DE202009007979U1 - Surgical instrument - Google Patents

Abstract

A surgical instrument having a proximal and a distal end portion comprising an elongate hollow shaft extending from the proximal to the distal end portion, a hollow cylindrical drive member rotatably supported in the outer shaft, and a drive element disposed at the distal end portion of the instrument coupled cutting, abrasive or milling tool, wherein the drive element has a arranged between the proximal and distal end portion of the flexible portion comprising a plurality of ring segments having in the axial direction respectively a first and a second end portion, wherein the first end portion two or more protruding projections in the axial direction and the second end region comprises two or more recesses receiving the projections and the ring segments articulate on the projections and recesses, characterized in that the ring segments on the front and Rüc jumps in the axial and / or radial direction are positively connected to each other.

Description

The The invention relates to a surgical instrument for minimally invasive surgical interventions with one at a so-called distal End of a shaft coupled to a drive element tool. Such instruments are often called shavers.

surgical Instruments of this type have a proximal and a distal End section on, a long stretched hollow outer Shaft, a rotatably mounted in the outer shaft, hollow cylindrical drive element and one at the distal end portion the instrument arranged, coupled to the drive element Cutting, abrasive or milling tool.

Next rectilinear instruments are also surgical instruments known in which the distal end portion angled or cranked is also more difficult to access with the surgical instrument To be able to reach working positions and the work area of the instrument in general.

It is known in this context, the drive element between equipping the proximal and distal end sections with a flexible section, comprising a plurality of ring segments, which in the axial direction each having a first and a second end region, wherein the first end portion two or more projecting in the axial direction Projections and the second end region two or more the Includes projections receiving recesses and the ring segments over the projections and recesses articulate.

Surgical instruments of this kind are for example from the EP 0 677 276 B1 known, wherein the flexible portion allows to transmit the torque from the proximal end portion of the drive element effectively to the distal end portion and thus to the tool connected there.

adversely in these known instruments is that the production, in particular the assembly of the flexible section is expensive because the flexible section of a variety of ring segments only is loosely assembled so that not only in manufacture, but also at a later disassembly of the drive element and its removal from the hollow cylindrical outer shaft, Ring segments can be lost, especially in the OP.

There the shaver typically removes body tissue serves, which is located inside the shaft and the drive element existing channel used to aspirate the removed tissue parts.

Another shaver that follows this principle of the construction of the drive element with loosely interlocking ring segments in the flexible section, is from the DE 10 2004 046 539 A1 known.

Another starting point was in the EP 0 986 989 B1 chosen in which the flexible portion is formed by a hollow cylindrical member whose wall is slotted helically in the radial direction, alternating meandering alternating teeth and indentations along the helix and interlock, so that in the axial direction cohesion of the turns is given.

adversely with this solution is a considerably lower flexibility and frequent fatigue fractures, which occur due to the alternating bending stress when rotating the shaft. An oscillating drive should be possible with this instrument However, it is with high speeds only in one direction drivable.

task The invention is a surgical instrument of the beginning described type so that with minimal effort in the production of safe operation, especially at high Speeds is possible.

These Task is according to the invention in a surgical Instrument solved by the ring segments over the projections and recesses in the axial and / or radial direction are positively connected with each other.

By the positive locking of the projections and recesses in axial and / or radial direction, preferably in the axial and radial directions, becomes the handling of the drive element during manufacture, during assembly and considerably facilitated in a later disassembly. The articulated connection of the ring segments in the flexible section is still guaranteed.

Of the Positive locking in the axial or radial direction reduces considerably Scope the risk of losing individual ring segments when the loss not by the preferred axially and radially given positive locking excluded from the outset.

about the positive connection in the axial and / or radial direction can also mutual positioning of the adjacent ring segments be specified so precisely that high speeds in both possible drive directions can be realized.

typically, the projections and recesses are in regular Distances in the circumferential direction of the respective ring segment arranged. This ensures a uniform Loading the ring segments in the transmission of the driving forces and thus the largest possible service life.

According to one Embodiment of the present invention is the number the projections and returns odd chosen, resulting in particular in an arrangement of the Projections and recesses in regular Distances in the circumferential direction of the respective ring segment a positive connection in the radial direction without further action results.

additionally or alternatively, the positive connection in the radial direction can be achieved be that the protrusions on their radially outside lying side in the circumferential direction a larger Have expansion than on its radially inner side and that the recesses correspond on their radial inner side have an extent in the circumferential direction, which is smaller than the corresponding radially outer Expansion in the corresponding area of the return engaging projection.

With This measure can be a positive connection in the radial direction irrespective of whether the number of and returns is odd or even.

