Method for generating a manufacturing model for a medical implant

Abstract

Method (1) for generating a manufacturing model (2) for a medical implant (42), wherein: - image data (6, 8) of a body region (14) are provided, - areas (10, 12) are segmented in the image data (6, 8), each corresponding to structures (11, 13) of different tissues, - a shape (18) of the implant (42) is defined based on the areas (10, 12) corresponding to the structures (11, 13), - for at least one structure (11, 13), an interaction (22) with the implant (42) is determined patient-specifically based on the image data (6, 8), wherein the interaction (22) is defined as a load on the at least one structure (11, 13) by the implant (42), - for a number of structures (11, 13), the respective interaction (22) with the implant (42) is checked for exceeding a predefined critical load (26), and - the shape (18) of the implant (42) is defined as a manufacturing model (2),and the manufacturing model (2) is stored on a data carrier (30) and / or output via an interface (32) if the predefined critical load (26) is not exceeded for any tested interaction (22) of the implant (42) with the respective structure (11, 13).

Description

[0001] The invention relates to a method for generating a manufacturing model for a medical implant, wherein image data of a body region are provided, in which areas are segmented which correspond to structures of different tissues, and wherein a shape of the implant is defined on the basis of the areas corresponding to the structures.

[0002] For the production of a medical implant, it is desirable to achieve the highest possible degree of automation for maximum efficiency while still ensuring optimal adaptation to the individual anatomical characteristics of the patient. This inherently precludes complete automation of the manufacturing process. The desire for patient-specific anatomical adaptation applies to implants as diverse as bone implants, intervertebral disc replacements, or cartilage structures for plastic or reconstructive surgery.

[0003] Especially with an implant that is subject to constant stress due to interaction with one or more adjacent tissue structures, for example as a result of movement, a detailed, patient-specific adaptation of the implant to the surrounding tissue can prevent wear and tear caused by this stress. Likewise, this can also reduce undesirable effects of the implant on the tissue structures involved in the interaction, thus helping to prevent inflammation, wear, hardening, and other physical degenerative reactions of the tissue structures resulting from the implant.

[0004] WO 2004 / 110309 describes a method for manufacturing an implant which involves first acquiring three-dimensional tomographic image data of the body region for which the implant is intended and then creating a manufacturing model of the implant based on this image data. The implant is then manufactured using this tomographic image model. WO 2014 / 036551 describes a method for the patient-specific design of an implant which uses three-dimensional tomographic image data, in particular, to determine the two-dimensional contact surfaces of a bone implant with the bone intended for implantation.

[0005] In general, however, the aforementioned methods only acquire image data using one modality, such as computed tomography (CT) or magnetic resonance imaging (MRI), and then directly generate a manufacturing model of the implant using this image data generated by that single modality. This means that the generation of the manufacturing model essentially only considers those anatomical structures of the relevant body region that are particularly well resolved by the modality used—that is, bone structures in the case of CT or soft tissue structures in the case of MRI.

[0006] Information about potential damage to structures that are less well resolved by the modality used is therefore not readily available for generating the manufacturing model. Furthermore, due to the static nature of the image data, possible anatomical changes in the relevant body region (for example, due to movement) that could affect the implant are not taken into account when fitting the implant, nor is any stress on the implant that might result from such anatomical changes.

[0007] The invention is therefore based on the objective of providing a method for generating a manufacturing model for a medical implant, which enables the best possible adaptation of the implant to the patient-specific anatomical conditions of the tissue structures surrounding the implant, taking into account the long-term effects of the interactions between the implant and the surrounding tissue.

[0008] The aforementioned problem is solved according to the invention by a method for generating a manufacturing model for a medical implant, wherein image data of a body region are provided, areas are segmented in the image data, each corresponding to structures of different tissues, a shape of the implant is defined on the basis of the areas corresponding to the structures, an interaction with the implant is determined for at least one structure in a patient-specific manner on the basis of the image data, the respective interaction with the implant is checked for a number of structures to see if a predefined critical load is exceeded, and the shape of the implant is defined as a manufacturing model, and the manufacturing model is stored on a data carrier and / or output via an interface if the predefined critical load is not exceeded for any of the tested interactions of the implant with the respective structure.Advantageous and, in some cases, inventive embodiments of the inventions are set out in the dependent claims and in the following description.

