Arrangement, computer program and method for determining a volume of a 3D reconstruction of an object region

Abstract

The invention relates to an arrangement having an OCT device, comprising an object, and having a computer unit connected to the OCT device and having a computer program for determining a 3D reconstruction of a volume of interest by processing OCT scan information obtained by scanning the volume of interest with the OCT device and determining a position of a part of the object in the volume of interest. The computer program has a calculation routine for determining a target region in the 3D reconstruction of the volume of interest, which determines a guiding variable of the object for the target region. The computer program contains a path planning routine which calculates an optimal path from the object to the target spatial position using a criterion which is a shadowing measure quantifying shadows caused by the object occurring in the calculated 3D reconstruction. The invention also relates to a computer program and a method for determining a 3D reconstruction of a volume of interest of an object in an object region.

Description

TECHNICAL FIELD

[0001] The invention relates to an arrangement comprising an OCT device for scanning an object volume in an object volume by means of an OCT scanning beam, and comprising an article having a section which can be arranged in the object volume and which can be positioned in the object volume by means of the OCT device, and comprising a computer unit which is connected to the OCT device and which contains a computer program for determining a 3D reconstruction of the object volume and determining the relative position of the section of the article in the object volume by processing scan information obtained by scanning the object volume by means of the OCT device. The invention also relates to a computer program and a computer-implemented method for determining a 3D reconstruction of an object volume. BACKGROUND

[0002] Optical coherence tomography (OCT) is a method for acquiring volume data of, in particular, biological tissue by scanning the tissue by means of an OCT scanning beam consisting of a temporally incoherent but spatially coherent laser which is guided in a sample beam path and a reference beam path. OCT allows for the positioning of an object such as a surgical object in an operating field.

[0003] WO 2016 055422 A1 and US 2017 / 0209042 A1 have each disclosed an arrangement of the type set out at the outset. These documents describe a surgical system comprising an OCT device and comprising a surgical instrument having an active section which can be positioned by means of the OCT device. These documents state that a target region of the surgical instrument should be determined in dependence on reference data, and that an offset of the surgical instrument relative to the target region should be used as a criterion for triggering an instrument function.

[0004] US 2019 / 0000563 A1 describes a system for determining the relative position and orientation of an instrument tip during an ophthalmic surgery. In this case, in particular, the tissue of an eye is detected by means of OCT, and the relative position and orientation of the instrument tip is determined on the basis of a marker attached to the instrument in a coordinate system which takes the detected tissue as a reference by means of image capture, by means of a magnetic sensor, by means of an ultrasound sensor or by means of an inertial sensor.

[0005] US 2016 / 0249989 A1 discloses a visualization system which can present visible virtual structures with reference to a patient's body.

[0006] EP 3 461 411 A1 has disclosed processing OCT data on various object volumes to form a model by means of references to OCT data relating to different object volumes.

[0007] US 2018 / 0263706 A1 teaches processing of patient images, which contain shadow structures and are captured by means of penetrating radiation.

[0008] US 2012 / 0190976 A1 describes controlling the release of an active substance by means of a microcatheter which has been introduced into a blood circuit of a patient by determining the pressure in the active substance reservoir by means of a pressure sensor and controlling the outflow of the active substance in the active substance reservoir by means of a microvalve. SUMMARY

[0009] It is an object of the present invention to simplify surgical interventions by a surgeon in an operation area which is difficult to access.

[0010] This object is achieved by an arrangement as described below, by a computer program as described below and by a method as described below. Advantageous embodiments of the invention are specified in the following.

[0011] The arrangement provided by the invention comprises an OCT device for scanning an object volume arranged in an object region using an OCT scanning beam and an object having a section which can be arranged in the object region and which can be positioned in the object volume by means of the OCT device. Furthermore, the arrangement comprises a computer unit which is connected to the OCT device and has a computer program for determining a 3D reconstruction of the object volume and determining the relative position of the section of the object in the object volume by processing OCT scanning information obtained by the OCT device by scanning the object volume. In this case, the computer program has a calculation routine for determining a target region in the 3D reconstruction of the object volume, which determines a guidance variable of the object in relation to the target region. The computer program comprises a path planning routine for calculating an optimal path of the object to a spatial target position on the basis of a certain criterion. In this case, the criterion is a shadowing measure which quantifies shadows caused by the object which are present in the calculated 3D reconstruction.

[0012] The OCT device in the arrangement according to the application comprises a source of temporally incoherent and spatially coherent laser light with a coherence length Ic, which is fed to a sample beam path and a reference beam path. The sample beam path is directed at the tissue to be examined. In the OCT device, the laser light that is radiated back into the sample beam path as a result of scattering centers in the tissue is superimposed on the laser light from the reference beam path. As a result of this superimposition, an interference signal is generated. The position of the scattering centers of the laser radiation in the tissue to be examined can be determined from this interference signal. In particular, the OCT device in the surgical system according to the application can be designed as a "time-domain OCT" or a "Fourier-domain OCT".

[0013] The path planning routine facilitates improved automation of the surgical method and increased accuracy of the item guidance while increasing the flexibility of the surgeon.

[0014] By virtue of minimizing the occlusion measure of the items or by virtue of not exceeding a specified threshold, occlusions in the data can be avoided from the outset. By way of example, if the light source positions and the position and orientation of the items in the object region are known, the occluded regions in the data and the magnitude of the occlusion can be calculated in advance for a certain path of the item to the target position in the target region.

[0015] In this case, it is advantageous if the computer program contains a visualization routine for visualizing the optimal path of the item for the surgeon. The surgeon can thus verify the path of the item even before the movement of the item and can implement a corrective intervention if necessary.

[0016] In an advantageous embodiment of the application, the surgeon can specify criteria for the path planning routine so that they themselves can directly influence the automated implementation of the operation by selecting the criteria.

[0017] In this case, the criteria can also in particular minimize the path length of the path along which the item is displaced; it can protect sensitive regions of the item and the object region volume by observing a minimum distance of the item from these regions when planning the path, or it can avoid occlusions in the data caused by the items. Since the optimization problem is formulated exactly with an objective function to be optimized, a plurality of criteria within the scope of the path planning can also be taken into account in a synchronized manner. In this case, the criteria can be included in the objective function, each weighted in accordance with its relevance.

[0018] In particular, the injection of stem cells into the retina tissue to treat so-called dry macular degeneration (AMD) is advantageous to reduce the vitreous warts modification and to allow the retinal pigment epithelium, which has been damaged, and the damaged photoreceptors to heal again. However, it is essential here that the surgeon releases the stem cells injected into the retina tissue at the right place and in the right amount. Precise positioning is also important for placing implants on the retina, for example for placing so-called nanoretinal implants. Furthermore, for some operations, it is important to remove the vitreous humor as precisely as possible in the preparation phase of the operation.

[0019] In particular, therefore, the positioning of items such as surgical instruments, implants and tissue as precisely as possible is desirable for the successful completion of such operations.

[0020] In the present case, the term 3D reconstruction denotes the process of capturing the shape and appearance of a real object or part thereof. By way of example, the 3D reconstruction can be used as a depth map, a point cloud or a mesh. The process can be performed using active or passive techniques. Active techniques use distance measuring devices to actively interact with the object to be reconstructed in a mechanical or radiometric manner. Passive techniques, in contrast, only use sensors to measure radiation reflected or emitted by the surface of the object and use this to infer the 3D structure of the object by image understanding.

[0021] The present invention understands the target region as a part of the 3D reconstruction of the object region volume, in which the item is to be made to function by performing a function of the item or by placing the item here. For this purpose, this part can contain the target position.

[0022] The determination of the target region in the 3D reconstruction of the object region volume and the determination of the guidance variable of the item by means of a computer program is advantageous for the automation of the guidance of the surgical instrument and further items during the operation.

[0023] The present invention understands the guidance variable as a variable determined by means of a computer program and used for guiding the item in the object region. Here, such a variable represents a property of a procedure or a state that can be determined quantitatively when guiding the item. The guidance variable can for example directly describe the guidance of the item in the form of a direction, a speed, a position or a temporal range. The guidance variable can also for example indirectly describe the guidance of the item in the form of an amount, a volume or a spatial range of a medium, which is to be released into the object region or removed from the object region by means of the item. Here, the guidance variable is advantageously determined by processing the data of the target region.

[0024] In particular, the item can be a surgical instrument, and the section of the item can be an active section of the surgical instrument.

[0025] It is advantageous if markers that can be located by means of the OCT scanning beam are arranged in the section of the object and / or in the object region. This makes it easy to determine the relative position of the object in the object region volume and / or to determine a 3D reconstruction and thus to facilitate automation of the surgical method.

[0026] Preferably, the computer program contains routines for generating a guidance variable in the form of a control signal for the object, in particular a surgical instrument. Alternatively, the computer program can generate a control signal for the object on the basis of the determined guidance variable relating to the target region. These measures allow automation of the guidance of the object. Furthermore, the accuracy of the guidance of the object can be increased, thereby increasing the chances of success of the surgery and reducing the risk of complications caused, for example, by blood vessel damage or hand tremor of the surgeon.

