WO2014067804A1

WO2014067804A1 - Endoscopic instrument

Info

Publication number: WO2014067804A1
Application number: PCT/EP2013/071959
Authority: WO
Inventors: Stephan Prestel; Eberhard Körner
Original assignee: Richard Wolf Gmbh
Priority date: 2012-10-30
Filing date: 2013-10-21
Publication date: 2014-05-08
Also published as: DE102012219881A1; DE102012219881B4

Abstract

The invention relates to an endoscopic instrument comprising a shaft with an instrument head that is arranged at the distal shaft end and carries a tool comprising two jaw parts (21, 22) able to be pivoted relative to one another. Said instrument head can be pivoted about an axis transverse to the longitudinal direction of the shaft, the pivoting motion of said instrument head and that of the jaw parts (21, 22) being able to be controlled from the proximal instrument end by means of tensile means (2-4) guided in the shaft. The tensile means (2-4) for the pivoting motion of the jaw parts (21, 22) are guided across rollers that are rotatably mounted about the axis (10) about which said instrument head (5) can be pivoted. The tensile means are arranged around the rollers such that they fully enclose the periphery of the roller in question when the instrument is in its extension position. In the installation position, one jaw part (22) comprises outer discs (24) and one jaw part (21) comprises inner discs (23) lying therebetween, the inner discs (23) being larger in diameter than the outer discs (24).

Description

Endoscopic instrument

description

The invention relates to an endoscopic instrument having the features specified in the preamble of claim 1.

Such endoscopic instruments typically have an elongated shaft and an instrument head arranged at the distal shaft end, which carries a tool with two jaw parts which can be pivoted relative to one another. The instrument head is pivotable about an axis transversely to the longitudinal direction of the shaft, wherein the pivotal movement of the instrument head and the pivoting movement of the jaw parts can be controlled via the traction means guided in the shaft from the proximal end of the instrument. For this purpose, either a corresponding handle is provided at the proximal end of the instrument, which allows a direct control by the surgeon or it is provided at the proximal end of a connection part, which allows the electromotive control of the individual functions, as in robotic surgery systems of the prior art. In this context, reference is made, by way of example only, to US Pat. No. 6,312,435 Bl, where such a system is shown, which carries and controls a generic endoscopic instrument.

In such instruments one always strives to keep the diameter of the instrument as small as possible and on the other hand to be able to move the tool at the distal end of the instrument with as many degrees of freedom as possible. In the state of the art, traction means in the form of cable pulls have proved successful, which on the one hand can be guided over long distances in a small space, and on the other hand pivoting motion conditions with comparatively large angles. In addition, cables in such instruments have the advantage that a blockage of the instrument within the mechanism is practically impossible, so that the instruments can be safely pulled out of the body opening even in case of defects.

The construction known from US Pat. No. 6,371, 952 B2 represents a compromise of the smallest possible shaft diameter and the largest possible cable pulley diameter and, moreover, is structurally complex.

A generic instrument is known from US 201 1/0106145 AI.

Based on this prior art, the invention has the object, a generic endoscopic instrument in such a way that on the one hand as slim as possible outer contour of the distal instrument part and the shaft is achieved and on the other hand given a high level of functionality. Finally, a cost-effective production and assembly should be possible. In addition, the distal bending should be possible on both sides by at least 90 ° with high rigidity of the instrument in two directions.

This object is achieved according to the invention by an endoscopic instrument having the features specified in claim 1. Advantageous embodiments of the invention are specified in the subclaims, the following description and the drawing.

The endoscopic instrument according to the invention has an elongate shaft with an instrument head arranged on the distal shaft end, which carries a tool with two jaw parts which can be pivoted relative to one another. The instrument head is pivotable about an axis transverse to the longitudinal direction of the shaft, typically transversely to the central axis of the shaft, wherein the pivoting movement of the instrument head and the jaw parts guided in the shaft traction means of proximal end of the instrument is controllable. The traction means for controlling the pivoting movement of the jaw members are guided by rollers which are mounted rotatably about the axis about which the instrument head is pivotable, wherein a traction means comprises a roller in the extended position of the instrument in full. According to the invention, a jaw part in the installed position has outer discs and a jaw member in the installed position therebetween and inner discs, wherein the inner discs have a larger diameter than the outer discs.