[0009] The method is preferably executed by a computer that has a data connection to a data storage medium and / or an interface. Preferably, image data of the body region for which the implant is intended is provided. In particular, the image data can also depict the body region with time resolution, for example, a dynamic representation of cardiac movement, if the implant is intended as a support structure in a coronary artery or as a heart valve.

[0010] For segmentation, landmarks can be used, which can also be set manually. Preferably, segmentation is also supported by machine learning algorithms, so that, for example, the image data is first classified into areas with known patterns, and areas that do not initially correspond to a known pattern are classified manually, with the pattern recognition "learning" the corresponding classification.

[0011] The term "implant" here also includes any implantation aids used for implantation that are directly connected to the implant prior to implantation. The implant's shape can be defined, in particular, by calculating the surface of a structure corresponding to a segmented area. The implant can then have at least a partial negative shape relative to the surface of the structure identified through segmentation. Specifically, the implant's shape can be predetermined by a calculation that can still be manually adjusted before determining any interaction with the respective structure.

[0012] The interaction of at least one structure with the implant includes, in particular, a load on the implant by the structure and a load on the structure by the implant.

[0013] The invention is based on the premise that patient-specific adaptation of an implant to individual anatomical conditions is best achieved by using image data of the relevant body region. It is recognized that the spatial resolution of the body region, available through the image data, can be directly used to define the shape of the implant if the image data can be segmented into areas corresponding to different tissue structures. Segmenting these areas allows for the creation of a model of the body region. By assigning individual pixels within a designated implant area to their spatial information, the shape of the implant can be defined.By defining the geometry of the implant using the spatial information of pixels from image data, a final shape can be easily translated into a data format that is directly readable by a manufacturing machine, allowing it to produce the implant directly.

[0014] In a further step, it is now recognized that for a structure previously identified to define the implant's shape by segmenting its corresponding image areas, a patient-specific interaction with the implant can be determined using the image data. Currently, the potential stresses on the implant from surrounding tissue structures are calculated using standardized models in the design of medical implants. While this allows for at least some consideration of potential stresses on the implant that could lead to wear and tear in the long term, patient-specific changes in the relevant body region are completely disregarded when determining these stresses.

[0015] However, body regions where an implant is medically necessary are often subject to significant individual anatomical deviations from the norm found in a completely healthy patient in that area. For example, vertebrae between which a disc implant is to be inserted may be worn unevenly due to prolonged misalignment and the resulting abnormal stress, which could also be considered a cause of disc damage. If the degree of wear is not taken into account when designing a disc implant, the persistent abnormal stress on the spine at that location cannot be corrected.An implant that uses the wear and tear of the vertebrae, derived from image data, only statically to define its shape, but not dynamically to determine the interaction of the vertebrae with the implant, is not optimally adapted due to the diverse movement patterns of the spine and the associated insufficient consideration of the effects of patient-specific anatomical conditions, in this case wear and tear, on movement sequences.

[0016] The consequence is, on the one hand, the risk of increased implant wear, which may necessitate premature implant replacement. This is undesirable due to the required surgical procedure. On the other hand, an implant that is not optimally adapted to the interactions can also place stress on the surrounding tissue structures. While a body region where an implant is inserted for a medical reason may experience a temporary improvement in the condition that necessitated the implant, the long-term stresses the implant exerts on the surrounding tissue structures may ultimately lead to the recurrence of the medical indication.

[0017] On the other hand, other indications such as tissue hardening or inflammation can also occur if the implant places undue stress on the tissue in the long term. With movable implants such as heart valves, a long-term loss of optimal mobility cannot be ruled out. In the worst-case scenario, an implant in which the patient's anatomical conditions are only considered statically to define the shape, but not dynamically to determine potential stresses, might temporarily alleviate the symptoms of the medical condition requiring the implant, but without effectively addressing its underlying causes in the long run.

