ADDITIVELY MANUFACTURED MEDICAL INSTRUMENT AND METHOD FOR PRODUCING SUCH AN INSTRUMENT

Description

[0001] The invention relates to a medical instrument comprising at least a first instrument branch and a second instrument branch, which are movable relative to one another. The first instrument branch is designed as a male instrument branch with a male bearing section, and the second instrument branch is designed as a female instrument branch with a female bearing section having a through-opening. The first instrument branch is arranged on the second instrument branch in that the male bearing section extends through the through-opening of the female bearing section. It further relates to a method for producing a medical instrument using an additive manufacturing process.

[0002] The disadvantage is that the production of a conventional surgical instrument with a through-hole closure is relatively complex. Examples of such instruments with a through-hole closure include scissors, clamps, forceps, or similar instruments that have two instrument branches / instrument parts that can be positioned relative to each other, particularly by pivoting. The two instrument branches are designed and assembled in such a way that one of them penetrates the other; one could also say that one branch is inserted through the other, hence the term "through-hole closure." Typically, the two instrument branches are prefabricated separately, for example, by forming and / or machining. The prefabricated branches are then inserted into each other by expanding a closing area of the female instrument branch and pressed together.Additional operations may be required, such as drilling, grinding, straightening, hardening and / or brushing.

[0003] A disadvantage of manufacturing such known instruments is that a high level of effort and numerous work steps is usually required. This means that production is cost-intensive and tool-intensive, there are hardly any automation options, and a high level of manual effort can even be required. A further disadvantage of known medical instruments with a push-through closure is that their branches, which can be moved relative to one another, are usually coupled to one another via a (pivoting) axis. There is therefore always an area between the branches that is difficult to access for cleaning or disinfection purposes because, apart from the aforementioned rotation relative to one another, there are no other options for relative positioning. Examples of such instruments are disclosed, for example, in US 2017 / 0 020 571 A1, WO 2012 / 021 779 A2, EP 2 873 381 A1, US 5 514 147 A or US 2 305 156 A1.

[0004] The object underlying the invention in view of this prior art is to provide a medical instrument that, in terms of manufacturing technology, is not burdened by the problems of the prior art described above. Its production should be particularly inexpensive, have a high degree of automation, and preferably enable (largely) tool-free assembly. Furthermore, the instrument should be improved over the prior art with regard to its suitability for cleaning and sterilization. This object is achieved according to the invention by a medical instrument having the features of patent claim 1 and a method having the features of patent claim 8.

[0005] In particular, the object is thus achieved by a medical instrument according to claim 1 comprising at least a first instrument branch and a second instrument branch which are movable relative to one another.

[0006] The first instrument branch is designed as a male instrument branch with a male bearing section. The second instrument branch is designed as a female instrument branch with a female bearing section (through-hole) having a through-opening. The first instrument branch is arranged on the second instrument branch in that the male bearing section passes through the through-opening (through-hole) of the female bearing section. The instrument according to the invention is characterized in that it (at least the first instrument branch) is manufactured using an additive manufacturing process.

[0007] With regard to a method, the object is achieved by the method according to claim 8 for producing a medical instrument, in particular an instrument according to the invention, in particular an instrument according to one of the appended claims, by means of an additive manufacturing method, according to which at least a first, male instrument branch is formed with a male bearing section and a second instrument branch is formed as a female instrument branch with a female bearing section (through-box) having a through-opening, wherein at least the male bearing section is produced additively (according to the generally known generative / additive manufacturing method) passing through the through-opening of the female bearing section.

