Medical devices produced by additive manufacturing

Abstract

To provide a medical instrument produced by a method which has high cost-effectiveness and high degree of automatic operation.SOLUTION: A medical instrument (1) has at least a first instrument branch (3) and a second instrument branch (2) that are relatively movable to each other. The first instrument branch (3) is configured as a male instrument branch (3) provided with a male bearing part (9), and the second instrument branch (2) is configured as a female instrument branch (2) provided with a female bearing part (6) having a through opening (10). The first instrument branch (3) is arranged in the second instrument branch (2) so that the male bearing part (9) goes through the through opening (10) of the female bearing part (6), and the instrument (1) is produced by using an addition production method.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a medical instrument having at least a first instrument branch and a second instrument branch movable relative to each other, the first instrument branch being a male instrument branch with a male bearing portion and the second instrument branch being formed as a female instrument branch with a female bearing portion having a through opening, the first instrument branch being arranged on the second instrument branch such that the male bearing portion passes through the through opening of the female bearing portion. The present invention further relates to a method of manufacturing a medical instrument by additive manufacturing. [Background technology]

[0002] The manufacture of conventional surgical instruments with a box lock is disadvantageously relatively complicated. Such instruments with a box lock are scissors, clamps, forceps and other similar instruments with two instrument branches / instrument parts that can be positioned relative to each other, in particular by swinging. The two instrument branches are designed and attached so that one of them penetrates the other, one branch is inserted into the box of the other, hence the name "box lock". Usually, the two instrument branches are pre-manufactured separately, for example by deformation and / or machining. The branches thus pre-manufactured are then inserted and pressed against each other by expanding the closing part of the female instrument branch. Additional work steps such as drilling, grinding, leveling, hardening and / or brushing may be required.

[0003] A disadvantage of the production of such known instruments is that a large amount of time and effort is generally required due to the large number of operations, which results in a costly and tool-intensive production in that there is almost no possibility of automation and may even require a large amount of manual effort. Another disadvantage of conventional surgical instruments with a box lock is that their branches, which are relatively movable relative to one another, are usually connected to one another via a (pivot) axis. Therefore, apart from the above-mentioned rotation relative to one another, there are always areas between the branches that are difficult to access for cleaning or sterilization purposes and no other possibilities for relative positioning exist. Summary of the Invention [Problem to be solved by the invention]

[0004] The objective on which the present invention is based over the prior art is to provide a medical device which does not have the above-mentioned prior art problems with regard to manufacturing engineering. In particular, its manufacture is cost-effective, has a high degree of automation and preferably allows for (largely) tool-free assembly. Furthermore, said device should be improved in its suitability for cleaning and sterilization compared to the prior art. [Means for solving the problem]

[0005] According to the present invention, this object is solved by a medical instrument having at least a first instrument branch / instrument portion and a second instrument branch / instrument portion which are movable relative to each other. The first instrument branch is configured as a male instrument branch with a male bearing part. The second instrument branch is configured as a female instrument branch with a female bearing part with a through opening (push-through box). The first instrument branch is arranged in the second instrument branch such that the male bearing part passes through the through opening (push-through box) of the female bearing part. The instrument according to the invention is characterized by the fact that it (at least the first instrument branch) is manufactured using additive manufacturing.

[0006] With regard to the method, the object is solved by a method for manufacturing a medical device, in particular a device according to the invention, in particular a device according to one of the attached claims, by an additive manufacturing method, whereby at least a first male instrument branch / instrument part with a male bearing part and a second instrument branch / instrument part as a female instrument branch with a female bearing part (push-through box) with a through opening are formed, whereby at least the male bearing part is additively manufactured (in accordance with commonly known generative / additive manufacturing methods) so as to pass through the through opening of the female bearing part.

[0007] The reason why it is successful to manufacture two tool branches inserted relative to each other by additive manufacturing is that, for example, in an open position of the tool, the distance between the two tool branches is such that they do not intersect during manufacturing and can then be moved / rocked 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 manufacturing step. This means that both branches are manufactured at the same time, whereby they are additively or productively directly assembled to each other in the intended configuration and arrangement, i.e. with the box lock. Also, unlike the prior art, where the two branches are first made separately to each other and then assembled to each other, according to the invention the two branches are connected to each other during their manufacture in the desired way, in particular connected / interlocked, so that they can be positioned relative to each other as intended. Advantageously, the previously required final assembly step (interlock) of the two branches, which is tool-intensive, is not necessary. A further advantage is that the invention allows a significant reduction in the number of manufacturing steps required compared to current manufacturing methods, saving time and costs. However, it is still possible to harden, drill, rivet and / or surface treat said instruments after additive manufacturing depending on the respective requirements.The present invention covers almost all types of surgical instruments with a box lock, e.g. forceps, clamps, scissors, etc.

