WO2017220652A1

WO2017220652A1 - Endoscope having a flexibly adhesively bonded optical waveguide

Info

Publication number: WO2017220652A1
Application number: PCT/EP2017/065239
Authority: WO
Inventors: Marion Scharschinger; Gregor Kiedrowski; Kai Schulz
Original assignee: Olympus Winter & Ibe Gmbh
Priority date: 2016-06-21
Filing date: 2017-06-21
Publication date: 2017-12-28
Also published as: DE102016111363B4; DE102016111363A1

Abstract

The invention relates to a medical endoscope, comprising an elongate shaft part, which is flexible at least in parts and through which at least one optical waveguide having a plurality of individual fibers runs in the longitudinal direction, characterized in that fibers of the optical waveguide are adhesively bonded by means of a flexible adhesive in a region in which said fibers run through a flexible section of the shaft part. The invention further relates to methods for assembling a medical endoscope according to the invention, characterized in that said methods comprise steps in which (a) an optical waveguide having a plurality of individual fibers is wetted with the flexible adhesive at least in some regions, (b) the adhesive is allowed to cure, and (c) the optical waveguide is then drawn into the shaft part; or (a) an optical waveguide having a plurality of individual fibers is drawn into the shaft part, (b) the flexible adhesive is sprayed into a section of the shaft part, and (c) the adhesive is allowed to cure.

Description

Endoscope with flexibly glued light guide

background

The invention relates to a medical endoscope referred to in the preamble of claim 1, and method for its assembly. In particular, the invention relates to medical endoscopes with a semi-flexible shaft part.

Endoscopes with a semi-flexible, i. an only partially flexible, shaft part, are e.g. used in urology and referred to as urethroscopes. Urethoscopes are surgical instruments used in urology for endoscopic work in the ureter and renal pelvis. To get into this area endoscopically, ie bloodless, the urethroscope is advanced from the outside through the urethra (urethra) into the bladder, from there through the ostium (mouth of the ureter with flap) introduced into the ureter (ureter) and in this to advanced to the operation area, eg up to a stone or a narrowing in the ureter or to the renal pelvis.

Urethoscopes are designed in endoscopic design with elongated shaft and can allow, for example, an observation of the surgical field with optics and associated lighting. The shaft tube of the urethroscope should have a length of at least about 330 mm. Since the ureter and in particular the ostium are very narrow, the shaft diameter should not be greater than about 3 to 4 mm. This results in a very long and thin configuration of the shaft tube. The stem tube of a urethroscope should be stiff to allow directing of the distal end from the proximal end, especially during difficult insertion into the ostium. The shaft tube is therefore generally rigid and has an outer metal tube, which gives him the necessary rigidity and which encloses the inner parts of the shaft part liquid-tight. However, a certain degree of elastic deformability of the shaft part is required in order to be able to reach the examination area during an intervention.

In the interior of the shaft tube, at least one viewing device is usually provided, as well as optical fibers for illumination and preferably a working channel, which allows the insertion of instruments, such as catheters, forceps, stone catcher, lithotriptors (stone smashing equipment), etc. In particular, for the illumination of the distal is usually before at least one optical fiber bundle in the shaft tube provided the urethroscopic work area. Freely trapped in the interior of an endoscope fiber optic bundles run at an elastic deformation of the shaft part risk to be damaged by the other retracted in the shaft part channels, as they exert pressure or friction on the fiber optic bundle and can damage individual fibers. A generic urethroscope is shown in DE 43 35 783 A1. The light guide formed of optical fibers fills out the space between the inner metal tubes and the outer metal tube.

WO 2016/041637 describes the fixation of optical fibers in an endoscope in that the distal end region of the fiber bundle is fastened in a sleeve and the sleeve is subsequently used as a component and installed with the endoscope optics. For attachment and easier assembly, the fiber bundle can be glued in the sleeve. The fiber bundle is inserted with the sleeve in another tube, which is arranged as an outer tube, which also forms the outer wall of the endoscope optics.

