WO2017174373A1

WO2017174373A1 - Video endoscope with shielded imaging unit and method for producing same

Info

Publication number: WO2017174373A1
Application number: PCT/EP2017/057053
Authority: WO
Inventors: Martin Wieters
Original assignee: Olympus Winter & Ibe Gmbh
Priority date: 2016-04-05
Filing date: 2017-03-24
Publication date: 2017-10-12
Also published as: DE102016205632A1

Abstract

The invention relates to a video endoscope (2) and to a method for producing same. The video endoscope (2) comprises an envelope tube (14) in which a fibre tube (18) extends, in which in turn an imaging unit (20) is arranged. The imaging unit (20) is enclosed on its outside by an outer tube (28). A grounded EMV layer (30) is present between the outer tube (28) of the imaging unit (20) and the fibre tube (18) and shields the imaging unit (20) electromagnetically. The outer tube (28) of the imaging unit is potential-free.

Description

Video endoscope with shielded imaging unit and method of making the same

description

The invention relates to a video endoscope with a shaft, comprising a cladding tube and a fiber tube extending in the cladding tube, wherein in the fiber tube an imaging unit is arranged, which is surrounded on its outer side by an outer tube. Furthermore, the invention relates to a method for producing such a video endoscope.

Video endoscopes are well known, especially in the field of medical technology. The shaft of a video-endoscope comprises a plurality of telescoped tubes. At a distal end of the shaft are often tools and mouths of working channels and a window for optics available. At the proximal end of the endoscope shaft there is a handle for operating the endoscope. The outside of the shaft often forms an outer cladding tube, in which a fiber tube is inserted. Within the fiber tube, an imaging unit is arranged, in which it is a video unit consisting of at least one lens and one image sensor, which is generally referred to as an R-unit.

The imaging unit is surrounded on its outside by an outer tube and is often hermetically encapsulated. The outer tube serves as an electromagnetic shield, which should also be referred to as EMC shielding. For this purpose, the outer tube of the imaging unit is contacted with ground. Opposite the fiber tube, the outer tube of the imaging unit must be electrically isolated. For this purpose, adhesive points or even along the circumference extending splices are provided, as well as one or more heat shrink tubing are used. However, these heat shrink tubes must be cut to fit the outer contour of the imaging unit and shrunk by heat on the imaging unit. In variable depth video endoscopes, the external geometry of the imaging unit is relatively complex. The moving parts of the optics with variable viewing direction also make the design complex. The isolation by means of one or more shrink tubing is often not possible or not profitable for practical reasons. In addition, the heat required for shrinking may have negative effects on the imaging unit. For example, it is possible for adhesive bonds to be loosened or weakened inside the imaging unit.

Furthermore, the smallest possible electrical capacity should be present between the fiber tube and the imaging unit. Too much capacity between these two components may result in excessive patient leakage current. In order to keep the capacity between the fiber tube and the imaging unit as low as possible, the imaging unit is often in a so-called Here, the diameter of the imaging unit tapers in the middle, but this is only possible because in this area no optics or other mechanically necessary parts are arranged, but ledigl I cable or a flexboard for electrical signal transmission in one However, the bone structure is expensive to manufacture and limits the assembly process in the manufacture of the imaging unit.

It is an object of the invention to provide a video endoscope and a method for producing a video endoscope, in which a reliable electromagnetic shielding of the imaging unit should be present, at the same time the design effort should be kept as low as possible.

The object is achieved by a video endoscope having a shaft comprising a cladding tube and a fiber tube extending in the cladding tube, wherein an imaging unit is arranged in the fiber tube, which is surrounded on its outside by an outer tube, wherein the video endoscope is developed by between the outer tube of the imaging unit and the fiber tube there is provided a grounded EMC layer adapted to electromagnetically shield the imaging unit, the outer tube being floating.

The EMC layer provides electromagnetic shielding of the imaging unit from an exterior space. The external space should be considered as a volume that is not covered by the imaging unit itself. The EMC layer is preferably a mechanically flexible layer. Furthermore, it is provided in particular that the EMC layer is a printed layer. Advantageously, the imaging unit is electromagnetically shielded from the outside by the EMC layer. With regard to the production of the video endoscope, it has proven to be technically easier and more efficient to arrange an additional component, namely the EMC layer, between the outer tube of the imaging unit and the fiber tube, as for example by adhesive dots or a circumferential adhesive trace the required electrical insulation between the units. Furthermore, it is advantageous that the geometry of the imaging unit can be made much simpler and in particular a complex structure, such as a bone structure, is dispensed with. Such geometries are not only easier to manufacture, but are also advantageous in terms of mounting the endoscope. For example, the imaging unit can be mounted from both sides in the fiber tube. Namely, the imaging unit does not comprise sections of different diameters, which in conventional units make such flexible mounting difficult or even impossible. Advantageously, the outer tube of the imaging unit is also potential-free.

