3D printing implant with internal channel

Abstract

An implant (52) for insertion into a patient is provided. The implant includes a layer of a three-dimensionally printed structure. Each layer includes a filling pattern of a three-dimensionally printed structure, the filling pattern of each layer including a set of filling lines. The implant comprises a plurality of hollow channels (21). The layers are arranged atop each other such that a plurality of hollow channels are formed within the implant, with the walls of each channel being formed by segments of fill lines of a plurality of of the layers of the printed structure. At least one hollow channel (21) extends between a first outer surface of the implant and a second outer surface of the implant. The at least one hollow channel is oriented in a direction inclined with respect to a reference axis (37) perpendicular to the first outer surface of the implant.

Description

[0001] This application is a divisional application of the patent application with international application number PCT / EP2019 / 065264, international application date June 12, 2019, Chinese national application number 201980052584.8, and title “3D printed implant with internal channel”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority of European patent application 18177214.6 filed in the European Patent Office on June 12, 2018, the entire contents of which including all tables, drawings and claims are incorporated herein by reference for all purposes. Technical Field

[0004] The present invention relates to the field of implants, in particular, to 3D (three-dimensional) printed implants with internal channels and their manufacture. Background Art

[0005] Today, breast enhancement and breast regeneration surgery are one of the most commonly performed surgeries for aesthetic reasons. Since aesthetic aspects play an important role in breast surgery, one of the biggest concerns of women undergoing surgery is the appearance of the final result. In fact, the aesthetic aspect is crucial to the patient's psychological condition, especially for women who experience breast cancer and the result is that part of the natural breast tissue is removed. Therefore, the attention to this field has increased over time. At present, even if different breast reconstruction or breast enhancement procedures are adopted, both operations mainly rely on the insertion of silicone implants. Fat transplantation is also a common technique, and the combination of these two operations can be used to improve the final result, and in particular, to meet the aesthetic expectations of patients.

[0006] However, despite its prevalence in plastic surgery, silicone implants are known to sometimes have problems related to the appearance of the breasts after the surgery related to an unnatural appearance or large scars, depending on the size of the implant inserted. In addition, a major problem associated with silicone implants is their limited life span. Since they are not a lifelong product, after a certain period of time, the implants can burst inside the body. Another complication caused by the body's immune response to the foreign implant material in the form of capsular contracture can occur, which affects the firmness of the breast, resulting in an unnatural tactile sensation. Even if there are non-surgical methods for treating the capsule, the patient most often has to undergo a second surgery to remove or replace the implant.

[0007] In order to overcome the problems associated with silicone implants, in particular to improve patient safety, a new generation of bioresorbable implants has been considered, the purpose of which is to support the regeneration of tissue inside the body. Biodegradable materials, such as some thermoplastics, can be manufactured using a technique called injection molding, in which the molten material is injected into a mold that gives the object its overall shape. Unfortunately, this process shows limitations when complex detailed geometries need to be created. For example, in regenerative medicine, high porosity structures must be used as templates to promote tissue regeneration.

[0008] Recently, mainly due to the rapid development of 3D printing technology, this technology has been considered for use in the manufacture of implants. 3D printers usually create 3D objects through an additive process. More commonly known as "3D printing", additive manufacturing (AM) is a canopy term for a group of technologies that build physical parts by extruding materials layer by layer, a process inherently different from classical machining, which most commonly works by drilling, milling blocks of material, etc.

[0009] The above-mentioned breast implants can be manufactured using 3D printing (specifically fused deposition modeling (FDM) technology) and biodegradable materials such as polycaprolactone (PCL). This particular polymer can be advantageous because it is widely used in the medical field and has therefore been approved by regulatory agencies. Most importantly, PCL meets the degradation requirements so that once it begins to degrade, new tissue / vasculature will grow and settle within the implant.

[0010] After inserting the implant made by 3D printing, fat injection needs to be performed. Fat injection is necessary because it has been observed that the regenerated tissue that "regrows" inside the implant is harder than the natural breast tissue. Therefore, in order to make the final result as soft as the natural breast tissue, a suitable percentage of fat can be collected, for example, by means of liposuction, and injected into the implant using a specific needle. Injection surgery is problematic in the sense of random injection, which can damage the filaments and affect the integrity of the overall structure of the implant. In order to overcome this problem, a surgery disclosed in European patent application EP2995278A1 for designing implants and the implant itself is conducive to fat injection can be used. The surgery described in EP2995278A1 involves the insertion of an implant to promote tissue regeneration inside the body and to promote subsequent fat injection within a certain period of time after implantation. In order to avoid damage to the implant, a space for inserting a needle for fat injection should be provided. For this reason, the implant disclosed in EP2995278A1 comprises a three-dimensional scaffold structure, which has a gap, and the gap is filled with a structure that occupies the space, and the structure that occupies the space is removably attached to the three-dimensional scaffold structure. The structure that occupies the space is provided to prevent tissue and / or single cells from invading the gap. After removing the structure that occupies the space in the second operation, the gap (which is preferably interconnected and forms a continuous channel structure) produced can be filled with fat or other transplanted cells.

[0011] However, the design of the corresponding 3D implant is quite challenging from a manufacturing point of view and is quite undesirable from the patient and surgeon's point of view. In fact, the channel formed after the removal of the space-occupying structure needs to be taken into account during the printing of the 3D implant and therefore needs to be included in the printing instruction code which may lead to a weakened structure. In addition, the subsequent removal of the space-occupying structure requires an additional surgery and may bring complications, because the newly regenerated tissue may be damaged, leading to patient safety issues, and if the fat is not well embedded in the structure due to the difference between the predicted void space volume and the actual volume of the injected fat, the injected fat may undergo necrosis or it may be resorbed.

[0012] Therefore, there is a need in the art for an improved implant that improves the final outcome and at the same time facilitates the overall procedure directed at rebuilding lost tissue and / or restoring tissue / organ function. Summary of the invention

[0013] In various embodiments, the present invention relates to an implant comprising layers of a three-dimensional structure, each layer comprising a filling pattern; wherein the layers are arranged on top of each other so that a plurality of hollow channels are formed within the implant, wherein each hollow channel is oriented in a direction inclined relative to the direction in which the layers are arranged on top of each other. The walls of each channel are formed by segments of the filling pattern, in particular by filaments or strips of printed material. Within the scope of this specification, parts or segments of thermoplastic raw material extruded by a printer when making the filling pattern of a layer will be referred to as filaments.

[0014] The implant according to the present invention aims to overcome the above-mentioned problems, in particular to facilitate the injection of biomaterials such as adipose tissue into the implant and to remove the necessity of a second operation to create a void for injecting the biomaterial. In the following, without loss of generality, only fat or adipose cells / tissue will be referred to as representative and highly relevant forms of biomaterials that can be injected into the implant. However, it should be understood that any other type of cells or biomaterials can be injected into the implant, depending on its use.

[0015] The implant architecture of the present invention utilizes channels that are naturally generated during the manufacture of the implant and therefore already exist in machine instructions (e.g., G codes). In this way, fat can be injected into the channels formed natively in the implant without damaging any of its filaments. For this reason, since the 3D printed implant presents a highly porous structure, the implant is designed so that the existing channels extending through the implant coincide with the channels for fat injection. The channels of the implants according to various embodiments (which are usually developed along the printing direction in conventional 3D printed objects) are oriented. The oriented channels do not have to be parallel to the printing direction. Preferably, as will be described later, the channels can additionally focus on the area where the surgeon can inject fat into the implant. Therefore, the natural structure of the implant (particularly the path / channel formed therein) can be used to inject fat into the implant without damaging the implant itself. In particular, there is no need to provide additional or dedicated channels in the design of the implant and therefore the space-occupying structure known from EP2995278A1 that needs to be adopted.

[0016] As used in the present application, the term "implant" relates to a medical device, which is used to replace the missing biological structure, to support the damaged biological structure and / or to enhance the existing biological structure. In particular, the implant of the present invention is an implant for rebuilding body tissue and / or restoring the function of tissue or organ. Although the implant will be described as an implant for breast reconstruction or breast enhancement in the description, the implant can be filled with any required biomaterial and can be used at different parts of the body. Preferably, the implant can be printed by biodegradable materials. Suitable materials for this purpose can be any thermoplastic and biocompatible or biodegradable materials. For example, the material can include but is not limited to polycaprolactone (PCL), polyglycolide, polylactide and / or at least two or more materials (to) polymer.

[0017] Various embodiments relate to an implant for insertion into a patient. The implant comprises layers of a three-dimensional (3D) printed structure. Each layer comprises a fill pattern of the three-dimensional printed structure. The fill pattern of each layer comprises a set of fill lines. The implant also comprises a plurality of hollow channels. The layers are arranged on top of each other so that a plurality of hollow channels are formed within the implant. The walls of each channel are formed by segments of the fill lines of a plurality of layers in the layers of the printed structure. At least one hollow channel extends between a first outer surface of the implant and a second outer surface of the implant. At least one hollow channel is oriented in a direction inclined relative to a reference axis perpendicular to the first outer surface of the implant.

[0018] In various embodiments, the first outer surface and the second outer surface of the implant are oppositely facing surfaces.

[0019] In various embodiments, the first outer surface is parallel to a two-dimensional plane formed by the first layer of the three-dimensional (3D) printed structure.

[0020] In various embodiments, the first outer surface is the largest planar surface of the implant.

[0021] In various embodiments, the angle between the longitudinal axis of the channel and the reference axis is between 10 degrees and 85 degrees.

