Method and system for creating a navigation plan for a catheter using a robot

Abstract

The present invention relates to a method for creating a navigation plan for a catheter in a tissue based on a limit value distribution, the method comprising the following steps: detecting first elasticity data of the tissue by means of a first imaging mode; reading first image data and associating the first elasticity data with the first image data; determining the limit value distribution at least based on the first elasticity data and associating the limit value distribution with the first image data; creating a navigation plan for the catheter in the tissue based at least on the first image data and the limit value distribution. The present invention also relates to a robot for navigating a catheter into a target area of ​​the tissue of a medical target object, and a system comprising a robot according to the present invention, a first imaging mode and / or a second imaging mode, and a computing unit, the computing unit being configured to create a navigation plan according to the method according to the present invention.

Description

Technical Field

[0001] The present invention relates to a method for creating a navigation plan for a catheter in tissue based on a limit value distribution; a robot for navigating a catheter into a target area of ​​tissue of a medical target object based on the navigation plan; and a system comprising a robot, a first imaging mode and / or a second imaging mode; and a computing unit configured to determine the limit value distribution and create a navigation plan based on at least first elasticity data and first image data. Background Art

[0002] In many cases, it is necessary to orient a medical object very accurately relative to a medical target object. Such a medical target object can be, for example, a patient or a patient simulator, also referred to as a dummy, for simulating the patient. The medical object, in particular a catheter or a needle, can be introduced into the medical target object, for example.

[0003] In particular, in the case of a catheter, the medical target object should be oriented according to a navigation plan created in advance. The navigation plan can, for example, include a path or a trajectory on which the medical object is oriented and / or moves. Such a navigation plan can, for example, be planned in advance based on information about the medical target object. For example, such information can be based on image data of an imaging mode of the medical target object, such as an ultrasound device, an X-ray device, a computer tomography device or a magnetic resonance device. In a specific example, it can be proposed that the catheter is guided to a target area in a patient or a dummy. As described above, the catheter is guided here in particular along a predetermined path or trajectory of the navigation plan.

[0004] The target area in the patient's body can be, for example, a tumor, a hematoma or an aneurysm. However, in many other cases, it is also necessary to accurately locate the medical object.

[0005] The catheter can be guided or navigated using a so-called guidance unit. The guidance unit can be designed to transmit a three-dimensional movement to the catheter or the needle in order to be able to navigate the catheter or the needle in the medical object. The guidance unit can be connected to a special robot or an imaging modality, for example. It is particularly conceivable that the guidance unit is controlled by an operator, for example a surgeon, in order to navigate the catheter or the needle into a target area of ​​the medical target object. The operator of the guidance unit can in particular use real-time image data of the imaging modality and the navigation plan.

[0006] Although the navigation plan can be created based on the image data using conventional methods, it is not always possible to avoid complications when navigating a catheter in a medical target object. Complications include, for example, damage to the vessel wall caused by the catheter, rupture of an aneurysm, or detachment of a thrombus on the vessel wall. Conventional methods for creating navigation plans are not sufficient to solve these problems, since the operator must have a lot of experience with the robot, in particular, in order to be able to assess the load on the tissue. Summary of the invention

[0007] It is therefore an object of the present invention to provide a method, robot, system and computer program product that improve navigation planning and reduce the risk of complications when navigating a catheter in a medical target object.

[0008] The object is achieved by the method, robot, system and computer program according to the invention. Advantageous embodiments and expedient developments are described below.

[0009] In the method according to the invention, a navigation plan is created for a catheter in tissue based on a limit value distribution which comprises spatially resolved limit values ​​for the maximum force absorption and / or the permitted deflection of a volume element of the tissue.

[0010] The navigation plan can include multidimensional information (tissue information) about the tissue of the medical target object and the positioning instructions for the catheter at this time. The tissue can include, for example, the skin, organs, blood vessels or sections of any body region of the patient. The tissue information can be, for example, contrast, elasticity value, maximum force absorption, allowed deflection, density, tissue type, risk factors for rupture or can be any other instructions that determine tissue characteristics and / or are important for the navigation of the catheter in the tissue. The positioning instructions can include, for example, a direction vector or a series of direction vectors, which describe the path of the catheter through the tissue, such as the patient's vascular tree. It is also conceivable that the positioning instructions have multiple two-dimensional or three-dimensional coordinates, which can be transmitted to the guidance unit for guiding the catheter. The navigation plan preferably includes spatially resolved tissue information at this time. This spatially resolved tissue information can be, for example, the contrast of magnetic resonance measurement, computer tomography measurement, ultrasound measurement and / or X-ray measurement of the anatomical structure of the tissue. Preferably, the spatially resolved contrast is associated with other tissue information, such as the maximum force absorption and / or allowed deflection of the volume element of the tissue. Thus, a multidimensional virtual image of the tissue can be obtained, which is present, for example, as a plurality of vectors, matrices or a plurality of tuples. The maximum force absorption is preferably the magnitude of the force that can be applied to the volume element of the tissue without damaging the tissue. The allowed deflection of the volume element of the tissue can be an elastic movement of the tissue, after which the tissue can return to its initial position without damage. The tissue can be a blood vessel or a blood vessel wall, but can also be an organ.

[0011] In one step of the method, first elastic data of the tissue are detected by means of a first imaging mode, wherein the first elastic data include spatially resolved elastic values ​​of a volume element of the tissue. The imaging mode can be the following medical device, which is suitable for performing an imaging method spatially resolved for detecting image data and / or recording arbitrary, spatially resolved measurement values ​​of the tissue. The first imaging mode can be, for example, a magnetic resonance device, an ultrasound device or a 3D ultrasound device. It is conceivable that, although the first elastic data are recorded by means of an imaging mode, image data of the anatomical structure is avoided when detecting the first elastic data. The first imaging mode is particularly designed to perform elastic imaging measurements, wherein the elastic data of the tissue is detected. In this case, the tissue can be stimulated, for example, by means of sound waves, pressure waves and / or static or periodic compression, which cause compaction, movement and / or time-dependent vibration in the tissue. Similarly, targeted palpation or measurement of blood vessel and tissue deformation by catheters, robot catheters and / or other measuring instruments can be a feasible method for determining elastic values. Regions of tissues with different elastic properties can react differently to stimulation and can be distinguished when detecting the first elastic data.

[0012] The first elasticity data include the spatially resolved elasticity values ​​of the volume element of the tissue. This can mean that the measured elasticity values ​​are associated with coordinate or position information in the tissue, for example in the form of a tuple, a vector or a matrix. Possible measurement methods are, for example, magnetic resonance elastography and ultrasound-based shear wave elastography and compression elastography. Preferably, the first elasticity data include the elasticity values ​​of the following section of the blood vessel, the section including the path of the catheter through the blood vessel from the starting point to the target area. The starting point here can be an opening at the artery or vein of the medical examination object. The target area can be, for example, a hematoma, a tumor, an aneurysm, etc. in a blood vessel or an organ near a blood vessel.

[0013] In another step of the method according to the invention, the first image data are read and the first elasticity data are associated with the first image data, wherein the elasticity value of the volume element of the tissue is assigned to the volume element of the tissue of the first image data. The first image data can have a spatially resolved contrast of the anatomical structure in the tissue of the medical target object. The contrast can be, for example, a grayscale value of the volume element, which encodes spatially resolved tissue information, such as the density or proton content of the volume element. It is conceivable that the first elasticity data and the first image data are based on a common coordinate system, so that the elasticity value of the volume element can be associated with the corresponding contrast of the volume element according to the coordinates. It is also conceivable that the first image data is associated with the first elasticity data by means of an image registration method. Examples of such image registration methods are area-based and feature-based methods, such as based on correlation, pattern recognition, (Fourier) transformation, correspondence of control points, and models based on rigidity or elasticity.

[0014] When associating, the elasticity values ​​and grayscale values ​​of the volume element can be saved, for example, as a tuple, a vector or a matrix. It is also conceivable that the elasticity values ​​and grayscale values ​​of the volume element exist separately from each other and are assigned via a common mark or identifier. The spatial resolution of the first elasticity data can be different from the spatial resolution of the first image data. It is therefore conceivable that the first image data has a higher spatial resolution, so that the elasticity values ​​of the first elasticity data are associated with multiple volume elements of the first image data. However, it is also conceivable that the first elasticity data has a higher spatial resolution than the first image data, or that the spatial resolution of the first elasticity data coincides with the resolution of the first image data.

[0015] Preferably, the first image data include spatially resolved contrast of anatomical structures in the tissue of the medical target object. In particular, the first image data include the contrast of a section of the tissue that includes the path of the catheter through the blood vessel from the starting point to the target region.

