Visualization assembly for microsurgery

Abstract

The present invention relates to a visualization assembly (1) for microsurgery, comprising an imaging device (14), an illumination device (4), and a polarization determination assembly, which comprises at least two video cameras (2) and at least one further video camera (3) designed to capture light waves of a plurality of light wavelengths in the visible wavelength range, wherein an individual partial beam path of a beam path (6) is assigned to each of the three mentioned video cameras (2, 3), a plurality of polarization filter devices (20-24), and an evaluation device (13), wherein the at least one polarization filter device (21-24) is arranged to filter the light waves of three of the at least three video cameras (2, 3) in front of each other. The polarizing filter devices (20-24) arranged in each beam path (6) are adjusted or adjustable so that the polarizing filters (20-24) arranged in the beam path (6) in front of the at least one further video camera (3) mentioned and the at least one video camera (2) designed to capture light waves of multiple light wavelengths in the visible wavelength range are different from each other in their polarization effect, and the evaluation device (13) is designed to generate images with polarization contrast from the images captured by the video cameras (2, 3) and display said images by the imaging device (14).

Description

[Technical Field]

[0001] The present invention relates to a visualization setup for microsurgery (e.g., for a surgical microscope) equipped with an imaging device for generating an image representation having polarization contrast (e.g., a stereoscopic imaging device for generating a stereoscopic image representation having polarization contrast). The present invention also relates to a method for generating an image representation having polarization contrast (e.g., a stereoscopic image representation having polarization contrast) of an object to be imaged using a visualization setup for microsurgery. Furthermore, the present invention relates to a microscope (e.g., a surgical microscope). [Background technology]

[0002] Surgical microscopes are used in various fields of microsurgery, primarily in neurosurgery, spinal surgery, otolaryngology, and ophthalmic surgery. They are characterized by their large working distance (200mm-600mm) and moderate magnification (up to approximately 20x) for stereoscopic imaging. These characteristics allow for the simultaneous use of surgical instruments while viewing the surgical site in a sterile surgical field. In recent years, there has been a shift from analog to digital systems. Digital systems utilize cameras, 3D monitors, or other 3D playback systems (head-mounted displays (HMDs), digital eyepieces (binocular eye monitors - boom)) for image recording and display.

[0003] A key driving force behind the development of surgical microscopes is the user's demand for tissue differentiation. Depending on the field and application, this may include differentiating between tumor tissue and healthy tissue, differentiating between white and gray matter in the brain, improving the representation of blood vessels and nerves, visualizing phase objects (such as the lens and lens capsule) during cataract surgery, or visualizing membranes during retinal surgery. Digital surgical microscopes offer significant advantages in improving tissue differentiation because the camera system used can be utilized for this purpose.

[0004] From the user's perspective, particularly in the field of neurosurgery, the following requirements must be met for techniques used for tissue differentiation: (i) Differentiation of various tissue types must be performed in real time relative to 3D image data, i.e., without significant time delay for the user, such as a surgeon. In digital systems, this time should be less than 50ms. (ii) Tissue differentiation must be performed across the entire surgical site, typically with a diameter of approximately 10mm to 50mm. The resolution of tissue differentiation should correspond to, but may be less than, the resolution of the 3D image data (analog or digital). (iii) Tissue differentiation must be intuitively interpretable by the surgeon, and its applicational significance must be supported by clinical research. (iv) It must be possible to switch tissue differentiation on and off as needed. (v) The techniques used for tissue differentiation should not significantly increase the cost of the surgical microscope, especially its footprint. (vi) Ideally, tissue differentiation should be performed without the use of markers or dyes, because the approval process for these is time-consuming and they frequently cause side effects in patients.

[0005] The scientific literature discloses numerous techniques that can be used for tissue identification. In this context, optical techniques offer many advantages over non-optical methods such as ultrasound due to their superior integration and non-contact measurement capabilities. The most important optical techniques for tissue identification are fluorescence / autofluorescence detection (continuous and / or time-resolved), laser Doppler and laser speckle imaging, optical coherence tomography (OCT), Raman spectroscopy (coherent or non-coherent), narrowband imaging, and detection of the effect of biological tissue on the polarization state of light. Despite the publication of many scientific papers, the number of techniques that are commercialized is small, mainly because it is difficult to meet the aforementioned requirements.

[0006] Therefore, camera-based fluorescence techniques have become particularly prevalent in recent years, both in surgical microscopes and endoscopes, because they best meet the aforementioned requirements. These are currently based on three medically approved dyes: ICG, NAF, and 5-ALA. Applicably, these are used for tumor / non-tumor differentiation and blood flow visualization. The aforementioned fluorescence techniques using the three approved dyes meet requirements (i) to (v), but not requirement (vi). That is, they are only available when used in combination with pharmaceuticals. A further drawback of the aforementioned fluorescence options is the fact that they cannot differentiate all applicable tissue types. Some tumors do not absorb the aforementioned dyes. Furthermore, in neurosurgery, maintaining brain function during surgery is extremely important. For this purpose, it is necessary to identify the fibrous pathways (white matter) of the brain and differentiate them from tumors or the gray matter of the cerebral cortex. This is currently impossible with any of the aforementioned dyes. For this reason, techniques for differentiating tumors, blood vessels, and white and gray matter tissues are extremely necessary, especially in neurosurgery.

[0007] Of the aforementioned techniques, polarization is advantageous because, due to its underlying physical processes, it does not require dyes or pharmaceuticals and is sensitive to different tissue types. At the cellular level, tumors have a disordered structure, but fibrous pathways in particular represent highly ordered zones. From the literature, it is known that such structures have different effects on the polarization of the irradiated light.

[0008] The following section details the formal theory of Stokes vectors and Müller matrices relating to the interaction between optical elements and surgical site tissues under partial polarization. The Müller matrix is ​​a 4x4 transformation matrix of the Stokes vector of the illumination light, which, after multiplication, provides the Stokes vector at the detector's location. Therefore, knowledge of the Müller matrix and its 16 elements contains all the information about how an object responds to partial polarization. In the field of metrology, there are numerous polarimeters that measure the complete Müller matrix at a point or surface (e.g., https: / / mountainphotonics.de / product / axo-axostep / ). A Müller polarimeter consists of components such as a light source, a PSG (polarization state generator), a PSA (polarization state analyzer), and a detector (point or surface). In this case, the PSG and PSA can be implemented in different ways, for example, by rotating a phase difference element or by a fixed method using a ferroelectric element.For general technical background, see W. Singer, M. Totzeck, H. Gross, Handbook of Optical Systems, Vol.2 “Physical Image Formation”, Chap.26.2.9, pp.475ff in the series “Handbook of Optical Systems”, H. Gross (Editor), Wiley VCH[1], H. Engstrom, “Coherency matrix polarisation measurements: application to magnetooptic garnet films”, Appl. Opt.30(1991) 1730-1734[4], A. Pigula, NTClancy, S. Arya, GBHanna, DSElsonin: Video-rate dual polarisation multispectral endoscopic imaging, International Society for Optics and Photonics, pp.93330N-93330N-93334(2015)[5], and Wei Sheng et al, “Quantitative Analysis of 4×4 Mueller Matrix Transformation Parameters for See the document "Biomedical Imaging", Photonics 2019, 6, 34, doi:10.3390 / photonics6010034[6].

