convex lens. The third lens 142 is a concave lens. By way of example, the first lens 130 has a radius of curvature of -6 mm. Furthermore, by way of example, the second lens 132 has a radius of curvature of 6 mm. In addition, by way of example, the third lens 142 has a radius of curvature of 90 mm.

The correction pair arrangement 134 has an aperture 144 which is arranged in the area of the second plane of symmetry 136 . The aperture 144 has a smaller diameter than the rod lenses 112 and the correction elements 124. 8 shows a schematic representation of a second endoscope device 110′ according to the present disclosure. For better differentiation, the reference numbers in this embodiment are provided with apostrophes. Unless otherwise described, reference can generally be made to the statements above with regard to the existing components. The second endoscope device 110' can be used in both the visible and near-infrared regions. The second endoscope device 110″ includes a lens assembly 112′, an eyepiece 116′ and an objective lens 118′. In the present case, these are arranged in the shaft 160 shown in FIG. The lens arrangement 112' optically couples the eyepiece 116' and the objective 118'. Light can therefore be transmitted and imaged substantially equally through the lens arrangement 112' at least in a range between 480 nm and 1000 nm, preferably in a range between 400 nm and 1000 nm.

The lens arrangement 112' includes ten rod lenses 122'. Furthermore, the lens arrangement 112' includes six correction elements 124'. The lens assembly 112' defines an optical axis 114'. The rod lenses 122' and the correction elements 124' are arranged coaxially with respect to the optical axis 114'. In the case shown, the rod lenses 122' and the correction elements 124' each have a circular cross section, the center of which lies on the optical axis 114'.

The lens arrangement 112' is symmetrical with respect to a first plane of symmetry 120'. The first plane of symmetry 120' is perpendicular to the optical axis 114'.

Two of the correction elements 124 'are part of or form a correction pair arrangement 134'. The two correction elements 124' of the correction pair arrangement 134' are symmetrical to one another with respect to a second plane of symmetry 136'. The second plane of symmetry 136 'corresponds to the first plane of symmetry in this embodiment.

Each two further correction elements 124' form two further correction pair arrangements 138', 168'. These are each symmetrical to one another with respect to a third plane of symmetry 140' and a fourth plane of symmetry 166'. The third plane of symmetry 140' and the fourth plane of symmetry 166' are each perpendicular to the optical axis 114'.

The two further correction pair arrangements 138'', 168'' are arranged and/or designed symmetrically with respect to the first plane of symmetry 120''. Furthermore, as mentioned, the correction pair arrangement 134'' is symmetrical with respect to the first plane of symmetry 120''. The six correction elements 124'' are thus arranged symmetrically in this embodiment with respect to the first plane of symmetry 120''.

The correction pair arrangement 134' is shown in more detail in FIG. 9. Each of the correction elements 124' of the correction pair assembly 134' includes a first lens 130' and a second lens 132'. The first lens 130' and the second lens 132' are formed integrally, for example by gluing and/or optical bonding. Together they form a lens system 128'.

The first lens 130' is made of a first glass and the second lens 132' is made of a second glass. The first glass and the second glass are selected to deviate in opposite ways from normal dispersion glass. In this regard, reference is made again to FIG. 7 for illustration purposes.

For example, the first glass has an Abbe number d of 42.41, a refractive index m of 1.63775 and a dispersion nF - nc of 0.015038. The second glass, for example, has an Abbe number V of 63.33, a refractive index m of 1.61800 and a dispersion nF - nc of 0.009758. The two glasses are therefore deliberately chosen to be different and deliberately such that their deviation from normal dispersion is opposite. This allows the lens arrangement 112' to provide high-quality images over a wide spectral range.

The first lens 130' is a convex lens. The second lens 132' is a concave lens. By way of example, the first lens 130' has a curvature radius of 12 mm. Furthermore, by way of example, the second lens 132' has a radius of curvature of -4.8 mm.

The correction pair arrangement 134' has an aperture 144' which is arranged in the area of the second plane of symmetry 136'. The aperture 144 'has a smaller diameter than the rod lenses 112 and the correction elements 124.

