DE102019113659A1 - endoscope - Google Patents

Abstract

The invention relates to an endoscope with a hollow instrument shaft (1), at least one image recording unit (2) and at least one lighting unit (3) for illuminating an examination area to be viewed by means of the at least one image recording unit (2) being arranged in the instrument shaft (1). In order to create an endoscope in which the image recording unit (2) and the lighting unit (3) are arranged within the instrument shaft (1) in such a way that, on the one hand, a high image recording quality is guaranteed and, on the other hand, the examination area is sufficiently illuminated by the lighting unit (3), It is proposed according to the invention that the at least one lighting unit (3) viewed in the direction of the longitudinal axis (7) of the instrument shaft (1) is arranged on the proximal side in front of the at least one image recording unit (2) in the instrument shaft (1) and that in the instrument shaft (1) at least one optical system (8) is arranged, via which the light emitted by the at least one lighting unit (3) can be fed to the examination area.

Description

The invention relates to an endoscope with a hollow instrument shaft, with at least one image recording unit and at least one lighting unit for illuminating an examination area to be viewed by means of the at least one image recording unit being arranged in the instrument shaft.

Endoscopes with an image recording unit arranged on the distal side are known from practice in particular as video endoscopes in the most varied of designs. As a rule, the video endoscopes have an image recording unit arranged as centrally as possible in the distal end of the instrument shaft, around which a lighting unit in the form of LEDs or fiber optic cables is arranged. The examination area is illuminated with the aid of the illumination unit, which generally emits in the viewing direction of the image recording unit.

Due to the limited spatial relationships within the generally circular cross-section of the instrument shaft, a compromise must always be found between the size of the image recording unit and the size of the lighting unit in order to obtain sufficiently good image quality with good illumination of the examination area. The more space is available for the image recording unit, the higher-resolution sensors with better optics can be built into the instrument shaft.

Based on this, the invention is based on the object of creating an endoscope in which the image recording unit and the lighting unit are arranged within the instrument shaft in such a way that, on the one hand, a high image recording quality is ensured and, on the other hand, the examination area is sufficiently illuminated by the lighting unit.

The solution to this problem is characterized according to the invention in that the at least one lighting unit, viewed in the direction of the longitudinal axis of the instrument shaft, is arranged on the proximal side in front of the at least one image recording unit in the instrument shaft and that at least one optical system is arranged in the instrument shaft via which the at least light emitted by a lighting unit can be fed to the examination area.

By displacing the at least one lighting unit on the proximal side in front of the at least one image recording unit according to the invention, a much larger part of the instrument shaft cross section can be used for the image recording unit, which allows the use of higher-resolution sensors and better optics. In order to still be able to feed the light of the at least one lighting unit to the examination area, the at least one optical system is additionally arranged in the instrument shaft, which guides the light emitted by the lighting unit in the direction of the examination area.

With a first embodiment of the invention it is proposed that the at least one optical system is designed as a reflector unit which feeds the light emitted by the lighting unit to the examination area by means of mirrors. For this purpose, for example, an annular gap around the centrally arranged image recording unit can be used.

According to an alternative second embodiment for forming the optical system, it is proposed according to the invention that the at least one optical system is designed as a lens system. This lens system can for example be arranged in an annular gap around the centrally arranged image recording unit and deflect the light into the examination area.

According to a practical embodiment of the invention, it is proposed that an area of the instrument shaft in the area of the lighting unit is designed to be radially expandable in cross section in order to guide the light emitted by the lighting unit to the examination area. Due to the radially expandable area of the instrument shaft, it is possible via the cross-sectional enlargement to guide the light from the lighting unit past the image recording unit to the examination area.

According to a first embodiment of the invention, the radial expansion of the instrument shaft takes place mechanically via a rack gear or articulated rod mechanism. These mechanical possibilities to radially expand the instrument shaft are easy to manufacture and easy and reliable to use during operation.

According to an alternative second embodiment, it is proposed that the radial expansion of the instrument shaft takes place pneumatically by generating an overpressure in the interior of the instrument shaft. This embodiment can be implemented, for example, by a pressure cartridge arranged at the proximal end of the instrument shaft, which increases the pressure in the interior of the instrument shaft, which in turn allows the instrument shaft to expand radially.