[0009] The following describes a method for determining polarization contrast from Stokes vectors, particularly for tissues under examination. Stokes vectors are a conventional method for representing partial polarization states in polarized optics [1]. Stokes vectors consist of four real components, the so-called "Stokes parameters," whose values ​​can be determined by measuring the transmittance of light passing through a specific polarizer.

number

[0012] , lin , , ,

[0013] , , , , , circ , , , , , , represents the transmittance after passing through a linear polarizer at 45°, and P 90 represents the transmittance after passing through a linear polarizer at 90°, and P 135 represents the transmittance after passing through a linear polarizer at 135°, and P R represents the transmittance after passing through a right-handed circular polarizer, and P L represents the transmittance after passing through a left-handed circular polarizer.

[0010] Therefore, the Stokes parameter S0 represents the light intensity. S1 specifies how large the difference is between the components of linearly polarized light in the x and y directions, i.e., the components of linearly polarized light in the horizontal and vertical directions. S2 specifies how large the difference is between the components of linearly polarized light at 45° and 135°, i.e., the components of diagonal linearly polarized light. S4 specifies how large the difference is between the components of light polarized in the right-handed and left-handed directions, i.e., the components of circularly polarized light.

[0011] An important characteristic evaluation parameter of light in tissue contrast is the degree of polarization g. This is the polarized component in the overall intensity,

Equation

[0012] <​​​​​​​​​​​​​​​​​​​​ It is.

[0014] The measurement principle of the Stokes vector is explained below. The measurement of six different polarizers and the overall intensity affects the definition of the Stokes vector. However, four polarizers are sufficient to clearly measure the Stokes parameters. The reason is that the sum of two orthogonal polarization states already represents the overall intensity, that is, I0 = P0 + P 90 = P 45 + P 135 = P R + P L (5) due to the fact that it is.

[0015] Therefore, the Stokes vector (1) can also be described as follows.

Number

[0016] Below, the Mueller matrix and its information content for tissues in particular will be described. The polarization effect of an object such as a tissue consists of converting the incident Stokes vector into an emergence vector. In the linear region, this conversion is described as follows by multiplication with a 4×4 matrix, which is the Mueller matrix,

Number

Number

[0017] Each Müller matrix element has a simple meaning in itself. They describe the component in which one Stokes parameter is excited by another Stokes parameter. Thus, for example, M 12 This represents the excitation of S1 by S2.

[0018] For example, as described in literature such as [2], decomposing the Müller matrix into fundamental polarization matrices is important for explaining the polarization of the structure. One such decomposition is, for example, the Lou Chippmann polar decomposition, in which the Müller matrix is ​​expressed as the product of the depolarization Müller matrix, the phase shifter Müller matrix, and the double absorber Müller matrix, as follows: M=M Dia M Ret M Depol (9) The depolarization Müller matrix is,

number

number

number

number

number

number

number

number

[0019] In addition to this known decomposition, there are numerous examples in the literature on polarization measurement of decomposing the Müller matrix into functions of fundamental matrices [2]. This decomposition uniquely and accurately represents the Müller matrix, which consists of depolarization, phase difference, and double absorption. However, to perform the decomposition correctly, it is also necessary to measure the entire Müller matrix. In such cases, Müller matrix decomposition is the preferred form of analysis.

[0020] However, in principle, polarizers are not perfect and must themselves be explained by the Müller matrix. However, as shown in [4] and explained below, this can be taken into account in the measurement process. At the stage of measuring the Stokes vector, it is necessary to take into account the fact that the available components are not polarization-optically ideal. However, it can be assumed that they do not depolarize. Thus, their effect on partial polarization is explained by the Jones matrix, which is known, but not necessarily simple. For example, the degree of polarization of a polarizer is only 0.9. It is certainly more reasonable to consider this property during evaluation rather than incorporating it into the error budget. According to [4], a general method for measuring the Stokes vector (or polarization matrix) can be established, but this only assumes that the Jones matrices of the polarization modification components are known, not that they have specific values. The basis of this method is the linearity of the polarization matrix transformation in the Jones matrix, as follows:

number

number

[0021] Four intensity measurements using four different L values ​​set up a system of linear equations, and P in It can be decided,

number

number

[0022] Coefficient A jk To determine, j You must multiply the following equations together.

number

number

[0023] In actual measurements, it is necessary to realize four different measurement Jones matrices using polarized optical components. There are various options for this. A standard method is specified in [4], which utilizes linear polarizers of 0°, 45°, and 90°, or a quarter-wave plate with a 90° lagging axis followed by a 45° polarizer. Alternative measurement methods use a rotating quarter-wave plate followed by a polarizer. Naturally, further configurations are also possible. In the case of a "good" measurement method, the accuracy of the measurement no longer depends on how precisely the components maintain predetermined values ​​(e.g., phase difference, extinction ratio), but only on how well these values ​​are known. A further important variable with respect to measurement accuracy is how far the components span across the orthonormal basis of the Jones vectors. In this case, the relative error of the Stokes vector components is directly introduced into the Müller matrix. However, given the precision of the components, the smaller the associated basis vectors realized by the measurement method (i.e., the sensitivity of the measurement method to a given Stokes vector component), the larger the relative error.

[0024] German Patent Application Publication No. 102017100904A1 describes an image conversion module for microscopes designed for polarization measurement using a polarizing mask. U.S. Patent Application Publication No. 2016 / 091702A1,German Patent Application Publication No. 10242983A1, Chinese Patent Application Publication No. 107490851A, German Patent Application Publication No. 102018110806A1, and International Publication No. 2016170816A1 (brochure) , and also JAEPYEONG CHA et al:"Real-time,label-free,intraoperative visualization of peripheral nerves and micro-vasculatures using multimodal optical imaging techniques",BIOMEDICAL OPTICS EXPRESS,vol.9,no.3,12 February 2018(2018-02-12),pages1097-1110 This describes surgical microscopes designed at least for partial polarization determination.

[0025] The greatest challenges in integrating a complete Müller polarimeter into surgical microscopes, or microscopes in general that require real-time evaluation, are the requirements of (i) real-time capability, (ii) stereoscopic vision, and (v) small installation space and low cost (see above). For this reason, surgical microscopes have so far only been equipped with simple crossed linear polarimeters for illumination and observation (see below). This literature describes various polarimeter approaches to meet the aforementioned requirements, but so far, none have been successful.

[0026] The ZEISS EXTARO surgical microscope (https: / / www.zeiss.de / meditec / produkte / zahnheilkunde / operationsmikroskope / extaro-300.html) exclusively uses linear polarizers. The first polarizer is positioned to rotate in and out of the illumination beam path of the surgical microscope, and two more polarizers are incorporated into two stereo beam paths, which can also rotate in and out of the illumination perpendicular to the polarizers. Appropriately, the polarizers are used to reduce reflections from the tooth surface ("no-glare mode").

[0027] In Figure 8 of the "3x3 Mueller polarimetric endoscope" in J.Qi,DSElson, Mueller polarimetric imaging for surgical and diagnostic application, J.Biophotonics 10,950-982(2017) / DOI 10.1002 / jbio.201600152[2], the linear polarizer is firmly positioned upstream of the illumination exit at the tip of the endoscope. The endoscope rotates around the optical axis and is fixed and aligned in three different positions during the measurement process. In this way, three different alignments of linear polarization can be achieved in illumination. A filter wheel incorporating three different polarizers is mounted in front of the camera in the observation beam path. Using this endoscope, a 3x3 submatrix of the Mueller matrix can be determined. The measurement time is 11.6 seconds. Rotating the endoscope during clinical use is virtually impossible.