[0022] In various embodiments, the layers of a three-dimensional (3D) printed structure include a first batch of layers and a second batch of layers. The first batch of layers includes odd-numbered layers in the layers of the three-dimensional (3D) printed structure, and the second batch of layers includes even-numbered layers in the layers of the three-dimensional (3D) printed structure. Fill lines of the first batch of layers are oriented in a first direction, and fill lines of the second batch of layers are oriented in a second direction different from the first direction. Portions of the fill pattern of the odd-numbered layers in the first batch of layers are displaced relative to portions of the fill pattern of the first fill layer in the first batch of layers.

[0023] In various embodiments, portions of the fill pattern of even-numbered layers in the second batch of layers are shifted relative to portions of the fill pattern of first fill layers in the second batch of layers.

[0024] In various embodiments, the lateral offset value between the first fill line of the first odd-numbered layer and the first fill line of the second odd-numbered layer is between 0% and 50% of the distance between the first fill line of the first odd-numbered layer and the second adjacent fill line of the first odd-numbered layer.

[0025] In various embodiments, for values ​​of t less than or equal to 2, the lateral offset value between the first fill line of the n+2*t odd-numbered layer and the first fill line of the first odd-numbered layer is less than the distance between the first fill line of the first odd-numbered layer and the second adjacent fill line of the first odd-numbered layer.

[0026] In various embodiments, the lateral offset value between the first fill line of the first odd-numbered layer and the first fill line of the second odd-numbered layer is between 50% and 100% of the distance between the first fill line of the first odd-numbered layer and the second adjacent fill line of the first odd-numbered layer.

[0027] In various embodiments, for values ​​of t greater than or equal to 2, the lateral offset value between the first fill line of the n+2*t odd-numbered layer and the first fill line of the first odd-numbered layer is greater than the distance between the first fill line of the first odd-numbered layer and the second adjacent fill line of the first odd-numbered layer.

[0028] In various embodiments, the plurality of hollow channels converge towards a predefined area at a first outer surface or at a second outer surface of the implant.

[0029] In various embodiments, the predefined area is a convergence point located outside the first outer surface or outside the second outer surface of the implant.

[0030] In various embodiments, at least one hollow channel is a tapered channel.

[0031] In various embodiments, the tapered channel is configured such that the size of the opening of the channel on the bottom surface of the implant is in the range of 5-10 mm and the size of the opening of the channel on the top surface of the implant is in the range of 0.5-5 mm.

[0032] In various embodiments, more than two hollow channels of the plurality of hollow channels are inclined at the same angle relative to the reference axis.

[0033] In various embodiments, at least 10% of the hollow channels in the plurality of hollow channels are inclined at the same angle relative to the reference axis.

[0034] In various embodiments, at least one hollow channel of the plurality of hollow channels comprises a first opening at a first outer surface of the implant and a second opening at a second outer surface of the implant.

[0035] In various embodiments, at least one hollow channel of the plurality of hollow channels comprises an inclined portion and at least one non-inclined portion, wherein the non-inclined portion of the channel comprises one or more outermost layers of the implant.

[0036] In various embodiments, the non-inclined portion of the implant is located between the opening of the channel of the first outer surface of the implant or the second outer surface of the implant and the inclined portion of the implant.

[0037] In various embodiments, the layers of a three-dimensional (3D) printed structure include a first batch of layers and a second batch of layers. The first batch of layers includes odd-numbered layers in the layers of the three-dimensional (3D) printed structure. The second batch of layers includes even-numbered layers in the layers of the three-dimensional (3D) printed structure. The first wall of the hollow channel is formed by segments of multiple odd-numbered layers in the first batch of layers. The second wall of the hollow channel is formed by segments of multiple even-numbered layers in the first batch of layers.

[0038] In various embodiments, the perimeter of each layer is determined by a slice of the projected 3D model of the implant. The fill pattern of each layer is defined by the perimeter so that when the layers are arranged on top of each other, the implant has a 3D form similar to the 3D model of the implant.

[0039] In various embodiments, the fill pattern of each layer includes a continuous meander of printed material from a starting point of the layer to an end point of the layer.

[0040] Various embodiments relate to a method for forming an implant. The method includes sequentially printing layers to form a three-dimensional (3D) printed structure, wherein each layer is printed according to a fill pattern, and the fill pattern of each layer includes a set of fill lines. The layers are printed on top of each other so that multiple hollow channels are formed in the implant. The wall of each channel is formed by the segmentation of the fill lines of multiple layers in the layers of the printed structure. Each hollow channel extends between a first outer surface of the implant and a second outer surface of the implant, wherein each hollow channel is oriented in a direction inclined relative to a reference axis perpendicular to the first outer surface of the implant.

[0041] In various embodiments, the method further includes providing a channel direction vector, the channel direction vector defining the inclination of the channel to be formed; specifying a hole size of a first hole of a layer to be formed at a first height, wherein the first hole is represented by a first line segment. The method further includes specifying a hole size of a second hole of a layer to be formed at a second height, wherein the second hole is represented by a second line segment, the first hole and the second hole belonging to the same channel to be formed.

[0042] In various embodiments, the method also includes calculating a first orientation line by connecting the left endpoints of the first line segment and the second line segment; calculating a second orientation line by connecting the right endpoints of the first line segment and the second line segment, the direction vector being located on the second orientation line; and calculating the intersection of the first orientation line and the second orientation line to determine a convergence point of the channel to be formed.

[0043] In various embodiments, the point of convergence is located outside the first outer surface or outside the second outer surface of the implant to be formed.

[0044] In various embodiments, the three-dimensional structure of interconnected layers constituting the implant can be a scaffold structure, which includes individual layers stacked on each other. By gradually changing the shape of the layers stacked on each other, the 3D implant can be given its desired form. The 3D scaffold structure of the implant can basically include channels or holes arranged adjacent to each other and separated from each other by walls. The distance or spacing between adjacent channels can be the same from the bottom layer to the top layer of the channel. For example, the distance separating adjacent channels can be the thickness of the filling line. The wall of the channel can include filaments (or parts thereof) of every other (alternating) layer. For example, the first wall of the channel can include filaments from the first filling line of the odd-numbered layer. The second wall of the same channel can include filaments from the second filling line of the odd-numbered layer. The third wall of the same channel can include filaments from the first filling line of the even-numbered layer. The fourth wall of the same channel can include filaments from the second line of the even-numbered layer. The first channel can be formed between the first filling line of the odd-numbered layer and the second filling line of the odd-numbered layer. The second adjacent channel can be located between the second filling line of the odd-numbered layer and the third filling line of the odd-numbered layer. Typically, for example, the filling pattern of the layer can be a design parameter and can be configured according to the mechanical requirements of the implant. According to various embodiments, the filling pattern of the layer can include parallel strips / filaments (i.e., parts of the material), and the filling pattern of layer n and layer n+2 can be similar. The filling layer of the implant can be configured so that, depending on the individual design of the 3D implant, the strips of a specific layer and the strips of the continuous layer form an angle (e.g., at least 10 °, preferably at least 30 °, more preferably at least 45 °, more preferably at least 60 °, more preferably 90 °) less than 90 °. In other words, the strips of a specific layer can cover the strips of the continuous layer at a certain angle. The connection points between the strips of adjacent layers correspond to the interconnection points between the layers and provide structural integrity for the implant. In this way, each layer is interconnected to its preceding layer and its following layer.

[0045] Arrangement of layers on top of each other, wherein the strips / portions of the fill pattern of layer n are parallel to the strips or portions of layer n+2, so that the strips are arranged offset above each other when viewed in the printing direction of the implant (i.e., in the direction in which the layers are stacked on each other). Such a configuration results in the formation of holes or channels that are inclined and extend through the implant non-parallel to the printing direction. Thus, each channel that starts at the bottom (surface) of the implant (i.e., the first layer printed) and ends at the top (surface) of the implant (i.e., the last layer or portion thereof printed at a given position on the surface of the implant) is oriented in a direction that is inclined relative to the printing direction.

[0046] According to various embodiments, the channel size can be constant, that is, the cross section of the channel at the level of any layer of the implant can be the same. In this case, the cross section of the channel corresponds to the geometry of the opening of the channel at the bottom of the implant and the geometry of the opening of the channel at the top of the implant. In those embodiments, the angle of inclination (i.e., the angle between the plane of the first printed layer and the axis extending through the channel parallel to each of its walls) can be the same for each channel of the implant. In other words, each channel of the implant can be regarded as a hollow channel, which forms a connection between the opening in the bottom surface of the implant and the opening in the top surface of the implant, wherein the channel does not extend perpendicular to the bottom surface but is inclined in a specific direction.

[0047] According to various embodiments of implant, each in hollow passage can comprise the corresponding first opening that is arranged on the top surface of implant substantially, and each in opening corresponds to the end of passage.The opening of passage does not necessarily have to be located in the plane parallel to the implant layer.In the sense that the outermost strip or strand of the printed material of the channel wall that limits the opening of passage can belong to different layers, the opening of passage can be skewed.As understood herein, even if some filaments or strands of material extend in its cross section, passage is also considered to be hollow and open.When viewed from the top or from the bottom (that is, along the axis running through passage), being interspersed with filament passage is still considered to be hollow, because the single filament extending between the corners of passage does not affect the ability of passage transmission to be injected into the fat in passage.

[0048] According to various embodiments of the implant, each hollow channel can extend between a first opening disposed on the top surface of the implant and a second opening disposed on the bottom surface of the implant. The bottom surface of the implant may correspond to a first layer printed during manufacture of the implant. The top surface of the implant may be defined by a layer or portion of a layer (e.g., a filament) having only one adjacent layer (as opposed to an inner layer or portion of a layer having two adjacent layers (one below and one above)).