As a third variant of the radial expansion of the instrument shaft, it is proposed according to the invention that the radial expansion of the instrument shaft takes place thermally, namely through the use of memory metals for the expandable area of the instrument shaft. For this purpose, the expandable area of the instrument shaft would then be designed in such a way that it would be folded in with the supply of heat and, when the supply of heat was switched off, it would merge into the radially expanded form that enlarges the shaft cross-section.

In order to make the radially expandable area of the instrument shaft structurally simple on the one hand and to ensure good light guidance on the other hand, the invention proposes that the radially expandable area of the instrument shaft in the expanded state is spherical or pyramidal in longitudinal section.

With a preferred embodiment of the invention it is further proposed that the inside of a sub-area of the radially expandable area arranged on the proximal side in the expanded state of the radially expandable area of the instrument shaft is designed to be reflective forming the reflector unit and that a distal side of the radially expandable area of the instrument shaft in the expanded state arranged portion of the radially expandable area is translucent. This embodiment of the reflector unit according to the invention makes it possible in a simple manner to direct the light emitted by the lighting unit along the outside of the instrument shaft in a distal direction towards the examination area.

Furthermore, it is proposed with the invention that the surface of the inside of the proximally arranged partial area of the radially expandable area is stepped, in particular in the manner of a Fresnel step lens. This design of the surface of the reflector unit makes it possible to focus the reflected light towards the examination area.

In order to improve the light yield of the light emitted by the lighting unit, it is proposed according to the invention that an additional reflector unit be arranged inside the instrument shaft, via which the light emitted by the lighting unit can be fed to the radially expandable area of the instrument shaft. The light emitted distally by the lighting unit can be deflected via this additional reflector unit in such a way that this light component is also fed to the radially expandable area of the instrument shaft and can thus be directed towards the examination area.

Finally, it is proposed with the invention that the lighting unit is designed as at least one LED light or as an optical fiber bundle.

• 1a einen schematischen Längsschnitt durch den Instrumentenschaft einer ersten Ausführungsform eines erfindungsgemäßen Endoskops, den Ausgangszustand darstellend;
• 1b einen Schnitt gemäß 1a, jedoch den Einsatzzustand darstellend;
• 2a einen schematischen Längsschnitt durch den Instrumentenschaft einer zweiten Ausführungsform eines erfindungsgemäßen Endoskops, den Ausgangszustand darstellend;
• 2b einen Schnitt gemäß 2a, jedoch den Einsatzzustand darstellend;
• 2c eine vergrößerte schematische Detailansicht des Details IIc gemäß 2a;
• 3a einen schematischen Längsschnitt durch den Instrumentenschaft einer dritten Ausführungsform eines erfindungsgemäßen Endoskops, den Ausgangszustand darstellend;
• 3b einen Schnitt gemäß 3a, jedoch den Einsatzzustand darstellend;
• 4 einen schematischen Längsschnitt durch den Instrumentenschaft einer vierten Ausführungsform eines erfindungsgemäßen Endoskops, den Einsatzzustand darstellend und
• 5 einen schematischen Längsschnitt durch den Instrumentenschaft einer fünften Ausführungsform eines erfindungsgemäßen Endoskops.

Further features and advantages of the invention emerge from the accompanying drawings, in which various exemplary embodiments of an endoscope according to the invention are shown only by way of example, without restricting the invention to these exemplary embodiments. In the drawings shows:

• 1a a schematic longitudinal section through the instrument shaft of a first embodiment of an endoscope according to the invention, showing the initial state;
• 1b a section according to 1a , but showing the state of use;
• 2a a schematic longitudinal section through the instrument shaft of a second embodiment of an endoscope according to the invention, showing the initial state;
• 2 B a section according to 2a , but showing the state of use;
• 2c an enlarged schematic detailed view of the detail IIc according to FIG 2a ;
• 3a a schematic longitudinal section through the instrument shaft of a third embodiment of an endoscope according to the invention, showing the initial state;
• 3b a section according to 3a , but showing the state of use;
• 4th a schematic longitudinal section through the instrument shaft of a fourth embodiment of an endoscope according to the invention, showing the state of use and
• 5 a schematic longitudinal section through the instrument shaft of a fifth embodiment of an endoscope according to the invention.

The illustrations 1 a to 5 each show schematic longitudinal sections through a hollow instrument shaft 1 a video endoscope, with the instrument shaft 1 at least one image recording unit 2 and at least one lighting unit 3 for illuminating a by means of the at least one image recording unit 2 to be considered are arranged. The one at the distal end 4th of the instrument shaft 1 arranged image pickup unit 2 usually consists of optical lenses 5 as well as an image sensor 6th .

