Visualisation arrangement for microsurgery

Abstract

The invention relates to a visualization arrangement (1) for microsurgery, comprising an imaging device (14), an illumination device (4) and a polarization determination arrangement. The polarization determination arrangement comprises at least two video cameras (2) and at least one further video camera (3), which are designed to capture light waves of a plurality of light wavelengths in the visible light wavelength range, wherein each of the three video cameras (2, 3) is assigned a separate partial beam path in the beam path (6), a plurality of polarization filters (20 to 24), and an evaluation device (13), wherein at least one polarization filter (21 to 24) is arranged upstream of three video cameras of the at least three video cameras (2, 3) in each beam path (6), wherein the polarization filters (20 to 24) are set or settable such that the polarization effects of the polarization filters (20 to 24) arranged upstream of the specified at least one further video camera (3) and of at least one of the aforementioned video cameras (2) designed to capture light waves of a plurality of light wavelengths in the visible light wavelength range differ from one another in the beam path (6), wherein the evaluation device (13) is designed to create an image representation with polarization contrast using the images captured by the video cameras (2, 3) and to display said image representation by means of the imaging device (14).

Description

Technical Field

[0001] This invention relates to a visualization arrangement for microsurgical procedures (e.g., for a surgical microscope), the arrangement having imaging means for creating an image representation with polarization contrast, such as a stereoscopic imaging means for creating a stereoscopic image representation with polarization contrast. The invention also relates to a method for creating an image representation with polarization contrast (e.g., a stereoscopic image representation with polarization contrast) of an object to be imaged using a visualization arrangement for microsurgical procedures. Furthermore, the invention relates to a microscope, such as a surgical microscope. Background Technology

[0002] Surgical microscopes are used in microsurgical procedures across various disciplines, primarily in neurosurgery, spinal surgery, otolaryngology, and ophthalmic surgery. A key advantage of surgical microscopes is their large working distance (200 mm to 600 mm) and moderate magnification (up to approximately 20x) for stereoscopic imaging. These features allow for the use of surgical instruments in a sterile surgical environment while obtaining a stereoscopic view of the surgical site. In recent years, analog systems have been transitioning to digital systems. Digital systems utilize cameras and 3D monitors or other 3D reconstruction systems (head-mounted displays (HMDs), digital eyepieces (binocular eyepiece monitors (cantilevered))) for image recording and representation.

[0003] A key driver in the development of surgical microscopes is user expectations regarding tissue differentiation. Depending on the discipline and application, tissue differentiation can manifest as distinguishing tumors from healthy tissue, differentiating white matter from gray matter in the brain, improving vascular and neural representations, visualizing phase objects (lens, capsular bag, etc.) in cataract surgery, or visualizing membranes during retinal surgery. Digital surgical microscopes offer significant advantages in improving tissue differentiation because the camera systems used can be tailored for this purpose.

[0004] From the user's perspective, the following requirements for tissue differentiation techniques emerge, particularly in the field of neurosurgery. (i) For stereoscopic image data, various tissue types must be differentiated in real time, i.e., without significant time delay for the user (e.g., the surgeon). For digital systems, this time is approximately < 50 ms. (ii) Tissues must be differentiated across the entire surgical site, typically with a diameter of approximately 10 mm to 50 mm. The resolution of tissue differentiation should correspond to the resolution of the stereoscopic image data (analog or digital), but may be lower. (iii) Surgeons should be able to visually interpret tissue differentiation, and its applicability should be supported by clinical research. (iv) Tissue differentiation should be able to be turned on and off as needed. (v) The techniques used for tissue differentiation should not significantly increase costs, and in particular, should not significantly increase the size of the surgical microscope. (vi) Ideally, tissues should be differentiated without the use of markers and dyes, as these require lengthy approval processes and often cause side effects for patients.

[0005] Scientific literature has disclosed a wealth of techniques that can be used for tissue differentiation. In this context, optical techniques offer numerous advantages over non-optical methods (such as ultrasound) due to their good integrability and non-contact measurement capabilities. The most important optical techniques for tissue differentiation include the detection of fluorescence / autofluorescence (continuous and / or time-resolved detection), laser Doppler and laser speckle imaging, optical coherence tomography (OCT), (coherent or incoherent) Raman spectroscopy, narrowband imaging, and the detection of the effects of biological tissue on the polarization state of light. Despite a large body of scientific publications, only a small number of these techniques have been implemented in products; this is due to the difficulty in meeting the aforementioned requirements.

[0006] Therefore, camera-based fluorescence techniques, in particular, have been established in both surgical microscopes and endoscopes in recent years because they best meet the aforementioned requirements. Currently, camera-based fluorescence techniques rely on three medically approved dyes: ICG, NAF, and 5-ALA. Applicably, these dyes are used to distinguish between tumors and non-tumors and to visualize blood flow. The aforementioned fluorescence techniques using these three approved dyes meet requirements (i) to (v), but not requirement (vi), namely, they can only be used in combination with pharmaceutical agents. Another drawback of the aforementioned fluorescence options is their inability to distinguish all applicable tissue types. Some types of tumors do not absorb the aforementioned dyes. Furthermore, in neurosurgery, protecting brain function during surgery is crucial. For this purpose, it is necessary to identify brain fiber tracts (white matter) and differentiate them from tumors or cortical gray matter. Currently, none of the aforementioned dyes can do this. Therefore, techniques to differentiate tumor tissue, blood vessels, and white and gray matter are highly needed, especially in neurosurgery.

[0007] Among the aforementioned techniques, polarization is advantageous because it can differentiate tissues without the need for dyes or reagents and exhibits sensitivity to different tissue types due to underlying physical processes. At the cellular level, tumors are disordered structures, while fiber bundles specifically represent strongly ordered regions. Literature indicates that such structures exhibit varying results regarding their influence on the polarization of input radiant light.

[0008] The following sections describe in detail the formal system of Stokes vectors and Mueller matrices to describe the interaction between optical elements and tissues in surgical sites and partially polarized light. The Mueller matrix is ​​a 4 × 4 transformation matrix of the Stokes vector of the illuminating light, which, after multiplication, provides the Stokes vector at the detector location. Therefore, understanding the Mueller matrix and its 16 elements contains all the information about how the object acts on partially polarized light. In metrology, many polarimeters can measure the complete Mueller matrix at a single point or over a region (e.g., https: / / mountainphotonics.de / product / axo-axostep / ). A Mueller polarimeter consists of a light source, a PSG (polarization state generator), a PSA (polarization state analyzer), and a (single-point or regional) detector. In this case, the PSG and PSA can be implemented in different ways, for example, by rotating delay elements or statically by ferroelectric elements.For general background on this field, please refer to the following publications: W. Singer, M. Totzeck, H. Gross, Handbook of Optical Systems, Volume 2, "Physical ImageFormation", Section 26.2.9, page 475 and following pages of the "Handbook of Optical Systems" series, H. Gross (ed.), Wiley VCH [1]; H. Engstrom, "Coherency matrix polarization measurements: application to magnetoopticgarnet films", Appl. Opt. 30 (1991) 1730-1734 [4]; A. Pigula, N.T. Clancy, S. Arya, GB. Hanna, D.S. Elson: Video-rate dual polarization multispectral endoscopic imaging, International Society for Optics and Photonics [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 Biomedical Imaging”, Photonics 2019, 6, 34; doi:10.3390 / photonics6010034 [6].

[0009] The following explains how to determine polarization contrast from the Stokes vector, particularly the polarization contrast of the tissue to be examined. The Stokes vector is a conventional method used in polarization optics to represent partial polarization states [1]. The Stokes vector consists of four real components, known as the “Stokes parameters,” the values ​​of which can be determined by measuring the transmittance of light through a particular polarizer.