[0049] According to various embodiments of the implant, any of the walls of the hollow channel may be formed by segments (e.g., strips of printed material) of every other (alternating) layer in the arrangement of the layers forming the implant. The filling pattern of the layer can be designed so that any two adjacent layers of printed material form a vertical and horizontal intersection pattern, so that the filaments or strips of the printed material layers intersect at a certain angle (e.g., 90 °). Therefore, the wall of the channel may include, for example, every other layer of filaments or strips that may be parallel to each other. Due to the vertical and horizontal intersection pattern of the filaments forming the 3D implant, the filaments of the layer between the two layers that contribute to the filaments of a given wall are usually arranged at an angle (e.g., 90 °) relative to the filaments of the two layers, and therefore do not form part of the wall. The filaments of the layer forming any wall of a given channel may be straight or curved lines of printed material. It is understood that the term fill line is not necessarily limited to a straight line, but may also include, for example, curved lines, zigzag lines, and / or undulating lines.

[0050] According to various embodiments of the implant, at least one hollow channel can be a tapered channel. The tapered channel is characterized in that its cross section gradually increases or decreases from the bottom opening of the channel to the top opening of the channel. In other words, the size (area) of the top opening and the bottom opening of the tapered channel is different because the size of the channel changes along its orientation direction. According to various embodiments of the implant, at least one tapered channel may converge toward the top surface of the implant. According to various alternative embodiments, at least one tapered channel may diverge toward the top surface of the implant. Depending on the configuration of the tapered channel (convergence or divergence), even if the amount of openings on the top and bottom surfaces may be the same, the area of ​​the bottom surface may also be different from the area of ​​the top surface size. Advantageous embodiments of the implant may have a plurality of tapered channels, wherein the tapered channels may be of a converging, diverging or mixed type. According to other embodiments, all channels of the implant may be tapered channels, preferably of the same type (convergence or divergence).

[0051] Embodiments of implants with tapered channels may include a larger opening on the muscle-facing side of the implant, the larger opening being the highest source of blood vessels, wherein, without loss of generality, the size of the implant facing the muscle is referred to as the bottom side or bottom surface. This configuration of the implant according to the present invention facilitates implant vascularization and injection of fat. Channels focused on a specific area of ​​the implant surface (e.g., the anterior lower side of the implant in the case of a breast implant) are easier to use for surgery because the channels provide guidance relative to injecting fat into the implant. Specifically, the direction of the channel in the implant can be selected so that fat can be injected from below the breast fold (inframammary injection). In addition, the implant is also more comfortable to use for surgery during fat injection surgery because the area where the fat is injected is locally limited to a specific area. Last but not least, the number of incisions and scars associated with the surgery can be reduced by using the same inframammary incisions used for implant insertion and fat injection / transplantation to reduce the number of scars when applicable.

[0052] Implants according to the invention with different channel openings can also be used to provide implants with inhomogeneous mechanical properties in particular in the printing direction, since areas with smaller channel openings tend to be stiffer than areas with larger channel openings.

[0053] A particularly useful embodiment of the implant may be one in which the channels are both tapered and skewed / inclined. In particular, in this embodiment, all channels may be converging or diverging. This configuration of the channels of the implant allows the top opening of the channels to be "focused" or directed to a predefined area on the top surface of the implant.

[0054] According to various embodiments, an implant having a tapered channel may be configured such that the size of the opening of the channel on the top surface of the implant (i.e., the opening of the channel away from the chest wall in the case of a breast implant) may be in the range of approximately 0.5-5 mm, and the size of the opening of the channel on the bottom surface of the implant (i.e., the opening of the channel facing the chest wall in the case of a breast implant) may be in the range of approximately 5-10 mm. In further embodiments, the size of the opening of the tapered channel on the bottom surface may be in the range of approximately 6-9 mm, and the size of the opening of the tapered channel on the top surface may be in the range of approximately 1-4 mm. In further embodiments, the size of the opening of the tapered channel on the bottom surface may be in the range of approximately 7-9 mm, and the size of the opening of the tapered channel on the top surface may be in the range of approximately 2-3 mm. In further embodiments, the size of the opening of the tapered channel on the bottom surface may be in the range of approximately 8-9 mm, and the size of the opening of the tapered channel on the top surface may be in the range of approximately 3-4 mm. The specified dimensions may relate to a channel having a square cross-section.

[0055] The implant of the present invention provides several advantages over implants known in the prior art. First, since the "natural" channel of the implant is used to inject and store fat, and in particular, there is no need for a structure that takes up space, the implant according to the present invention can be manufactured using only one material. On the one hand, this reduces the risk of contamination between different materials. On the other hand, problems associated with reduced bonding strength between strands / filaments of different materials can be avoided because the final product can be manufactured by a single material. Using a single material and therefore using a single filling / printing pattern for manufacturing an implant reduces the effort involved in manufacturing because it is easier to print the resulting structure using FDM technology. Another advantage from the patient's perspective in particular is that the entire surgical procedure is greatly facilitated by removing the need for additional surgery to form a space for fat injection from the implant. Therefore, the trauma of the tissue can be greatly reduced. The fact that there is no need to remove anything from the implant after the implant has been inserted into the patient also provides better biological performance, because the regenerated tissue will not be disturbed, so that the fat directly injected into the channel naturally provided in the implant will be well embedded in the regenerated tissue. Last but not least, by adapting the internal structure of the implant's channels to the site of use, an optimal layout can be found where the channels converge to the desired point or area on the surface of the implant, so that only one small incision is needed for both procedures (implant insertion and fat injection).

[0056] Additional embodiments of the present invention will now be described in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Shown are the steps performed during the manufacture of a 3D printed implant.

[0058] Figure 2 A schematic top view of a 3D printed implant (right) and an isolated view of the channels within the implant (left) are shown.

[0059] Figure 3 Various views of a general exemplary form of an implant (left column), an exemplary implant (middle column), and an implant according to various embodiments having different orientations of the internal passageway (right column) are shown.

[0060] Figure 4 Schematic diagrams of split tapered channels of an implant are shown in accordance with various embodiments.

[0061] Figure 5 Shown are general exemplary forms of implants (left column) and different views of exemplary implants having oblique tapered channels according to various embodiments.

[0062] Figure 6 Two different implants are shown according to various embodiments.

[0063] Figure 7 Two exemplary layers of an implant of various embodiments manufactured according to 3D printing are shown.

[0064] Figure 8 A modeling space for calculating a printing path according to the method of the present invention is shown.

[0065] Fig.9A and 9B Calculation of concentration points of channels of a 3D model is shown.

[0066] Fig.10 The segmentation of the 3D model into layers is shown.

[0067] Fig.11 Shows the filling of the layers of the 3D model.

[0068] Fig. 12A and 12B The calculation of the boundary area of ​​the 3D model is shown.

[0069] Fig.13A A cross-sectional side view of an implant according to various embodiments is shown.

[0070] Fig. 13B A cross-sectional side view of an implant including an inclined / skewed hollow channel according to various embodiments is shown.

[0071] Fig. 13CAn implant comprising a non-slanted / non-skewed channel is shown. DETAILED DESCRIPTION

[0072] exist Figure 1 In the invention, the core steps of the printing process of the 3D implant 16 are outlined. In the first step 11, a 3D model 10 of the implant 16 is designed using computer-aided design (CAD) software. At this stage, the 3D model 10 is mainly used to design the external shape of the implant 16 as required (e.g., to adjust to the size of the implant for a specific patient). In the second step 12, the designed 3D model is divided into many layers using filling software. The second step 12 can be regarded as a transition from a theoretical continuous 3D model 10 to a layered definition of the continuous 3D model. These individual layers are so far undefined relative to their internal structure (i.e., the potential filling pattern for the 3D printing of the layer). In the third step 13, a manufacturing input is generated based on the layered 3D model. At this stage, an appropriate filling pattern is selected for each layer of the 3D model 10. The manufacturing input includes a set of machine instructions that can be read by a 3D printer, and the nozzle 15 of the 3D printer can be controlled by the set of machine instructions to print the final implant 16 layer by layer. In the fourth and final step 14, a 3D "real life" object in the form of an implant 16 is manufactured according to the 3D model 10. The 3D implant 16 is manufactured by moving the nozzle 15 of the 3D printer in a coordinated motion according to machine instructions on all three Cartesian axes (X, Y and Z), laying down successive layers of suitable printing materials on the surface until the object is completely built from bottom to top. Typically, individual layers are manufactured parallel to the XY plane. The Z axis is the vertical axis along which the nozzle 15 of the 3D printer moves after completing a layer in order to begin extruding subsequent layers. In the following, the definitions of these three axes will be used below without loss of generality. The actions and three-dimensional motion patterns of the extruder and nozzle 15 used to determine where to extrude the printing material are controlled by a computer numerical control (CNC) programming language (usually G-code in consumer and industrial 3D printers).

[0073] exist Figure 2, a schematic top view of a 3D printed implant (right side) and a separated view of a channel within the implant (left side) are shown. In the top view of the implant 16 on the right side of the figure, it can be seen that the implant 16 includes several channels 21 extending vertically from the base of the implant 16. The channels 21 are arranged in a grid pattern. The channels 21 that are not located at the edge of the implant 16 have a rectangular shape. The channels located at the edge of the implant 16 can have different shapes, such as a triangular shape, because at least one of their walls is a wall for modeling the desired external shape of the implant 16. It is further shown that some channels 21 can have filaments or strips 22 of printed material extending across their cross-sections. The filaments 22 shown as extending across the cross-sections of some channels 21 can, for example, be arranged to model the desired external shape of the implant 16 or be arranged for mechanical stability reasons.