It is known from DE 199 28 289 A1 to seal an endoscope, such as a urethroscope, at the distal end of its shaft part with a window for the optics and sealed with a sufficiently dense adhesive bond of the fibers of the light guide bundle. However, the optical fiber bundle can be laid freely in the sealed housing of the endoscope. A disadvantage of these known constructions is that the walls of the shaft region and the elements passing through the shaft in semiflexible endoscopes are subject to considerable stresses as soon as a flexible section of the shaft region is bent. There may be friction between the laid in the shaft area elements and in particular damage to the exposed optical fibers. Damage can occur, for example, if the light fibers fall between the shaft elements in the shaft area or between these and the shaft inner wall during shaft bending. In order to circumvent these problems, light guides have occasionally been fed into a separate light guide tube, eg of metal, which was laid together with the other channels in the endoscope shaft. However, this solution is associated with a high workload and unnecessarily increases the volume occupied by the light guide in the small shaft diameter.

Object of the present invention is therefore to form a generic endoscope such that the therein contained, a plurality of individual fibers having optical fibers are not damaged when bending a portion of the shaft portion and that at the same time occupied by the light guide volume in the interior of the shaft portion as low as possible is held.

DESCRIPTION OF THE INVENTION The problem is solved by an endoscope having the characterizing features of claim 1 and by methods for its assembly, which have the characterizing features of claim 10 or 12. The subclaims relate to advantageous embodiments of the invention. According to the invention, fibers of the optical waveguide are bonded by means of a flexible adhesive at least in a region of the optical waveguide which passes through a flexible section of the shaft part. This stabilizes the optical fiber and protects it from damage due to friction or pressure. In particular, it is not necessary to protect the light guide by a jacket with a separate light guide channel.

Thus, in a first aspect, the invention relates to a medical endoscope with an elongate, at least partially flexible, shaft part, which extends in the longitudinal direction is traversed by at least one, a plurality of individual fibers having optical fiber, characterized in that fibers of the optical fiber are glued in a region in which they pass through a flexible portion of the shaft portion by means of a flexible adhesive.

The medical endoscopes according to the invention have an elongate shaft part and a control part which adjoins it proximally (also referred to as the main body). The shaft part is preferably formed by a sealed housing. This can be formed for example in the form of a stem tube. In other words, the shaft part thus preferably comprises an outer handle tube or outer tube. In addition, the shaft part can contain further inner tubes, as well as various elements retracted into the shaft part, such as e.g. Working channels, fiber tubes, optical channels, other light guides and the like. The person skilled in the art will find suitable materials, e.g. Steel, known from which the housing of the shaft part can be made. In particular, materials are suitable which ensure sufficient flexibility of the shaft part. Thus, the shaft part can bend during examinations to follow the organ passages, in particular the urethra and the ureters.

It is particularly preferred that the medical endoscope is a urethroscope. Urethroscopes (synonymous: ureteroscopes) are used for investigations of the ureters and kidneys and therefore have a particularly long shaft part, which must have a corresponding flexibility. Alternatively, however, the medical endoscope can also be any other endoscope which has or can have a flexible or semi-flexible shaft part. "Semiflexible" in this context means that the shaft part comprises at least one flexible and at least one less flexible or inflexible section In other words, the shaft part is elastically deformable at least in sections, thereby enabling the user to reach the examination site through the organ passageways during the examination without damaging organs Rule, ie be reversible with proper, normal use of the endoscope (passive), so that the deformation on removal of the load, for example, when removing the endoscope from the body of the patient, disappears, so that the shaft part returns to its original shape accepts. A flexible portion of the shaft part preferably has a round cross-section.

As described above, preferred materials for producing the shaft part are known to those skilled in the art. A preferred material for forming the outer tube is, for example, steel. According to the invention, in particular the ratio of shaft diameter to the length of the shaft is selected so that the shaft is at least partially flexible. The diameter of the shaft part is very small. Thus, the shaft part may have a diameter of about 0.5 mm to 8 mm, preferably about 1 mm to 5 mm, particularly preferably 2 mm to 4 mm. The length of the shaft part, however, is so long that a comfortable handling and the accessibility of the surgical site is guaranteed. Thus, the shaft portion may have a length of about 200 mm to 600 mm, preferably 300 mm to 500 mm, more preferably about 330 to 430 mm. The shaft part does not have to be flexible or flexible over the entire length. However, it is preferred that the flexible portion of the shaft portion has a length of about 100 mm to 500 mm, more preferably 180 mm to 380 mm, most preferably 250 mm to 350 mm. Accordingly, the fibers of the light guide are preferably adhered to each other over a length (along the longitudinal axis of the light guide) of 100 mm or more, more preferably to a length of 180 mm or more by means of a flexible adhesive.

