Endoscope with a rigid curved shaft as well as process for producing such an endoscope

An endoscope is provided, with a main body and a rigid shaft, extending from the main body, which has a first section which extends in a rectilinear manner, a curved second section adjoining it and a third section, adjoining the second section, which forms a distal end of the shaft. The shaft includes, for receiving an instrument, a one-piece instrument tube which extends to the distal end of the shaft and has an open end there, and an optics module by means of which an image of an area in front of the distal end of the shaft can be recorded. A cladding tube extending from the main body to the distal end is provided, in which the instrument tube and the optics module are arranged, and which includes a rectilinear part for the first section and a curved part, connected to the rectilinear part, for the second section.

PRIORITY

This application claims priority to German Patent Application No. 102013207109.4, filed on Apr. 19, 2013, which is hereby incorporated herein by reference in its entirety.

FIELD

The present invention relates to an endoscope with a rigid curved shaft as well as a process for producing such an endoscope.

BACKGROUND

Endoscopes are used for example in the medical field, e.g. for carrying out examinations and optionally treatments in the area of the nose. For this purpose, as a rule, such endoscopes have a curved instrument tube with an open distal end and a correspondingly curved optics tube. An image of the corresponding area in front of the distal end is recorded via the optics tube and an instrument can be positioned at the corresponding point via the instrument tube, for example to remove tissue. The optics tube and the instrument tube are connected to one another and can have several parts, with the result that the rigid shaft formed by the two tubes does not have a smooth outer surface but has recesses and edges. This is disadvantageous as dirt can collect there, with the result that it is difficult to clean and sterilize the endoscope.

SUMMARY

An object of certain embodiments of the invention is to provide an endoscope, with a rigid curved shaft, which has an instrument tube for receiving an instrument as well as an optics module for recording an image of an area in front of the distal end of the shaft and which can be easily cleaned.

According to certain embodiments, the object is achieved by an endoscope including a main body and a rigid shaft, extending from the main body, which includes a first section which extends in a rectilinear manner, a curved second section adjoining it and a third section, adjoining the second section, which forms a distal end of the shaft, wherein the shaft includes, for receiving an instrument, a one-piece instrument tube which extends to the distal end of the shaft and has an open end there, and an optics module by means of which an image of an area in front of the distal end of the shaft can be recorded, and wherein a cladding tube extending from the main body to the distal end is provided, in which the instrument tube and the optics module are arranged and which has a rectilinear part for the first section and a curved part, connected to the rectilinear part, for the second section.

The cladding tube can provide the shaft with a smooth outer surface on which on the one hand dirt cannot collect and which on the other hand is easy to clean. Since the cladding tube is formed of several parts, the endoscope according to certain embodiments is also easy to produce. In particular, the already curved instrument tube can be inserted with its curved section into the curved part and a rectilinear section of the instrument tube can be inserted into the rectilinear part. The two parts can then be connected to one another, resulting in the desired cladding tube.

The instrument tube in one preferred embodiment does not protrude out of the distal end of the cladding tube. In particular the distal end of the instrument tube can be flush with the distal end of the cladding tube.

The optics module can be inside the cladding tube and preferably does not protrude beyond the distal end.

The end of the curved part which faces away from the rectilinear part can form the distal end of the shaft. Alternatively it is possible for the cladding tube to have a third part which forms the distal end of the shaft and is connected to the curved part. The third part can in particular be produced from a solid material by machining, whereas the first and second parts can preferably be produced from a hollow tube, in particular an extruded hollow tube. The parts forming the cladding tube are preferably produced from stainless steel.

The parts which are connected to one another can be welded to one another. The weld points are preferably ground subsequently, with the result that the cladding tube has a smooth continuous outer surface.

The third part can be formed in one piece and have an end plate which seals the end facing away from the curved part, wherein an opening for the instrument tube and at least one opening for the optics module are provided in the end plate.

The at least one opening for the optics module in the end plate can be sealed by means of a transparent disc or plate. In particular it can be a glass sheet or glass disc (for example sapphire glass). The glass can be soldered to seal the opening hermetically.