In the present embodiment, the correction elements 124' are formed integrally with a rod lens 122' each. They are, for example, glued and/or optically bonded to an end surface, in particular a planar one, of the rod lens 122' in question.

A further lens 172', which is part of the rod lens 122', is arranged on a side opposite the respective correction element 124'. This is glued and/or optically bonded to a base body of the rod lens 122'. In the present case, the base body of the rod lens 122 'is made of a glass that has an Abbe number Vd of 50.19 and a refractive index m of 1.62658. The base body of the rod lens 122' has planar end surfaces. The further lens 172 ' is made of a glass that has an Abbe number Vd of 49.34, as well as a refractive index m of 1.74320 and a dispersion nF - m of 0.015063. The further lens 172' is a concave lens and has, for example, a radius of curvature of 13.7 mm.

10 shows a schematic representation of a third endoscope device 110″ according to the present disclosure. To make them easier to distinguish, the reference numbers in this embodiment are provided with two apostrophes. Unless otherwise described, reference can generally be made to the statements above with regard to the existing components. The third endoscope device 110″ can be used in both the visible and near-infrared regions. The third endoscope device 110'' includes a lens assembly 112'', an eyepiece 116'' and an objective lens 118''. In the present case, these are arranged in the shaft 160 shown in FIG. The Lens arrangement 112'' optically couples the eyepiece 116'' and the objective 118''. Light can therefore be transmitted and imaged substantially equivalently through the lens arrangement 112″ at least in a range between 480 nm and 1000 nm, preferably in a range between 400 nm and 1000 nm.

The lens arrangement 112'' includes six rod lenses 122''. Furthermore, the lens arrangement 112'' includes four correction elements 124''. The lens assembly 112'' defines an optical axis 114''. The rod lenses 122'' and the correction elements 124'' are arranged coaxially with respect to the optical axis 114''. In the case shown, the rod lenses 122'' and the correction elements 124'' each have a circular cross section, the center of which lies on the optical axis 114''.

The lens arrangement 112'' is symmetrical with respect to a first plane of symmetry 120''. The first plane of symmetry 120'' is perpendicular to the optical axis 114''.

Two of the correction elements 124'' are part of or form a correction pair arrangement 134''. The two correction elements 124'' of the correction pair arrangement 134'' are symmetrical to one another with respect to a second plane of symmetry 136''. The second plane of symmetry 136'' is different from the first plane of symmetry 120''. The second plane of symmetry 136'' is perpendicular to the optical axis 114''.

Two more of the correction elements 124'' are part of or form another correction pair arrangement 138''. The two correction elements 124'' of the further correction pair arrangement 138'' are symmetrical to one another with respect to a third plane of symmetry 140''. The third plane of symmetry 140'' is different from the first plane of symmetry 120'' and from the second plane of symmetry 136''. The third plane of symmetry 140'' is perpendicular to the optical axis 114''.

The correction pair arrangement 134'' and the further correction pair arrangement 138'' are arranged symmetrically with respect to the first plane of symmetry 120'' and/or educated. In this embodiment it can be provided that there is no correction pair arrangement in the area of the first symmetry plane 120''.

The correction pair arrangement 134'' is shown in more detail in FIG. 11. Each of the correction elements 124'' of the correction pair assembly 134'' includes a first lens 130'', a second lens 132'' and a third lens 142''. These form a lens triplet. The first lens 130'', the second lens 132'' and the third lens 142'' are formed integrally, for example by gluing and/or optical bonding. Together they form a lens system 128''.

The first lens 130'' is made of a first glass and the second lens 132 is made of a second glass. The first glass and the second glass are selected to deviate in opposite ways from normal dispersion glass. In this regard, reference is made again to FIG. 7 for illustration purposes.

For example, the first glass has an Abbe number d of 59.71, a refractive index m of 1.53996 and a dispersion nF - nc of 0.009120. The second glass, for example, has an Abbe number Vd of 63.33, a refractive index m of 1.61800 and a dispersion nF - nc of 0.009758. The two glasses are therefore deliberately chosen to be different and deliberately such that their deviation from normal dispersion is opposite. This allows the lens arrangement 112'' to provide high-quality images over a wide spectral range.

