1. Field of the Invention
The present invention relates to an endoscope in which a hard distal end portion incorporated in an insertion portion and a bending portion are consecutively arranged.
2. Description of the Prior Art
In recent years, endoscope systems have been commonly utilized that make it possible to insert an insertion portion into a body cavity or a pipe and implement observation, while displaying a subject image on a screen of a display apparatus. In general, endoscopes utilized in the foregoing endoscope systems include a distal end portion and a bending portion in the distal end of an elongated insertion portion. By providing the bending portion in the insertion portion of the endoscope and bending the bending portion, the distal end portion is oriented to a desired direction.
The distal end portion of the endoscope is formed of a hard material. In the distal end portion, an illumination optical system for illuminating an examination site and an image-capturing optical system for obtaining the observation image of the examination site illuminated by the illumination optical system are arranged. In addition, in an endoscope for the purpose of implementing not only observation but also treatment, a treatment-device channel for introducing a treatment device into the body cavity is provided, in addition to the illumination optical system and the observation optical system.
From the distal end portion of the endoscope, a bundle of light-guide fibers incorporated in the illumination optical system, part of an image-capturing unit incorporated in the observation optical system, and a signal cable that extends from the image-capturing unit, and, as may be necessary, a channel port metal incorporated in the treatment-device channel, a channel tube one end of which is fixed to the channel port metal, and the like extend outward.
The bending portion of the endoscope is configured of a plurality of bending-portion joint pieces, which are arranged pivotably and consecutively with one another, in such a way as to be able to freely bend up and down or up and down/right and left. By integrally fixing to the proximal portion of the distal end portion a distal-end bending-portion joint piece incorporated in the foremost end of the bending portion, the bending portion and the distal end portion are consecutively arranged.
An endoscope having an insertion portion configured in such a way that, as described above, the bending portion and the distal end portion are consecutively arranged employs a configuration in which the distal-end bending-portion joint piece arranged at the proximal side of the distal end portion and the distal end portion are arranged approximately coaxially with each other. Accordingly, if the bending portion is viewed from the distal endface of the distal end portion, an outline variation portion is seen in which the circumference of the bending portion is approximately evenly larger than that of the distal end portion. Although the dimensions of outer diameters in the bending portion and the distal end portion are different in the center and the diameter dimension of the circumscribing circle of the constituent element, the reason is represented by making the circumscribing circles so as to satisfy the both.
The present invention provides an endoscope in which a hard distal end portion and a bending portion are arranged consecutively with each other at the distal side of the insertion portion. When the center axes of the distal end portion and the bending portion are coupled, the center axes of the distal end portion and the bending portion are eccentric with each other.
An embodiment of the present invention will be explained below, with reference to the drawings.
As illustrated in
The endoscope 2 incorporates an image-capturing unit, described later, having an image-capturing element (not shown), for example, for obtaining observation images of an examination site. The light source device 3 supplies the endoscope 2 with illumination light. The video processor 4 implements the control of the endoscope 2, the signal processing of image signals obtained through the endoscope 2, and the like. The display monitor 5 displays observation images, based on video signals outputted from the video processor 4. The VTR deck 6 and the video disk 7 record observation images. The video printer 8 prints out observation images.
The endoscope 2 is configured mainly of an elongated insertion portion 9, a operation unit 10 situated in the proximal portion of the insertion portion 9, and a universal cord 11 extending from a side of the operation unit 10. The insertion portion 9 is formed, by consecutively arranging a distal end portion 9a, a bending portion 9b, and a flexible tube portion 9c in that order from the distal end of the insertion portion 9.
The distal end portion 9a is formed of a hard material; for example, an illumination optical system and an observation optical system, described later, are arranged therein. The bending portion 9b is configured of a plurality of bending-portion joint pieces arranged consecutively in such a way as to be able to bend, e.g., up and down. The flexible tube portion 11 has flexibility.