[0074] Figure 2 The left side of the implant 16 shows a schematic channel 21 (marked with a dotted circle), wherein the arrow 30 indicates an extracted enlarged view of the channel 21. The channel 21 is formed by filaments or strips of printed material 22 stacked on top of each other. In this example, the channel 21 has four walls, wherein at any level of the channel 21, the layer contributes two parallel strips 22 to two opposite walls, and the strips 22 have a specific thickness 26 (which can vary throughout the implant 16). Optionally, the filling line can have an average thickness between 80 μm and 250 μm (or, for example, between 100 μm and 200 μm, or, for example, between 150 μm and 180 μm, for example, 170 μm). The length 24 and width 25 of the channel 21 are given by the distance of a pair of adjacent strips 22 of the corresponding layer. However, since the shape of the channel 21 can be arbitrary, and in particular can be defined by external parameters (e.g., stability and / or stiffness), it is not mandatory that the channel has a square (quadratic) or rectangular shape. The channel 21 also includes a top opening 27 and a bottom opening 28. In this example of a uniform (non-tapered) channel 21, the two openings 27, 28 are equal. Arrow 23 indicates the printing direction parallel to the z-axis and perpendicular to the individual layers. Differently, for an implant design with a uniform channel 21 that is not skewed or tilted, the printing direction is consistent with the direction in which the layers are stacked on each other.

[0075] In 3D printing, layers of printed material are stacked on top of each other. Therefore, the easiest and fastest way to create porosity is to print constant channels in the z-direction, i.e. channels with the same cross-section at any level (height) of the channel. Figure 1 and 2 Such an implant configuration is shown in FIG. However, according to various embodiments of the implant provided herein, the architecture is such that the channel of the implant is oriented in a certain direction. Figure 3Detailed description is given in FIG. 3 , which shows different views of an implant, wherein a perspective view is shown in the first row 34, a top view is shown in the second row 35, and a side view is shown in the third row 36. In the left column, a projection form 31 of the implant 16 to be manufactured is shown, for example as planned in the CAD software. The projection form 31 can be designed with respect to aesthetic aspects and mainly describes the external form of the implant 16 to be manufactured. In the middle column, a conventional implant 32 having a form corresponding to the projection form 31 and having a uniform channel 21 is shown. The channel 21 extends vertically from the bottom surface of the implant 16 toward its upper surface. The first arrow 37 shown in the perspective view 34 of the conventional implant 32 indicates the printing direction. However, in the case of a conventional implant, the orientation of the channel 21 described by the second arrow 38 is consistent with the printing direction (therefore, in conventional designs, the first arrow 37 corresponds to the second arrow 38). That is, the first arrow 37 representing the central axis of the channel 21 is consistent with the second arrow 38. As can be seen from the top view 35 , in the conventional implant 32 , the top opening 27 covers the bottom opening 28 of the channel 21 .

[0076] In the right column, an implant 33 according to various embodiments is shown having a form corresponding to the projection form 31. As can be seen from the different views, the channel 21 extends from the bottom surface of the implant 33 to its top surface and is inclined / skewed. In other words, the orientation of the channel 21 represented by the second arrow 38 is not consistent with the printing direction represented by the first arrow 37, so that the first arrow 37 representing the printing direction forms an angle with the second arrow 38 representing the orientation of the channel 21, wherein the angle is different from zero. The orientation of the channel can be selected as required, i.e., according to the preferred position of fat injection and / or according to the mechanical requirements of the implant 16. As can be seen by comparing the conventional implant 32 with the side view 36 of the implant 33 according to various embodiments, when viewed from the top in the direction corresponding to the printing direction (i.e., the first arrow 37), the top opening 27 of the latter does not cover the bottom opening 28 of the channel 21.

[0077] exist Figure 4 The idea behind further advantageous modifications of the implant according to various embodiments is explained in . Figure 4 The arrangement of strips or filaments of printing material 22 forming a channel 21 is shown, which channel 21 is in principle similar to Figure 2 21 shown in FIG. 21 is similar. However, Figure 4 Channel 21 shown in Figure 2 The channel 21 shown in FIG. 1 differs in that it is a tapered channel that, in the exemplary embodiment shown, converges from its bottom opening 28 toward its top opening 27. Each of the four walls formed by each of the other strips 22 of the layer is inclined inwardly, thereby producing the overall tapered form of the channel 21. Figure 4 As shown in , a converging channel (but also a diverging channel) can be characterized by the variation of its cross section along the direction of the orientation of the channel 21 indicated by the first arrow 37. The orientation of a tapered channel can be defined as a line or axis interpolated from the midpoint or center point of the cross section of the channel 21.

[0078] Figure 5 A projected 3D version 31 of an implant is shown on the left and a view of a corresponding implant 52 according to various further embodiments is shown on the right. Figure 3 Similarly, perspective views are shown in the first row 34, top views are shown in the second row 35, and side views are shown in the third row 36. In the left column, the Figure 3 The projected 3D form 31 of the manufactured implant is again used as an example. The implant 52 is similar to Figure 3 implant 33 because its channel 21 is also tilted or oriented in a direction that is inconsistent with the printing direction indicated by the first arrow 37.

[0079] In addition to being inclined, the channel 21 is tapered, i.e., has a Figure 4 Detailed explanation of the form. As can be seen from the different views describing the configuration of the implant 52, the channels 21 extend from the bottom surface of the implant 33 to its top surface, and their top openings 27 are focused toward a predefined area of ​​the top surface of the implant 52 (in this exemplary scenario: the upper right corner). The third arrow 53 represents the focusing direction and can correspond to an axis defined by two points: the middle of the bottom surface / layer of the implant 52 and the intersection of all orientation axes of each channel 21. Instead of the bottom surface / layer, the first point can also correspond to the projection of the center of mass of the implant 52 on the base (i.e., bottom surface / layer) of the implant 52. Alternatively or optionally, the first point can be any point within the bulk volume of the implant. Depending on the desired design, the third arrow 53 can actually point to any direction.

[0080] As mentioned above, Figure 4 The exemplary embodiment of the implant 52 shown in has directional holes / channels that converge toward a predefined area or direction on the upper surface of the implant 52, which facilitates the surgeon's fat injection procedure and allows the patient to have only one scar on the breast. The reason for this is that one of the most commonly used methods of inserting the implant relies on a submammary incision. Since the fat injection will be performed a few weeks after the implant is inserted, according to the implants of various embodiments, the incision used for insertion can also be advantageously used for fat injection. Then, during the injection of fat, the pattern of directional channels 21 can be used as a guide for the surgeon. Since the needle will be aligned with the channel 21, the implant will not be damaged by the needle itself.

[0081] The oriented pores / channels in the implant as a printed porous structure can furthermore advantageously be used to reduce the stiffness of the entire structure in the printing direction. The orientation angle or convergence angle, i.e. the angle between the xy plane (printing plane) and the orientation direction or focus direction, respectively, makes the stiffness tunable. In general, the smaller the convergence angle, the softer the structure. This concept is discussed in detail in detail in the literature. Figure 6 , which shows a first implant 61 with a tapered channel and a second implant 62 with a uniform channel, both of which have inclined channels. As in the previous case, the first arrow 37 represents the printing direction for the exemplary implants 61, 62, and the third arrow 53 displayed on the first implant 61 indicates the focusing direction of each channel. As can be derived from the orientation of the third arrow 53, the channel is focused toward the top center of the implant 61. In the second implant 62, the third channel 53 is oriented toward the right side of the implant 62. Since the convergence angle of the second implant 61 is much smaller than the convergence angle of the second channel (which is close to 90 °), the lateral displacement from one layer to the next layer and therefore the lateral displacement from one filament to the next filament are larger in the second implant 62. Therefore, the filaments in the second implant 62 are not directly arranged on top of each other. Compared with the first implant 61, this macro effect leads to a softer second implant 62.

[0082] As described above, implants according to various embodiments are manufactured by sequential printing of layers. Figure 7 , an exemplary first layer 71 and an exemplary second layer 72 are shown. During the manufacturing of the layers 71, 72 by 3D printing, each layer is printed in the form of a line of printed material between a starting point 74 and an end point 75 according to a predefined fill pattern 76, 77. As shown, the first layer 71 includes a first fill pattern 76, and the second layer 72 includes a second fill pattern 77, and both fill patterns 76, 77 have a zigzag shape. The starting point 74 and the end point 75 are not necessarily visible in the final product, and are not necessarily visible in the final product. Figure 7The schematic diagram shown is exaggerated for ease of understanding. The perimeter 78 of each layer 71, 72 is determined by the slice (slice) of the projection 3D model of the implant. That is, each filling pattern 76 is defined by the perimeter 78, so that when the layers manufactured during the printing process are stacked on top of each other, the final 3D product has a 3D form closely similar to the projected 3D model. The part of the filling pattern at the perimeter 78 of the corresponding layer is printed so that they track the perimeter 78. The inside of the layer 71, 72 can be filled with a filling pattern of any shape that can be selected according to the boundary conditions (hardness, porosity, density). After the 3D printer has extruded the filling pattern of the first layer 71, the nozzle stops at the end point 75 of the first layer 71, the distance between the nozzle and the printing plane is changed (usually by moving the nozzle upward in the direction indicated by the arrow 73), and the filling layer of the second layer 72 is formed, which starts at the starting point 74 of the second layer 72.