According to one embodiment, the EMC layer is a discontinuous layer.

The EMC situation is particularly interrupted in sections or sections. In other words, it has openings or holes which can be uniformly distributed, that is to say in a regular arrangement, or irregular, that is to say they can be arranged statistically or pseudo-randomly or randomly. For example, the interrupted EMV position is a grid. If a film is provided as an EMC layer, this is, for example, a perforated foil. Likewise, it is provided in particular that the EMC layer is printed on the outer tube of the imaging unit. Also this printed Layer or layer is interrupted and has, for example, a hole or grid structure.

By interrupting the EMC layer, the contact area between the EMC layer and the outer tube of the imaging unit on the one hand and the EMC layer and the fiber tube on the other hand is reduced. This reduction in area leads to a reduction in the capacity between the outer tube of the imaging unit and the fiber tube. The insulation between these two components should be made as thin as possible for reasons of a small space. However, the capacitance between the components increases exponentially with the decrease of the gap. By interrupting the EMC situation, an effective measure is taken to counteract this effect. For one thing, the use of a very thin layer of film or film is possible, at the same time reducing or at least not increasing the capacity. Thus, space can be saved, at the same time the electrical properties are improved, but at least not be degraded. For effective electromagnetic shielding, it is not necessary to perform the shielding layer over the entire surface, continuously or continuously. The shield may have openings that are not greater than a quarter of the wavelength to be shielded. In other words, for example, the grid is smaller or the openings smaller in diameter than this critical size.

If a frequency of 1 GHz which is relevant for the electromagnetic shielding is assumed, the maximum hole size is 7.5 mm. For lower frequencies increase the wavelength and thus the permissible size of the openings.

For this reason, according to another embodiment, seen that the EMC layer has interruptions whose size does not exceed one quarter of a wavelength to be shielded, in particular does not exceed a size of 7.5 mm.

Furthermore, the EMC layer or the EMV film is more flexible due to its discontinuous design, for example when this is carried out as a grid, and can thus be easier and better assembled.

According to an advantageous embodiment, the video endoscope is formed by the fact that the EMC layer is composed of at least one electrically insulating layer and an electrically conductive layer, wherein in particular the outer tube made of electrically insulating material, further preferably made of plastic.

The electrically conductive layer is in particular a surface electrically conductive or conductive layer. It is coated, for example with Kapton, so that on its top or bottom an electrically insulating layer is present. The EMC layer is in particular a film. Accordingly, the aforementioned layers are single layers of this film. In other words, in particular, a two-layered film is used as the EMC layer.

According to a further embodiment, the EMC layer or the EMC film comprises a heating layer. Thus, it is possible to specifically heat the imaging unit and, for example, to prevent misting of the viewing window or remove existing hardware. The EMC layer is further adhered in particular to the outer tube of the imaging unit. For this purpose, for example, the layer or the film around the outer tube of the image wrapped unit and then glued or printed.

In particular, it is further provided that the EMC layer is contacted at a proximal end with a grounded component, in particular a component of a handle, of the video endoscope. This electrical contacting is in particular circumferential or approximately circumferential, ie. along the circumference or at least approximately along the full circumference of the EMC layer. For example, this electrical contacting is done by soldering.

Furthermore, according to a further embodiment, it is provided that the EMC layer extends in the distal direction along the shaft to at least one longitudinal position of an image sensor of the imaging unit. In other words, therefore, the EMC layer extends from the handle of the video endoscope to at least the longitudinal position of the image sensor, for example a CCD or CMOS sensor of the imaging unit. This is the most distal electrical shielding component. Preferably, in order to provide a reliable electromagnetic shield, the EMC layer projects slightly beyond the image sensor in the direction of the lengthwise direction of the shaft.