In the operation unit 10, for example, an unillustrated bending knob for making the bending portion 9b bend, an air/liquid feed button 10a for controlling an air/liquid feed function, a suction button 10b for controlling a suction function, a switch 10c for remotely implementing a video recording function of the video processor 4 and light-amount adjustment for the light source device 3, and the like are provided. In addition, a treatment-device insertion port 10d is provided through which a treatment device such as a piece of hand-held forceps is introduced into the body cavity.
A light guide for transmitting illumination light, a signal line for transmitting electric signals, and the like are inserted through the universal cord 11. At one end of the universal cord 11, a light-source connector 11 a is provided. The light-source connector 11 a and the light source device 3 are detachably and attachably connected with each other. A connector 12a provided at one end of a signal cable 12 is detachably and attachably connected to the side portion of the light-source connector 11a. A connector 12b provided at the other end of the signal cable 12 is detachably and attachably connected to the video processor 4.
Inside the light source device 3, a lamp 3a is provided. Illumination light from the lamp 3a passes through a condenser lens 3b and then is converged onto the endface of a light-guide port metal 13 protruding from the light-source connector 11a. The illumination light converged onto the endface of the light-guide port metal 13 is introduced to the distal end portion 9a of the insertion portion 9, by way of the universal cord 11 and a bundle of light-guide fibers that is inserted through the endoscope 2, and irradiated from the illumination optical system onto an examination site.
The optical image of the examination site onto which the illumination light is irradiated passes through an objective lens provided in the distal end portion 9a and formed on an image-capturing element provided in the image-capturing unit. The image-capturing element converts the formed optical image into an electric signal and transmits the electric signal to the video processor 4, by way of the signal line. The video processor 4 converts the transmitted electric signal into a video signal and outputs the video signal to the display monitor 5. Accordingly, an endoscopic image captured by the image-capturing element is displayed on the display monitor 5.
As illustrated in
As illustrated in
As illustrated in FIGS. 2 to 4 and 6, in consideration of observation performance and cleaning performance, the distal endface 20a of the distal-end constituent member 20 is formed, in a stepped contour, provided with a first plane 25 and a second plane 26 that are different from each other in level. Slopes 27, in each of
As illustrated in
Reference numeral 37 denotes a signal cable that extends from the image-capturing unit 32. Various kinds of signal wires 38 are inserted through the signal cable 37. Reference numeral 39 denotes a sealing resin that seals the image-capturing element, the circuit board, the signal wires 38, and the like.
In the proximal portion of the illumination lens 22, a rod lens 41 and the bundle of light-guide fibers 42 are disposed. The illumination lens 22 is fixed to the illumination-optical-system through-hole 20c, by means of an adhesive. Adhesion puddle 43 is provided at a predetermined position in the illumination-optical-system through-hole 20c to which the illumination lens 22 is fixed. By providing the adhesion puddle 43 in the illumination-optical-system through-hole 20c, it is possible to prevent the adhesive from flowing on the surface, of the curved portion, to which surface treatment is applied, when the illumination lens 22 is adhered to the through-hole 20c.
The air/water feed nozzle 24 is formed approximately in an L shape. An air/water feed through-hole 45 is formed in the proximal portion of the air/water feed nozzle 24. A water feed port metal 46 is disposed in the air/water feed through-hole 45; one end of a water feed tube 47 is coupled with the water feed port metal 46.
In addition, in the proximal portion of the treatment-device opening 23, a treatment-device-channel port metal (refer to reference numeral 48, in
As illustrated in
The bending-portion joint pieces 51 are coupled with one another, by means of connecting pins 54, pivotably and consecutively. The net tube 52 is formed, e.g., by knitting wires made of a polymeric material or metal, in a circular-tube fashion. The coating tube 53 is a rubber material, or an elastomer such as a urethane resin, that has high extensibility.