[0083] After the second layer 72 has been printed on top of the first layer 71, the third layer is deposited on the second layer. Figure 7 ) can be similar to the first layer. Figure 7 As shown, the material lines of the first filling pattern 76 that are not arranged on the perimeter 78 of the first layer 71 are arranged at an angle to the material lines of the second filling pattern 77 that are not arranged on the perimeter 78 of the second layer. This arrangement produces a channel located in the final implant. Directed channels and / or inclined channels are formed by gradually shifting the internal structure of the filling patterns 76, 77 in the desired direction. For example, it can be made by manufacturing Figure 7 and then shifting the straight strips of the third filling layer to the right relative to the first filling layer 76 to form a strip directed to Figure 7 The right channel makes it possible to Figure 7 When viewed from the top at the angle shown, the bars of the third layer's fill pattern are offset to the right relative to the bars of the first fill pattern. Continuing the process for another odd-numbered layer results in Figure 3 The implants shown in the right column. Figure 4 As shown, a tapered channel can be formed by arranging lines of printed material in a fill pattern.

[0084] A method for generating a printing path for a 3D printer for printing a porous object including a channel extending through the porous object, such as a 3D implant described herein, is further provided. The channel of the porous object is formed by holes included in the layers printed during the manufacture of the porous object. The generated printing path includes a set of path points along which a printing nozzle of the 3D printer moves so as to print the material layers one by one to ultimately manufacture the 3D implant.

[0085] In a first step, a method for generating a printing path according to various embodiments comprises decomposing a 3D model of a porous object (3D object) into a set of layers, each layer comprising a contour of the 3D model at a corresponding height of the 3D model, the height being aligned with the printing direction. Thus, the first step may comprise filling the 3D model into slices, each slice representing a printed layer. During printing, each layer is manufactured by extruding a printing material from a nozzle of a printer along the printing path. Typically, the respective planes are parallel to a printing surface on which the 3D object is printed, the 3D object being assumed to correspond to an xy plane. The layers are manufactured by extruding the printing material on top of each other in a printing direction assumed to correspond to the z direction. The overall extrusion of the layers typically occurs in a cross-shaped pattern, such that the filaments of one layer are extruded onto the filaments of the previous layer at an angle (most typically 90°). The purpose of this first step of the method, corresponding to the design / planning phase, is to generate layers, each layer comprising a contour of the 3D model at a corresponding height of the 3D model. The structure of the interior of each layer is a design parameter and can be selected later according to the needs of the respective application.

[0086] In another step, the method includes intersecting one or more layers of a set of layers with a set of fill lines, wherein the distance between the fill lines for each layer is set to correspond to the size of the holes in the layer in a direction perpendicular to the fill lines. By intersecting the layer with the set of fill lines, the layer is divided into strips, wherein two opposing sides simply correspond to portions of two adjacent fill lines, and the other two opposing sides represent portions of the outline of the layer. The fill lines preferably correspond to representations of portions of material extruded during the printing process. The two opposing sides representing portions of the outline of the layer can be approximated by straight lines during the printing process, wherein the straight lines extend between corresponding edges of the strip. In some embodiments, the fill lines can be equidistant, thus resulting in uniformly sized holes within the layer.

[0087] In another step of the method, a printing path is formed for one or more layers (which have been pre-sliced ​​in the previous step) based on the intersections between the set of fill lines and the contours of the corresponding layers. In this sense, the fill lines can also be called search lines, because they are used to search for their intersections with the contours of the layers. Preferably, the printing path for a given layer can consist of intersections arranged in such a sequence that, during printing of the 3D object, the nozzle will move along the printing path in a zigzag manner from one intersection to the next intersection and continuously extrude the printing material from the starting point of the layer to the end point of the layer. It should be noted that, for example, Figure 7 As shown in , although the corresponding layer basically includes an outline and the calculated intersection points are all located on the outline of the layer, the material layer of the 3D object extruded based on the calculated intersection points may include an intermittent representation of the outline of the layer and a fill including straight lines of printed material (which corresponds to the fill lines). Figure 7 In contrast to the layers shown in , intermittently represented portions of the contour of a layer may also be approximated by straight lines rather than curved or arcuate lines in order to simplify the printing path of a 3D printer nozzle which typically moves in a straight line.

[0088] In another step of the method, the previous two steps (i.e., filling the layer and forming the printing path) are performed with respect to one or more layers located above those layers processed so far (previously) and using the set of filling lines for this purpose, the set of filling lines being arranged at an angle (preferably at 90°) to the set of filling lines that have been used for the layers processed so far (previously). The division of the layers of the 3D object into two batches of layers reflects the cross-sectional nature of the printing process. Note that the cross-sectional pattern is formed by repeatedly depositing one or more (a) filling lines in a first direction and then depositing one or more (b) filling lines in another direction, wherein the other direction is oriented at an angle of preferably 90° to the first direction, and then by repeating this process at least once, preferably multiple times. In this way, by adjusting the number of layers in each batch, the height of the walls of the holes can be changed from one layer to the next. In the special case of a=b, the cross-sectional pattern is formed by a filling pattern of the 3D model, wherein every other filling line is oriented in the first direction, wherein individual filling lines are arranged between and oriented in a second direction different from the first direction (e.g., see Figure 7 ). In the case where the second direction is 90° to the first direction, each channel has a square cross-section when viewed parallel to the printing direction. For example, the first batch of layers may include layers with an odd number of 3D objects, starting with the first layer (bottom layer) of the 3D objects. For the first batch of layers, the fill line may be parallel to the x-axis of a coordinate system in which the 3D model of the 3D object to be printed is processed / represented. The second batch of layers may include layers with an even number of 3D objects, starting with the second layer of the 3D objects. In the case of rectangular holes, the fill lines used to fill the layers in the second batch of layers may be parallel to the y-axis of the coordinate system in which the 3D model of the 3D object to be printed is processed / represented. In the case of tapered channels, the fill lines ... Figure 4 , 5 and 6) or diverge, with the distance between fill lines becoming smaller or larger from one layer to the next.

[0089] According to a further embodiment of the method, in the case of a constant channel (see, for example, Figure 3 ), the distance between lines can be the same for all layers.

[0090] According to a further embodiment of the method, a first line in a set of lines for a layer in a batch of layers may be laterally offset relative to a first line in a set of lines for an adjacent layer. This may also be the case for all other lines in the set for adjacent layers. The position of the first fill line in the respective layer may correspond to an intersection line between a boundary plane of the 3D model and a plane in which the layer is embedded. The 3D model may be defined by three boundary planes, one of which may correspond to a plane in which the bottom layer of the 3D model is embedded. For example, the cross-sectional shape of a confining area of ​​the 3D model may be triangular when viewed in an xz plane in a 3D model representation coordinate system.

[0091] According to another embodiment, the method may also include a step for determining a restricted area for a 3D model. Therefore, the method may also include intersecting the representation of the 3D model of the porous object with a plane to form a work plane and performing subsequent steps in the work plane. For example, without loss of generality, the work plane may correspond to the xz plane in the 3D model representation coordinate system, wherein the origin of the coordinate system is located at the projection of the mass center of the 3D model at the bottom surface or the center of the bottom layer of the 3D model. The method may also include specifying the hole size of the first hole in the layer at a first height, preferably at the base (bottom surface) of the 3D model represented by the first line segment (located in the work plane). The method may also include specifying the hole size of the second hole in the (different) layer of the porous object at the second height of the 3D model represented by the second line segment (which is also located in the work plane), the first hole and the second hole belonging to the same channel. The hole size of the first hole and the second hole may correspond to the distance between the lines used to fill the corresponding layers. The method may also include calculating the first orientation line by connecting the left endpoints of the first and second line segments, and calculating the second orientation line by connecting the right endpoints of the first and second line segments. The method may further include calculating the intersection of the first orientation line and the second orientation line. The intersection corresponds to the convergence point of the wall associated with the corresponding hole in the case of a non-constant channel (i.e., a divergent or convergent channel). The convergence point is located above the xy plane for the convergent channel or below the xy plane for the divergent channel, wherein the base or bottom surface layer of the 3D model is embedded in the xy plane. The method may also include selecting a main orientation line corresponding to one of the first orientation line and the second orientation line, which has a smaller distance to the center of the base of the 3D model or to the projection of the center of mass on the base of the 3D model. The method may also include changing the slope of the main orientation line to determine the first boundary line and the second boundary line, both of which run through the intersection (convergence point) and are tangent to the 3D model. The first boundary line and the second boundary line can both be extended to the corresponding boundary plane (tangent plane), which is arranged at an angle (e.g., vertically) to the xz plane. Finally, the method may include limiting the area, wherein the intersection between the outline of the layer and a set of fill lines is determined as the area defined by the intersection between the plane including the corresponding layer and the first and second tangent planes.

[0092] In the following, exemplary embodiments of the method will be described. Figure 8 In FIG. 8 , a 3D model 81 is shown in a modeling space 80. In this example, the 3D object 81 is modeled by a hemisphere. In general, the 3D model O={G} consists of a set of geometric functions G. The modeling space 80 includes a 3D model representation coordinate system, whose origin 84 is located at the center of the bottom layer or at a point corresponding to the projection of the center of mass of the 3D object 81 on its base. The base or bottom surface of the 3D model 81 is located in the xy plane (defined by the x-axis and y-axis of the coordinate system), which is not in the Figure 8It is clearly shown in the figure. It shows the direction vector (also with reference number 85), which represents the tilt / skew direction of the channel and is a parameter that can be provided by the user. The bottom-up assembly method of 3D printing mainly considers vertical and horizontal deposition along the x-axis and y-axis in the xy plane of the coordinate system. Therefore, the direction vector is projected onto the xz plane 82 (defined by the x-axis and z-axis of the coordinate system) and onto the yz plane 83 (defined by the y-axis and z-axis of the coordinate system) of the coordinate system, so that the two resulting direction vectors (also with reference number 86) and (also with reference number 87) are the projection direction vectors for vertical and horizontal deposited channels, respectively. The following description will focus on the manufacture of layers where the internal support comprises strands of printed material extruded parallel to the y-axis. The same process can be used for a plane comprising a path of extruded material arranged along the x-axis.

