JP5548575B2 - Endoscope - Google Patents

Description

  The present invention relates to an endoscope.

  As an endoscope used for diagnosis of particularly thin parts such as the bile duct and pancreatic duct in the vicinity of the duodenum, an objective lens of the imaging system and an opening of the treatment instrument tube are provided on the side surface of the distal end portion of the endoscope insertion portion. Side-viewing endoscopes are used. For example, when diagnosing the inside of the bile duct that opens to the duodenum, a catheter is inserted into the treatment instrument tube, a contrast medium is injected into the bile duct by the catheter, and fluoroscopy is performed. Alternatively, a child endoscope (fiber scope) is inserted into the bile duct through the treatment instrument tube and observation is performed (Patent Document 1). In this case, since the inside of the treatment instrument tube is occupied by the child endoscope, forceps and the like cannot be inserted into the treatment instrument tube and used. In other words, in a narrow area such as the inside of the bile duct, only observation was possible and treatment was not possible.

  Here, in order to enable observation and treatment at the same time, a direct-view endoscope in which an objective lens is provided forward in the insertion direction at the distal end of the insertion portion is used, and the insertion portion of the endoscope is directly placed inside the bile duct. Although it can be considered to be inserted, in order to use it in a narrow space such as the duodenum, the bending performance of the insertion portion is important. Regarding the improvement of the bending performance, each of the first four-way bending piece and the second four-way bending piece combined for turning in the four directions of up, down, left and right, and the two-way piece rotating in the two directions up and down. There is an example in which the distance between pins is set to an appropriate value (Patent Document 2). According to this example, the curvature radius of the curved portion can be curved with a smooth shape without locally changing.

JP 2003-144381 A JP 2002-209832 A

As described above, an attempt has been made to improve the operability of the endoscope by smoothly bending the bending portion when the bending operation is performed, but in recent years, an endoscope having a small-diameter insertion portion is used. At the same time, there is a demand to bend the curved portion with a small turn. In particular, in order to insert an insertion part into a bile duct or the like using a small-diameter and direct-view type endoscope and perform observation and treatment at the same time, the curvature radius of the curved part is reduced so that the insertion into the bile duct or the like is easy. Is a problem.
An object of the present invention is to provide an endoscope having a bending performance that is easy to use even in a narrow space in a body cavity.

An endoscope comprising a bending portion that is inserted into a body cavity from the distal end side and bent by a bending operation,
The bending portion has a plurality of node rings that are rotatably connected to each other,
The plurality of node rings are provided with a pivot shaft extending along a first direction intersecting a longitudinal direction in which the curved portion extends, at one end in the longitudinal direction, and in both the longitudinal direction and the first direction. A rotation shaft extending along the intersecting second direction has a first node ring provided at the other end in the longitudinal direction, and a rotation shaft extending in parallel with each other along the first direction at each end in the longitudinal direction. And a second joint ring provided,
The number of the second knuckle ring disposed on the distal end side of the curved portion, rather multi than the number of the disposed proximally of the curved portion second knuckle wheel,
All of the rotation shafts of the second joint ring arranged on the distal end side pass through a position eccentric to the same side from the center of the cross section of the curved portion orthogonal to the longitudinal direction,
An objective lens having an optical axis along the longitudinal direction in a state where the bending portion is not bent is provided at the distal end portion of the endoscope,
An endoscope in which an optical axis of the objective lens is set on a plane including rotation axes of a plurality of second joint rings arranged on the distal end side in a state where the bending portion is not bent .

An endoscope comprising a bending portion that is inserted into a body cavity from the distal end side and bent by a bending operation,
The bending portion has a plurality of node rings that are rotatably connected to each other,
The plurality of node rings are provided with a pivot shaft extending along a first direction intersecting a longitudinal direction in which the curved portion extends, at one end in the longitudinal direction, and in both the longitudinal direction and the first direction. A rotation shaft extending along the intersecting second direction has a first node ring provided at the other end in the longitudinal direction, and a rotation shaft extending in parallel with each other along the first direction at each end in the longitudinal direction. And a second joint ring provided,
The number of rotating shafts extending along the first direction disposed on the distal end side of the bending portion is greater than the number of rotating shafts extending along the first direction disposed on the proximal end side of the bending portion. also rather large,
All of the rotation shafts of the second joint ring arranged on the distal end side pass through a position eccentric to the same side from the center of the cross section of the curved portion orthogonal to the longitudinal direction,
An objective lens having an optical axis along the longitudinal direction in a state where the bending portion is not bent is provided at the distal end portion of the endoscope,
An endoscope in which an optical axis of the objective lens is set on a plane including rotation axes of a plurality of second joint rings arranged on the distal end side in a state where the bending portion is not bent .

  According to the endoscope of the present invention, since the radius of curvature of the bending portion is small, bending performance that is easy to use can be obtained even in a narrow space in the body cavity.