[0016] Reading the first image data can mean: obtaining the first image data from a database, a local memory, a cloud memory, a server and / or a control unit of the imaging modality. It is conceivable that the first image data also include patient information. Such patient information can include demographic information, such as age, height, weight or gender, and treatment data, such as treatment history, medical history and / or information about known intolerances. It is also conceivable that the target area and / or other anatomical structures that are important for creating the navigation plan are already compared in the first image data.

[0017] In another step of the method according to the invention, the limit value distribution is determined at least according to the first elasticity data and associated with the first image data, wherein the limit values ​​of the volume element of the tissue are assigned to the volume element of the tissue of the first image data. The limit value distribution includes the spatially resolved limit values ​​of the maximum force absorption and / or the allowed deflection of the tissue volume element. It is conceivable that the limit value distribution is determined according to the first elasticity data. In this case, the spatially resolved limit values ​​of the limit value distribution can be associated with the coordinates and / or position information of the first elasticity data. It is also conceivable that the limit value distribution is determined according to the first elasticity data and the tissue information of the first image data. The coordinates and / or position information of the spatially resolved limit values ​​can be generated from the correlation of the contrast of the first elasticity value with the first image data. The limit value distribution can exist in the form of a tuple, a vector or a matrix, wherein each limit value of the volume element is associated with the coordinates and / or position information in the medical target object. In addition, it is conceivable that the limit values ​​of the volume element can be associated with the corresponding elasticity value of the first elasticity data and / or the corresponding gray value of the first image data by means of a mark or identifier.

[0018] The spatial resolution of the limit value distribution can correspond to the spatial resolution of the first elasticity data and / or the second elasticity data. In particular, the spatial resolution of the limit value distribution can correspond to a lower spatial resolution of the first image data or the first elasticity data.

[0019] For example, the maximum force absorption and / or the permissible deflection of the tissue can be determined based on a typical fatigue characteristic value of the tissue or a typical characteristic value of the tissue. Such a fatigue characteristic value or characteristic value can, for example, indicate an area-dependent force effect, above which the tissue may rupture. Preferably, the limit value of the volume element of the tissue is determined such that a safety distance from the maximum force absorption and / or the permissible deflection is taken into account.

[0020] In one step of the method according to the invention, a navigation plan for a catheter in a tissue is created based at least on the first image data and the limit value distribution. As described above, the navigation plan can include multidimensional tissue information of a medical target object and / or positioning instructions for a catheter in the tissue. The creation of the navigation plan can, for example, include the creation of a matrix having at least limit values ​​and contrasts associated with the coordinates and / or position information of the corresponding volume element of the tissue. For this purpose, for example, the limit values ​​and contrasts can be stored as vectors and associated with corresponding vectors having the coordinates and / or position information of the volume element. However, it is also conceivable that the limit values ​​and contrasts are assigned to the coordinates and / or position information in the form of tuples. In addition, the first image data and the limit value distribution can exist in the form of a k-space matrix and can be converted into a three-dimensional imaging of the tissue by means of a transformation, such as a Fourier transform.

[0021] The creation of the positioning instructions of the catheter can, for example, include information related to the direction of the maximum force absorption and / or the allowed deflection of the volume element of the tissue. In one example, at least one elastic value and the type, position, orientation and / or material composition of the volume element of the tissue can be used to predict the reaction of the tissue under the force applied by the catheter. The volume element of the tissue is preferably a section of the vessel wall that is deformed by contact with the catheter. For example, the deformation of the vessel wall can be determined based on the elastic value of the vessel wall and the volume element of the adjacent tissue and the assumed or predetermined direction of the force applied by the catheter. It is conceivable that the creation of the navigation plan includes the creation of a path for the catheter to pass through the vessel or vessel tree, which avoids exceeding the maximum force absorption and / or the allowed deflection along the path through the vessel tree. Based on the path, the positioning instructions can be derived, which can be transmitted to the computing unit or the guiding unit of the robot, for example. The positioning instructions can, for example, include a series of coordinates and / or direction vectors, which are converted into the movement of the catheter by means of the guiding unit.

[0022] It is also conceivable that the maximum force absorption and / or the permitted deflection of the vessel wall along the path of the vessel or the vessel tree is output together with the first image data by means of the navigation plan and transmitted to the display unit. The maximum force absorption and / or the permitted deflection of the vessel wall can be converted into a color value by means of a function, which can be displayed on the display unit.

[0023] By creating a navigation plan based on the limit value distribution, the risk of complications when navigating a catheter into a target area of ​​a medical target object can be reduced in an advantageous manner.

[0024] In a possible embodiment of the method according to the invention, first image data of the tissue are detected by means of a first imaging mode and / or a second imaging mode. The second imaging mode can be, for example, a magnetic resonance device, a computer tomography device, an ultrasound device, an X-ray device, etc. The second imaging mode can be an imaging mode different from the first imaging mode. In one example, the first imaging mode can be a magnetic resonance device and the second imaging mode can be an ultrasound device. It is conceivable that when detecting the first image data, the spatially resolved contrast of the anatomical structure in the tissue of the medical target object is recorded and stored in a database. It is also conceivable that the detection of the first image data is performed before or simultaneously with the detection of the first elasticity data in time. Before in time can mean that the detection of the first image data is performed weeks, days, hours or minutes before the detection of the first elasticity data. The simultaneous detection of the first image data and the first elasticity data can mean that the detection time period of the first elasticity data and the detection time period of the first image data overlap at least partially in time. Preferably, the first image data is recorded immediately before the detection of the first elasticity data or the determination of the limit value distribution, wherein the medical target object stays in a predetermined relative position relative to the first imaging mode and / or the second imaging mode.

[0025] By timely detecting the first image data and the first elasticity data, the relative position between the medical target object and the first imaging mode and / or the second imaging mode can be kept constant in an advantageous manner when creating a navigation plan. Therefore, the correlation between the contrast of the first image data and the elasticity value of the first elasticity data can be advantageously simplified. In addition, when the first image data is detected in a timely manner and a navigation plan is created, the current state of the medical target object can be detected, thereby reducing the risk of complications caused by unexpected pathological structures along the planned path.

[0026] In another embodiment of the method according to the invention, during the detection of the first image data, the parameter set of the first imaging mode and / or the second imaging mode is selected so that deposits are detected in the blood vessels of the tissue, wherein a navigation plan is created based on the information about the deposits in the blood vessels. The parameter set can include, for example, a plurality of imaging parameters of the first imaging mode and / or the second imaging mode, by means of which the contrast, resolution, imaging area, recording duration, etc. can be set. Examples of such imaging parameters of a magnetic resonance device are: T1 and / or T2 relaxation time, slice thickness, movement speed of the medical target object relative to the magnetic resonance device, imaging sequence, etc. The imaging parameters of an X-ray device can include the radiation dose, voltage and / or current of the X-ray tube, the quality of the radiation focus, the use and quality of the X-ray filter, the distance of the medical target object from the X-ray source, etc. In addition, in addition to the imaging modes mentioned, other imaging modes can also be used, such as a computer tomography device or an ultrasound device and / or other imaging parameters known to those skilled in the art.

[0027] The deposit can be, for example, a thrombus, an atherosclerotic plaque, etc. The deposit can be, for example, positioned on the inner side of the vessel wall and can be different from the surrounding tissue in composition. The composition of the deposit is preferably distinguished from the surrounding tissue in the following manner: the contrast of the volume element of the deposit in the first image data can be set by means of adjusting the parameter set of the first imaging mode and / or the second imaging mode. The atherosclerotic plaque can, for example, have a high component of calcium phosphate. By setting a parameter set that takes into account the high component of calcium phosphate, the contrast of the atherosclerotic plaque can be increased accordingly. In the example of magnetic resonance measurement, a plurality of differently weighted imaging sequences can be used to increase (for example, via a gradient echo sequence) or reduce (for example, via a spin echo sequence) the signal intensity of the blood relative to the deposit. It is also conceivable to use computed tomography angiography and / or color-coded Doppler ultrasound angiography with corresponding parameter sets known to those skilled in the art. It is also conceivable that the medical target object obtains a contrast agent before detecting the first image data, which increases the contrast of the deposit, blood or the tissue surrounding the deposit in the first image data. Preferably, the sediment is registered in the navigation project. This can mean that the contrast of the sediment is superimposed and / or merged with the corresponding contrast of the first image data of the navigation project based on its position information and / or coordinates.

[0028] By detecting deposits in the vessel tree by adjusting the parameter set of the first imaging mode and / or the second imaging mode, information about pathological conditions of the medical target object that are important for navigation of the catheter can be output in an advantageous manner together with the navigation plan and / or taken into account when creating the navigation plan. Based on the output of the deposits, the path of the catheter in the vessel can be adjusted in an advantageous manner and the risk of stroke due to the deposits being dislodged by contact with the catheter can be reduced.