The curved part can have a curvature of greater than 0° and smaller than 120°, in particular a curvature of greater than or equal to 10° and smaller than or equal to 110°. Furthermore, the curvature can lie in the range of from 10° to 100°, 10° to 90°, 20° to 120°, 30° to 120° or 45° to 120°.

The optics module can in particular embodiments be arranged at the distal end in the shaft. The optics module can have at least one imaging lens system (e.g. objective lens). Furthermore, the optics module can have an image sensor, such as e.g. a CMOS or CCD sensor, arranged directly behind the imaging lens system. Alternatively a transmission lens system, which transmits the recorded image into the main body, can be arranged downstream of the imaging lens system. An image sensor can be arranged in the main body to record the transmitted image. Alternatively or in addition an optical view device can be provided on the main body via which a user can see the image transmitted into the main body.

Furthermore, the endoscope according to certain embodiments of the invention can include an illumination system which illuminates the recordable area via the distal end. The illumination system can for example have a light source at the distal end. Alternatively, the light source can be arranged in the main body. To transmit the light of the light source for example an optical fibre can be used which then runs from the main part via the shaft to the distal end. The light source can in particular be a light-emitting diode or a laser diode. The light source preferably emits light in the visible spectral range. Alternatively or in addition it can also emit light in other wavelength ranges such as e.g. in the infrared range.

It is possible for the endoscope itself not to have a light source, but to have only an optical fibre connection on the main body via which light from an external light source can then be guided to the distal end.

The instrument tube in certain preferred embodiments has a cross-section shape which comprises, in addition to an area with a circular cross-section, also a further area. This further area can then, with an inserted instrument which occupies the area with the circular cross-section, be used as an irrigation and/or suction channel. In particular, the instrument tube can have a D-shaped cross-section.

The cladding tube can include an elongated cross-section shape which has two rounded ends lying opposite one another as well as two sides which connect the ends and extend in a rectilinear manner. The rounded ends can in particular have a curve with a constant radius and in particular a semi-circular curve. The sides which extend in a rectilinear manner can in particular be parallel to one another.

As already stated, it is possible to arrange in the main body a light source, the light of which is guided via an optical fibre system to the distal end to illuminate the recordable area in front of the distal end.

The light source can be in direct mechanical contact with a first heat-conducting body which conducts heat generated by the light source to a housing wall of the main body, wherein the thermal conductivity of the first heat-conducting body is greater than that of the housing wall. Thus the housing wall can be produced for example from stainless steel and the first heat-conducting body can be produced from aluminum.

In the endoscope according to certain embodiments of the invention it is possible to arrange in the main body at least one further heat-conducting body which is in thermal contact with the first heat-conducting body and is loaded with a force which pushes it against the inside of the housing wall. In particular, two further heat-conducting bodies can be arranged which lie opposite one another. The two heat-conducting bodies can be pushed away from one another. For this purpose a screw can be used, for example, which is guided into an internal thread at least in one of the two heat-conducting bodies. The end of the screw which faces away from the internal thread can push against the other heat-conducting body. By setting the screw appropriately the two heat-conducting bodies can be pushed away from one another.

In the endoscope according to certain embodiments of the invention the thermal contacting of the heat-conducting body with the housing wall can be generated purely by touch without thermal adhesive or thermal conducting paste. Alternatively it is possible to use a thermal adhesive or a thermal conducting paste.

In the endoscope according to certain embodiments of the invention the main body and the shaft except for the instrument tube can be hermetically sealed with respect to the surroundings and can thus be autoclavable. Here, by autoclavable is meant in particular that the endoscope is exposed, for a specified period (for example several minutes), to water vapor (in particular saturated water vapor) of from at least 100° C. or at least 130° C. for sterilization, without the endoscope being damaged (in particular without water vapor being able to penetrate the shaft (except for the instrument tube) and the main body).

The object can be furthermore achieved in certain embodiments by a process for producing an endoscope according to the invention in which the following steps are carried out:

a) inserting a curved section of the instrument tube into the curved part,

b) inserting a rectilinear section of the instrument tube into the rectilinear part, and

Steps a) and b) can be carried out in any order. The connecting according to step c) can for example be carried out by welding.

The process according to certain embodiments of the invention can feature the step of bending the instrument tube. Furthermore it can feature the step of bending a rectilinear hollow tube to produce the curved part.

