JP2010075324A - Endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent stored materials at an end of an insertion part of an endoscope from contacting each other without inhibiting diminishment of a diameter size of the endoscope. <P>SOLUTION: An insertion part 10 of an electronic endoscope 2 includes an end 11 formed of a block 70. The block 70 is combined with a circuit board 43 mounted with a solid imaging element 41. An end of a light guide 34 is fixed to the block 70 through a cap 63 for pinching the circuit board 43. The light guide 34 is covered with a protective tube 62. The protective tube 62 is embedded with a net body 65 of braided metal wires. The protective tube 62 has a flat part 66 whose cross section is crushed to be oval at the end. The light guide 34 is fixed to the block 70 in order to accord the direction of the long axis X of the oval of the flat part 66 with the circumferential direction of the insertion part 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an endoscope in which a built-in object inserted through an insertion portion is covered with a protective tube.

  In recent years, optical endoscopes such as electronic endoscopes have been widely used in the medical field. The electronic endoscope includes a solid-state imaging device at a distal end of an insertion portion having a bendable bending portion, and is connected to an image processing (processor) device or a light source device via a connection cord. In diagnosis using an electronic endoscope, the insertion part is inserted into the body of the subject (inside the body cavity), and the inside of the body cavity is illuminated with illumination light supplied from the light source device, and an image of the affected part is captured with a solid-state imaging device. To do. An imaging signal obtained by the solid-state imaging device is transmitted to the processor device, subjected to various signal processing, and then displayed as an endoscopic image on a monitor or the like.

  Forceps into which various kinds of built-in objects such as a signal cable for connecting a solid-state imaging device and a processor device, a light guide for guiding illumination light from a light source device, and an electric scalpel are inserted inside the insertion portion Channels, air / water channels for flowing air and cleaning liquid are loosely inserted. These built-in objects may come into contact with each other and be damaged when the bending portion is bent. In particular, the signal cable and the light guide are configured by bundling a plurality of fine signal lines and optical fibers, and thus are easily damaged by the pressure during contact. Therefore, it is common practice to cover signal cables and light guides using flexible protective tubes (see, for example, Patent Document 1 and Patent Document 2).

In Patent Document 1, the shape of the tube protecting the light guide is flattened in the thickness direction. With this shape, the tube is easily crushed in the thickness direction, so that the flexibility of the light guide can be improved. In Patent Document 2, an endoscope image guide (light guide) is externally covered with a metal net. This net is formed by braiding metal wires having spring properties, and has a higher strength than conventional protective tubes.
JP 2001-116933 A Japanese Patent Laid-Open No. 5-323210

  All the built-in objects loosely inserted into the insertion portion are fixed to a cylindrical hard block (tip end main body) provided at the tip of the insertion portion. A solid-state image sensor is further assembled in this block. On the other hand, the insertion portion is highly demanded to be reduced in diameter for the purpose of reducing the burden on the subject when inserted into the body cavity. Therefore, the block that affects the outer diameter of the insertion portion is as small as possible. As a result, the built-in objects and the solid-state imaging device are densely packed in a narrow space.

  When the built-in object fixed to the block comes into contact with the solid-state image sensor or the signal cable, the electrical signal flowing through the solid-state image sensor is affected, causing image quality degradation of the endoscope image, malfunction of the solid-state image sensor, and the like. In view of this, consideration has been given to making the built-in objects smaller in diameter so as not to come into contact with the solid-state imaging device, or to devise arrangement of the built-in objects. In particular, the light guide is disposed close to the solid-state imaging device for the purpose of increasing the brightness of the image, and thus the outer diameter of the light guide is particularly limited.

  However, when the light guide is covered with a protective tube, there arises a problem that the protective tube comes into contact with the solid-state imaging device. If the tube is formed flat as in Patent Document 1, the size of the tube is reduced in the flattened direction, so that contact with the solid-state imaging device can be avoided. However, since the insertion portion of the electronic endoscope may be extremely curved, the strength becomes insufficient when the entire tube is flattened. Therefore, if the flat tube is covered with the net of Patent Document 2 in order to improve the strength, this results in the net coming into contact with the solid-state imaging device.