[0018] In contrast, it is now proposed to use the segmented image data already available for defining the implant's shape to determine, patient-specifically, an interaction with the implant for at least one structure, and to check whether this interaction exceeds a predefined load – on the implant and / or the structure. If this is not the case, i.e., if no predetermined load limit is exceeded for any of the checked structures during the interaction with the implant, then the implant's shape is accepted as a valid manufacturing model and can be stored on a data carrier or output via an interface for further processing, in particular for translation into a design language readable by a manufacturing machine.

[0019] It proves advantageous to create a model of the depicted body region from the segmented areas of the image data. These segmented areas correspond to the structures of different tissues. The model is, in particular, a data model of the depicted body region, which is used to determine the interaction of at least one structure with the implant. A model of the body region depicted in the image data is especially beneficial for determining this interaction, as it allows the interaction to be determined in a patient-specific manner. This avoids disadvantages that arise from standardized load models for the implant, such as suboptimal force vectors within the implant, which could have a reciprocal effect on the surrounding tissue and thus lead to persistent stress with corresponding consequences such as irritation or inflammation.

[0020] Preferably, image data generated by at least one medical imaging procedure is provided. In particular, the image data represents a three-dimensional resolution of the relevant body region. The image data that can be provided by a conventional medical imaging procedure usually has a sufficiently high resolution for carrying out the procedure, especially for defining the shape of the implant based on the spatial data of the individual pixels.

[0021] In an advantageous embodiment of the invention, image data generated by at least two medical imaging techniques of different modalities are provided, wherein a first modality generates a set of first image data and a second modality generates a set of second image data. In particular, the at least two medical imaging techniques each have a different resolution with respect to various structures of different body tissues, such that, in particular, the first image data resolve at least a number of first structures especially well, and the second image data resolve at least a number of second structures especially well. The resolution quality can be determined, for example, by the signal-to-noise ratio or the image contrast.In particular, the at least two medical imaging procedures include an MRI and a CT scan, so that the structures well resolved by the MRI are soft tissue, and the structures well resolved by the CT scan are bone tissue. This is advantageous for determining interactions of the implant with multiple structures of different tissues.

[0022] Advantageously, a number of areas corresponding to structures are segmented in the first set of image data, and a number of corresponding areas are segmented in the second set of image data. A model of the depicted body region is then created from these segments. By using image data from different modalities, the model of the body region can represent the various structures of different tissues, each of which is well resolved by different modalities, in particularly high detail. This improves the accuracy of determining the stress caused by any interaction.

[0023] Ideally, the implant shape is defined by selecting a predefined template and modifying the template's shape based on the patient's specific image data. In particular, the template can be overlaid with a patient-specific data model of the relevant body region and adjusted according to the segmented areas. This also includes at least partial manual adjustments using graphical representations on a screen. Using a predefined template that is individually adapted to the patient's anatomy takes into account the fact that implants of the same type often deviate from a basic shape determined by average anatomy by only a few percent (relative to the total volume of the implant). However, these deviations are often crucial for the correct medical function of the implant in the patient's specific body region.

[0024] Using such a basic shape as a template and adapting it allows the shape definition to be less computationally intensive, since only the patient-specific deviations from the basic shape need to be calculated, and not the entire implant. Because the template selection can be done, for example, via simple pattern recognition, this makes it possible to limit the computationally intensive part of the shape definition to just a few percent of the implant's volume.

[0025] In a further advantageous embodiment of the invention, the interaction of at least one structure with the implant is determined by a numerical simulation. Preferably, a data model of the body region for which the implant is intended is used for the simulation. In particular, the simulation can dynamically determine the loads arising from the interaction of the implant with the structures in question, i.e., within the framework of a load model underlying the simulation, the loads occurring during various movements of the body region are simulated.