In the present embodiment, the third lens 142'' is made of a third glass different from the first glass and the second glass. The third glass, for example, has an Abbe number d of 47.11, a refractive index m of 1.67003 and a dispersion nF - nc of 0.014380.

The first lens 130'' is a convex lens. The second lens 132'' is a concave lens. The third lens 142'' is a convex lens. By way of example, the first lens 130'' has one Radius of curvature of 8.5 mm to . Furthermore, by way of example, the second lens 132″ has a radius of curvature of −7.8 mm. In addition, by way of example, the third lens 142″ has a radius of curvature of 82 mm.

The correction pair arrangement 134 '' has an aperture 144 '' which is arranged in the area of the second plane of symmetry 136 ''. The aperture 144'' has a smaller diameter than the rod lenses 112'' and the correction elements 124''.

In the present case, no aperture is arranged in the area of the further correction pair arrangement 138''. In other embodiments, however, as an alternative or in addition to the aperture 144' of the first correction pair arrangement 134'', an aperture can be arranged in the area of the further correction pair arrangement 138''.

Fig. 12 shows a schematic representation of images of a line pattern performed with the first endoscope device 110, the second endoscope device 110' or the third endoscope device 110''. In contrast to the above-explained imaging of a line pattern with a lens arrangement according to the prior art, a comparatively sharp imaging of the line pattern is possible in the entire spectral range between 400 nm and 100 nm. The combination of the appropriately selected lenses as well as the design and arrangement of the correction elements or Correction pair arrangements make it possible to image with high quality over a wide spectral range.

Fig. 13 shows a diagram regarding the wavelength dependence of an RMS point radius of the first endoscope device 110, the second endoscope device 110' or the third endoscope device 110''. The diffraction limit is shown as a dashed line. As can be seen, the RMS point radius is below the diffraction limit in at least a range between 480 nm and 1000 nm. At the blue edge of the range from 400 nm to 1000 nm, the RMS spot radius increases but is below 25 pm. From this it is clear why for different spectral ranges the ones shown in Fig. 12 high-quality images of the line pattern shown.

Fig. 14 shows a schematic representation of a lens arrangement 112 with anti-reflective surfaces 170. Such anti-reflective surfaces 170 can be used in any of the embodiments described above. Fig. 15 shows a schematic diagram that illustrates different reflectivity curves. The two dashed lines show conventional coatings that are optimized to work in the visible range or just beyond. Although a low reflectivity can be achieved in the visible range, this is accompanied by a sudden increase in reflectivity in the red or in the near infrared range. Such anti-reflective surfaces are only suitable to a limited extent for multispectral imaging, hyperspectral imaging, combined white light imaging and fluorescence imaging or other imaging for which imaging should be possible in a broad spectral range.

This is also shown in particular in FIG. 16, which shows a schematic diagram illustrating different transmission curves. The transmission curves were calculated for a lens arrangement that, for example, includes 30 surfaces. These are all provided with anti-reflective surfaces that correspond to those shown in Fig. 15 show reflectivity curves shown as dashed lines. Due to the large number of surfaces, the losses on the individual surfaces add up and the transmission drops rapidly in the red and near-infrared range.

In contrast, anti-reflective surfaces can be used in the endoscope devices 110, 110', 110'' described above, which are characterized by those shown in FIG. 15 and 16 are characterized by curves shown as solid lines. The reflectivity can be seen to be in the range between 400 nm and 1000 nm. above the values for a surface that is optimized for the visible area, but at a low level over the entire area. Specifically, that is

Reflectivity over the entire range at most 1%. That leads to a transmission that is also at a high level over the entire range, in this case at least over 75%.

As mentioned, the endoscope devices 110, 110', 110'' have great advantages, particularly when they are used for imaging in which a broad spectral range or at least wavelength ranges that are distributed over a broad spectral range are observed. It may therefore be expedient to use a broadband, preferably multimodal, lighting device 150. This is described in more detail below as an example. However, it goes without saying that the endoscope devices 110, 110′, 110″ can also be combined with other suitable lighting devices.