The video endoscopes known from the prior art point in the distal end 4th of the instrument shaft 1 an image recording unit arranged as centrally as possible 2 around which a lighting unit 3 is arranged.

Due to the limited space available within the generally circular cross-section of the instrument shaft 1 With the endoscopes known from the prior art, a compromise must always be made between the size of the image recording unit 2 and the size of the lighting unit 3 can be found in order to obtain a sufficiently good image quality with good illumination of the examination area. The more space for the image pickup unit 2 available, the higher the resolution image sensors 6th with better optics can be used in the instrument shaft 1 to be built in.

The largest possible and thus high-resolution image recording unit 2 in the distal end 4th of the instrument shaft 1 to be able to install, is with the in the pictures 1a to 5 illustrated embodiments the at least one lighting unit 3 in the direction of the longitudinal axis 7th of the instrument shaft 1 viewed on the proximal side in front of the at least one image recording unit 2 in the instrument shaft 1 arranged.

So that the light of the at least one lighting unit 3 with this arrangement of the lighting unit 3 in the instrument shaft 1 is still supplied to the investigation area is in the instrument shaft 1 additionally at least one optical system 8th arranged by the lighting unit 3 directs emitted light in the direction of the study area.

In the case of the 1a to 4th illustrated embodiments of the instrument shaft 1 is an area 9 of the instrument shaft 1 that in the area of the instrument shaft 1 arranged lighting unit 3 is arranged, designed as radially expandable in cross section. The radially expandable area is just for clarity 9 shown in dash-dotted lines. Also this expandable area 9 of the instrument shaft 1 is of course fluid-tight and autoclavable.

About the cross-sectional enlargement of the instrument shaft 1 in this radially expandable area 9 of the instrument shaft 1 is it possible to have a beam of light L. the lighting unit 3 outside of the image acquisition unit 2 over to the study area as shown in the figures 1b , 2 B , 3 and 4th is shown.

In the illustrated embodiments with the radially expandable area 9 of the instrument shaft 1 is the optical system 8th , via which the from the lighting unit 3 emitted light is deflected towards the examination area, as a reflector unit 10 educated.

This is the inside 11 one in the expanded state of the radially expandable region 9 of the instrument shaft 1 sub-area arranged on the proximal side 12 of the radially expandable area 9 the reflector unit 10 forming opaque and reflective and one in the expanded state of the radially expandable area 9 of the instrument shaft 1 Partial area arranged on the distal side 13 of the radially expandable area 9 designed to be translucent.

This training of the reflector unit 10 makes it easy to do with the lighting unit 3 light emitted along the outside of the instrument shaft 1 steer distally towards the investigation area.

At the in 4th The embodiment shown is to reduce the luminous efficiency of the lighting unit 3 to improve the emitted light inside the instrument shaft 1 an additional reflector unit 14th arranged over the that of the lighting unit 3 emitted light the radially expandable area 9 of the instrument shaft 1 is fed. About this additional reflector unit 14th can do that from the lighting unit 3 light emitted distally can be deflected so that this portion of the light also falls within the radially expandable area 9 of the instrument shaft 1 is fed and from there via the reflector unit 10 at the sub-area 12 of the expandable area 9 of the instrument shaft 1 is reflected towards the investigation area.

This additional reflector unit 14th can of course also be used for the ones in the illustrations 1a to 3b illustrated embodiments are used.

To that from the reflector unit 10 The surface of the inside is to focus reflected light towards the study area 11 of the sub-area arranged on the proximal side 12 of the radially expandable area 9 advantageously formed stepped, in particular in the manner of a Fresnel step lens.

While with the ones in the pictures 1a to 3b illustrated embodiments the lighting unit 3 as an LED light 15th is shown, the in 4th Embodiment shown as an optical fiber bundle 16 trained lighting unit 3 on. The type of Training of the lighting unit 3 as an LED light 15th or fiber optic bundles 16 is not essential for the described functionality of the light guide to the investigation area and can be selected as required.

The illustrations 1a to 3b show the instrument shafts 1 in the pictures 1a , 2a and 3a in a non-expanded initial state in which the endoscope is inserted into the examination area and in the images 1b , 2 B and 3b in use with radially expanded area 9 of the instrument shaft 1 .