The EMC layer is in particular wound or laid on the outer tube of the imaging unit. Thus, it turns out that the outer edges of the EMC layer abut each other and either overlap slightly or a small gap or a narrow gap remains, if the size or the dimension of the EMC layer is not absolutely accurate. An overlap of the EMC layer may be provided to ensure a particularly reliable shielding. However, it is also possible to have one Gap, which does not exceed the aforementioned maximum extent to provide. So that this gap does not exceed the maximum permissible dimension in a direction parallel to the edge of the EMC layer, this edge is preferably serrated or wavy. The opposing edges thus have a corresponding mating wave or serrated shape.

Furthermore, the outer tube of the imaging unit is attached proximally, for example to the handle.

The object is further achieved by a method for producing a video endoscope according to one or more of the abovementioned aspects, wherein this method is developed in that

on an outer side of the outer tube of the imaging unit, the EMC layer is arranged so that the imaging unit is electromagnetically shielded and

the EMV layered imaging unit is placed in the fiber tube.

According to one embodiment, the EMC layer is contacted at a proximal end with a grounded component, in particular a component of a handle, of the video endoscope.

Furthermore, it is provided in particular that the outer tube is fastened proximally, for example on the handle.

The outer tube is mounted so that it is potential-free.

The same or similar advantages apply to the method as have already been mentioned with regard to the video endoscope itself, so that repetitions should be dispensed with. Further features of the invention will be apparent from the description of embodiments according to the invention together with the claims and the accompanying drawings. Embodiments of the invention may satisfy individual features or a combination of several features.

The invention will be described below without limiting the general inventive idea by means of embodiments with reference to the drawings, reference being expressly made to the drawings with respect to all in the text unspecified details of the invention. Show it:

Fig. 1 a video endoscope in a simplified perspective view,

Fig. 2 shows a simplified schematic view of a longitudinal section through the shaft of the video endoscope in its distal end region,

Fig. 3 shows a schematically simplified perspective view of a longitudinally cut shaft of the video endoscope in its grip area,

Fig. 4 shows a schematically simplified view of a cross section through the shaft of a video endoscope and

Fig. 5 is a simplified schematic plan view of a detail at a seam or joint of the EMC layer.

In the drawings, the same or similar elements and / or parts are provided with the same reference numerals, so that of a renewed presentation is omitted in each case.

Fig. 1 shows a video endoscope 2 comprising a shaft 4 and a handle 6. The shaft 4 is connected at its proximal end 8 with the handle 6. At the distal end 10 of the shaft 4 there is a viewing window 12 through which an examination or operating area lying in front of the distal end 10 is observed (not visible) with an imaging unit present in the interior of the shaft 4. The imaging unit is a video unit, also commonly referred to as an R-unit. The shaft 4 of the video endoscope 2 comprises a plurality of telescoped tubes. The outside of the shaft 4 is a cladding tube 14, which comes into direct contact with the patient during use of the video endoscope 2.

Fig. FIG. 2 shows a section-wise, simplified and schematic view of a longitudinal section through the shaft 4 of the video endoscope 2 in its distal end region, ie in the vicinity of the distal end 10. The shaft 4 has the cladding tube 14 on its outside. The cladding tube 14 encloses a fiber bundle 1 6, which is led to illuminate the observation or surgical field, starting from a lighting unit, not shown, to the distal end 1 0 of the video endoscope 2. Within the cladding tube 14 is also a fiber tube 1 8, in which an imaging unit 20 is arranged. The exemplified imaging unit 20 comprises a lens 22 with a plurality of lenses and an image sensor 24, for example a CCD or CMOS chip, to which a contacting unit 26 of the imaging unit 20 is connected. The imaging unit 20 is surrounded on its outer side by an outer tube 28.

Between the outer tube 28 of the imaging unit 20 and the Fiber tube 1 8 an EMC layer 30 is present. The EMC layer 30 is grounded, that is electrically connected to ground. The EMC layer 30 is further configured to shield the imaging unit 20 electromagnetically from an exterior space. The EMC layer is in particular a discontinuous layer. The outer tube 28 of the imaging unit 20 is in particular made of plastic. Selbstverliel I can also be another electrically insulating material or a non-electrically insulating insulating material, such as a metal, may be provided for the outer tube 28. The outer tube 28 has no potential, it is, if made of an electrically conductive material, grounded proximal. If it is made of an electrically insulating material, such as a plastic, no electrical insulation is necessary. In this case, the outer tube 28 is also not grounded. In other words, the outer tube 28 is potential-free. It is also attached proximally.