[0028] Furthermore, [2] describes an endoscope for measuring a complete Müller matrix using rotational PSG and time-series PSA in 30 seconds (see Figure 10). This endoscope is unsuitable for clinical use or applications requiring real-time evaluation due to its long measurement time and the presence of a rotational element. Also, [2] describes a stereo endoscope with a linear polarizer covering the illumination and a single stereo channel at the tip. The second stereo channel measures polarization perpendicular to it (see Figure 11). In addition, the polarization measurement is combined with spectral narrowband imaging. While this endoscope meets the requirements for real-time capability and small installation space / low cost, it does not produce stereoscopic images for users such as surgeons. Furthermore, only a small portion of the Müller matrix (a 2x2 submatrix) is determined, and important information regarding the characteristics of the sample is not obtained.

[0029] The paper Vizet, J., Rehbinder, J., Deby, S. et al, In vivo imaging of uterine cervix with a Mueller polarimetric colposcope, Sci Rep7, 2471 (2017), https: / / doi.org / 10.1038 / s41598-017-02645-9[3] describes a "Müller polarimetric colposcope" equipped with PSG and PSA based on a ferroelectric modulator. This module is mounted below the colposcope and is rotatable in and out. The measurement time is approximately 1.6 seconds, and a complete 4x4 Mueller matrix is ​​measured. The colposcope is equivalent to a surgical microscope in terms of its optical structure. In this case, the polarimeter module is mounted below the main objective lens and has a monoscopic beam path. Therefore, this method cannot achieve real-time capability, stereoscopic vision, a compact structure, or low cost.

[0030] Three-dimensional tissue differentiation beyond the use of simple cross-polarizers in real time (less than 50ms) and with a large observation field (more than 1cm in diameter) is still unknown. [Overview of the project] [Problems that the invention aims to solve]

[0031] Given the background described above, the problems that the present invention aims to solve are to provide an advantageous visualization arrangement for microsurgery, an advantageous method for generating an image representation with polarization contrast by a visualization arrangement for microsurgery, and a microscope, particularly a surgical microscope. [Means for solving the problem]

[0032] The aforementioned problems are addressed by the visualization arrangement for microsurgery described in claims 1 and 13, and the claims 14 A method for generating an image representation having polarization contrast by a visualization arrangement for microsurgery described above, and claims 20This is solved by the microscope described. Dependent claims include further advantageous configurations of the present invention.

[0033] The visualization setup for microsurgery (e.g., for a surgical microscope) according to the present invention includes an imaging device (preferably a stereoscopic imaging device), an illumination device, and a polarization determination setup. The polarization determination setup includes at least two video cameras designed to capture light waves of multiple wavelengths in the visible wavelength range (i.e., the wavelength range of 400 nm to 780 nm), at least one additional video camera (preferably two additional video cameras), a plurality of polarization filtering devices, and an evaluation device. Each individual sub-beam path of the beam path is assigned to each of the three video cameras described above. Thus, the three video cameras described above can be arranged adjacent to each other in the beam path, or in other words, in parallel to each other with respect to the beam path. In this context, this does not necessarily mean a spatial or geometric parallel arrangement, or a spatially adjacent arrangement, but rather an arrangement that allows for the individual capture of light waves in different sub-beam paths of the beam path by the individual video cameras.

[0034] At least two video cameras for capturing multi-color visible light are, for example, RGB cameras. At least one additional video camera could be, for example, a fluorescent camera.

[0035] At least one polarization filtering device is positioned upstream of each of the three video cameras, for example, in the beam path upstream of each of the three aforementioned video cameras. Optionally, at least one polarization filtering device may be positioned downstream of the illumination device and upstream of the object space region (e.g., the object or surface being imaged) in the beam path. The polarization filtering devices are configured or configurable such that the polarization filters positioned in the beam path upstream of at least one designated additional video camera and at least one of the aforementioned video cameras, designed to capture light waves of multiple wavelengths in the visible wavelength range, are different from each other in their polarization effect. Thus, at least two, preferably three, polarization filtering devices are configured or configurable such that they are offset from each other upstream of the video cameras. For example, the polarization filtering devices are also configured or configurable such that the three polarization filters positioned in the beam path upstream of the three aforementioned video cameras are different from each other in their polarization effect, i.e., each of the three aforementioned video cameras receives light simultaneously with the other two video cameras, and the received light is different in its polarization from that of the other video cameras.

[0036] In this case, the object being imaged can be understood as a subject or a portion of a subject, such as human, animal, or plant tissue.

[0037] The evaluation device is designed to use images captured by a video camera to generate image representations with polarization contrast (e.g., two-dimensional or three-dimensional image representations) and to display these image representations, preferably stereoscopically, using an imaging device. In this process, the generated image representations with polarization contrast can be superimposed on the beam path of the imaging device. These image representations can also be partially transparently overlaid on image representations without polarization contrast. Thus, the generated image representations with polarization contrast can be superimposed or masked. In this process, the polarization filtering device may be switchable on or off.

[0038] In an advantageous modification, the evaluation device is designed to display a generated image representation with polarization contrast, overlaid by the imaging device on a white light image representation captured by at least two video cameras designed to capture light waves of multiple wavelengths within the visible wavelength range. The at least two video cameras may be the aforementioned at least two video cameras, but there may be more than three video cameras. In particular, the polarization filtering device may not be positioned at least sequentially in front of at least one of the video cameras for capturing multicolor visible light. Thus, at least one of the video cameras for capturing multicolor visible light can generate a high-resolution multicolor image representation, and the generated image representation with polarization contrast can be overlaid on the high-resolution multicolor image representation. For example, the polarization filtering device may be switchable in front of at least one of the video cameras for capturing multicolor visible light so that the image representation with the upstream polarization filter and the image representation without the upstream polarization filter are captured alternately, preferably at intervals of less than 100 ms (particularly less than 40 ms). As a result, high-resolution image representations of objects with and without polarization contrast can be captured using the same video camera. Alternatively, at least one additional video camera may be present, at least one of which is designed to capture a multicolor image representation of objects without polarization contrast. Image representations with polarization contrast can be displayed by overlaying them on the captured image representations.

[0039] For example, white light can be understood as light with a broadband color spectrum. In this case, the wavelength can be substantially within the visible range. The wavelength distribution is usually continuous. The broadband color spectrum of a "white light source" gives humans the impression of white. In this case, the color impression produced by the eyeball is involved. Therefore, this is a physiological effect, not a physical effect. In other words, the impression of white can be based on a different spectrum limited to the visible range.

[0040] The visualization setup can be configured as a visualization setup for a microsurgery device, for example, as a visualization setup for a surgical microscope, particularly a surgical microscope designed for neurosurgery. The visualization setup preferably has a fully digital configuration.

[0041] When the visualization setup is configured as a component of a microscope, the microscope can be configured as a full digital microscope, particularly a surgical microscope. The visualization setup can be designed to record and display white light video data and / or fluorescence video data in real time and stereoscopically, and in particular, to display the above data in real time with a generated image representation having polarization contrast overlaid. When used as a component of a surgical microscope, the surgical microscope can preferably be designed for neurosurgical procedures. This may have an object surface or plane having a range or diameter of 10 mm to 50 mm. Preferably, the resolution of the generated image representation with polarization contrast is lower than the resolution of the (stereoscopic) image representation without polarization contrast displayed by the (stereoscopic) imaging device, or the resolutions match. For example, the aforementioned resolutions may differ from each other by less than 10%.