[0026] Preferably, blood flow is simulated in the simulation. This is particularly advantageous for an implant intended for a blood vessel or as a heart valve.

[0027] Advantageously, to define the manufacturing model, parameters for a critical load are specified for a number of areas of the implant and / or a number of areas of the at least one structure and compared area by area with a load determined by the simulated interaction. In particular, location-dependent parameter functions can be specified for each area, and the respective parameter function can be compared with the loads determined for these areas by the simulation, depending on their spatial coordinates. Such a procedure makes it possible, in particular, to determine by what value a permissible load is exceeded at a specific location of the implant for a given shape. This information can then be used for adjustments.In particular, the values ​​determined by the simulation for the respective location-dependent load on the implant and the surrounding structures can be used to determine the locally occurring forces.

[0028] In a further advantageous embodiment of the invention, the shape of the implant is changed if the predefined critical load is exceeded due to at least one interaction of the implant with a structure, and the interaction of the implant with the structure is then redefined based on the changed shape of the implant. This process can be iterated. If the predefined critical load is no longer exceeded for the structure in question, particularly for at least one, preferably for all adjacent structures, the current shape of the implant can be defined as a manufacturing model, and the manufacturing model can be stored on a data carrier and / or output via an interface.

[0029] Preferably, the shape of the implant is modified by using area-specific deviations of a load determined through a simulated interaction from a predefined critical load. The shape modification can be implemented particularly in areas with significant exceedances of the specified critical load values. This allows for more computationally efficient calculations for redefining the shape.

[0030] Preferably, the local density and / or local material selection of the implant is changed if at least one interaction of the implant with a structure causes the predefined critical load to be exceeded, whereby the interaction of the implant with the structure is redefined based on the changed local density and / or local material selection of the implant. In particular, this process can be iterated. If the predefined critical load is no longer exceeded for the structure in question, especially for all adjacent structures, the current local density and / or local material selection of the implant can be defined as properties of the manufacturing model, and the manufacturing model can be stored on a data carrier and / or output via an interface.

[0031] The invention further describes a device configured for carrying out the aforementioned method for generating a manufacturing model. In particular, this includes a computer, which may be equipped with at least one ASIC specifically designed for this purpose. The advantages stated for the method and its further developments can be transferred analogously to the device.

[0032] The invention also mentions a computer program with program code for carrying out the aforementioned method for generating a manufacturing model when the computer program is executed on a computer.

[0033] The invention further describes a method for manufacturing a medical implant, which comprises, as process steps, firstly, the generation of a manufacturing model using a previously described method, secondly, the generation of a design program readable by a manufacturing device based on the manufacturing model, and thirdly, the production of the implant in the manufacturing device based on the design program. A particular advantage here is that the manufacturing model can be output by the method for its generation in a data format that has a matrix-valued three-dimensional volume representation of the implant, such as a CAD file.

[0034] Such a representation can be directly translated into a machine-readable design program for a variety of manufacturing devices, such as a 3D printer or a milling machine. This program can include the necessary manufacturing instructions for the device, such as an .stl file in the case of a 3D printer. This ensures a high degree of probability for the output manufacturing model and its practical usability. In particular, outputting the model in a suitable file format allows the creation of the manufacturing model to be separated from the physical production of the implant, which can simplify the manufacturing process.

[0035] An embodiment of the invention is explained in more detail below with reference to a drawing. The drawing schematically depicts:

[0036] Fig. 1. In a block diagram, show the process flow of a procedure for generating a manufacturing model for a medical implant,

[0037] Fig. 2. In a block diagram, the sequence of a process for manufacturing a [product / service] according to... Fig. 1 designed medical implant,

[0038] Fig. 3 first image data from a body region of the spine,

[0039] Fig. 4 second image data from a body region of the spine,

[0040] Fig. 5 in a longitudinal section view, a simulation of an interaction of an implant with surrounding tissue based on the image data according to Fig. 3 and Fig. 4, and

[0041] Fig. Figure 6 shows a cross-sectional view of a simulation of the interaction of a heart valve implant with the surrounding tissue.