  Furthermore, when the tube is flattened over the entire length, there is a problem that the optical fiber is not fit. In the insertion portion, there is a relatively large space except for the vicinity of the block. Therefore, there is little advantage that the tube is flattened over the entire length from the viewpoint of accommodation of the optical fiber.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an endoscope capable of preventing contact between built-in objects at the distal end of the insertion portion without hindering the diameter reduction of the endoscope. It is to provide.

  In order to achieve the above object, an endoscope according to the present invention includes a built-in object that is inserted through an insertion part that is inserted into a subject and the distal end of which is fixed to a block at the distal end of the insertion part, and the built-in object. A flexible protective tube to be covered, in which a metal reinforcing member is embedded at least in part, and only the end on the block side is a flat part having an elliptical cross section, and the other part is a cylindrical part having a circular cross section. And a tube.

  The flat portion preferably has an outer diameter shorter than that of the cylindrical portion. Moreover, it is preferable that the flat part has lower rigidity than the cylindrical part. In order to lower the rigidity of the flat portion than the cylindrical portion, the embedding density of the metal reinforcing member may be lower in the flat portion than in the cylindrical portion.

  Moreover, it is preferable that the said protection tube is attached so that the long-axis direction of the ellipse of the said flat part may follow the circumferential direction of an insertion part.

  It is preferable that an end portion of the protection tube on the block side is attached and an attachment portion formed in an elliptical cross section is provided. In this case, the flat portion is formed by attaching an end portion of the protection tube on the block side to the attachment portion.

  The built-in object is a light guide that guides illumination light, and the light guide is disposed in the vicinity of a signal cable connected to a circuit board of a solid-state imaging device.

  The metal reinforcing member is a mesh formed by braiding elastic metal wires, or a screw tube obtained by spirally winding an elastic metal string.

  According to the present invention, since the flat portion having an elliptical cross section is provided only at the end of the protection tube on the block side to which the tip of the built-in object is fixed, the end of the protection tube is located near the block where the built-in objects are dense. No contact with other built-in items. Further, since the cylindrical portion other than the flat portion has a circular cross section, the built-in object can be accommodated well. Furthermore, since the protective tube has a metal reinforcing member at least partially, the strength is improved and the built-in object can be reliably protected.

  Since the outer diameter of the flat portion is made shorter than the outer diameter of the cylindrical portion, the flat portion can be reduced in spread, which can contribute to the reduction in the diameter of the insertion portion. Furthermore, since the rigidity of the flat portion is lowered, it can be easily flattened when the flat portion is formed, and workability is improved.

  In FIG. 1, an electronic endoscope 2 is connected to a flexible insertion portion 10 to be inserted into a body cavity of a patient and a distal end portion of the insertion portion 10 as is well known, and a solid-state imaging device 41 (FIG. 3). And the like, a bending portion 12 disposed behind the leading end portion 11 and connecting a plurality of bending pieces, and an operation portion 13 connected to a proximal end portion of the insertion portion 10; A connector (not shown) connected to the processor device and the light source device (both not shown) and a universal cord 14 connecting the operation unit 13 are provided.

  The operation section 13 is provided with an angle knob 15 for bending the bending section 12 in the vertical and horizontal directions, an air supply / water supply button 16 for ejecting air and water from the distal end section 11, and the like. A forceps port 17 through which a treatment tool such as an electric knife is inserted is provided on the insertion unit 10 side of the operation unit 13.

  2 and 3, an observation window 30, an illumination window 31, a forceps outlet 32, and an air / water supply nozzle 33 are provided on the end surface 11 a of the distal end portion 11. The observation window 30 is disposed at the center on one side of the end surface 11a. Two illumination windows 31 are arranged at symmetrical positions with respect to the observation window 30. Behind the illumination window 31, an exit end of a light guide 34 for guiding illumination light from the light source device is disposed. The illumination window 31 irradiates the observation site in the body cavity with the illumination light guided by the light guide 34. As will be described in detail later, the light guide 34 is attached to a through hole 73 (see FIG. 5) formed in the block 70 of the distal end portion 11 through a cylindrical base 63 fixed to the distal end.

