Video endoscope

Abstract

Video endoscope with an elongated shaft (3), a main body (2) arranged proximally to the shaft (3), and a cable (6) permanently attached to the main body (2) for supplying and / or conveying control signals, video signals and / or illumination to and from the video endoscope, wherein the cable (6) comprises: - A core comprising at least one optical fiber bundle (10), at least one video signal line (11, 12), and / or at least one control signal line (13); - A mechanical protective layer (20) surrounding the core; and - A sheathing tube (21) surrounding the protective layer (20); wherein the video endoscope further comprises a transition body (25) which is inserted into the main body (2) in a sealing manner on the endoscope side, and which receives the sheathing tube (21) in a sealing manner on the cable side; and wherein in the area of ​​the cable connection a kink protection sleeve (35) is arranged around the sheathing tube (21), which overlaps the transition body (25);characterized in that the video endoscope further comprises a clamping ring (45) which is supported on the transition body (25) and is pulled towards the main body (2) by means of a first clamping nut (46), so that the transition body (25) is pressed against a round cord seal (40) arranged between the transition body (25) and the main body (2), and which simultaneously presses the kink protection sleeve (35) against the transition body (25) in such a way that a cavity (36) formed between the kink protection sleeve (35) and the transition body (25) is sealed against the interior of the main body (2) and against the environment.