[0042] In further modifications, the meaning of each determined polarization contrast can be appliedly stored for specific applications, and the display format can be switched on or off. For example, in neurosurgical applications, the type of tissue imaged by polarization decomposition, or tissue features that can be derived from the polarization decomposed image representation, can be displayed. For this purpose, a complete Müller matrix can be determined for individual tissue types in clinical studies. Clinically relevant elements or elements generally relevant to each application can be derived for individual tissue types from the analysis of the Müller matrix. Then, within the scope of the visualization setup used, for example, within the scope of a microscope, only the relevant elements of the Müller matrix can be determined, or the Stokes vector components required for this purpose can be measured. The visualization setup can be designed to determine a fixed reduced Müller matrix.

[0043] The advantages of the visualization setup according to the present invention are real-time capability, small installation space, low cost, and the provision of an integrated polarization measurement technique that optionally meets the requirements for stereoscopic vision. In a modified form as a visualization setup for surgical microscopes, the present invention enables improved tissue differentiation, particularly in the field of neurosurgery. The visualization setup according to the present invention can simultaneously capture data that enables the determination of Stokes vectors and complete Müller matrices, or Müller matrix elements or coefficients, which are essential for each application.

[0044] In an advantageous modification, at least one polarization filtering device, for example, at least three, for example, four polarization filtering devices, positioned upstream of three, for example, four video cameras, preferably all of the aforementioned polarization filtering devices, include a plurality of polarizers different from each other, for example, at least four polarizers different from each other. At least one of the polarization filtering devices may include a filter wheel for switching between the plurality of different polarizers. In this way, each polarizer of the plurality of polarizers can be introduced into the beam path. For example, at least one of the polarization filtering devices may include at least three, in particular four linear polarizers and, optionally, at least one circular polarizer. For this purpose, at least one of the above polarization filtering devices may include one or more phase difference elements, at least a variable phase shifter, and / or a ferroelectric element, etc.

[0045] In a favorable configuration of the modified version having four cameras, i.e., if the polarizers of the individual polarization filtering devices introduced into the beam path are appropriately selected, at least three, preferably all four, of the four polarizers positioned upstream of the video camera will differ from one another in terms of their polarization effect. For example, three of the polarizers may be linear polarizers selected from, for example, polarizers P0, P45, P90, and P135 shown in Figure 3, and one polarizer may be a circular polarizer, or three or four of the polarizers may be linear polarizers. Filters with identical polarization effects can be positioned or configured upstream of the video camera, designed to capture light waves of multiple wavelengths in the visible wavelength range. Preferably, their polarization effects are orthogonal to polarizers positioned downstream of the illumination device and upstream of the object being imaged, by option.

[0046] In a favorable modification, at least one, for example, two, of at least one additional video camera is designed to capture monochrome light, i.e., light of a defined wavelength or a defined wavelength range, particularly fluorescent light. In this case, the captureable wavelength range may exceed the visible wavelength range.

[0047] In further modifications, the aforementioned video cameras, for example, at least one of the three video cameras described above, can take the form of a polarization camera. For example, a polarization camera may include four linear polarizers at the pixel level. A polarization camera may include at least one circular polarizer instead of one of the four linear polarizers at the pixel level, i.e., it may include three linear polarizers and one circular polarizer. A polarization filtering device located upstream of a video camera that does not take the form of a polarization camera, i.e., upstream of a video camera designed to capture light waves of multiple wavelengths in the visible wavelength range, may include or be configured as a circular polarizer. This can be realized in the form of a combination of a linear polarizer and a phase shifter, for example, a 0-degree quarter-wave plate element.

[0048] The evaluation device is advantageously designed to determine (e.g., calculate) a set of Müller matrix coefficients, particularly a finite set, from images captured by a video camera, and then determine the polarization contrast derived therefrom.

[0049] In a particularly advantageous configuration, a polarization filtering device, optionally positioned downstream of the illumination device and upstream of the object space region in the beam path, is designed to simultaneously polarize at least two defined mutually offset wavelengths, e.g., two defined mutually offset wavelength ranges, in a offset manner, i.e., distinct from one another. This allows for the simultaneous acquisition of a relatively large amount of data, which in turn allows for the determination or confirmation of a relatively large number of Müller matrix coefficients. As a result, stronger polarization contrast can be determined, and thus, a high-quality image representation with polarization contrast can be generated. Furthermore, for different polarization information relating to the object under inspection, simultaneously available detection channels (e.g., the number of camera sensors in an RGB camera), optionally spectrally encoded detection channels, can be used. Thus, polarization and spectrum can be designed so that multiple detection channels (e.g., each detection channel) supply different information (e.g., tissue information).

[0050] At least one of the polarization filtering devices may include a color filter or a wavelength filter, and / or a wavelength-selective polarizer or a wavelength-specific polarizer. In particular, the above configuration can be realized using these. Each polarization filtering device may include, for example, a notch filter, in particular a polarization notch filter, and / or a bandpass filter, in particular a polarization bandpass filter.

[0051] Generally, the polarization filtering devices described above may include filters for fluorescence and / or polarization (particularly wavelength-specific polarization). For example, a first polarization state for at least one first wavelength or a first wavelength range, and a second polarization state for at least one second wavelength or a second wavelength range may be set or configurable.

[0052] The lighting device can be designed to emit dichromatic or polychromatic light. Preferably, the lighting device is designed to emit polychromatic light, and the polarization filtering device located downstream of the lighting device and upstream of the object space region in the beam path includes at least one, for example, two notch filters, preferably polarizing notch filters, and / or at least one, for example, two bandpass filters, preferably polarizing bandpass filters.

[0053] Furthermore, the visualization setup may include at least one beam splitter, such as a dichroic beam splitter. This dichroic beam splitter can be placed in the beam path between the object space region and the video camera.

[0054] At least one video camera designed to capture or receive light waves of multiple wavelengths in the visible wavelength range can be configured as a 3-chip camera or a 1-chip camera.

[0055] An alternative visualization configuration for microsurgery according to the present invention, which is an alternative to the visualization configuration described above, includes an imaging device (e.g., a stereoscopic imaging device), an illumination device, and a polarization determination configuration. The polarization determination configuration includes two polarization cameras, each to which an individual partial beam path of a beam path is assigned, and an evaluation device. The evaluation device is designed to generate an image representation with polarization contrast using images captured by the polarization cameras, and to display the image representation, preferably stereoscopically, by the imaging device. The alternative visualization configuration according to the present invention provides an equivalent solution to the visualization configuration according to the present invention described above. Both of these variations use the same technical effects to generate an image representation with polarization contrast and have the same features and advantages as described in detail above. In particular, the alternative visualization configuration according to the present invention may include the aforementioned features and characteristics that are optional in the context of the visualization configuration according to the present invention described first.

[0056] ReviewThe valence device is designed to display a generated image representation with polarization contrast overlaid on a white light image, and the white light image representation is captured by two polarization cameras. In this case, the display is performed by an imaging device.