  The forceps outlet 32 is connected to a forceps channel 35 disposed in the insertion portion 10 and communicates with the forceps port 17. The distal end of the treatment instrument inserted through the forceps port 17 is exposed from the forceps outlet 32. The air supply / water supply nozzle 33 is supplied from the air supply / water supply device built in the light source device via the air supply / water supply channel 47 (see FIG. 5) in accordance with the operation of the air supply / water supply button 16. And water are sprayed toward the observation window 30.

  In the back of the observation window 30, a lens barrel 37 is disposed that holds an objective optical system 36 for capturing image light of a site to be observed in the body cavity. The lens barrel 37 is attached so that the optical axis of the objective optical system 36 is parallel to the central axis of the distal end portion 11.

  A prism 38 is provided at the rear end of the lens barrel 37. The prism 38 has an incident surface connected to the lens barrel 37 and an output surface connected to the cover glass 39. A solid-state image sensor 41 is attached to the lower part of the cover glass 39 via a square frame spacer 40. Thereby, the optical axis of the objective optical system 36 and the surface of the light receiving unit 42 of the solid-state imaging device 41 are parallel.

  The solid-state image sensor 41 is composed of a CCD image sensor or a CMOS image sensor, for example. The solid-state imaging device 41 uses a bare chip in which a light receiving portion 42 is provided on the surface and an electrode pad is provided on the rear end portion. The solid-state image sensor 41, the spacer 40, and the cover glass 39 are assembled by being bonded together with an adhesive. The light receiving unit 42 is accommodated in a sealed space surrounded by the spacer 40 and the cover glass 39, and the light receiving unit 42 is protected from intrusion of dust, water, and the like.

  A circuit board 43 is attached to the rear end of the solid-state imaging device 41. The circuit board 43 has an electrode pad at its front end, and the electrode pad and the electrode pad of the solid-state imaging device 41 are electrically connected by a bonding wire or the like. The circuit board 43 includes, for example, a circuit for transmitting a drive signal for driving the solid-state image sensor 41, a circuit for performing signal processing such as digitizing the image signal from the solid-state image sensor 41, and a processor for processing the image signal. A circuit or the like for transferring to the device is mounted.

  A plurality of electrode pads 44 are provided at the rear end of the circuit board 43, and signal lines 46 drawn from the signal cable 45 are soldered to the electrode pads 44. The signal cable 45 mediates exchange of signals between the circuit board 43 and the processor device. Note that the signal cable 45 is a multi-core cable composed of a plurality of signal lines 46, but only one signal line 46 is shown in the figure to avoid complication.

  In FIG. 4, a light guide 34 covers a bundle 60 of a plurality of quartz optical fibers 60a, a restraint tube 61 into which the optical fiber bundle 60 is inserted and loosely restrains and holds the optical fiber bundle 60, and covers these. It is comprised with the protection tube 62 to protect. The restraint tube 61 is made of a flexible thin film such as silicon resin. In order to prevent the optical fiber 60a from coming off, the restraint tube 61 is fixed to the optical fiber bundle 60 by, for example, a thread winding, and the optical fiber bundle 60 is bundled into a cylindrical shape having a diameter of about 1.7 mm. The distal end portion of the restraining tube 61 is fitted into the base 63 together with the optical fiber bundle 60. In the following description, the optical fiber bundle 60 held by the restraining tube 61 is referred to as a fiber bundle 64.

  The base 63 has an inner diameter that is slightly smaller than the outer diameter of the fiber bundle 64. The base 63 is caulked from the outside, whereby the tip of the fiber bundle 64 is fixed to the base 63.

  The protective tube 62 is made of a resin having flexibility, and has a length from the rear end portion of the base 63 to the rear end portion of the curved portion 12. A net body 65 is embedded in the protective tube 62. The net body 65 is formed by braiding thin metal wires having spring properties, such as stainless steel and tungsten, with a predetermined number and number of strikes. The protective tube 62 is held in a cylindrical shape by the net body 65.