In addition to the flexible portion, the shaft portion preferably also includes a stiffened portion that is less flexible than the flexible portion. "Stiffened" in this context means that the portion is not or only significantly reduced in extent relative to the flexible portion This stiffened section is preferably formed in the distal region of the shaft part, This design ensures that the user of the endoscope is able to move the distal end of the endoscope accurately into the desired area , Stiffened portion proximal to a flexible portion of the shaft portion.

The person skilled in the art discloses methods of stiffening the shaft part in a provided section. Thus, the stiffened portion of the shaft portion, for example, in cross section have a shape that deviates from the circular shape, ie have a non-circular cross-section. The stiffened portion may be, for example, oval or triangular, with the latter alternative, the corners of the triangular shape are rounded. The (eg distal) stiffened portion of the stem portion may have a length of about 30 mm to 180 mm, preferably from about 50 mm to 150 mm, more preferably from about 80 mm to 120 mm. In a preferred embodiment, the shaft portion has a first stiffened portion of about 50 to 150 mm in length and a second flexible portion of about 180 to 380 mm in length.

The shaft portion is traversed longitudinally by a fiber having a plurality of individual fibers. This means that the optical fiber having a plurality of individual fibers extends substantially the entire length of the shaft part, i. from its proximal end to its distal end. Since the light guide is protected according to the invention by bonding with a flexible adhesive, the light guide will remain substantially intact even after regular use of the endoscope. This means, for example, that even after repeated use more than 70%, preferably more than 80%, more preferably more than 90% of the fibers of the optical fiber are intact over the entire length of the shaft part. "Intact" in this context means that the fiber optic cable is not affected by damage, such as fiber rupture, which is capable of directing light from a light source to the distal end of the shaft portion The optical waveguide bundle has in each case a plurality of optical fibers, for example a plurality of optical fibers, optical fibers may, for example, be glass fibers or optical fibers The optical waveguide or the optical fiber bundle can be coupled or connected to an external light source.

The light guide, i. the optical fiber bundle, preferably has a thickness of 0.4 to 0.8 mm, more preferably 0.5 to 0.71 mm.

The fibers of the light guide are glued in a region in which they pass through a flexible section of the shaft part by means of a flexible adhesive. "Area" or "area" are used herein synonymously with "section" and "section", respectively. Bonding with a flexible adhesive ensures that, when a flexible section of the shaft part is bent, the light guide can adapt to the movement of the shaft part and at the same time be protected against pressure and friction by others in the shaft Shaft part contained components (eg channels) is protected. At the same time, it is no longer necessary to protect the optical fiber from the other components by enclosing it with another channel wall. Also, the retraction of the bonded optical fiber during assembly is significantly simplified, so that the use of, for example, a light guide sleeve in the end regions of the light guide is no longer required.

In a preferred embodiment, the optical fiber having a plurality of individual fibers is thus not surrounded by a light guide channel and / or in its end regions by a sleeve. Instead, the optical fiber passes through the shaft portion immediately adjacent, or merely separated by an adhesive layer, from further channels, such as e.g. the working channel and the optical channel (also known as fiber channel).

According to the invention, any flexible adhesive can be used for bonding the fibers of the light guide. After curing, the flexible adhesive should have sufficient flexibility that allows the light guide to adapt to the expected elastic deformation of the shaft part. At the same time, after curing of the flexible adhesive, the bond is strong enough to hold the fibers of the light guide together, i. to fix each other. Suitable flexible adhesives are e.g. Silicone adhesives.

In a particularly preferred embodiment, the flexible adhesive is a silicone adhesive. Suitable silicone adhesives are commercially available and known to those skilled in the art. A suitable silicone adhesive is e.g. Elastosil E41. According to the invention, the fibers of the light guide are glued together by means of a flexible adhesive. This means that fibers of the optical waveguide are glued together to form a flexible fiber bundle. In particular, the fibers are bonded in such a way that essentially all fibers of a light guide are held together in the bonded section of the light guide. For this purpose, not necessarily every single fiber in the interior of the light guide must be glued with their neighboring fibers. However, as a rule, at least the fibers lying in the optical fiber will be glued to their neighbors.