[0027] In a preferred embodiment, the object is a surgical instrument in the form of a capillary tube having an opening for releasing a medium. By way of example, in this case the surgical instrument is an injection needle for injecting stem cells for treating AMD, an operation that can be performed in an automated manner to the greatest possible extent on the basis of the arrangement and the computer program according to the application.

[0028] Further preferably, the computer program has a computing routine for determining a target value for the volume of the released medium as a guidance variable by processing the target region in the 3D reconstruction of the object region volume and / or by processing data determined prior to the operation and / or by processing OCT scanning information obtained by scanning the object region volume by means of the OCT device and / or by inputting a target value by the surgeon. For example, the target value for the volume of the released medium can be determined by means of image processing from the specified data or a combination of these data. This measure is advantageous in that the determination of the target value can be carried out directly by the computer program automatically. When using the 3D reconstruction or the OCT scanning information, this measure has the additional advantage that the target value is adapted to the conditions currently present in the object region of the patient and not to data recorded at an earlier time.

[0029] Advantageously, the computer program has a computing routine for determining an actual value for the volume of the medium released into the target region by comparing data of the target region in the 3D reconstruction of the object region volume before and during the release of the medium and / or scanning information of the target region obtained by scanning the object region volume by means of the OCT device. In this case, the actual value for the volume of the medium released in the target region can be determined by means of image processing. Furthermore, changes in the volume can be determined by evaluating difference images that arise as differences of OCT data captured at different times and / or 3D reconstructions determined at different times. On the basis of these difference images, it is furthermore possible to infer the location of possible leaks.

[0030] The calculation routine of the computer program advantageously is designed to determine the difference between the target value and the actual value of the volume of the medium released into the target region as a guiding variable for readjusting the volume of the released medium. Thus, the volume of the medium that still has to be released into the target region from the surgical instrument is determined automatically. This facilitates an automatic readjustment of the volume of the released medium on the basis of the data on the target region present. These measures take account of possible leaks and ensure that the specified medium volume actually also applies to the target region. If necessary, the target region or the target position in the target region can be adjusted while the medium is being released.

[0031] On the basis of the determined guiding variable for readjusting the volume of the released medium, the computer program can generate a control signal for the surgical instrument for releasing the medium and / or a volume indication signal for the surgeon.

[0032] A further preferred embodiment of the application relates to removing a substance from a target region determined in a 3D reconstruction of an object volume. By way of example, the substance can be tissue, water or vitreous humor. In this case, a calculation routine of the computer program serves to determine the position of the substance to be removed and / or the amount of the substance to be removed as a guiding variable, by processing the target region in the 3D reconstruction of the object volume and / or by processing data determined prior to the operation and / or by processing scanning information obtained by scanning the object volume by means of an OCT device and / or by inputting a target value by the surgeon. In this case, the position of the substance to be removed that is still present in the object volume can be determined by means of image processing of the target region in the given data. Alternatively, for a given position, the volume of the substance to be removed that is still present can also be determined. On the basis of these guiding variables, a control signal for automatically displacing the article in the object volume to the substance to be removed that is still present can then be generated.

[0033] In order to allow complete removal of the substance to be removed, this substance can be rendered identifiable by injecting a marker, in particular triamcinolone acetonide. This allows more accurate removal of the substance. This increases the probability of the operation being successful and protects surrounding blood vessels.

[0034] The computer program advantageously has a visualization routine for visualizing the position of the substance to be removed in the object volume and / or the amount of the substance to be removed. To this end, for example, the 3D reconstruction can be augmented by means of markers on the positions. Alternatively, it is also possible to present an isogram relating to the target region of the object volume, in which the amount of the substance to be removed is specified as a height at various positions. Alternatively, a display bar indicating the amount of the substance to be removed can be presented for the current position of the article in the object volume.

[0035] By way of example, the substance can be the material of the vitreous humor. The vitreous humor removal is performed using an item, for example a glass knife. A precise vitrectomy without residues is important for the success of a retinal implant surgery, since it facilitates an improved signal-to-noise ratio. In this case, the vitreous humor to be removed is visualized for the surgeon on the basis of a contour map which indicates for each point on the retina the amount of vitreous humor to be removed which lies on the point. In this case, the computer program is advantageously designed to continuously determine the boundary between the vitreous humor and the solution used to flush the operating zone within the range of the vitrectomy and / or to display said boundary to the surgeon. This measure is advantageous in that the boundary between the vitreous humor and the solution used to flush the operating zone can be clearly highlighted in the visualization of the operating zone. Automated detection of vitreous humor residues by means of segmentation facilitates the measurement of the remaining thickness of the layer. The vitreous humor residues can then be displayed to the surgeon in each visualization of the operating zone, thus simplifying the implementation of the surgical procedure and reducing the risk to the patient.

[0036] In yet another advantageous embodiment, the item is in the form of an implant.

[0037] Furthermore, it is advantageous if the computer program is designed to determine a spatial target position in the target region in the 3D reconstruction of the object region volume as a guidance variable, taking into account characteristic features of the target region in the 3D reconstruction of the item and / or of a further item and / or of the object region volume and / or taking into account geometric relationships between these items, in particular offset information. In this case, the characteristic features in particular represent the dimensions of, for example, the implant or of a portion of the implant, but also the dimensions of the further item, for example in the form of a surgical instrument, or of a region of the target region. The characteristic features can also describe the structure, for example 3D electrodes on the back side of the item in the form of an implant, or the course of blood vessels in the object region volume. The geometric relationships in particular describe the relative positions of the regions with respect to one another, for example the distance of the item from a blood vessel in the object region volume. The advantage of taking into account the characteristic features and / or the geometric relationships when determining the guidance variable by means of the computer program is that the attachment of the item in the object region volume can be performed automatically and more accurately and with the lowest possible risk of complications. Advantageously, the position of the item, for example the implant, is verified after the attachment of the item in its target region.

[0038] Preferably, in all embodiments, OCT angiography data of the subject volume is generated in dependence on scan information obtained by scanning the subject volume by means of an OCT device. OCT angiography is a clinical examination method that allows for a non-invasive three-dimensional representation of the vascular structure of the retina and choroid. From a technical perspective, OCT-A is a development of optical coherence tomography (OCT). Due to more powerful software and hardware, OCT-A is not only advantageous for morphological analysis, but also for three-dimensional retinal and choroidal perfusion analysis. In this case, the computer program is advantageously designed for determining the position and / or size of blood vessels in the target region on the basis of the OCT angiography data. The advantage of representing and / or measuring blood vessels in the target region by means of OCT-A is that the computer program's calculation routine takes the position and / or size of the blood vessels into account, which determines the item's target region-related guidance variable when guiding and placing the item and when determining the target region or the target position within the target region. This avoids complications due to damage to relatively large blood vessels during the intervention.

[0039] In particular, if the computer program has a position calculation routine for determining a spatial target position in the target region of the item, it is advantageous here if the position calculation routine is designed to minimize the number of blood vessels that are punctured when the item is placed at the spatial target position. This measure also minimizes the probability of damaging relatively large blood vessels or a larger number of blood vessels than necessary during the operation.

[0040] An advantageous embodiment of the application comprises a device for visualizing the relative position of a section of the item in the 3D reconstruction of the subject volume and / or the preoperatively determined data and / or the target region-related guidance variable to be determined and / or a variable derived from this guidance variable. Thus, the surgeon can permanently monitor the relative position of the item, for example an implant or a surgical instrument, within the 3D reconstruction of the subject volume. It is also possible to visualize the preoperatively determined data in order to display, for example, a preoperatively determined target region or further information planned before the surgical operation to the surgeon. It is also possible to visualize the determined guidance variable, such as a control signal for displacing the item and the volume to be released or the amount of substance to be removed, for the surgeon. This also applies to a variable derived from the guidance variable, for example a volume to be readjusted, which is determined in dependence on a previously determined guidance variable in the form of a target value for the volume to be released. The computer program can generate acoustic, optical or haptic indication signals for the surgeon on the basis of the determined target region-related guidance variable and / or the variable derived from this guidance variable.

[0041] An advantageous development of the application provides that the computer program comprises a shadowing routine for determining a corrected 3D reconstruction of the object volume, which identifies regions shadowed by the item and which specifies compensation rules for the 3D reconstruction of the object volume in relation to these regions. Thus, a corrected 3D reconstruction of the object volume without shadowing can be determined, which shadowing would reduce the visibility of details in the individual regions. This ensures better manageability for the surgeon, since the 3D impression of the object volume is improved and the data of the target position and / or target region to be determined is more accurate. This also reduces the risk of complications occurring during the operation, since important regions in the data are not covered by shadows.

[0042] In this case, the shadowing routine for identifying the regions shadowed by the item and / or for specifying the compensation rules for the 3D reconstruction can use OCT data from different recording times, as described in EP 3 005 937 Al. As an alternative thereto, the shadowing routine for identifying the shadowed regions and / or for specifying the compensation rules can use data from other modalities, for example, optical data, MRI data, ultrasound images or CT data. By way of example, shadows in these data can be easier to identify than in OCT data, or these data can even be shadow-free. Data 92 determined prior to the operation can also be used for this purpose. Alternatively, the shadowing routine for identifying and replacing shadows can also take into account the currently calculated 3D reconstruction 94 and / or the currently recorded OCT data.