[0010] (1)

[0011] in this case, This represents the total intensity (i.e., the transmittance of the neutral element). This represents the transmittance through a 0° linear polarizer. This indicates the transmittance through a 45° linear polarizer. This represents the transmittance through a 90° linear polarizer. This indicates the transmittance through a 135° linear polarizer. This represents the transmittance through a right-handed circular polarizer, and This indicates the transmittance through a left-handed circular polarizer.

[0012] Therefore, Stokes parameters It indicates the intensity of light. Specifies how much difference there is between the component of light that is linearly polarized in the x-direction and the component of light that is linearly polarized in the y-direction (i.e., the component that is linearly polarized horizontally and the component that is linearly polarized vertically, respectively). Specifies how much difference there is between the component of light that is linearly polarized at 45° and the component that is linearly polarized at 135° (i.e., the component that is linearly polarized diagonally). This specifies the difference between the right-hand circularly polarized component of light and the left-hand circularly polarized component (i.e., the circularly polarized component).

[0013] The degree of polarization is an important characteristic parameter of light in tissue contrast. The degree of polarization is the component of polarized light in the total intensity, and can be calculated according to formula (1) using the following equation:

[0014] (2)

[0015] For polarized irradiation, the degree of polarization typically decreases due to interaction with the tissue, particularly due to multiple reflections. Since these structures often have a linear form (e.g., nerve fiber bundles), the degree of linear polarization is also low. Specially related

[0016] (3)

[0017] Similarly, circular polarization degree for

[0018] (4)

[0019] The following explains the principle of measuring the Stokes vector. Although six different polarizers and measurements of the total intensity affect the definition of the Stokes vector, four polarizers are sufficient to definitively measure the Stokes parameter. This is due to the fact that the sum of any two orthogonal polarization states already represents the total intensity, i.e.

[0020] (5)

[0021] Therefore, the Stokes vector (1) can also be written as follows:

[0022] (6)

[0023] That is, the Stokes vector is derived from polarization measurements. , , and A unique definition is given.

[0024] The following explains the Mueller matrix and its informational content, particularly for organizations. The polarization effect on an object (such as an organization) involves transforming the incident Stokes vector into the outgoing Stokes vector. In a linear scheme, this transformation is described by multiplication with a 4 × 4 matrix (i.e., the Mueller matrix):

[0025] (7)

[0026] The Mueller matrix is...

[0027] (8)

[0028] Individually, each element of the Mueller matrix has a simple meaning. Each element describes the component excited by one Stokes parameter by another. Therefore, for example, express quilt excitation.

[0029] As described in the literature, for example in [2], decomposing the Mueller matrix into fundamental polarization matrices is important for describing the polarization of tissues. For example, one such decomposition is the Lu-Chipman polarization decomposition, where the Mueller matrix is ​​represented by the product of the depolarized Mueller matrix, the delayed Mueller matrix, and the dichroic Mueller matrix:

[0030] (9)

[0031] The depolarization Mueller matrix is:

[0032] (10)

[0033] The delayed Mueller matrix is

[0034] (11)

[0035] in, This represents a 3-component zero vector, and and This represents a 3 × 3 submatrix representing the linear and circular delays. The submatrix of a linear delay plate depends on two parameters: the absolute value of the delay and the orientation, i.e., the position of one of the two eigenpolarities. A circular delay plate depends only on the absolute value of the circular delay. Therefore, It is uniquely described by only 3 scalar parameters. According to [2], the delay value is derived as follows:

[0036] (12)

[0037] as well as

[0038] (13)

[0039] And the dichroic Mueller matrix is

[0040] (14)

[0041] Where the dichroism vector is

[0042] (15)

[0043] And the submatrix is

[0044] (16)

[0045] Where I represents a 3 × 3 identity matrix.

[0046] Besides this known decomposition, a number of other decompositions exist in the polarization determination literature that decompose the Mueller matrix into functions of elementary matrices [2]. The decomposition provides a physically unique and correct representation of the Mueller matrix consisting of depolarization, retardation, and dichroism. However, the correct execution of the decomposition also requires the measurement of the entire Mueller matrix. If this is the case, the Mueller matrix decomposition is the preferred form of analysis.

[0047] However, polarizers are generally not perfect and must be redescribed by the Mueller matrix. However, this can be taken into account during the measurement process, as shown in [4] and described below. At the stage of measuring the Stokes vector, it should be taken into account that the existing components are not ideal from the perspective of polarization optics. However, it can be assumed that these components will not depolarize. Therefore, the effect of these components on partially polarized light is described by a known but not necessarily simple Jones matrix. For example, a polarizer can only achieve a polarization degree of 0.9. It is obviously more reasonable to take this characteristic into account during the evaluation rather than including it in the error budget. According to [4], a general method for measuring the Stokes vector (or polarization matrix) can be established that only assumes that the Jones matrix of the polarization modification component is known, but does not assume that the Jones matrix of these components has a specific value. The basis of this method is the linearity of the polarization matrix transformation in the Jones matrix.

[0048]

[0049] Among them, P in and P out Let represent the input polarization matrix and the output polarization matrix, and L represent the Jones matrix of the measurement system. This relationship is expressed in P. in The intensity is linear, and this property remains unchanged when transitioning to intensity.

[0050]

[0051] Using four different L values ​​for four strength measurements allows for the establishment of a system of linear equations and the determination of P. in ,

[0052]

[0053] Among them, P k Let P1 to P4 represent the real parts of the polarization matrix. When represented in matrix form, the solution is obtained by inverting the coefficient matrix.

[0054]

[0055] To determine the coefficient A jk I must be j The equation is expanded and calculated.

[0056]

[0057] Therefore, the elements of the coefficient matrix are obtained as follows:

[0058]

[0059] For practical measurements, four different Jones matrices of the measured quantity must be realized using polarization optics. Several options are available for this purpose. [4] specifies a standard method using linear polarizers at 0°, 45°, and 90°, and a quarter-wave plate with a slow axis of 90° followed by a 45° polarizer. Alternative measurement methods use a rotated quarter-wave plate followed by a polarizer. Of course, even more configurations can be conceived. In the case of a “good” measurement method, the accuracy of the measurement no longer depends on how well the components maintain predetermined values ​​(e.g., delay, extinction ratio), but only on how well those values ​​are known. Another important variable affecting the accuracy of the measurement is whether these components can span an orthonormal basis for the Jones vectors. In this case, the relative error of the Stokes vector components is directly introduced into the Mueller matrix. However, given the accuracy 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 will be.

[0060] DE 10 2017 100 904 A1 describes an image conversion module for a microscope designed for polarization measurement using a polarization mask. DE 102 42 983 A1, CN 107490851 A, DE 102018 110 806 A1, and WO 2016 170 816 A1 describe surgical microscopes designed to achieve at least partial polarization determination.

[0061] The most significant challenges in integrating a complete Mueller polarimeter into a surgical microscope, or generally into a microscope requiring real-time evaluation, are the following requirements: (i) real-time processing capability; (ii) stereoscopic observation; and (v) limited installation space and low cost (see above). For this reason, surgical microscopes have so far only implemented simple cross-linear polarizers related to illumination and observation (see below). Various methods for achieving the aforementioned requirements with polarimeters have been described in the literature, but none have been successful to date.

[0062] The ZEISS EXTARO surgical microscope (https: / / www.zeiss.de / meditec / produkte / zahnheilkunde / operationsmikroskope / extaro-300.html) specifically utilizes linear polarizers. A first polarizer is mounted to pivot in and out of the microscope's beam path, and two additional polarizers are integrated into two three-dimensional beam paths to similarly pivot in and out of beams perpendicular to the polarizers. Polarizers can be used to suppress reflections from the tooth surface ("glare-free mode").