[0008] The production of two nested instrument branches using an additive manufacturing process is achieved by, for example, ensuring that in a certain open position of the instrument, the distance between the two instrument branches is such that the branches do not merge during production and can subsequently be moved / pivoted relative to each other. According to the invention, the branches are manufactured in such a way that they are produced separately from each other in a single production step. This means that both branches are manufactured simultaneously, whereby they are simultaneously assembled additively or generatively in their intended arrangement and configuration, i.e., with a push-through connection.It can also be said that, unlike the prior art, where the two branches are initially produced separately and subsequently assembled together, according to the invention the two branches are coupled together in the desired manner during production, in particular they are coupled / inserted into one another in a manner that can be positioned relative to one another as intended. This advantageously eliminates the previously required tool-intensive final assembly step (inserting the two branches into one another). A further advantage is that the invention can significantly reduce the number of required manufacturing steps compared to current manufacturing methods, which saves time and costs. However, the instrument can still be hardened, drilled, riveted and / or surface treated after additive manufacturing, depending on the respective requirements.The invention relates to almost all types of surgical instruments with a push-through closure, for example forceps, clamps, scissors, etc.

[0009] The instrument according to the invention preferably has a terminal area in which the two branches of the instrument are connected or coupled to each other. This terminal area / coupling area / connecting area is formed by the male bearing section (which can also be referred to as a coupling section, connecting section, or terminal section) of the first branch and the female bearing section / through-box (which can also be referred to as a coupling section, connecting section, or terminal section) of the second branch. The male section is received in or penetrates the through-opening of the female section.

[0010] Advantageous embodiments of the invention are also claimed in the subclaims and are explained in more detail below.

[0011] A preferred embodiment of the invention provides that the female bearing section completely surrounds or encloses the through-hole. This enables particularly stable and precise guidance of the two branches relative to each other.

[0012] The invention provides that there is play between the male bearing section of the first instrument branch and the female bearing section of the second instrument branch in a relative position of the first instrument branch to the second instrument branch, which can also be referred to as the manufacturing position since the instrument is manufactured in this position, such that the first instrument branch and the second instrument branch can be arranged on / in each other without contact.The bearing sections of both instrument parts each have, in particular, three individual sub-areas: a central bearing or end area in which the two instrument branches overlap in every position (functional position and production position), and adjacent lateral bearing or end areas on both sides in which the two branches only overlap when they are in a different angular position (functional position) to each other than in the production position, for example when the instrument is closed. Mutual contact between the two branches during additive manufacturing can be prevented particularly easily by, according to a preferred embodiment, the area of the male bearing section covered by the female bearing section in the production position having a smaller height than the clear width of the through-opening.In particular, the two instrument parts can be designed such that, in a specific opening position (production position), for example, between 80° and 120°, they are spaced apart across the entire closure area and do not contact or touch each other. This can be achieved, for example, by making the central closure area of the male instrument part and / or the central closure area of the female instrument part thinner than the respective lateral closure areas. In this way, the central closure areas of the two instrument parts do not touch at any position, thus avoiding a material connection between the two instrument parts during production.While the lateral closing areas overlap and even touch each other (directly or indirectly, for example, with contact structures or contact elements described in more detail below) when the instrument is closed to a certain degree (functional position), they do not overlap in the manufacturing position / position, so that they cannot touch each other.

[0013] According to a preferred embodiment, in the manufacturing position, the angle between the first instrument branch and the second instrument branch is approximately 80° to approximately 120°, preferably approximately 85° to approximately 115°, and particularly preferably approximately 90° to approximately 110°. Preferably, in the manufacturing position, the instrument branches are at such an angle or in such a position relative to one another that does not occur, or only with a low probability, during intended use of the instrument in practice. In this way, reliable function of the instrument (good pivoting guidance in the functional position(s)) can be ensured particularly easily.