[0043] In order to identify the shadowed regions, for example, the gray values of the acquired OCT data can be analyzed and compared with the gray values in the surroundings or at different times. By defining a threshold, points with a gray value below the threshold can be identified as shadows. In order to identify the shadows, the contours of the edges in the image can also be taken into account. In this case, long, straight edges indicate shadows of artificial items, since long, straight edges generally do not occur in the tissue of the body. Alternatively, if the positions of the light source and the item are known during the operation, the positions of the shadows can also be calculated by means of ray tracing.

[0044] Alternatively, the occlusion routine can replace the occluded regions with data relating to the regions occluded by the item in the 3D reconstruction of the object region volume, which data is simultaneously acquired at a location away from the shadow of the element. Alternatively, the occlusion routine can replace the occluded regions with computer program generated data, for example by means of a inpainting method as described in the document "Liu, Yaojie und Shu, Chang, A comparison of image inpainting techniques, Proceedings of SPIE - The International Society for Optical Engineering, 2015", the entire content of which is hereby incorporated by reference and the disclosure of which is incorporated into the description of the present invention. The advantage of these measures is that the information within the occluded regions can be represented as realistically as possible, which contributes to the safety of the patient. Furthermore, these measures facilitate a representation of the 3D reconstruction without the troublesome element shadow, which is easy to implement and requires little computing time.

[0045] An advantageous development of the present invention provides that the computer program is designed to determine a spatial target position of the item in the 3D reconstruction of the object region volume. Preferably, the spatial target position of the item is here determined in a target region within the object region volume. This measure contributes to the automation of the surgical method and to a greater accuracy in guiding the item.

[0046] Advantageously, the computer program is designed to determine, from the spatial target position, offset information about a spatial offset of a section of the item. On the basis of this offset information, the computer program is able to automatically generate control signals for guiding the item, so that this measure also contributes to the automation of the surgical method and to the accuracy of the item guidance.

[0047] An advantageous embodiment of the application provides that the computer program is designed to determine the 3D reconstruction of the object volume from data obtained by examining the object volume using an imaging method, in particular by scanning the object volume with the aid of an OCT scanning beam of an OCT device, and / or from data determined prior to the examination, and / or from data relating to sensor signals for determining the position of a section of the item in the object volume. In this case, the person skilled in the art can use: conventional methods for calculating a 3D reconstruction of the object volume, for example as described in the publication "Justin A. Eichel, Kostadinka K. Bizheva, David A. Clausi, Paul W. Fieguth, Automated 3D Reconstruction and Segmentation from Optical Coherence Tomography, Proceedings of the European Conference on Computer Vision (ECCV), 2010, p. 44-57" or a simultaneous localization and mapping method (SLAM), for example as described in the publication "Hugh Durrant-Whyte, Tim Bailey, Simultaneous Localization and Mapping (SLAM): Part I The Essential Algorithms, Robotics and Automation Magazine, 2006". The entire contents of the two aforementioned publications are hereby incorporated by reference and their disclosure is incorporated into the description of the application. The advantage of this measure is that the calculated 3D reconstruction can be implemented with the greatest possible accuracy and, as a result, the result is as realistic as possible. This increases the safety of the patient.

[0048] It is also advantageous if the computer program is designed to determine the relative spatial position of the data by means of a registration method, said data comprising data from the following group: scanning information obtained by means of an OCT device by scanning a volume of the object region, a volume of the object region, data from further imaging methods, in particular optical image representations, MRI data, CT data, ultrasound images, endoscopic images, the position of a section of the item, preoperatively determined data, position sensor signals. By using different types of data, different aspects of the target region in the volume of the object region can be taken into account and / or represented. Furthermore, the use of redundant information in the data from different modalities makes the result of the registration method more accurate.

[0049] For the registration method, methods known to the person skilled in the art can be utilized, in particular methods for registering medical data, as found in the publication "F. Oliveira, J. Tavares, Medical Image Registration: a Review, Computer Methods in Biomechanics and Biomedical Engineering, 2014 [F. Oliveira, J. Tavares, Medical Image Registration: a Review, Computer Methods in Biomechanics and Biomedical Engineering, 2014]", for example, the entire content of which is hereby incorporated by reference and the disclosure of which is incorporated into the description of the application.

[0050] Furthermore, it is advantageous if the computer program is designed for continuous registration of the data. Thus, the result of the registration is always adapted to the conditions prevailing at the time, thereby increasing the safety of the patient.

[0051] Preferably, in this case the generation of the OCT data and the calculation of the 3D reconstruction and the registration of the various data are carried out in real time, in order to advantageously visualize the item in the current volume of the object region for the surgeon in real time, so that the surgeon can always verify the course of the operation. This measure also increases the safety of the patient.

[0052] In an advantageous development of the method, the OCT device is designed for continuous scanning of the object region volume by means of the OCT scanning beam and / or the OCT device is designed for continuous scanning of a region of the section of the object region volume containing the item by means of the OCT scanning beam. It is advantageous if the computer program is designed for continuous determination of the 3D reconstruction of the object region volume and / or for continuous determination of the relative position of the section of the item in the object region volume. This is because the OCT scanning information and the 3D reconstruction of the object region volume generated on the basis of these data and the relative position of the item in the object region are always adapted to the currently prevailing conditions, thus improving the manageability of the system and the safety of the patient. In particular, it is advantageous here if the determination of the OCT scanning information and the 3D reconstruction and the relative position of the section of the item in the object region volume are carried out in real time.

[0053] It is advantageous if the computer program contains a scanning routine for scanning the object region volume and / or the section of the item using a specific scanning pattern and / or for adjusting the scanning rate, i.e. scanning the object region volume at a lower rate compared to the position of the section of the item. This ensures that rapidly changing regions, in particular the item, are scanned at a higher rate than regions that are usually only changing slowly. This measure saves computing time and makes the determined relative position of the item more accurate.

[0054] It is advantageous to provide the data determined preoperatively from a memory connected to the computer unit during the surgical procedure. In this case, the data determined preoperatively can originate from the group comprising: an image of the object region, in particular a further region of the section of the object region, an image or data of the target region, a distance, a target position, geometric data of the item, in particular its dimensions or material properties such as reflection properties, a sensor signal, biometric patient data, in particular biometric data such as pupil size, or the distance between the two eyes. The computer program contains a routine for determining the target region and / or the target position of the item in the data determined preoperatively and a registration routine for registering the data determined preoperatively with the 3D reconstruction of the object region volume and a transfer routine for transferring the target region and / or the target position in the data determined preoperatively to the 3D reconstruction of the object region volume. Thus, it is possible to automatically transfer information items such as the target region and / or the target position from the data determined preoperatively to the 3D reconstruction present. This facilitates the overall automation of the surgical method and the accurate positioning of the target region and / or the target position in the 3D reconstruction on the basis of the preoperative data.

[0055] Furthermore, it is advantageous if the computer program is designed to determine the target region and / or the spatial target position in the 3D reconstruction of the object region volume on the basis of the preoperatively determined data by means of the application of a method for segmenting tissue structures and / or tissue layers. This measure contributes to a higher degree of automation of the surgical method.

[0056] It is advantageous if the computer program is designed to adapt the method for calculating the 3D reconstruction and / or the method for calculating the relative position of the section of the item in the object region volume on the basis of certain criteria. In this case, it is further advantageous if the method is adapted continuously during the surgical procedure. Preferably, the criteria take the properties of the data and / or the object region and / or the item and / or the arrangement and / or the registration method and / or the currently calculated 3D reconstruction and / or the currently calculated relative position of the section of the item into account during this adaptation. In particular, the criteria take the availability of the data and / or the measurement accuracy of the data and / or the data quantity and / or the data type and / or the type or quantity of the data of different modalities and / or the characteristic features of the object region in the form of the type or properties of the tissue or material in the object region and / or the characteristic features of the item in the form of its dimensions or material properties and / or the characteristic features of the devices of the arrangement in the form of the settings or properties of the individual components or the illumination settings and / or the properties of the method in the form of its suitability for the present data or its speed or accuracy or the quality of the currently calculated 3D reconstruction and / or the quality of the currently calculated relative position of the section of the item into account. These measures make the 3D reconstruction of the object region volume and / or the relative position of the section of the item in the 3D reconstruction of the object region volume more accurate. This contributes to a more comprehensive automation of the method. BRIEF DESCRIPTION OF DRAWINGS

[0057] In the following, advantageous exemplary embodiments of the application are described on the basis of schematic drawings,

[0058] In the drawings:

[0059] Figure 1 A first arrangement with a surgical microscope, with an OCT device for scanning the object region and with an item in the form of a surgical instrument in the form of an injection needle is shown;

[0060] Figure 2 An enlarged view of the surgical instrument is shown;

[0061] Figure 3 A section of a part of the retina is shown;

[0062] Figure 4 The transfer of the target region on the basis of the preoperatively determined data to the 3D reconstruction of the object region volume is shown;

[0063] Figure 5Aand

[0064] Figure 5B image data related to an OCT-B scan of a volume of a subject area having a non-uniformity during injection of stem cells is shown;

[0065] Figure 6 a second arrangement with a surgical microscope, with an OCT device for scanning a subject area, with an item in the form of a surgical instrument and with an image providing device is shown;