1 is an external view of an endoscope that is an example for describing an embodiment of the present invention. FIG. It is a front view of the front-end | tip part of an insertion part. It is a side view of the curved part of the state which removed the outer skin member. It is a perspective view of a 1st joint ring and a 2nd joint ring. It is sectional drawing of the curved part in a base end side area | region. It is sectional drawing of the curved part in a front end side area | region. It is a figure which shows the bending state to the up-down direction of a bending part. It is a figure which shows the bending state to the left-right direction of a bending part. It is the schematic of the duodenum vicinity, and the figure which notched a part of duodenum. It is a figure which shows the state by which the front-end | tip part was inserted in the bile duct. It is a side view of the curved part and tip part concerning other examples for explaining an embodiment of the present invention. It is a perspective view of a 2nd node ring. It is a schematic diagram of the state by which the curved part was bent upward. It is a figure which shows the curved part which concerns on the modification of this invention.

With reference to FIGS. 1-10, an example of the endoscope for demonstrating embodiment of this invention is demonstrated.
FIG. 1 is an external view of a direct-view endoscope 1. The endoscope 1 includes an operation unit 20 and an insertion unit 30 that is connected to the operation unit 20 at the proximal end side and is inserted into a body cavity (in particular, a bile duct). A universal cable 2 is connected to the operation unit 20, and the universal cable 2 is detachably connected to a control device (not shown) via a connector 3.

  The operation unit 20 includes angle knobs 21 and 22 that are operated for a bending operation, various operation buttons 23 relating to air / water supply, suction, imaging, and the like, and a forceps insertion port 24 into which a treatment tool such as forceps is inserted. And have. Two wires 211, 212, 221, 222 (shown in FIGS. 3, 5, and 6) are connected to each of the angle knobs 21, 22 via pulleys (not shown). These wires are included in each of the operation unit 20 and the insertion unit 30, and the end of each wire is fixed to the distal end portion 33 of the insertion unit 30.

  Each of the universal cable 2, the operation unit 20, and the insertion unit 30 includes various pipes, light guides, signal lines, and the like. Light emitted from the light source unit of the control device reaches the tip 33 through the light guide. Similarly, the air / water supply from the control device and the treatment tool inserted from the forceps insertion port 24 also reach the distal end portion 33 through the respective pipelines.

  The insertion part 30 is, in order from the operation part 20 side, a flexible part 31 having flexibility, a bending part 32 that bends like a two-dot chain line in FIG. And a tip portion 33 that changes the direction following the movement of the bending portion 32. The flexible portion 31 and the bending portion 32 are covered with an outer skin member 301 including a net, a rubber tube, and the like.

  FIG. 2 is a front view of the distal end portion 33. At the distal end portion 33, illumination light windows 331 and 332 guided by a light guide, an observation window 333 directed to the observation target portion, and a forceps channel connected to the forceps insertion port 24 (FIG. 1) are provided. An opening 334 as an end and a nozzle 335 attached to the air / water supply channel are provided. An objective lens (not shown) is provided on the back side of the observation window 333. The optical axis of this objective lens is orthogonal to the paper surface of FIG. An imaging element such as a CCD or CMOS that photoelectrically converts an optical image formed through the objective lens is provided inside the distal end portion 33. This image sensor is connected to a signal processing unit of the control device via a signal line.

FIG. 3 is a side view of the bending portion 32 with the outer skin member 301 removed. In FIGS. 3, 5, and 6, illustration of a conduit, a light guide, and the like included in the bending portion 32 is omitted.
The bending portion 32 has a plurality of first node rings 321 and a plurality of second node rings 322. The first joint ring 321 and the second joint ring 322 are arranged at a predetermined number ratio, and the base end side region A1 and the center line on the base end side from the center line CL that bisects the length of the curved portion 32. The number ratio is different in the tip side region A2 from the CL to the tip side. Since the first node ring 321 and the second node ring 322 have the same axial dimension (width), the first node ring 321 in each of the proximal end side region A1 and the distal end side region A2 having the same length is used. The total number of the second node rings 322 is equal. Therefore, the number ratio of the first node ring 321 and the second node ring 322 in each of the proximal end side region A1 and the distal end side region A2 is the second node ring 322 in each of the proximal end side region A1 and the distal end side region A2. In other words.

  In addition, when the center line CL is located on one node ring, it may be considered that this node ring is disposed in either one of the proximal end side region A1 and the distal end side region A2. It may be considered that it is not arranged in any of the areas A1 and A2. These are determined as appropriate.

  When the bending portion 32 is not bent, the axis BB of the bending portion 32 is a straight line. However, when the bending portion 32 is bent, the axes BB of the bending portion 32 are different from each other. It passes through the center of the circular cross section in each of the spaced apart portions, and becomes a curved line as a whole. Such a direction along the axis BB is referred to as a longitudinal direction in which the bending portion 32 extends.