The traction means, which are provided for controlling the pivoting movement of the jaw parts, are guided in the region of the joint, with which the instrument head is mounted on the distal shaft end, via rollers which are freely rotatably mounted about the hinge axis, wherein the traction means are guided so that a role is advantageously provided for each traction means and the traction means comprises the associated role fully, d. H. in the neutral position of the instrument, which is typically the elongated position, wraps around 360 °. Depending on the pivoting movement of the head relative to the shaft, the wrap angle varies and, depending on the pivoting direction, is approximately 360 ° plus / minus the swivel angle. Usually, the neutral position of the instrument is the elongated position, d. H. out of this neutral position, the instrument head can be pivoted about the pivot axis to each side by at least 90 ° relative to the instrument shaft, resulting in corresponding wrap around the rollers of 270 ° - 450 °.

If the neutral position of the instrument, which is conceivable, not the elongated position, but for example, the head is already angled in the neutral position by 15 ° relative to the longitudinal axis of the shaft, the wrap is in this case, either 375 ° or 345 ° and be increased or decreased by the swing angle from this neutral position. The particular advantage of this large wrap angle is that each traction device must be performed only on a role and thus on the one hand a good power transmission is given to the jaws and on the other hand, a compact design is possible.

According to the invention, each jaw part has a disk arranged externally in the installed position and a disk arranged inside in the installation position, the traction means acting in the opening direction and the disk arranged internally acting in the closing direction according to an advantageous development of the invention Traction means is guided. In this case, the internally arranged disc according to the invention has a larger diameter than the externally arranged disc, whereby higher closing forces in the closing direction than in the opening direction with a comparatively small instrument diameter can be realized.

A corresponding arrangement is advantageously carried out in the region of the joint between the shaft end and the instrument head by the larger diameter rollers between the smaller diameter rollers are arranged so as to optimally use the typically circular in cross-sectional shape.

Advantageously, the pivot axis of the instrument head is arranged transversely and at a distance from the preferably common pivot axis of the jaw parts. With such an arrangement, it is possible if the jaw parts, which is suitably the case, are provided in the opening and closing direction with a separate traction means, a pivotal movement of the tool, so the jaw pair to realize about the pivot axis of the jaws. This is particularly useful with motor-controlled traction means, since depending on the control of the traction means the jaws can not only be opened and closed to each other, but also in the respective opening or closing Position can be pivoted about the axis. An energetically operated, in particular electromotive control is particularly useful for the present invention, since it can also be compensated for the movement of the jaws, by the pivoting movement of the instrument head in the inventive arrangement due to the changing angle of wrap around the rollers and thus changing free Zugmittelängen done. Advantageously, according to an embodiment of the invention, the instrument head on a joint piece, which has at least one proximally directed projection on which the rollers for the traction means are rotatably mounted on a rotatably connected to the joint shaft, wherein on the shaft a disc is arranged rotationally fixed, at which the traction means are fixed for controlling the pivoting movement of the instrument head. The axis of rotation of this shaft thus also forms the pivot axis of the instrument head and the axis of rotation for the rollers. It is particularly simple in construction if two legs pointing proximally are provided on the joint piece, between which the rollers for the traction means are rotatably arranged on the shaft and between which the disk is preferably arranged centrally for fixing the traction means. The arrangement of two legs is structurally simple and forms a stable construction.

Advantageously, the distal shaft end has at least one distally directed projection on which the joint piece is pivotally mounted. It is structurally simpler and more favorable, instead of a single projection, to provide two distally directed legs on the distal shaft end, between which the joint piece is received and in which the shaft of the joint piece is rotatably mounted. These legs can, for example, by appropriate cutouts be formed of a reinforced hollow cylindrical end portion of the shaft.