[0057] A method according to the present invention for generating an image representation of an object with polarization contrast (e.g., a stereoscopic image representation with polarization contrast) by a visualization arrangement according to the present invention for microsurgery (particularly for surgical microscopes) as described above includes the following steps: An illumination device irradiates the object with light waves, particularly in the visible wavelength range, and optionally in a wider wavelength range. At least two polarization cameras or at least three video cameras capture or receive the light waves emitted by the object after interaction between the irradiated light waves and the object. An image representation with polarization contrast, preferably a stereoscopic image representation with polarization contrast, is generated based on the generated polarization state of the irradiated light waves and / or the analyzed polarization state of the captured or received light waves. The method according to the present invention has the already described features and advantages of the visualization arrangement according to the present invention.

[0058] In a favorable modification, a light wave with a defined polarization state is irradiated by an illumination device and a polarization filtering device positioned in the beam path downstream of the illumination device and upstream of the object. The polarization state of the received light wave can be analyzed by the aforementioned video camera and a polarization filtering device positioned in the beam path upstream of the video camera. An evaluation device can be used to generate an image representation with polarization contrast (e.g., a stereoscopic image representation) based on the analyzed polarization state of the captured or received light wave, where the set of Müller matrix coefficients is determined by the image captured by the video camera and / or polarization camera, and the polarization contrast derived from these coefficients is determined (in particular, calculated).

[0059] Image representations with polarization contrast (e.g., stereoscopic image representations) are preferably generated within a time interval of less than 50 ms. The resolution of the generated image representations with polarization contrast (e.g., stereoscopic image representations) is preferably less than 10% different from the resolution of the corresponding image representations without polarization contrast (e.g., stereoscopic image representations). Particularly preferably, the image representations with polarization contrast (e.g., stereoscopic image representations) are generated within a time interval of less than 50 ms and displayed overlaid on the multicolor image representations (e.g., stereoscopic image representations).

[0060] Within the scope of the method according to the present invention, photogrammetry can be applied to a video signal to, for example, identify and evaluate the polarization of each corresponding pixel within a stereo channel. In this process, a numerical value reflecting the polarization characteristics can be calculated for each pixel. From this, a color value reflecting the polarization characteristics can be derived for each pixel. In particular, the polarization characteristics can be represented three-dimensionally in real time, either by themselves or by overlaying them on a white light image.

[0061] A microscope according to the present invention, which may be a surgical microscope (e.g., a neurosurgical microscope), is designed to include the visualization arrangement according to the present invention described above and / or to carry out the method according to the present invention described above. It has the features and advantages already specified above. A microscope according to the present invention is preferably configured three-dimensionally and / or is configured partially or fully digitally.

[0062] A microscope, particularly a surgical microscope, may include a variable focal length optical system unit, i.e., a variable focal optical system unit (varioscope) and / or at least one objective lens, and / or at least one zoom optical system unit and / or a peripheral camera, i.e., a video camera for capturing the spatial region around the area of ​​the object being imaged by the microscope, positioned in the beam path upstream of at least one video camera.

[0063] The present invention will be described in detail below with reference to the accompanying figures, based on exemplary embodiments. While the present invention is more specifically illustrated and described in detail by preferred exemplary embodiments, the present invention is not limited to the disclosed embodiments, and those skilled in the art can derive other modifications therefrom without departing from the scope of protection of the present invention.

[0064] The figures are not necessarily accurate in detail or to scale, and may be enlarged or reduced for clarity. Therefore, it should be understood that the functional details disclosed herein are not intended to be limiting, but merely illustrative to guide those skilled in the art in various ways of using the invention.

[0065] As used herein, the expression "and / or" means that when used with a set of two or more elements, any one of the enumerated elements may be used alone, or any combination of two or more of the enumerated elements may be used. For example, if a structure is described that includes components A, B and / or C, that structure may include A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B and C. [Brief explanation of the drawing]

[0066] [Figure 1] A schematic diagram of a surgical microscope according to the present invention, having a visualization arrangement according to the present invention, is shown in block diagram form. [Figure 2] The polarization optical operation mode of the visualization arrangement according to the present invention is schematically shown in the form of a block diagram. [Figure 3] A schematic diagram of an exemplary polarizing filter is shown. [Figure 4] A schematic diagram of a polarizing optical operating mode for an exemplary modified form of the visualization arrangement according to the present invention is shown in block diagram form. [Figure 5] A schematic diagram of a polarizing optical operating mode for an exemplary modified form of the visualization arrangement according to the present invention is shown in block diagram form. [Figure 6] A schematic diagram of a polarizing optical operating mode for an exemplary modified form of the visualization arrangement according to the present invention is shown in block diagram form. [Figure 7] A schematic diagram of a polarizing optical operating mode for an exemplary modified form of the visualization arrangement according to the present invention is shown in block diagram form. [Figure 8] A schematic diagram of a polarizing optical operating mode for an exemplary modified form of the visualization arrangement according to the present invention is shown in block diagram form. [Figure 9] The principle of a polarizing camera is outlined below. [Figure 10] Two schematic diagrams illustrating possible illumination of an object region are shown. [Figure 11] A schematic diagram illustrating the realization of illumination as shown at the bottom of Figure 10 using a polarizing notch filter is shown. [Figure 12] The modified version shown in Figure 11 is schematically implemented using a polarizing bandpass filter. [Figure 13] A schematic block diagram shows an exemplary variation of the visualization arrangement according to the present invention, illustrating the polarization optical operating modes using two different wavelengths. [Figure 14] A schematic block diagram shows an exemplary variation of the visualization arrangement according to the present invention, illustrating the polarization optical operation mode using two different wavelengths and two polarization cameras. [Figure 15] A schematic block diagram shows an exemplary variation of the visualization arrangement according to the present invention, illustrating the polarization optical operating modes using two different wavelengths. [Figure 16] The spectral resolution of prisms and filters is shown in general terms. [Figure 17] The method according to the present invention is schematically shown in the form of a flowchart. [Modes for carrying out the invention]

[0067] Figure 1 schematically shows a surgical microscope 1 according to the present invention in block diagram form. For example, the surgical microscope 1 can be designed for use in the range of neurosurgery and spinal surgery. The surgical microscope 1 includes a visualization setup having an illumination device 4, an object plane or object space region 5 on which an object to be magnified and imaged can be placed, for example, a stereoscopic imaging device, and a polarization determination setup. The illumination device 4 is designed to illuminate the object space region 5, that is, to irradiate an object with light waves. The beam path is identified by an arrow denoted by reference numeral 6.

[0068] Preferably, the microscope 1 takes the form of a fully digital microscope. The microscope 1 is preferably designed to record and display both white light video data and fluorescence video data stereoscopically in real time. This is achieved, in each case, by using two video cameras 2 (VIS cameras, e.g., RGB cameras) designed to capture light waves of multiple wavelengths in the visible wavelength range, and at least one further video camera 3, preferably two further video cameras 3 (fluorescence cameras) as shown, configured as a monochrome camera for increased sensitivity and designed to capture fluorescence. The two VIS cameras 2 are preferably 3-chip or 1-chip cameras. The fluorescence cameras 3 may also be designed to capture light waves beyond the visible range.