Of the Positive locking in the axial direction can be achieved in that the projections on their side facing away from the ring segment, free End a greater extent in the circumferential direction have as at their end adjacent to the ring segment and the Recesses at its open end a smaller one Extend in the circumferential direction than the extent of in the recess engaging protrusion at its free End in the circumferential direction.

Becomes a form fit both in the axial direction and in the radial direction realized, you have a drive element present, as a whole can be handled without the risk that individual parts of the lost flexible section.

Preferably is such a drive element with a flexible section so made that initially a one-piece hollow cylindrical element is used, for example, with laser contours of the Protrusions and recesses are cut. Often The resulting cutting gap already sufficient to a sufficient pivoting ensure the individual ring segments against each other, so the flexible portion of the drive element one for the each application can provide sufficient bending angle.

is in the axial direction already has a positive fit, so can the Form fit in the radial direction can also be achieved by that the projections in the axial direction on the radially outside lying side have a greater extent in the longitudinal direction as on the radially inner side and the recesses on the radially inner side a depth in the axial direction which is smaller than the length of the projections in the axial direction on the outer side.

A preferred form of the projections in the circumferential direction is the Trapezoidal shape, although of course deviating from it Molds allow the realization of a positive connection in the axial direction. Corresponding to this are the returns in Circumferential direction preferably trapezoidal.

For the assurance of a positive connection in the radial direction are the Projections preferably with one in the radial direction formed trapezoidal cross-section, wherein here the vaults on the radially outer and radially inner surface of the projections disregarded in this definition.

corresponding For this purpose, the recesses in the radial direction also preferably a trapezoidal cross-section on.

These and further advantages of the invention are described below with reference to the Drawing explained in more detail. They show in detail:

1 a perspective view of a surgical instrument according to the invention in the form of a shaver;

2 an enlarged portion of the Shaver 1 ;

3 an alternative embodiment of the distal end of 2 ;

4 a detail of the flexible drive element;

5 an alternative embodiment of a part of the flexible drive element; and

6 a schematic representation of the nature of the use of the surgical instrument according to the invention.

1 shows a total with the reference numeral 10 designated surgical instrument according to the present invention, which follows which is also called Shaver for short.

The shaver according to the invention 10 points at its proximal end 12 a coupling device 14 which can be connected to a surgical drive (not shown).

On the distal side closes to the coupling device 14 a bending and torsion resistant shaft 16 in the region of its distal end portion 18 about 20 ° with respect to the longitudinal axis of the Shaver 10 is inclined and a distal shaft portion 20 includes.

The coupling device 14 is already in the DE 10 2004 046 539 A1 shown and described in detail, so that this description can be made there because of the details.

The shaft 16 with its distal end portion 20 is as an elongated outer sleeve 22 in which a hollow cylindrical drive element 24 is guided, trained. The shaft 16 or the sleeve 22 is closed at the distal end and with a side opening 26 provided, which has a passage from the interior of the sleeve 22 to the environment of the Shaver 10 creates.

To the drive element 24 is at its distal end 28 a tool 38 coupled, which also has a side opening 30 which corresponds substantially to the lateral opening 26 the sleeve 22 is trained. The openings 26 and 30 are how out 2 visible, sanded at their edges and provided with cutting. Will the drive element 24 set in rotation, so are in the range of the lateral openings 26 . 30 passing pieces of tissue through the cutting of the edges of the openings 26 . 30 separated and can over the drive in the element 24 remaining interior are sucked by means of negative pressure.

In the end section 18 of the Shaver 10 goes the hollow cylindrical drive element 24 from a solid hollow cylindrical part into a hollow cylindrical flexible section 32 over, that of a number of ring segments 34 is formed in the following with reference to the 4 and 5 to be described in more detail.

The distal end of the drive element 24 ends with a coupling piece 36 , to the loosely engaging a tool, in particular the milling tool 38 , can be docked.

3 again shows the distal end 20 of the Shaver 10 in an alternative embodiment, in which instead of via a coupling piece 36 coupled tool 38 a tool 40 captive held in positive engagement.

Differences arise in these two embodiments in the manufacture of instruments:
In the embodiment of the 2 becomes the tool when assembling 38 in the sleeve 22 introduced, in which case the distal end portion is bent and brought into its final shape. After that, the drive element can be 24 with its flexible section 32 Insert in this sleeve, the coupling piece 36 in the proximal end of the tool 38 intervenes.

In the embodiment of the 3 in contrast, the drive element 24 hanging together with the tool 40 made and in the sleeve 22 inserted, as long as this still has a straight shape. Only then will the sleeve 22 bent and brought into their final, bent form.