The EMC layer 30 is preferably constructed from one or two layers. It includes on its flat outer sides, ie on its flat side, which faces the outer tube 28 of the imaging unit 20, or on its outer side, which faces the fiber tube 18, an electrically insulating layer. If the outer tube 28 made of an electrically insulating material, so no electrically insulating layer is necessary. An electrically conductive layer is covered by an outer electrically insulating layer, in particular completely. The electrically conductive layer is in particular a surface electrically conductive layer. The EMC layer 30 is preferably a film. In other words, therefore, a single-layer or two-layer film is provided as the EMC layer 30. It is, for example, a Kapton-coated conductive foil, eg a thin metal foil. Likewise, it is provided that the EMC layer 30 is applied to the outer tube 28 of the image giving unit 20 is printed. The outer tube 28 of the imaging unit 20 is in particular a plastic tube. The printed EMC layer 30 is also interrupted, for example, has a hole or grid structure.

Furthermore, according to one exemplary embodiment, it is provided that the EMC layer 30 comprises a heating layer. Thus, it is possible for me to specifically heat the imaging unit 20 and to prevent misting of the viewing window 1 2 present at the distal end 10 of the video endoscope 2 (see FIG. The EMC layer 30 is further bonded in particular to the outer tube 28 of the imaging unit 20.

Fig. 3 shows, in a schematically simplified perspective view, the longitudinally cut shaft 4 of the video endoscope 2 in the region of the handle 6. Shown is a grip body 32 which extends in the interior of the device shown in FIG. 1 shown handle 6 of the video endoscope 2 is located. In the handle body 32, the outer tube 28 of the imaging unit 20 is received, wherein the outer tube 28 if necessary relative to the handle body 32 can electrically isolate through the EMC layer 30. In Fig. 3, for example, an actuating tube 34 is shown, which passes through the outer tube 28 centrally and extends to the imaging unit 20. The actuating tube 34 is provided to rotate or rotate the image sensor 24, thus tracking a change in the viewing angle of the video-endoscope 2.

At the in Fig. 3 shown proximal end 8 of the shaft 4 d he EMC layer 30 with a grounded component, in the illustrated embodiment with the handle body 32, electrically contacted. For this purpose, for example, a solder joint is provided in the throat 36 between an end face 38 of the grip body 32 and the EMC layer 30. hen. This solder connection preferably extends along the entire circumference of the EMC layer 30. In order to produce a reliable electrical contact with the conductive layer of the EMC layer 30, for example locally in the region of the throat 36, if present, the outer insulating layer of the EMC Location 30 away or at least partially interrupted.

The EMC layer 30 extends from the handle 6 or from the grip body 32 of the video endoscope 2 in the distal direction D along the shaft 4 at least up to a longitudinal position of the image sensor 24 of the imaging unit 20. In other words, that means in Fig. 2, the EMC layer 30 extends distally D to at least the image sensor 24 of the imaging unit 20, preferably as shown above.

According to one embodiment, the EMC layer 30 is a discontinuous layer. It is interrupted sections or sections, so has openings or holes. The openings or holes are for example uniformly distributed, that is arranged regularly or irregularly, for example statistically, pseudo-randomly or randomly. For example, the EMC layer 30 is a grid, grid-shaped or, if the EMC layer 30 is realized as a film, a grid or perforated film. Due to the interruptions, the EMC layer 30 becomes more flexible, so that it can be processed more easily, for example, it can be more easily placed around the outer tube 28 of the imaging unit 20 and fixed there.

The interruption of the EMC layer 30 also reduces the electrical capacitance between the outer tube 28 of the imaging unit 20 and the fiber tube 18. The capacity between these two components increases with decreasing distance between the two components Components, but it falls with the area occupied by the components of the EMC layer 30. In order to keep the necessary space as small as possible, the EMC layer 30 should be made as thin as possible. With decreasing thickness or material thickness of the EMC layer 30, however, the electrical capacitance between the outer tube 28 and the fiber tube 1 8 increases. The interruption of the EMC layer 30 counteracts this effect. Thus, space can be saved, at the same time the capacity between the outer tube 28 and the fiber tube 1 8 is reduced. A small capacity between the two components is important in order to counteract an excessive patient leakage current.

The existing in the EMC layer 30 openings or a grid can be chosen so large that the desired cutoff frequency is still reliably shielded. If, for example, a frequency of 10 GHz which is relevant for the electromagnetic shielding is assumed, the maximum hole size can be 7.5 mm. Openings or breaks in the EMC layer 30 may be provided which are not greater than a quarter of the cut-off wavelength to be shielded.