The joint piece itself advantageously has at least one distally downward directed projection on which the jaw parts are rotatably mounted. It is structurally advantageous to provide instead of a single projection two distally directed legs on the joint piece, between which the jaws are rotatably mounted and preferably arranged relative to the longitudinal axis offset by 90 ° to the distally directed legs on the shaft end or the pivot axis of the instrument head are. Such an arrangement is advantageous because it can be used to realize a pivotal movement of the jaw parts in virtually any direction to the shaft axis. According to the invention, two discs are arranged on each jaw part, on each of which a traction means is fixed and whose main extension extends transversely to the axis of rotation of the jaw part. These discs serve as a guide for the traction means and ensure that the traction means are guided with sufficient lever arms around the pivot axes, and that over as large a pivoting range. This can be achieved if, for each jaw part, two discs, ie for each traction means, a separate disc is provided. If what is advantageous according to the invention, the traction means are fixed to the end of the discs, so comparatively high forces can be applied to the jaw parts, in both pivot directions. By varying the diameter of the discs beyond a different power development can be realized in the closing direction and opening direction. If, as with pliers, for example, the maximum force is to take place in the closing direction, the diameter-large discs near the central axis of the instrument (in extended position) can be arranged, whereas the discs for guiding the traction means, which are effective in the opening direction of the jaws , can be further out, where the space is less. The embodiment of the invention makes it possible, with a suitable design of the jaw parts, to form them from the same components, as a result of which the number of parts is reduced. In particular, the jaw parts can then be inexpensively produced as injection-molded components, cast steel components or by other shaping methods.

The invention is explained in more detail with reference to an embodiment shown in the drawing. It shows:

1 is a simplified schematic perspective view of the distal end of an endoscopic instrument according to the invention, Fig. 2 is the illustration of Figure 1 without the shaft end.

3 shows the representation according to FIG. 2 without a joint piece, FIG.

4 shows an enlarged view of the instrument head with distal connection to the shaft from another direction,

5 shows the control means for the upper jaw part in FIG. 3,

6 shows the control means for the lower jaw part in FIG. 3,

Hg. 7 in an enlarged perspective view of a jaw part,

Fig. 8 is a side view of the central disc for controlling the pivotal movement of the instrument head, and

9 is a view rotated by 90 ° according to FIG. 8. The endoscopic instrument illustrated with reference to the figures has an elongate shaft 1, of which only the distal end is shown in FIG. Within this shaft 1 cables 2, 3 and 4 are circumferentially guided, which are provided to control the described below instrument head 5 with the tools 6 located thereon in the form of a pair of pliers. These cables 2 - 4 extend over the entire length of the shaft to the proximal end of the instrument, where they are guided depending on the design of the instrument either in a handle with which the surgeon can hold and control the instrument or in a proximal receiving device, the is provided and designed for connection to a robot-like system, in which the cables 2 - 4 are connected to electric motors. A connection provided for a robotic system is known, for example, from US Pat. No. 6,312,435 B1, to which reference is made in this respect by way of example.

The cables 2 - 4 are drawn circumferentially in the figures on the proximal side, alternatively they can not end circumferentially, d. H. be provided as six individual cables 2 a and 2 b, 3 a and 3 b and 4 a and 4 b, as indicated in the figures accordingly.

The cable pair consisting of the individual cables 2 a and 2 b is guided on the proximal side around a circular disc 7 and fixed there at the end, as shown in detail with reference to FIGS. 8 and 9. The disc 7 is circular and has on its outer circumference on a circumferential groove in which the cables 2 a and 2 b are performed, each ending in a lateral groove 8 a and 8 b and are fixed there by means of bolts 9 positively. Thus, by applying a proximally directed tensile force on the cable 2 a, the disc 7 in Fig. 8 in the clockwise direction and by applying a tensile force on the cable 2 b are rotated counterclockwise. These traction means 2 and 2 a and 2 b in conjunction with the disc 7, to which they are fixed, serve to pivot the instrument head fifth relative to the instrument shaft 1 about a pivot axis 10, which is perpendicular to the longitudinal direction of the shaft 1, here perpendicular to the longitudinal central axis 1 1 of the shaft 1 is arranged. The disc 7 is rotatably mounted on a shaft 12 which is rotatably mounted in bearings 13 which are received in legs 14 at the distal end of the shaft. These legs 14 are formed by corresponding cutouts in the shaft end and offset by 180 ° with respect to the longitudinal axis 11.