The process according to certain embodiments of the invention can include the process steps described in connection with the endoscope according to the invention including developments thereof. Furthermore it can include the process steps to produce the endoscope according to the invention including developments thereof.

It is understood that the features mentioned above and those yet to be explained below can be used, not only in the stated combinations, but also in other combinations or singly, without departure from the scope of the present invention.

DETAILED DESCRIPTION

The present invention can be explained with reference to the following example embodiments. However, these example embodiments are not intended to limit the present invention to any specific examples, embodiments, environments, applications or implementations described in these embodiments. Therefore, description of these embodiments is only for purpose of illustration rather than to limit the present invention.

Referring toFIG. 1, the endoscope1comprises a main body2and a rigid shaft3connected to it, which is bent at the distal end4facing away from the main body2. Because of the rigid formation of the shaft, this bending cannot be changed.

The rigid shaft3includes a first rectilinear section5, connected to the main body2, which is adjoined by a second curved section6. A third section7which forms the distal end4of the shaft3adjoins the second section6.

The main body3includes a main part8, to which the shaft3is connected, as well as a handle9.

As can be seen most clearly from the sectional representation according toFIG. 2, the shaft3comprises a cladding tube10, which extends from the distal end4into the main part8. In the cladding tube10an instrument tube11is arranged which extends to the distal end4and has an open end12there. Although the distal end of the cladding tube10is sealed with an end plate60(FIG. 3), the end plate60has an opening61for the instrument tube11, with the result that the open end12is accessible from the outside. The instrument tube11, which is formed in one piece and thus has no interruptions, extends from the distal end4through the main part8of the main body2and opens in a connecting sleeve13. An instrument can be inserted into the instrument tube11via the connecting sleeve13and pushed to the distal end4and beyond, as the instrument tube11has the open end12at the distal end4.

In addition, provided in the cladding tube10there is an optics channel14which, as is described in detail below, serves to be able to illuminate an area in front of the distal end4and record an image of the illuminated area.

To illuminate the area in front of the distal end4, in the main part8in a baseplate16made of aluminum a light-emitting diode15is positioned which emits illumination light which is coupled into an optical fibre17positioned in front of the light-emitting diode15. For this purpose one end of the optical fibre17is positioned directly in front of the light-emitting diode15via a holder18.

The optical fibre17extends from the light-emitting diode15through the inside of the main part8into the optics channel14of the cladding tube10and runs inside this to the distal end4. As the end plate60has two illumination openings20,21, as can be seen most clearly inFIG. 3in which a top view of the distal end4is shown, after passing through the second curved section6of the shaft3the optical fibre17divides at a branching point19into two optical fibre sections which run to the two illumination openings20,21. In the representation according toFIG. 2the two optical fibre sections therefore run towards the front and towards the back out of the plane of drawing according toFIG. 2. In the sectional representation according toFIG. 2the optical fibre17therefore seems to end at the branching point19.

The two illumination openings20,21are each hermetically sealed with a cover glass22,23(FIG. 3). In the end plate60in the distal end4between the two illumination openings20and21a further opening24is formed, which is again hermetically sealed with a cover glass25. The recording of the image of the illuminated area in front of the distal end4takes place via this opening24. For this purpose a recording module26is arranged behind the cover glass25in the optics channel14. This can be seen particularly well in the sectional representation ofFIG. 4in which detail A fromFIG. 2is represented enlarged.

The recording module26comprises, behind the cover glass25, an objective lens27and an image sensor28(which is here formed as a CMOS sensor) which sit in a holder29which serves to position the objective lens27and the image sensor28behind the cover glass25. Furthermore a cable24(here ribbon cable) is also represented schematically inFIG. 4which is connected to the image sensor28and runs from the image sensor28via the optics channel14to a corresponding electronic control unit, of which one of two circuit boards31is drawn schematically inFIG. 2, in the handle9. To simplify the representation the cable30shown ends before the curved second section6.