  FIG. 4 is a perspective view of the first joint ring 321 and the second joint ring 322. The first node ring 321 is formed in a substantially cylindrical shape with a circular cross section. At one end in the axial direction Z (Z-axis direction) of the first node ring 321 along the longitudinal direction of the curved portion 32, a pair of connecting portions 321A and 321A into which the pins 320 (FIG. 3) are inserted are respectively connected to the first node. The ring 321 is formed on both sides in the diameter direction. Here, a rotating shaft is provided on the same axis as the pair of pins 320 inserted through the pair of connecting portions 321A and 321A. Similarly, a rotation shaft is provided for a pair of connecting portions 321B and 321B, which will be described later, and a pin 320 inserted through a pair of connecting portions 322A and 322A.

  At the other end in the Z-axis direction of the first node ring 321, a pair of connecting portions 321 </ b> B and 321 </ b> B through which the pins 320 are respectively inserted intersect with the direction connecting the other connecting portions 321 </ b> A and 321 </ b> A (here, orthogonal) Are formed on both sides in the direction of movement). That is, the rotation shafts on both axial sides of the first node ring 321 are orthogonal to each other along the X-axis direction as the first direction and the Y-axis direction as the second direction. The first direction and the second direction refer to directions in a state where the bending portion 32 is not bent.

  The second node ring 322 is formed in a substantially cylindrical shape with a circular cross section, and a pair of connecting portions 322A and 322A through which the pin 320 is inserted are respectively provided at both ends in the axial direction (Z-axis direction) of the second node ring 322. Is formed. When the second node ring 322 and the first node ring 321 are connected, the connection portions 322A and 322A of the second node ring 322 are connected to the connection portions 321A and 321A of the first node ring 321, respectively. That is, the rotation shafts on both axial sides of the second joint ring 322 are provided in parallel to each other along the X-axis direction.

FIG. 5 is a cross-sectional view of the bending portion 32 in the base end region A1. The first node ring 321 is continuously arranged in the base end region A1, and the second node ring 322 is not arranged in the base end region A1. Since the rotation axes on both sides in the Z-axis direction of the first node ring 321 are orthogonal to each other, the rotation direction of the first node ring 321 is relative to the first node ring 321 adjacent to one end side in the Z-axis direction. The direction around the X axis (X rotation direction) is the direction around the Y axis (Y rotation direction) with respect to the first node ring 321 adjacent to the other end side in the Z axis direction.
Since the first node ring 321 has a curved shape with the rotation axis as a vertex, a gap SP is formed between the adjacent first node rings 321 and 321. By this gap SP, the relative rotation angle between the first joint rings 321 can be increased.

FIG. 6 is a cross-sectional view of the bending portion 32 in the distal end side region A2. In the front end side region A2, the first node rings 321 are connected to each other, the first node ring 321 and the second node ring 322 are connected to each other, and the second node rings 322 are connected to each other. The first node ring 321 and the second node ring 322 are arranged in a predetermined order. In this configuration, in the distal end side region A2, the number of rotating shafts extending along the first direction (X-axis direction) is larger than the number of rotating shafts extending along the second direction (Y-axis direction). .
A connection portion 322A of the second node ring 322 connected to the first node ring 321 is connected to a connection portion 321A that rotates in the X rotation direction of the first node ring 321. Since the second node ring 322 is also provided with a curve having the rotation axis as a vertex, the relative rotation angle between the first node ring 321 and the second node ring 322, and the relationship between the second node rings 322, The relative rotation angle can be increased.

  The pin 320 is caulked to the outer peripheral surface of each of the connecting portions 321A, 321B, and 322A. A guide hole through which a wire or the like is inserted is formed in a portion where the pin 320 protrudes inside the coupling portions 321A, 321B, and 322A.

  5 and 6 show three wires 211, 212, and 221, respectively. The two wires 211 and 212 interlocked with the angle knob 21 are inserted into the connecting portions 321B and 321B of the first node ring 321, respectively. In addition, two wires (one of which is the wire 221 shown in FIGS. 5 and 6) interlocking with the angle knob 22 are connected to the connecting portions 321A and 321A of the first node ring 321 and the second node ring 322, respectively. The parts 322A and 322A are inserted. The tips of these four wires are fixed inside the tip portion 33, respectively.

When the angle knob 21 is operated, one of the two wires 211 and 212 is pulled, and each of the first node ring 321 and the second node ring 322 rotates in the X rotation direction. Since the rotation angles of the first node ring 321 and the second node ring 322 are integrated, the bending portion 32 is bent upward or downward as a whole, and the direction of the distal end portion 33 is increased following this. Change to direction or down.
When the angle knob 22 is operated, one of the two wires 221 and 222 is pulled, and the first node ring 321 rotates in the Y rotation direction. As a result, the rotation angle of the first node ring 321 is integrated, so that the bending portion 32 is bent in the left direction or the right direction as a whole, and the direction of the tip portion 33 is changed to the left direction or the right direction following this. Is done.
Note that the bending direction of the bending portion 32 is referred to as the up and down direction and the left and right direction assuming that the subject is mainly lying down. For example, when the bending portion 32 extends along the vertical direction, the horizontal plane The X direction and the Y direction are the vertical direction and the horizontal direction, respectively.

