Surgical instrument

Abstract

The invention relates to a surgical instrument (2), in particular for endoscopic applications, comprising a handpiece (4) and a rotationally drivable tool (6), in particular a milling tool, which is detachably held in the handpiece, wherein: the handpiece (4) has an end portion (10) at the front which delimits a tool receiving opening (14) extending in a longitudinal direction (12); the tool (6) has a tool shank (18) which is insertable into the tool receiving opening (14) of the handpiece in the longitudinal direction (12); the tool (6) has a plate (24) which faces the end portion (10) and is designed and arranged such that an annular gap (26) is formed between the plate (24) and the end portion (10), so that when the tool (6) is rotatably driven, liquid located in said gap is likewise set in rotation and is thereby expelled from the annular gap (26) to the outside due to centripetal forces.

Description

[0001] Title: Surgical instrument

[0002] Description

[0003] The invention relates to a surgical instrument, in particular for endoscopic applications, with a handpiece and with a tool, in particular a milling tool, which is detachably held in the handpiece and can be driven in rotation, wherein the handpiece has a front end section which delimits a tool receiving opening extending in a longitudinal direction, and wherein the tool has a tool shank which can be inserted longitudinally into the tool receiving opening of the handpiece. Instruments of this type are typically operated at very high rotational speeds, in particular up to 80,000 revolutions per minute or more. They are sometimes very expansive in the longitudinal direction for endoscopic applications and are sometimes immersed deep into the patient's body, including the handpiece.The instrument is operated as if immersed in liquid, for example when the surgical area forms a closed cavity that is partially or completely filled with liquid, or when this liquid is pumped out and new liquid is added. This presents the problem that liquid is sucked into the tool holder opening and sometimes escapes again at joints in the handpiece that are far away from it, which is considered disadvantageous and very annoying. On the other hand, a certain degree of rinsability of the handpieces is also advantageous, as this allows them to be cleaned more easily than handpieces closed by sealing elements.

[0004] If helical contours are applied to the shaft of the tool, this only helps to counteract the rising of liquids up the tool shaft in one of the two directions of rotation. However, if the instrument is immersed in liquid up to the tool holder opening, penetration of liquid through the tool holder opening cannot be prevented. The same applies to punctures in the tool shaft which are intended to throw off liquid sucked upwards radially outwards when the tool is rotated. Even the attachment of a ring collar on the shaft of the tool ("throw-off ring") is unable to prevent liquid from penetrating the tool holder opening of the immersed handpiece if the instrument is immersed deeply.

[0005] It has been determined that commercially available tools promote the aspiration of fluid, effectively flooding the handpiece all the way to the motor drive within a few seconds of operation. Endoscopic work cannot be safely performed when immersed in fluid, at least not without the risk of short circuits, electrolysis, corrosion from contact with saline fluid, or similar problems.

[0006] The present invention is therefore based on the object of improving a surgical instrument of the type mentioned at the outset in such a way that even when immersed in liquid, in particular body fluid, in particular in endoscopic applications, the problems described at the outset as a result of penetrating liquid during operation of the instrument do not occur or occur to a lesser extent.

[0007] This object is achieved according to the invention in a surgical instrument of the type mentioned at the outset in that the tool has a shield facing the end section, which shield is designed and arranged in such a way that an annular gap is formed between the shield and the end section, so that liquid located therein is also set in rotation when the tool is driven in rotation and is thus expelled outwards from the annular gap as a result of centripetal forces. The liquid located in the annular gap in the area of ​​the tool receiving opening is therefore also set in rotation by the rotating shield and is prevented from penetrating the tool receiving opening as a result of centripetal forces, in that the liquid is expelled from the annular gap.It has even been shown that, when the instrument is temporarily stopped, any fluid that has entered the handpiece is immediately expelled from the handpiece and through the tool holder opening at the front into the annular gap and from there outward. This allows the instrument to be used even when completely submerged, i.e., beyond the tool holder opening at the front end section.

[0008] According to physical laws, the centripetal forces acting on the rotating fluid within the annular gap act radially outwards; depending on the extent of the annular gap, the fluid is then forced out of the annular gap at an angle to the longitudinal direction, depending on whether it is orthogonal or more or less oblique to the longitudinal direction.

[0009] In a particularly preferred embodiment of the invention, the shield is cup-shaped and overlaps the end section of the handpiece. Thus, when the tool is mounted, the end section of the handpiece is immersed longitudinally into the cup-shaped shield. The annular gap is formed between the shield and the end section of the handpiece.