[0029] According to another embodiment of the method according to the invention, when detecting the first image data, the parameter set of the first imaging mode and / or the second imaging mode is selected so that the position of the fluid accumulation in the tissue is determined, wherein the navigation plan is created based on the information about the fluid accumulation in the tissue. The fluid accumulation can be, for example, a vascular aneurysm or a hematoma on the vessel wall. The parameter set of the first imaging mode and / or the second imaging mode can be adjusted as described above so that an increased contrast of the fluid accumulation in the tissue of the medical target object can be detected. The tissue can in particular be a vascular tree. In one example, the first imaging mode is a magnetic resonance device, wherein the parameter set can include a spin echo sequence with fat-saturated T1 weighting so that an increased contrast of the hematoma can be obtained in the first image data.

[0030] It is conceivable that the coherent volume element of the first image data with high contrast or a contrast higher than a predetermined threshold is identified as a fluid accumulation and is registered with the navigation plan. It is also conceivable that the fluid accumulation is the target area of ​​the catheter in the tissue of the medical target object. In this case, the path of the catheter through the blood vessel or vascular tree and / or the positioning instructions of the navigation plan can be adjusted so that the catheter can be guided to the fluid accumulation of the medical target object. In another example, the detected fluid accumulation represents an aneurysm, which is associated with an increased risk of complications. Under the risk of an aneurysm about to rupture, the path of the catheter through the blood vessel or vascular tree and / or the positioning instructions of the navigation plan can be adjusted so that the catheter is avoided from directly contacting the aneurysm. For example, it is conceivable that when navigating to the target area, the catheter is guided along the alternative section of the vascular tree to avoid contact with the fluid accumulation part. Here, for example, the risk of vascular rupture can be determined by means of a biomechanical model or a model-based method.

[0031] By adjusting the parameter set of the first imaging mode and / or the second imaging mode to detect fluid accumulation in the vascular tree, information about the pathological condition of the medical target object that is important for the navigation of the catheter can be output in an advantageous manner together with the first image data and / or the navigation plan. Based on the spatial position of the fluid accumulation part, the path of the catheter in the vascular tree of the tissue can be planned more effectively when creating the navigation plan, thereby reducing the time for navigating the catheter into the target area in an advantageous manner. In addition, fluid accumulation parts with an increased risk of complications when contacting the catheter can be taken into account when creating the navigation plan, thereby reducing the risk of vascular rupture in an advantageous manner.

[0032] In a possible embodiment of the method according to the invention, second image data of the tissue are detected by means of a first imaging mode or a second imaging mode, wherein the parameter set of the first imaging mode or the second imaging mode is selected when detecting the second image data so that the speed of advance of the liquid in the blood vessels of the tissue is determined, wherein the navigation plan is created based on the information about the speed of advance of the liquid in the blood vessels of the tissue. It is conceivable that the second image data includes spatially resolved velocity values ​​and / or velocity vectors of the blood in the tissue of the medical target object. The second image data and the first image data and / or the first elasticity data can be based on a common coordinate system so that when creating the navigation plan, the velocity values ​​and / or velocity vectors can be associated with the corresponding contrast and / or elasticity values ​​of the volume element according to the coordinates. As described above, the second image data, the first image data and / or the second elasticity data can also be transformed or deformed in order to achieve correlation. Preferably, the second image data is detected in time before the creation of the navigation plan. Here, the second image data can be recorded while detecting the first image data or the first elasticity data.

[0033] It is conceivable that the velocity values ​​and / or velocity vectors of the second image data are used to detect bleeding, vasoconstriction and / or vasodilation. Changes in the cross section of the blood vessel can locally change the flow velocity in the blood vessel and thus characterize deposits or aneurysms. Preferably, information about the local changes in the flow velocity is registered as a potential deposit or potential aneurysm in the navigation plan. In order to detect local changes in the flow velocity, for example, an average value of the flow velocity can be determined at discrete intervals along the blood vessel. Preferably, information about the local changes in the flow velocity is taken into account when planning the path of the catheter in the blood vessel of the medical examination object.

[0034] By determining the flow rate of the blood in the vascular tree, information about local contraction and / or relaxation of the cross section of the blood vessels can be obtained, but also information about bleeding. The information about local contraction and / or relaxation of the cross section of the blood vessels can be combined in an advantageous manner with information about fluid accumulation and / or deposits of the first image data in order to improve the assessment of the risk of complications for the medical target object.

[0035] In another embodiment of the method according to the invention, the limit value distribution is determined by means of a biomechanical model of the tissue and / or a model-based method. The biomechanical model of the tissue can include an artificial and / or virtual replica of the tissue by means of mechanical, anatomical and / or physiological laws. In particular, the biomechanical model can be suitable for determining and / or predicting the characteristics and / or behavior of the tissue, such as elasticity values ​​or deformation, under dynamic conditions, such as in the movement of the medical target object or in the force effect caused by the catheter. It is conceivable that the biomechanical model can read the spatially resolved tissue information of the first image data, the second image data and / or the first elastic data in order to determine the characteristics and / or behavior of the tissue. The biomechanical model is particularly designed to determine the deformation of the blood vessel caused by the catheter along the blood vessel. For this purpose, the biomechanical model can include information about the material characteristic values ​​and / or structural configuration of the catheter, which is used to determine the deformation of the catheter and / or the force effect of the catheter on the blood vessel wall. It is conceivable that the maximum force effect and / or the allowed deflection of the volume element of the tissue is determined by means of the biomechanical model and stored or output as a limit value distribution. The biomechanical model preferably comprises a subdivision of the tissue into a finite number of subvolumes and a system of equations, boundary conditions and numerical methods for determining the properties and / or behavior of the tissue subvolumes.

[0036] In this context, a model-based method can, for example, include a model, an algorithm or a function, by means of which the properties and / or behavior of a tissue can be determined in a simplified manner based on predetermined input variables. The input variables can be any tissue information of the first image data, the second image data, the first elasticity data, but can also be patient information. Preferably, when using a model-based method, the subdivision of the tissue into a plurality of sub-volumes is avoided. For example, it is conceivable that the model-based method has a fitting function (Ausgleichungsfunktion), which determines the maximum force absorption and / or the allowed deflection of the tissue based on the first elasticity data and the age, weight and / or previous diseases (e.g. diabetes) of the medical target object. Statistical data, such as vascular fragility associated with age, weight or previous diseases, can also be used for this purpose.

[0037] It is also conceivable that a model-based method determines the contour of the vessel or the vessel wall due to the force effect caused by the catheter. In this case, coefficients are adjusted, such as polynomial coefficients, spline coefficients, etc., which describe the variation curve of the force effect of the catheter on the vessel wall and / or the deformation of the vessel wall contour caused by the first elasticity value and the force effect in a simplified manner by means of interpolation functions, regression methods or fitting calculations (curve fitting). With the help of this method, any arbitrary, spatially resolved information about the deformation and / or elasticity of the tissue and the vessel wall can be determined.

[0038] By using a biomechanical model or a model-based method, the maximum force absorption of the tissue and / or the limit value of the allowed deflection can be determined in an advantageous manner based on personalized information about the medical target object, such as the first image data, the second image data, the tissue information of the first elastic data and / or the patient information. Therefore, the navigation plan can be adapted to the personalized needs of the medical target object and / or the risk of complications along the planned path can be better predicted.

[0039] In a feasible embodiment of the method according to the present invention, the navigation plan of the catheter is output. It is conceivable that the output of the navigation plan includes transmitting digital and / or analog signals. For example, the digital and / or analog signals can be transmitted to a robot, and the robot is designed to implement the positioning instructions of the navigation plan by means of a guiding unit. However, it is also conceivable that the navigation plan is transmitted to a display unit for visualization. The display unit can be any device at this time, and the device constitutes the tissue information for displaying the navigation plan. In one example, the anatomical structure of the medical target object can be shown on the display unit by means of the contrast of the first image data. The contrast can be superimposed with a color value at this time, and the color value shows the limit value, the elasticity value and the planned path and / or the direction vector of the positioning instruction of the catheter. It is also conceivable that the positioning instruction of the catheter is registered with the real-time image data of the medical target object so that the operator can track the navigation plan with respect to the real-time image data of the catheter in the medical target object. The output of the navigation plan can also represent: the navigation plan is transmitted to the imaging mode, the robot, the server and / or the computing unit via a network, especially an IP-based network, or a bus system.

[0040] By outputting the navigation plan, the navigation plan can advantageously provide the operator with the intervention plan. Furthermore, by registering the navigation plan with the real-time image data, the current position of the catheter can be advantageously determined with respect to the position of the catheter planned based on the navigation plan when the catheter is navigated into the target area. The navigation plan can also be output to a robot, which is designed to limit the movement of the catheter according to the navigation plan. The risk of damage to the blood vessel due to the catheter can thus be advantageously avoided.

[0041] The intervention, ie the actual navigation of the catheter into the target area of ​​the medical target object, can in particular be carried out independently of the method according to the invention for creating a navigation plan with the aid of the above-described embodiments and can therefore be considered separately therefrom.