Rotationally fixed on the shaft 12 are two proximally directed legs 15 of a joint piece 16, which has a substantially the circular cross-section of the instrument head 5-filling base body 17, of which two offset by 180 ° arranged proximally directed leg 15 and two more distal - ward and also offset by 180 ° to each other arranged legs 18 extend, which, relative to the longitudinal center axis 1 1 of the instrument head, offset by 90 ° to the legs 15 are arranged. Since the disc 7 is rotatably connected via the shaft 12 and the legs 15 with the hinge piece 16, the hinge piece 16 and thus the entire instrument head 5 rotates with the disc 7, when this about the axis 10 by the cable 2 a in one or by the cable 2 b is rotated in the other direction. In this way, the instrument head can be pivoted about the axis 10 by at least 90 ° to both directions from the extended position shown in Fig. 1.

Between the proximally directed legs 15 of the joint piece 1 6, two pairs of rollers are freely rotatably mounted on the shaft 12, namely a pair of rollers 19 of comparatively small diameter and a pair of rollers 20 of larger diameter. The rollers 19 of smaller diameter sit further out on the shaft 12 than the rollers 20 of larger diameter. The rollers 20 thus each sit between the centrally arranged on the shaft 12 disc 7 and a small roller 19, which sits adjacent to a leg 15. The rollers 19 and 20 serve to guide and deflect the traction means which control the tool 6. The cables 3 a and 3 b are guided over the large rollers 20 and the cables 4 a and 4 b on the small rollers 19, in such a way that they in the extended position of the instrument (Fig. 1), the rollers 19, 20th wrap around 360 °. Depending on the pivot position of the instrument head 5 with respect to the shaft 1, the wrap angle may be greater or less, ie greater than or less than 360 ° by the angle of the pivot position to the extended position. Depending on the direction in which the instrument head 5 is pivoted relative to the shaft 1 by, for example, 90 °, the angle of wrap about the rollers 19 and 20 is 270 ° or 450 °.

Within the legs 18 directed distally, two jaw parts forming the tool 6 are pivotally mounted, namely a jaw part 21 in FIG. 1 and a jaw part 22 in FIG. 1. These jaw parts 21 and 22 are designed in their tool-side area in that they form a forceps jaw. They each have two discs 23 and 24, which are provided for the circumferential guidance and lateral fixing of the ends of the cables 3 a and 3 b and 4 a and 4 b. These discs 23 and 24 are integrally formed with the jaws 21 and 22, wherein the discs 24 are arranged at a distance from each other, while the discs 23 of the lower jaw part 21 form part of a cylindrical body and are arranged in the installed position between the discs 24. The discs 23 and 24 also have a lateral groove in which the respective cable end is fixed by means of a bolt, as shown in detail with reference to FIG. 8 in the case of the disk 7. The jaws 21 and 22 sit freely rotatable with their discs 23 and 24 on an axis 25 between the legs 18 of the joint piece 1 6. The axis 25 is received in the legs 18 of the joint piece 16. The discs 23 of the lower jaw part 21 have a larger one Accordingly, the rollers 19 have a smaller diameter than the rollers 20, wherein the small rollers 19 which guide the cables 4 a and 4 b, the larger discs 23 are assigned and the larger rollers 20th , which guide the cables 3 a and 3 b, the smaller discs 24 are assigned. This arrangement, which can be seen in its entirety, in particular from FIG. 4, optimally utilizes the typically circular cross-section of the instrument, ie the small rollers or discs are arranged farther outward than the large ones, ie where the latter, relative to the longitudinal central axis of the instrument in the circular cross-section remaining space is smaller. In this way, an endoscopic instrument can be created which has a very small diameter, not only in the shaft, but also in the head area. The instrument can, as the above description illustrates, be constructed with only a few simple components and has on the one hand a high mobility of the tool and on the other hand a high stability. Due to the arrangement of the pivot axes 10 and 26, which are offset relative to the longitudinal central axis 1 1 offset by 90 ° to each other, a two-way pivoting movable tool 6 is also provided, which can reach the area in front and adjacent.