[0010] It has proven advantageous in this case if the shield has an inner side or an inner side region which delimits the annular gap and which is inclined obliquely to the longitudinal direction, in particular at least 5°, in particular at least 10°, in particular at least 15°, in particular at most 30°, in particular at most 25° to the longitudinal direction. As a result of this inclination, the fluid set in rotation within the annular gap experiences a radially outward-directed displacing force and thus exits the annular gap along the inner side.

[0011] It is also advantageous if the end section is tapered at the front, in particular if it is conical, frustoconical, or dome-shaped. In this case, the annular gap is delimited radially from the inside by an inclined surface of the end section and radially from the outside by the shield. An inner side of the shield can have the same or a slightly greater or slightly smaller inclination than the inclined surface of the end section.

[0012] It is also advantageous if the end section of the handpiece has an end face extending essentially orthogonally to the longitudinal direction and a peripheral side, and if the annular gap extends from the end face over the peripheral side of the handpiece. It is also advantageous if the annular gap extends at an angle to the longitudinal direction in the region of the peripheral side of the end section of the handpiece, and in particular if the peripheral side of the end section itself is inclined to the longitudinal direction.

[0013] With regard to the dimensioning of the annular gap, it is proposed that the annular gap has a gap width which is as small as is technically possible and within the scope of tolerances, in particular a gap width of at least 0.2 mm, in particular of at least 0.3 mm, in particular of at least 0.4 mm, in particular of at least 0.6 mm, in particular of at least 0.8 mm, in particular of at least 1.0 mm and further in particular of at most 8.0 mm, in particular of at most 6.0 mm, in particular of at most 5.0 mm, in particular of at most 4.0 mm, in particular of at most 3.0 mm, in particular of at most 2.0 mm.

[0014] Furthermore, it proves advantageous if the cup-shaped shield is rotationally symmetrical, i.e., concentric, at least on the inside. This allows the fluid in the annular gap to be rapidly set in rotation and expelled from the annular gap due to centripetal forces.

[0015] With regard to the design and attachment of the shield to the shank, it would be conceivable for the shield to be formed integrally with the shank of the tool or to be fixed or securable to the shank of the tool in a rotationally fixed and, for intended use, in any case non-detachable manner, in particular by means of a welded connection, in particular a laser-welded connection, or by means of another, in particular material-locking connection, including an adhesive connection. In this case, it proves advantageous if the shield sits or is attached to the shank in a liquid-tight manner so that no liquid can penetrate into the annular gap between the shank and the shield. Advantageously, the shield comprises a through-opening and can be pushed onto the shank of the tool and secured there using this through-opening.According to a further embodiment of the invention, the shield is not pot-shaped, but is formed by a flange section with a side facing the end section of the handpiece and the tool holder opening. On this side of the flange section, structures are formed which assist in expelling fluid from the annular gap when the tool is driven in rotation. In this case, the shield functions, so to speak, as a radial displacement pump in that the structures exert radially outward-directed displacing forces on the fluid present there when the tool and the flange section are driven in rotation, so that in this way too, penetration of fluid into the tool holder opening is prevented.

[0016] The structures can be designed such that they have radially extending or spirally extending displacement surfaces, or that the structures taper radially outward. Thus, they form a type of impeller or impeller disk.

[0017] In this case, it proves to be advantageous if the structures have a height in the longitudinal direction of up to 0.5 mm and in particular of at least 0.5 mm, in particular of at least 0.8 mm, in particular of at least 1.0 mm and further in particular of at most 5.0 mm, in particular of at most 4.0 mm, in particular of at most 3.0 mm, in particular of at most 2.0 mm.

[0018] As mentioned at the beginning, it proves to be advantageous if the instrument is designed for a rotating drive of the tool with up to 30,000 revolutions / min, in particular with at least 30,000, in particular with at least 40,000, in particular with at least 50,000, in particular with at least 60,000 and in particular with at most 100,000, in particular with at most 90,000, in particular with at most 80,000 revolutions / min.

[0019] Further features, details and advantages of the invention emerge from the appended patent claims and the drawings and subsequent description of preferred embodiments of the invention.

[0020] The drawing shows:

[0021] Figures 1a-c show various views, also partially in section, of a surgical instrument according to the invention with a rotationally drivable tool and a part thereof;

[0022] Figures 2a-b are schematic views of the functioning of the instrument according to the invention;

[0023] Figures 3a-c show different views of another

[0024] Embodiment of the instrument according to the invention with a rotating drivable tool and a part thereof; and

[0025] Figures 4a-c show various views of tools according to a further embodiment of the instrument according to the invention.