[0042] The robot for navigating a catheter to a target area of ​​the tissue of a medical target object according to the present invention has a guiding unit, which is configured to change the position and / or orientation of the catheter. The robot can be electrically and / or mechanically connected to an external computing unit and a first imaging mode and / or a second imaging mode. Preferably, for this purpose, the robot has a dedicated interface, which is designed to provide a signal connection to transmit information with an external computing unit, a first imaging mode and / or a second imaging mode. The interface can be configured as any network interface, such as an RJ-45 interface, as any bus interface, such as a CAN bus interface, or as an electrical interface for transmitting analog and / or digital signals. In addition, the robot can be configured as an independent component. In this case, the robot can have an integrated computing unit, but can also have an interface for signal connection with the first imaging mode and / or the second imaging mode.

[0043] The guiding unit is preferably an electric drive, a hydraulic drive, a pneumatic drive or the like, which is designed to transfer a motion to the catheter. This motion can include different degrees of freedom, such as a translational degree of freedom and / or a rotational degree of freedom. It is also conceivable that at least one section of the catheter can be bent by means of the guiding unit. The change in position and / or orientation of the catheter can therefore, for example, include a translational movement along the trajectory of the blood vessel, a rotational movement of the catheter around the axis of the catheter and / or a bending of the catheter.

[0044] The catheter can be controlled according to the navigation plan by means of the guidance unit. This can mean that multidimensional tissue information and / or positioning instructions of the navigation plan are displayed to the operator of the robot by means of the display unit. The operator of the robot can thus control the guidance unit of the robot by means of a remote control device, such as a controller, a joystick, a keyboard, etc., and execute the positioning instructions of the navigation plan.

[0045] It is also conceivable that the robot is designed to interpret the navigation plan and / or the positioning instructions of the navigation plan by means of a computing unit and to move the catheter by means of a guidance unit in response to a triggering by an operator. The triggering by the operator can, for example, comprise a continuous or discontinuous actuation of a button of the remote control, which triggers the movement of the catheter by the robot. Preferably, the computing unit of the robot is designed to process digital and / or analog signals with the tissue information of the navigation plan and to control the guidance unit accordingly.

[0046] Furthermore, it is conceivable to already take into account the design, material composition and / or degrees of freedom of the catheter when creating the navigation plan in order to adapt the navigation plan to the individual requirements of the robot, the catheter and / or the guide unit.

[0047] The robot can also have a means for determining the force absorption of the tissue. Such means can be, for example, a sensor designed to measure the force absorption. Conceivable embodiments of the sensor are, for example, strain gauges, piezoelectric force sensors, electrodynamic force sensors, etc. The sensor can be positioned at the tip of the catheter and connected to a computing unit of the robot via an electrical signal connection along the catheter in order to transmit the measured value of the force absorption at the tip of the catheter to the computing unit. However, it is also conceivable that the sensor is positioned on the guide unit and measures the force absorption of the catheter caused by the drive.

[0048] The calculation unit is preferably designed to determine the difference between the force absorption measured by the sensor and the maximum force absorption of the vessel wall according to the navigation plan. When a limit value is exceeded, for example, an intervention can be interrupted or the orientation and / or position of the catheter can be adjusted. It is also conceivable that when a limit value is exceeded, an operator of the robot is informed by means of a display unit and prompted to take action. In addition, the robot can be designed to limit the movement of the catheter in the direction that causes the limit value to be exceeded.

[0049] By controlling the catheter by means of a robot according to a navigation plan, the accuracy of the navigation of the catheter in the tissue of the medical target object can be increased compared to manual movement of the catheter and undesired exceeding of limit values ​​can be avoided.

[0050] In a feasible embodiment of the robot according to the present invention, the robot is designed to automatically navigate the catheter into the target area according to the navigation plan. Automatically navigating the catheter into the target area can mean that the robot moves the catheter independently through the tissue and / or the vascular tree along the path preset by the navigation plan by means of a guidance unit. Preferably, at the beginning of navigation, the catheter has been introduced into the medical target object. In this embodiment, the robot preferably has a computing unit for processing analog and / or digital information, such as a processor or a microprocessor, and a control unit for adjusting and outputting control signals, such as a controller or a microcontroller. The computing unit of the robot is preferably configured to transmit a series of direction vectors of the positioning instructions and / or the navigation plan to the guidance unit by means of control signals, so that the catheter is navigated into the target area according to the navigation plan. The robot and / or the guidance unit are particularly coordinated with the navigation plan here. This can mean that the positioning instructions of the navigation plan can be implemented by means of the guidance unit of the robot and the available degrees of freedom. Preferably, the computing unit determines the progress of the catheter in the tissue or the vessel, for example by controlling the guide unit in a temporally dependent manner on the speed of the movement of the catheter in the tissue.

[0051] By using a robot which is designed to automatically navigate a catheter into a target area according to a navigation plan, operating errors of the robot when navigating the catheter in the tissue can be avoided in an advantageous manner.

[0052] The system according to the invention comprises a robot according to the invention, a first imaging mode and / or a second imaging mode, and a computing unit, which has a signal connection with the robot, the first imaging mode and / or the second imaging mode and is configured to determine a limit value distribution at least based on first elasticity data and first image data and to create a navigation plan according to the method according to the invention. The robot, the first imaging mode and / or the second imaging mode and the computing unit are preferably configured according to one of the above-mentioned embodiments. The computing unit can be mechanically connected to any system component, such as a first imaging device, a second imaging device, a robot or a display unit. It is also conceivable that the computing unit is configured as an independent component. The computing unit preferably has a dedicated interface, which is designed to provide a signal connection with the robot, the first imaging mode and / or the second imaging mode. The computing unit is particularly designed to determine a limit value distribution at least based on first elasticity data and first image data. The first elasticity data and the first image data can be transmitted to the computing unit from the first imaging mode and / or the second imaging mode by means of an interface or can be read from a database. The processor of the computing unit is preferably designed to determine a limit value distribution according to the above-described embodiments by means of a biomechanical model or a model-based method and to create a navigation plan for the catheter in the tissue based at least on the first image data and the limit value distribution.

[0053] The system according to the invention is provided in which the system configuration and / or the relative positions of the system components can be defined spatially. Thus, a common coordinate system can be provided for the first imaging mode and the second imaging mode, which advantageously simplifies the correlation and / or registration of the first image data with the first elasticity data. The system configuration also allows the communication infrastructure and / or the information exchange of the system components with the computing unit to be optimized. Thus, the time consumption for transmitting and processing information can be reduced in an advantageous manner.

[0054] In another embodiment of the system according to the present invention, the first imaging mode and / or the second imaging mode are configured to detect the second elasticity data when navigating the catheter into the target area, wherein the computing unit is configured to update the limit value distribution and the navigation plan according to the second elasticity data. Preferably, the second elasticity data is detected by means of an imaging device, and the first elasticity data is also recorded by means of the imaging device. The second elasticity data can be detected according to one of the above embodiments. Preferably, the first imaging device and / or the second imaging device are configured to store the spatially resolved elasticity values ​​of the second elasticity data together with the corresponding coordinates and / or position information in the form of a tuple, vector or matrix, and / or transmit them to the computing unit by means of a signal connection. The computing unit can be configured to supplement, update and / or cover the limit value distribution and the navigation plan according to the second elasticity data and the first image data. Preferably, for this purpose, the computing unit has a synchronization component, which ensures database consistency when the elasticity value is detected and changed at the same time. However, it is also conceivable that the computing unit is configured to determine the second limit value distribution at least according to the second elasticity data. In this case, the navigation plan can be created accordingly by means of weighting the first limit value distribution and the second limit value distribution.

[0055] By detecting the second elasticity data when navigating the catheter into the target area, the influence of the catheter on the elasticity values ​​of the blood vessels in the catheter surroundings can be determined in the measurement. Thus, the limit value distribution determined according to the model can be supplemented with the measurement data and the accuracy of determining the maximum force absorption and / or the allowed deflection of the tissue can be increased in an advantageous manner.

[0056] In another embodiment of the system according to the invention, the robot comprises a sensor which has a signal connection to a computing unit and is designed to detect the force absorption of a volume element of the tissue when the catheter is navigated into the target area. The sensor can be designed according to one of the above-mentioned embodiments. Preferably, the sensor has a direct or indirect signal connection to the computing unit in order to transmit the measured value of the force absorption. A direct signal connection can be an electrical connection for transmitting analog or digital information. An indirect signal connection can mean that the information transmitted by the sensor is processed and / or adjusted by another processor before being transmitted to the computing unit, i.e. converted into an arbitrary data format, wherein the other processor is located, for example, on the sensor or the robot.