  7A to 7C schematically show the bending state of the bending portion 32 in the vertical direction. When the angle knob 21 is operated, the first node ring 321 and the second node ring 322 rotate in the X rotation direction with the rotation axis in the X axis direction as the rotation center. At this time, the first node rings 321 connected via the rotation axis in the Y-axis direction do not relatively rotate. That is, the first node ring 321 rotates with respect to the adjacent node ring only on one side in the axial direction. On the other hand, the second node ring 322 rotates with respect to the adjacent node ring on both sides in the width direction.

  The axial dimension (width) and diameter dimension of each of the first node ring 321 and the second node ring 322, the distance between adjacent node rings, and the like are the same. From the arrangement state of the first joint ring 321 and the second joint ring 322 described above, the number of the second joint rings 322 disposed in the distal end side region A2 is the second joint ring disposed in the proximal end region A1. Since the number is larger than the number of 322, the ratio of the curvature radii of the distal end side region A2 and the proximal end region A1 is the number ratio of the second node rings 322 of each other.

  Therefore, the minimum curvature radius R2 of the distal end side region A2 alone shown in FIG. 7C is smaller than the minimum curvature radius R1 of the proximal end region A1 alone shown in FIG. 7B. That is, the bending portion 32 when bent in the vertical direction is bent in a state in which the radius of curvature is smaller on the tip side as shown in FIG. ing.

  FIG. 8 schematically shows a bending state of the bending portion 32 in the left-right direction. When the angle knob 22 is operated, only the rotation axis in the Y-axis direction is the rotation center, and the first node rings 321 are rotated in the Y-rotation direction. Since the number of the first node rings 321 arranged in the distal end side region A2 is smaller than the number of the first node rings 321 arranged in the proximal end region A1, the bending portion 32 when bent in the left-right direction is used. Is curved in a state in which the radius of curvature is larger on the distal end side than on the proximal end side.

  When the bending operation in the vertical direction and the bending operation in the horizontal direction are performed at the same time, the bending operation in FIG. 7A and the bending operation in FIG. 8 are combined, and the distal end portion 33 is in the vertical direction and in the horizontal direction. Get dumped. As described above, when the second node ring 322 is arranged in the distal end side region A2 when the swinging is performed in the up and down direction and the left and right direction, bending in the left and right direction in the distal end side region A2 is suppressed. That is, if a bending operation in the left-right direction is performed in a state where the distal end side region A2 close to the distal end portion 33 is sufficiently bent in the vertical direction, the distal end portion 33 is mainly bent by the lateral bending in the proximal end region A1. Since it is swung to the left and right, a pivot operation for turning the bending portion 32 around the observation site is possible. This makes it easier to fit the observation site within the field of view of the objective lens.

  FIG. 9 is a schematic view of the vicinity of the duodenum and a part of the duodenum cut out. The insertion portion 30 of the endoscope 1 is inserted from the oral cavity or nasal cavity and reaches the duodenum 11 that communicates with the stomach 10. In the vicinity of the duodenum 11, a liver 12, a gallbladder 13, and the like are provided. A bile duct 14 is opened on the inner wall of the duodenum 11, and the opening portion of the bile duct 14 is a duodenal papilla 111 having a narrowed shape. The pancreatic duct 15 joins the bile duct 14.

  When the distal end portion 33 is inserted into the bile duct 14, the bending portion 32 is bent by the operation of the angle knobs 21 and 22, and the distal end portion 33 is directed toward the duodenal papilla 111. In particular, the angle knob 21 is used to bend the curved portion 32 in the vertical direction, usually upward, so that the distal end portion 33 can be easily inserted into the bile duct 14 before the duodenal papilla 111. At this time, since the bending portion 32 bends gently at the proximal end side and suddenly bends at the distal end side, the bending portion 32 is housed compactly in a state where the entire bending portion 32 is bent inside the duodenum 11 in a narrow space. In addition, since the distal end portion 33 does not hit the inner wall and the distance between the distal end portion 33 and the inner wall can be secured, the distal end portion 33 can be easily directed to the duodenal papilla 111. As described above, the distal end portion 33 can be swung in the direction in which the duodenal papilla 111 is looked up along the extending direction of the bile duct 14 while the duodenal papilla 111 is in the visual field by pivoting the bending portion 32 or the like. The tip 33 can be easily inserted into the bile duct 14.