[0042] Corresponding parts and sizes are marked with the same reference symbols in all figures.

[0043] In Fig. In a block diagram, 1 schematically represents a procedure. 1 to generate a manufacturing model 2 for a medical implant. In the present case, a set of initial image data is obtained using two medical imaging procedures: CT and MRI, specifically computed tomography (CT) and magnetic resonance imaging (MRI). 6 and a set of second image data 8 provided. Another implementation variant of the procedure, not shown here. 1 A process similar to that in which image data is provided by only one medical imaging procedure. The initial image data 6 and the second image data 8They are segmented separately from each other. This means that contiguous areas within the individual image data are not segmented. 10 , 12 Based on specific homogeneity criteria, the respective structures are determined. 11 , 13 depict the same tissue. In the present case, the areas correspond to 10 , which are in the initial image data provided by the CT scan 6 to be segmented, structures 11 from bone tissue, as this is particularly well resolved by CT. The areas 12 , which are in the second image data provided by the MRI 8 segmented, they form corresponding structures 13 of soft tissue of the affected body region 14 away.

[0044] From the data in the first image 6 segmented areas 10 and the one in the second image data 8 segmented areas 12A virtual model will now be used. 16 the depicted body region 14 created. Based on this model 16 A form will now be formed 18 for the implant to be manufactured. This is first defined by pattern recognition in the model. 16 From a set of predefined templates, the one that most closely resembles the shape of the implant to be manufactured is selected. The selected template 20 The image data will then be used 6 , 8 directly or indirectly, i.e., based on the segments derived from it 10 , 12 generated model 16 , modified to suit the patient's specific needs. Within the framework of the model 16 or the image data generating it 6 , 8 will now be used for the defined form 18 Possible interactions of the implant 22 with the structures surrounding the implant 11 , 13in a numerical simulation 24 determined. The simulation 24 It calculates, with spatial resolution, the effects of an interaction using mechanical load models. 22 during movements of the body region 14 on the implant of the shape 18 and the structures surrounding it 11 , 13 have, and determines local load parameters in each case. 25 .

[0045] If a predefined critical load occurs 26 through the respective local load parameter 25 If the form is exceeded, the 18 based on the determined local load parameters 25 – in particular based on the respective degree to which the critical load is exceeded 26 through the local load parameter 25 – modified, and the simulation 24 for the interactions 22This process is repeated. It will now be iterated until the critical load is reached. 26 for the entire body region 14 and the implant remains below the required depth. The form thus determined to be permissible 18 The implant is used as a manufacturing model. 2 for the implant, and can now be stored on a data carrier 30 saved or via an interface 32 will be issued.

[0046] In Fig. 2 is a schematic representation of the sequence of a procedure in a block diagram. 40 for the production of a according to Fig. 1 designed medical implant 42 depicted. After the in Fig. 1. The previously described procedure 1 is run on a specially designed computer 43 a manufacturing model 2 for the implant 42 generated, and via an interface 32 issued. The manufacturing model 2will now be entered into a design program 44 translated, which is from a production device, which here is a 3D printer. 46 The data is given and can be read directly, for example, into a file in .stl format. The 3D printer 46 The implant now produces 42 based on the design program 44 , which is a direct implementation of the manufacturing model 2 represents.

[0047] In Fig. 3 and Fig. 4 is schematically the same longitudinal section plane of a section of a spine in the first image data. 6 and in second image data 8 shown which two vertebrae 50 , 52 and an intervertebral disc in between 54 depict. In the in Fig. 3 first image data shown 6 are the two vortices involved 50 , 52 The high contrast makes it particularly easy to see in the Fig. 4 second image data shown 8 is the intervertebral disc 54 and the spinal cord behind it 56 better resolution. In the first image data, the lower vortex can be seen. 52 a slight bulge 58 recognize which deviates from a normally expected shape 60 of the same vertebra in an average person. This is the shape that is usually expected. 60 The bulge is shown with a dashed line for clarity and is not part of the image data. 58 It can be congenital or result from years of incorrect posture or strain due to wear and tear. In the second image data... 8 It is evident that the spinal cord 56 near the bulge 58 at the vertebrae 50 , 52 passes by.