[0057] The computing unit is designed to output information and / or limit the movement of the catheter when a limit value for the force absorption of a volume element of the tissue is exceeded. The information can be, for example, a positioning instruction of a navigation plan. The positioning instruction can include limiting catheter movements that would cause an impermissible deflection of the tissue and / or exceed a maximum force absorption. The positioning instruction can also include a signal for terminating the catheter movement.

[0058] It is also conceivable that the information includes an indication or a warning. The display unit can be designed to output an indication or a warning, for example, in order to inform an operator that a limit value has been exceeded or is about to be exceeded due to a movement of the catheter. It is also conceivable that the properties of the indication are adjusted depending on the measured force absorption. The indication can include any object, the color, shape, positioning and / or geometry of which can be changed depending on the measured force absorption of the tissue.

[0059] By measuring the force absorption by means of a sensor, the catheter movement can be automatically limited in an advantageous manner when the maximum force absorption of the tissue is exceeded. Thus, damage to the tissue, for example due to unintentional contact with the vessel wall, can be reduced in an advantageous manner.

[0060] In another embodiment of the system according to the present invention, the first imaging mode and / or the second imaging mode are configured to detect the third image data when the catheter is navigated into the target area. Similar to the first image data, the third image data can have a spatially resolved contrast of the anatomical structure in the medical target object. The third image data preferably also contains a spatially resolved contrast of a catheter or a part of a catheter. The imaging area of ​​the first imaging mode and / or the second imaging mode can be directed to or adapted to the catheter and the tissue surrounding the catheter in this case.

[0061] In this embodiment, the calculation unit is designed to determine the force absorption and / or deflection of the volume element of the tissue based on the third image data, and output information when the maximum force absorption and / or the limit value of the allowed deflection of the volume element of the tissue is exceeded. It is conceivable that the calculation unit has an image processing unit, which is configured to quantify the difference between the spatial orientation of the volume element of the tissue of the third image data and the spatial orientation of the volume element of the tissue of the first image data. This difference can represent the deflection that occurs due to the navigation of the catheter in the tissue. The first image data can be used as a reference measurement here, for example. Preferably, the calculation unit is also configured to quantify the limit value of the deflection exceeded by the volume element based on the difference in the spatial orientation of the volume element of the tissue, and output it via a display unit.

[0062] The computing unit can also be designed to determine the force absorption of the tissue based on the spatially resolved contrast of the catheter. To this end, information about the catheter, such as the structural structure, material composition or model of the catheter, is stored in a database or memory and read by the computing unit. The image processing unit of the computing unit can be configured to determine the deformation of the catheter, such as bending, twisting, spiraling, etc., based on the third image data and determine the force absorption of the tissue surrounding the catheter based on the information about the catheter. As mentioned above, the computing unit can also be designed to determine the limit value of the force absorption exceeding the volume element based on the deformation of the catheter. Information about exceeding the limit value can be output on the display unit and / or include positioning instructions transmitted to the robot and / or the guidance unit. It is conceivable that the computing unit updates the navigation plan, especially the positioning instructions of the navigation plan, based on the third image data. In addition, the computing unit can be configured to transmit the third image data together with the navigation plan to the display unit to inform the operator of the robot of the current position of the catheter and / or the progress of the catheter in the tissue. It is particularly conceivable that the third image data is recorded by means of an X-ray device or a fluoroscopy device.

[0063] By detecting the third image data, the force absorption and / or deflection of the tissue caused by the movement of the catheter can be advantageously monitored and output in real time, so that the risk of complications, for example due to undesired deflection of the vessel wall, can be advantageously avoided.

[0064] In a possible embodiment of the system according to the invention, the computing unit is designed to output information about the force absorption and / or deflection of the volume element of the tissue when the catheter is navigated into the target area. Here, the force absorption and / or deflection of the volume element of the tissue can be measured and / or determined according to one of the above embodiments, and updated continuously or at discrete time intervals when the catheter is navigated into the target area. The information about the force absorption and / or deflection of the volume element of the tissue can be, for example, the force absorption and / or deflection of the volume element determined according to the sensor and / or the third image data. However, it is also conceivable that the information is determined according to the limit value of the force absorption and / or deflection and the measured or determined force absorption and / or deflection. In one example, the information can be the difference formed by the maximum force absorption and the measured force absorption. In another example, the information can be a color value, a geometric object, a text output or a combination thereof, which encodes, for example, the measured force absorption, the maximum force absorption or the difference between the measured force absorption and the maximum force absorption. For example, a volume element or multiple volume elements of the tissue can be marked by means of red coloring or an exclamation mark in order to indicate to the operator of the robot that the limit value of the force absorption in the volume element or multiple volume elements is locally exceeded. In another example, information about exceeding the allowed deflection of a volume element or multiple volume elements of the tissue can be output in the form of force feedback, for example vibration of a remote control device of the robot. In this case, the robot and / or the remote control device is configured to output the force feedback. The information can also be a control command to terminate the movement of the catheter. It is conceivable that the computing unit has a controller or a microcontroller to output the control command, and the controller or microcontroller transmits the control command to the robot and / or the guidance unit of the robot by means of an analog or digital signal.

[0065] Furthermore, the computing unit can be designed to determine information about the force absorption and / or deflection of the volume element of the tissue and transmit it to a display unit. Preferably, the information about the force absorption and / or deflection of the volume element of the tissue is assigned position information and / or coordinates, which allow the information to be associated with the contrast space of the first image data and / or the third image data. The computing unit can be designed in particular to register the information about the force absorption and / or deflection of the volume element of the tissue with the first image data and / or the third image data and transmit it to a display unit.

[0066] By outputting information about the force absorption and / or deflection of a volume element of the tissue and registering this information with the third image data, the operator of the robot can be informed of the current load state of the tissue in an advantageous manner. In addition, by outputting force feedback to the operator or outputting control commands to the guidance unit, perforation of the tissue or rupture of blood vessels can be avoided in an advantageous manner when limit values ​​are exceeded.

[0067] The computer program product according to the invention can be loaded into the memory of the computing unit of the system and has a program code mechanism so that when the computer program product is executed in the computing unit of the system, the method according to the invention is executed. The computer program product according to the invention makes it possible to quickly, identically reproducibly and robustly execute the method according to the invention. The computer program product is configured so that it can execute the method steps according to the invention by means of the computing unit. The computing unit must have the prerequisites, such as a corresponding working memory, a corresponding graphics card or a corresponding logic unit, so that the corresponding method steps can be effectively executed. The computer program product is stored, for example, on a computer-readable medium or on a network, a server or a cloud, from which the computer program product can be loaded into the processor of a local computing unit, which can be configured as an independent system component or as part of the first imaging mode, the second imaging mode, the display unit or the robot. In addition, the control information of the computer program product can be stored on an electronically readable data carrier. The control information of the electronically readable data carrier can be designed so that when the data carrier is used, the control information executes the method according to the invention in the computing unit of the combined imaging device. Examples of electronically readable data carriers, on which electronically readable control information, in particular software, is stored, are DVDs, magnetic tapes or USB sticks. If the control information is read from the data carrier and stored in a control device and / or a computing unit of the system according to the invention, all embodiments according to the invention of the above-described method can be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Further advantages and details of the invention can be seen from the exemplary embodiments described below and from the accompanying drawings. Here, it is shown:

[0069] Figure 1 An embodiment of the system according to the present invention is shown;

[0070] Figure 2 An embodiment of the system according to the present invention is shown;

[0071] Figure 3 A schematic diagram showing a feasible navigation plan in a blood vessel of a medical target object;

[0072] Figure 4 A schematic diagram showing a feasible navigation plan in a blood vessel of a medical target object;

[0073] Figure 5 A schematic diagram showing a feasible navigation plan in a blood vessel of a medical target object;

[0074] Figure 6 A possible flow chart of the method according to the invention is shown. DETAILED DESCRIPTION

[0075] Figure 1 An embodiment of a system 1 according to the invention is shown, which in the present case has an X-ray device 2, which has a C-arm 6, on which an X-ray emitter 7 and an X-ray detector 8 are arranged opposite each other. In the embodiment shown, the X-ray device 2 is in a second imaging mode, which forms first image data and / or third image data for detecting tissue. In the example shown, the tissue is a blood vessel 32 of a medical target object, which in this case is a patient 15. The X-ray device 2 is oriented so that a target region 9 of the patient 15 positioned on a patient table 17 can be imaged. The target region 9 is a tissue section positioned between a starting point 30 and a target region 31 of a catheter 34. In the example shown, the target region 9 corresponds to the current imaging region of the X-ray device 2. With the help of the C-arm 6, the X-ray device 2 formed by the X-ray emitter 7 and the X-ray detector 8 can be moved to different imaging positions relative to the patient 15 supported on the patient table 17, so that the imaging region of the X-ray device 2 can be moved along the blood vessel 32 as the catheter 34 advances from the starting point 30 to the target region 31.