[0008] The device according to the invention preferably has a closure area where the two branches of the device are connected or joined. This closure area / joining area / connection area is formed by the male bearing part of the first branch (which can also be called joining, connecting or closing part) and the female bearing part / push-through box of the second branch (which can also be called joining, connecting or closure part). The male part is received in or passes through a through opening of the female part.

[0009] Advantageous embodiments of the invention are also claimed in the dependent claims and are explained in more detail below.

[0010] In a preferred embodiment of the invention, the female bearing part completely surrounds or encircles the through opening, which allows a particularly stable and precise guiding of the two branches relative to one another.

[0011] In another preferred embodiment, a play is provided between the male bearing part of the first instrument branch and the female bearing part of the second instrument branch, such that in a relative position of the first instrument branch with respect to the second instrument branch, which can also be called a manufacturing position since the instruments are manufactured in that position, the first and second instrument branches can be arranged without contacting each other or inside each other. In particular, the bearing parts of both instrument parts can comprise three separate part areas, namely a central bearing or closing area, where the two instrument branches overlap each other in all positions (functional and manufacturing positions), and adjacent lateral bearing or closing areas on both sides of each other, which overlap each other only when, for example, in the closed state of the instruments, the two branches are in different angular positions (functional positions) other than the manufacturing position. If, according to a preferred embodiment, the area of ​​the male bearing part covered by the female bearing part in the manufacturing position is configured to have a height that is smaller than the positive width of the through opening, it can be further facilitated to prevent mutual contact between the two branches within the framework of additive manufacturing. In particular, the two tool parts may be configured such that in an open position (manufactured position), for example between 80 degrees and 120 degrees, they are spaced apart from each other in the fully closed region and do not contact each other. This may be achieved, for example, by making the central closure area of ​​the male instrument portion and / or the central closure area of ​​the female instrument portion thinner than each of the lateral closure areas. This ensures that the central closure areas of the two tool parts do not touch each other in any position, thereby avoiding a material connection of the two tool parts during manufacture. When the tool is closed to a certain extent (functional position), the lateral closure areas overlap or even contact each other (directly or indirectly, as will be described in more detail later, e.g. by contact structures or contact members), but they do not overlap in the manufacture position / state, nor can they touch each other.

[0012] According to one preferred embodiment, in the manufacturing position, an angle of about 80° to about 120° is formed between the first and second instrument branches, preferably about 85° to about 115°, and particularly preferably about 90° to about 110°. Preferably, in the manufacturing position, the instrument branches are at an angle or position relative to one another that is unlikely to occur when the instrument is actually used as intended. This makes it particularly easy to ensure that the instrument functions safely (good swing guidance in the functional position(s)).

[0013] According to an advantageous embodiment of the invention, contact structures are formed on the first and / or second instrument branch. These serve to establish a mutual contact between the first and second instrument branches in a functional / use position away from the manufacturing position. This allows a defined, reliable and stable guidance of both branches to and against each other during actual use to be achieved, despite the spatial separation of both branches from each other caused by the manufacturing. According to one embodiment, the male branch comprises at least one contact structure in the closure area or in the male bearing part, in the form of a bump or a small bench, which reduces the play in the instrument closure when the instrument is closed. Preferably, two such small benches or bumps are formed or arranged on each side. According to the invention, a particularly effective play compensation for simultaneous easy actuation can be achieved by forming elastic tongues in the area of ​​the bump or the small bench. A spring force is thus applied between both branches, the strength of which determines the actuation force and the guidance of the instrument. In the case of the embodiment described below which comprises a plug, it is practical to have the two parts positioned and fixed relative to each other by means of a separate axial member which passes through corresponding recesses formed in both branches to define a clear movement of the two parts relative to each other.

[0014] The first and second instrument branches can be arranged pivotally relative to one another by means of a push-through shaft, which in principle can be configured as a rivet.

[0015] Alternatively, one of the instrument branches can be provided with a guide projection rising towards the other instrument branch, which engages in a corresponding arc-shaped recess in the other instrument branch for pivotal positioning of both instrument branches (motion link guide). In particular, the recess can be formed in the female bearing portion, in particular on both sides. The guide projection can be formed in the male bearing portion, in particular on both sides.

