JP5317874B2 - Endoscope and endoscope system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a position and an orientation of a distal end portion of an insertion portion by providing two magnetic elements at the distal end portion without increasing a diameter of the insertion portion of an endoscope. <P>SOLUTION: Two magnetic elements 60 are provided at the distal end portion 14 of the insertion portion 12 of the endoscope 10 on a nonconcentric axis. A channel tube 41 which occupies the largest area in the distal end portion 14 is disposed eccentrically on one side relative to an axis center of the insertion portion 12. Two magnetic elements 60 and an illumination light emitting part 23 and an objective optical system 31 both of which are small buried articles are juxtaposed circumferentially in a semiperimeter part on the side opposite from the eccentric side where the channel tube 41 is disposed. At least one of the small buried articles 23, 31 is kept between two magnetic elements 60. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an endoscope and an endoscope system that are inserted into a subject for diagnosis, treatment, and the like, and more particularly to an endoscope and an endoscope system having a function of detecting the position of an insertion portion and the like.

  An endoscope has an insertion portion extending from a main body portion (see Patent Document 1). The insertion part is inserted into the subject to perform diagnosis, treatment, and the like. A bending portion is provided at the distal end portion of the insertion portion. The bending portion can be bent remotely by the knob of the main body. A channel tube, an image guide, and a light guide are generally provided inside the insertion portion. The image guide and the light guide are constituted by optical fibers, for example. The channel tube and the light guide reach the distal end surface of the insertion portion. Further, an objective optical system is provided at the distal end of the insertion portion, and an image guide is optically connected to the objective optical system. Illumination light is emitted from the tip of the insertion portion along the light guide, and illuminates the observation target. An image to be observed enters the objective optical system, is transmitted to the main body through the image guide, and can be observed with an eyepiece or a monitor. A surgical instrument such as forceps is passed through the channel tube. Usually, the channel tube has a considerably larger diameter than the image guide and the light guide made of an optical fiber, and the ratio of the channel tube to the insertion portion is large.

A technique for detecting the position and shape of the insertion portion inserted into the subject is known.
For example, in the detection system described in Patent Document 2, a magnetic element made of a coil is provided in a probe such as an endoscope. Detection means including a magnetic field source composed of a plurality of coils is installed outside. The plurality of coils of the magnetic field source are oriented in different predetermined directions. A magnetic field is generated from each coil of the magnetic field source. An electromotive force is induced in the magnetic element according to each magnetic field. A detection signal corresponding to the induced electromotive force is sent to the controller of the detection means. The controller analyzes the position and orientation of the probe based on this detection signal. The position can be displayed in three-dimensional orthogonal coordinates (x, y, z). The orientation includes the direction of extension of the probe axis and the angle around the axis. The extension direction of the shaft can be displayed in polar coordinates (φ, θ). Further, in order to detect the angle (ψ) about the axis, two magnetic elements are provided non-coaxial with each other in the probe.
A magnetic field may be generated from the magnetic element by energizing a coil constituting the magnetic element. In this case, the external magnetic field source becomes a magnetic field detector. A magnetic field from the magnetic element is detected by a plurality of coils of the magnetic field detector.

  In the detection system described in Patent Document 3, a plurality of magnetic elements are provided at intervals in the longitudinal direction of the insertion portion, and the shape of the insertion portion is detected from position data of each magnetic element.

  In Patent Document 4, when an endoscope is inserted up to a target point in a bronchus, for example, three-dimensional image data of the subject is created by a computer based on a plurality of tomographic images of the subject, and the three-dimensional It is described that a route to a target point is obtained along the bronchial duct on the image of the above and a guide image is displayed on the monitor. On the monitor, the guide image is displayed together with the live image taken by the endoscope. The surgeon can determine on the basis of the guide image which branching path should be taken whenever the distal end of the endoscope reaches the branch point of the bronchus.

JP 2008-206699 A International Publication WO2003 / 001244 Japanese Patent Laid-Open No. 06-285043 JP 2000-135215 A

For example, when an endoscope is used for treatment of a lesion in the brain, it is required to insert the insertion portion to a target point in the brain without damaging the brain tissue. For that purpose, it is important to accurately grasp where the distal end of the insertion portion is located in the brain chamber and where it is facing. Regarding the orientation of the insertion portion, it is preferable that the angle about the axis can be grasped as well as the extension direction of the insertion portion. That is, for example, when the bending portion at the distal end of the insertion portion is remotely operated, if the angle around the axis of the insertion portion is uncertain, the bending portion may bend in an unintended direction and damage brain tissue. In order to detect the angle around the axis of the insertion portion, it is necessary to provide two magnetic elements in the insertion portion as described in Patent Document 2. However, if two magnetic elements are arranged in the vicinity of each other, the arrangement space for these magnetic elements becomes bulky and the diameter of the entire insertion portion becomes large. If the insertion part has a large diameter, the burden on the patient is large.
Accordingly, the present invention can detect the position of the distal end portion of the insertion portion, the extension direction, and the angle around the axis without increasing the diameter of the insertion portion of the endoscope, by providing two magnetic elements at the distal end portion. The purpose is to.