[0048] In Fig. 5 is schematically a simulation24 an interaction 22 an implant 42 with the surrounding structures 11 shown. Based on the image data 6 , 8 after Fig. 3 and Fig. 4 is a model for this. 16 the corresponding body region, which includes the vertebrae 50 , 52 , the intervertebral disc 54 and the spinal cord 58 It encompasses, has been created. The intervertebral disc 54 will now be in the model 16 for a numerical simulation 24 the interaction 22 through the implant 42 replaced with a predefined form.

[0049] The interaction 22 This consists of a curvature of the spine. Through simulation 24 the interaction 22 The load on the implant will now be determined in each case. 42 during the interaction 22calculated. It is determined that if the patient moves in a way that results in the corresponding curvature of the spine, the implant 42 due to the bulge 58 , which represents an individual anatomical peculiarity, stronger forces in the direction of the spinal cord 56 have an effect, and a critical load 26 in the area 64 The implant's diameter is exceeded. This can, in the long term, lead to either a protrusion of the implant or a protrusion of the implant. 42 or its excessive wear and tear as a result of friction with the vertebrae 50 , 52 lead to this. In the present case, the shape of the implant would 42 based on the simulation 24 The insights gained were adapted, and the interaction 22 (and possibly others) again for critical stresses on the implant. 42 These will now be checked as a result of the changed shape of the implant. 42The implant can no longer be used in a way that does not exceed the defined shape. 42 be defined and output as a manufacturing model.

[0050] In Fig. Figure 6 is a simulation in a cross-sectional view. 24 an interaction 22 a heart valve implant 42 with the surrounding tissue 66 shown. The interaction 22 This essentially consists of the effects of opening and closing the heart valve implant. 42 from the surrounding tissue 66 For the simulation 24 This results in a blood flow 68 taken into account. For example, the aorta shows 70 , into which the implant 42 to be used, a narrowing 72 For example, excessive blood flow could occur. 68This could increase blood pressure in this area, potentially leading to long-term health problems for the patient. In this particular case, the shape of the implant may be relevant. 42 to the requirements of blood flow 68 , which result from the individual anatomy of the patient, especially his aorta 70 result, be adjusted.

[0051] Although the invention has been illustrated and described in detail by means of the preferred embodiment, the invention is not limited by this embodiment. Other variations can be derived from it by a person skilled in the art without departing from the scope of protection of the invention. QUOTES INCLUDED IN THE DESCRIPTION

[0052] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0053] WO 2004 / 110309

[0004] WO 2014 / 036551

[0004]