The lighting device 150 can, as mentioned, be multimodal. The lighting device 150 can be operated in different lighting modes in which it provides light for different imaging modes. In the present case, the lighting device 150 is operable in three basic modes, a multispectral mode, a fluorescence mode and a white light mode. Likewise, the imaging device 152 can be operated in different operating modes, specifically at least in a multispectral mode, a fluorescence mode and a white light mode. In the corresponding operating mode of the imaging device 152, the modes of the lighting device 150 are coordinated with one another.

Fig. 17 shows a schematic representation of the lighting device 150. The lighting unit 18 includes several lighting elements 20, 22, 24, 26, 28 that can be activated independently of one another. These are designed to emit light according to different emission spectra to provide illuminating light, i.e. H . The respective emission spectrum differs from lighting element to lighting element.

By way of example, the lighting elements 20, 22, 24, 26, 28 are designed as LEDs. Specifically, a first lighting element 20 is a red LED, a second lighting element 22 is a dark red LED, a third lighting element 24 is a blue LED and a fourth Lighting element 26 designed as a near-IR LED. The colored lighting elements 20, 22, 24, 26 each emit in a narrow band, for example with an emission peak at approximately the wavelengths 660 nm (first lighting element 20), 770 nm (second lighting element 22), 460 nm (third lighting element 24) and 940 nm (fourth lighting element 26) .

Furthermore, a fifth lighting element 28 is provided, which in the present case is a white light lighting element, such as a white light LED. The fifth lighting element 28 emits, for example, in a spectral range of approximately 400 to 700 nm. In other embodiments, laser diodes can also be used, in particular as colored lighting elements.

Depending on the lighting mode, some of the lighting elements 20, 22, 24, 26, 28 are activated at least temporarily, whereas other lighting elements 20, 22, 24, 26, 28 may not be used in the relevant lighting mode.

In the present case, a first group includes the first lighting element 20 and the fourth lighting element 26. The first group can additionally include the lighting element 22 and/or the lighting element 24. The first group is used for multispectral imaging, with the included lighting elements 20, 26 and possibly 22 and 24 each serving as a support point. In the multispectral mode, for example, the first lighting element 20 is first illuminated and an image is recorded. The fourth lighting element 26 is then illuminated and an image is taken. The images are based on remission, i.e. H. The light backscattered by the object to be imaged is examined. Through the two different support points, spectral information about the object to be imaged can be obtained. For example, certain types of tissue, a perfusion state, a tissue condition or the like can be assessed in this way.

Furthermore, a second group includes the first lighting element 20, the second lighting element 22 and the third lighting element 24. The second group is used for illumination in fluorescence imaging. For example, objects colored with appropriately selected dyes can be viewed. Different dyes can also be introduced into different types of tissue or the like, which are viewed at the same time. By specifically stimulating a specific dye, it is stimulated to fluoresce. The fluorescent light is then imaged. The first lighting element 20 is suitable, for example, for exciting the dye cyanine 5.5 (Cy 5.5). The second lighting element 22 is suitable for exciting the dye indocyanine green (ICG). The third lighting element 24 is suitable for stimulating the fluorescein dye.

Furthermore, a third group includes the fifth lighting element 28. In the present embodiment, the third group also includes the first lighting element 20 and the third lighting element 24. The third group serves to provide illuminating light for white light imaging. For this purpose, white light from the fifth lighting element 28 can be mixed with light from certain colored lighting elements, whereby spectral losses can be compensated for and/or a color temperature can be set specifically.

It can be seen that some of the lighting elements 20, 22, 24, 26, 28 are assigned to several groups, for example the first lighting element 20 of all three groups as well as the third lighting element 24 and possibly also the second lighting element 22 of the second and third groups.

Alternatively or additionally, it can also be provided that some or all of the lighting elements 20, 22, 24, 26, 28 are used in a hyperspectral mode. A broad excitation spectrum is then generated. In combination with a suitable hyperspectral detector, spectral information regarding the object to be imaged can then be recorded across the entire visible and near-IR spectrum. For this purpose, the imaging device 14 can include a pushbroom arrangement as a hyperspectral detector. In other embodiments, a whiskbroom arrangement, a staring arrangement and/or a snapshot arrangement is used. The imaging device 14 may be a hyperspectral imaging device. Regarding different methods of hyperspectral imaging and the components required for this are referred to the specialist article “Review of spectral imaging technology in biomedical engineering: achievements and challenges” by Quingli Li et al. Published in Journal of Biomedical Optics 18 (10), 100901, October 2013, as well as the specialist article “Medical hyperspectral imaging: a review" by Guolan Lu and Baowei Fei, published in Journal of Biomedical Optics 19(1), 010901, January 2014.