  FIG. 10 shows a state in which the distal end portion 33 is inserted into the bile duct 14 through the duodenal papilla 111. If necessary, the angle knobs 21 and 22 are operated to change the bending angle of the bending portion 32, and the distal end portion 33 is moved inside the bile duct 14 for observation and treatment. When a treatment is performed, a treatment tool is supplied through a forceps channel.

Next, another example of an endoscope for explaining an embodiment of the present invention will be described with reference to FIGS. In addition, about the structure similar to the structure mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted.
FIG. 11 is a side view of the bending portion 42 and the distal end portion 33. FIG. 12 is a perspective view of the second joint ring 422. The first node ring 321 is continuously arranged in the base end region A1 as in the configuration in the above-described example. On the other hand, the first node ring is not disposed in the distal end side region A2, and a plurality of second node rings 422 are continuously disposed.
A pair of connecting portions 422A and 422A are formed at both axial ends of the second node ring 422, respectively. These connecting portions 422A and 422A are formed at positions deviating from the diameter direction of the second node ring 422. The rotation shaft provided on the same axis of the pair of pins 320 inserted through the connecting portions 422A and 422A does not pass through the center of the cross section orthogonal to the axis BB of the bending portion 42 (or the second node ring 422). Pass through a position eccentric from the center. That is, each rotation shaft of the second node ring 422 disposed in the distal end side region A2 passes through a position eccentric from the center to the same side.

  A third joint ring 423 for connecting the first joint ring 321 and the second joint ring 422 is disposed in the vicinity of the boundary between the base end side area A1 and the distal end side area A2. At both ends in the axial direction of the third node ring 423, a connection part 321A connected to the first node ring 321 and a connection part 422A connected to the second node ring 422 are formed.

  Inside the distal end portion 33, an objective lens 336 provided on the back side of the observation window 333 (FIG. 2), a prism 337 that bends the observation image formed through the objective lens 336, and the observation image are photoelectrically converted. An image sensor 338 such as a CCD or CMOS is provided. The objective lens 336 is provided at a position decentered from the center of the distal end portion 33 when the distal end portion 33 is viewed from the front. The optical axis LA of the objective lens 336 is set on a surface including the rotation axes of the plurality of second node rings 422 disposed in the distal end side region A2 in a state where the bending portion 42 is not bent. That is, the optical axis LA is orthogonal to these rotation axes. That is, the optical axis LA of the objective lens 336 is on the extension in the direction of arrangement of the rotation shaft of the second node ring 422.

  As shown in FIG. 11, two wires in the left-right direction (one wire 221 is shown) are provided in the same manner as in the above-described example. On the other hand, the wire 211 relating to the bending in the vertical direction is the same as the side where the rotation axis of the second joint ring 422 disposed in the distal end side region A2 is eccentric from the center of the cross section perpendicular to the axis BB of the bending portion 42. The wire 211 is provided only on the side, and the position of the wire 211 is set to a position outside the second joint ring 422 with respect to the rotation axis of the second joint ring 422 disposed in the distal end side region A2. That is, the distance from the wire 211 to the center of the cross section of the bending portion 42 is larger than the distance from the rotation axis of the second node ring 422 disposed in the distal end side region A2 to the center of the cross section of the bending portion 42. That is, with respect to the vertical direction, only one wire 211 is provided above the axis BB, thereby limiting the direction of the bending operation with respect to the vertical direction to one direction. Although not shown in FIG. 12, a pipe or the like through which the wire 211 is inserted is fixed to the inner peripheral surface of the portion laid between the connecting portions 422 </ b> A of the second node ring 422.

Here, the path from the oral cavity or nasal cavity into which the insertion unit 30 is inserted to the duodenum 11 is relatively simple, and when the duodenal papilla 111 is in view, the direction of looking up at the duodenal papilla 111, that is, upward bending It is enough if the operation is possible. Therefore, by providing only one wire 211 in the upward direction and omitting the wire in the downward direction, the diameter of the insertion portion 30 can be reduced. If two wires 221 and 222 are used as in the left-right direction, when the pulling of one wire is released, the bending portion 42 is restored by using the tension of the other wire. When the pulling of the wire 211 is released when only the wire 211 is present, the bending portion 42 is restored by the elasticity of the forceps channel and the outer skin member 301.
The number of wires related to the upward bending operation is not limited to one. For example, two or three wires related to the upward bending operation are provided at positions adjacent to each other on the cross-sectional circumference of the bending portion. It may be done.
Further, the direction of the bending operation may be limited to the lower direction among the vertical directions. That is, the wire pulled in the up and down bending operation in which the bending portion 42 is bent by the rotation of the first node ring 321 and the second node ring 422 with the first direction as the rotation center is the tip side region. The rotational axis of the second node ring 422 arranged at A2 may be provided only on the side opposite to the side eccentric from the center of the cross section of the bending portion 42 (that is, on the lower side (−Y direction side)). Also in this case, the diameter of the insertion portion 30 can be reduced.