Claims

[1] Procedure ( 1 ) to generate a manufacturing model ( 2 ) for a medical implant ( 42 ), where – Image data ( 6 , 8 ) of a body region ( 14 ) will be provided, – in the image data ( 6 , 8 ) areas ( 10 , 12 ) are segmented, each of which contains structures ( 11 , 13 ) correspond to different tissues, – based on the structures ( 11 , 13 ) corresponding areas ( 10 , 12 ) a form ( 18 ) of the implant ( 42 ) is defined, – for at least one structure ( 11 , 13 ) patient-specific based on the image data ( 6 , 8 ) an interaction ( 22 ) with the implant ( 42 ) is determined, – for a number of structures ( 11 , 13) the respective interaction ( 22 ) with the implant ( 42 ) upon exceeding a predefined critical load ( 26 ) is being checked, and – the shape ( 18 ) of the implant ( 42 ) as a manufacturing model ( 2 ) is defined, and the manufacturing model ( 2 ) on a data carrier ( 30 ) stored and / or via an interface ( 32 ) is output if no checked interaction ( 22 ) of the implant ( 42 ) with the respective structure ( 11 , 13 ) the predefined critical load ( 26 ) is exceeded. [2] Procedure ( 1 ) according to claim 1, wherein the segmented areas ( 10 , 12 ) the image data ( 6 , 8 ) a model ( 16 ) of the depicted body region ( 14 ) is created. [3] Procedure ( 1) according to claim 1 or claim 2, wherein image data generated by at least one medical imaging procedure (CT, MRI) 6 , 8 ) will be provided. [4] Procedure ( 1 ) according to claim 3, wherein image data generated by at least two medical imaging procedures (CT, MRI) of different modalities ( 6 , 8 ) are provided, and wherein a first modality (CT) provides a set of initial image data ( 6 ) and through a second modality (MRI) a set of second image data ( 8 ) is generated. [5] Procedure ( 1 ) according to claim 4, where in the first image data ( 6 ) a number of structures ( 11 ) corresponding areas ( 10 ) is segmented, where in the second image data ( 8 ) a number of structures ( 13 ) corresponding areas ( 12 ) is segmented, and from the areas ( 10 ) the first image data ( 6 ) and the areas ( 12 ) the second image data ( 8 ) a model ( 16 ) of the depicted body region ( 14 ) is created. [6] Procedure ( 1 ) according to one of the preceding claims, wherein a form ( 18 ) of the implant ( 42 ) is defined by using a predefined template ( 20 ) is selected, and the shape of the template ( 20 ) based on the image data ( 6 , 8 ) is modified to suit the patient. [7] Procedure ( 1 ) according to one of the preceding claims, wherein for the at least one structure ( 11 , 13 ) the interaction ( 22 ) with the implant ( 42 ) by a numerical simulation ( 24 ) is determined. [8] Procedure ( 1 ) according to claim 7, wherein in the simulation ( 24) further blood flow ( 68 ) is simulated. [9] Procedure ( 1 ) according to claim 7 or claim 8, wherein the manufacturing model is defined by ( 2 ) for a number of areas ( 64 ) of the implant ( 42 ) and / or a number of areas of at least one structure ( 11 , 13 ) each parameter for a critical load ( 26 ) specified and area-wise with a simulated interaction ( 22 ) determined load ( 25 ) can be compared. [10] Procedure ( 1 ) according to any of the preceding claims, where the form ( 18 ) of the implant ( 42 ) is changed if at least one interaction ( 22 ) of the implant ( 42 ) with a structure ( 11 , 13 ) the predefined critical load ( 26 ) is exceeded, and where the interaction ( 22) of the implant ( 42 ) with the structure ( 11 , 13 ) based on the changed form ( 18 ) of the implant ( 42 ) is determined again. [11] Procedure ( 1 ) according to claim 10, wherein to change the shape ( 18 ) of the implant ( 42 ) region-specific deviations of a simulated interaction ( 22 ) determined load ( 25 ) from a predefined critical load ( 26 ) are used. [12] Procedure ( 1 ) according to any of the preceding claims, including a local density and / or a local material selection of the implant ( 42 ) is changed if at least one interaction ( 22 ) of the implant ( 42 ) with a structure ( 11 , 13 ) the predefined critical load ( 26 ) is exceeded, and where the interaction ( 22) of the implant ( 42 ) with the structure ( 11 , 13 ) based on the changed local density and / or local material selection of the implant ( 42 ) is determined again. [13] Device ( 43 ), which are used to carry out the procedure ( 1 ) to generate a manufacturing model ( 2 ) is set up according to one of the preceding claims. [14] Computer program with program code for carrying out the procedure ( 1 ) to generate a manufacturing model ( 2 ) according to one of claims 1 to 12, if the computer program is on a computer ( 43 ) is executed. [15] Procedure ( 40 ) for the manufacture of a medical implant ( 42 ), which includes the following procedural steps: – Creation of a manufacturing model ( 2 ) by means of a procedure ( 1 ) according to any one of claims 1 to 12, – Generating a product from a producing device ( 46 ) readable design program ( 44 ) based on the manufacturing model ( 2 ), and – Creating the implant ( 42 ) in the producing device ( 46 ) using the design program ( 44 ).

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