DE102016003175A1 - Gynecological or urological endoscope - Google Patents

Abstract

A gynecological or urological endoscope (1) with a shaft tube (3) whose cross-section has an elongate inner contour which has in a first contour region a first circular arc (5) with a first radius (r ') and in a second contour region a second circular arc ( 6) with a second radius (r), which is greater than the first radius (r '), which circular arcs (5, 6) with their centers (M, M') at a distance from the sum of their radii (r, r ' ) and on both sides of the through the centers (M, M ') extending symmetry axis (S) of the inner contour by tangential contour regions (7) are connected, each tangentially in the circular arcs (5, 6) pass over at their ends, wherein in the second circular arc (6) is arranged in an optical tube formed optics (8) which is secured with a holder (4) against displacement in the direction of the first circular arc (5), characterized in that the holder on the shaft tube (3) at least one after i formed recess (4) which is disposed on one of the tangential contour regions (7) adjacent to the transition to the second circular arc (6).

Description

The invention relates to an endoscope referred to in the preamble of claim 1 Art.

A generic endoscope is in the DE 8 416 392 U described. It is an endoscope for working in the ureter or through the ureter in the kidney.

In this case, the shaft is formed with elongated cross-section and may comprise two elongated partial areas of circular cross-section, of which a larger space for receiving an optic is formed and the smaller than working channel for receiving a working instrument such as a biopsy forceps or an instrument stone removal. Remaining remaining spaces in the cross section can be used as a flushing channel.

Please note the very cramped spatial conditions. Hysteroscopes are gynecological endoscopes that are inserted into the uterus through the very narrow and sensitive cervical canal. Ureteroscopes are urological endoscopes that are inserted through the very narrow ureter, which is very limited in stretchability. Therefore, in the case of generic endoscopes, in particular the outer circumference of the shaft must be kept as small as possible. This leads to the elongated cross-sectional shape of an inner contour shown in the cited document with circular arcs at the ends and adjacent tangents.

The cited known construction is particularly advantageous because it solves an additional problem, namely the mounting of the optics in the shaft tube. In previous designs, the shaft tube contained only the optics and the instrument. These were freely arranged and could move, for example, with vibrations in the shaft tube. This can cause the instrument to come into contact with the optics, which hinders the precise handling of the instrument.

The cited construction used as a holder for securing the position of the optics in the shaft tube mounted inner tube, which either surrounds the space for the instrument or the space for the optics and thus separates these spaces from each other, so that unwanted contact safely prevented.

However, arranged in the interior of the shaft tube inner tube has the disadvantage that it reduces the interior space. Even with very small wall thickness of the inner tube results in cross-sectional losses that are not tolerable given the very critical in the generic endoscope space. They would have to be absorbed by cross-sectional reduction of the optics or the working instrument or go to the detriment of the flushing channel. So you're faced with a constructive dilemma.

The object of the present invention is to solve the described problem.

This object is achieved with the features of the characterizing part of claim 1.

According to the invention, the holder is formed in the form of an inwardly formed recess on the shaft tube. This depression is located at the end of one of the tangents before the transition to the larger circular arc, ie where the optics sits. The recess locks the optics thus in a movement in the direction of the instrument. The optics are therefore prevented in the desired manner against movements in the direction of the instrument.

Essentially the same result as with the cited known construction results with the invention. With the invention, however, no inner tube is required and the consequent loss of cross-section is avoided.

A recess according to the invention may be punctiform. Preferably, however, it is formed according to claim 2 as a bead which extends parallel to the shaft tube. This results in a more precise storage of the optics.

A serving for holding recess only on a tangent already sufficient for the intended mounting purposes. However, the advantageous two-sided mounting according to claim 3 is better and more precise.

The cross section of the shaft tube could be designed differently over the length. Preferably, however, according to claim 4 whose inner contour is constant over the length of the shaft tube. This results in a simpler construction and lower impairments of the available cross-section.

Advantageously according to claim 5, the wall thickness is constant. This ensures an uncomplicated construction and small external dimensions.

Claim 6 lists the types of endoscopes in which the invention can be used advantageously. In gynecology these are the hysteroscope for working in the uterus through the very narrow and pain-sensitive cervical canal, in urology the cystoscope for working in the bladder, the ureteroscope for working beyond the bladder in the very narrow ureter and the nephroscope to work beyond the ureter in the kidney.

The claim 7 contains advantageous dimensions for endoscopes according to the invention.

In the drawing, the invention is shown for example and schematically on a hysteroscope. Show it:

1 a side view of a hysteroscope according to the invention,

2 an enlarged section along line 2-2 in 1 and

3 the representation of 2 in schematic form and

4 - 7 highly schematic cross-sections of a hysteroscope with the associated flow rates.