[0026] Figures 1a-c show various views of a surgical instrument 2 according to the invention and its components. The surgical instrument 2 comprises a handpiece 4 and a rotationally drivable tool 6, for example in the form of a milling tool. The handpiece 4 is designed here, for example, in the form of a straight housing tube 8 and has a front end section 10. The handpiece 4 further comprises a tool receiving opening 14 which extends in a longitudinal direction 12 of the instrument and opens into the front end section 10.

[0027] The tool 6 here comprises, for example, a milling head 16 and a tool shaft 18 extending in the longitudinal direction, with which the tool 6 can be inserted into the tool receiving opening 14 of the handpiece 4 extending in the longitudinal direction 12 and can be anchored in a rotationally fixed manner for the intended operation of the instrument.

[0028] In the exemplary case, the end section 10 of the handpiece 4 is designed to taper conically at the end face. It forms a front face 20 extending substantially orthogonally to the longitudinal direction 12 and, in this case, a conical peripheral face 22, which is designed to be inclined obliquely to the longitudinal direction 12 and forms an angle α therewith.

[0029] Furthermore, according to the invention, the instrument 2 comprises a shield 24 which faces the end section 10 of the handpiece 4 and is designed and arranged such that an annular gap 26 is formed between the shield 24 and the end section 10. The shield 24 is connected to the shaft 18 of the tool 6 in a rotationally fixed manner, in particular is formed integrally or is connected to the shaft. When the tool 6 is driven in rotation, the liquid which has penetrated into the annular gap 26 is set into a rotational movement according to the invention and is thereby expelled out of the annular gap 26 as a result of centripetal forces. As a result of centripetal forces acting on the rotating liquid, the liquid is therefore prevented from penetrating the tool receiving opening 14.If, when the instrument 2 is immersed in a liquid for a long time, liquid has penetrated into the annular gap and already into the tool receiving opening 14, this liquid is sucked from the handpiece 4 into the annular gap 26 within a few seconds when the tool is driven in rotation and is displaced from there radially outwards.

[0030] In the example shown, the shield 24 is cup-shaped and overlaps the end section 10 of the handpiece. The cup-shaped shield 24 comprises an inner side 28 which delimits the annular gap 26 from the outside and is inclined to the longitudinal direction 12, and in this case, for example, is inclined by the same angle a as the conical circumferential side 22 of the end section 10 of the handpiece 4 which extends into the shield 24.

[0031] Furthermore, the pot-shaped shield 24 comprises a pot base 30 which, in the case shown here as an example, runs essentially orthogonal to the longitudinal direction 12 and thus parallel to the end face 20 of the end section 10 and delimits a front-side region of the annular gap 26 between itself and the end face 20. Contours or structures on the inside of the shield 24 which deviate from this, in particular those which promote a radially outward displacement of liquid due to centrifugal force, are also conceivable. It is advantageous if the pot-shaped shield 24 sits on the shank 18 of the tool 6 in a liquid-tight manner in the circumferential direction. This can be achieved by the shield 24 being formed in one piece with the shank of the tool 6 (not shown here, but indicated in Figure 2) or by it being joined to the shank 18 of the tool 6 in a liquid-tight manner.For this purpose, the shield 24 has a central through-opening 32 with which the shield 24 can be plugged onto the shaft 18 of the tool 6 and can be fastened in a rotationally fixed manner, for example by means of a welded connection or in some other way.

[0032] Figures 2a and 2b illustrate the penetration of liquid into the annular gap 26 when the tool 6 is stationary (arrows pointing in the direction of the annular gap 26) and the displacement of liquid which has penetrated into the handpiece 4 and into the annular gap 26 radially outwards (arrows pointing out of the annular gap 26).

[0033] Figures 3a) to c) show a further embodiment of an instrument 2 according to the invention, in which the shield 24 is also cup-shaped and extends over the end section of the handpiece. However, the cup shape is more like a dome-shaped, curved shell both inside and out. Again, the shield 24 defines an annular gap 26 between itself and the end section 10 of the handpiece 4, from which any fluid that has penetrated is expelled when the tool 6 is driven in rotation.

[0034] Finally, Figures 4a ) to c ) show another

[0035] Embodiment of the invention in which the shield 24 is formed by a flange section 40 in the form of an annular disk 42 extending in a plane orthogonal to the longitudinal direction 12 of the instrument and tool 6. The flange section 40 forms a side 44 facing the end section of the handpiece 4 (not shown here), with which side the flange section 40 delimits an annular gap 26 between itself and the end section 10 of the handpiece 4. The flange section 40 has on its side 44 structures 48 forming displacement surfaces 46 which engage in the annular gap 26. When the tool and the shield 24 are driven in rotation, fluid is displaced radially outwards and thus expelled from the annular gap 26 between the shield 24 and the end section 10 of the handle part 4. In the exemplary case shown in Figure 4b, the structures 48 have spirally extending displacement surfaces 46. Figure 4c shows a further

[0036] Embodiment of structures 48 that are star-shaped, i.e., tapering radially outward. They also form displacement surfaces 46.