[0066] Figure 7 a third arrangement with a surgical microscope, with an OCT device for scanning a subject area, with an item in the form of a surgical instrument and with a robotic unit is shown;

[0067] Figure 8 a fourth arrangement with a surgical microscope, with an OCT device for scanning a subject area, with an item in the form of a surgical instrument, with an image providing device and with a robotic unit is shown;

[0068] Figure 9 an item in the form of an applicator for a further item in the form of a retinal needle is shown;

[0069] Figure 10A a front side of an item in the form of an implant for a retina is shown;

[0070] Figure 10B a back side of an item in the form of an implant for a retina is shown;

[0071] Figure 10C a magnified partial view of an item in the form of an implant with a 3D electrode is shown;

[0072] Figure 11 a first image of an operating area in an eye interior of an eye of a patient, with an applicator for a retinal needle and with an implant, captured by means of a camera is shown;

[0073] Figure 12 a further image of an operating area in an eye interior of an eye of a patient, with an applicator for a retinal needle and with an implant, captured by means of a camera is shown;

[0074] Figure 13 an image of an operating area in an eye interior of an eye of a patient, with a glass knife for a vitrectomy producing a shadowed area, captured by means of a camera is shown;

[0075] Figure 14 an image of a fundus of an eye of a patient with visualization of blood vessels based on OCT angiography data is shown; and

[0076] Figure 15 The image shows an operating area inside a patient's eye, with an implant and blood flowing from a damaged blood vessel in the patient's retina, captured by a camera. Detailed Implementation

[0077] Figure 1 The arrangement 10 shown includes a surgical microscope 16 for visualizing the object region 18 at a certain magnification. By way of example, the surgical microscope 16 could be from Carl Zeiss Meditec AG. Lumera 660Rescan surgical microscope. Arrangement 10 includes an OCT device 20 providing an OCT scanning beam 21, which scans the volume 22 of the target area at the patient's eye 14 using A, B, and C scans, as described, for example, in Chapter 3, pages 45 through 82 of the following document: A. Ehnes, "Entwicklung eines Schichtsegmentierungsalgorithmuszur automatischen Analyse von individuellen Netzhautschichten in optischen "B-Scans", Dissertation, University of Giessen (2013) [A. Ehnes, Development of a Layer Segmentation Algorithm for Automatic Analysis of Individual Retinal Layers in Optical Coherence Tomography -B-Scans, Dissertation, University of Giessen (2013)].

[0078] Arrangement 10 includes an article 24 in the form of a surgical instrument having a segment 84 that can be configured in an object area 18 and positioned in the object area volume 22 by means of an OCT device 20 based on a marker 78.

[0079] The surgical microscope 16 includes stereoscopic observation beam paths 38 and 40, which facilitates examination of the patient's eye 14 through the microscope objective 42 in the object area 18. The surgical microscope 16 further includes a zoom system 44 and an eyepiece 46. The surgical microscope includes an illumination device 48 that illuminates the object area 18 with illumination light through the microscope objective 42 to achieve stereoscopic visualization of the patient's eye 14 in the eyepiece 46.

[0080] The OCT device 20 provides an OCT scanning beam 21 with short coherent light, which is directed through the microscope main objective 42 into the object region 18 in the object region volume 22 by means of adjustable scanning mirrors 50, 52 and beam splitters 54 and 56. Light of the OCT scanning beam 21 scattered in the object region volume 22 is at least partially returned to the OCT device 20 via the same optical path. The optical path of the scanning light is then compared to a reference path in the OCT device 20. With this, it is possible to determine the distance of the scattering centers in the object region 18 from the object region volume 22 with a resolution of the order of magnitude of the coherence length I c The corresponding accuracy detects the precise position of the scattering centers in the object region 18, in particular the position of the optically effective area.

[0081] In the surgical microscope 16, there is a device 58 for controlling the OCT scanning beam 21 and for setting the position of the object region volume 22 scanned by the OCT scanning beam 21 in the object region 18. The device 58 comprises a computer unit 60. The computer unit 60 has an input interface 61 as a device for inputting target values and comprises a computer program for controlling the OCT scanning beam 21 and for adjusting the spatial extension and the position, i.e. the relative position and orientation, of the object region volume 22 scanned by the OCT scanning beam 21. The device 58 for controlling the OCT scanning beam 21 is embodied in this case for continuous scanning of the object region volume 22 and of the region of the section 84 of the object region volume 22 comprising the article 24 by means of the OCT scanning beam 21. In this case, the OCT scanning beam 21 has a frame rate of 10 to 20 ms in order to allow the surgeon to have fast hand-eye coordination.

[0082] The device 58 for controlling the OCT scanning beam 21 comprises a display unit 28 connected to the computer unit 60, which is in the form of a display for displaying a user interface on which the object region volume 22 with the section 84 of the article 24 scanned on the eye 14 of the patient by means of the OCT scanning beam 21 can be visualized on the basis of the image 64. Furthermore, in the arrangement 10, the OCT scanning information of the OCT device 20 can be visualized for the surgeon in the ocular lens 46 of the surgical microscope 16 by means of the device for superimposing data 34.

[0083] In addition, the computer unit 60 connected to the OCT device 20 generates an indication signal by means of the signal generator 30. In the case of the injection of stem cells, the indication signal generated as an acoustic signal is generated by means of the signal generator 30 when the injection position is reached. Furthermore, a variable in the form of the amount of stem cells still to be injected is generated on the basis of the visual indication signal, which is derived from the guidance variable.

[0084] Further, the computer program in the program memory of the computer unit 60 contains a control routine which specifies a reference length of the OCT scanning beam 21 and settings of the adjustable scanning mirrors 50, 52 for scanning an object volume 22 in the object region of the eye 14 of the patient. In the device 58 for setting the object volume 22 scanned by means of the OCT scanning beam 21 there is a control member 62 in the form of an operating unit which can be actuated by the operator. Furthermore, the control routine contains a scanning routine for scanning the object volume 22 and the section 84 of the article 24 using a specific scanning pattern. In this process, the object volume 22 is scanned at a lower rate than the section 84 of the article 24 in order to keep the amount of data as small as possible and thus the computation time as short as possible.

[0085] Furthermore, the computer program in the program memory of the computer unit 60 serves to determine a 3D reconstruction 94 of the object volume 22 and the relative position of the section 84 of the article 24 in the object volume 22 by processing the scanning information obtained by the OCT device 20 by scanning the object volume 22. In this case, the OCT scanning information, the 3D reconstruction 94 and the relative position of the section 84 of the article 24 in the object volume 22 are determined in real time. Furthermore, the computer program contains a calculation routine for determining a target region 90 in the 3D reconstruction 94 of the object volume 22. A guidance variable of the article 24 is determined which is related to the target region 90. Here, the guidance variable is understood in the present case to be a variable which is determined by the computer program and serves to guide the article 24 in the object region 18.

[0086] The occlusion of a region in the object volume 22 is avoided by means of a computer program which contains a path planning routine which calculates an optimal path of the article 24 to a spatial target position 91 in the target region 90 of the object volume 22 on the basis of certain criteria. In this case, the path planning routine determines an occlusion measure in the form of a value which quantifies the shadow present in the OCT data.

[0087] If the light source positions are known, the regions occluded by the article 24 in the OCT data are calculated in advance on the basis of the calculated relative position of the article 24 within a certain path of the article 24. In this case, the occlusion measure represents an occlusion value. On the basis of the occlusion measure, the path planning routine then determines the shortest path of the article 24 to the target position 91 which does not exceed a threshold value of the occlusion measure. Alternatively, the path planning routine minimizes a criterion of the sum of the path length and a weighted occlusion measure in order to determine a path which minimizes both the path length and the occlusion measure to the greatest possible extent. The computer program contains a visualization routine for visualizing the optimal path of the article 24 for the surgeon using the display unit 28. In this case, the path of the article 24 to the target region 90 represents the guidance variable.

[0088] It should be observed that the computer program can contain a masking routine for preventing masking of regions in the object volume 22, which identifies regions masked by the item 24 and specifies a compensation rule for the 3D reconstruction 94 of the object volume 22 in relation to these regions. In this case, the compensation rule prescribes a replacement of the masked regions.

[0089] OCT data of the same region at other recording times, in particular OCT data immediately before masking of the masked region, can be used both for identification and for replacement of the masked regions in the 3D reconstruction 94.

[0090] When stem cells are injected into the retina 15, a target value for the volume of the medium 88 in the form of the amount of stem cells to be released by the injection needle is determined as a guide variable.

[0091] Figure 2 is an enlarged view of the item 24 in the form of a surgical instrument.

[0092] The surgical instrument is an injection needle for injecting stem cells into the retina 15 of the eye 14 of the patient. The injection needle has a section 84 which acts as an active section and also has a handle section 76 which can be held by the surgeon or, as an alternative, by the micro robot 70. The injection needle contains a capillary 86 and has a tip 80 with an opening 82 for releasing the medium 88 into the target region 90. There is a marker 78 which can be located at the injection needle by means of the OCT scanning beam 21.

[0093] It should be observed that the surgical instrument can also be in the form of an applicator for a retinal needle to place an implant on the retina 15 of the eye 14 of the patient or as a glass knife to remove the vitreous humor from the eye 14 of the patient. It should furthermore be observed that, in principle, the arrangement 10 can also be used for surgical interventions on other body parts than the eye 14 of the patient.