In addition, the light guide may be at least partially surrounded by the flexible adhesive in the relevant section. The adhesive layer applied around the light guide is preferably on average thinner than 0.1 mm, more preferably thinner than 0.05 mm, even more preferably thinner than 0.01 mm. Furthermore, the light guide can be connected to the inner wall of the shaft part by means of the flexible adhesive. In other words, the free space within the flexible portion or portions of the shank portion may at least partially be filled by the flexible adhesive. The free space is the space that is not occupied by the light pipe itself or by the various other components described herein, such as working and optical channels. The free space is not the space within the latter or other channels, which are retracted in the shaft portion, but the remaining free space within the inner wall of the shaft portion. In one embodiment, the free space within the flexible portion or portions of the shank portion is substantially completely filled by the flexible adhesive.

The light guide may have a round cross-section, but may also adapt to the free space in the shaft part and fill it. Since the light guide is flexibly glued, its cross-sectional shape can also vary.

The bonding takes place in a region in which the fibers pass through a flexible section of the shaft part. The fibers are preferably glued together over the entire length of a flexible section, or at least over 80%, preferably at least 90%, particularly preferably at least 95%, of the length of a flexible region. It is particularly advantageous if the fibers are glued together over the entire length of a flexible section.

In principle, it is advantageous to bond the fibers of the light guide essentially in all areas which pass through a flexible section of the shaft part. It is therefore preferred according to the invention that the fibers of the optical waveguide are glued over at least 90%, preferably at least 95% or, most preferably, over about 100% of the length of the regions of the optical waveguide which pass through flexible sections of the shaft part. The endoscopes according to the invention generally have a shaft part which consists of at least 60%, preferably at least 70%, more preferably at least 80% of flexible sections. Thus, it is preferred that the optical fiber is bonded over a length of at least 60%, preferably at least 70%, more preferably at least 80% of the shaft portion.

Fibers of the light guide or the light guide can / additionally at the distal end of the shaft portion and / or at the proximal end of the shaft portion by means of an inflexible Adhesive glued. Thus, for example, the shaft part at the distal end can be sealed sealed by means of a sufficiently tight bond with an inflexible adhesive and, for example, a window for the optics. In this case, it is preferred that the flexible adhesive and the inflexible adhesive are spaced apart in the shaft part.

The endoscope may include one, two, three or more optical fibers described herein. In a preferred embodiment, the endoscope contains two light guides. In addition to the light guide (s), the endoscope may include other components, e.g. a fiber channel, working channel and the like included. Thus, the endoscope typically includes e.g. an endoscope optic, which is usually laid in a fiber channel.

In a further aspect, the invention relates to a method for assembling a medical endoscope according to the invention, characterized in that it comprises steps in which (a) a light waveguide having a plurality of individual fibers is wetted in areas with the flexible adhesive, (b) curing the adhesive leaves and (c) subsequently retracts the light guide into the shaft part.

The partial wetting of the fiber bundle in step (a) may be e.g. by immersing the area in the adhesive or by applying the adhesive to the desired area of a bundle. The application / immersion may e.g. take place in the desired region of the light guide by the area of the light guide is pulled together with the flexible adhesive through an opening which is only slightly larger than the cross section of the light guide. This means that the inner diameter of the opening z. B. 0.5 to 5 mm may be greater than the outer diameter of the light guide, preferably at most 3 mm, more preferably at most 1, 5 mm. In particular, it is not necessary to wet each fiber of the light guide individually with the adhesive. Surprisingly, it has been found sufficient to bond the fiber bundle to the adhesive by external, partial (i.e., partial) wetting.

It is understood that the fiber bundle is preferably wetted in a region which, after step (c), passes through a flexible section of the shaft part, ie in a region which is intended for insertion into a flexible section of the shaft part. Subsequently, in step (b), the adhesive is cured. The curing of the adhesive can be done for example by air drying of the adhesive. By such a gentle Drying in air ensures that the necessary flexibility of the adhesive is maintained.

After curing of the flexible adhesive, the optical fiber can finally be drawn into the shaft part in step (c). Processes for this are known to the person skilled in the art. The feeding can be done manually or automatically.