Description

The invention relates to a video endoscope having an elongate shaft, a main body arranged proximally of the shaft, and a cable which is fixedly connected to the main body for the supply and / or dissipation of control signals, video signals and / or illumination light to or from the video endoscope, wherein the cable comprises: a core comprising at least one optical fiber bundle, at least one video signal line, and / or at least one control signal line; a mechanical protective layer surrounding the core; and a sheath tube surrounding the protective layer; wherein the video endoscope further comprises a transition body which is inserted sealingly into the main body on the endoscope side and which receives the sheath tube sealingly on the cable side; and wherein a kink protection sleeve is arranged around the sheath tube in the region of the cable connection, said kink protection sleeve engaging over the transition body.Videoendoscopes have been used for a long time in medicine in order to examine cavities in the body of a patient that are difficult to access. For this purpose, videoendoscopes have an elongated shaft which is introduced into the body cavity to be examined through a natural or surgically produced opening. The shaft can be flexible or rigid depending on the intended application. An objective is arranged at a distal end of the shaft, with which objective a structure of interest can be imaged in the body cavity to be examined. An image produced by the lens is imaged onto an electronic imager which generates video signals representing the image.To illuminate the body cavity to be examined, optical fibers are usually laid in the shaft of a video endoscope, which emit light coupled in at a proximal end of the video endoscope in a directed manner at its distal end.For outputting the video signals, for inputting and outputting further control signals and / or for supplying illumination light, modern video endoscopes are equipped with a permanently mounted cable. The cable is fixedly mounted on the video endoscope in order to avoid releasable connections in the region near the patient that are difficult to clean. At an end of the cable remote from the video endoscope, one or more plug connectors are arranged in order to connect the cable detachably to a control device and / or to a light source. These connectors can be made larger and are thus less problematic to clean than connectors directly on the video endoscope.Special tightness requirements must be placed on the connection point of the cable to the video endoscope. In this case, the connection point must firstly be made so tight that moisture cannot penetrate into the interior of the video endoscope during use and during preparation of the video endoscope. In particular, when processing in an autoclave with steam under elevated pressure, adequate sealing is essential. On the other hand, the connection point must not have any leaks through which germ-laden liquids or dirt can penetrate into regions which are difficult to access.Furthermore, the connection point should be designed such that the assembly and / or disassembly is as uncomplicated as possible.These requirements in combination are only incompletely fulfilled in known video endoscopes. It is therefore an object of the invention to provide a video endoscope which is improved with regard to the tightness and the assembly capability of the cable connection.This object is achieved according to the invention by a video endoscope having an elongate shaft, a main body arranged proximally of the shaft, and a cable which is fixedly connected to the main body for the supply and / or dissipation of control signals, video signals and / or illumination light to or from the video endoscope, wherein the cable comprises: a core comprising at least one optical fiber bundle, at least one video signal line, and / or at least one control signal line; a mechanical protective layer surrounding the core; and a sheath tube surrounding the protective layer; wherein the video endoscope further comprises a transition body which is inserted sealingly into the main body on the endoscope side and which receives the sheath tube sealingly on the cable side; and wherein a kink protection sleeve is arranged around the sheath tube in the region of the cable connection, said kink protection sleeve engaging over the transition body; which is further developed in that the video endoscope further has a clamping ring which is supported on the transition body and is pulled in the direction of the main body by means of a first clamping nut in such a way that the transition body is pressed against a round cord seal arranged between the transition body and the main body, and which simultaneously presses the anti-kink sleeve against the transition body in such a way that a cavity formed between the anti-kink sleeve and the transition body is sealed against the interior of the main body and against the environment.By the embodiment of the video endoscope according to the invention, the sealing of the main body and the sealing of an end region of the anti-kink sleeve can simultaneously take place in a simple manner by a single element, namely the clamping ring. For this purpose, only the first clamping nut needs to be tightened.In this case, the main body can have an external thread on the cable side, onto which the first clamping nut is screwed.The materials of the first clamping nut, the clamping ring and the anti-kink sleeve can preferably be selected such that a coefficient of friction of the material pairing of the first clamping nut and clamping ring is lower than a coefficient of friction of the material pairing of the clamping ring and anti-kink sleeve. This ensures that the clamping ring does not twist on the anti-kink sleeve while the first clamping nut is tightened. Damage to the anti-kink sleeve by the clamping ring is thus avoided.The clamping ring and the first clamping nut may have complementary radial stop surfaces in a possible embodiment of a video endoscope according to the invention. Such stop surfaces allow simple tightening of the first clamping nut without the clamping ring tilting or tilting.In a particularly preferred embodiment of a video endoscope according to the invention, the transition body can comprise a first part body and a second part body, wherein the first part body sealingly receives the enveloping tube and the second part body is pressed against the round cord seal. In this case, a largest outer diameter of the first part body can be smaller than a smallest inner diameter of the main body.By the corresponding embodiment of the transition body, it is possible, after removal of the second part body, to push the main body over the cable beyond the first part body, in order to thus reach components inside the main body.In this case, the main body can overlap the first part body, and the round cord seal can be arranged between the main body and the first part body in such a way that it bears radially sealingly against the main body and against the first part body by the compressive force of the second part body.The first part body and the second part body can be screwed to one another via a thread.In a further possible embodiment of a video endoscope according to the invention, the first part body can comprise a second clamping nut which compresses an elastic sealing element arranged between the first part body and the enveloping tube. Here too, a radial expansion of the sealing element can be brought about by a compression of the sealing element in the axial direction, so that it rests sealingly against the enveloping tube and against the first part body.In this case, the clamping ring can press the anti-kink sleeve against the