FIG. 13 schematically shows a state in which the bending portion 42 is bent upward by pulling the wire 211 by the operation of the angle knob 21. The bending portion 42 is bent with the side on which the rotation shafts of the second joint ring 422 are arranged as the inside of the curve. As described above, since the bending portion 42 is bent by pulling the wire 211 on the side where the rotation axis of the second joint ring 422 is eccentric, the curvature radius on the distal end side of the bending portion 42 becomes smaller, and the small turning performance is improved. It can be improved further.
In addition, the optical axis LA of the objective lens 336 is on a plane including the rotation axes of the plurality of second node rings 422 arranged on the tip side (the optical axis LA is orthogonal to each rotation axis). Therefore, the amount of deflection of the objective lens 336 during the upward bending operation can be minimized. That is, since each rotation axis of the second node ring 422 is decentered according to the optical axis of the objective lens, the movement of the viewpoint is suppressed. For this reason, the direction of the visual field can be changed smoothly. In addition, since it is difficult to reduce the curvature radius (curvature radius at the time of bending downward) when the second joint ring 422 is bent with the side on which the rotation shafts are aligned as the curved outside, it is difficult to reduce the curvature of the second joint ring 422. It is preferable to reduce the diameter of the insertion portion 30 by omitting the wire provided on the side opposite to the side where the rotation shaft is eccentric.

  FIG. 14 shows a bending portion 52 according to a modified example of the configuration described above. The curved portion 52 has a second joint ring 522 having a shorter axial length (width) than the first joint ring 321. Since the second node ring 522 is continuously arranged in the distal end side region A2, the radius of curvature on the distal end side is further reduced, so that the turning performance can be improved. The arrangement of the nodal rings arranged in the distal end side region A2 can be appropriately designed, and if necessary, the second nodal ring 322 described above is continuously arranged in the proximal end side portion in the distal end side region A2, It is good also as a structure by which the 2nd node ring 522 with a narrow width | variety is continuously arrange | positioned in the part of the front end side in front end side area | region A2. As a result, the bending portion 52 can be further bent sharply at the position on the distal end side. Note that it is also conceivable to gradually reduce the width of the second node ring from the proximal end side toward the distal end side.

  Although the second joint ring is not arranged in the base end side region A1 in the above-described configuration (see FIGS. 3, 12, and 14), the length of the bending portion is not limited to this, and the length of the bending portion is divided into two equal parts. A second node ring may be disposed on the base end side from the center line. Further, in the distal end side region A2 of FIG. 3, the node rings are arranged in the order that two first node rings 321 are continuous and then two second node rings 322 are continuous. One second node ring may be arranged after two one node rings continue. Moreover, you may comprise so that the number of 2nd node rings may gradually increase toward the front end side from a base end side. In this case, the ratio of the number of node rings has a gradient from the proximal end side toward the distal end side. In short, when the distal end side region and the proximal end side region are assumed, it is sufficient that the number of second joint rings in the distal end side region is larger than the number of second joint rings in the proximal end side region.

In the above, for clarification of the configuration, the proximal side region and the distal side region with the center line as a boundary are assumed, and the description has been made using the number of second joint rings included in each of these regions. The technical idea of the present invention is that the arrangement density of the first joint ring and the second joint ring is made different between the proximal end side and the distal end side, thereby making the curvature radius different between the proximal end side and the distal end side. is there. Here, factors that change the radius of curvature include the width of each of the first and second joint rings (the length in the axial direction), the gap formed between the joint rings, and the like. This is considered to be a matter. Further, the diameter of the node ring, specifically, the distance from the position of the pin to the outer periphery of the node ring also affects the curvature radius. In short, it is possible to add various considerations to the arrangement, shape, dimensions, etc. of the node rings in the region where the radius of curvature is desired to be reduced.
In addition, the number of node rings can be paraphrased by the number of connecting portions. Further, the joint portion of the node ring is not limited to being integrally formed with the cylindrical node ring main body, and may be separated from the node ring main body.

Not only the direct-view type but also a side-view type endoscope can be used to improve the small turning performance. The site to be observed and treated may be the esophagus, pharynx, gastrointestinal tract, etc. in addition to the bile duct and pancreatic duct, and is not limited.
The configuration of the imaging system is not limited to that having a CCD, a CMOS, or the like.

As described above, the following items are disclosed in this specification.
(1) An endoscope including a bending portion that is inserted into a body cavity from the distal end side and bent by a bending operation,
The bending portion has a plurality of node rings that are rotatably connected to each other,
The plurality of node rings are provided with a pivot shaft extending along a first direction intersecting a longitudinal direction in which the curved portion extends, at one end in the longitudinal direction, and in both the longitudinal direction and the first direction. A rotation shaft extending along the intersecting second direction has a first node ring provided at the other end in the longitudinal direction, and a rotation shaft extending in parallel with each other along the first direction at each end in the longitudinal direction. And a second joint ring provided,
The number of rotating shafts extending along the first direction disposed on the distal end side of the bending portion is greater than the number of rotating shafts extending along the first direction disposed on the proximal end side of the bending portion. There are many endoscopes.