[0069] In addition, the microscope 1 includes a variable focal length optical system unit (varioscope) 7, two zoom optical system units 8, an aperture element 19, and two video objective lenses 9. In this case, the variable focal length optical system unit (varioscope) 7, the two zoom optical system units 8, and the two video objective lenses 9 are positioned in the beam path 6 between the object space region 5 or an object placed in the object space region and the aforementioned video cameras 2 and 3. In Figure 1, a laser autofocus device 10 is positioned in the beam path 6 between the variable focal length optical system unit 7 and the zoom optical system units 8. A beam splitter 12 is positioned in each beam path 6 between the video objective lenses 9 and the aforementioned video cameras 2 and 3. The beam splitter 12 generates individual partial beam paths, and each individual partial beam path is assigned to the respective video cameras 2 and 3 in the beam path 6. Furthermore, the microscope 1 optionally includes a peripheral camera 11, which can be used to capture a wide field of view (e.g., a magnified surgical site) around the object region captured by the microscope, and can be used for tool tracking and navigation functions.

[0070] The polarization determination configuration includes, in addition to the four video cameras 2 and 3 mentioned above, a plurality of polarization filtering devices 20 to 24 and an evaluation device (not shown here). In this case, each of the polarization filtering devices 21 to 24 is positioned upstream of each of the four video cameras 2 and 3, and the polarization filtering device 20 is positioned downstream of the illumination device 4 and upstream of the object space region 5 in the beam path 6. In this case, the polarization filtering devices 21 to 24 are configured or can be configured to be different from each other in their polarization effect, in each case, the polarization filters 21 to 24 positioned upstream of at least one, preferably both, of two designated additional video cameras 3, and at least one, particularly both, of the aforementioned video cameras 2, which are designed to capture light waves of multiple light wavelengths in the visible wavelength range in the beam path 6. In other words, the polarization settings of at least one polarizing device 22, 23 located upstream of one of the video cameras (VIS cameras) 2 designed to capture visible light are different during operation from the polarization settings of at least one polarizing device 21, 24 located upstream of one of the further video cameras 3 (e.g., a fluorescence camera).

[0071] The polarization determination configuration allows for the analysis of the polarization state of light emitted from object 5, and multiple polarization measurements can be performed simultaneously using multiple video cameras 2 and 3. This enables the capture and evaluation of necessary data in real time. To generate a polarization-decomposed (e.g., three-dimensional) overall image of the object, for example, differently configured polarization filter wheels or different polarizers 20-24 can be placed in the beam path 6 upstream of the four cameras 2 and 3 and downstream of the illumination device 4. These include excitation and observation filters suitable for the aforementioned fluorescence method options, as well as polarizers suitable for polarization measurements.

[0072] When using the alternative visualization configuration according to the present invention as described at the beginning, the video camera 2 is configured as a polarization camera. In this modification, the additional video camera 3, beam splitter 12, and polarization filtering configurations 20-24 can be omitted.

[0073] In the following, a simplified diagram is used to explain the polarization optics of the system. Figure 2 schematically shows the polarization optics operating mode of the visualization arrangement according to the present invention in the form of a block diagram. In this case, the evaluation device 13 is used to perform analysis and evaluation of image data captured by the four cameras 2, 3 and to synthesize the data to form a three-dimensional overall image with polarization contrast. The generated overall image is visualized by the stereoscopic imaging device 14 or displayed to the user. Data transfer between the video cameras 2, 3 and the evaluation device 13 and between the evaluation device 13 and the stereoscopic imaging device 14 is identified by reference numeral 15. Within the scope of the analysis and evaluation of the acquired data, Stokes vectors or a portion thereof are preferably determined, and a number, preferably more than four, Müller matrix coefficients are determined (in particular, calculated). The polarization contrast is determined using the determined Müller matrix coefficients.

[0074] Figure 3 schematically shows exemplary polarizing filters and their designations. In this case, the polarization effect of the filter is indicated by the direction of transmitted polarization. Polarizers 20-24 each include a number (preferably multiple) different polarizers, for example, one or more of the polarizers shown in Figure 3. Preferably, the polarization can be set individually in each of the polarizing filtering devices.

[0075] To measure the complete Stokes vector, four different polarizers are required at filter positions 21–24. An example is shown in Figure 4, and the polarizers can also be classified to differ among the four filter positions 21–24. In surgical microscopes, the linear polarization component may be of primary interest, so the circular polarizer can be optionally omitted. Then, as shown in Figure 5, the circular polarizer can be replaced with, for example, a 135° filter to provide redundancy in determining the overall intensity.

[0076] In a further modification shown in Figure 6, the same polarizing filter is placed or installed in front of two visible light video cameras 2 (VIS camera or RGB camera) so as not to interfere with stereoscopic imaging. In this case, it is advantageous that the polarization of the illumination 4, 20 is set to be orthogonal to the polarization of the filters 22, 23 upstream of the two visible light video cameras 2. This is shown in Figure 7, where Stokes vector components S0, S1, S2 can be measured without interfering with stereoscopic imaging.

[0077] In digital surgical microscopes, Stokes parameters can also be measured using one or more polarizing cameras that perform the four measurements necessary to determine the Stokes vector using small polarizing filters on camera pixels. In this case, at least one of the four video cameras 2, 3 is a polarizing camera 17. Preferably, one of the additional video cameras 3 is a polarizing camera, for example, as shown in Figure 8. In this context, the polarizing filtering arrangement 24 in Figure 8 is arbitrary. The principle of the polarizing camera is shown in Figure 9. Each of the four adjacent pixels 16 in a plane is provided with a polarizer offset from each of the other polarizers.

[0078] For example, a polarizing camera available from Sony Corporation has a resolution of 5 megapixels and achieves a frame rate of 23 frames / second. This means that the time delay between two images is 43ms, which is slightly below the required specification of 50ms. In equation (1), the four polarizers are P0, P 45 , P 90 , P 135This corresponds to the fact that the first three Stokes parameters (S0, S1, S2) can be measured, but the fourth component S3 cannot. In tissue imaging in reflection, this limitation may be acceptable because the structural features are substantially linear, i.e., should mainly affect the linear polarization component. In deep tissue imaging, it can be important that fibrous layers may be positioned obliquely to each other. This is equivalent to linear phase difference plates being combined in different orientations, which can result in rotation and, consequently, circular birefringence. To measure all Stokes parameters, for example, a 0° quarter-wavelength phase shifter can be superimposed on a 135° or 45° polarizer as shown in Figure 5. Combining these two results in a circular polarizer.

[0079] If the measurement of the Müller matrix is ​​incomplete, the Chipman-Lou resolution mentioned at the beginning is impossible. Furthermore, the essential goal of a surgical microscope with polarized contrast is not to measure the Müller matrix completely and accurately, but rather to provide the user (e.g., surgeon) with good tissue contrast. Many analyses have been conducted on this point in the past.

[0080] One variation is described in [6], which defines a set of parameters directly derived from Müller matrix coefficients, based on simulations of polarization effects on isotropic and anisotropic structures. In this case, it is sufficient to measure a finite set of Müller matrix coefficients and calculate the contrast derived therefrom. An example for this purpose from [6] is summarized in the table below.

[0081] [Table 1]

[0082] However, these are just a few examples. There are even more significant combinations of Müller matrix elements that can be used as image contrast for surgical microscopes.

[0083] The linear anisotropic media studied in [6] have a shape very similar to that of biological fibers and exhibit the following Müller matrix symmetry.

number

[0084] Only the subset of the 3x3 array is different from zero and is also symmetric. Therefore, we only need to decide on the six independent components I0, A, B, C, D, and E.