[0093] In addition to the external shape of the 3D model 81, the channel direction vector In addition to the user-defined geometry information {G}, this method can receive the following input parameters from the user:

[0094] D n : The diameter of the nozzle of the 3D printer,

[0095] LT: layer thickness, i.e., the thickness of the strand of material deposited by the nozzle, where the boundary condition LT <D n ,

[0096] Pore b : The hole size at the base of the 3D model 81,

[0097] Pore u : At a user-defined height h u The hole size at

[0098] h u : User defined height at which the hole size Pore is specified u .

[0099] At least a subset of the user defined parameters may be used to calculate the convergence point of the walls of the channel defining the 3D model 81. This will be based on Fig.9A and 9B To explain, Fig.9A and 9B The following table shows the Figure 8 A scene of converging and diverging channels in the xz plane of the coordinate system of the . Based on the input data, an algorithm is used to determine whether the channels are converging or diverging. bIt is represented by a first line segment 91, one of whose endpoints corresponds to the origin 84 of the coordinate system. u It is represented by a second line segment 93 at a user-defined height 92. The overall height of the 3D model 81 corresponds to the second height 94. b and Pore u The same channel of the 3D model 81 may be involved, wherein the position of the second line segment 93 relative to the first line segment 91 in the xz plane 82 may be derived from the direction vector 85. In general, a linear correlation exists between the hole size Pore of the corresponding hole u With height h u The convergence point 97 of the channel (or its wall) is determined by connecting the left endpoints of the first line segment 91 and the second line segment 93 to calculate the first orientation line 96 and by connecting the right endpoints of the first line segment 91 and the second line segment 93 to calculate the second orientation line 95. Fig.9A and 9B As shown, direction vector 85 lies on second orientation line 95. First orientation line 96 and second orientation line 95 correspond to a one-dimensional representation of the wall of the channel. By calculating the intersection of first orientation line 96 and second orientation line 95, a convergence point 97 of the wall is obtained. Depending on the position of convergence point 97 relative to 3D model 81, i.e., whether convergence point 97 is located above 3D model 81 and therefore above xy plane, as Fig.9A , or below the 3D model 81 and therefore below the xy plane, as shown in Fig. 9B As shown, the algorithm can determine whether the channel is converging or diverging. It should be noted that in the case of a constant channel, the first and second line segments 96, 95 are parallel, and the direction vector 85 corresponds to the second arrow 38 representing the orientation of the constant channel (see Figure 3 ).

[0100] After the properties of the channel have been determined, Fig.10 The 3D model 81 of the porous object shown in is decomposed into a set of layers 101, each layer comprising the contour of the 3D model at a corresponding height of the 3D model. In the example of the 3D model 81 in the form of a hemisphere, each layer 101 corresponds to a disk arranged parallel to the xy plane of the coordinate system, and each layer can be extruded by a purely two-dimensional movement of the nozzle during printing.

[0101] exist Fig.11 In the next step shown, a printing path is determined for each layer 101. This is done by making each layer 101 intersect a set of fill lines 102, where the distance 103 between the fill lines 102 for each layer 101 is set to correspond to the size of the hole in that layer 101 in a direction perpendicular to the fill lines. For example, for a hole at a user-defined height h u The layer at Fig.9A and Fig. 9B ), the distance 103 between the fill lines 102 will correspond to the aperture Pore u The printing path is determined based on the intersections 104 between the set of fill lines 102 and the outline of the layer 101. The sections of the printing path 105 are Fig.11 The print path is formed by an ordered group of intersections 104, wherein the intersections 104 are arranged as indicated by arrows forming a print path 105 (i.e., lower intersection 104 of the nth fill line -> upper intersection 104 of the nth fill line -> upper intersection 104 of the (n+1)th fill line -> lower intersection 104 of the (n+1)th fill line).

[0102] In more detail, the 3D object 81 is presented as a group of S layers 101, {L S} S＝1,…,S , and in h s Each layer at the corresponding height L S Contains geometric information G, mainly the shape of the layer's outline (circular, elliptical, etc.). Each layer L S Groups that can be defined as contours q=1,…,Q. Each contour is a closed curve, which represents the 3D model 81 in the corresponding layer L S The deposition of printed material above layer s is preferably done by parallel fill lines a=1,…,A represents. As already mentioned, the fill line The distance between them is set to correspond to the s The size of the holes in the corresponding layer at the first line The starting position of the 3D printing path plan can be defined by the intersection of the tangent plane and the plane in which the corresponding layer is embedded. This aspect will be explained in more detail later. As already explained, the ordered set of points is generated from the path plan for 3D printing by arranging the intersection points 104 in an ordered manner. These points The printing path that the nozzle of a 3D printer follows during 3D printing.

[0103] In the case of a non-constant channel (i.e., a converging or diverging channel), the size of the holes varies gradually from one layer to the next. At the same time, also in the case of a constant channel, the number of holes for all layers L S are equal.

[0104] The number of fill lines 102 should be as small as possible in order to reduce the required calculation time. To do this, the relevant area in which the fill lines 102 are arranged can be limited, for example, by calculating two boundary planes. Fig. 12A and 12BThe computation of the boundary surface is explained in Fig. 12A shows the scenario for a divergent channel, Fig. 12B The scenario for a constant channel is shown. The calculation is based on Figure 8 81 . First, the rotation axis 121 is calculated by extending the point of the convergence point 97 to a line parallel to the xy plane 120 or preferably in the xy plane 120. In a similar manner, a direction plane 122 can be formed based on the direction vector 85, wherein the direction plane 122 is perpendicular to the xz plane 82. By changing the slope of the second orientation line 95 (i.e., the extension of the direction vector 85) while keeping the second orientation line 95 anchored at the convergence point 97, a first boundary line with a negative slope and a second boundary line with a positive slope (both of which are tangent to the 3D model 81) can be determined. The tilt / rotation of the second orientation line 95 around the convergence point 97 corresponds to the tilt / rotation 121 of the direction plane 122 around the rotation axis 121. The corresponding first boundary plane 123 and the second boundary plane 124 can be determined by extending the first boundary line and the second boundary line into a plane perpendicular to the xz plane 82. Both boundary planes 123 and 124 are tangent to the 3D model 81. The boundary planes 123, 124 are then used to limit the area in which the intersection point 104 is determined. The area may be defined by the intersection lines between the plane including the respective layer 101 and the first and second tangential planes 123, 124. Any of these intersection lines may be used as the first fill line for a given plane 101. First fill line for other layers 101 The intersection line for the bottom layer of the 3D model 81 may correspond to the intersection line between the plane of the corresponding layer 101 and the same of the first and second tangentially defined planes 123, 124. Fig. 12A is shown as being perpendicular to the xz plane 82 and running through the first boundary point 125 (X min ) and the second boundary point 126 (X max The first boundary point 125 and the second boundary point 126 correspond to intersections between the xy plane 120 and the first boundary line and the second boundary line.

[0105] The scenario for the converging channels is similar to Fig. 12A, the main difference being that the rotation axis 121 is not arranged below the xy plane 120, but above the xy plane 120. Therefore, the slopes of the first and second boundary planes 123, 124 are inversely proportional, i.e. the slope of the first boundary plane 123 is positive and the slope of the second boundary plane 124 is negative. In the case of a constant channel, in the absence of a concentration point 97 due to the direction vector 85 describing the orientation of the channel, the first boundary line and the second boundary line are parallel, and the first boundary line and the second boundary line (and the corresponding first and second boundary planes 123, 124) are obtained by translating the second orientation line 95 until it becomes tangent to the 3D model 81.

[0106] The pore size Pore at any sth layer 101 can be defined by first calculating the number of pores N in the first layer (bottom layer) s :

[0107] N=(X max -X min ) / Pore b

[0108] Then, by using the calculated number of holes N, which for consistency reasons remains constant for all layers of the 3D model, the hole size Pore at the sth layer can be determined. s :

[0109] Pore s =(X max -X min ) S / N

[0110] Fig.13A A cross-sectional side view of an implant 1330 for insertion into a patient is shown in accordance with various embodiments.

[0111] Implant 1330 includes layers 101 of three-dimensional (3D) printed structures. Each layer 101 includes a fill pattern of the 3D printed structure (e.g., a combination of Figure 7 The implant 1330 further comprises a plurality of hollow channels 21. The layers 101 are arranged on top of each other so that a plurality of hollow channels 21 are formed within the implant 1330. The walls 134 of each channel 21 are formed by segments of the fill lines of the plurality of layers in the printed layer structure. At least one hollow channel (21) extends between a first outer surface 138 of the implant and a second outer surface 139 of the implant. At least one hollow channel (21) is oriented in a direction (53) that is inclined relative to a reference axis 137 that is perpendicular to the first outer surface of the implant.

[0112] The first outer surface 138 of the implant can be the maximum plane (flat) surface of the implant. For example, the first outer surface 138 can be the flattest surface of the implant and / or the surface with the minimum curvature amount. The first outer surface 138 can be a bottom surface, which can be the surface of the implant facing or closest to the chest wall of the patient after insertion. The first outer surface of the implant can be parallel to the two-dimensional (xy) plane formed by the first layer (or one or more layers) of the three-dimensional (3D) printed structure. Fig.13A The cross-sectional side view of can be from a cross section perpendicular to the first exterior surface 138 (ie, perpendicular to the xy plane).