[0076] The X-ray device 2 also has a control unit 4, which is designed to control the X-ray device 2. The tasks of the control unit 4 can include, in particular, setting different imaging parameters, coordinating different steps of image acquisition and image processing, and transmitting the first image data or the third image data to a computing unit 40 of the system 1. The system 1 also includes a display unit 41 and an operating unit 42 to enable interaction with an operator. In the present embodiment, the computing unit 40 is integrated into a computer or PC and is connected to the display unit 41 and the operating unit 42. The computing unit 40, the display unit 41 and the operating unit 42 form a user interface 23, via which, for example, the method according to the invention can be started, ended and / or parameterized.

[0077] In the example shown, the operator is a therapist 29 who is at a distance 3 from the X-ray emitter 7 and operates the robot 50 via a remote control 52. The robot 50 has a guide unit 51 which moves the catheter 34 in the blood vessel 32 along a planned path 80, for example according to control commands of the remote control 52.

[0078] In the embodiment of the system 1 according to the invention shown, the first imaging mode is an ultrasound device 60. The ultrasound device 60 has an ultrasound probe 61, which is configured to record the first elasticity data and / or the second elasticity data of the tissue. To this end, the ultrasound probe is positioned at the target area 9 of the patient 15, in which the tip of the catheter 34 is located. The ultrasound device 60 can be configured, for example, as an ultrasound device for 3D elastic imaging or an ultrasound device for 2D elastic imaging. Preferably, the ultrasound device 60 is configured to support common ultrasound examination methods, such as a one-dimensional Doppler method, a two-dimensional Doppler method or a dual method.

[0079] In the example shown, the ultrasound device 60 and the X-ray device 2 are connected to the computing unit 40 via signal connections 43a and 43b. The signal connections 43a and 43b enable a bidirectional exchange of analog and / or digital information. Preferably, at least digitized tissue information, such as the first image data of the X-ray device 2 and the tissue information of the first elasticity data of the ultrasound device 60, is transmitted to the computing unit 40. However, it is also conceivable that the computing unit 40 determines the detection of the first image data, the second image data, the third image data, the first elasticity data and / or the second elasticity data and transmits the control command for executing the corresponding measuring method to the control unit 4 of the X-ray device 2 and / or the ultrasound device 60. The control unit 4 of the X-ray device 2 and the ultrasound device 60 are preferably designed to determine the corresponding parameter set, such as a plurality of imaging parameters, based on such control command, and implement the parameter set in the measuring method. In addition, the computing unit 40 is connected to the robot 50 via the signal connection 43d. The signal connection 43d can also be designed to enable a bidirectional exchange of analog and / or digital information between the computing unit 40 and the robot 50. Examples of such information are control commands, positioning instructions, tissue information or measurements of the force absorption by sensors of the catheter (not shown).

[0080] exist Figure 2 A further embodiment of the system 1 according to the invention is shown in . In this example, the first imaging mode corresponds to the second imaging mode, which is a magnetic resonance device 10 with an active drive device 71 and a passive drive 72 for performing elastography measurements.

[0081] The magnetic resonance device 10 includes a magnet unit 11, which has, for example, a permanent magnet, an electromagnet or a superconducting main magnet 12 to generate a strong and, in particular, uniform main magnetic field 13. In addition, the magnetic resonance device 10 includes a patient accommodation area 14 for accommodating a patient 15. In the present embodiment, the patient accommodation area 14 is cylindrically configured and is surrounded by the magnet unit 11 in the circumferential direction. However, in principle, configurations of the patient accommodation area 14 different from this example are also conceivable.

[0082] The patient can be positioned in the patient accommodation area 14 by means of a patient support device 16 of the magnetic resonance device 10. For this purpose, the patient support device 16 has a patient table 17 designed to be movable in the patient accommodation area 14. The magnet unit 11 also has a gradient coil 18 for generating a magnetic field gradient, which is used for spatial encoding during imaging. The gradient coil 18 is controlled by means of a gradient control unit 19 of the magnetic resonance device 10. In addition, the magnet unit 11 can include a high-frequency antenna, which in the present embodiment is designed as a body coil 20 fixedly integrated into the magnetic resonance device 10. The body coil 20 is designed to excite the nuclei located in the main magnetic field 13 generated by the main magnet 12. The body coil 20 is controlled by a high-frequency unit 21 of the magnetic resonance device 10 and radiates high-frequency signals into an examination space substantially formed by the patient accommodation area 14 of the magnetic resonance device 10. The body coil 20 is also designed to receive magnetic resonance signals.

[0083] In order to control the main magnet 12, the gradient control unit 19 and the high-frequency unit 21, the magnetic resonance device 10 has a control unit 4. The control unit 4 is configured to control the execution sequence, such as a gradient echo sequence or a fast spin echo sequence of imaging. In the example shown, the control unit 4 also includes a calculation unit 40, which is also configured to evaluate the digitized magnetic resonance signals detected during the magnetic resonance examination. The calculation unit 40 and the control unit 4 are configured, for example, to transmit digital and / or analog information to the active drive device 71 and the robot 50 via a signal connection 43e. Such information can include control commands executed by the active drive device 71 and the robot 50. The calculation unit 40 and the control unit 4 can also be configured to receive signals and / or information from the active drive device 71 via the signal connection 43e.

[0084] Furthermore, the magnetic resonance device 10 comprises a user interface 23, which has a signal connection to the control unit 4. The display unit 41 of the user interface 23 is preferably designed to display the parameter set, the first image data, the second image data, the third image data, the first elasticity data, the second elasticity data, the limit value distribution and / or the navigation plan to the therapist 29 on a monitor of the user interface 23. Furthermore, the user interface 23 comprises an operating unit 42, by means of which the parameter set of the magnetic resonance device 10 can be adjusted by the therapist 29. The user interface 23 can also provide the possibility of starting, ending and / or parameterizing the method according to the invention.

[0085] The magnetic resonance device 10 further comprises a local coil 26 which is positioned on the patient 15 and transmits magnetic resonance signals of a body region of the patient 15 to the magnetic resonance device 10. The local coil 26 has an electrical connection line 27 which provides a signal connection to a corresponding receiving channel of the high-frequency unit 21 and the control unit 22. The receiving channel filters and digitizes the signals received by the local coil 26 and transmits the data to a computing unit 40 which derives an image or a spectrum from the data and provides it to a therapist 29 via a display unit 41. For example, a passive drive 72 which radiates sound waves into the tissue of the patient 15 can be mechanically connected to the local coil 26. In the example shown, the passive drive 72 is controlled by means of an active drive device 71 via a signal connection 43c.

[0086] In the example shown, the computing unit 40 and the control unit 4 are connected to the robot 50 via a signal connection 43d. It is conceivable that when the maximum force absorption and / or the permitted deflection of the tissue is exceeded, the computing unit 40 outputs a control command, which is transmitted to the robot 50 by means of the control unit 4 and the signal connection 43d. Such a control command can, for example, include limiting the movement of the catheter 34 in a spatial direction or terminating the movement of the catheter 34. In one embodiment, the catheter 34 has a sensor for determining the force effect on the tissue of the patient 15. The measured force effect can be transmitted to the robot 50, for example, via the connection line of the catheter 53. It is conceivable that the robot 50 automatically limits the movement of the catheter 34 as a function of the measured force effect. It is also conceivable that the measured force effect is transmitted to the computing unit 40 by means of the signal connection 43d. In one embodiment, the computing unit 40 is designed to transmit the measured force effect to the display unit 41 for visualization. The computer unit 40 can also be designed to output control commands to a robot 50 which limits the movement of the catheter as a function of the measured force effects.

[0087] exist Figure 1 and Figure 2 The computing unit 40 shown in the embodiment of is also designed to transmit information, such as first image data, second image data, third image data, first elasticity data, second elasticity data as well as tissue information of the limit value distribution and / or the navigation plan to a display unit 41. The information can be present in a suitable data format, such as a DICOM format. It is conceivable that the display of the information can be adjusted and / or changed by the therapist 29 with the aid of the operating unit 42, for example in order to be able to change the color value of the elasticity value registered in the first image data or to select a two-dimensional image segment from the three-dimensional first image data. In addition, in Figure 1 and 2The system components in the embodiment are electrically and mechanically connected to one another by means of signal connections 43a-e. However, it is also conceivable that the system components have a network interface that enables wireless communication between the system components. It is also conceivable that the information exchange between the system components is carried out partially via analog signals (for example in the case of control commands) and partially wirelessly (for example in the case of first image data).

[0088] Figure 3 A schematic diagram of a possible navigation plan 82 in the tissue of a patient 15 is shown. The navigation plan 82 has a two-dimensional segment of first image data with a spatially resolved contrast of the anatomical structure of the patient 15. The segment of the first image data shows a blood vessel 32, through which a catheter 34 is to be navigated. The navigation plan 82 also includes the coordinates of a planned path 80 through the blood vessel 32. The planned path 80 is aligned with the segment of the first image data so that the planned path 80 can be shown on the display unit 41 as a line with respect to the anatomical structure of the patient 15. In the segment of the first image data, the blood vessel 32 is embedded in the surrounding tissue 35, which can affect the properties of the vessel wall of the blood vessel 32, in particular the elastic properties.