Since the jaw parts 21 and 22 are pivotable independently of each other in the opening and closing direction, a pivoting of the entire tool 6 is given about the axis of rotation 26, which in particular in connection with a robotic control is feasible. The jaws 21 and 22 can also be pivoted from the elongated position shown in Fig. 1 by at least 90 ° to both directions. LIST OF REFERENCE NUMBERS

1 - shaft

2 - cable for head swing

2 a, 2 b - Cable

3 - Cable for in Fig. 1 upper mouth arrow

3a, 3, b - cable

4 - Cable for in Fig. 1 lower mouth arrow

4 a, 4 b - Cable

5 - instrument head

6 - Tool

7 - disc

8 a - Nuf for cable 2 a

8 b - Nuf for cable 2 b

9 - bolts

10 - pivot axis

1 1 - Längsmiftelachse of the shaft

and instrument in stretched position

12 - wave

13 - warehouse of 12

14 - thighs

15 - proximal thighs of the joint

1 6 - Joint piece

1 7 - basic body of 16

18 - disfalward legs of 16

19 - small roles

20 - big rolls

21 - in Fig. 1 lower jaw part

22 - in Fig. 1 upper jaw part

23 - slices of 21

24 - slices of 22

25 - axle bolts

26 - axis

Claims

Expectations

Endoscopic instrument with a shaft (1) and with an instrument head (5) arranged at the distal end of the shaft, which has a tool (6) with two jaw parts (21, 22) that can be pivoted towards one another, the instrument head (5) rotating about an axis (10). can be pivoted transversely to the longitudinal direction of the shaft (1) and the pivoting movement of the instrument head (5) and that of the jaw parts (21, 22) can be controlled from the proximal end of the instrument via traction means (2 - 4) guided in the shaft (1), the traction means (3, 4) for the pivoting movement of the jaw parts (21, 22) are guided via rollers (19, 20) which are rotatably mounted about the axis (10) about which the instrument head (5) can be pivoted, a traction means ( 3a,

3 b, 4 a, 4 b) completely encompasses a roller (19, 20) in the extended position (Fig. 1) of the instrument, characterized in that a jaw part (22) in the installed position has external disks (24) and a jaw part (21 ) in the installed position has intermediate and inner disks (23), the inner disks (23) having a larger diameter than the outer disks (24).

Instrument according to claim 1, characterized in that the pivot axis (10) of the instrument head (5) is arranged at a distance and transversely to the preferably common pivot axis (26) of the jaw parts (21, 22).

Instrument according to claim 1 or 2, characterized in that the instrument head (5) has a joint piece (16) which has at least one proximally directed projection (15) on which the rollers (19, 20) for the traction means (3, 4 ) are rotatably arranged on a shaft (12) connected in a rotationally fixed manner, which has a disk (7) fixed thereon, on which the traction means (2a, 2b) are fixed for controlling the pivoting movement of the instrument head (5).

4. Instrument according to claim 3, characterized in that the joint piece (16) has two proximally directed legs (15), between which the rollers (19, 20) for the traction means (3 a, 3 b,

4 a, 4 b) are rotatably arranged on the shaft (12) and between which the disk (7) for fixing the traction means (2 a, 2 b) for controlling the pivoting movement of the instrument body (5) is arranged in the middle.

5. Instrument according to one of the preceding claims, characterized in that the distal shaft end has at least one distally directed projection (14) to which the joint piece (16) is pivotally attached.

6. Instrument according to one of the preceding claims, characterized in that the distal shaft end has two distally directed legs (14), between which the joint piece 16) is received and in which the shaft (7) of the joint piece (16) is rotatably mounted.

7. Instrument according to one of the preceding claims, characterized in that the joint piece (16) has at least one distally directed projection (18) on which the jaw parts (21, 22) are rotatably mounted.

8. Instrument according to one of the preceding claims, characterized in that the joint piece (1 6) has two distally directed legs (18), between which the jaw parts (21, 22) are rotatably mounted and which are preferably relative to the Longitudinal axis (1 1) are arranged offset by 90 ° to the proximally directed legs (15).

Instrument according to one of the preceding claims, characterized in that each jaw part (21, 22) has two disks (23, 24) on which a traction means (3 a, 3 b, 4 a, 4 b) is guided and fixed and their Main extension runs transversely to the axis of rotation (26) of the jaw part (21, 22).

Instrument according to one of the preceding claims, characterized in that the traction means (3 a, 3 b), which are guided around the smaller diameter disks (24), are guided around rollers (20) whose diameter is larger than the diameter of the Rollers (19) around which the traction means (4a, 4b) are guided, which are guided around the larger diameter disks (23).

Instrument according to one of the preceding claims, characterized

characterized in that the larger diameter rollers (20) are arranged between the smaller diameter rollers (19).