[0113] In addition, or alternatively, the second outer surface 139 can be a non-coincident (e.g., non-intersecting) surface to the first outer surface 138. The second outer surface 139 can be a side surface of the implant or a top surface of the implant. Alternatively, the first outer surface 138 and the second outer surface 139 of the implant can be relatively facing surfaces. For example, the first outer surface of the implant can be a bottom surface and the second outer surface can be a top surface. Optionally, the second outer surface 139 can be a curved surface of the implant. The channel 21 (or a protrusion or extension of the channel 21) can terminate at the second outer surface 139, defining an intersection between the channel 21 and the second outer surface 139. The tangential plane at the intersection between the channel 21 and the second outer surface 139 may not be parallel to the xy plane.

[0114] The tilt-reference angle α can be defined as the angle between the reference axis 137 and the central longitudinal axis 141 of the channel 21. The reference axis 137 can be perpendicular to the xy plane of the layer (e.g., perpendicular to most layers, such as perpendicular to more than 50% of the layers). For example, the reference axis 137 can be parallel to the z-axis. For example, the reference axis 137 can be perpendicular to the plane formed by the first outer surface 138 of the implant. In a cross-sectional side view of the implant 1330, the tilt-reference angle α can be between 10 degrees and 85 degrees (or, for example, between 45 degrees and 85 degrees), and the cross-sectional side view is perpendicular to the xy plane.

[0115] The central longitudinal axis 141 of the channel 21 may be a central longitudinal axis of symmetry, which may be a straight line located at the midpoint of the fill line of the walls 134 forming the channel 21. Alternatively, in the case of a non-tapered channel, the central longitudinal axis 141 may be parallel to each of the walls 134 of the channel 21.

[0116] At least one hollow channel 21 (e.g., one or more hollow channels 21) extends between the first outer surface 138 of the implant and the second outer surface 139 of the implant. Optionally, more than 30% (or, for example, more than 50%, or, for example, more than 80%, or, for example, each) of the hollow channels 21 extends between the first outer surface 138 and the second outer surface 139. "Extending between the first outer surface 138 and the second outer surface 139" can be understood to include examples even if the channel 21 does not terminate directly at the surface. For example, "extending between the first outer surface 138 and the second outer surface 139" may include examples in which the channel 21 terminates (one or more layers) before reaching the first outer surface 138 and the second outer surface 139, in other words, the opening of the channel 21 is not necessarily formed at the outermost layer of the implant. In some examples, it is possible that the channel 21 includes a deflected (inclined) portion and at least one non-inclined portion. The non-inclined portion of the channel 21 can be a portion parallel to the reference axis (e.g., the inclination-reference angle is zero). For example, the (first) non-inclined portion may have an opening at the first outer surface of the implant. The inclined portion of the passage 21 may be located between the first non-inclined portion and an optional second non-inclined portion having an opening at the second outer surface of the implant. The non-inclined portion of the passage 21 may be formed by one or more (e.g., a plurality of) of the outermost layers of the implant at the first outer surface of the implant or the second outer surface of the implant.

[0117] "Extending between the first outer surface 138 and the second outer surface 139" may also include examples in which at least one end of the channel terminates at the outermost layer of the implant. For example, the channel 21 may extend completely from the first outer surface 138 to the second outer surface 139. For example, the channel 21 originates from the first outer surface 138 and terminates at the second outer surface 139. It is further understood that not all hollow channels 21 originate from the first outer surface 138 and terminate at the second outer surface 139. For example, it is possible that some of the channels 21 located on one side of the implant (or the extrapolation of the channels) do not originate from the first outer surface 138.

[0118] At least 10% (or for example at least 20% or for example at least 30% or for example at least 50% or for example all) of the hollow channels in a plurality of hollow channels can tilt the same tilt-reference angle relative to the reference axis. The hollow channels with the same tilt-reference angle can be aligned in the same direction, and the size of the tilt-reference angle can be the same. Alternatively or optionally, more than two hollow channels (or for example, more than 3 hollow channels or more than 5 hollow channels) can tilt the same tilt-reference angle relative to the reference axis. In the case of a tilted constant channel, the tilt-reference angle can be the same for each channel. In other words, all hollow channels in the implant can be parallel to each other, ignoring the deviation caused by manufacturing defects.

[0119] Optionally, at least one hollow channel (or, for example, one or more or all of the hollow channels) can be a tapered channel. Optionally, multiple hollow channels can converge toward a predefined area at a first outer surface of the implant or at a second outer surface. In some embodiments, the predefined area can be a convergence point directly on the first outer surface of the implant or directly on the second outer surface. Alternatively, the predefined area can be a convergence point located outside (outside) the first outer surface of the implant or outside (outside) the second outer surface. In other words, the convergence point can be located outside the implant (e.g., in combination with Fig.9A and 9B described).

[0120] Fig. 13B A cross-sectional side view illustration of an implant 1330 including an inclined / skewed hollow channel is shown in accordance with various embodiments.

[0121] The layers of a three-dimensional (3D) printed structure may include a first batch of layers and a second batch of layers. The first batch of layers may include odd-numbered layers in the layers of the three-dimensional (3D) printed structure, and the second batch of layers may include even-numbered layers in the layers of the three-dimensional (3D) printed structure.

[0122] The fill lines of the first batch of layers may be oriented in a first direction and the fill lines of the second batch of layers may be oriented in a second direction different from the first direction. Portions of the fill pattern of the odd-numbered layers in the first batch of layers may be displaced relative to portions of the fill pattern of the first fill layer in the first batch of layers. Additionally or alternatively, portions of the fill pattern of the even-numbered layers in the second batch of layers may be displaced relative to portions of the fill pattern of the first fill layer in the second batch of layers.

[0123] Each odd-numbered layer of the plurality of layers of the 3D printed structure may include a first fill line 102 y1 and the second filling line 102 y2 , first filling line 102 y1 and the second filling line 102 y2The first fill line 102 may be parallel to and directly adjacent to the odd-numbered layers. y1 For example, odd-numbered layers may refer to layer 1, layer 3, layer 5, etc., or generally represented by the formula layer n+2*(t), where t is an integer greater than or equal to 0. For example, t may be, but is not limited to, an integer between 30 and 200. Fig.13A As shown, any first odd-numbered layer (layer 1) may be a layer where n = 1, and t = 0. The first odd-numbered layer may be, but is not limited to, the outermost layer at the first outer surface of the implant.

[0124] The lateral pore size (pore1) may be the first fill line 102 of the first odd numbered layer (layer 1) 11 The second adjacent (immediately following) fill line 102 of the first odd-numbered layer 12 The distance 103 can be between the first filling line 102 of the first odd-numbered layer. 11 The central longitudinal axis 131 and / or the second fill line 102 of the first odd-numbered layer 12 The first fill line 102 of the first odd-numbered layer is measured in a direction perpendicular to the central longitudinal axis 132 (x direction). 11 The central longitudinal axis 131 may be aligned with the first fill line 102 of the first odd-numbered layer. 11 The second fill line 102 of the first odd-numbered layer is parallel to the axis of length (eg, parallel to the y-axis). 12 The central longitudinal axis 132 may be aligned with the second fill line 102 of the first odd-numbered layer. 12 The length is parallel to the axis.

[0125] The lateral offset value ov may be defined as the distance between the central longitudinal axis 131 of the first fill line of the first odd-numbered layer and the first fill line 102 of the second odd-numbered layer (eg, layer n+2=3). 31 The minimum distance between the central longitudinal axis 133 of the second odd-numbered layer. 31 The central longitudinal axis 133 may be aligned with the first fill line 102 of the second odd-numbered layer. 31 The lateral offset value ov may be measured in a horizontal direction parallel to the layer (eg, parallel to the x-axis).

[0126] The lateral offset value ov may be greater than zero and less than 50% (or for example less than 30%, or for example less than 10%, or for example less than 5%, or for example less than 1%) of the pore size of the first pore of the first layer (layer 1), 103 (or pore1), ignoring deviations due to manufacturing defects.

[0127] The filling lines 102 of the odd-numbered layers of the channel 21 can be arranged such that the filling lines 102 of the odd-numbered layer (e.g., layer 1) that form part of the wall 1341 of the hollow channel 21 11 of the part can be offset by a lateral offset value ov with respect to the closest (nearest) parallel filling line 102 in an adjacent odd-numbered layer (e.g., layer 3) that forms the same part of the same wall 1341 of the same hollow channel 21 31 By way of example, the part of the filling line of the n + 2*(1) layer can be offset by the lateral offset value ov with respect to the closest (or nearest) parallel filling line in the n layer. The subsequent odd-numbered layer n + 2*(2) can be offset by the same lateral offset value with respect to the closest parallel filling line in the n + 2*(1) layer. In the case of a constant channel, the lateral offset value can be constant (or the same) for more than 80% of the layers in the implant, ignoring the deviations caused by manufacturing.

[0128] All parts of the filling lines of the same wall of the same hollow channel can have a cumulative (summed) lateral offset value with respect to the filling line of the first layer that forms the wall. In the case of a constant inclined channel, the cumulative lateral offset value can be a multiple of the lateral offset value between adjacent odd-numbered layers. For example, the first filling line in the n + 2*(t) layer of the wall 1341 can have a cumulative lateral offset value of ((t - 1)*ov) with respect to the first filling line 102 in the first layer of the wall 1341 11 ((t - 1)*ov). Only for integer values greater than 2, i.e., for odd-numbered layers 7, 9 and onwards, the filling lines can be arranged such that the cumulative lateral offset value of ((t - 1)*ov) can be greater than or equal to the pore size 103 (or pore1) of the first pore of the first layer. In this case, t can be, but is not limited to, values such as 2 < t < 8 or for example 4 < t < 20. In other words, for t values less than or equal to 2, the cumulative lateral offset value ((t - 1)*ov) can be less than the pore size 103 (or pore1), ignoring the deviations caused by manufacturing. Alternatively or optionally, in the case where the tilt-reference angle is very small (e.g., less than 5 degrees), even for integer values of t greater than 2, the cumulative lateral offset value of ((t - 1)*ov) can be less than the pore size 103.