[0089] In the example shown, the blood vessel 32 has a deposit, which is positioned on the blood vessel wall along the planned path 80 of the catheter 34. It is conceivable that the deposit 36 ​​is the target area 31 of the catheter 34. In this case, the catheter 34 can be configured, for example, as a balloon catheter, which is expanded behind the deposit 36 ​​in the flow direction of the blood, so as to remove the deposit 36 ​​from the blood vessel 32 by means of the catheter 34. The catheter 34 can also be configured to remove the deposit by applying a mechanical force. It is also conceivable that the deposit 36 ​​is positioned on the path leading to the target area 31, and the mechanical interaction of the catheter 34 with the deposit 36 ​​should be reduced or avoided. In this case, the planned path 80 of the navigation plan 82 can be designed so that the catheter 34 passes or bypasses the deposit 36 ​​with minimal interaction, for example by navigating into the branch 38 of the blood vessel 32.

[0090] Figure 4 Another schematic diagram shows a possible navigation plan 82 in the tissue of a patient 15 . In this case, the target area 31 is a vascular aneurysm that is to be treated by interventional forces. The treatment can include, for example, embolization with the aid of coils and / or stenting with the aid of a catheter 34 .

[0091] Figure 5A navigation plan 82 is shown, which is registered with a two-dimensional segment of third image data with spatially resolved contrast of the anatomical structure of the patient 15. The third image data includes a real-time image of the tissue of the patient 15 and the catheter 34 in the blood vessel 32. The catheter 34 has contact points with the vessel wall of the blood vessel 32 at multiple locations, at which forces are transmitted from the catheter 34 to the vessel wall. In this case, the vessel wall of an aneurysm may be particularly important, which vessel wall may be subjected to increased forces during embolization with coils.

[0092] In order to evaluate the load on the vessel wall, the two-dimensional segment of the third image data is also registered in the navigation plan 82 with information about the force absorption and / or deflection of the vessel wall, which is visualized on the display unit 41 in the form of objects 81a to 81c. In the example shown, objects 81a-c are shown at each contact point of the catheter 34 with the vessel wall of the vessel 32, which objects display the level of the force effect and the difference from the maximum force absorption of the limit value distribution. The level of the force absorption is encoded via the size of the objects 81a-c, and the difference from the maximum force absorption is encoded via the color value of the objects 81a-c. In the example shown, the color of the objects 81b and 81c can be green, for example, so that the small force effect of the catheter 34 on the vessel wall can be signaled, which locally does not exceed the maximum force absorption. If the filling of the aneurysm with a coil applies a locally increased pressure to the vessel wall of the aneurysm, the color of the object 81a can be orange. Upon detection of an exceeding of the maximum force absorption of a volume element, the computing unit 40 can output a signal which causes a force feedback on the remote control 52 of the therapist 29 and / or an immediate termination of the movement of the catheter 34 .

[0093] Figure 6 A possible flow chart of a method according to the invention for creating a navigation plan 82 for a catheter 34 in tissue based on a limit value distribution is shown.

[0094] In an optional step S1 of the method, first image data of the tissue are detected by means of a first imaging mode and / or a second imaging mode. The detection of the first image data can be performed, for example, by means of a magnetic resonance device 10, an X-ray device 2, an ultrasound device 60, etc. In the following embodiments of the method, the tissue is a blood vessel 32 with surrounding tissue 35. Preferably, a medical target object, for example a patient 15, is positioned on a patient table 17 of a first imaging device and / or a second imaging device in a predetermined position, so that the position of the patient 15 when recording the first image data is consistent with the position of the patient 15 when recording the first elasticity data, the second elasticity data, the second image data and / or the third image data. When detecting the first image data, preferably three-dimensional tissue information of anatomical structures in the tissue 35 of the patient 15 is recorded. The three-dimensional tissue information is, for example, a contrast or grayscale value, which is associated with the position information or coordinates of the volume element of the tissue via a tuple, a vector or a matrix. Preferably, the parameter set of the first imaging mode and / or the second imaging mode is set so that the anatomical and / or pathological structures important for the navigation catheter 34 are recorded with high contrast. Such anatomical or pathological structures can include, among others, deposits 36 on the vessel wall, vascular aneurysms and vascular ruptures.

[0095] In a further step (S2) of the method, a first elasticity value of the tissue is detected by means of a first imaging mode, wherein the first elasticity data include spatially resolved elasticity values ​​of volume elements of the tissue. The first imaging mode can be, for example, a magnetic resonance device 10 or an ultrasound device 60, which is designed to measure elasticity values. Preferably, when detecting the first elasticity data, the patient 15 is located on a patient table 17 of the first imaging mode in a predetermined position. The predetermined position of the patient 15 can here coincide with the predetermined position of the patient 15 when recording the first image data.

[0096] When acquiring the first image data, spatially resolved elasticity values ​​of volume elements of the tissue are recorded by means of a first imaging mode. The elasticity data are preferably three-dimensional tissue information, wherein the elasticity values ​​are linked to position information or coordinates of the volume elements of the tissue via tuples, vectors or matrices.

[0097] In another step (S3), the first image data is read and associated with the first elasticity data, wherein the elasticity value of the volume element of the tissue is assigned to the volume element of the tissue of the first image data. The reading of the first image data is preferably performed via a computing unit 40, which receives the first image data from the first imaging mode and / or the second imaging mode or reads the first image data from a database, such as a physical memory or a cloud memory. The computing unit 40 then associates the first elasticity value with the first image data. Preferably, the first image data and the first elasticity data have a common coordinate system here, so that the elasticity value of the volume element of the tissue can be associated with the grayscale value of the volume element of the tissue according to the coordinates. However, it is also conceivable that the association of the first image data and the first elasticity data is performed by means of a transformation, an iterative method and / or another mathematical operation. The elasticity value is preferably registered with the first image data here. This can mean that the elasticity value is superimposed on the first image data, for example, in the form of a color mark or a pattern. Preferably, the target area 31 and / or other anatomical structures important for creating the navigation plan 82, such as deposits 36 or aneurysms, have been compared in the first image data.

[0098] Furthermore, patient information is preferably read out when reading out the first image data, which can include, in particular, the treatment history, medical history, age, sex, and weight of the patient 15 .

[0099] In an optional step S4 of the method, second image data of the tissue are acquired by means of the first imaging mode or the second imaging mode, wherein the parameter set of the first imaging mode or the second imaging mode is selected during the acquisition of the second image data in such a way that the velocity of advance and / or the pressure gradient of the fluid in the vessels 32 of the tissue can be determined, wherein a navigation plan 82 is created based on the information about the velocity of advance and / or the pressure gradient of the fluid in the vessels 32 of the tissue. The first imaging mode or the second imaging mode can be, for example, a magnetic resonance device 10, an ultrasound device 60, a computed tomography device, etc., which is designed to measure flow velocity. Preferably, during the acquisition of the second image data, the patient 15 is located on the patient table 17 of the first imaging mode or the second imaging mode in a predetermined position. The predetermined position of the patient 15 can here coincide with the predetermined position of the patient 15 during the acquisition of the first image data and / or the first elasticity data.

[0100] The parameter set can include different imaging parameters of the first imaging mode or the second imaging mode, but also the dose of the contrast agent. When detecting the second image data, the spatially resolved velocity values ​​and / or velocity vectors of the blood in the blood vessels 32 of the tissue are measured. It is conceivable that the computing unit 40 first associates the second image data with the first image data before creating the navigation plan 82. Preferably, the first image data and the second image data have a common coordinate system here, so that the velocity values ​​of the volume elements of the blood vessels 32 can be associated with the grayscale values ​​of the volume elements of the blood vessels 32. However, it is also conceivable that the association of the first image data and the second image data is carried out by means of a transformation, an iterative method and / or another mathematical operation. The velocity values ​​are preferably aligned with the first image data here. This can mean that the velocity values ​​are superimposed on the first image data, for example in the form of a color mark or a pattern.

[0101] In another step S5 of the method, a limit value distribution is determined at least according to the first elastic data and associated with the first image data, wherein the limit values ​​of the volume element of the tissue are assigned to the volume element of the tissue of the first image data. For example, the limit value distribution can be determined by means of a biomechanical model and / or a model-based method. The biomechanical model can be based on the numerical solution of a (differential) equation system, by means of which the characteristics of the tissue can be determined at discrete support locations. The support location can correspond to a limited number of equally spaced sub-volumes of the tissue. Alternatively or in addition to the biomechanical model, a model-based method can be used to determine the limit value distribution. It is conceivable that the model-based method has the following function, which adjusts the maximum force absorption and / or the allowed deflection of the tissue according to empirical data by means of a fitting calculation. The empirical data can be associated with the weight, age, sex or previous illness of the patient 15 and the type of volume element of the tissue, slice thickness (first image data) or elasticity value, etc., and the correlation of these variables is provided in the form of a function. In addition, other methods are obviously conceivable as described above.