  The protective tube 62 includes a flat portion 66, a tapered portion 67, and a cylindrical portion 68. The flat portion 66 is fixed to the outer periphery of the rear end portion of the base 63 with an adhesive. The flat portion 66 has an elliptical cross section and covers from the rear end of the base 63 to a part of the fiber bundle 64. The flat portion 66 has a short axis Y (see FIG. 6) of an inner diameter of about 1.6 mm, and sandwiches the fiber bundle 64 between the inner surfaces in the direction of the short axis Y. In this example, a portion of the protective tube 62 located within a range of about 15 mm from the rear end of the block 70 is a flat portion 66.

  The cylindrical portion 68 is connected to the flat portion 66 through the tapered portion 67, has a substantially circular cross-sectional shape, and has an inner diameter of about 2.0 mm. Since this inner diameter is larger than the outer diameter of the fiber bundle 64, the cylindrical portion 68 gently covers the fiber bundle 64 with a gap. Since the fiber bundle 64 can be freely displaced in the gap with the cylindrical portion 68, the light guide 34 has a good bendability. Further, since the cylindrical portion 68 has a substantially circular cross section, the fiber bundle 64 can be accommodated well.

  The flat portion 66 has a smaller outer diameter than the cylindrical portion 68. The tapered portion 67 is a portion provided to absorb the difference in outer diameter between the flat portion 66 and the cylindrical portion 68, and the outer diameter gradually decreases from the cylindrical portion 68 toward the flat portion 66.

  The protective tube 62 is manufactured, for example, by pouring molten resin into a mold holding the mesh body 65, integrally molding them, and heat-shrinking the tip portion corresponding to the flat portion 66 into an elliptical cross section. . Of course, other manufacturing methods may be used.

  As shown in FIG. 5, the light guide 34 is fixed to a metal cylindrical block 70 at the distal end portion 11 together with the forceps channel 35, the signal cable 45, and the air / water supply channel 47. The block 70 is also assembled with a forceps pipe 71 into which the tip of the forceps channel 35 is fitted and an air / water feed pipe 72 into which the tip of the air / water feed channel 47 is fitted.

  The block 70 is formed with a pair of through holes 73 so as to sandwich the circuit board 43. A base 63 of the light guide 34 is inserted into the through hole 73. The base 63 is screwed after being inserted into the through hole 73, and is fixed to the block 70 by closing the through hole 73 with an adhesive or the like. At this time, as schematically shown in FIG. 6A, the light guide 34 is attached so that the direction of the long axis X of the flat portion 66 and the circumferential direction of the block 70 and thus the insertion portion 10 coincide.

  The operation of the electronic endoscope 2 configured as described above will be described. When observing the inside of a patient's body cavity with the electronic endoscope 2, the operator connects the electronic endoscope 2, the processor device, and the light source device, and inserts the insertion portion 10 into the body cavity. Then, by appropriately operating the operation unit 13 to perform a procedure such as bending the bending unit 12 and directing the distal end portion 11 in a desired direction, while illuminating the inside of the body cavity with illumination light from the light source device, An endoscopic image in the body cavity by the image sensor 41 is observed on a monitor.

  When the insertion portion 10 is inserted into the body cavity or when the bending portion 12 is bent, built-in objects such as the light guide 34, the forceps channel 35, and the signal cable 45 come into contact with each other and are pressed against each other. The pressing force applied to the light guide 34 is relaxed and absorbed by the spring property of the net body 65 and does not reach the inner optical fiber bundle 60. Further, since the rigidity in the bending direction is increased by the net body 65, the degree of bending of the light guide 34 is averaged. Therefore, it is possible to effectively prevent the optical fiber 60a from buckling and breaking.

  In the block 70, the light guide 34, the circuit board 43, and the signal cable 45 are concentrated in a narrow space. At this time, if a conventional protective tube without the flat portion 66 is used, as shown in FIG. 6 (b), the protective tube 62 also contacts the circuit board 43 and, in some cases, the signal cable 45, so that the solid-state imaging device. 41 electrical signals are affected. As a result, problems such as deterioration of the image quality of the endoscopic image and malfunction of the solid-state imaging device 41 occur.