The cladding tube10is formed here of three parts32,33and34which are welded to one another at the points35and36. The first part32forms the straight section5. The second part35forms the curved second section6and the third part34, together with the second part33, forms the third section7of the shaft3. The second part35can have an area at each of its two ends which extends in a straight line and then forms part of the first or third section5,7. The curved second part33is here curved such that an angle α between the longitudinal direction of the third section7and the longitudinal direction of the first section5is 70°. The angle α is preferably greater than 0° and smaller than or equal to 120°. In particular, the angle α is greater than or equal to 10° and smaller than or equal to 110°.

This formation of the cladding tube10in several parts allows the endoscope1according to the invention or the shaft3of the endoscope1according to the invention to be easy to produce. Thus, to produce the endoscope1the one-piece instrument tube11with its distal end is pushed through the curved second part33until the curved section of the instrument tube11rests against the correspondingly curved second part33on the inside. Then the third part34is pushed on from the distal end side and the first part32from the proximal end side. The first part32is then welded to the second part33at the point35and the third part34is welded to the second part33at the point36.

Of course, the order in which the third and first parts34,32are pushed on can also be reversed. Furthermore the welding can also be carried out at the point36first and then at the point35. Finally, it is also possible to carry out the corresponding welding after pushing on the first or third part32,34, and then to push on and weld the remaining part (third or first part34,32).

Before the third part34is pushed onto the instrument tube11, the recording module26as well as the ends of the optical fibre sections of the optical fibre17can be secured in the third part34. Furthermore, the cover glasses22,23and25can also already be inserted. The cover glasses22,23and25are preferably soldered, with the result that they hermetically seal into the corresponding opening20,21,24. Finally, the instrument tube11is also soldered or welded in the distal end to the corresponding opening61in the end plate60, with the result that a hermetically sealed connection is also present here in such a way that fluid can indeed flow into the instrument tube11or out of the instrument tube11via the open end12of the instrument tube11. However, there is no connection from the instrument tube11or the inside of the instrument tube11to the optics channel14or to the inside of the main body2. Both the optics channel14and the main body2are thus hermetically sealed with respect to the surroundings.

As can be seen in particular from the representation inFIG. 3, the instrument tube11has a substantially D-shaped cross-section. It is thus advantageously achieved that when an instrument37is arranged in the instrument tube11, as is indicated by the dashed circle inFIG. 3, in the instrument tube11there are still two free areas38,39which can be used for rinsing and/or suction. A rinsing fluid can be fed, via these areas38,39, to the area in front of the distal end4. Furthermore, corresponding material can be suctioned off via these areas38,39. As indicated inFIG. 1, for this purpose it is possible to provide on the connecting sleeve13a T-shaped connecting element40which provides a means of access41for the instrument to be inserted on the one hand and has a suction/irrigation connection42on the other hand. The connecting element40is drawn in only inFIG. 1and not inFIG. 2. This rinsing facility makes it possible to remove e.g. dirt from in front of the cover glass25,22and/or23while using the endoscope1, with the result that permanently good recording conditions for the recording module26can be created and maintained.

The D-shaped cross-section of the instrument tube11leads to the already described advantage that with an inserted instrument37there are still free areas38,39which can be used as irrigation and/or suction channel. Moreover, the D-shaped cross-section is extremely compact, with the result that the cross-section of the cladding tube10can also be kept as small as possible. In addition to the D-shaped cross-section of the instrument tube11other cross-section shapes are, of course, also possible, which are preferably selected such that in addition to a circular cross-section area (here for the instrument37) there is still at least one free area (here areas38and39) which can be used as irrigation and/or suction channel.

In order that the cladding tube10can receive the instrument tube11it does not have a circular cross-section but rather a cross-section which deviates from the circular and which can for example be called a double-D cross-section. The cross-section therefore has two curved (here semi-circular) ends62,63which are connected by rectilinear sides64,65which e.g. run parallel to one another (FIG. 3). In order to be able to better represent this cross-section shape of the cladding tube10in the perspective view inFIG. 1, two auxiliary lines L1, L2, extending in the longitudinal direction of the cladding tube, are drawn in which illustrate the transition of the two ends62,63to the rectilinear side65. In addition, another auxiliary line L3is drawn in which indicates the transition from the curved second section6to the third section7extending in a rectilinear manner.