[0016] A particularly great advantage is that such an embodiment does not require a shaft, a push-through shaft or a rivet. On the other hand, this reduces the number of components of the tool, so that at least one work step is omitted in its production compared to a tool with a push-through shaft. Another essential and important advantage is that the tool can be produced with a defined closing / opening / working force. This is due to the fact that the forces acting between the male and female branches as a result of their interaction, in particular their mutual adaptation, can be generated in a defined manner, which is only achievable with difficulty in tools with a riveting-through shaft. In the riveting process, both sides of the closure box of the male branch are usually deformed, in particular compressed. It is disadvantageous that the deformations cannot be influenced or can only be influenced in a defined manner with difficulty, so that a validation of the riveting process can only be performed insufficiently with respect to certain forces (closing, opening, working forces). In practice, this problem extends to the extent that, when several riveting machines are used in production, each machine produces tools with a different movement, even if both the machine and its parameters are identical. This creates tools that are very different from each other in their movement (actuation forces), which can only be corrected by extensive reworking to the extent that approximately the same closing forces, i.e. approximately the same movements, can be achieved. It is a great advantage that the above-mentioned problems can be avoided by the embodiment with the motion link guidance. In particular, the projections and grooves, in particular the arc-shaped projections and their corresponding arc-shaped grooves, can be formed by additive manufacturing, in particular by laser sintering processes, in particular on both side surfaces of the lateral closing areas or bearing parts of the male and female tool parts, which are arranged concentrically with respect to the intended center of rotation of the two tool branches. It is particularly advantageous that the grooves and projections further comprise an approach chamfer, so that each projection can be inserted in a funnel-like manner into the corresponding groove when the two tool branches are moved from the manufacturing position to the use position. The concentricity of the grooves and projections makes it possible to eliminate the need for a separate component shaft, which makes it possible to save a manufacturing step.The projections can be in the form of a continuous arc or a number of individual projections arranged on one or on corresponding arcs. According to one embodiment, the 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 arranged on the lateral closure parts. Furthermore, the lateral ends of the arc-shaped grooves and / or the arc-shaped projections can be provided with inclined surfaces. These form a kind of entrance funnel that facilitates the entry of the projections into the grooves. These inclined surfaces can also be configured in such a way that a true closure (i.e. no more wobbling between the two parts) is only formed shortly before the device is in the closed position.

[0017] According to a preferred embodiment, the tool has a restricting structure, which ensures that the tool cannot be easily or accidentally moved from one of its functional / use positions to the manufacturing position during use. The restricting structure is therefore configured in such a way that when the tool is transferred from the use position to the manufacturing position, a relative movement of both tool branches is prohibited (resistance / threshold to the movement), which must be overcome by applying a larger operating force by the user. It can also be said that in this way a surmountable stop is formed for the opening movement of the tool. This has the advantage that during normal use the tool does not open beyond a certain point, thus preventing it from being transferred to the manufacturing position by mistake. However, it is easily possible to bring the tool to the manufacturing position by applying an operating force that overcomes the restriction. In the manufacturing position, both tool branches (within the restriction) can be moved and / or rotated in multiple directions relative to each other, thereby facilitating easy and effective cleaning, maintenance and sterilization. At the same time, it is ensured that the manufacturing position cannot be reached by mistake during normal use of the tool. The restriction or surmountable stop can be achieved, for example, by forming different groove depths. Alternatively, this can be achieved by arranging the recesses and protrusions in such a way that they can be selectively engaged with each other, i.e. depending on the opening angle of both branches. For example, there can be a number of concentric corresponding grooves and protrusions. If a virtual pivot axis is formed by the grooves and protrusions, the remaining areas of the lateral closing surfaces can only partially or not at all come into contact with each other.

[0018] Both branches may in particular consist or be made of metal and / or ceramic.

[0019] According to a preferred embodiment, at least one of the branches, in particular at least one of the bearing parts, can be provided with a recess into which a plug can be pressed, which determines the movement or operating force of the instrument. The plug can be made of a material different from that of the instrument part, for example a plastic material such as PEEK, PE, PA, etc., or another metallic material such as austenitic steel.

[0020] The (lateral) distance between the two central closed areas / bearing parts depends on the manufacturing accuracy of the machine used for additive manufacturing. This distance is preferably between 0.05 mm and 0.3 mm. The two tool parts can be configured to be inserted into each other already in a 3D CAD model. This 3D CAD model can be the basis for the machine used for additive manufacturing, such as a laser sintering machine.

[0021] It can be said that by the present invention it is for the first time possible to manufacture a surgical instrument using additive or generative manufacturing methods without the instrument parts or instrument branches being connected to one another in a box lock, in particular without them connecting or merging with one another in a material lock. The entire device is manufactured using generative or additive manufacturing methods. The present invention relates both to a method for manufacturing such an instrument and also to said instrument itself with an appropriately formed box lock.