The transfer of the instrument shaft 1 from the non-expanded initial state to the operational state with a radially expanded area 9 occurs with the in illustrations 1a to 2c illustrated embodiments mechanically, namely by means of articulated rods 17th in the pictures 1a and 1b and by means of a rack and pinion gear 18th in the pictures 2a to 2c .

The mechanics with the articulated rods 17th according to 1a and 1b works similar to opening an umbrella, with the two hinged rods 17th with one in the direction of the longitudinal axis 7th of the instrument shaft 1 axially movable pull / push rod 19th are coupled so that when the push / pull rod is pushed forward 19th the two articulated rods distally 17th to expand the expandable area 9 be pressed radially outwards. To the instrument shaft 1 The pull / push rod is used to return to the non-expanded initial state 19th pulled proximally, causing the articulated rods 17th fold in again and the expandable area 9 collapses.

The rack and pinion gear 18th of the pictures 2a to 2c is constructed so that one about the longitudinal axis 7th of the instrument shaft 1 rotating rod 20th with the distal end 4th of the instrument shaft 1 is coupled, in which the image recording unit 2 is arranged and the distal side of the expandable area 9 of the instrument shaft 1 is located. Proximally behind the expandable area 9 of the instrument shaft 1 points the pole 20th a rack section 21st on that with a toothing 22nd on the inside of the instrument shaft 1 is engaged, as shown in the detailed sketch 2c shows. By turning the rod 20th can be done with the pole 20th coupled distal end 4th of the instrument shaft 1 to form the expandable area 9 of the instrument shaft 1 pull proximally ( 2 B) or to the instrument shaft 1 to return to the unexpanded initial state push it distally ( 2a) .

As the length of the instrument shaft 1 when tightening the distal end 4th of the instrument shaft 1 to form the radially expanded area 9 is shortened, it may be necessary to push the endoscope as a whole in the distal direction in order to achieve the sharpness of the image of the examination area via the image recording unit 2 restore.

The transfer of the instrument shaft 1 from the non-expanded initial state to the operational state with a radially expanded area 9 takes place at the in illustrations 3a and 3b illustrated embodiment pneumatically by generating an overpressure inside the instrument shaft 1 . In the embodiment shown, it is at the proximal end 23 the hermetically sealed instrument shaft 1 a push pin 24 arranged in the interior of the instrument shaft 1 can be pressed. By pressing in the pressure pin 24 the internal pressure in the instrument shaft increases 1 which in turn is the radial expansion of the area 9 of the instrument shaft 1 causes like this in 3b is shown.

As soon as the push pin 24 is pulled out of the inside of the shaft again, the internal pressure in the inside of the shaft drops again and the expandable area 9 of the instrument shaft 1 falls back into the non-expanded initial state according to 3a together.

According to an embodiment not shown, it is also possible that the radial expansion of the instrument shaft 1 thermally through the use of memory metals for the expandable area 9 of the instrument shaft 1 he follows. The expandable area 9 of the instrument shaft 1 is then, for example, always in the expanded state of use without the supply of heat and contracts into the non-expanded initial state with the supply of heat. After switching off the heat supply, the expandable area goes 9 of the instrument shaft 1 then automatically returns to the radially expanded operational state.

In the case of the 1a to 3b illustrated embodiments is the expandable area 9 of the instrument shaft 1 in the radially expanded state of use spherical in longitudinal section.

As an alternative to this embodiment, however, it is also possible to use the expandable area 9 of the instrument shaft 1 in the radially expanded state of use in longitudinal section pyramid-shaped, as shown in 4th is shown.

The illustration 5 shows an alternative embodiment for the formation of the instrument shaft 1 , in which the at least one lighting unit 3 also in the direction of the longitudinal axis 7th of the instrument shaft 1 viewed on the proximal side in front of the at least one image recording unit 2 in the instrument shaft 1 . is arranged, the instrument shaft 1 but no radially expandable area 9 having.

In this embodiment is at the distal end 4th of the instrument shaft 1 around the centrally arranged image recording unit 2 an annular gap 25th between the inner wall of the instrument shaft 1 and the image pickup unit 2 educated. In this annular gap 25th is a lens system 26th arranged that the optical system 8th this embodiment forms in order of the lighting unit 3 radiated light rays L. to be forwarded to the investigation area. The lens system 26th guides the light from the lighting unit 3 on the image acquisition unit 2 over to the study area.