second clamping nut.The invention is explained in more detail below with reference to some exemplary illustrations, wherein the exemplary embodiments shown are intended exclusively to better understand the invention, without restricting it.The following are shown: FIG. 1 : a video endoscope, FIG. 2 : a cable, FIG. 3 : shows the cable connection of a video endoscope.FIG. 1 shows a video endoscope 1 having a main body 2 and an elongated shaft 3. The shaft 3 is closed at the distal end by a window 5.A supply and signal cable 6 serves to connect the video endoscope 1 to a light source, not shown, and to a control device, likewise not shown. Finger switches 7, 8 are provided on the main body 2 of the video endoscope 1, by means of which the video endoscope 1 and, if appropriate, the light source and / or the control device can be controlled.FIG. 2 shows the structure of the cable 6 in cross section. The cable 6 comprises a core comprising an optical fibre bundle 10, video signal lines 11, 12 and a signal line 13.The optical fiber bundle 10 is sheathed with a special protective tube 15 for protecting the sensitive fibers.The video signal line 11 is designed as a coaxial cable having an inner conductor 16, a dielectric 17, an outer conductor 18 and a sheathing 19. The construction of the video signal line 12 is similar. The two video signal lines 11, 12 enable a stereo video signal to be transmitted when the video endoscope 1 is designed as a stereo video endoscope. The cable 6 may also comprise only a single video signal line.In the example shown, the signal line 13 comprises three individually insulated wires 13 a, 13 b, 13 cin a common sheathing. The signals of the finger switches 7, 8 can be transmitted by the signal line, for example.The core of the cable 6 is surrounded by a mechanical protective layer 20, which can be a steel coil, for example. The protective layer 20 is surrounded by a sheath tube 21, which simultaneously constitutes an insulation of the cable 6.An elastic membrane 22 can be provided on the inside of the protective layer 20 in order to protect damage to the core of the cable 6 by the edges of the steel coil.The arrangement of the components of the core of the cable 6 is shown with greatly enlarged spacings in order to make a better overview possible. In fact, the optical fibre bundle 10 and the individual leads 11, 12, 13 are arranged close together in the core of the cable 6 in order to minimize the cross-section of the cable 6.FIG. 3 shows the cable connection of a video endoscope in longitudinal section. The cable 6 is depicted on the right-hand side, wherein only the mechanical protective layer 20 and the sheath tube 21 are shown for the sake of better clarity. The core of the cable 6 is not shown. On the right side, the main body 2 is shown.Between the main body 2 and the cable 6 a transition body 25 is shown, which consists of a first part body 26 and a second part body 27.The first part body 26 has a tubular extension 30 on the cable side, which extends over the endoscope-side end of the cable 6. Between the extension 30 and the cable 6, an elastic sealing element 31 is arranged, which is axially braced by a clamping nut 32 screwed onto the extension 30. The sealing element 31 expands radially and thus forms a seal between the enveloping tube 21 and the extension 30.In order to improve the effectiveness of the sealing element 31, the sheath tube can be supported from the inside at its endoscope-side end by a sleeve, not shown. The sleeve can be arranged between the protective layer 20 and the enveloping tube 21 or within the protective layer 20.The cable connection further comprises an anti-kink sleeve 35 which rests closely on the outer sleeve 21 and engages over the extension 30 of the transition body 25.To seal the transition body 25 against the main body 2, a round cord seal 40 is provided, which is supported on the endoscope side on a support ring 41 and on the outside on the main body 2. The support ring 41 serves to provide a sufficiently large contact surface for the round cord seal 40.On the inside, the round cord seal rests on the first part-body 26 of the transition body 25, and on the cable side, the second part-body 27 of the transition body 25 rests on the round cord seal 40.On the cable side, the second part-body 26 has a radial stop surface 42 against which a clamping ring 45 bears. The clamping ring 45 is screwed onto the main body 2 by a clamping nut 46. For this purpose, the main body 2 has an external thread, not shown.The clamping nut 46 and the clamping ring 45 have complementary radial stop surfaces 47, 48.By tightening the clamping nut 46, the clamping ring 45 is pulled toward the main body 2. In this case, the second part body 27 presses against the round cord seal 40, with the result that the latter expands radially and in the process bears sealingly against the first part body 26 and the main body 2. Thereby, the inside of the main body 2 is reliably protected from the entry of moisture from the outside.At the same time, the cable-side end of the clamping ring 45 presses against the anti-kink sleeve 35, so that the latter is drawn firmly against the first part body 26 or against the clamping nut 32. As a result, the cavity 36 is reliably sealed against the penetration of dirt or germs from the outside.In order to prevent the clamping ring 45 from twisting when the clamping nut 46 is tightened, the materials of the clamping ring 45, the clamping nut 46 and the anti-kink sleeve 35 are selected such that a coefficient of friction of the material pairing of the clamping nut 46 and clamping ring 45 is significantly lower than a coefficient of friction of the material pairing of the clamping ring and anti-kink sleeve 35.The clamping nut 46 can preferably be made of a thermoplastic material such as PEEK, while the clamping ring 45 itself is preferably made of metal, for example medical stainless steel. The anti-kink sleeve 35 can consist, for example, of silicone.The surface of the clamping ring 45 can be adapted visually and haptically to the requirements of a user by means of a coating. For example, a chemically particularly insensitive surface can be achieved by coating with tin nitrate.On the cable side, the clamping nut 46 and the clamping ring 45 have a conical outer contour. The clamping nut 46 bears with its inner surface as free of gaps as possible on an outer surface of the clamping ring 45. The above-mentioned materials permit a correspondingly closely tolerated production of the components at reasonable costs.When the interior of the main body 2 has to be accessed for maintenance or repair purposes, the cable connection described can be easily disassembled. For this purpose, the clamping nut 46 is loosened and pushed to the right over the cable 6. Subsequently, the clamping ring can also be slid to the right over the cable 6.Next, the second part body 27 is detached from the first part body 26 and also slid to the right via the cable 6. Thereafter, the main body 2 itself with the back-up ring 41 and the round-line seal 41 can be slid over the cable 6 to expose the components to be maintained.After dismantling the cable connection, the elastic round cord seal 41 must optionally be replaced. For this purpose, the old round cord seal 41 can be cut in order to remove it. The new round cord seal, when internal connections of the leads 11, 12, 13 running in the cable 6 and the optical fibre bundle 10 are released, can be slipped over the corresponding connectors and over the first part body 26 without any problem. The round cord seal must then still be guided on the inside through the support ring 41. After the completion of the maintenance, the cable connection is installed in the reverse sequence.