[0063] In J. Qi, DS Elson, Mueller polarimetric imaging for surgical and diagnostic application, J. Biophotonics 10, 950–982 (2017) / DOI 10.1002 / jbio.201600152[2], in Figure 8 In the "3 × 3 Mueller polarization determination endoscope," a linear polarizer is fixedly positioned upstream of the illumination exit at the distal end of the endoscope. During the measurement procedure, the endoscope rotates around the optical axis and is fixedly aligned to three different positions. Therefore, three different alignments of linear polarization can be achieved during illumination. A filter wheel integrating three different polarizers is attached in front of the camera in the observed beam path. This endoscope can be used to determine the 3 × 3 sub-matrix of the Mueller matrix. The measurement duration is 11.6 s. Rotating the endoscope during clinical use is practically impractical.

[0064] Furthermore, [2] describes an endoscope for measuring the complete Mueller matrix, which has a rotational PSG and a temporal PSA, with a measurement duration of 30 s (see [link to article]). Figure 10 Due to the long measurement duration and the use of rotating elements, this endoscope is unsuitable for clinical use or for any application requiring real-time assessment. [2] A stereoscopic endoscope with a linear polarizer covering the illumination and a stereoscopic channel at the distal end is also described. The second stereoscopic channel measures the polarization perpendicular to it (see Figure 11 Additionally, polarization measurements are combined with narrowband spectral imaging. This endoscope meets the requirements of real-time processing capabilities and small installation space / low cost, but it cannot create stereoscopic images for users (e.g., surgeons). Furthermore, only a very small portion (2 × 2 submatrix) of the Mueller matrix can be determined, thus failing to obtain the necessary information about sample characteristics.

[0065] In Vizet, J., Rehbinder, J., Deby, S. et al., In vivo imaging of uterinecervix with a Mueller polarimetric colposcope, Sci Rep 7, 2471 (2017), https: / / doi.org / 10.1038 / s41598-017-02645-9 [3], a “Mueller polarimetric colposcope” with a PSG and PSA based on a ferroelectric modulator is described. The module is fixed below the colposcope and can pivot in and out. The measurement duration is about 1.6 s; the entire 4 × 4 Mueller matrix is ​​measured. In terms of optical structure, the colposcope corresponds to the surgical microscope. In this case, the polarimeter module is attached below the main objective and has a single-view beam path. For this reason, the method does not achieve real-time processing capability, stereoscopic observation, compact structure and low cost.

[0066] Achieving three-dimensional tissue differentiation in real time (< 50 ms) and over a large observation field (> 1 cm diameter) goes beyond the capabilities of simply using cross polarizers, and no known technique has been able to do so to date. Summary of the Invention

[0067] In light of the described background, the problem to be solved by the present invention is to provide an advantageous visualization arrangement for microsurgery, an advantageous method for creating an image representation with polarization contrast by means of a visualization arrangement for microsurgery, and a microscope (particularly a surgical microscope).

[0068] The aforementioned problems are addressed by a visualization arrangement for microsurgery as described below, a method for creating an image representation with polarization contrast using the visualization arrangement for microsurgery as described below, and a microscope as described below. Other advantageous configurations of the invention are contained herein.

[0069] The visualization arrangement 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 arrangement. The polarization determination arrangement includes: at least two video cameras and at least one additional video camera, preferably two additional video cameras, which are designed to capture light waves of multiple wavelengths within the visible light wavelength range (i.e., in the wavelength range between 400 nm and 780 nm); multiple polarization filtering devices; and an evaluation device. Each of the three aforementioned video cameras is assigned a separate portion of the beam path. Therefore, the three aforementioned video cameras can be arranged adjacent to each other in the beam path, or in other words, parallel to each other in terms of beam paths. In this context, this does not necessarily mean a spatially or geometrically parallel arrangement or a spatially adjacent arrangement, but rather an arrangement that allows each video camera to capture light waves independently in different portions of the beam path.

[0070] For example, at least two video cameras used to capture multicolor visible light are RGB cameras. For example, the at least one additional video camera could be a fluorescence camera.

[0071] At least one polarizing filter is arranged in the beam path upstream of each of the three video cameras (e.g., upstream of each of the three aforementioned video cameras). Optionally, at least one polarizing filter may be arranged in the beam path downstream of the illumination device and upstream of the object space region (e.g., the object or object plane to be imaged). These polarizing filters are configured, or may be configured, such that the polarization effects of the polarizing filters arranged upstream of at least one designated additional video camera and upstream of at least one of the aforementioned video cameras designed to capture light waves of multiple wavelengths in the visible light wavelength range are different from each other. Thus, at least two, preferably three, polarizing filters are arranged, or may be arranged, upstream of the video cameras in a manner deviating from each other. For example, the polarizing filters may also be configured, or may be configured, such that the polarization effects of the three polarizing filters arranged upstream of the three aforementioned video cameras in the beam path are different from each other, i.e., such that each of the three aforementioned video cameras receives light simultaneously with the other two video cameras, but the received light differs in polarization from the light received by the other video cameras.

[0072] In this case, the object to be imaged should also be understood as the subject or a portion of the subject, such as human, animal, or plant tissue.

[0073] The evaluation apparatus is designed to create an image representation with polarization contrast (e.g., a two-dimensional or three-dimensional image representation) using images captured by a video camera and to display (preferably, stereoscopically) the image representation by means of an imaging device. During this process, the created image representation with polarization contrast can be overlaid on the beam path of the imaging device. The created image representation with polarization contrast can be overlaid on an image representation without polarization contrast in a partially transparent manner. Therefore, the created image representation with polarization contrast can be overlaid and masked. Polarization filters can be turned on and off during this process.

[0074] In an advantageous variant, the evaluation apparatus is designed to display, by means of an imaging device, a created image representation with polarization contrast superimposed on a white light image representation captured by at least two video cameras designed to capture light waves of multiple wavelengths within the visible light wavelength range. The at least two video cameras can be the aforementioned at least two video cameras. However, more than three of the aforementioned video cameras may also be present. In particular, it is possible that no polarization filter is arranged, or at least not sequentially arranged, in front of at least one of the video cameras used to capture multicolor visible light. In this way, a high-resolution multicolor image representation can be created by means of at least one of the video cameras used to capture multicolor visible light, and the created image representation with polarization contrast can be superimposed on the high-resolution multicolor image representation. For example, the polarization filter in front of at least one of the video cameras used to capture multicolor visible light can be switchable, such that the image representation is captured alternately (preferably at intervals of less than 100 ms, particularly less than 40 ms) with and without an upstream polarization filter. Therefore, a high-resolution image representation of the object to be imaged with polarization contrast and a high-resolution image representation without polarization contrast can be captured using the same video camera. Alternatively, at least one additional video camera may be present, wherein at least one video camera is designed to capture a multicolor image representation of the object to be imaged without polarization contrast. The image representation with polarization contrast can be displayed in a manner that overlays the captured image representation.

[0075] For example, white light can be understood as light with a broadband color spectrum. In this case, the wavelengths can essentially fall within the visible light range. The wavelength distribution is usually continuous. The human perception of white light is due to the broadband color spectrum of the "white light source."

[0076] In this case, the color impression produced in the eye is correlated. Therefore, this is a physiological effect rather than a physical one. That is, the impression of white can be based on different spectra limited to the visible light range.