The ring segments 34 are in 4 shown in detail and have a first end 46 in a first axial direction and a second end region 48 in the opposite axial direction. At its first end region, the ring segment 34 six projections 50 on, regularly distributed in the circumferential direction of the ring segment 34 are arranged. At its axially opposite end portion 48 has the ring segment 34 , corresponding to the projections 50 shaped recesses 52 , wherein the projections and recesses in the circumferential direction, each having a trapezoidal shape, wherein the projections 50 the axially free end of the projections 50 has a greater extent in the circumferential direction than the adjacent end of the ring segment, while corresponding to the recesses 52 have at their inner end a greater extent in the circumferential direction than that in the direction of the end region 48 lying outwardly open sections. In the case of ring segments 34 , in the 4 are shown in detail, both end region are provided with an identical except for the mirror image arrangement configuration due to the regular geometry.

Because of projections 50 in correspondingly shaped recesses 52 with play and still engage positively, an axial positive fit is given, so that the ring segments 34 connected together in the axial direction and so together in the outer sleeve 22 introduced or can be pulled out of this.

Nevertheless, due to the existing gap between the protrusions 50 and the returns 52 sufficient clearance for a hinged connection of adjacent ring segments 34 to ensure.

To the drive element 24 with its flexible section 32 and the ring segments forming this 34 to handle a total of problems, it is provided that the extension of the projections 50 at its free end in the circumferential direction (a) is greater than the corresponding extent on the inside. (A ').

The recesses are corresponding 52 dimensioned at its outer and inner circumference with a width b and a width b ', which also allow a positive fit in the radial direction, so that the ring segments 34 Captive connected and manageable.

While in the ring segments of 4 each six projections and six recesses are provided are in an alternative embodiment of the ring segments 60 in 5 showing the simplest embodiment, only two projections each 62 and two returns 64 at the axially opposite ends of the ring segment 60 however, which may similarly be used in the practice of the present invention. Only the feasible swing angle of two adjacent ring segments 60 is opposite to two adjoining ring segments 34 a bit limited.

Again, the pros and returns 62 . 64 should be positively connected to each other in the axial and / or radial direction, so that the comments on 4 concerning the configuration of the projections 50 or the recesses 52 Reference can be made.

The sectional views of the 5b to 5e illustrate the trapezoidal cross-sections of the projections 62 and the returns 64 in the circumferential as well as in the axial direction. This also applies to the formation of the projections and recesses of the ring segment 34 ,

In the overview figure 6 Finally, it indicates the importance of the angled area in the distal end section 18 of the shaft 16 for the achievable with the shaver work area, by the angulation as in 6 shown significantly larger fails than a straight guided only shaft.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0677276 B1 [0005]
• DE 102004046539 A1 [0008, 0037]
• - EP 0986989 B1 [0009]

Claims (10)

A surgical instrument having a proximal and a distal end portion comprising an elongate hollow shaft extending from the proximal to the distal end portion, a hollow cylindrical drive member rotatably supported in the outer shaft, and a drive element disposed at the distal end portion of the instrument coupled cutting, abrasive or milling tool, wherein the drive element has a arranged between the proximal and distal end portion of the flexible portion comprising a plurality of ring segments having in the axial direction respectively a first and a second end portion, wherein the first end portion two or more protruding projections in the axial direction and the second end region comprises two or more projections receiving recesses and the ring segments via the projections and recesses articulated engage each other, characterized in that the ring segments on the front and Rü jumps in the axial and / or radial direction are positively connected to each other. Instrument according to claim 1, characterized that the projections and recesses in regular Distances in the circumferential direction of the respective ring segment are arranged. Instrument according to claim 1 or 2, characterized that the number of protrusions and recesses is odd. Instrument according to one of claims 1 to 3, characterized in that the projections on their radially outer side in the circumferential direction a larger Have expansion than on its radially inner side and that the recesses are on the radially inside lying side in the circumferential direction have an extension, the smaller than the corresponding radially outside Extension of the protrusion engaging in the recess. Instrument according to one of claims 1 to 4, characterized in that the projections on their the ring segment facing away from the free end in the circumferential direction greater extent than adjacent to Ring segment and that the recesses at her open end have a smaller extent in the circumferential direction as the extent of the protrusion engaging in the recess at its free end. Instrument according to one of claims 1 to 5, characterized in that the projections in the axial direction on the radially outer side of a larger Have expansion than on the radially inner side and that the recesses on the radially inner Side have a depth in the axial direction, which is less than the length of the projections in the axial direction its outer side. Instrument according to one of claims 1 to 6, characterized in that the projections in the circumferential direction Trapezoidal are formed. Instrument according to one of claims 1 to 7, characterized in that the recesses are trapezoidal in the circumferential direction. Instrument according to one of claims 1 to 8, characterized in that the projections in the radial direction have a trapezoidal cross-section. Instrument according to one of claims 1 to 9, characterized in that the recesses in the radial direction have a trapezoidal cross-section.