[0094] Figure 3 The structure of the retina 15 of the eye 14 of the patient is shown, including blood vessels 108 and photoreceptors 112 and choroidal drusen 114.

[0095] Figure 4The transfer of the target region 90' based on the preoperatively determined data 92 to the 3D reconstruction 94 of the subject volume 22 in the computer unit 60 is shown. For determining the target region 90 and the target position 91 in the 3D reconstruction 94 of the subject volume 22, the preoperatively determined data 92 of the subject volume 18 and the target position 91'in the target region 90' are combined by a calculation in the 3D reconstruction. Here, the target position 91'represents a position in the preoperatively determined data 92 related to the subject volume 22, at which position the item 24 shall perform a certain function. When injecting stem cells, the intended position 91'in the target region 90' in the preoperatively determined data 92 corresponds to the intended position of the stem cell injection in the retina 15.

[0096] The method for segmenting tissue structures and tissue layers is applied for the purpose of determining the target position 91'and / or the target region 90' in the preoperatively determined data 92. Alternatively, the surgeon can also mark the target position 91'and / or the target region 90' in the preoperatively determined data 92.

[0097] The target position 91'and / or the target region 90' is transferred from the preoperatively determined data 92 of the subject volume 22 by a computer program to the 3D reconstruction 94 of the subject volume 22 determined from scanning information obtained by scanning the subject volume 22 and optionally from further data. In this case, a registration method is used for the transfer, which maps the target position 91'in the target region 90' in the preoperatively determined data 92 to the target position 91 in the target region 90 of the subject volume 22. Alternatively, the surgeon can also mark the target position 91 and / or the target region 90 directly in the 3D reconstruction 94 of the subject volume 22.

[0098] Then, a guidance variable is determined by processing the data of the target region 90' in the preoperatively determined data 92 or the data of the 3D reconstruction 94 of the subject volume 22. When injecting stem cells, the guidance variable is determined in the form of the amount of stem cells still to be released.

[0099] In this respect, Figure 5A and Figure 5B Each shows an OCT-B scan of the subject volume 22 with stem cells released at the target position 91 in the target region 90, wherein the OCT-B scan has an injection inhomogeneity.

[0100] To monitor and control the amount of injected stem cells, the actual volume of stem cells released at the target location 91 in the target region 90 of the target area volume 22 is determined by comparing OCT scan information of the target region 90 obtained by the OCT device 20 by scanning the target area volume 22 before and during stem cell release. In this case, the amount of injected stem cells is determined by means of image processing. To determine volume variations, for example, difference images can be evaluated as differences in OCT scan information items acquired at different times and / or differences in 3D reconstructions 94 determined at different times. If the amount of injected stem cells contains particles visible to OCT scan radiation, the difference images can also be used to determine leakage locations in the target area volume 22 by image processing. These measures take into account potential leakage and ensure that the specified amount of stem cells is actually injected at the injection site. If necessary, the injection site, i.e., the target location of the injection needle, can also be adjusted during stem cell injection.

[0101] Based on the target amount of stem cells to be injected specified by the surgeon, a guide variable, in the form of the amount of stem cells to be released, is determined according to the difference between the target amount and the determined actual amount. To readjust the stem cell amount, the computer program generates instruction signals for the surgeon and / or control signals for the injection needle, transmitting these control signals to the control unit 72 of the microrobot 70 that guides the injection needle until the specified amount of stem cells is obtained at the target location 91 in the target region 90.

[0102] In this scenario, signal generator 30 generates an instruction signal for the surgeon, specifying the amount of stem cells to be released or the amount already released. The instruction signal is displayed as a bar on the display unit 28. Based on this signal, the surgeon can either perform the stem cell injection themselves or monitor the injection procedure of the microrobot 70.

[0103] Figure 6 A second arrangement 10' is shown, comprising a surgical microscope 16, an OCT device 20 for scanning a target area 18, an article 24 in the form of a surgical instrument, and an image providing device 65. Figure 6 The components and elements of the second arrangement 10' shown in the diagram are similar to those in... Figure 1 The components and elements of the first arrangement 10 visible in the figure are identified with the same numbers as those in the accompanying drawings.

[0104] The image providing device 65 includes an image capturing device 66, by means of which images of the patient's eye 14 can be captured in real time. Alternatively, the image providing device 65 includes a memory 63, in which preoperatively determined data 92 related to the target area is provided. In addition to the data obtained by scanning the target area volume 22 using the OCT scanning beam 21 of the OCT device 20, the images of the patient's eye 14 and the preoperatively determined data 92 are used to calculate the 3D reconstruction 94 to obtain greater accuracy of the procedure. It should be observed that, in principle, biometric patient data, such as eye length, eye diameter, white-to-white ratio, corneal thickness, anterior chamber depth, or anterior chamber angle, can also be used when creating the 3D reconstruction 94 of the target area volume 22.

[0105] A registration method is used to determine the relative spatial position of different data with respect to each other and to combine different data sources. This registration method processes scan information obtained by the OCT device 20 by scanning the object volume 22, preoperatively determined data 92, the target position 91 of items 24, 24', and (if any) further data of the object volume 22. This allows all acquired data to be used synchronously in each visualization of the object volume 22.

[0106] Figure 7 A third arrangement 10 is shown, comprising a surgical microscope 16, an OCT device 20 for scanning a target area 18, an article 24 in the form of a surgical instrument, and a robotic unit 68. Figure 8 The components and elements of the third arrangement 10" shown in the figure are similar to those in the figure. Figure 1 The components and elements of the first arrangement 10 visible in the middle or in Figure 6 The components and elements of the second arrangement 10' visible in the figure are identified with the same numbers as those in the accompanying drawings.

[0107] Robotic unit 68 includes a microrobot 70 with a control unit 72. By way of example, the microrobot 70 may take the form of a manipulator for surgical instruments with motor drive, such as that provided in the ophthalmic surgical operating system R1.1 of Preceyes BV.

[0108] To ensure the most comprehensive automation possible, a microrobot 70 is used to control the movement of the article 24, which is a surgical instrument in the form of an injection needle. In this case, the microrobot 70 of the robot unit 68 is controlled based on information processed by the computer unit 60.

[0109] The control signal generated by computer unit 60 to adjust the microrobot 70 in robot unit 68 is the guiding variable of item 24, which, in the third arrangement 10", is embodied in the form of a surgical instrument, an injection needle.

[0110] It should be observed that, instead of the article 24 embodied in the form of a surgical instrument, which is an injection needle, the microrobot can also, in principle, move articles embodied in the form of an applicator, a retinal needle, or a glass scalpel to guide the article to a target region 90 within the object region volume 22. For this purpose, a computer program can calculate offset information based on the determined relative position of the target region 90 within the object region volume 22 and the article 24, specifying the spatial offset of segment 84 of the article 24 from the spatial target position 91. Then, control signals for displacing the article 24 are generated based on the offset information, and these control signals are transmitted to the control unit 72 of the microrobot 70.

[0111] Figure 8 A fourth arrangement 10"' is shown, comprising a surgical microscope 16, an OCT device 20 for scanning a target area 18, an article 24 in the form of a surgical instrument, a robotic unit 68, and an image providing device 65. Figure 9 The components and elements of the fourth arrangement 10"' shown in the diagram are related to those in... Figure 1 , Figure 6 and Figure 7 The components and elements of the arrangement 10, 10', 10" shown in and described based on these figures have been identified with the same numbers as those in the figures. In this case, the image providing device 65 with the image capturing device 66 is advantageous for calculating the 3D reconstruction 94 of the patient's eye 14 more accurately than 3D reconstruction based exclusively on the scan information obtained by means of the OCT device 20.

[0112] It should be observed that during vitrectomy using surgical instruments, which are also in the form of glass cutters, the amount of vitreous fluid to be removed from the corresponding point on the retina 15 can also be designated as a guiding variable in the arrangement described above.

[0113] Furthermore, it should be observed that if the surgical instrument is also in the form of a glass blade, the amount of vitreous fluid to be removed from the patient's eye 14 can also be indicated as a display signal in the arrangements 10, 10', 10" and 10"' described above.

[0114] Figure 9 Article 24 is shown, which is a surgical instrument in the form of an applicator for placing another article 24' in the form of a retinal needle for securing another article in the form of an implant to the retina 15.

[0115] Figure 10A and Figure 10B An implant for the retina 15 of the eye 14 of a patient is shown as an item 24, which comprises a power supply 116 with a photovoltaic assembly and an image capturing assembly 118. In this case, Figure 10A is a perspective view of the implant in the case where the viewing direction is directed to the side facing away from the retina. Figure 10B is a perspective view of the implant in the case where the viewing direction is on the side facing the retina of the eye 14 of the patient. Figure 10C is an enlarged partial view of the implant. The implant has 3D electrodes 120, which penetrate into the retina 15 and interact there with the neural network of the nerve tracts.

[0116] In the devices 10, 10', 10", 10"' described above, the target position 91 of the retinal needle to the envisaged position of the retina 15 of the eye of the patient and the actual position of the item 24 in the form of the implant on the retina 15 can be displayed on the display unit 28 to achieve the purpose of attaching the implant in the eye 14 of the patient.