[0085] To measure a portion of the Müller matrix, illumination is required not only in one polarization state but in multiple polarization states. An obvious solution is to configure filter 20 to be rotatable or to complement it with a ferroelectric liquid crystal filter. However, in this case, illumination with multiple polarization states can only be performed sequentially in time. Since polarization imaging is already within the required specifications, time-sequential polarization illumination would clearly exceed the requirement of a time delay of 50 ms or less for tissue contrast. If time cannot be used as a parameter to distinguish the polarization of the illumination, the wavelength of the illumination light can be used within the scope of the present invention. By setting two polarization states at different positions in the spectrum, simultaneous illumination with two polarization states becomes possible. In that case, the relevant image can also be reconstructed using a spectral filter. That is, the illumination needs to be set to different polarization states in two narrow spectral bands. If a “normal color impression” is still desired, unpolarized light or light in any desired polarization state needs to be present around the above bands (see Figure 3). Otherwise, there is also the option of dichromatic illumination. For example, this can be achieved with two notch filters, as shown in Figure 10.

[0086] Figure 10 schematically shows two figures representing possible illumination of an object space region. Both figures plot the intensity I of the irradiated light as a function of wavelength λ. The upper figure shows dichromatic illumination with a first wavelength range 31 and a second wavelength range 32, where the two wavelength ranges 31 and 32 are in a polarized state that is offset from each other. The lower figure shows polychromatic illumination, where the two wavelength ranges 31 and 32 are in a polarized state that is offset from each other, and the remaining spectral range 33 is unpolarized. For example, this can be achieved by two notch filters, as shown in Figure 11. In this case, the two narrowband polarized spectral components 31 and 32 are achieved by passing unpolarized light through two narrowband polarizing notch filters. To realize the concept shown in Figure 11, a polarizing bandpass filter can be used in reflection, for example, as shown in Figure 12. Figure 12 shows the operating modes of a polarization bandpass filter 34 from Semrock (https: / / www.semrock.com / a-new-class-of-polarization-optics-designed-specifically-for-lasers.aspx). On the left, the beam paths of three different wavelengths λ1, λ2, and λ3 and their respective linear polarizations s and p are shown. In this case, s and p represent mutually orthogonal linear polarizations. On the right side of Figure 12, a graph is shown plotting the transmittance T through the filter 34 as a function of wavelength λ and polarizations s and p.

[0087] When using the configuration shown in Figure 13, depending on the irradiated and measured polarization state, the components of the measurable Müller matrix (e.g., M) can be determined. 00 M 01 M 10 M 11 ) are different. In the modified example shown in Figure 13, wavelengths or wavelength ranges λ1 and λ2 polarized perpendicularly to each other are irradiated, and each polarized wavelength is analyzed by different cameras. In the modified example shown, wavelength λ1 is analyzed by a first video camera (RGB camera) 2 for visible light and a first further video camera 3, and wavelength λ2 is analyzed by a second video camera (RGB camera) 2 for visible light and a second further video camera 3.

[0088] Naturally, other configurations are possible; for example, RGB camera 2 can be replaced with monochrome camera 3, and vice versa. However, without a polarization camera, in the modified configuration shown in Figure 13, due to spectral splitting, only two Stokes vector components S0 and S1 can be measured, instead of three or four. However, these could also be S0 and S2, in which case the Müller matrix component M 00 M 02 M 20 M 22 It will become available.

[0089] In the modified version shown in Figure 14, two polarization cameras 17 are used as additional cameras 3, and two input polarizations can be used to measure half of the Müller matrix, i.e., eight Müller matrix elements. In this case, filter 20 (not plotted here) is a polarization notch filter that polarizes only two wavelengths λ1 and λ2 in the unpolarized illumination spectrum. The remaining illumination spectrum is unpolarized. Filter 21 is a filter for wavelength λ1 and optionally for polarization 1, and filter 24 is a bandpass filter for wavelength λ2 and optionally for polarization 2. Alternatively, the neutral beam splitter can also take the form of a dichroic beam splitter, for example, a first wavelength with a first polarization and a second wavelength with a second polarization. This is more efficient in terms of optical budget, but comes at the expense of flexibility. The advantage of this method is that polarization provides an additional option that does not interfere with standard imaging.

[0090] Figure 15 shows a further embodiment of spectral coding in which the spectral characteristics of the RGB channels of two color video cameras 2 are advantageously used. As described in relation to Figure 14, filter 1 (not plotted here) is also a polarization notch filter in Figure 15, but here it is designed to illuminate at four different wavelengths with defined default polarizations. The polarizations of the different wavelengths may be different or partially identical. A one-chip or three-chip camera can be used as the video camera 2 (RGB camera). In the case of a one-chip camera, a Bayer filter separates one sensor into three spectrally separated pixel arrays, whereas in the case of a three-chip camera, spectral separation can be achieved between three sensors by using a splitter prism. The wavelength of filter 20 is selected in Figure 15 so that the RGB sensors detect wavelengths separately and there is no crosstalk between the various wavelengths. This can be achieved, for example, by illuminating at wavelengths of 400 nm, 540 nm, and 680 nm, as shown by the typical spectral sensitivities of the RGB sensors and the Bayer filter in Figure 16. Figure 16 shows the relative spectral sensitivity of the splitter prism (top) and Bayer filter (bottom) as a function of wavelength. The fourth wavelength of the illumination filter 20 is selected so that the two monochrome cameras 3 can detect signals spectrally separated from the RGB camera 2. This can be achieved, for example, by illuminating with wavelengths in the infrared wavelength range (e.g., 800 nm) to which the RGB camera 2 is no longer sensitive. Naturally, it is also conceivable that different wavelengths be selected and interference wavelengths be removed upstream of the sensor by appropriate notch filters. Thus, the filters 22 and 23 upstream of the RGB camera 2 are ideally designed as multibandpass filters for wavelengths of 400 nm, 540 nm, and 680 nm. At the same time, filters 22 and 23 can be designed to have different polarization characteristics. The filters 21 and 24 upstream of the further video camera (monochrome camera) 3 are designed as bandpass filters for the wavelength of 800 nm, and optionally, filters 21 and 24 also have different polarization characteristics.

[0091] The exemplary embodiment in Figure 15 illustrates a specific case and can be generalized as follows. In the first step, the number N of detection channels present in the system is determined. In the example shown in Figure 1, this is eight channels, with two additional video cameras 3 (monochrome cameras) supplying two channels each, and two visible light video cameras 2 (RGB cameras) supplying six channels. Here, the system is designed so that these N detection channels provide optimal tissue contrast for their respective applications. This is achieved by the fact that all N channels differ in at least one characteristic (e.g., spectrum and / or polarization).

[0092] A first possible exemplary embodiment of a system having eight detection channels is detection by illumination with eight spectrally separated polarizations and eight detectors that analyze in a spectrally separated manner by one polarization. A second possible exemplary embodiment of a system having eight detection channels is detection by illumination with two spectrally separated defined polarizations and eight detectors, with four detectors in each case analyzing the spectral region with four different analyzers.