  According to this endoscope, the curvature radius on the distal end side can be made smaller than the curvature radius on the proximal end side with respect to the bending direction with the first direction as the rotation center, and can be curved into a shape suitable for a narrow space. Therefore, operability can be improved.

(2) An endoscope including a bending portion that is inserted into a body cavity from the distal end side and bent by a bending operation,
The bending portion has a plurality of node rings that are rotatably connected to each other,
The plurality of node rings are provided with a pivot shaft extending along a first direction intersecting a longitudinal direction in which the curved portion extends, at one end in the longitudinal direction, and in both the longitudinal direction and the first direction. A rotation shaft extending along the intersecting second direction has a first node ring provided at the other end in the longitudinal direction, and a rotation shaft extending in parallel with each other along the first direction at each end in the longitudinal direction. And a second joint ring provided,
The number of rotating shafts extending along the first direction arranged on the distal end side of the bending portion is larger than the number of rotating shafts extending along the second direction arranged on the distal end side of the bending portion. Many endoscopes.
According to this endoscope, the curvature radius on the distal end side can be made smaller than the curvature radius on the proximal end side with respect to the bending direction with the first direction as the rotation center, and can be curved into a shape suitable for a narrow space. Therefore, operability can be improved.

(3) The endoscope according to (1) or (2),
An endoscope in which each of the rotation shafts of the second joint ring arranged on the distal end side passes through a position eccentric to the same side from the center of the cross section of the bending portion orthogonal to the longitudinal direction.
According to this endoscope, the curvature radius on the distal end side can be reduced when the side on which the rotation axis of the second node ring on the distal end side is bent is the inner side.

(4) The endoscope according to (3),
An objective lens having an optical axis along the longitudinal direction in a state where the bending portion is not bent is provided at the distal end portion of the endoscope,
An endoscope in which an optical axis of the objective lens is set on a surface including rotation axes of a plurality of the second joint rings arranged on the distal end side in a state where the bending portion is not bent.
According to this endoscope, by inserting the endoscope insertion part directly into a particularly thin part such as a bile duct, both observation and treatment for the thin part can be realized at the same time, and the second articular ring can be rotated. Since the movement of the viewpoint is suppressed when the side on which the shaft is eccentric is curved inward, the operability can be improved.

(5) The endoscope according to (3) or (4),
A linear member to be pulled during a bending operation in which the bending portion is bent by the rotation of each node ring with the first direction as a rotation center is provided on the second node ring disposed on the distal end side. The rotation axis is provided only on the same side as the side deviated from the center of the cross section of the curved portion orthogonal to the longitudinal direction, and the distance from the linear member to the center of the cross section is disposed on the tip side. An endoscope that is larger than the distance from the rotation axis of the second node ring to the center of the cross section.
According to this endoscope, the linear member that is normally provided on the side opposite to the side on which the rotation axis of the second joint ring is eccentric can be omitted, thereby reducing the diameter of the insertion portion.

(6) The endoscope according to (3) or (4),
A linear member to be pulled during a bending operation in which the bending portion is bent by the rotation of each node ring with the first direction as a rotation center is provided on the second node ring disposed on the distal end side. An endoscope which is provided only on a side opposite to a side where a rotation axis is decentered from a center of a cross section of the curved portion perpendicular to the longitudinal direction.
According to this endoscope, the linear member provided on the same side as the side where the rotation shaft of the second joint ring is eccentric can be omitted, and thereby the diameter of the insertion portion can be reduced.

(7) The endoscope according to any one of (1) to (5),
An endoscope in which a plurality of the second node rings are continuously arranged on the distal end side.
According to this endoscope, the density of the rotation shaft in the first direction is increased compared to the case where the second node rings are not continuous, so the first direction of the portion where the second node rings are arranged is the rotation center. The bending angle obtained by integrating the rotation angle is increased. Thereby, the radius of curvature on the tip side can be further reduced.
In addition, it is not necessary that all the second joint rings arranged in the tip side region are continuously arranged on the tip side. Even when the second joint ring is continuously arranged only in a part of the tip side region, the radius of curvature can be reduced with respect to the continuous part.

(8) The endoscope according to any one of (1) to (7),
An endoscope in which a dimension in the longitudinal direction of the second joint ring disposed on the distal end side is smaller than a dimension in the longitudinal direction of the first joint ring.
According to this endoscope, the radius of curvature on the distal end side can be further reduced by the smaller width dimension.