[0117] Figure 11 A first image of the operating area in the interior of the eye of the patient 14 is shown, which was captured by means of a camera, which image comprises a first item 24 in the form of an applicator for a retinal needle and comprises a further item 24' in the form of an implant just before being placed on the retina 15. Figure 12 A corresponding image of the operating area with the implant after being placed on the retina 15 is shown. After the implant has been attached to the retina, the sitting point of the implant is verified by means of a check by the surgeon, for example, whether the implant fulfils its intended physiological function. When attaching the implant to the retina 15 of the eye 14 of the patient, a guidance variable in the form of a control signal is generated by the computer program for displacing the applicator for attaching the retinal needle for fastening the implant, and this guidance variable is transmitted to the control unit 72 of the surgeon or the micro robot 70.

[0118] Figure 13An image 106 of the fundus of the eye 14 of the patient is shown, which visualizes blood vessels based on OCT angiography data. In the above described arrangements 10, 10', 10", 10"' the corresponding OCT angiography data can be generated from scan information obtained by the OCT device 20 by scanning the object volume 22 and can be displayed on the display unit 28. The image 106 shows the course of blood vessels 108 in the object region 18. The position and / or size (such as diameter or length) of the blood vessels 108 is determined by the computer program based on the image 106 (based on OCT angiography data), e.g. by means of image processing. This information is then taken into account when determining the target position 91 of the item 24, 24' in the object volume 22 of the 3D reconstruction 94. In particular, the number of blood vessels 108 to be punctured is minimized when determining the spatial target position 91 of the item 24, 24' in the target region 90.

[0119] Figure 14 An image of the operating region in the interior of the eye 14 of the patient is shown, which is captured by means of a camera, with an implant and with blood flowing from the damaged blood vessels 108 on the retina 15 of the eye 14 of the patient.

[0120] The OCT angiography data from the scan information obtained by the OCT device 20 by scanning the object volume 22 allows to prevent bleeding 110 due to damaging relatively large blood vessels 108 in the case of ophthalmic surgical operations.

[0121] Figure 15 An image of the operating region in the interior of the eye 14 of the patient is shown, which is captured by means of a camera, with an item 24 in the form of a glass knife for a vitrectomy positioned in the operating region, thus obscuring a region 104 of the eye 14 of the patient. An accurate vitrectomy without residues is important for the success of a retinal implant surgery, as it facilitates an improved signal-to-noise ratio.

[0122] Therefore, for a vitrectomy by means of a glass knife in the context of an ophthalmic surgical operation, the target position 91 of the glass knife in the target region 90 can be displayed on the display unit 28 in the above described devices 10, 10', 10", 10"' as the position at which the vitreous humor should be removed in the 3D reconstruction 94 of the object volume 22.

[0123] Therefore, the computational routines of the computer program in the computer unit 60 arranged as 10, 10', 10", 10"' are designed to perform vitrectomy by means of a glass scalpel in such a way that the amount of vitreous fluid to be removed is determined as a guiding variable by processing the target region 90 in the 3D reconstruction 94 of the target region volume 22. Alternatively, the amount of vitreous fluid to be removed can also be determined by processing preoperatively determined data 92 or by a target value input by the surgeon. In this case, the amount of vitreous fluid to be removed is determined by injecting a triamcinolone acetonide marker (from... Figure 15 The vitreous fluid is clearly identified to facilitate more accurate identification and, where possible, removal without residue. In this case, the vitreous fluid to be removed is visualized to the surgeon based on a contour map, which indicates the amount of vitreous fluid to be removed at each point on the retina 15. Furthermore, during vitrectomy, the computer program continuously indicates to the surgeon the boundary between the vitreous fluid and the solution (BSS) used to irrigate the target area 18. Therefore, the amount of vitreous fluid to be removed can be automatically determined by image processing and displayed in the visualization of the operating area via a display unit.

[0124] Further guiding variables, in the form of control signals, are generated both during stem cell injection and during vitreous fluid removal to displace surgical instruments, in the form of injection needles or glass cutters, and these further guiding variables are transmitted to the control unit 72 of the surgeon or microrobot 70.

[0125] also, Figure 15 A region 104 within object volume 22 is shown, obscured by an object 24 in the form of a glass cutter. The computer program includes an occlusion routine for preventing occlusion of regions within object volume 22. This occlusion routine identifies regions 104 obscured by object 24 and specifies compensation rules for the 3D reconstruction 94 of object volume 22 for these regions. In this case, the compensation rules specify replacement for the obscured regions. OCT data of the same regions at other recording times, particularly OCT data just before the occlusion of the obscured region 104, can be used for both identification and replacement. Figure 15The shadowing routine for identifying shadowed regions and / or for specifying compensation rules can use the current 3D reconstruction 94 and / or the currently recorded OCT data and / or data from other modalities related to the same region, e.g. optical data, MRI data, ultrasound images or CT data, as an alternative. Data 92 determined prior to the operation can also be used. Alternatively, the shadowed regions 104 can also be detected in the 3D reconstruction 94 and can be replaced by data acquired from other regions outside the shadowed regions 104. Alternatively, the shadowed regions 104 can be detected in the data or in the 3D reconstruction 94 and can be replaced by data generated by a computer program, e.g. by inpainting methods.

[0126] Region shadowing can be avoided by means of a computer program containing a path planning routine which calculates an optimal path of the object 24 to a spatial target position 91 in the target region 90 of the object region volume 22 based on certain criteria. In this case, the path planning routine determines a shadowing measure in the form of a value which quantifies the shadows present in the OCT data. If the light source positions are known, the regions 104 shadowed by the object 24 in the OCT data are calculated in advance based on the calculated relative position of the object 24 within a certain path of the object 24. In this case, the shadowing measure represents the shadowing value. Based on the shadowing measure, the path planning routine then determines the shortest path of the object 24 to the target position 91 which does not exceed a threshold value of the shadowing measure. Alternatively, the path planning routine minimizes a criterion of the sum of the path length and a weighted shadowing measure in order to determine a path which minimizes both the path length and the shadowing measure to the greatest possible extent. The computer program contains a visualization routine for visualizing the optimal path of the object 24 for the surgeon using the display unit 28. In this case, the path planning of the object 24 to the target region 90 represents a guidance variable.

[0127] It should be observed that both the input data of the 3D reconstruction method and the input data of the registration method are adapted to the availability of the provided data and the measurement accuracy during the operation, if possible, in order to obtain greater accuracy of the 3D reconstruction 94 of the object region volume 22. If the measurement accuracy of individual data points is too low, the respective method does not take these data points into account.

[0128] In summary, particular attention is drawn to the following: The invention relates to an arrangement 10, 10', 10", 10"' comprising an OCT device 20 for scanning an object volume 22 arranged in an object region 18 by means of an OCT scanning beam 21, an article 24 having a section 84 in the object volume 22 which is arrangeable in the object region 18 and positionable in the object volume 22 by means of the OCT device 20, and a computer unit 60 connected to the OCT device 20 and containing a computer program for determining a 3D reconstruction 94 of the object volume 22 and determining a relative position of the section 84 of the article 24 in the object volume 22 by processing OCT scan information obtained by the OCT device 20 by scanning the object volume 22, wherein the computer program has a computing routine for determining a target region 90 in the 3D reconstruction 94 of the object volume 22, said computing routine determining a guidance variable of the article 24 in relation to the target region 90.

[0129] In particular, the invention relates to the following aspects specified in the clauses:

[0130] 1. An arrangement (10, 10', 10", 10"'),

[0131] comprising an OCT device (20) for scanning an object volume (22) in an object region (18) by means of an OCT scanning beam (21),

[0132] comprising an article (24, 24') having a section (84) in the object volume (22) which is arrangeable in the object region (18) and positionable in the object volume by means of the OCT device (20), and a computer unit (60) connected to the OCT device (20) and containing a computer program for determining a 3D reconstruction (94) of the object volume (22) and determining a relative position of the section (84) of the article (24, 24') in the object volume (22) by processing OCT scan information obtained by the OCT device (20) by scanning the object volume (22),

[0133] characterized in that

[0134] the computer program has a computing routine for determining a target region (90) in the 3D reconstruction (94) of the object volume (22), said computing routine determining a guidance variable of the article (24, 24') in relation to the target region (90).