  On the other hand, when the protective tube 62 of the present invention is used, the direction of the short axis Y of the flat portion 66 substantially coincides with the radial direction of the block 70, and the diameter of the protective tube 62 decreases in the radial direction of the block 70. Therefore, contact with the circuit board 43 and the signal cable 45 can be avoided, and problems such as deterioration of the image quality of the endoscope image and malfunction of the solid-state imaging device 41 do not occur. In FIG. 6, the forceps channel 35, the air / water supply channel 47, etc. are not shown for simplification.

  In general, when the cross section is flattened, the strength in the direction of the minor axis Y decreases, but the flat portion 66 is only the tip portion fixed to the block 70, and therefore the overall strength of the protective tube 62 does not decrease.

  In the above embodiment, the length of the flat portion 66 is about 15 mm from the rear end of the block 70, but the flat portion 66 may be of a length that can avoid contact with the circuit board 43. It can be determined appropriately according to the amount of protrusion of the circuit board 43.

  The flat portion 66 can be easily formed by simply crushing the tip of the cylindrical portion 68 using thermal deformation or the like. However, when the flat portion 66 is formed in this way, the long axis is longer than that of the cylindrical portion 68. The outer diameter greatly expands in the X direction. Therefore, as in the above embodiment, the outer diameter of the flat portion 66 is formed shorter than the outer diameter of the cylindrical portion 68, and these are connected by the tapered portion 67. In this way, the spread of the outer diameter in the direction of the major axis X of the flat part 66 is reduced, and the area occupied by the flat part 66 in the vicinity of the block 70 is smaller than in the case where a protective tube having a cylindrical body 68 only is used. Get smaller. Therefore, the diameter of the distal end portion 11 and the insertion portion 10 can be further reduced.

  In the above embodiment, the net body 65 is provided over the entire length of the protective tube 62, but the net body 65 may be provided only in the cylindrical portion 68 as in the protective tube 75 shown in FIG. Alternatively, the embedding density of the metal wires constituting the net body 65 may be lower than that of the cylindrical portion 68 in the flat portion 66 and the tapered portion 67 as in the protective tube 80 shown in FIG. According to this structure, since the rigidity of the flat part 66 becomes low, it can be made flat easily at the time of formation of the flat part 66, and it becomes easy to maintain the shape of the flat part 66. Further, workability when the flat portion 66 is fixed to the base 63 is improved.

  In the said embodiment, although the net | network body 65 was illustrated as a metal reinforcement member, a metal reinforcement member is not restricted to this. As in the protective tube 85 shown in FIG. 8, a screw tube 86 may be used instead of the net body 65. The screw tube 86 is formed by spirally winding an elastic metal string similarly to the net body 65. The cross-sectional shape of the screw tube 86 may be the illustrated rectangular shape or a circular shape. The same effect as that of the net body 65 can be obtained.

  In the above embodiment, the protective tube 62 in which the flat portion 66 is formed in advance is used. For this reason, the operation | work which attaches the flat part 66 to the nozzle | cap | die 63 is easy, and the dispersion | variation in the shape of the flat part 66, such as the dimension of the long axis X and the short axis Y, the length of flat part 66 itself, can be suppressed. On the other hand, considering the processing cost of the flat portion 66, there is a disadvantage that the unit price of the protective tube 62 is high.

  Therefore, although the advantage of being able to suppress the mounting work and the variation in shape is somewhat lost, a protective tube 90 (see FIG. 9) having a short cylinder may be used. In this case, when the protective tube 90 is fixed to the base 63, the application location of the adhesive is appropriately selected so that the tip thereof has an elliptical cross section. Since the protective tube 90 having a small cylinder is inexpensive because the flat portion 66 is not formed in advance, the cost of parts can be reduced.