(9) The endoscope according to any one of (1) to (8),
An endoscope in which a distal end portion of the endoscope is provided with an objective lens having an optical axis along the longitudinal direction in a state where the bending portion is not bent.
According to this endoscope, by directly inserting the endoscope insertion portion into a particularly thin portion such as a bile duct, both observation and treatment for the thin portion can be realized at the same time.

DESCRIPTION OF SYMBOLS 1 Endoscope 2 Universal cable 3 Connector 20 Operation part 21,22 Angle knob 30 Insertion part 31 Soft part 32 Bending part 33 Bending part 42 Bending part 52 Bending part 211,212,221,222 Wire 301 Outer member 320 Pin 321 1st First Node Ring 321A Connection Portion 321B Connection Portion 322 Second Node Ring 322A Connection Portion 333 Observation Window 336 Objective Lens 337 Prism 338 Image Sensor 422 Second Node Ring 422A Connection Portion 423 Third Node Ring 522 Second Node Ring A1 Base End Side Area A2 Tip side area BB Axis line CL Center line LA Optical axis

Claims (7)

An endoscope comprising a bending portion that is inserted into a body cavity from the distal end side and bent by a bending operation,
The bending portion has a plurality of node rings that are rotatably connected to each other,
The plurality of node rings are provided with a pivot shaft extending along a first direction intersecting a longitudinal direction in which the curved portion extends, at one end in the longitudinal direction, and in both the longitudinal direction and the first direction. A rotation shaft extending along the intersecting second direction has a first node ring provided at the other end in the longitudinal direction, and a rotation shaft extending in parallel with each other along the first direction at each end in the longitudinal direction. And a second joint ring provided,
The number of rotating shafts extending along the first direction disposed on the distal end side of the bending portion is greater than the number of rotating shafts extending along the first direction disposed on the proximal end side of the bending portion. also rather large,
All of the rotation shafts of the second joint ring arranged on the distal end side pass through a position eccentric to the same side from the center of the cross section of the curved portion orthogonal to the longitudinal direction,
An objective lens having an optical axis along the longitudinal direction in a state where the bending portion is not bent is provided at the distal end portion of the endoscope,
An endoscope in which an optical axis of the objective lens is set on a plane including rotation axes of a plurality of second joint rings arranged on the distal end side in a state where the bending portion is not bent . An endoscope comprising a bending portion that is inserted into a body cavity from the distal end side and bent by a bending operation,
The bending portion has a plurality of node rings that are rotatably connected to each other,
The plurality of node rings are provided with a pivot shaft extending along a first direction intersecting a longitudinal direction in which the curved portion extends, at one end in the longitudinal direction, and in both the longitudinal direction and the first direction. A rotation shaft extending along the intersecting second direction has a first node ring provided at the other end in the longitudinal direction, and a rotation shaft extending in parallel with each other along the first direction at each end in the longitudinal direction. And a second joint ring provided,
The number of rotating shafts extending along the first direction arranged on the distal end side of the bending portion is larger than the number of rotating shafts extending along the second direction arranged on the distal end side of the bending portion. rather large,
All of the rotation shafts of the second joint ring arranged on the distal end side pass through a position eccentric to the same side from the center of the cross section of the curved portion orthogonal to the longitudinal direction,
An objective lens having an optical axis along the longitudinal direction in a state where the bending portion is not bent is provided at the distal end portion of the endoscope,
An endoscope in which an optical axis of the objective lens is set on a plane including rotation axes of a plurality of second joint rings arranged on the distal end side in a state where the bending portion is not bent . The endoscope according to claim 1 or 2 , wherein
A linear member to be pulled during a bending operation in which the bending portion is bent by the rotation of each node ring with the first direction as a rotation center is provided on the second node ring disposed on the distal end side. The rotation axis is provided only on the same side as the side deviated from the center of the cross section of the curved portion orthogonal to the longitudinal direction, and the distance from the linear member to the center of the cross section is disposed on the tip side. An endoscope that is larger than the distance from the rotation axis of the second node ring to the center of the cross section. The endoscope according to claim 1 or 2 , wherein
A linear member to be pulled during a bending operation in which the bending portion is bent by the rotation of each node ring with the first direction as a rotation center is provided on the second node ring disposed on the distal end side. An endoscope which is provided only on a side opposite to a side where a rotation axis is decentered from a center of a cross section of the curved portion perpendicular to the longitudinal direction. The endoscope according to any one of claims 1 to 4 ,
An endoscope in which a plurality of the second node rings are continuously arranged on the distal end side. The endoscope according to any one of claims 1 to 5 ,
An endoscope in which a dimension in the longitudinal direction of the second joint ring disposed on the distal end side is smaller than a dimension in the longitudinal direction of the first joint ring. The endoscope according to any one of claims 1 to 6 ,
An endoscope in which a distal end portion of the endoscope is provided with an objective lens having an optical axis along the longitudinal direction in a state where the bending portion is not bent.

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