The lighting unit 18 comprises two crossed beam splitters 30, 32. These each include an output side 42, 44, an input side 37, 41 opposite the output side 42, 44 and two opposite input sides 34, 36, 38, 40. All input sides 34, 36, 37, 38, 40, 41 guide incident light to the corresponding output side 42, 44. The output side 42 of a first crossed beam splitter 30 faces an input side 41 of the second crossed beam splitter 32. The output side 44 of the second crossed beam splitter 32 faces the optical interface 16. The two crossed beam splitters 30, 32 are preferably arranged coaxially with one another and/or with the optical interface.

The lighting unit 18 may include suitable optical elements such as lenses and/or mirrors, not shown. Several lenses 78, 80, 82, 84, 86, 88 are shown as examples in FIG. A lens 78 is assigned to the optical interface 16 and couples light coming from the output side 44 of the second crossed beam splitter 32 into the optical interface 16. Furthermore, each of the lighting elements 20, 22, 24, 26, 28 can be assigned a lens 80, 82, 84, 86, 88. A particularly high degree of compactness can be achieved in particular if the lighting elements 20, 22, 24, 26, 28 are each arranged on input sides 34, 36, 37, 38, 40 of the at least one crossed beam splitter 30, 32 without an intermediate mirror. The lighting elements 20, 22, 24, 26, 28 can then be moved very close to the at least one crossed beam splitter 30, 32. The crossed beam splitters 30, 32 each include two beam splitter elements 90, 92, 94, 96. These can in principle be partially transparent, so that light from all input sides 34, 36, 37, 38, 40, 41 is redirected to the respective output side 42, 44. In the present embodiment, the beam splitter elements 90, 92, 94, 96 are selectively translucent. This is illustrated with further reference to Figure 3. The beam splitter elements 90, 92, 94, 96 can be filters that only reflect in a defined area, but otherwise have a high transmission. In Fig. 18, transmission curves 98, 100, 102, 104 of the beam splitter elements 90, 92, 94, 96 of the two crossed beam splitters 30, 32 are shown. One of the beam splitter elements 90, 92, 94, 96 is assigned to each of the colored lighting elements 20, 22, 24, 26 or each of the opposite input sides 34, 36, 38, 40. The beam splitter elements 90, 92, 94, 96 are selected such that they each reflect in the wavelength range in which the associated lighting element 20, 22, 24, 26 emits, but also largely transmit. For this purpose, notch filters can be used in the middle wavelength range, which can have the transmission spectra 100 and 102, for example. At spectral edges, high-pass or low-pass filters can also be used instead of notch filters, cf. Transmission spectra 98 and 104.

Due to the specific transmission spectra 98, 100, 102, 104 of the crossed beam splitters 30, 32, light from the fifth lighting element 28 is spectrally clipped. It can therefore be expedient, in the manner already mentioned, to specifically supplement the light blocked by the beam splitters 30, 32 by means of the lighting elements 20 and 24, possibly also 22 and/or 26. This can be supplemented specifically in those spectral ranges in which the beam splitters 30, 32 absorb and/or reflect light from the fifth lighting element 28, but in any case do not transmit it to the optical interface 16. The additionally used lighting elements 20, 24 and possibly 22 are preferably operated with reduced power or with adapted power. The aim here can be to at least largely restore the original spectrum of the fifth lighting element 28. In some embodiments, the fifth lighting element 28 can alternatively be a green lighting element, or Generally speaking, a colored luminous element that emits primarily in the spectral range that the at least one beam splitter 30, 32 transmits. For example, the fifth lighting element 26 in such embodiments can be an LED with an emission peak at approximately 530 nm. A green laser diode can also be used for this. It can be provided that color mixing takes place in the white light mode and in particular that no individual white light source such as a white light LED is used, but rather that white light from separate lighting elements is mixed in a targeted manner.