A distal-end bending-portion joint piece 51 a situated at the foremost end of the bending portion 9b is fixed being coupled with a distal-end bending-portion joint piece arrangement stage (refer to reference numeral 71, in
A pair of bending operation wires (briefly referred to as a wire, hereinafter) 55 is integrally fixed, through soldering or the like, to a pair of predetermined positions on the inner surface of the distal-end bending-portion joint piece 51a. With regard to the arrangement position of the wire 55, the gravity-center position is taken into account so that, in implementing bending manipulation of the bending portion 9b, the bending-force amount becomes as light as possible. In the present embodiment, the wires 55 are situated above and below, in the drawing, the treatment-device channel tube 49. Accordingly, when, under the conditions that the treatment device is being inserted and not being inserted yet through the treatment-device channel tube 49, an operator manipulates the unillustrated bending knob, the bending portion is smoothly bent.
As illustrated in
The nozzle portion 61 is formed so as to protrude by a predetermined distance from the flat portion 63a. In addition, in the nozzle portion 61, an abutting surface 65 is provided that abuts on the second plane 26 of the distal-end constituent member 20. Moreover, in the nozzle portion 61, the groove portion 66 is formed that is formed by cutting off the middle part of the abutting surface 65 incorporated in the emission outlet.
As illustrated in
In addition, the depth, of the groove portion 66, from the abutting surface 65 is set in such a way that, under the condition that, as described above, the air/water feed nozzle 24 is disposed in the nozzle-arrangement hole 20e and the abutting surface 65 abuts on the second plane 26, the groove-portion bottom side 66a is situated shifted by a predetermined dimension t from the surface of the objective lens 21 toward the distal end.
Accordingly, by, with the air/water feed nozzle 24 disposed in the distal-end constituent member 20, situating the groove-portion bottom side 66a incorporated in the emission outlet always shifted by the predetermined distance t from the surface of the objective lens 21 toward the distal end, provision is made for a fluid emitted from the emission outlet to evenly cover the surface of the objective lens 21.
As illustrated in
Accordingly, by disposing the nozzle fixation portion 62 of the air/water feed nozzle 24 in the nozzle-arrangement hole 20e, the emission outlet provided in the air/water feed nozzle 24 faces the objective lens 21 and is prevented from rotating.
After the air/water feed nozzle 24 is disposed in the nozzle-arrangement hole 20e, the air/water feed nozzle 24 is integrally fixed to the distal-end constituent member 20, by means of a fixation screw 69 as a fixation member, as illustrated in
Next, the configuration of the distal-end constituent member 20 will be explained with reference to
The distal-end constituent member 20 illustrated in
As illustrated in
That is to say, in the distal-end constituent member 20, the center position OA for defining the contour of the distal-end formation portion 74 and the center position OB for defining the peripheral face of the distal-end bending-portion joint piece arrangement stage 71 on which the distal-end bending-portion joint piece 51a is arranged are made eccentric with each other (also described “offset from each other”). Accordingly, when the distal-end bending-portion joint piece 51a is arranged on the distal-end bending-portion joint piece arrangement stage 71 of the distal-end constituent member 20 to configure the insertion portion 9, as shown in
The spacing between the inner surface of the distal-end bending-portion joint piece 51a and the image-capturing unit 32 and the spacing between the inner surface of the distal-end bending-portion joint piece 51a and the treatment-device channel tube will be compared between the case where, with the configuration in which the center positions OA and OB are offset with each other, the distal-end bending-portion joint piece 51a is arranged on the distal-end bending-portion joint piece arrangement stage 71 and the case where, with the configuration in which the center positions OA and OB are coaxial with each other, the distal-end bending-portion joint piece 51a is arranged on the distal-end bending-portion joint piece arrangement stage 71. The comparison results in the fact that the positional relationship in the case of the offset configuration is imbalanced toward one side, compared to the positional relationship in the case of the coaxial configuration.
In the present embodiment, the endoscope is configured in such a way that the image-capturing unit is arranged within a region that is different from the offset-side region in which the middle-side, of the bending portion, that is made offset with respect to the center axis of the distal end portion is situated. Accordingly, an imbalance is produced in which the spacing between the inner surface of the distal-end bending-portion joint piece 51a and the image-capturing unit 32 is narrowed and the spacing between the inner surface of the distal-end bending-portion joint piece 51a and the treatment-device channel tube is widened. Thus, in the configuration in which the center positions OA and OB are offset from each other, the distal-end bending-portion joint piece 51a is formed in such a way that the diameter thereof is small, in order to solve the imbalance. Accordingly, the spacing between the inner surface of the distal-end bending-portion joint piece 51a and the treatment-device channel tube is narrowed, without changing the spacing between the inner surface of the distal-end bending-portion joint piece 51a and the image-capturing unit 32, whereby the state is solved in which the distal-end bending-portion joint piece 51a is offset with respect to the distal-end formation portion 74.