Claims

Video endoscope having an elongate shaft (3), a main body (2) arranged proximally of the shaft (3), and a cable (6) fixedly connected to the main body (2) for supplying and / or deriving control signals, video signals and / or illumination light to or from the video endoscope, wherein the cable (6) comprises the following: - a core comprising at least one optical fibre bundle (10), at least one video signal line (11, 12) and / or at least one control signal line (13); - a mechanical protective layer (20) surrounding the core; and - an enveloping tube (21) surrounding the protective layer (20); wherein the video endoscope further comprises a transition body (25) which is inserted sealingly into the main body (2) on the endoscope side and which receives the enveloping tube (21) sealingly on the cable side; and wherein, in the region of the cable connection, an anti-kink sleeve (35) is arranged around the sheath tube (21), which extends over the transition body (25); characterized in that the video endoscope further has a clamping ring (45), which is supported on the transition body (25) and is pulled in the direction of the main body (2) by means of a first clamping nut (46), such that the transition body (25) is pressed against a round cord seal (40) arranged between the transition body (25) and the main body (2), and which simultaneously presses the anti-kink sleeve (35) against the transition body (25) such that a cavity (36) arising between the anti-kink sleeve (35) and the transition body (25) is sealed against the interior of the main body (2) and against the environment.Video endoscope according to Claim 1, characterized in that the main body (2) has an external thread on the cable side, onto which the first clamping nut (46) is screwed.Video endoscope according to Claim 1 or 2, characterized in that the materials of the first clamping nut (46), of the clamping ring (45) and of the anti-kink sleeve (35) are selected such that a coefficient of friction of the material pairing of the first clamping nut (46) and clamping ring (45) is lower than a coefficient of friction of the material pairing of clamping ring (45) and anti-kink sleeve (35).Video endoscope according to one of the preceding claims, characterized in that the clamping ring (45) and the first clamping nut (46) have complementary radial stop surfaces (47, 48).Video endoscope according to one of the preceding claims, characterized in that the transition body (25) comprises a first part-body (26) and a second part-body (27), wherein - the first part-body (26) accommodates the enveloping tube (20) in a sealing manner, and - the second part-body (27) is pressed against the round cord seal (40).Video endoscope according to Claim 5, characterized in that a largest outer diameter of the first part-body (26) is smaller than a smallest inner diameter of the main body (2).Video endoscope according to Claim 6, characterized in that the main body (2) engages over the first part-body (26), and in that the round cord seal (40) is arranged between the main body (2) and the first part-body (26) in such a way that it bears radially sealingly against the main body (2) and against the first part-body (26) by the compressive force of the second part-body (27).Video endoscope according to one of Claims 5 to 7, characterized in that the first part-body (26) and the second part-body (27) are screwed to one another via a thread.Video endoscope according to one of the preceding claims, characterized in that the first part-body (26) comprises a second clamping nut (32) which compresses an elastic sealing element (31) arranged between the first part-body (26) and the enveloping tube (20).Video endoscope according to Claim 9, characterized in that the clamping ring (45) presses the anti-kink sleeve (35) against the second clamping nut (32).

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