[0077] The visualization setup can be configured as a visualization setup for microsurgical equipment, such as a surgical microscope, particularly a surgical microscope designed for neurosurgery. The visualization setup preferably has a fully digital configuration.

[0078] If the visualization arrangement is configured as a component of a microscope, the microscope can be configured as a fully digital microscope, particularly a fully digital surgical microscope. The visualization arrangement can be designed to record and display white light video data and / or fluorescence video data in real-time stereoscopically, particularly displaying the data superimposed with a created image representation with polarization contrast. In applications as a component of a surgical microscope, the surgical microscope can preferably be designed for neurosurgical procedures. The range or diameter of the object surface or object plane of the surgical microscope can be between 10 mm and 50 mm. Preferably, the resolution of the created image representation with polarization contrast is lower than the resolution of a (stereoscopic) image representation without polarization contrast displayed by means of a (stereoscopic) imaging device, or their resolutions correspond to each other. For example, the aforementioned resolutions can differ from each other by less than 10%.

[0079] In another variant, the known meaning of the polarization contrast can be appropriately stored for a specific application and can be turned on and off as a display. For example, in the case of neurosurgical applications, tissue types imaged at polarization resolution or tissue features that can be deduced from polarization-resolved image representations can be displayed. For this purpose, complete Mueller matrices for various tissue types can be determined in clinical studies. For various tissue types, clinically relevant elements or elements generally relevant to the corresponding application can be deduced from the analysis of the Mueller matrices. Within the scope of the visualization setup used, such as within a microscope, only relevant elements of the Mueller 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, simplified Mueller matrix.

[0080] The advantages of the visualization arrangement according to the invention lie in its provision of an integrated polarization measurement technique that meets the requirements of real-time processing capability, small installation space, low cost, and optional stereoscopic observation. In variations of the visualization arrangement for surgical microscopes, the invention allows for improved tissue differentiation, particularly in the field of neurosurgery. With the visualization arrangement according to the invention, data can be simultaneously captured that allows for the determination of Stokes vectors crucial to the respective applications, as well as the complete Mueller matrix or Mueller matrix elements or Mueller matrix coefficients.

[0081] In an advantageous variant, at least one (e.g., at least three, or four) polarizing filter devices arranged upstream of three, for example four video cameras, preferably all of the aforementioned polarizing filter devices, comprises a variety of polarizers that are different from each other, for example, at least four different polarizers. At least one of the polarizing filter devices may include a filter wheel for switching between the various polarizers. Thus, corresponding polarizers from the various polarizers can be introduced into the beam path. For example, at least one of the polarizing filter devices may include at least three, particularly four, linear polarizers and optionally at least one circular polarizer. For this purpose, at least one of the polarizing filter devices may include one or more retardation elements and / or at least variable retardation plates and / or ferroelectric elements, etc.

[0082] In an advantageous configuration with four cameras, i.e., with appropriate selection of polarizers for each polarizing filter introduced into the beam path, at least three, preferably all four, of the four polarizers arranged upstream of the video camera exhibit different polarization effects from each other. For example, three of the polarizers may be linear polarizers, such as those selected... Figure 3 The P0, P45, P90, and P135 polarizers shown are provided, and one polarizer can be a circular polarizer, or three or four polarizers can be linear polarizers. Filters with the same polarization effect can be arranged or positioned upstream of a video camera designed to capture light waves of multiple wavelengths within the visible light wavelength range. Preferably, the polarization effect of the aforementioned filters is orthogonal to the polarization effect of polarizers optionally arranged downstream of the illumination device and upstream of the object to be imaged.

[0083] In advantageous variations, at least one, for example two, of the additional video cameras is designed to capture monochromatic light (i.e., light at or within a defined wavelength range, particularly fluorescence). In this case, the captureable wavelength range may also be outside the visible light wavelength range.

[0084] In another variant, at least one of the aforementioned video cameras (e.g., three of the aforementioned video cameras) may take the form of a polarizing camera. For example, a polarizing camera may include four linear polarizers at the pixel level. A polarizing camera may also include at least one circular polarizer at the pixel level, for example, instead of one of the four linear polarizers, i.e., including three linear polarizers and one circular polarizer. A polarizing filter arranged upstream of a video camera that does not take the form of a polarizing camera (i.e., upstream of a video camera designed to capture light waves of multiple wavelengths in the visible light wavelength range) may include or be configured as a circular polarizer. This can be implemented as a combination of linear polarizers and delay plates (e.g., a zero-degree quarter-wave plate element).

[0085] The evaluation apparatus is advantageously designed to determine, in particular a finite set, of Mueller matrix coefficients by means of images captured by a video camera, and to determine, for example, calculate, the polarization contrast derived from these coefficients.

[0086] In a particularly advantageous configuration, a polarization filter, 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 biased wavelengths (e.g., two defined, mutually biased wavelength ranges) in a mutually biased manner. This allows for the simultaneous acquisition of a relatively large amount of data, by which a relatively large number of Mueller matrix coefficients can be determined or ascertained. Consequently, a stronger polarization contrast can be determined, resulting in a high-quality image representation with polarization contrast. Furthermore, simultaneously usable detection channels (e.g., multiple camera sensors in an RGB camera), optionally spectrally encoded detection channels, can be used for different polarization information about the object to be examined. Polarization and spectrum can therefore be designed such that multiple detection channels (e.g., each detection channel) provide different information, such as different tissue information.

[0087] At least one of the polarization filtering devices may include a color filter or a wavelength filter and / or a wavelength-selective or wavelength-specific polarizer. In particular, it can be used to implement the above configuration. The corresponding polarization filtering device may, for example, include a notch filter, particularly a polarizing notch filter and / or a bandpass filter, particularly a polarizing bandpass filter.

[0088] Generally, the aforementioned polarization filtering device 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 configured.

[0089] The illumination device can be designed to emit dual-color or multi-color light. Preferably, the illumination device is designed to emit multi-color light, and the polarization filtering device arranged downstream of the illumination device and upstream of the object space region in the beam path includes at least one (e.g., two) notch filters, preferably polarizing notch filters and / or at least one (e.g., two) bandpass filters, preferably polarizing bandpass filters.

[0090] Furthermore, the visualization arrangement may include at least one beam splitter, such as a dichroic beam splitter. The beam splitter may be positioned in the beam path between the object space region and the video camera.

[0091] At least one of the video cameras designed to capture or receive light waves of multiple wavelengths in the visible light wavelength range can be configured as a 3-chip camera or a 1-chip camera.

[0092] A visualization arrangement for microsurgery according to the invention, as an alternative to the aforementioned visualization arrangement, includes an imaging device (e.g., a stereoscopic imaging device), an illumination device, and a polarization determination arrangement. The polarization determination arrangement includes two polarization cameras and an evaluation device, wherein each of the two polarization cameras is assigned a separate portion of the beam path in the beam path. The evaluation device is designed to create an image representation with polarization contrast using images captured by the polarization cameras, and to display (preferably stereoscopically) the image representation by means of the imaging device. The solution provided by the alternative visualization arrangement according to the invention is equivalent to the solution of the visualization arrangement described above according to the invention. Both variations use the same technical effect to create an image representation with polarization contrast and have the same features and advantages, which have been described in detail above. In particular, the alternative visualization arrangement according to the invention may include the aforementioned features and characteristics, which are optional in the context of the visualization arrangement according to the invention described first.

[0093] The evaluation device is designed to display the created image representation with polarization contrast, superimposed on a white light image representation captured by two polarization cameras. In this case, the display is implemented using an imaging device.