[0022] The invention will now be explained in more detail by way of example with reference to the drawings, which show: [Brief description of the drawings]

[0023] [Figure 1] 1A-1C are two different perspective views of the scalpel instrument branch. [Diagram 2] FIG. 13 is a perspective view of the male instrument branch. [Diagram 3] FIG. 13 is an enlarged detail of the male instrument branch in the region of the bearing portion. [Figure 4] FIG. 1 is a plan view of the device in the manufacturing position. [Diagram 5]FIG. 2 is a cross-sectional view of an enlarged area of ​​both bearing parts in the manufacturing position. [Figure 6] FIG. 2 is a perspective view of the area of ​​both bearing parts in the manufacturing position. [Figure 7] FIG. 2 is a perspective view of an area of ​​both bearing portions of an embodiment in a manufacturing position. [Figure 8] FIG. 2 is a perspective view of an area of ​​both bearing portions of an embodiment in a manufacturing position. [Figure 9] FIG. 2 is a perspective view of an area of ​​both bearing portions of one embodiment in a manufacturing position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Said drawings are only schematic in nature and serve only for understanding the invention.

[0025] 1 and 2 show a surgical clamp 1 as an example of an instrument 1 according to the invention. FIG. 1 shows its female branch 2, and FIG. 2 shows its male branch 3. The female branch 2 has a handle portion 4, a clamp portion 5 and a female bearing portion (push-through box) 6 arranged therebetween. Similarly, the male branch 3 has a handle portion 7, a clamp portion 8 and a male bearing portion 9 arranged therebetween. The female bearing portion 6 has a push-through / through opening 10. Although FIGS. 1 and 2 are provided only to more clearly present and explain the two branches 2, 3, it is noted that the clamp 1 of the invention, manufactured according to the invention using additive or generative manufacturing methods, cannot be disassembled / assembled, i.e. the two branches 2, 3 cannot be separated from each other without being destroyed.

[0026] Figure 3 shows the male bearing part 9 enlarged in a side view. The male bearing part 9 has three separate parts, namely a central bearing or closing area 11, where the two instrument branches 2, 3 overlap each other in all their relative positions, and lateral bearing or closing areas 12 or 13, located adjacent to it on both sides and overlapping only when the two branches 2, 3 are in a different angular position than they are in the manufacturing position (shown in Figure 4), e.g. in the closed state of the instrument 1. The central male bearing part 11 has a height h that is smaller than the height H of the through opening 10 of the female bearing part (see in particular Figure 5). As a result of this formation, in the manufacturing position, there is a (double) gap between the male branch 3 and the female branch 2, respectively, with a gap height of e.g. 0.05 mm to 0.3 mm, and therefore no contact between them. The two branches 2, 3 can therefore be manufactured in situ by additive or generative manufacturing methods, such as laser sintering, without being specifically connected or baked, ensuring the relative mobility of these two branches 2, 3 with respect to each other.

[0027] In order to achieve the desired mutual guidance of the branches 2, 3 when using the instrument 1, according to the embodiment shown in Figure 6, the lateral bearing or closing areas 12, 13 are formed with an increased height h' compared to the central bearing part 11. Said height h' corresponds substantially to the height H of the through opening 9, so that the two branches 2, 3 bear against each other in a position away from the manufacturing position, i.e. in the use position, thereby achieving the desired guidance.

[0028] It should be noted that the additive manufacturing of the device 1 is performed in the manufacturing position shown in Fig. 4, whereby the two branches 2, 3 are additively constructed in an inserted state. This means that the branches 2, 3 are not manufactured separately and then connected / inserted into each other, but their additive construction is performed simultaneously with the desired box lock. Fig. 4 illustrates the manufacturing position in which the angle α between the branches 2, 3 is approximately 90 degrees.

[0029] Whereas the two branches 2,3 of the embodiment of Figure 6 are pivotally connected to one another by a push-through shaft 14 inserted through corresponding shaft holes 19 of the branches 2,3, Figure 7 shows an embodiment which differs from that construction in that it does not comprise such a shaft. The male bearing part 9 is provided on either side thereof with two substantially arc-shaped ridges 15. The female bearing part 6 is provided with correspondingly arcuate recesses 16 on both sides of the through opening 10. The raised part 15 and the recesses 16 are arranged to engage with each other such that they form a guide structure or gateway, by which the two branches 2, 3 are guided relative to each other in the functional position during pivoting. If the branches 2, 3 are not in the functional position but in the manufacturing position, the recesses 16 and the raised part 15 do not engage and therefore there is no contact between the branches 2, 3.