[0014] An advantageous embodiment of the invention provides that contact structures are formed on the first instrument branch and / or on the second instrument branch. These serve to mutually contact the first instrument branch and the second instrument branch in a functional / use position that differs from the manufactured position. In this way, despite the spatial separation of the branches from one another due to manufacturing reasons, a defined, secure, and stable guidance of the branches relative to and against one another during practical use can be achieved. According to one embodiment, the male branch has at least one contact structure in the form of a raised portion or a ledge in the closing area or in the male bearing section, which reduces the play in the instrument closure when the instrument is closed. Preferably, two such ledges or ledges are formed or arranged on each side.Particularly effective play compensation combined with easy operation can be achieved according to the invention by forming resilient tongues in the area of the raised part or the bench. This exerts a spring force between the branches, the magnitude of which determines the actuation force and guidance of the instrument. In an embodiment with a plug described below, it is advantageous for the branches to be arranged and secured relative to each other by means of a separate axle element that passes through corresponding recesses in the branches, in order to define a clear movement of the two parts relative to each other.

[0015] According to an embodiment no longer forming part of the invention, the first instrument branch and the second instrument branch can be pivotably positioned relative to each other by means of a through-hole. Such a through-hole can generally be designed as a rivet.

[0016] According to the invention, one of the instrument branches has a guide projection that extends toward the other instrument branch and engages in a correspondingly formed circular-arc-shaped recess on the other instrument branch (sliding guide) for pivotally positioning the instrument branches. In particular, the recess can be formed on the female bearing section, in particular on both sides. The guide projection can be formed on the male bearing section, in particular on both sides.

[0017] It is particularly advantageous that with such a design there is no need for an axle, through-axle or rivet. This means that the instrument has one less component, meaning that at least one production step is eliminated compared to an instrument with a through-axle. A further significant and important advantage is that the instrument can be manufactured with a defined closing force / opening force / actuating force. This is because the interaction of the male and female branches, in particular the forces acting between them as a result of their mutual fit, can be defined, which is difficult to achieve with an instrument with a riveted through-axle. During the riveting process the two sides of the end box of the male branch are usually deformed, in particular pressed together.The extent of such deformation is disadvantageously difficult or impossible to influence in a defined manner, so that a riveting process is difficult to validate for a specific force (closing force, opening force, actuating force). In practice, this problem goes so far that when several riveting machines are used in production, each machine produces instruments with a different gear, even though both the machines and their parameters are identical. The result is instruments that differ significantly from one another in terms of gear (actuating force), which can only be corrected through extensive rework to the extent that an approximately identical closing force, i.e. an approximately identical gear, can be achieved. The fact that the above problem can be avoided with a design with a slotted guide is a major advantage.The projections and grooves, in particular circular arc-shaped projections and corresponding circular arc-shaped grooves, can be formed, in particular during additive manufacturing, in particular during a laser sintering process, in particular on the opposing surfaces of the lateral end regions or bearing sections of the male and female instrument parts. These are arranged concentrically to the intended rotation center of the two instrument branches. It is particularly advantageous if the grooves and projections are also provided with run-on bevels so that the respective projection can be inserted into the corresponding groove in a funnel-like manner when the two branches are moved from the manufacturing position to the use position. The concentricity of the grooves and projections eliminates the need for an axis as a separate component, and manufacturing steps can be saved.The projections can be in the form of continuous circular arcs or in the form of one projection or several individual projections arranged on a corresponding circular arc. One embodiment is characterized in that grooves and / or projections are provided with a friction-reducing layer. Alternatively, they can be made of a suitable material, such as PEEK, PE, etc., and can be mounted on the lateral end sections. In addition, inclined surfaces can be provided at the lateral ends of the circular arc-shaped groove and / or the corresponding projection. These form a type of inlet funnel, which facilitates the projection running into the groove. The inclined surfaces can also be designed in such a way that the actual closure (i.e. there is no longer any wobbling between the two parts) only occurs shortly before the instrument is in the closed position.