[0094] The method according to the invention for creating an image representation of an object with polarization contrast (e.g., a stereoscopic image representation with polarization contrast) by means of the above-described visualization arrangement for microsurgery (particularly for surgical microscopes) according to the invention comprises the following steps: irradiating the object with light waves (particularly in the visible light wavelength range and optionally beyond the visible light wavelength range) by means of an irradiation device; capturing or receiving light waves emitted by the object after the object interacts with the irradiated light waves by means of at least two polarization cameras or at least three video cameras; and creating an image representation with polarization contrast (preferably a stereoscopic image representation with polarization contrast) 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 invention has the features and advantages of the visualization arrangement according to the invention already described.

[0095] In an advantageous variant, light waves in a defined polarization state are radiated by means of an illumination device and a polarization filter arranged downstream of the illumination device and upstream of the object in the beam path. The polarization state of the received light waves can be analyzed by means of the aforementioned video camera and the polarization filter arranged upstream of the video camera in the beam path. An evaluation device can be used to create an image representation (e.g., a stereoscopic image representation) with polarization contrast based on the analyzed polarization state of the captured or received light waves, wherein the set of Mueller matrix coefficients is determined by means of images captured by the video camera and / or polarization camera, and the polarization contrast derived from said coefficients is determined, and in particular calculated.

[0096] The image representation with polarization contrast (e.g., a stereoscopic image representation) is preferably created within a time interval of less than 50 ms. The resolution deviation between the created image representation with polarization contrast (e.g., a stereoscopic image representation) and the corresponding image representation without polarization contrast (e.g., a stereoscopic image representation) is preferably less than 10%. Particularly preferably, the image representation with polarization contrast (e.g., a stereoscopic image representation) is created within a time interval of less than 50 ms and displayed in a manner superimposed on the multicolor image representation (e.g., a stereoscopic image representation).

[0097] Within the scope of the method according to the invention, photogrammetry can be applied to video signals to identify corresponding pixels in, for example, stereo channels for polarization determination evaluation. In this process, values ​​reflecting polarization characteristics can be calculated pixel-by-pixel. Thus, color values ​​reflecting polarization characteristics can be derived pixel-by-pixel. In particular, a stereo representation with polarization characteristics can be presented in real time, either alone or superimposed on a white light image.

[0098] The microscope according to the invention can be a surgical microscope (e.g., a neurosurgical microscope) that includes the visualization arrangement described above according to the invention and / or is designed to perform the methods described above according to the invention. The microscope has the features and advantages already specified above. The microscope according to the invention is preferably configured stereoscopically and / or partially or fully digitally.

[0099] Microscopes (especially surgical microscopes) may include a focal length variable optical element unit (i.e., a focus variable optical element unit (zoom lens)), and / or at least one objective lens arranged upstream of at least one video camera in the beam path, and / or at least one zoom optical element unit and / or an ambient camera (i.e., a video camera for capturing the spatial area around the object area to be imaged by the microscope).

[0100] The invention will now be explained in more detail with reference to the accompanying drawings and exemplary embodiments. Although the invention has been described and illustrated in more detail with the aid of preferred exemplary embodiments, the invention is not limited to the disclosed examples, and other variations can be derived from the invention by those skilled in the art without departing from the scope of protection of the invention.

[0101] These figures are not necessarily drawn to scale in every detail, and may be presented in enlarged or reduced form for clarity. Therefore, the functional details disclosed herein should not be construed as limiting, but merely as an illustrative basis to provide guidance for those skilled in the art to use the invention in various ways.

[0102] When used in a series of two or more elements, the expression “and / or” as used herein means that any of the listed elements may be used alone, or any combination of two or more of the listed elements may be used. For example, if a structure is described as containing parts A, B, and / or C, then the structure may contain: A alone; B alone; C alone; A and B together; A and C together; B and C together; or A, B, and C together. Attached Figure Description

[0103] Figure 1 A surgical microscope according to the invention is schematically shown in block diagram form, the surgical microscope having a visualization arrangement according to the invention.

[0104] Figure 2 The polarization optical operation mode according to the present invention is schematically illustrated in the form of a block diagram.

[0105] Figure 3 An exemplary polarizing filter is shown schematically.

[0106] Figure 4 The polarization optical operation mode of an exemplary variant of the visual arrangement according to the invention is schematically illustrated in the form of a block diagram.

[0107] Figure 5 The polarization optical operation mode of an exemplary variant of the visual arrangement according to the invention is schematically illustrated in the form of a block diagram.

[0108] Figure 6 The polarization optical operation mode of an exemplary variant of the visual arrangement according to the invention is schematically illustrated in the form of a block diagram.

[0109] Figure 7 The polarization optical operation mode of an exemplary variant of the visual arrangement according to the invention is schematically illustrated in the form of a block diagram.

[0110] Figure 8The polarization optical operation mode of an exemplary variant of the visual arrangement according to the invention is schematically illustrated in the form of a block diagram.

[0111] Figure 9 The principle of a polarization camera is illustrated schematically.

[0112] Figure 10 Two diagrams schematically illustrate the possible illumination of an object region.

[0113] Figure 11 This schematically illustrates how to achieve, with the aid of a polarizing notch filter, such as Figure 10 The lower part of the diagram shows the illumination pattern.

[0114] Figure 12 This schematically illustrates the use of a polarizing bandpass filter to achieve... Figure 11 The variant shown.

[0115] Figure 13 The diagram schematically illustrates, in the form of a block diagram, an exemplary variant of polarization optics operation using two different wavelengths in a visual arrangement according to the invention.

[0116] Figure 14 The diagram schematically illustrates, in the form of a block diagram, an exemplary variant of the polarization optics operation mode using two different wavelengths and two polarization cameras according to the present invention.

[0117] Figure 15 The diagram schematically illustrates, in the form of a block diagram, an exemplary variant of polarization optics operation using two different wavelengths in a visual arrangement according to the invention.

[0118] Figure 16 The spectral resolution of the prism and filter is schematically shown.

[0119] Figure 17 The method according to the invention is illustrated schematically in the form of a flowchart. Detailed Implementation

[0120] Figure 1 A surgical microscope 1 according to the present invention is schematically illustrated in block diagram form. For example, the surgical microscope 1 can be designed for application in neurosurgical and spinal surgery procedures. The surgical microscope 1 includes a visualization arrangement having an illumination device 4, an object plane or object space region 5, a stereoscopic imaging device, and a polarization determination arrangement in which an object, for example, to be imaged in a magnified manner, can be arranged. The illumination device 4 is designed to illuminate the object space region 5 (i.e., radiate light waves onto the object). The beam path is indicated by an arrow with reference numeral 6.

[0121] Preferably, microscope 1 is in the form of a fully digital microscope. This microscope is preferably designed to record and display both white light video data and fluorescence video data in real-time stereoscopically. This is achieved by using, in each case, two video cameras 2 (VIS cameras, such as RGB cameras) designed to capture light waves of multiple wavelengths within the visible light wavelength range, and at least one additional video camera 3 (preferably, two additional video cameras 3 as shown), configured as monochrome cameras to improve sensitivity and designed to capture fluorescence (fluorescence camera). The two VIS cameras 2 are preferably 3-chip cameras or 1-chip cameras. The fluorescence camera 3 can also be designed to capture light waves beyond the visible light range.