[0102] The limit value distribution is then associated with the first image data, wherein the limit values ​​of the volume elements of the tissue are assigned to the volume elements of the tissue of the first image data. Preferably, the limit value distribution and the first image data have a common coordinate system, so that the limit values ​​of the volume elements of the tissue can be associated with the contrast or grayscale values ​​of the volume elements of the tissue. However, it is also conceivable that the association of the limit value distribution and the first image data is carried out by means of a transformation, an iterative method and / or another mathematical operation. The limit values ​​are preferably aligned with the first image data. This can mean that the limit values ​​are superimposed on the first image data, for example, in the form of a text window, a colored marking of a pattern, etc.

[0103] In another step S6 of the method, a navigation plan 82 for the catheter 34 in the blood vessel 32 is created at least based on the first image data and the limit value distribution. When creating the navigation plan 82, for example, multiple tuples, multiple vectors or matrices are applied, which associate the coordinates and / or position information of the volume element of the tissue with the gray value or contrast of the first image data and the limit value. It is also conceivable that the spatially resolved velocity and / or pressure gradient of the second image data can also be associated with the coordinates and / or position information of the volume element of the tissue. In addition, the gray value or contrast of the anatomical structure can also be derived from the first image data, wherein the deposit 36 ​​or the liquid accumulation has a particularly high contrast.

[0104] The navigation plan 82 also has a planned path 80 on which the catheter 34 is guided through the blood vessel 32. To determine the planned path 80, an optimization method or an iteration method is used, for example, which reduces or minimizes the load on the vessel wall of the blood vessel 32 caused by the catheter 34 along the planned path 80. In one embodiment, the planned path 80 is stored, for example, as a sequence of direction vectors. In an alternative embodiment, the planned path 80 is stored as a series of coordinates and / or a series of positioning instructions. The sequence of coordinates and / or the sequence of positioning instructions can then be output together with the navigation plan 82 or separately therefrom.

[0105] In an optional step S7, the navigation plan 82 of the catheter 34 is output. The output can include, for example, the visualization of a two-dimensional or three-dimensional image segment on the display unit 41, the two-dimensional or three-dimensional image segment having the contrast of the first image data, the first elasticity data and the elasticity values ​​of the planned path 80. In this case, the plurality of tuples, vectors or matrices of the navigation plan 80 described in step S6 can be converted by the calculation unit 40 into a multidimensional virtual imaging of the blood vessel 32 and / or the surrounding tissue 35, from which arbitrarily oriented, three-dimensional or two-dimensional images and / or image segments can be created. The elasticity values, velocity values ​​and / or limit values ​​are here, for example, registered with the image and / or can be selectively inserted or hidden as layers or slices by the operator.

[0106] In one embodiment, the elasticity values, speed values, limit values ​​and the planned path of catheter 34 through blood vessel 32 are superimposed or registered with the third image data of the tissue so that the therapist 29 can track the progress of the intervention based on the real-time image on the display unit 41.

[0107] In another embodiment, when outputting the navigation plan 82, control commands are also output, according to which the catheter 34 is moved in the blood vessel 32. In this case, a sequence of coordinates and / or a sequence of positioning instructions of the navigation plan 82 can be transmitted as control commands to the robot 50 and / or the guidance unit 51. The control commands can then be converted into movements of the catheter 34 by means of a drive of the robot 50 or the guidance unit 51.

[0108] The method described here can also be present in the form of a computer program which, when executed on the computing unit 40, implements the method on the computing unit 40. There can also be an electronically readable data carrier (not shown) with electronically readable control information stored thereon, which includes at least one of the described computer programs and is designed such that, when the data carrier is used in the computing unit 40, it executes the described method.

[0109] Although the present invention has been illustrated and described in detail by way of preferred embodiments, the present invention is not limited to the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of the present invention.

Claims

1. A method for creating a navigation plan (82) for a catheter (34) in tissue based on a limit value distribution, the limit value distribution comprising spatially resolved limit values ​​of a maximum force absorption and / or an admissible deflection of a volume element of the tissue, the method comprising the following steps: - detecting first elasticity data of the tissue by means of a first imaging modality, wherein the first elasticity data comprise spatially resolved elasticity values ​​of volume elements of the tissue, - reading first image data and associating the first elasticity data with the first image data, wherein elasticity values ​​of volume elements of the tissue are assigned to volume elements of the tissue of the first image data, - determining the limit value distribution at least as a function of the first elasticity data and associating the limit value distribution with the first image data, wherein limit values ​​of volume elements of the tissue are assigned to volume elements of the tissue of the first image data, - creating a navigation plan (82) for the catheter (34) in the tissue based at least on the first image data and the limit value distribution.

2. The method according to claim 1, further comprising the following steps: - first image data of the tissue are acquired by means of the first imaging modality and / or the second imaging modality.

3. The method according to claim 2, wherein when detecting the first image data, a parameter set of the first imaging mode and / or the second imaging mode is selected so that deposits (36) in blood vessels (32) of the tissue are detected, wherein the navigation plan (82) is created based on information about the deposits (36) in the blood vessels (32).

4. The method according to claim 2, wherein when detecting the first image data, a parameter set of the first imaging mode and / or the second imaging mode is selected so as to determine the position of the fluid accumulation part in the tissue, wherein the navigation plan (82) is created based on the information about the fluid accumulation part in the tissue.

5. The method according to any one of claims 2 to 4, further comprising the following steps: - detecting second image data of the tissue by means of the first imaging mode and / or the second imaging mode, wherein a parameter set of the first imaging mode or the second imaging mode is selected when detecting the second image data so that a speed of advancement of the liquid in the blood vessels (32) of the tissue is determined, wherein the navigation plan (82) is created based on the information about the speed of advancement of the liquid in the blood vessels (32) of the tissue. 6 . The method according to claim 1 , wherein the limit value distribution is determined with the aid of a biomechanical model of the tissue and / or a model-based method.

7. The method according to any one of claims 1 to 4, further comprising the following steps: - Outputting a navigation plan (82) for the catheter (34).

8. A robot (50) for navigating a catheter (34) into a target area (31) of tissue of a medical target object, wherein the robot (50) has a guidance unit (51) which is configured to change the position and / or orientation of the catheter (34) and wherein the catheter (34) can be controlled with the aid of the guidance unit (51) depending on a navigation plan according to claim 1, 3, 4 or 5.

9. The robot according to claim 8, wherein the robot (50) is designed to automatically navigate the catheter (34) into a target area (31) according to the navigation plan (82).

10. A system (1) comprising a robot (50) according to claim 8 or 9, a first imaging mode and / or a second imaging mode, and a computing unit (40), the computing unit having a signal connection (43) with the robot (50), the first imaging mode and / or the second imaging mode, and the computing unit being configured to determine a limit value distribution based at least on first elasticity data and first image data, and to create a navigation plan (82) according to a method according to any one of claims 1 to 6.

11. The system (1) according to claim 10, wherein the first imaging mode and / or the second imaging mode is configured to detect second elasticity data when navigating the catheter (34) into the target area (31), and wherein the computing unit (40) is configured to update the limit value distribution and the navigation plan (82) based on the second elasticity data.

12. The system (1) according to claim 10 or 11, wherein the robot (50) comprises a sensor having a signal connection (43) to the computing unit (40) and being designed to detect the force absorption of a volume element of the tissue when navigating the catheter (34) into the target area (31), and wherein the computing unit (40) is designed to output information and / or limit the movement of the catheter (34) when a limit value of the force absorption of the volume element of the tissue is exceeded.

13. The system (1) according to claim 10 or 11, wherein the first imaging mode and / or the second imaging mode is configured to detect third image data when navigating the catheter (34) into the target area (31), and wherein the computing unit (40) is configured to determine the force absorption and / or deflection of a volume element of the tissue based on the third image data and to output information and / or limit the movement of the catheter (34) when a limit value of the force absorption and / or the permitted deflection of the volume element of the tissue is exceeded. 14 . The system ( 1 ) according to claim 11 , wherein the computing unit ( 40 ) is designed to output information about the force absorption and / or deflection of a volume element of the tissue when navigating the catheter ( 34 ) into the target region ( 31 ).

15. A computer program product, which can be directly loaded into the memory of a computing unit (40) of a system (1) according to any one of claims 10 to 14, and which has program code means so that when the computer program product is executed in the computing unit (40) of the system (1), the method according to any one of claims 1 to 7 is executed.

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