In an alternative aspect, the invention relates to a method for assembling a medical endoscope according to the invention, characterized in that it comprises steps of (a) pulling a light guide having a plurality of individual fibers into the shaft part, (b) placing the flexible adhesive in one Injects the portion of the stem portion and (c) sets the adhesive to cure.

A method for drawing a fiber having a plurality of individual fibers in the shaft part, as described elsewhere, known to those skilled in the art. Preferably, the retraction of the unglued fiber bundle is done manually.

In this method, the optical fiber is first drawn into the shaft part and only then wetted by injecting the adhesive area or sections of the adhesive. The injection of the adhesive may e.g. done with a cannula. In this way, the desired sections in the shaft part are achieved precisely. It will be appreciated that the portion into which the adhesive is injected in step (b) is preferably or comprises a flexible portion of the shank portion. The curing of the adhesive in step (c) occurs as described elsewhere herein.

Brief description of the figures

In the drawings, embodiments of the invention are shown schematically. Show it:

1 is a side view of a urethroscope according to the invention,

2 shows a section along line III-III in Fig. 1 by a flexible portion of the shaft portion, 3a shows a section through a distal, stiffened portion of the shaft portion, and

3b shows a section through a distal, stiffened portion of an alternative shaft portion.

EMBODIMENTS Further advantages, characteristics and features of the present invention will become apparent in the following detailed description of embodiments with reference to the accompanying drawings. However, the invention is not limited to these embodiments. Fig. 1 shows a side view of a urethroscope 2 according to the invention with a main body 6 and a distally connected tubular elongated tubular member 8 to be inserted into the patient's body. The main body 6 may e.g. an eyepiece and an introductory part. The shank part 8 and the main body 6 are sealed in an unspecified manner connected to each other, for example, glued, soldered or the like.

The proximal end of an optical fiber bundle, which runs through the interior of the shaft part 8 in the longitudinal direction as far as the distal end of the shaft part 8, can be fastened in a connecting piece on the main body 6 that serves as the end of a light guide (not shown).

Furthermore, from the main body 6, an eyepiece neck, also not shown, can depart, through which an optic extends, which is also guided through the shaft part 8 to the distal end of the urethroscope 2. At the proximal end of the optics may be provided on the eyepiece neck an eyepiece.

The length of the shaft part 8 is at a urethroscopic 2 usual training, for example, 400 to 500 mm. The outer diameter of the shaft part, as well as the outer diameter of the outer metal tube should not exceed a maximum of about 4 mm. In such a cross-section of the outer metal tube results, substantially independent of the wall thickness, a certain stiffness of the pipe, which in bending of the pipe to an elongation of the material on the outside and a compression of the material on the inside (based on the center of the bending radius) leads.

At its distal end, the stem portion 8 is sealed in a suitably sealed manner, e.g. with a window for an optic in the fiber channel 16 and with a sufficiently tight adhesion of the light guide 14 or the light guide 14. The bonding is carried out for example by an inflexible adhesive. The well-sealed shaft portion 8 ensures that the optics arranged inside and the light guide or fibers 14 are not impaired by water or steam penetrating when working with the urethroscope 2 or during sterilization.

The cross-sectional illustration 12 of FIG. 2 shows that the shank part 8 has in a flexible section an outer circumference of the shank wall 20 of round cross-section, which may preferably be formed as a metal tube. The interior of the shaft part 8 surrounded by this shank wall 20 receives two inner channels in the illustrated embodiment, the fiber channel 16 (also: optical channel) and the working channel 26. Both the fiber channel 16 and the working channel 26 can be formed as metal tubes. The fiber channel 16 encloses the optics, which transmits the observed image from an objective arranged at the distal end 10 of the shaft part 8 to the eyepiece. The working channel 26 is formed as a free channel in which an instrument (e.g., a laser lithotripter) can be advanced through the insertion member, the proximal laser generator of which is also not shown. In the interior of the shaft part 8, two light guides 14 are also laid, which are preferably formed as a fiber optic bundle, and serve to illuminate the field of view. The light guides 14 are bonded with a flexible silicone adhesive, which protects the light guide 14 from damage by pressure and friction. In addition, in the embodiment shown, the entire interior (not occupied by channels or light guides) of the shown, flexible section of the shaft part 8 is filled with a flexible adhesive 22. This was inventively achieved in that the flexible adhesive was injected into the flexible portion of the shaft portion 8.