[0122] Furthermore, microscope 1 includes a variable focal length optical element unit (zoom lens) 7, two zoom optical element units 8, a variable aperture element 19, and two video objectives 9. In this configuration, the variable focal length optical element unit (zoom lens) 7, the two zoom optical element units 8, and the two video objectives 9 are arranged in the beam path 6 between the object space region 5 or between the object arranged in the object space region and the aforementioned video cameras 2 and 3. Figure 1 In the beam path 6, a laser autofocusing device 10 is arranged between the focal length variable optical element unit 7 and the zoom optical element unit 8. In each beam path 6, a beam splitter 12 is arranged between the video objective lens 9 and the aforementioned video cameras 2 and 3. The beam splitter 12 creates separate partial beam paths, thus each of the aforementioned video cameras 2 and 3 is assigned a separate partial beam path in beam path 6. Furthermore, the microscope 1 optionally includes an ambient camera 11, which can capture the large field around the object area (e.g., a magnified surgical site) captured by the microscope, and can be used for tool tracking and navigation functions.

[0123] In addition to the four video cameras 2 and 3 mentioned above, the polarization determination arrangement also includes a plurality of polarization filters 20 to 24 and an evaluation device (not shown here). In this case, the corresponding polarization filters 21 to 24 are arranged upstream of each of the four aforementioned video cameras 2 and 3 in the beam path 6, and the polarization filter 20 is arranged downstream of the illumination device 4 and upstream of the object space region 5 in the beam path 6. In this case, the polarization filters 21 to 24 are configured, or can be configured, such that the polarization effects of the polarization filters 21 to 24 arranged upstream of at least one (preferably two) of the two designated other video cameras 3 and upstream of at least one (particularly two) of the aforementioned video cameras 2 designed to capture light waves of multiple wavelengths in the visible light wavelength range are different from each other in their respective cases. In other words, the polarization setting of at least one of the polarization devices 22 and 23 arranged upstream of one of the video cameras 2 (VIS cameras) designed to capture visible light during operation is different from the polarization setting of at least one of the polarization devices 21 and 24 arranged upstream of one of the other video cameras 3 (e.g., a fluorescence camera).

[0124] The polarization determination arrangement enables the analysis of the polarization state of light emitted by object 5, wherein multiple polarization measurements can be performed simultaneously using multiple video cameras 2, 3. This allows for the real-time capture and evaluation of necessary data. To create a polarization-resolved (e.g., three-dimensional) overall image of the object, polarizing filters or polarizers 20 to 24 with different configurations can be positioned upstream of the four cameras 2, 3 and downstream of the illumination device 4 in the beam path 6. These polarizing filters or polarizers are equipped, on the one hand, with suitable excitation and observation filters for the aforementioned fluorescence options, and on the other hand, include polarizers suitable for polarization determination.

[0125] If the alternative visualization arrangement according to the invention, as described at the outset, is used, the video camera 2 is configured as a polarization camera. In this variant, the additional video camera 3, beam splitter 12, and polarization filter arrangements 20 to 24 can be omitted.

[0126] The following simplified diagrams are used to describe the polarization optics of the system. Figure 2A schematic diagram illustrates the polarization optics operation mode according to the present invention, using a visual arrangement. In this case, the evaluation device 13 analyzes and evaluates image data captured by means of four cameras 2, 3, and synthesizes the data to form a three-dimensional overall image with polarization contrast. The created overall image is visualized or displayed to a user by means of a stereoscopic imaging device 14. 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 indicated by reference numeral 15. Within the scope of the data acquired through analysis and evaluation, the Stokes vector or a portion thereof is preferably known, and, in particular, multiple Mueller matrix coefficients, preferably more than four Mueller matrix coefficients, are known, and in particular, calculated. The polarization contrast is known by means of the known Mueller matrix coefficients.

[0127] Figure 3 An exemplary polarizing filter and its naming are schematically illustrated. In this case, the polarization effect of the filter is indicated by the direction of the transmitted polarization. Polarizers 20 to 24 each comprise several (preferably multiple) different polarizers, such as... Figure 3 One or more of the polarizers shown. Preferably, polarization can be set individually at each location in the polarizing filter device.

[0128] To measure the complete Stokes vector, four different polarizers are needed at filter positions 21 to 24. Figure 4 Examples of four different polarizers at filter positions are shown, where the division of polarizers among these four filter positions 21 to 24 can also vary. In surgical microscopy, the primary focus is likely on the linear polarization component, so the circular polarizer can optionally be omitted. Then, as... Figure 5 As shown, the circular polarizer can be replaced, for example, by a 135° filter to obtain redundancy when determining the total intensity.

[0129] exist Figure 6 In another variant shown, identical polarizing filters are arranged or positioned in front of the two video cameras 2 (VIS or RGB cameras) used for visible light to avoid interfering with stereoscopic imaging. In this case, it is advantageous that the illumination polarizations 4 and 20 are set orthogonal to the polarizations of the filters 22 and 23 upstream of the two video cameras 2 used for visible light. This... Figure 7 As shown, the Stokes vector components S0, S1, and S2 can be measured using unobstructed stereo imaging.

[0130] In digital surgical microscopes, Stokes parameters can also be measured using one or more polarizing cameras. These cameras achieve the four measurements required to determine the Stokes vector through small polarizing filters on the 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, such as... Figure 8 As shown. In this context, Figure 8 The polarization filter arrangement 24 is optional. The principle of a polarization camera is... Figure 9 As shown in the figure, four adjacent pixels 16 arranged in a plane are each provided with a polarizer, and each polarizer is offset from each of the other polarizers.

[0131] Available polarizing cameras (such as those from Sony) have 5 megapixels and achieve 23 frames per second. This means a time delay of 43 ms between two images, just below the sought-after 50 ms specification. In equation (1), these four polarizers correspond to , , and This allows for the measurement of the first three Stokes parameters. However, the fourth component cannot be measured. For imaging tissues in reflection, this may be a permissible limitation, as the structural features are essentially linear, meaning the linear polarization component should also be the primary influence. In the case of imaging deep tissues, fiber layers may be stacked and positioned with their orientations tilted relative to each other, which can raise critical issues. This corresponds to a combination of linear retardation plates with different orientations, which can lead to polarization plane rotation and consequently circular birefringence. To measure all Stokes parameters, one can, for example... Figure 5 A 0° quarter-wave delay plate is superimposed on a 135° or 45° polarizer. Then, the two are combined to form a circular polarizer.

[0132] Without a complete measurement of the Mueller matrix, Lu-Chipman decomposition as described at the beginning cannot be performed. Furthermore, surgical microscopes with polarization contrast do not necessarily require a complete and accurate measurement of the Mueller matrix; rather, they should provide good tissue contrast for the user (e.g., the surgeon). Extensive analysis has been conducted in this regard in the past.

[0133] A variant is described in [6]. In it, based on simulations of isotropic and anisotropic polarization effects, a series of parameters directly derived from the Mueller matrix coefficients are defined. Therefore, in this case, it is sufficient to measure a finite set of Mueller matrix coefficients and calculate the contrast derived from these coefficients. Relevant examples from [6] are summarized in the table below:

[0134]

[0135] However, these are just examples. There are even more meaningful combinations of Mueller matrix elements that can be used for image contrast in surgical microscopy techniques.

[0136] The linear anisotropic medium discussed in [6] (whose morphology is quite similar to that of biological fibers) exhibits the following symmetry of the Mueller matrix:

[0137] (twenty one)

[0138] Only the 3 × 3 subset is different from zero, and it is symmetric. Therefore, only 6 independent components need to be determined. .