Furthermore, it is possible not to completely guide the EMC layer 30 along the circumference around the fiber tube 28. This is shown in FIG. 4 in a schematically simplified view of a cross section through the shaft 4 of the video endoscope 2. The outer tube 28 of the imaging unit 20 and the EMC layer 30 are shown. The EMC layer 30 is dimensioned such that its abutting edges keep a distance d. This distance d is smaller than the aforementioned critical size for the interruptions of the EMC layer 30. For example, d is less than 7.5 mm.

Thus, this gap represents the effectiveness of the EMC layer 30 as an electrical magnetic shielding is out of the question. Thus, even in the longitudinal direction of the shaft 4 d he dimension of this gap is not greater than the intended critical size, the outer edges of the EMC layer 30, which face each other in the joint area, for example, serrated or wavy. This is shown in FIG. 5 in a schematically simplified plan view of a seam or joint of the EMC layer 30.

The above explanations apply to all versions of the EMC layer 30. They therefore cover both the case where the EMC layer 30 is designed as a foil and the case where the EMC layer 30 is designed as a printed layer.

In a method for producing a video endoscope 2 according to one or more of the aforementioned exemplary embodiments, the EMC layer 30 is arranged on the outside of the outer tube 28 of the imaging unit 20. It is glued there, for example. Subsequently, the imaging unit 20 provided with the EMC layer 30 is arranged in the fiber tube 18. The EMC layer 30 is also contacted at a proximal end with a grounded component, for example a component of the handle 6 of the video endoscope 2, so that the imaging unit 20 is shielded electromagnetically.

All these features, including the drawings to be taken alone as well as individual features that are disclosed in combination with other features are considered alone and in combination as erfindungswesentl I. Embodiments of the invention may be accomplished by individual features or a combination of several features. In the context of the invention, features which are identified by "particular" or "preferably" are to be understood as optional features. LIST OF REFERENCE NUMBERS

2 video endoscope

4 shaft

6 handle

8 proximal end

10 distal end

1 2 viewing window

14 cladding tube

16 fiber bundles

1 8 fiber tube

20 imaging unit

22 lens

24 image sensor

26 connection unit

28 outer tube

30 EMC position

32 handle body

34 actuating tube

36 throat

38 front side d distance

D distal direction

Claims

Video endoscope with shielded imaging unit and method of making the same claims

1 . A video endoscope (2) with a shaft (4) comprising a cladding tube (14) and a fiber tube (1 8) extending in the cladding tube (14), wherein in the fiber tube (18) an imaging unit (29) is arranged on its Outside of an outer tube (28) is surrounded, characterized in that between the outer tube (28) of the imaging unit (20) and the fiber tube (1 8) a grounded EMC layer (30) is provided, which is adapted to shield the imaging unit (20) electromagnetically, wherein the outer tube (28) is floating.

2. video endoscope (2) according to claim 1, characterized in that the EMC layer (30) is a discontinuous layer.

3. Video endoscope (2) according to claim 1 or 2, characterized in that the EMC layer (30) of at least one electrically insulating layer and an electrically conductive layer is joined together, wherein in particular the outer tube (28) made of an electrically insulating material, further preferably made of plastic.

Video endoscope (2) according to one of claims 1 to 3, characterized in that the EMC layer (30) is contacted at a proximal end with a grounded component, in particular a component of a handle (6) of the video endoscope (2).

Video endoscope (2) according to one of claims 1 to 4, characterized in that the EMC layer (30) in the daler direction (D) along the shaft (4) to at least a longitudinal position of an image sensor (24) of the imaging unit (20) extends.

Video endoscope (2) according to one of claims 1 to 5, characterized in that the EMC layer (30) has interruptions whose size does not exceed one fourth of a wavelength to be shielded, in particular does not exceed a size of 7.5 mm.

Method for producing a video endoscope (2) according to one of Claims 1 to 6, characterized in that the EMC layer (30) is arranged on an outer side of the outer tube (28) of the imaging unit (20), so that the imaging unit ( 20) is electromagnetically shielded and

the imaging unit (20) provided with the EMC layer (30) is arranged in the fiber tube (18). A method according to claim 7, characterized in that the EMC layer (30) at a proximal end with a grounded component, in particular a component of a handle (6), the video endoscope (2) is contacted.

A method according to claim 7 or 8, characterized in that the outer tube (28) is fastened proximally.