[0129] The wall 1341 of the inclined channel 21 that extends between the top surface and the bottom surface of the implant can be composed of parts of the filling lines 102 from each odd-numbered layer. The wall 1341 can be formed by the filling lines of multiple odd-numbered layers in the channel 21 such that the filling lines 102 11 of the part and the closest (nearest) parallel filling lines 102 of adjacent (or consecutive) odd-numbered layers (e.g., layer 3) 31The portions of the same hollow passage 21 form portions of the same wall 1341. Similarly, the parallel fill lines 102 of the adjacent (or immediately following) odd-numbered layers (e.g., layer 5) 51 The parts form parts of the same wall 1341 of the same hollow channel 21.

[0130] Any wall of the hollow channel may be formed by the segmentation of every other layer in the arrangement of the layers forming the implant. The first wall 1341 of the hollow channel 21 may be formed by the portion of the first fill line of the odd-numbered layer. The second wall 1342 of the hollow channel 21 may be formed by the portion of the second fill line of the odd-numbered layer. The second wall 1342 may also be the wall of the second adjacent (directly adjacent) hollow channel, which may be parallel to the first hollow channel in the case of an inclined constant channel.

[0131] Each even-numbered layer (e.g., layers 2, 4, 6, ... 2*t) in the plurality of layers of the 3D printed structure may include a first fill line and a second fill line, and the first fill line and the second fill line may be parallel to the first fill line of the directly adjacent even-numbered layer. The third wall of the hollow channel 21 may be formed by a portion of the first fill line of the even-numbered layer. The fourth wall of the hollow channel 21 may be formed by a portion of the second fill line of the even-numbered layer in the plurality of layers.

[0132] In some other examples, the first fill line 102 of the first odd-numbered layer 11 The first fill line with the second odd numbered layer 102 31 The lateral offset value between the first fill line 102 of the first odd-numbered layer 11 The second adjacent fill line 102 of the first odd-numbered layer 12 For values ​​of t greater than or equal to 2, the first fill line 102 of an odd-numbered layer (e.g., layer n+2*t) is aligned with the first fill line 102 of the first odd-numbered layer. 11 The cumulative lateral offset value between the first odd-numbered layer and the first fill line 102 may be greater than 11 The second adjacent fill line 102 of the first odd-numbered layer 12 The distance between.

[0133] It is understood that the terms "odd-numbered layer" and "even-numbered layer" may refer to a single (i.e., one) layer, or they may also refer to "a group of odd-numbered layers" and "a group of even-numbered layers," respectively. In other words, the term "odd-numbered layer" may refer to one or more layers within a group of odd-numbered layers. Similarly, the term "even-numbered layer" may refer to one or more layers within a group of even-numbered layers.

[0134] Understandably, combined Figures 1 to 12BThe features of the implant described in the embodiments (layers of 3D printed structures, fill patterns, fill lines, multiple hollow channels, walls of channels, odd-numbered layers, even-numbered layers) can also be applied to Fig.13A and 13B implants.

[0135] Fig. 13C An example of a channel that is not tilted relative to the printing direction is shown. Fig. 13C As shown, the lateral offset value is zero.

[0136] Those skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned as well as those inherent therein. Furthermore, it will be apparent to those skilled in the art that various substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. The compositions, methods, processes, treatments and specific compounds described herein presently represent certain embodiments and are therefore exemplary and are not intended as limitations on the scope of the invention. Those skilled in the art will recognize variations and other uses encompassed within the spirit of the invention, which is defined by the scope of the claims. In this specification, a listing or discussion of previously disclosed documents is not necessarily considered an acknowledgement that the document is part of the art or is common general knowledge.

[0137] The present invention described illustratively herein may be practiced appropriately in the absence of any element or elements, restrictions or limitations not specifically disclosed herein. Thus, for example, the terms "include", "comprise", "contain", etc. should be read broadly and non-restrictively. In addition, the terms and expressions used herein have been used as terms of description rather than limitation, and it is not intended that any equivalent or part thereof of the features shown and described be excluded using these terms and expressions, but it should be recognized that various modifications are possible within the scope of the claimed invention. Therefore, it should be understood that although the present invention has been specifically disclosed by exemplary embodiments and optional features, and modifications and variations of the present invention embodied herein may be adopted by those skilled in the art, and these modifications and variations are considered to be within the scope of the present invention.

[0138] The invention is described broadly and generically herein. Each of the narrower species and sub-generic groupings falling within the generic disclosure also form a part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether the excised material is specifically recited herein.

[0139] Other embodiments are within the following claims.In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.

Claims

1. An implant (16, 33, 52, 61, 62) for insertion into a patient, wherein: The implant comprises: Layers (71, 72, 101) of a three-dimensional (3D) printed structure, wherein each layer (71, 72) comprises a fill pattern (76, 77) of the three-dimensional printed structure, the fill pattern (76, 77) of each layer comprising a set of fill lines, wherein the layers are arranged on top of each other such that a plurality of hollow channels (21) comprising walls are formed within the implant, wherein adjacent hollow channels among the plurality of hollow channels (21) are separated from each other by the wall, wherein a wall of a first hollow channel is a wall of a second adjacent hollow channel, and wherein each hollow channel comprises a skewed wall, wherein the skewed wall is formed by segments of the fill line of a plurality of alternating layers in the layers of the printed structure, wherein the segments of the fill line are oriented in a first direction and are arranged above each other with a lateral offset, wherein the lateral offset is a dimension in a direction parallel to the first outer surface of the implant, wherein the lateral offset is greater than zero and less than 50% of a lateral channel dimension, wherein at least one of the plurality of hollow channels (21) extends between a first outer surface of the implant and a second outer surface of the implant, Wherein the at least one hollow channel is oriented in a direction (53) that is inclined relative to a reference axis that is perpendicular to the first outer surface of the implant.

2. The implant according to claim 1, wherein The first outer surface and the second outer surface of the implant are oppositely facing surfaces.

3. The implant according to claim 1, wherein The first outer surface is parallel to a two-dimensional plane formed by a first layer of the three-dimensional (3D) printed structure.

4. The implant according to claim 1, wherein The first outer surface is the largest planar surface of the implant.

5. The implant according to claim 1, wherein The angle between the longitudinal axis of the at least one hollow channel and the reference axis is between 10 degrees and 85 degrees.

6. The implant according to claim 1, wherein The layers (71, 72, 101) of the three-dimensional (3D) printed structure include a first batch of layers and a second batch of layers, wherein the first batch of layers comprises odd-numbered layers of the layers of the three-dimensional (3D) printed structure, and wherein the second batch of layers comprises even-numbered layers among the layers of the three-dimensional (3D) printed structure, wherein the fill lines of the first batch of layers are oriented in a first direction, and wherein the fill lines of the second batch of layers are oriented in a second direction different from the first direction, wherein portions of the fill pattern of the odd-numbered layers in the first batch of layers are displaced relative to portions of the fill pattern of a first fill layer in the first batch of layers.

7. A method for forming an implant, the method comprising: Print multiple layers sequentially to form a three-dimensional (3D) printed structure, wherein each layer is printed according to a fill pattern, the fill pattern of each layer comprising a set of fill lines, wherein the plurality of layers (71, 72) are printed on top of each other so as to form a plurality of hollow channels (21) comprising walls within the implant, wherein each hollow channel comprises a skewed wall, wherein the skewed wall is formed by segments of the fill line of a plurality of alternating layers in the layers of the printed structure, wherein the segments of the fill line are oriented in a first direction and are arranged above each other with a lateral offset, wherein the lateral offset is a dimension in a direction parallel to a first outer surface of the implant, wherein the lateral offset is greater than zero and less than 50% of a lateral channel dimension, wherein adjacent hollow channels of the plurality of hollow channels (21) are separated from each other by the wall, wherein a wall of a first hollow channel is a wall of a second directly adjacent hollow channel, wherein at least one of the plurality of hollow channels (21) extends between a first outer surface of the implant and a second outer surface of the implant, Wherein the at least one hollow channel is oriented in a direction (53) that is inclined relative to a reference axis that is perpendicular to the first outer surface of the implant.

8. The method according to claim 7, further comprising: providing a channel direction vector, the channel direction vector defining a tilt of a channel to be formed; specifying a hole size of a first hole of a layer to be formed at a first height, wherein the first hole is represented by a first line segment; as well as A hole size of a second hole of a layer to be formed at a second height is specified, wherein the second hole is represented by a second line segment, the first hole and the second hole belonging to the same channel to be formed.

9. The method according to claim 8, further comprising: The convergence point of the channels to be formed is determined by the following operations: calculating a first orientation line by connecting the left endpoints of the first line segment and the second line segment; Calculating a second orientation line by connecting the first line segment and the right end point of the second line segment, the direction vector being located on the second orientation line; as well as The intersection of the first orientation line and the second orientation line is calculated to determine the convergence point of the channel to be formed.

10. The method according to claim 9, wherein: The point of convergence is located outside the first outer surface or outside the second outer surface of the implant to be formed.

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