The circuit boards31arranged in the handle9serve to control the image sensor28as well as the light-emitting diode15. The circuit boards31are arranged in the handle9between a first and a second heat-conducting body43and44. This can be seen in particular inFIG. 5which shows a sectional representation along the section line B-B ofFIG. 2. The heat-conducting bodies43,44have flat insides45,46facing towards one another. The outer sides of the two heat-conducting bodies43and44are adapted to the internal contour of the hollow cylinder-shaped wall section47of the handle9. Both the first and the second heat-conducting bodies43,44each have a protruding section48,49which project into the main part8and rest in each case against the corresponding inside50,51of a third heat-conducting body53which rests with its outer side against the substantially hollow cylinder-shaped wall section54of the main part8. The third heat-conducting body53has a substantially U-shaped cross-section. The third heat-conducting body53is in contact with the base16, as can be seen clearly inFIG. 2.

The protruding section48of the first heat-conducting body43has an internal thread55in which a screw56is screwed, the end of which facing away from the internal thread55pushes against the protruding section49of the second heat-conducting body44. The screw56is screwed into the internal thread55such that the two protruding sections48,49are pushed away from one another and thus against the insides50,51of the third heat-conducting body53. Thus a surface contact exists between the protruding sections48and49and the third heat-conducting body53. This also leads to the third heat-conducting body53being pushed against the inside of the hollow cylinder-shaped wall section54. Furthermore, the spreading of the two protruding sections48,49by means of the screw56leads to the first and second heat-conducting bodies43and44resting well against the hollow cylinder-shaped wall section47.

The heat-conducting bodies43,44and53as well as the base16are produced from aluminum, have a high thermal conductivity or a higher thermal conductivity than the wall sections47and54and serve to convey the heat forming during the operation of the light-emitting diode15to the hollow cylinder-shaped wall sections47and54over a large surface area and thus to dissipate it towards the outside. The heat-conducting bodies43,44and54thus serve to spread the heat. The hollow cylinder-shaped wall sections47and54are produced from stainless steel and have a significantly lower thermal conductivity than the heat-conducting bodies43,44and53. However, due to the contact over a large surface area, the heat dissipation can be ensured.

The contact between the individual heat-conducting bodies43,44and53is ensured by the spreading of the two protruding sections48and49and the contact of the heat-conducting bodies43,44and53with the corresponding wall sections47and54is ensured by the application of force, which is the result of the spreading. If necessary and/or desired, the heat-conducting bodies43,44and54and the base16can be adhesively secured to one another and/or to the corresponding wall sections47and54.

At the lower end of the handle9a cable57is also drawn in inFIG. 1which serves on the one hand to supply power to the light-emitting diode15, the circuit boards31and the image sensor28. On the other hand, the image data of the images recorded by means of the image sensor28are delivered to the outside via the cable57. For this purpose, for example, a connector (not shown) is provided at the end of the cable57.

The entire endoscope1, except for the instrument tube11, is formed to be hermetically sealed with respect to the surroundings. In particular the optics channel14and the main body2are hermetically sealed with respect to the surroundings and the inside of the instrument tube11. For this purpose the cladding tube10as well as the wall parts of the main body are here produced from stainless steel. The connection points to be sealed are preferably welded. Thus the endoscope1is autoclavable.

As the instrument tube11is formed in one piece and thus has no interruptions, the endoscope1can be cleaned and sterilized very well in an autoclave process.

The formation of the cladding tube10in several parts thus makes it possible to provide an endoscope, with a rigid shaft3the end of which is bent, in which the outer contour of the shaft3is smooth and has no edges, recesses, undercuts or projections on which dirt can easily collect. The weld points35and36can be ground down such that there is no bump but rather the cladding tube10has a smooth outer surface.

The first and second parts32and33of the cladding tube are preferably produced from hollow tubing. This can in particular be tubing produced by drawing. Such tubing can be bent well. The third part36is preferably produced from a solid material by machining. The distal end4and in particular the end plate60with the openings20,21,24and61can thus be produced well. In particular, the openings20,21and24can be produced such that the respective cover glass22,23and25in the inserted state is flush with the upper side of the upper plate60. In addition, a corresponding seat66can be formed for the optics module26(FIG. 4).

The endoscope1according to the invention is in particular formed as an endoscope for use in the medical field. Furthermore it can serve as an endoscope1for use in the ear, nose and throat field.