It goes without saying that, in the case of suitable dyes, such a green luminous element can also be used in fluorescence mode. Alternatively or additionally it could be usable in multispectral mode.

The lighting unit 18 defines a common optical path 54 into which emitted light from the lighting elements 20, 22, 24, 26, 28 can be coupled. The common optical path 54 extends from the output side 44 of the second crossed beam splitter 32 to the optical interface. In the present case, the common optical path 54 is arranged coaxially with the fifth lighting element 26.

In the embodiment shown, the lighting elements 20, 26 of the first group are arranged in such a way that light emitted by the lighting elements 20, 26, starting from the respective lighting element 20, 26 to the optical interface 16, each travels through a light path of at least essentially the same length . The lighting elements 20, 26 of the first group each have a light-emitting surface 56, 58. The light emitting surfaces 56 , 62 are arranged equidistantly with respect to the common optical path 54 . In the present case, this is achieved in that the two lighting elements 20, 26 are at the same distance from the beam splitter 32 assigned to them (here, for example, the second beam splitter 32), in particular from its opposite input sides 38, 40. are arranged. The light is coupled from the crossed beam splitter 32 into the common optical path 54.

The beam splitters 30, 32 are in particular arranged such that light-emitting surfaces 56, 58, 60, 62, 64 of the lighting elements 20, 22, 24, 26, 28 are each arranged equidistantly with respect to their assigned crossed beam splitter 30, 32.

By using crossed beam splitters 30, 32 and lighting elements 20, 22, 24, 26, 28 that can be used together for different modes, the lighting unit 18 or the lighting device 12 has a high degree of compactness. In addition, the equidistant arrangement can ensure that no spectral shifts occur when the imaging device 14 or its light guide is rotated relative to the optical interface 16.

It is understood that a different number of lighting elements 20, 22, 24, 26, 28 and/or a different number of crossed beam splitters 30, 32 can be used. The use of crossed beam splitters 30, 32 has proven to be particularly useful. In other embodiments, however, other types of beam splitters and/or other optical elements can be used to couple light from the lighting elements 20, 22, 24, 26, 28 into the optical interface 16.

Reference symbol list

110 endoscope device

112 lens arrangement

114 optical axis

116 eyepiece

118 lens

120 first plane of symmetry

122 rod lens

124 correction element

126 optical system

128 lens system

130 first lens

132 second lens

134 correction pair arrangement

136 second plane of symmetry

138 correction pair arrangement

140 third plane of symmetry

142 third lens

144 aperture

146 Endoscope

148 imaging system

150 lighting device

152 imaging device

154 image capture unit

156 display

158 image capture sensors

160 shaft

162 distal end

164 proximal end

166 fourth plane of symmetry

168 correction pair arrangement

170 anti-reflective surface

172 lens

Claims

Expectations

1. Endoscope device (110), in particular for hyperspectral and/or multispectral imaging, comprising a lens arrangement (112) which defines an optical axis (114) and which is designed to optically couple an eyepiece (116) to an objective (118). , wherein the lens arrangement (112) is set up for a given focusing both over a large part of the visible range and in the near-infrared range for a substantially equivalent forwarding and imaging of light, wherein the lens arrangement (112) with respect to a first plane of symmetry (120), which is perpendicular to the optical axis (114), is symmetrical, and wherein the lens arrangement (112) comprises: at least six rod lenses (122); at least two correction elements (124), which together with the rod lenses (122) define an optical system (126) and which each comprise a lens system (128) with at least a first lens (130) and a second lens (132), the first Lens (130) is made of a first glass and the second lens (132) is made of a second glass, the first glass and the second glass having different Abbe numbers and a relative partial dispersion of the first glass and a relative partial dispersion of the second glass differ in the opposite manner from normal dispersion glass; and at least one correction pair arrangement (134) comprising two of the correction elements (124) which are symmetrical to one another with respect to a second plane of symmetry (136) which is perpendicular to the optical axis (114).