[0018] According to a preferred embodiment, the instrument has a restraining structure. This serves to prevent the instrument from being easily or accidentally moved from one of its functional / use positions into the production position during use. The restraining structure is therefore designed such that when the instrument is transferred from a use position to the production position, the relative movement of both instrument branches is inhibited (movement resistance / threshold), which must be overcome by an increased actuating force from the user. One could also say that this creates an surmountable stop for an opening movement of the instrument. This has the advantage that the instrument does not open beyond a certain point during regular use, thus preventing it from being accidentally transferred into the production position.Nevertheless, it is possible to easily bring the instrument into the production position by exerting an actuating force that overcomes the inhibition. In the production position, the instrument branches can be moved and / or rotated relative to one another (within limits) in several directions, which facilitates simple and effective cleaning, maintenance, and disinfection. At the same time, it is ensured that the production position is not inadvertently reached during regular use of the instrument. The inhibition or the surmountable stop can be achieved, for example, by forming grooves of different depths. Alternatively, it can be achieved by positioning recesses and projections in such a way that they can be selectively engaged with one another, i.e., depending on the opening angle of the branches. For example, several concentric corresponding grooves and projections can be provided.In the event that the virtual pivot axis is formed by means of grooves and projections, the remaining areas of the lateral end surfaces may only partially touch each other or not at all.

[0019] The branches can in particular consist of / be made of metal and / or ceramic.

[0020] According to a preferred embodiment, a recess can be formed in at least one of the branches, in particular in at least one of the bearing sections. A plug can be pressed into this recess, which determines the action or actuation force of the instrument. The plug can be made of a different material than the instrument parts, for example, a plastic such as PEEK, PE, PA, or another metallic material, such as austenitic steel.

[0021] The (lateral) distance between the two central end areas / bearing sections depends on the manufacturing accuracy of the machinery used for additive manufacturing. It is preferably in a range between 0.05 mm and 0.3 mm. The two instrument parts can be designed so that they fit together in a 3D CAD model. This 3D CAD model can serve as the basis for a machine used for additive manufacturing, for example, a laser sintering machine.

[0022] It can be said that the invention makes it possible for the first time to manufacture surgical instruments using an additive or generative manufacturing process without the instrument parts or branches being joined together in a push-through connection, in particular without being joined or fused together in a material-to-material manner. The entire instrument is manufactured using a generative or additive manufacturing process. The invention relates to both a manufacturing process for such instruments and the instruments themselves with a correspondingly designed push-through connection.

[0023] The invention is explained in more detail below by way of example with the aid of drawings. It shows: Fig. 1 shows a female instrument branch in two different perspective views, Fig. 2 shows a male instrument branch in a perspective view, Fig. 3 shows an enlarged detail of the male instrument branch in the area of the storage section, Fig. 4 shows an instrument in a top view in the production position, Fig. 5 shows an enlarged and sectional view of the area of both storage sections in the production position, Fig. 6 shows a perspective view of the area of both storage sections in the production position, Fig. 7 shows a perspective view of the area of both storage sections of an embodiment in the production position, Fig. 8 shows a perspective view of the area of both storage sections of an embodiment in the production position, and Fig. 9 shows a perspective view of the area of both storage sections of an embodiment in the production position.

[0024] The drawings are merely schematic in nature and serve only to understand the invention.

[0025] The Figures 1 and 2 show a surgical clamp 1 as an example of an instrument 1 according to the invention. Figure 1 shows its female branch 2, while Figure 2 whose male branch 3 is shown. The female branch 2 has a handle section 4, a terminal section 5 and a female bearing section (through-hole box) 6 arranged between them. Similarly, the male branch 3 has a handle section 7, a terminal section 8 and a male bearing section 9 arranged between them. The female bearing section 6 has a through-hole 10. It is expressly pointed out that the representation of the Figures 1 and 2only for the purpose of better illustrating and explaining the two branches 2, 3, but the clamp 1 according to the invention, which is manufactured by means of an additive or generative manufacturing process according to the invention, cannot be disassembled / assembled, i.e. the two branches 2, 3 cannot be separated from one another without being destroyed.