Claims

Patent claims 1. Surgical instrument (2), in particular for endoscopic applications, with a handpiece (4) and with a tool (6) which is detachably held in the handpiece and can be driven in rotation, in particular a milling tool, wherein the handpiece (4) has a front end section (10) which delimits a tool receiving opening (14) extending in a longitudinal direction (12), and wherein the tool (6) has a tool shank (18) which can be inserted into the tool receiving opening (14) of the handpiece in the longitudinal direction (12), characterized in that the tool (6) has a shield (24) facing the end section (10), which is designed and arranged such that an annular gap (26) is formed between the shield (24) and the end section (10), so that liquid located therein is also set in rotation when the tool (6) is driven in rotation and is thereby expelled outwards from the annular gap (26) as a result of centripetal forces.

2. Surgical instrument (2) according to claim 1, characterized in that the shield (24) is cup-shaped and overlaps the end portion (10) of the handpiece (4).

3. Surgical instrument (2) according to claim 1 or 2, characterized in that the shield (24) has an inner side (28) delimiting the annular gap (26) or an inner side region which is inclined to the Longitudinal direction (12) is inclined, in particular at least 5°, in particular at least 10°, in particular at least 15°, in particular at most 30°, in particular at most 25° to the longitudinal direction.

4. Surgical instrument (2) according to one or more of the preceding claims, characterized in that the end section (10) is tapered at the end face, in particular is conical or truncated cone-shaped or dome-shaped.

5. Surgical instrument (2) according to one or more of the preceding claims, characterized in that the end section (10) has an end face (20) extending in particular substantially orthogonal to the longitudinal direction and a peripheral side (22) and that the annular gap (26) extends from the end face (22) over the peripheral side.

6. Surgical instrument (2) according to one or more of the preceding claims, characterized in that the annular gap (26) extends inclined to the longitudinal direction (12) in the region of the peripheral side (22) of the end section (10).

7. Surgical instrument (2) according to one or more of the preceding claims, characterized in that the annular gap (26) has a gap width of at least 0.2 mm, in particular of at least 0.3 mm, in particular of at least 0.4 mm, in particular of at least 0.6 mm, in particular of at least 0.8 mm, in particular of at least 1.0 mm and further in particular of at most 8.0 mm, in particular of at most 6.0 mm, in particular at most 5.0 mm, in particular at most 4.0 mm, in particular at most 3.0 mm, in particular at most 2.0 mm.

8. Surgical instrument (2) according to one or more of the preceding claims, characterized in that the cup-shaped shield is rotationally symmetrical, i.e. concentric, at least internally.

9. Surgical instrument (2) according to one or more of the preceding claims, characterized in that the shield (24) is formed in one piece with the shaft (18) of the tool (6) or is fixed or can be fixed in a rotationally fixed manner and in any case non-detachably for the intended use on the shaft (18) of the tool, in particular by a welded connection, in particular a laser welded connection, or by another, in particular materially bonded connection, including an adhesive connection.

10. Surgical instrument (2) according to one or more of the preceding claims 1, 3-4, 7, 9, characterized in that the shield (24) is formed by a flange section (40) with a side (44) facing the end section (10) of the handpiece (4) and the tool receiving opening (14), and that on this side (44) of the flange section (40) structures are formed which assist the expulsion of fluid from the annular gap (26) when the tool (6) is driven in rotation.

11. Surgical instrument (2) according to claim 10, characterized in that the structures (48) extend radially or spirally Displacement laugh (46) or that the structures (48) taper radially outwards.

12. Surgical instrument (2) according to claim 10 or 11, characterized in that the structures (48) have a height in the longitudinal direction (12) of up to 0.5 mm and in particular of at least 0.5 mm, in particular of at least 0.8 mm, in particular of at least 1.0 mm and further in particular of at most 5.0 mm, in particular of at most 4.0 mm, in particular of at most 3.0 mm, in particular of at most 2.0 mm.

13. Surgical instrument (2) according to one or more of the preceding claims, characterized in that it is designed for a rotating drive of the tool with up to 30,000 revolutions / min, in particular with at least 30,000, in particular with at least 40,000, in particular with at least 50,000, in particular with at least 60,000 and in particular with at most 100,000, in particular with at most 90,000, in particular with at most 80,000 revolutions / min.

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