[0030] 8 shows an embodiment of the instrument 1 in which contact structures are formed in the male bearing part 9, preferably in the form of plugs 17 that are inserted or pressed into recesses (these can be glued in the form of nubs). The plugs 17 are configured to determine the movement or operating forces of the instrument 1 and can be made of a material different from the instrument parts, for example a plastic such as PEEK, PE, PA, or another metallic material such as austenitic steel.

[0031] FIG. 9 shows a further embodiment in which the contact structure is made in the form of a resilient tongue 18, at the free end of which a plug or nub 17 can be arranged, preferably as in FIG.

[0032] It is also noted that it is possible to combine the embodiment without a support shaft of Fig. 7 with the contact structure of Fig. 8 or 9. Also, for the embodiment without a support shaft of Fig. 7, a bearing area formed as in Fig. 3 can be advantageously used. [Explanation of symbols]

[0033] 1 Instrument, clamp 2 Female branch / instrument section 3 Male branch / instrument part 4 Handle part 5 Clamping part / Cutting part 6 Female bearing part / push-through box 7 Handle part 8 Clamping part / Cutting part 9 Male bearing part / Bush-through part 10 Through hole / longitudinal slit 11 Central bearing part (bush-through part) 12 Side bearing part / contact structure (bush-through part) 13 Side bearing part / contact structure (bush-through part) 14 Push-through shaft / rivet 15 Ridge 16 Recess 17 Plug / Contact Structure / Bolt / Pin / Nub 18 Spring tongue / contact structure 19 Shaft opening α angle h Height h' height H Height

Claims

1. A medical instrument (1) having at least a first instrument branch (3) and a second instrument branch (2) movable relative to each other, said first instrument branch (3) being configured as a male instrument branch (3) with a male coupling portion (9) and said second instrument branch (2) being configured as a female instrument branch (2) with a female coupling portion (6) having a through opening (10); the first instrument branch (3) is arranged on the second instrument branch (2) such that the male coupling portion (9) passes through the through opening (10) of the female coupling portion (6), said medical instrument (1) being manufactured using additive manufacturing methods such that both instrument branches (2, 3) are manufactured simultaneously, and during the manufacturing of both instrument branches (2, 3) the male coupling portion (9) of the first instrument branch (3) and the female coupling portion (6) of the second instrument branch (2) are coupled to each other, The medical instrument (1) is characterized in that one of the two instrument branches (2, 3) has a guide protrusion (17) that protrudes toward the other instrument branch (2, 3) and engages with a corresponding arc-shaped recess (16) formed in the other instrument branch (2, 3) for pivotal positioning of the two instrument branches (2, 3).

2. The medical device (1) according to claim 1, wherein the female coupling portion (6) completely surrounds the through opening (10).

3. in a manufacturing position of the first instrument branch (3) relative to the second instrument branch (2), a play is provided between the male coupling portion (9) of the first instrument branch (3) and the female coupling portion (6) of the second instrument branch (2) such that they are arranged without contact with each other, Each of the coupling portions (6, 9) of both instrument branches (2, 3) has a central coupling portion, 3. Medical device (1) according to claim 1 or 2, wherein in the manufacturing position, the two device branches (2, 3) overlap each other only at the central joint portion.

4. 4. The medical device (1) according to claim 1 or 3, wherein the area (11) of the male coupling part (9) which is covered by the female coupling part (6) in the manufacturing position has a lower height (h) than the through opening (10).

5. The medical instrument (1) according to any one of the preceding claims, wherein in the manufacturing position an angle between the first instrument branch (3) and the second instrument branch (2) is formed of between 80 degrees and 120 degrees.

6. contact structures (12, 13, 17, 18) are formed on the first instrument branch (3) and / or the second instrument branch (2) for establishing mutual contact between the first instrument branch (3) and the second instrument branch (2) in a use position displaced from a manufacturing position, The medical device (1) according to any one of claims 1 to 5, wherein each of the connecting portions (6, 9) of both instrument branches (2, 3) has a central connecting portion where the two instrument branches (2, 3) overlap each other in the use position and in the manufacturing position, and adjacent lateral connecting portions on both sides where the two instrument branches (2, 3) overlap each other only in the use position.

7. The medical instrument (1) according to any one of claims 1 to 6, further comprising a restricting structure configured such that when the medical instrument (1) is transferred from a use position to a manufacturing position, the relative movement of the two instrument branches (2, 3) is restricted, and this restriction must be overcome by an operating force by a user that exceeds the restriction.

8. 2. The medical instrument (1) according to claim 1, wherein the guiding projection (17) and the recess (16) are arranged concentrically with respect to the centre of rotation of the first instrument branch (3) and the second instrument branch (2).

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