  In addition, in order to improve workability | operativity etc. at the time of using the protective tube 90 of a short cylinder, you may employ | adopt the block 95 shown in FIG. An elliptical attachment portion 96 is formed near the through hole 73 of the block 95. The attachment portion 96 protrudes from the rear end surface of the block 95 by the length of the flat portion to be formed. The direction of the long axis X ′ of the attachment portion 96 coincides with the circumferential direction of the block 95 and thus the insertion portion 10. A flat tube portion similar to that of the above-described embodiment is formed by fitting the protective tube 90 having a small cylinder into the attachment portion 96 and bonding the same. According to this configuration, since the entire surface of the protection tube 90 and the attachment portion 96 are bonded to each other as compared with the above-described embodiment in which only the inner surface of the flat portion 66 in the direction of the short axis Y is fixed to the base 63, the protection tube is fixed. Can be made more rigid.

  In addition, you may provide an attaching part in a nozzle | cap | die instead of a block. In addition, when the protective tube 90 having a small cylinder is used, the outer diameter of the portion that becomes the flat portion may be made smaller than the outer diameter of the cylindrical portion, or the rigidity may be lowered as in the above embodiment.

  In the above embodiment, the protective tube is applied to the light guide, but the signal cable may be covered with the protective tube. Of course, other built-in objects may be covered with a protective tube. Moreover, although the protective tube is covered only in the curved portion, the entire insertion portion may be covered. Furthermore, in the above-described embodiment, an electronic endoscope is exemplified as an endoscope. However, an ultrasonic endoscope may be used, and not only a medical endoscope but also an industrial endoscope.

It is an external view which shows the structure of an electronic endoscope. It is a top view which shows the end surface of the front-end | tip part of an electronic endoscope. It is sectional drawing which shows the structure of the front-end | tip part of an electronic endoscope. It is sectional drawing which shows the structure of a light guide. It is a perspective view which shows the block vicinity of the front-end | tip part of an electronic endoscope. It is explanatory drawing which shows typically the positional relationship of a light guide and a circuit board, (a) shows the case where a flat part is provided, (b) shows the case where a flat part is not provided. It is a top view which shows another embodiment of a protection tube. It is sectional drawing of the protection tube which employ | adopted the screw tube as a metal reinforcement member. It is an expansion perspective view which shows the example which provided the attachment part of the protection tube in the block.

Explanation of symbols

2 Electronic endoscope 10 Insertion part 11 Tip part 34 Light guide 41 Solid-state image sensor 43 Circuit board 45 Signal cable 60 Optical fiber bundle 62, 75, 80, 85, 90 Protection tube 65 Net body 66 Flat part 68 Cylindrical part 70, 95 Block 86 Screw tube 96 Mounting part

Claims (8)

A built-in object that is inserted into an insertion part that is inserted into a subject and whose tip is fixed to a block at the tip of the insertion part;
It is a flexible protective tube that covers the built-in object, a metal reinforcing member is embedded at least in part, and only the end on the block side is a flat part with an elliptical cross section, and the other part is a circular cylinder with a circular cross section A protective tube,
An endoscope characterized by comprising:   The endoscope according to claim 1, wherein the flat portion has an outer diameter shorter than that of the cylindrical portion.   The endoscope according to claim 1, wherein the flat portion has lower rigidity than the cylindrical portion.   The endoscope according to claim 3, wherein the flat portion has an embedded density of the metal reinforcing member lower than that of the cylindrical portion.   The endoscope according to any one of claims 1 to 4, wherein the protective tube is attached so that a major axis direction of an ellipse of the flat portion is along a circumferential direction of the insertion portion. The end of the protection tube on the block side is attached, and includes an attachment portion formed in an elliptical cross section.
The endoscope according to any one of claims 1 to 5, wherein the flat portion is formed by attaching an end portion of the protection tube on the block side to the attachment portion. The built-in object is a light guide for guiding illumination light,
The endoscope according to any one of claims 1 to 6, wherein the light guide is arranged in the vicinity of a signal cable connected to a circuit board of a solid-state imaging device.   8. The metal reinforcing member according to claim 1, wherein the metal reinforcing member is a net formed by braiding elastic metal wires, or a screw tube formed by spirally winding a metal string having elasticity. The endoscope described.

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