1 shows the side view of a hysteroscope 1 largely conventional construction with a distal direction of a main body 2 outgoing shaft tube 3 , this in 2 in enlarged cross section along the line 2-2 in 1 is shown. Characteristic here are laterally arranged depressions in the form of beads 4 , which in the embodiment substantially over the entire length of the shaft tube 3 extend.

In particular 2 shows, has the cross section of the shaft tube 3 an elongated inner contour, the circular arcs in end regions of the contour 5 . 6 and laterally tangential contour areas 7 trains the circular arcs 5 . 6 connect. The arcs are of different sizes and enclose the length of the shaft tube 3 extended subspaces, of which the larger subspace of an optic 8th is passed through, while the smaller subspace, which is indicated by a dashed line, the working channel 9 forms through which an instrument 10 is insertable.

If you compare 1 , so you can see that the optics 8th the main body 2 protrudes through and at its proximal end an eyepiece 11 indolent. That in the working channel 9 arranged instrument 10 is formed in the illustrated embodiment as a biopsy forceps and carries at the distal end a correspondingly formed jaw part 12 , The working channel 9 goes through the main body 2 , From its proximal end is the instrument 10 insertable, its proximal end as a forceps handle 13 is shown.

It must be emphasized here that the representations, in particular those of the 1 not to scale. The height H of the cross section, which in 2 is typically used in sizes of such instruments is typically 5.25 mm at a length of the shaft tube 3 in the order of 200 mm. The cross-sectional shape of 2 corresponds to the desired conditions.

In the 2 illustrated optics 8th consists essentially of the illustrated outer tube, as well as the shaft tube 3 usually made of stainless steel suitable for endoscopic equipment. Inside the outer tube of the optics 8th is an in 2 not shown optical system arranged, which consists for example of a plurality of successively arranged rod lenses, or optionally also of a glass fiber bundle. The instrument 10 that with the hatching in 2 As an integral rod is indicated, may be formed for the illustrated purposes of a forceps shank preferably with an outer tube or hose in which a pull rod is arranged to be longitudinally displaceable.

As 2 shows, lies the optics 8th with only slight undersize within the shaft tube 3 , For positional shifts of the optics 8th opposite the shaft tube 3 it comes to touch with this. The optics 8th can therefore only slightly in the working channel 9 shift into it. Disturbances caused by touching the instrument 10 are thus avoided.

This is caused by the beads 4 , the elongated depressions at the point of transition of the tangential contour areas 7 to the larger arc 6 form. The simplified standard shape without beads, as it represents, for example, the cited prior art, would allow much larger displacements of the optics, the touch of the instrument 10 lead to its more or less complete blockage.

The circular arcs 5 and 6 of the shaft tube 3 each form a center M and M ', through which the axis of symmetry S of the inner contour of the cross section extends. The inner contour of the cross section corresponds to the cross section of the inner surface of the shaft tube 3 , At the points of the circular arcs 5 respectively. 6 the inner contour has the radius r 'or r, as in 2 shown. There are also the outer radii in these places with R 'and R shown.

In order to keep the cross section of the shaft tube as close as possible, touching the perimeter of the working channel 9 and the optics 8th , Therefore, like 2 shows the centers M and M 'at a distance from the sum of the radii r and r' of the circular arcs 5 respectively. 6 ,

One recognizes in the opposite 2 something different representation of 3 in that symmetrically to the axis of symmetry S between the shaft tube 3 and the optics 8th or the working channel 9 two circular cross-sectional areas Q remain free, which for clarity in 3 hatched are shown.

These spaces Q, since in this embodiment a channel separation between an inlet and a drain channel is not provided, can be used together as a flushing channel, for example, for the inflow of flushing liquid in the operating area.

For the connection of the flushing channel to the outside in the illustrated embodiment, a liquid connection 14 provided in 1 is shown with the associated stopcock.

It can be worked intermittently, for example, the channel is used alternately for inflow or return flow. But it is also possible, for example, according to the proposal of the DE 10 2004 043 460 A1 or the WO 2009/083123 A1 the beads 4 to use as an external return channel.

In the cross section used for the invention of 3 Above all, the flow resistance of the usable for scavenging cross-sectional area Q is very important. This depends not only on the area but also very much on the exact shape of the cross-section, given the given narrow conditions.

Here, the findings of hydrodynamics in fluid flows in pipelines are taken into account. In essence, this results in that the flow resistance is determined at a location of the pipe cross-section of the wall distance. The further a cross-sectional location away from walls, the lower the flow resistance.

In the cross section of 6 are at the cross-sectional locations around the optics 8th around, so in a narrow gap with immediately adjacent walls, the flow resistance very high. It can be seen immediately that in the cross-sectional areas Q ( 3 ) the wall distances are large and thus the flow resistance is small.

For these reasons, the cross sections Q in 3 shown around. Although somewhat larger approximately triangular cross sections are actually available, but the corner areas are hardly usable because of their proximity to the wall.