[0139] To measure a portion of the Mueller matrix, it is necessary to irradiate not only one polarization state, but several polarization states. An obvious solution is to configure filter 20 as rotatable or supplemented with a ferroelectric liquid crystal filter. However, in this case, irradiation using multiple polarization states can only be performed sequentially in time. Since polarization imaging already just meets the desired specifications, sequential polarization irradiation in time is likely to significantly exceed the time delay of no more than 50 ms required for tissue contrast. If time cannot be used as a parameter to distinguish irradiation polarization, then within the scope of this invention, the wavelength of the irradiation light can be used as a parameter to distinguish irradiation polarization. If the two polarization states are arranged at different positions in the spectrum, then it is possible to irradiate using both polarization states simultaneously. In this case, the associated image can also be reconstructed using a spectral filter. That is, the irradiation must be polarized differently in two narrow spectral bands. If a “normal color impression” is still required, then unpolarized light or light of any desired polarization state should be present around said bands (see...). Figure 3 If a "normal color impression" is not required, dual-color illumination can be chosen. This can be achieved, for example, using two notch filters, such as... Figure 10 As shown.

[0140] Figure 10 Two diagrams schematically illustrate possible illumination of a spatial region of an object. Both diagrams plot the intensity I of the radiated input light as a function of wavelength λ. The upper diagram shows bicolor illumination with a first wavelength range 31 and a second wavelength range 32. These two wavelength ranges 31 and 32 are polarized in a manner deviating from each other. The lower diagram shows polycolor illumination, where the two wavelength ranges 31 and 32 are polarized in a manner deviating from each other, while the remaining spectral range 33 is unpolarized. This can be achieved, for example, by using two notch filters, such as... Figure 11As shown. In this case, the two narrowband polarized spectral components 31 and 32 are achieved by transmitting unpolarized light through two narrowband polarized notch filters. To achieve Figure 11 The concept shown can be applied, for example, to the use of polarizing bandpass filters in reflection, such as... Figure 12 As shown. Figure 12 The operating modes of a polarizing bandpass filter 34 from Semrock (https: / / www.semrock.com / a-new-class-of-polarization-optics-designed-specifically-for-lasers.aspx) are shown. The left side illustrates beam paths for three different wavelengths λ1, λ2, and λ3, along with their corresponding linear polarizations s and p. In this case, s and p identify mutually orthogonal linear polarizations. Figure 12 The right side shows a graph plotting the transmittance T of the filter 34 as a function of wavelength λ and polarization s and p.

[0141] use Figure 13 The configuration shown allows for the measurement of different Mueller matrix components based on the polarization state of the radiation input and the measured polarization state, for example... .exist Figure 13 In the variant shown, the radiation inputs are wavelengths or wavelength ranges λ1 and λ2 that are perpendicularly polarized to each other, wherein different cameras analyze individual polarized wavelengths. In the variant shown, a first video camera (RGB camera) 2 and a first additional video camera 3 for visible light analyze wavelength λ1, and a second video camera (RGB camera) 2 and a second additional video camera 3 for visible light analyze wavelength λ2.

[0142] Of course, other configurations can be considered; for example, the RGB camera 2 could be replaced by the monochrome camera 3, and vice versa. However, without a polarization camera, due to spectral division, only two Stokes vector components might be measured instead of three or four. Figure 13 The variant shown measures S0 and S1. However, these two Stokes vector components can also be S0 and S2, thus yielding the Mueller matrix components. .

[0143] exist Figure 14 In the variant shown, using two polarization cameras 17 as additional cameras 3 and employing two input polarizations, half of the Mueller matrix, i.e., eight Mueller matrix elements, can be measured. In this case, filter 20 (not shown here) is a polarization notch filter that allows only two wavelengths in the unpolarized illumination spectrum to pass through. and Polarization. The remainder of the illumination spectrum is unpolarized. Filter 21 is a filter for wavelength λ1 and optionally polarized 1, while filter 24 is a bandpass filter for wavelength λ2 and optionally polarized 2. Alternatively, the neutral beam splitter can also be in the form of a dichroic beam splitter, for example, a first beam splitter for wavelengths with the first polarization and a second beam splitter for wavelengths with the second polarization. This alternative is more optically efficient but compromises flexibility. The advantage of this method is that polarization becomes an additional option that does not interfere with standard imaging.

[0144] Figure 15 Another embodiment of spectral coding is shown, in which the spectral characteristics of the RGB channels of two color video cameras 2 are advantageously used. (See also: Regarding...) Figure 14 As described, filter 1 (not shown here) is in Figure 15 The middle element is also a polarizing notch filter, but it is now designed so that the filter is illuminated by four different wavelengths with clearly defined predetermined polarizations. The polarizations of the different wavelengths can be different or partially the same. A 1-chip camera or a 3-chip camera can be used as a video camera 2 (RGB camera). In the case of a 1-chip camera, a Bayer filter divides a sensor into three spectrally separated pixel arrays, while in a 3-chip camera, the beam-splitting prism used allows for spectral division among the three sensors. Figure 15 In this process, the wavelength of filter 20 is selected such that the RGB sensor detects wavelengths individually, without crosstalk between different wavelengths. For example, this can be achieved by irradiating with wavelengths of 400 nm, 540 nm, and 680 nm, such as... Figure 16 As demonstrated by the typical spectral sensitivity of the RGB sensor and Bayer filter. Figure 16 The diagram illustrates the relative spectral sensitivity of the beam splitter (top image) and Bayer filter (bottom image) as a function of wavelength. A fourth wavelength illuminating filter 20 is selected such that the two monochrome cameras 3 can detect the signal in a spectrally separate manner from the RGB camera 2. This can be achieved, for example, by illuminating with a wavelength in the infrared range (e.g., 800 nm), at which the RGB camera 2 is no longer sensitive. Of course, it is also conceivable to select different wavelengths and remove interfering wavelengths upstream of the sensor using a suitable notch filter. Therefore, filters 22 and 23 upstream of the RGB camera 2 are ideally designed as multi-bandpass filters for wavelengths of 400 nm, 540 nm, and 680 nm. Simultaneously, filters 22 and 23 can be designed to differ in their polarization characteristics. Filters 21 and 24 upstream of the additional video camera (monochrome camera) 3 are designed as bandpass filters for an 800 nm wavelength; similarly, filters 21 and 24 can optionally be designed to differ in their polarization characteristics.

[0145] Figure 15 An exemplary embodiment describes a special case, which can be summarized as follows: In the first step, the number N of detection channels existing in the system is determined. Figure 1 In the example shown, there are eight channels, with two additional video cameras 3 (monochrome cameras) providing two channels each, and two video cameras 2 (RGB cameras) providing an additional six channels for visible light. The system is now designed so that these N detection channels provide optimal tissue contrast for the respective applications. This is achieved by the fact that all N channels differ in at least one characteristic (e.g., in terms of spectrum and / or polarization).

[0146] A first possible exemplary embodiment of a system with eight detection channels involves irradiation using eight different polarizations separated spectrally, and detection using eight detectors in a single polarization analysis to achieve spectral separation. A second possible exemplary embodiment of a system with eight detection channels involves irradiation using two defined polarizations separated spectrally, and detection using eight detectors, wherein, in each case, four detectors analyze the spectral region using four different analyzers.

[0147] Figure 17 A method according to the invention is schematically illustrated in flowchart form for creating an image representation (preferably a stereoscopic image representation) of an object with polarization contrast by means of the above-described visualization arrangement (e.g., the visualization arrangement of a surgical microscope) according to the invention. The method includes: in step 41, irradiating light waves onto the object by means of an irradiation device; in step 42, capturing light waves emitted by the object after interaction with the irradiated light waves by means of at least three video cameras or at least two polarization cameras; and in step 43, creating a stereoscopic image representation preferably with 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, refer to [reference needed]. Figures 1 to 16 The explanation given.