Alternative to the arrangement of the lens system 26th in the annular gap 25th it is of course also possible to use a reflector unit 10 in the annular gap 25th to arrange over which the light of the lighting unit 3 is reflected towards the investigation area.

For the arrangement of the lens system 26th or the reflector unit 10 in the annular gap 25th less space is required than for the arrangement of a powerful lighting unit 3 so that the in 5 embodiment shown more space for a high-resolution image recording unit 2 at the distal end 4th of the instrument shaft 1 remains when the lighting unit is proximally behind the image recording unit 2 in the instrument shaft 1 is arranged.

The ones in the pictures 1a to 5 shown instrument shafts 1 for endoscopes are all characterized by the fact that the relocation of the at least one lighting unit 3 on the proximal side in front of the at least one image recording unit 2 a much larger part of the instrument shaft cross-section for the image acquisition unit 2 used, which means the use of higher resolution image sensors 6th and better optics allowed. To the light of the at least one lighting unit 3 To be able to deliver to the investigation area anyway is part of the instrument shaft 1 at least one optical system 8th arranged by the lighting unit 3 directs emitted light in the direction of the study area.

List of reference symbols

1

Instrument shaft

2

Imaging unit

3

Lighting unit

4th

distal end

5

optical lens

6

Image sensor

7th

Longitudinal axis

8th

optical system

9

expandable area

10

Reflector unit

11

inside

12

Partial area (proximal)

13

Partial area (distal)

14th

Reflector unit

15th

LED light

16

Optical fiber bundle

17th

Articulated rod

18th

Rack and pinion

19th

Pull / push rod

20th

pole

21st

Rack section

22nd

Interlocking

23

proximal end

24

Push pin

25th

Annular gap

26th

Lens system

L.

Beam of light

Claims (12)

Endoscope with a hollow instrument shaft (1), at least one image recording unit (2) and at least one illumination unit (3) for illuminating an examination area to be viewed by means of the at least one image recording unit (2) being arranged in the instrument shaft (1), characterized in that the at least one lighting unit (3) viewed in the direction of the longitudinal axis (7) of the instrument shaft (1) is arranged on the proximal side in front of the at least one image recording unit (2) in the instrument shaft (1) and that in the instrument shaft (1) at least one optical system ( 8) is arranged over which the at least one Lighting unit (3) emitted light can be fed to the examination area. Endoscope after Claim 1 , characterized in that the at least one optical system (8) is designed as a reflector unit (10). Endoscope after Claim 1 , characterized in that the at least one optical system (8) is designed as a lens system (26). Endoscope according to one of the Claims 1 to 3 , characterized in that an area (9) of the instrument shaft (1) in the area of the lighting unit (3) is designed to be radially expandable in cross section. Endoscope after Claim 4 , characterized in that the radial expansion of the instrument shaft (1) takes place mechanically via a rack gear (18) or via articulated rods (17). Endoscope after Claim 4 , characterized in that the radial expansion of the instrument shaft (1) takes place pneumatically by generating an overpressure inside the instrument shaft (1). Endoscope after Claim 4 , characterized in that the radial expansion of the instrument shaft (1) takes place thermally through the use of memory metals for the expandable area (9) of the instrument shaft (1). Endoscope according to one of the Claims 4 to 7th , characterized in that the radially expandable region (9) of the instrument shaft (1) in the expanded state is spherical or pyramid-shaped in longitudinal section. Endoscope according to one of the Claims 4 to 8th , characterized in that the inside (11) of a sub-area (12) of the radially expandable area (9) arranged on the proximal side in the expanded state of the radially expandable area (9) of the instrument shaft (1) is designed to be reflective to form the reflector unit (10) and, that a sub-area (13) of the radially expandable area (9) arranged on the distal side in the expanded state of the radially expandable area (9) of the instrument shaft (1) is designed to be translucent. Endoscope after Claim 9 , characterized in that the upper surface of the inside (11) of the proximally arranged sub-area (13) of the radially expandable area (9) is stepped, in particular in the manner of a Fresnel step lens. Endoscope according to one of the Claims 4 to 10 , characterized in that an additional reflector unit (14) is arranged in the interior of the instrument shaft (1), via which the light emitted by the lighting unit (3) can be fed to the radially expandable area (9) of the instrument shaft (1). Endoscope according to one of the Claims 1 to 11 , characterized in that the lighting unit (3) is designed as at least one LED light (15) or as an optical fiber bundle (16).

Images