[0135] 2. The arrangement (10, 10', 10", 10"') as claimed in clause 1, characterized in that

[0136] The computer program is designed to determine a 3D reconstruction (94) of the object volume (22) from data obtained by examining the object volume (22) using an imaging method, in particular by scanning the object volume (22) by means of an OCT scanning beam (21) of the OCT device (20), and / or from preoperatively determined data (92) and / or from data relating to sensor signals for determining the position of a section (84) of the item (24, 24') in the object volume (22);

[0137] and / or

[0138] The computer program is designed to determine the relative spatial position of data relative to one another by means of a registration method, said data comprising data from the following groups: scanning information obtained by means of the OCT device (20) by scanning the object volume (22), the object volume (22), data from further imaging methods, in particular optical image representations, MRI data, CT data, ultrasound images, endoscopic images, the position of a section (84) of the item (24), preoperatively determined data (92), position sensor signals;

[0139] and / or

[0140] The OCT device (20) is designed for continuous scanning of the object volume (22) by means of the OCT scanning beam (21) and / or the OCT device (20) is designed for continuous scanning of a region of the object volume (22) containing a section (84) of the item (24, 24') by means of the OCT scanning beam (21);

[0141] and / or

[0142] The computer program is designed for continuous determination of a 3D reconstruction (94) of the object volume (22) and / or for continuous determination of the relative position of a section (84) of the item (24, 24') in the object volume (22);

[0143] and / or

[0144] The computer program is designed to determine a spatial target position (91) of the item (24, 24') in the 3D reconstruction (94) of the object volume (22);

[0145] and / or

[0146] The computer unit (60) is connected to a memory (63) for providing preoperatively determined data (92) during the surgical procedure;

[0147] and / or

[0148] The computer program is designed to determine a target region (90') and / or a spatial target position (91') in the preoperatively determined data (92) and / or a target region (90) and / or a spatial target position (91) in the 3D reconstruction (94) of the object volume (22) by means of applying a method for segmenting tissue structures and / or tissue layers;

[0149] and / or

[0150] The computer program contains routines for generating a guidance variable in the form of a control signal for the item (24, 24');

[0151] and / or

[0152] The computer program is designed to determine a spatial target position (91) in the target region (90) in the 3D reconstruction (94) of the object volume (22) as a guidance variable taking into account characteristic features of the item (24) and / or of a further item (24') and / or of the target region (90) in the 3D reconstruction (94) of the object volume (22) and / or taking into account geometric relationships, in particular offset information, between these items;

[0153] and / or

[0154] The arrangement comprises means for visualizing a relative position of a section (84) of the item (24) in the 3D reconstruction (94) of the object volume (22) and / or for visualizing the preoperatively determined data (92) and / or for visualizing the determined guidance variable relating to the target region (90) and / or for visualizing variables derived from the guidance variable;

[0155] and / or

[0156] The computer program generates an acoustic, optical or haptic indication signal for a surgeon on the basis of the determined guidance variable relating to the target region (90) and / or variables derived from the guidance variable;

[0157] and / or

[0158] The computer program contains a masking routine for determining a corrected 3D reconstruction (94) of the object volume (22), which identifies regions (104) masked by the item (24, 24') and specifies compensation rules for the 3D reconstruction (94) of the object volume (22) relating to these regions;

[0159] and / or

[0160] Markers (78) positionable by the OCT scanning beam (21) are arranged in a section (84) of the item (24, 24') and / or in the object volume (18);

[0161] and / or

[0162] The computer program comprises a scanning routine for scanning the object volume (22) and / or the segment (84) of the item (24, 24') using a specific scanning pattern and / or for adjusting the scanning rate, i.e. scanning the object volume (22) at a lower rate compared to the position of the segment (84) of the item (24, 24').

[0163] and / or

[0164] The computer program is designed to adjust the determination rules of the 3D reconstruction (94) and / or the determination rules of the relative position of the segment (84) of the item (24, 24') in the object volume (22) based on certain criteria.

[0165] 3. The arrangement (10, 10', 10", 10'") according to clause 1 or 2, characterized in that OCT angiography data (106) of the object volume (22) is generated from the scanning information obtained by scanning the object volume (22) by means of the OCT device (20).

[0166] 4. The arrangement (10, 10', 10", 10'") according to clause 3, characterized in that the computer program is designed to determine the position and / or size of blood vessels (108) in the target region (90) based on the OCT angiography data (106), and the calculation routine of the computer program is used to determine the target region (90) in the 3D reconstruction (94) of the object volume (22) taking into account the course and / or position and / or size of the blood vessels (108) in the target region (90).

[0167] 5. The arrangement (10, 10', 10", 10'") according to any one of clauses 1 to 4, characterized in that the computer program comprises a path planning routine which calculates an optimal path of the item (24, 24') to the spatial target position (91) based on certain criteria.

[0168] 6. The arrangement (10, 10', 10", 10'") according to clause 5, characterized in that the criteria is a shadowing measure which quantifies the shadows caused by the item (24, 24') present in the calculated 3D reconstruction (94).

[0169] 7. The arrangement (10, 10', 10", 10"') according to any one of claims 1 to 6, characterized in that the computer program contains routines for determining a target region (90') and / or a target position (91') of the object (24) in the provided preoperatively determined data (92) and has a registration routine for registering the preoperatively determined data (92) with the 3D reconstruction (94) of the object volume (22) and a transfer routine for transferring the target region (90') and / or the target position (91') in the preoperatively determined data (92) to the 3D reconstruction (94) of the object volume (22).

[0170] 8. The arrangement (10, 10', 10", 10"') according to any one of claims 1 to 7, characterized in that the object (24, 24') is in the form of a surgical instrument comprising a capillary tube (86) having an opening (82) for releasing a medium (88).

[0171] 9. The arrangement (10, 10', 10", 10"') according to claim 8, characterized in that the calculation routines of the computer program are for determining a target value for the volume of the released medium (88) as a guiding variable by processing the target region (90) in the 3D reconstruction (94) of the object volume (22) and / or by processing the preoperatively determined data (92) and / or by processing OCT scan information obtained by scanning the object volume (22) by means of the OCT device (20) and / or by inputting a target value by the surgeon.

[0172] 10. The arrangement (10, 10', 10", 10"') according to claim 8 or 9, characterized in that the calculation routines of the computer program are for determining an actual value for the volume of the medium (88) released into the target region (90) by comparing data of the target region (90) in the 3D reconstruction (94) of the object volume (22) before and during the release of the medium (88) and / or by scan information of the target region (90) obtained by scanning the object volume (22) by means of the OCT device (20).

[0173] 11. The arrangement according to any one of claims 8 to 10, characterized in that the calculation routines of the computer program are designed to determine a difference between a target value and an actual value for the volume of the medium (88) released into the target region (90) as a guiding variable for readjusting the volume of the released medium (88).

[0174] 12. The arrangement as described in any one of Clauses 1 to 7, characterized in that the computational routine of the computer program is used as a guiding variable to determine the location and / or amount of material to be removed by processing the target region (90) in the 3D reconstruction (94) of the object region volume (22) and / or by processing preoperatively determined data (92) and / or by using target values ​​input by the surgeon.

[0175] 13. The arrangement (10, 10', 10", 10"') as described in Clause 12 is characterized by a visualization routine for visualizing the location and / or amount of the substance to be removed in the object area volume (22).

[0176] 14. A computer program for determining a 3D reconstruction (94) of the object region volume (22) in an object region (18) by processing OCT scan information obtained by means of an OCT device (20) through scanning the object region volume (22) and determining the relative positions of segments (84) of an article (24) in the object region volume (22).

[0177] Its features are,

[0178] Determine the target region (90) in the 3D reconstruction (94) of the object region volume (22) and the guiding variables of the item (24) related to the target region (90).

[0179] 15. A method for determining a 3D reconstruction (94) of an object region volume (22) in an object region (18) by means of a computer program as described in Clause 14 and for determining the relative position of a segment (84) of an article (24) in the object region volume (22).

[0180] List of reference signs

[0181] 10, 10', 10", 10"' Layout / Equipment

[0182] 12. Cornea

[0183] 14. The patient's eyes

[0184] 15. Retina

[0185] 16. Surgical microscope

[0186] 18 Object Area

[0187] 20 OCT devices

[0188] 21 OCT scanning beam

[0189] 22. Object region volume

[0190] 24, 24' article

[0191] 26 optical axis

[0192] 28 display unit

[0193] 30 signal generator

[0194] 34 data superimposition

[0195] 38, 40 stereoscopic observation beam path

[0196] 42 microscope main objective

[0197] 44 zoom system

[0198] 46 eyepiece

[0199] 48 illumination device

[0200] 50, 52 scanning mirror

[0201] 54, 56 beam splitter

[0202] 58 device

[0203] 60 computer unit

[0204] 61 input interface

[0205] 62 control member

[0206] 63 memory

[0207] 64 image

[0208] 65 image providing device

[0209] 66 image capturing device

[0210] 68 robot unit

[0211] 70 microrobot

[0212] 72 control unit

[0213] 76 handle section

[0214] 78 marker

[0215] 80 tip

[0216] 82 opening

[0217] 84 section

[0218] 86 capillary

[0219] 88 medium

[0220] 90 target region

[0221] 90' target region in preoperatively determined data

[0222] 91 target location

[0223] 91' target location in preoperatively determined data

[0224] 92 preoperatively determined data

[0225] 94 3D reconstruction

[0226] 104 shadowed area

[0227] 106 image based on OCT angiography data

[0228] 108 blood vessel

[0229] 110 hemorrhage

[0230] 112 photoreceptor

[0231] 114 drusen

[0232] 116 power source

[0233] 118 image capture component

[0234] 120 3D electrode

Claims

1. A system (10, 10', 10", 10"') comprising an OCT device (20) for scanning an object volume (22) in an object region (18) by means of an OCT scanning beam (21); an article (24, 24') having a section (84) which can be arranged in the object volume (22) and can be positioned in the object volume by means of the OCT device (20), and a computer unit (60) connected to the OCT device (20) and containing a computer program for determining a 3D reconstruction (94) of the object volume (22) by processing OCT scanning information obtained by scanning the object volume (22) by means of the OCT device (20) and for determining a relative position of the section (84) of the article (24, 24') in the object volume (22), characterized in that the computer program has a calculation routine for determining a target region (90) in the 3D reconstruction (94) of the object volume (22), which calculation routine determines a guidance variable of the article (24, 24') in relation to the target region (90), the computer program contains a path planning routine for calculating an optimal path of the article (24, 24') to a spatial target position (91) on the basis of a certain criterion, and the criterion is a shadowing measure which quantifies shadows caused by the article (24, 24') present in the calculated 3D reconstruction (94). the computer program is designed to determine the 3D reconstruction (94) of the object volume (22) from data obtained by examining the object volume (22) using an imaging method, and / or from preoperatively determined data (92) and / or from data relating to sensor signals for determining the position of the section (84) of the article (24, 24') in the object volume (22).