[0026] Figure 3 shows the male bearing section 9 enlarged in a lateral view. It is shown that the male bearing section 9 has three individual sections: a central storage or end section 11, in which the two instrument branches 2, 3 overlap in any position relative to each other, and adjacent lateral storage or end sections 12 and 13, respectively, in which the two branches 2, 3 only overlap when they are in a different angular position relative to each other than in the production position (shown in Figure 4), for example in the closed state of the instrument 1. The central male bearing section 11 has a height h which is smaller than the height H of the through opening 10 of the female bearing section, see in particular in Figure 5 As a result of this design, a (double) gap exists between the male branch 3 and the female branch 2 in the manufacturing position, each with a gap height of, for example, 0.05 mm to 0.3 mm, thus eliminating contact. The two branches 2 and 3 can therefore be manufactured in the manufacturing position using an additive or generative process such as laser sintering, without being bonded or baked together, thus ensuring relative mobility between branches 2 and 3.

[0027] In order to achieve the desired mutual guidance of the branches 2, 3 when using the instrument 1, the lateral bearing or end areas 12, 13 are arranged according to the Figure 6shown embodiment is designed with a height h' that is increased compared to the central bearing section 11. The height h' corresponds essentially to the height H of the through opening 9, so that the two branches 2, 3 support each other in a position deviating from the manufacturing position, i.e. in a position of use, and thus the desired guidance is achieved.

[0028] It should be noted that the additive manufacturing of instrument 1 in the Figure 4 The manufacturing position shown is taken into account, with the two branches 2 and 3 being assembled additively in the push-through state. Therefore, branches 2 and 3 are not manufactured individually and then connected / pushed together; rather, their additive assembly takes place simultaneously with the desired push-through connection. Figure 4 shows a manufacturing position in which the angle α between branches 2, 3 is approximately 90°.

[0029] While the two sectors 2, 3 of the embodiment of the Figure 6 are pivotally connected to each other by a through-axis 14, which is inserted through corresponding axle holes 19 in the branches 2, 3, shows Figure 7a different embodiment without such an axis. The male bearing section 9 is provided on both sides with two essentially circular arc-shaped elevations 15. The female bearing section 6 is correspondingly provided on both sides of the through opening 10 with circular arc-shaped depressions 16. The elevations 15 and the depressions 16 are designed and intended to engage with one another in such a way that they form a guide structure or guideway by means of which the two branches 2, 3 are guided towards one another during pivoting in the functional position range. If the branches 2, 3 are not in a functional position but in the production position, the depressions 16 and elevations 15 are disengaged, so that there is no contact between the branches 2, 3.

[0030] Figure 8shows an embodiment of the instrument 1, in which contact structures in the form of plugs 17, preferably inserted into recesses or pressed into them, are formed on the male bearing cut 9 (and can be glued on in the form of nubs). The plugs 17 are designed to determine the action or the actuation force of the instrument 1 and can be made of a different material than the instrument parts, for example, a plastic such as PEEK, PE, PA, or another metallic material, such as austenitic steel.

[0031] Figure 9 shows a further embodiment in which the contact structures are designed in the form of resilient tongues 18, at the free ends of which plugs or knobs 17 are preferably provided according to the Fig. 8 can be arranged.

[0032] It should also be noted that the version without bearing axis according to Figure 7 with the contact structures according to Figures 8 or 9The axleless version according to Figure 7 a according to Figure 3 trained storage area can be used advantageously. List of reference symbols

[0033] 1Instrument, clamp 2Female branch / instrument part 3Male branch / instrument part 4Handle section 5Clamp section / cutting section 6Female bearing section / push-through box 7Handle section 8Clamp section / cutting section 9Male bearing section / push-through part 10Through opening / longitudinal slot 11Central bearing section (of the push-through part) 12Lateral bearing section / contact structure (of the push-through part) 13Lateral bearing section / contact structure (of the push-through part) 14Through axis / rivet 15Protrusion 16Recess 17Plug / contact structure / bolt / pin / nub 18Spring tongue / contact structure 19Axle hole αAngle hHeight h'Height HHeight