At the proximal end of the shaft part 8, the light guide 14 can be led out of the main body 6 via a light guide connection. There, a light conductor connection cable can be connected to a cold light source, not shown. 3 a and 3b each show a section through a distal, stiffened section of different shaft parts 8. It can be seen that the shaft part 8 shown in FIG. 3 a has an oval outer cross section in a distal, stiffened section, while it has an oval outer cross section Background of Figure 3a recognizable - proximal of this section has a flexible portion with a round outer cross-section. The shaft part 8 shown in FIG. 3 a is part of a 1-channel instrument, since the shaft part can be seen to have a working channel 26.

It can also be seen that the shank part 8 illustrated in FIG. 3b has a triangular outer cross section with rounded corners in a distal, stiffened section, while - as can be seen in the background of FIG. 3b - there is a flexible section with a round section proximal to this section Has outer cross section. The shank part 8 shown in FIG. 3b is part of a 2-channel instrument, since the shank part recognizably has two working channels 26. Due to the oval or triangular outer cross section, the illustrated distal portion of the shaft portion 8 is stiffened.

In addition to the one or more working channels 26, the shaft parts have a fiber channel 16, in which an optical system can be retracted. On the shaft part, a dilatation nose 18 is further arranged. It can be seen that the light guides 14 fill substantially the entire free space within the shaft part 8.

Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that the invention is not limited to these embodiments, but rather modifications are possible in such a way that individual features omitted or other combinations of individual features presented realized unless the scope of the appended claims is exceeded. The present disclosure includes all combinations of the featured individual features.

LIST OF REFERENCE NUMBERS

urethroscope

main body

shank part

distal end of the shaft part

Cross section of the shaft part

optical fiber

fiber channel

Dilatationsnase

shank wall

flexible adhesive

Wall of the working channel

working channel

Claims

claims:

Medical endoscope with an elongate, at least partially flexible shaft portion, which is traversed in the longitudinal direction of at least one, a plurality of individual fibers having optical fiber, characterized in that fibers of the optical fiber in a region in which they pass through a flexible portion of the shaft portion, by means of a glued flexible adhesive.

Medical endoscope according to claim 1, characterized in that the

Fibers of the optical fiber are glued together over a length of 100 mm or more by means of a flexible adhesive.

Medical endoscope according to one of the preceding claims, characterized in that the flexible adhesive is a silicone adhesive.

Medical endoscope according to one of the preceding claims, characterized in that the endoscope is a urethroscope.

5. Medical endoscope according to one of the preceding claims, characterized in that the light guide is connected by means of the flexible adhesive with the inner wall of the shaft part. Medical endoscope according to one of the preceding claims, characterized in that the free space within the flexible portion or portions of the shaft part is at least partially filled by the flexible adhesive.

Medical endoscope according to one of the preceding claims, characterized in that fibers of the light guide are additionally glued at the distal end of the shaft portion and / or at the proximal end of the shaft portion by means of an inflexible adhesive, wherein preferably the flexible adhesive and the inflexible adhesive in the shaft portion are spaced from each other ,

Medical endoscope according to one of the preceding claims, characterized in that the shaft part has a first, distal, stiffened portion and a second flexible portion adjoining this first portion proximally.

Medical endoscope according to one of the preceding claims, characterized in that the first, stiffened portion of the shaft portion has a non-circular cross-section.

Method for assembling a medical endoscope according to one of the preceding claims, characterized in that it comprises steps in which one

(a) at least partially wetting a light conductor having a multiplicity of individual fibers with the flexible adhesive,

(b) allowing the adhesive to harden and

(c) then pulls the light guide into the shaft part.

A method according to claim 10, characterized in that the wetting in step a) takes place by the wetting portion of the light guide is pulled together with the flexible adhesive through an opening whose inner diameter is at most 5 mm greater than the outer diameter of the light guide.

2. A method for assembling a medical endoscope according to one of claims 1 to 9, characterized in that it comprises steps in which one

(a) draws a fiber having a plurality of individual fibers in the shaft part,

(b) injecting the flexible adhesive into a portion of the shaft portion and

(c) cure the adhesive.