In addition, in order to reduce the diameter of the bending portion 9b, in the distal-end bending-portion joint piece arrangement stage 71, notched portions 75b, 75c, 75d, and 75e are formed that are for removing the peripheral walls, i.e., the so-called side walls of the observation-optical-system through-hole 20b, the illumination-optical-system through-hole 20c, the treatment-device channel through-hole 20d, and the nozzle-arrangement hole 20e. By removing the peripheral walls to form the notched portions 75b, 75c, 75d, and 75e, the eccentricity, of the center position OB, with respect to the center position OA is made enlarged, whereby the diameter of the distal-end bending-portion joint piece 51a can further be reduced.
Specifically, as illustrated in
Provided the notched portion 75b is not formed, it is required to enlarge the inner diameter of the distal-end bending-portion joint piece 51a, by a dimension corresponding to the wall thickness of the peripheral wall, of the distal-end bending-portion joint piece arrangement stage 71, that is not cut off. In other words, that inner diameter is rendered larger than that of the distal-end bending-portion joint piece 51a illustrated in
In addition, by forming the notched portions 75b, 75c, 75d, and 75e, a first protrusion portion 71a and a second protrusion portion 71b are provided, as illustrated in
As described above, in forming the distal-end bending-portion joint piece arrangement stage in the distal-end constituent member, the center position OA for defining the contour of the distal-end formation portion corresponding to the contour of the distal-end constituent member and the center position OB for defining the peripheral face of the distal-end bending-portion joint piece arrangement stage on which the distal-end bending-portion joint piece is arranged are made eccentric with each other. By making the distal-end bending-portion joint piece small-diameter to eliminate the state that the distal-end bending-portion joint piece arranged on the distal-end bending-portion joint piece arrangement stage and the distal-end formation portion are offset from each other, the diameter of the bending portion including the distal-end bending-portion joint piece and joint pieces that are consecutively connected with the distal-end bending-portion joint piece can be reduced.
As a result, the fact is eliminated that, in the case where the distal end portion and the bending portion are consecutively arranged in such a way that the center axis of the bending portion offset from the center axis of the distal end portion, the outline of the bending portion evenly becomes larger than the peripheral face of the distal end portion. In other words, outline variation portions are eliminated that are evenly formed around the overall circumference of the insertion portion. Accordingly, by appropriately implementing twisting manipulation and bending manipulation, the operator can more smoothly insert the insertion portion into body cavities.
Moreover, by cutting out the peripheral walls, of the distal-end bending-portion joint piece arrangement stage, that are the outer circumference portions of the through-holes into which inner devices are inserted, and thereby making the distal-end bending-portion joint piece closer to the inner devices, the eccentricity of the center position OB with respect to the center position OA is made further larger and the diameter of the distal-end bending-portion joint piece is further reduced, whereby the diameter of the bending portion can be reduced. Accordingly, the insertion portion can more smoothly be inserted into body cavities.
In addition, it is to be understood that the present invention is not limited to the foregoing embodiment, and modifications to the foregoing embodiments may be implemented without departing from the spirit and scope of the present invention.
Number | Date | Country | Kind |
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2004-045189 | Feb 2004 | JP | national |
This application is a continuation application of PCT/JP2005/002634 filed on Feb. 18, 2005 and claims benefit of Japanese Application No. 2004-045189 filed in Japan on Feb. 20, 2004, the entire contents of which are incorporated herein by this reference.
Number | Date | Country | |
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Parent | PCT/JP05/02634 | Feb 2005 | US |
Child | 11506138 | Aug 2006 | US |