2. Endoscope device (110) according to claim 1, wherein the first plane of symmetry (120) and the second plane of symmetry (136) are identical.

3. Endoscope device (110) according to claim 1 or 2, wherein the lens arrangement (112) comprises at least one further correction pair arrangement (138), the further Correction pair arrangement (138) comprises two further correction elements (124) which are symmetrical to one another with respect to a third plane of symmetry (140) which is perpendicular to the optical axis (114). The endoscope device (110) of claim 3, wherein the second plane of symmetry (136) and the third plane of symmetry (140) are different from the first plane of symmetry (120). Endoscope device (110) according to one of the preceding claims, wherein the correction elements (124) each comprise at least a third lens (142) made from the first glass. Endoscope device (110) according to one of the preceding claims, wherein the correction elements (124) are each integrally formed with a rod lens (122). Endoscope device (110) according to one of the preceding claims, wherein the correction pair arrangement (134) comprises at least one aperture (144) which is arranged in the region of the second plane of symmetry (136). Endoscope device (110) according to one of the preceding claims, wherein the second lens (132) is a convex lens. An endoscope device (110) according to any one of claims 1 to 7, wherein the second lens (132) is a concave lens. Endoscope device (110) according to one of the preceding claims, wherein the lens arrangement (112) enables optical images in the range from 400 nm to 1000 nm which have an RMS point radius of at most 40 pm, preferably at most 35 pm and preferably at most 30 pm. Endoscope device (110) according to one of the preceding claims, wherein the lens arrangement (112) enables diffraction-limited optical images in the range from 480 nm to 1000 nm. Endoscope device (110) according to one of the preceding claims, wherein the lens arrangement (112) has a maximum RMS point radius of at most 8 pm, preferably at most 6 pm and preferably at most 4 pm. Endoscope device (110) according to one of the preceding claims, wherein the rod lenses (122) and the correction elements (124) have anti-reflective surfaces (164) which act in the visible region and in the near-infrared region. Endoscope device (110) according to claim 13, wherein the anti-reflection surfaces (164) in the range from 400 nm to 1000 nm each cause an average reflection of at most 2%, preferably at most 1% and preferably at most 0.6%. Endoscope device (110) according to claim 13 or 14, wherein the anti-reflective surfaces (164) in the range from 400 nm to 1000 nm each cause a maximum reflection of at most 3%, preferably at most 2% and preferably at most 1%. Endoscope device (110) according to one of the preceding claims, wherein the lens arrangement has an average transmission of at least 70%, preferably at least 80% and particularly preferably at least 85% in the range from 400 nm to 1000 nm. Endoscope device (110) according to one of the preceding claims, wherein the lens arrangement has a minimum transmission of at least 60%, preferably at least 70% and particularly preferably at least 80% in the range from 400 nm to 1000 nm. Endoscope device (110) according to one of the preceding claims, further comprising the eyepiece (116) and / or the objective (118). Correction pair arrangement (134) for a lens arrangement (112) of an endoscope (146), comprising at least two correction elements (124) which define an optical axis (114) and which are designed to form an optical system (126) together with a plurality of rod lenses (122). ) and each comprising a lens system (128) with at least a first lens (130) and a second lens (132), the first lens (130) made of a first glass and the second lens (132) made of a second glass is manufactured, wherein the first glass and the second glass have different Abbe numbers and wherein a relative partial dispersion of the first glass and the second glass deviate in an opposite manner from glass with normal dispersion; wherein the correction elements (124) are symmetrical to one another with respect to a plane of symmetry (120, 132, 140, 166) which is perpendicular to the optical axis. Correction pair arrangement (134) according to claim 19, further comprising an aperture (144) which is arranged in the region of the plane of symmetry (120). Endoscope (146) with an endoscope device (110) according to one of claims 1 to 18 and / or with a correction pair arrangement (134) according to claim 19 or 20. Imaging system (148), comprising: an illumination device (150) which is set up to to provide illuminating light in both the visible and near-infrared regions; an endoscope device (110) according to one of claims 1 to 18 and/or an endoscope (146) according to claim 21; and an imaging device (152) with an image capture unit (154) that is set up to capture multispectral and/or hyperspectral image data.