Even if one tries to take these findings of hydrodynamics into account, theoretical considerations only lead the person skilled in the art to the goal with difficulty, since the geometric relationships are too complicated for the cross-sectional shapes present here. Therefore, the exact cross-sectional shape has been optimized in experiments.

The 4 . 5 . 6 and 7 show the results of experiments with different cross-sections. The cross section of the 7 corresponds to the cross section in the cited prior art. 6 shows the cross section of the present invention. The 4 and 5 others show possible cross sections here.

6 shows the cross section of 2 in a highly schematic representation. It is the shaft tube 3 and in this lying cross sections of the optics 8th or the working channel 9 shown, as well as the two beads 4 , In addition to the cross-sectional representation, a bar graph shows the achievable flow rate for rinsing liquid, as determined in the comparison test in ml / min.

Looking at the cross section of the 6 or the 2 , it can be seen that the flow cross-section is given substantially in the cross-sectional areas Q, which in 3 you can see. The figures show additional free cross-sectional areas between the optics 8th and the shaft tube 3 , Also for the instrument 10 There are still free cross-sectional areas around. However, these are unfavorable, have great resistance and therefore contribute little to the liquid flow.

The cross section of the 7 was used only for comparison purposes. He exits in the present case, since he does not allow sufficient support for the optics, as they have all other cross-sectional shapes.

In addition to the cross-sectional representations of 4 - 7 the flow rates are shown in each case. As you might expect, the flow rate is in the case of 4 very low and in the case of 7 very high. Surprising is the comparison of 5 and 6 , In contrast to what is suggested by an optical estimate, the cross section of the 6 much cheaper than the 5 ,

When comparing the 4 - 7 must also be noted that the outer contour of the cross section of the 7 even with the other cross-sectional shapes may not be exceeded. Increasing the outside diameter would require more stretching of the cervix, with significant pain and the risk of injury.

The invention was explained using the example of a hysteroscope, ie an endoscope for work in the uterus, through the cervical canal.

The invention is also eminently useful in urology when working with an ureteroscope beyond the bladder in the very narrow and sensitive ureter or through it with a ureterorenoscope in the kidney.

In the ureter and the cervical canal, the requirements for the shaft circumference are practically the same. Appropriate endoscopes can be used essentially in both areas.

LIST OF REFERENCE NUMBERS

1

hysteroscope

2

main body

3

steerer

4

Beading

5

first arc

6

second arc

7

tangential contour area

8th

optics

9

working channel

10

instrument

11

eyepiece

12

jaw

13

Pliers handle

14

liquid port

H

height

S

axis of symmetry

Q

Cross-sectional area

r '

first radius

r

second radius

R

outer radius

R '

outer radius

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 8416392 U [0002]
• DE 102004043460 A1 [0035]
• WO 2009/083123 A1 [0035]

Claims (7)

Gynecological or urological endoscope ( 1 ) with a shaft tube ( 3 ), whose cross-section has an elongate inner contour which in a first contour region has a first circular arc ( 5 ) with a first radius (r ') and in a second contour area a second circular arc ( 6 ) is formed with a second radius (r) which is greater than the first radius (r '), which circular arcs ( 5 . 6 ) with their centers (M, M ') at a distance from the sum of their radii (r, r') and on both sides of the center points (M, M ') extending symmetry axis (S) of the inner contour by tangential contour areas ( 7 ) are connected at their ends tangentially in the circular arcs ( 5 . 6 ), wherein in the second arc ( 6 ) formed in an optical tube optics ( 8th ) arranged with a holder ( 4 ) against shifting in the direction of the first circular arc ( 5 ) is secured, characterized in that the holder on the shaft tube ( 3 ) at least one inwardly formed recess ( 4 ) formed on one of the tangential contour areas ( 7 ) adjacent to the transition to the second arc ( 6 ) is arranged. Endoscope according to claim 1, characterized in that the recess as parallel to the shaft tube ( 3 ) running bead ( 4 ) is trained. Endoscope according to one of the preceding claims, characterized in that at each tangential contour area ( 7 ) a recess ( 4 ) is trained. Endoscope according to one of the preceding claims, characterized in that the inner contour of the shaft tube ( 3 ) is constant over its length. Endoscope according to one of the preceding claims, characterized in that the wall thickness of the shaft tube ( 3 ) is constant over its length and circumference. Endoscope according to one of the preceding claims, characterized in that the endoscope is a hysteroscope, a ureteroscope, a nephroscope or a cystoscope. Endoscope according to one of the preceding claims, characterized in that the outer radius (R ') of the shaft tube ( 3 ) in the region of the first arc ( 5 ) maximum 1.1 mm, the outer radius (R) of the shaft tube ( 3 ) in the region of the second circular arc ( 6 ) maximum 1.75 mm and the height (H) of the shaft tube ( 3 ) is a maximum of 5.25 mm.

Images