[0148] List of reference numerals in the attached diagram:

[0149] 1. Surgical microscope with visual layout

[0150] 2 video cameras

[0151] 3 video cameras

[0152] 4 Irradiation device

[0153] 5. Object region, object

[0154] 6-beam path

[0155] 7. Variable focal length optical components (zoom lens)

[0156] 8 zoom optical components

[0157] 9 video objectives

[0158] 10 Laser autofocusing equipment

[0159] 11 Surrounding environment cameras

[0160] 12-beam splitter

[0161] 13 Evaluation Devices

[0162] 14 (stereo) imaging devices

[0163] 15 (Image) Data Transmission

[0164] 16 pixels

[0165] 17 Polarization Camera

[0166] 19 Variable Aperture Elements

[0167] 20 polarization filter device

[0168] 21 polarization filter device

[0169] 22 polarization filter device

[0170] 23 Polarizing filter device

[0171] 24 polarization filter device

[0172] 31 wavelength range

[0173] 32 wavelength range

[0174] 33 wavelength range

[0175] 34 polarizing bandpass filter

[0176] 41 Radiated input light waves

[0177] 42. Capturing light waves emitted by an object after its interaction with the light waves of the radiating input.

[0178] 43. To create an image representation with polarization contrast based on the generated polarization state of the radiated input light wave and / or the analyzed polarization state of the captured light wave.

[0179] I Intensity

[0180] T transmittance

[0181] λ wavelength

[0182] s-linear polarization

[0183] p-linear polarization

[0184] P00 degree polarizer

[0185] P9090 degree polarizer

[0186] P4545 degree polarizer

[0187] P135 135 degree polarizer

[0188] PC circular polarizer

[0189] PN neutral polarizer

Claims

1. A visualization setup (1) for microsurgery, the visualization setup comprising an imaging device (14), an irradiation device (4), and a polarization determination setup, Its features are, The polarization determination arrangement includes: at least two video cameras (2) and at least one additional video camera (3), the at least two video cameras being used to capture multicolor visible light, wherein each of the three aforementioned video cameras (2, 3) is assigned a separate portion of the beam path in the beam path (6); a plurality of polarization filters (20 to 24); and an evaluation device (13). In this configuration, at least one polarizing filter (21 to 24) is arranged upstream of each of the at least three video cameras (2, 3) in the beam path (6). Among them, these polarization filter devices (20 to 24) are configured or can be configured such that the polarization effects of the polarization filters (20 to 24) arranged upstream of the designated at least one other video camera (3) and arranged upstream of at least one of the aforementioned video cameras (2) for capturing multicolor visible light are different from each other. The evaluation device (13) is designed to use images captured by the video cameras (2, 3) to create an image representation with polarization contrast and to display the image representation by means of the imaging device (14). Among them, the high-resolution image representation with polarization contrast and the high-resolution image representation without polarization contrast of the object to be imaged captured by the same video camera used to capture multicolor visible light, and The evaluation device (13) is designed to display the created image representation with polarization contrast by means of the imaging device (14) in a manner superimposed on the white light image representation, which is captured by means of at least two video cameras (2) for capturing multicolor visible light.

2. The visual arrangement (1) as described in claim 1. Its features are, At least one polarizing filter (20) is arranged in the beam path (6) downstream of the irradiation device (4) and upstream of the object space region (5).

3. The visual arrangement (1) as described in claim 1 or 2. Its features are, At least one of these polarization filter devices (20 to 24) includes multiple polarizers that are different from each other.

4. The visual arrangement (1) as described in claim 1 or 2. Its features are, The at least one additional video camera (3) is designed to capture monochromatic light, or at least one of the aforementioned video cameras (2, 3) is in the form of a polarized camera.

5. The visual arrangement (1) as described in claim 4. Its features are, At least one polarizing filter (22, 23) arranged upstream of a video camera (2) used to capture multicolor visible light includes a circular polarizer.

6. The visual arrangement (1) as described in claim 1 or 2. Its features are, The evaluation device (13) is designed to use images captured by these video cameras (2, 3) to determine the set of Mueller matrix coefficients and to determine the polarization contrast derived from said coefficients.

7. The visual arrangement (1) as described in claim 1 or 2. Its features are, The polarization filter (20) arranged in the beam path (6) downstream of the irradiation device (4) and upstream of the object space region (5) is configured to simultaneously polarize at least two defined mutually deviated wavelengths in a manner that is deviated from each other.

8. The visual arrangement (1) as described in claim 1 or 2. Its features are, At least one of these polarization filtering devices (20 to 24) includes a wavelength filter and / or a wavelength selective polarizer.

9. The visual arrangement (1) as described in claim 1 or 2. Its features are, The irradiation device (4) is designed to emit bicolor light.

10. The visual arrangement (1) as described in claim 1 or 2. Its features are, The irradiation device (4) is designed to emit multicolor light, and the polarization filter device (20) arranged in the beam path (6) downstream of the irradiation device (4) and upstream of the object space region (5) includes at least one notch filter and / or multiple bandpass filters.

11. The visual arrangement (1) as described in claim 1 or 2. Its features At least one beam splitter (12) is arranged in the beam path (6) between the object space region (5) and the video cameras (2, 3).

12. A visualization setup (1) for microsurgery, the visualization setup comprising an imaging device (14), an irradiation device (4), and a polarization determination setup, Its features are, The polarization determination arrangement includes two polarization cameras (17) and an evaluation device (13), wherein each of the two polarization cameras (17) is assigned a separate portion of the beam path in the beam path (6). The evaluation device (13) is designed to create an image representation with polarization contrast using images captured by the polarization cameras (17) and to display the image representation by means of the imaging device (14). The evaluation device (13) is designed to display the created image representation with polarization contrast in superimposed with a white light image representation captured by the two polarization cameras (17) by means of the imaging device (14). Among them, the high-resolution image representation of the object to be imaged by the same polarization camera with polarization contrast and the high-resolution image representation without polarization contrast are shown.

13. A method for creating an image representation of an object (5) with polarization contrast by means of a visualization arrangement (1) for microsurgery as described in any one of claims 1 to 12. Its features are, The method includes the following steps: -The irradiation device (4) is used to radiate light waves (41) onto the object (5). -The light waves emitted by the object (5) after the object (5) interacts with the light waves of the radiating input are captured (42) by means of the at least three video cameras (2, 3) or the at least two polarization cameras (17). - Create (43) an image representation with polarization contrast based on the generated polarization state of the light waves from these radiated inputs and / or the analyzed polarization state of the captured light waves.

14. The method as described in claim 13, Its features are, The light wave in a defined polarization state is radiated by means of the irradiation device (4) and the polarization filter device (20) arranged in the beam path (6) downstream of the irradiation device (4) and upstream of the object (5).

15. The method as described in claim 13 or 14, Its features are, The polarization state of the received light wave is analyzed by means of the at least three video cameras (2, 3) and the polarization filters (21 to 24) arranged upstream of the video cameras in the beam path (6) and / or by means of the polarization cameras (17).

16. The method as described in claim 13 or 14, Its features are, Using the evaluation device (13), an image representation with polarization contrast is created based on the analyzed polarization states of these captured light waves, wherein the set of Mueller matrix coefficients is determined by means of images captured by these video cameras (2, 3) and / or these polarization cameras (17), and the polarization contrast derived from said coefficients is determined.

17. The method as described in claim 13 or 14, Its features are, The image representation with polarization contrast was created within a time interval of less than 50 ms, and / or the resolution of the created stereoscopic image representation with polarization contrast deviates from the resolution of the corresponding image representation without polarization contrast by less than 10%.

18. The method of claim 17, Its features are, The image representation with polarization contrast was created over a time interval of less than 50 ms and displayed as an overlay on the multicolor image representation.

19. A microscope comprising the visualization arrangement (1) as described in any one of claims 1 to 12 or designed to perform the method as described in any one of claims 13 to 18.

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