2. The system (10, 10', 10", 10"') as claimed in claim 1, characterized in that, the computer program is designed to determine the 3D reconstruction (94) of the object volume (22) from data obtained by scanning the object volume (22) by means of the OCT scanning beam (21) of the OCT device (20).

3. The system (10, 10', 10", 10"') as claimed in claim 1, characterized in that, the computer program is designed to determine the relative spatial position of data relative to one another by means of a registration method, said data comprising data from the following group: scanning information obtained by scanning the object volume (22) by means of the OCT device (20), the object volume (22), data from a further imaging method.

4. The system (10, 10', 10", 10"') according to any one of claims 1 to 3, characterized in that, the group comprises: optical image representations, MRI data, CT data, ultrasound images, endoscopic images, the position of the section (84) of the article (24), preoperatively determined data (92), position sensor signals.

5. The system of claim 4, wherein, 6. The system as claimed in any one of claims 1 to 3, characterized in that ​ The OCT device (20) is designed for continuous scanning of the object volume (22) by means of the OCT scanning beam (21) and / or the OCT device (20) is designed for continuous scanning of a region of the object volume (22) containing a section (84) of the object (24, 24') by means of the OCT scanning beam (21); and / or The computer program is designed for continuous determination of a 3D reconstruction (94) of the object volume (22) and / or for continuous determination of the relative position of a section (84) of the object (24, 24') in the object volume (22); and / or The computer program is designed to determine a spatial target position (91) of the object (24, 24') in a 3D reconstruction (94) of the object volume (22); and / or The computer unit (60) is connected to a memory (63) for providing preoperatively determined data (92) during a surgical operation; and / or The computer program is designed to determine a target region (90') and / or a spatial target position (91') in the preoperatively determined data (92) and / or a target region (90) and / or a spatial target position (91) in a 3D reconstruction (94) of the object volume (22) by means of applying a method for segmenting tissue structures and / or tissue layers; and / or The computer program contains routines for generating a guidance variable in the form of a control signal for the object (24, 24'); and / or The computer program is designed to determine a spatial target position (91) in a target region (90) in a 3D reconstruction (94) of the object volume (22) as a guidance variable taking into account the characteristic features of the object (24) and / or of a further object (24') and / or of the target region (90) in the 3D reconstruction (94) of the object volume (22) and / or taking into account the geometrical relationships between these items; and / or The system comprises means for visualizing the relative position of a section (84) of the object (24) in a 3D reconstruction (94) of the object volume (22) and / or for visualizing the preoperatively determined data (92) and / or for visualizing the determined guidance variable relating to the target region (90) and / or for visualizing variables derived from the guidance variable; and / or The computer program generates acoustic, optical or haptic indication signals for a surgeon on the basis of the determined guidance variable relating to the target region (90) and / or variables derived from the guidance variable; and / or The computer program contains a masking routine for determining a corrected 3D reconstruction (94) of the object volume (22), which identifies regions (104) masked by the object (24, 24') and which specifies compensation rules for the 3D reconstruction (94) of the object volume (22) relating to these regions; and / or The computer program contains a masking routine for determining a corrected 3D reconstruction (94) of the object volume (22), which identifies regions (104) masked by the object (24, 24') and which specifies compensation rules for the 3D reconstruction (94) of the object volume (22) relating to these regions; Markers (78) locatable by the OCT scanning beam (21) are arranged in a section (84) of the object (24, 24') and / or in the object region (18); and / or The computer program contains a scanning routine for scanning the object region volume (22) and / or the section (84) of the object (24, 24') using a specific scanning pattern and / or for adjusting the scanning rate, i.e. scanning the object region volume (22) at a lower rate in comparison to the position of the section (84) of the object (24, 24'); and / or The computer program is designed to adjust the determination rules of the 3D reconstruction (94) and / or of the relative position of the section (84) of the object (24, 24') in the object region volume (22) based on certain criteria.

7. The system of any one of claims 1 to 3, wherein, The computer program is designed to determine a spatial target position (91) in the target region (90) in the 3D reconstruction (94) of the object region volume (22) as a guiding variable taking into account characteristic features of the object (24) and / or of a further object (24') and / or of the target region (90) in the 3D reconstruction (94) of the object region volume (22) and / or taking into account offset information between these items.

8. The system (10, 10', 10", 10"') according to any one of claims 1 to 3, characterized in that, OCT angiography data of the object region volume (22) are generated from the scanning information obtained by scanning the object region volume (22) by means of the OCT device (20).

9. The system (10, 10', 10", 10"') as claimed in claim 8, characterized in that, The computer program is designed to determine the position and / or size of blood vessels (108) in the target region (90) based on the OCT angiography data, the computing routine of the computer program being used to determine the target region (90) in the 3D reconstruction (94) of the object region volume (22) taking into account the course and / or position and / or size of the blood vessels (108) in the target region (90).

10. The system (10, 10', 10", 10"') as claimed in any of claims 1 to 3, characterized in that The computer program contains a routine for determining a target region (90') and / or a target position (91') of the object (24) in the provided preoperatively determined data (92) and has a registration routine for registering the preoperatively determined data (92) with the 3D reconstruction (94) of the object region volume (22) and a transfer routine for transferring the target region (90') and / or the target position (91') in the preoperatively determined data (92) to the 3D reconstruction (94) of the object region volume (22).

11. The system (10, 10', 10", 10"') according to any one of claims 1 to 3, characterized in that, The object (24, 24') is in the form of a surgical instrument comprising a capillary (86) having an opening (82) for releasing a medium (88).

12. The system (10, 10', 10", 10"') as claimed in claim 11, characterized by The computing routine of the computer program is used to determine a target value for the volume of the released medium (88) as a guiding variable by processing the target region (90) in the 3D reconstruction (94) of the object region volume (22) and / or by processing the preoperatively determined data (92) and / or by processing OCT scanning information obtained by scanning the object region volume (22) by means of the OCT device (20) and / or by inputting a target value by a surgeon.

13. The system (10, 10', 10", 10"') as claimed in claim 11, characterized by The calculation routine of the computer program serves to determine the actual value of the volume of the medium (88) released into the target region (90) by comparing data of the target region (90) in the 3D reconstruction (94) of the object volume (22) before and during the release of the medium (88) and / or by means of scan information of the target region (90) obtained by scanning the object volume (22) by means of the OCT device (20).

14. The system of claim 11, wherein, The calculation routine of the computer program is designed to determine the difference between the target value and the actual value of the volume of the medium (88) released into the target region (90) as a guiding variable for readjusting the volume of the released medium (88).

15. The system of any one of claims 1 to 3, wherein, The calculation routine of the computer program serves to determine the position of the substance to be removed and / or the amount of substance to be removed as a guiding variable by processing the target region (90) in the 3D reconstruction (94) of the object volume (22) and / or by processing preoperatively determined data (92) and / or by inputting a target value by the surgeon.

16. The system (10, 10', 10", 10"') as claimed in claim 15, characterized by A visualization routine serves to visualize the position of the substance to be removed in the object volume (22) and / or the amount of substance to be removed.

17. A computer program product for determining a 3D reconstruction (94) of an object volume (22) and determining a relative position of a section (84) of an article (24) in the object volume (22) by processing OCT scan information obtained by scanning an object volume (22) in an object region (18) by means of an OCT device (20), characterized in that a calculation routine serves to determine a target region (90) in the 3D reconstruction (94) of the object volume (22) and a guiding variable of the article (24) in relation to the target region (90), and a path planning routine calculates an optimal path of the article (24, 24') to a spatial target position (91) on the basis of a certain criterion, the criterion being a shadowing measure quantifying a shadow caused by the article (24, 24') present in the calculated 3D reconstruction (94).

18. A method of calculating an optimal path of an article to a spatial target position by a computer unit serving to determine a 3D reconstruction (94) of an object volume (22) and determining a relative position of a section (84) of an article (24) in the object volume (22) by processing OCT scan information obtained by scanning an object volume (22) in an object region (18) by means of an OCT device (20), characterized in that a target region (90) in the 3D reconstruction (94) of the object volume (22) and a guiding variable of the article (24) in relation to the target region (90) are determined, an optimal path of the article (24, 24') to a spatial target position (91) is calculated on the basis of a certain criterion, the criterion being a shadowing measure quantifying a shadow caused by the article (24, 24') present in the calculated 3D reconstruction (94).

Images