Claims

1. Medical instrument (1) comprising at least a first instrument branch (3) and a second instrument branch (2) which are movable relative to each other, wherein the first instrument branch (3) is formed as a male instrument branch (3) with a male bearing portion (9), and the second instrument branch (2) is formed as a female instrument branch (2) with a female bearing portion (6) having a through opening (10), wherein the first instrument branch (3) is arranged on the second instrument branch (2) in that the male bearing portion (9) penetrates the through opening (10) of the female bearing portion (6), wherein the instrument (1) is manufactured by means of an additive manufacturing method, and there is play between the male bearing portion (9) of the first instrument branch (3) and the female bearing portion (6) of the second instrument branch (2) in a relative position of the first instrument branch (3) to the second instrument branch (2), in such a way that the first instrument branch (3) and the second instrument branch (2) are arranged without contact to each other, wherein one of the instrument branches (2, 3) has a guiding projection (15) rising in the direction of the other instrument branch (2, 3), which engages in a corresponding circular arc-shaped recess (16) on the other instrument branch (2, 3) for the pivotable positioning of the instrument branches (2, 3).

2. Medical instrument (1) according to claim 1, characterized in that the female bearing portion (6) completely surrounds the through opening (10).

3. Medical instrument (1) according to one of claims 1 or 3, characterized in that the area (11) of the male bearing portion (9) covered by the female bearing portion (6) in the manufacturing position has a height (h) which is lower than the through opening (10).

4. Medical instrument (1) according to one of the preceding claims, characterized in that there is an angle α of approx. 80° to approx. 120°, preferably of approx. 85° to approx. 115°, and particularly preferably of approx. 90° to approx. 110° between the first instrument branch (3) and the second instrument branch (2) in the manufacturing position.

5. Medical instrument (1) according to one of the preceding claims, characterized in that contact structures (12, 13, 17, 18) are formed on the first instrument branch (3) and / or on the second instrument branch (2) to establish mutual contact between the first instrument branch (3) and the second instrument branch (2) in a usage position that deviates from the manufacturing position.

6. Medical instrument (1) according to one of claim 1, characterized in that the recess (16) is formed on the female bearing portion (6), in particular on both sides, and the guiding projection (15) is formed on the male bearing portion (9), in particular on both sides.

7. Medical instrument (1) according to one of the preceding claims, characterized in that it has an inhibition structure which is designed in such a way that, when the instrument (1) is transferred from a usage position to the manufacturing position, the relative movement of both instrument branches (2, 3) is inhibited, which must be overcome by an increased actuating force by the user.

8. Method of manufacturing a medical instrument (1) by means of an additive manufacturing method, wherein at least a first, male instrument branch (3) is formed with a male bearing portion (9) and a second instrument branch (2) is formed as a female instrument branch (2) with a female bearing portion (6) having a through opening (10), wherein the male bearing portion (9) is manufactured additively so as to penetrate the through opening (10) of the female bearing portion (6), there is play between the male bearing portion (9) of the first instrument branch (3) and the female bearing portion (6) of the second instrument branch (2) in a relative position of the first instrument branch (3) to the second instrument branch (2), in such a way that the first instrument branch (3) and the second instrument branch (2) are arranged without contact to each other, and wherein the bearing portions (6, 9) of both instrument branches (2, 3) each have a central bearing area (11) in which the two instrument branches (2, 3) overlap in a functional position and a manufacturing position, and lateral bearing areas (12, 13) adjacent on both sides, in which the two instrument branches (2, 3) only overlap when they are in an angular position other than the manufacturing position.

9. Method according to claim 8, characterized in that the instrument (1) is manufactured by means of laser sintering.

10. Method according to claim 8 or 9, characterized in that a gap of approximately 0.3 mm to 0.5 mm is produced between the first instrument branch (3) and the second instrument branch (2).