[0093] Figure 17 schematically illustrates, in flowchart form, a method according to the present invention for generating an image representation (preferably a stereoscopic image representation) of an object having polarization contrast using the visualization setup described above (e.g., a visualization setup for a surgical microscope). The method includes, in step 41, irradiating an object with light waves using an illumination device; in step 42, capturing the light waves emitted from the object after interaction with the irradiated light waves using at least three video cameras or at least two polarization cameras; and in step 43, generating a preferably stereoscopic image representation having polarization contrast based on the generated polarization state of the irradiated light waves and / or the analyzed polarization state of the captured light waves. For specific embodiments and variations of the method, please refer to the description of Figures 1 to 16. [Explanation of Symbols]

[0094] 1. Surgical microscope with visualization configuration 2 video cameras 3 video cameras 4 Lighting devices 5 Object area, object 6 Beam paths 7. Optical unit with variable focal length (varioscope) 8 Zoom Optical Units 9 Video objective lens 10. Laser autofocus device 11 Peripheral Cameras 12 Beam Splitter 13 Evaluation Devices 14. (3D) Imaging Device 15 (Image) Data Transfer 16 pixels 17 Polarizing Camera 19 Aperture element 20 Polarization filtering devices 21 Polarization filtering device 22 Polarization filtering devices 23 Polarization filtering devices 24 Polarization filtering devices 31 wavelength range 32 wavelength range 33 wavelength range 34 Polarizing bandpass filter 41. Irradiate with light waves. 42. Capture the light waves emitted from the object after the interaction between the irradiated light waves and the object. 43. Based on the generated polarization state of the irradiated light wave and / or the analyzed polarization state of the captured light wave, an image representation with polarization contrast is generated. I strength T transmittance λ wavelength s Linear polarization p linearly polarized light P0 0 degree polarizer P90 90-degree polarizer P45 45-degree polarizer P135 135 degree polarizer PC circular polarizer PN neutral polarizer

Claims

1. A visualization configuration (1) for microsurgery, comprising an imaging device (14), an illumination device (4), and a polarization determination configuration, The polarization determination configuration includes at least two video cameras (2) and at least one additional video camera (3) for capturing multicolor visible light, wherein each partial beam path of the beam path (6) is assigned to each of the three video cameras (2, 3), and includes a plurality of polarization filtering devices (20-24) and an evaluation device (13). At least one polarization filtering device (21-24) is placed in the beam path (6) upstream of each of the three of the at least three video cameras (2, 3). The polarization filtering devices (20-24) are configured or can be configured to be different from each other in their polarization effects, and are positioned in the beam path (6) upstream of at least one designated additional video camera (3) and the video camera (2) for capturing multicolor visible light. The evaluation device (13) is designed to generate an image representation having polarization contrast using images captured by the video cameras (2, 3), and to display the image representation using the imaging device (14). A visualization arrangement (1) characterized by the following.

2. The evaluation device (13) is designed to display the generated image representation having polarization contrast by overlaying it with the white light image representation captured by at least two video cameras (2) for capturing multicolor visible light, as captured by the imaging device (14). The visualization arrangement (1) according to claim 1, characterized in that

3. At least one polarization filtering device (20) is positioned in the beam path (6) downstream of the illumination device (4) and upstream of the object space region (5). The visualization arrangement (1) according to claim 1 or 2, characterized in that

4. At least one of the polarization filtering devices (20-24) includes a plurality of polarizers that are different from each other. The visualization arrangement (1) according to claim 1 or 2, characterized in that

5. Either the at least one additional video camera (3) is designed to capture monochrome light, or at least one of the video cameras (2, 3) takes the form of a polarizing camera. The visualization arrangement (1) according to claim 1 or 2, characterized in that

6. At least one polarization filtering device (22, 23) positioned upstream of a video camera (2) for capturing multicolor visible light includes a circular polarizer. The visualization arrangement (1) according to claim 5, characterized in that

7. The evaluation device (13) is designed to determine a set of Müller matrix coefficients using the images captured by the video cameras (2, 3), and to determine the polarization contrast derived from the coefficients. The visualization arrangement (1) according to claim 1 or 2, characterized in that

8. A polarization filtering device (20) positioned in the beam path (6) downstream of the illumination device (4) and upstream of the object space region (5) is configured to simultaneously polarize at least two defined, mutually offset wavelengths in a mutually offset manner. The visualization arrangement (1) according to claim 1 or 2, characterized in that

9. At least one of the polarization filtering devices (20-24) includes a wavelength filter and / or a wavelength-selective polarizer. The visualization arrangement (1) according to claim 1 or 2, characterized in that

10. The lighting device (4) is designed to emit two-color light. The visualization arrangement (1) according to claim 1 or 2, characterized in that

11. The illumination device (4) is designed to emit multicolor light, and the polarization filtering device (20) located downstream of the illumination device (4) and upstream of the object space region (5) in the beam path (6) includes at least one notch filter and / or many bandpass filters. The visualization arrangement (1) according to claim 1 or 2, characterized in that

12. The visualization arrangement (1) according to claim 1 or 2, characterized by at least one beam splitter (12) positioned in the beam path (6) between the object space region (5) and the video cameras (2, 3).

13. A visualization configuration (1) for microsurgery, comprising an imaging device (14), an illumination device (4), and a polarization determination configuration, The polarization determination configuration includes two polarization cameras (17) to which each of the two polarization cameras (17) is assigned an individual partial beam path of the beam path (6), and an evaluation device (13). The evaluation device (13) is designed to generate an image representation having polarization contrast using an image captured by the polarization camera (17), and to display the image representation using the imaging device (14). The evaluation device (13) is designed to display the generated image representation having polarization contrast by overlaying it with the white light image representation captured by the two polarizing cameras (17) using the imaging device (14). A visualization arrangement (1) characterized by the following.

14. A method for generating an image having polarization contrast of an object (5) by a visualization arrangement (1) for microsurgery as described in claim 1, - Step (41) of irradiating the object (5) with light waves using the illumination device (4), - A step (42) of capturing the light waves emitted from the object (5) after the interaction between the irradiated light waves and the object (5) using at least three video cameras (2, 3) or at least two polarizing cameras (17), - A step (43) of generating an image representation having polarization contrast based on the polarization state generated of the irradiated light wave and / or the polarization state analyzed of the captured light wave. A method characterized by including

15. The illumination device (4) and the polarization filtering device (20) positioned downstream of the illumination device (4) and upstream of the object (5) in the beam path (6) irradiate light waves with a defined polarization state. The method according to claim 14, characterized in that

16. The polarization state of the captured light wave is analyzed by the polarization filtering devices (21-24) located in the beam path (6) upstream of the video cameras (2, 3), and / or by the polarization camera (17). The method according to claim 14 or 15, characterized in that

17. The evaluation device (13) is used to generate an image representation having polarization contrast based on the analyzed polarization state of the captured light wave, the set of Müller matrix coefficients is determined by the image captured by the video cameras (2, 3) and / or the polarization camera (17), and the polarization contrast derived from the coefficients is determined. The method according to claim 14 or 15, characterized in that

18. The image representation having polarization contrast is generated within a time interval of less than 50 ms, and / or the resolution of the generated stereoscopic image representation having polarization contrast is less than 10% different from the resolution of the corresponding image representation without polarization contrast. The method according to claim 14 or 15, characterized in that

19. The image representation having polarization contrast is generated within a time interval of less than 50 ms and displayed overlaid on the multicolor image representation. The method according to claim 18, characterized in that

20. A microscope comprising the visualization arrangement (1) described in claim 1, 2, or 13, or designed to perform the method described in claim 14.

Images