In view of the above circumstances, an endoscope according to the present invention has a flexible insertion portion extending in a strip shape, and has a distal end portion of a channel tube, an objective portion of an image transmission system, and illumination light as an embedded object at the distal end of the insertion portion. In the endoscope in which the emitting part is embedded and the occupied area of either one of the tip part of the channel tube and the objective part at the tip of the insertion part is larger than that of the small embedded object,
Two magnetic elements for detecting the position and orientation of the distal end of the insertion part by detecting or generating a magnetic field are provided non-coaxially at the distal end of the insertion part, and the cross-sectional area of each magnetic element is smaller than the occupied area. The maximum embedded object is arranged eccentric to one side with respect to the axis of the insertion part at the tip of the insertion part, and the two magnetic elements and the small embedded object are arranged on the eccentric side of the maximum embedded object. Are arranged side by side in the circumferential direction of the opposite half-circumferential portion, and at least one of the small buried objects is sandwiched between the two magnetic elements.
In addition, an endoscope system according to the present invention has a flexible insertion portion extending in a strip shape, and has a distal end portion of a channel tube, an objective portion of an image transmission system, and an illumination light emitting portion as an embedded object at the distal end of the insertion portion. And an endoscope in which the occupation area of either one of the tip of the channel tube and the objective at the tip of the insertion part is larger than that of a small buried object,
Detection means for detecting the position and orientation of the tip of the insertion part by generating or detecting a magnetic field;
Two magnetic elements connected to the detection means for detecting or generating a magnetic field are provided non-coaxially at the distal end of the insertion part, and the cross-sectional area of each magnetic element is smaller than the occupied area, and the insertion part The maximum embedded object is arranged eccentric to one side with respect to the axis of the insertion portion at the tip of the insertion part, and the two magnetic elements and the small embedded object are opposite to the eccentric side of the maximum embedded object. It is arranged side by side in the circumferential direction of the half-circumferential portion, and at least one of the small embedded objects is sandwiched between the two magnetic elements.

  According to the present invention, two magnetic elements are further accommodated in the distal end portion of the insertion portion of the endoscope, in addition to the illumination light emitting portion, the objective portion of the image transmission system, and the distal end portion of the channel tube. It is possible to prevent the insertion portion from increasing in diameter. Therefore, the burden on the patient can be reduced. By disposing the two magnetic elements non-coaxially, it is possible to detect not only the position and extension direction of the distal end portion of the insertion portion, but also the angle around the axis of the insertion portion. By sandwiching at least one of the small embedded objects including the illumination light emitting part between the two magnetic elements, the two magnetic elements can be arranged as far apart as possible. Thereby, the analysis accuracy of the angle around the axis of the insertion portion can be increased. Therefore, when the bending portion of the insertion portion is bent, the bending direction can be accurately determined. As a result, for example, in the treatment of a lesion in the brain, the insertion portion can be inserted up to the target point of the ventricle, for example, without damaging the brain tissue.

More preferably, the entire small buried object is sandwiched between the two magnetic elements. As a result, the two magnetic elements can be reliably separated and the angle analysis accuracy around the axis of the insertion portion can be reliably increased.
It is preferable that the outer diameter of the maximum embedded object is, for example, one half or more of the outer diameter of the insertion portion.
The maximum buried object is, for example, a channel tube.
The objective part of the image transmission system includes an objective optical system including, for example, an objective lens. Preferably, the image transmission system includes the objective optical system and an image guide that transmits an optical image incident on the objective optical system. In this case, the area occupied by the objective part can be made smaller than the tip part of the channel tube. The objective part of the image transmission system may include an objective optical system and an image sensor. The objective part including the imaging element may have an occupied area larger than the tip part of the channel tube, and in this case, the objective part becomes the maximum embedded object.
A plurality of the illumination light emitting portions may be arranged at the distal end of the insertion portion. For example, two illumination light emitting units may be arranged so as to sandwich the objective optical system. Thereby, an observation object can be illuminated reliably. The two magnetic elements may be arranged so as to sandwich the two illumination light emitting units and the objective optical system.

  It is preferable that the two magnetic elements are separated from each other in the circumferential direction of the insertion portion by 30 ° or more and less than 180 ° around the axis of the insertion portion, and are preferably separated by about 60 ° or more and less than 180 °. More preferably, it is more preferably about 90 ° or more and less than 180 ° apart.

  According to the present invention, it is possible to detect the position of the distal end portion of the insertion portion, the extending direction, and the angle around the axis without increasing the diameter of the insertion portion of the endoscope.

It is a schematic structure figure of an endoscope system which looked at an endoscope from the front. It is a top view of the above-mentioned endoscope. It is the figure which looked at the front end surface of the insertion part of the above-mentioned endoscope by omitting the front end cap. It is sectional drawing of the front-end | tip part of the insertion part of the said endoscope which follows the step-like IV-IV line | wire of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an overview configuration of the endoscope system S. The endoscope system S includes an endoscope 10 and detection means 50. As shown in FIGS. 1 and 2, the endoscope 10 is formed in a strip shape from a main body portion 11, a cable 19 extending from an intermediate portion of the main body portion 11, and a distal end portion (right in FIG. 1) of the main body portion 11. And a flexible insertion portion 12 extending. The cable 19 is branched into a write cable 29 and a magnetic detection cable 69 on the way.

  The insertion part 12 is comprised with the flexible resin tube. A bending portion 13 is provided at the distal end portion of the insertion portion 12, and a distal end rigid portion 14 is further provided at the distal end side. A distal end cap 15 is provided at the distal end of the distal end rigid portion 14, that is, the most distal end of the insertion portion 12. As shown in FIG. 4, the cap 15 is provided with a plurality of hooks 15a. The hook 15a is detachably hooked on the engaging recess 14a on the inner peripheral surface of the outer wall of the distal end hard portion 14. Thereby, the cap 15 can be attached or detached.

  Although not shown, a plurality of joint rings are provided in the bending portion 13. These joint rings are arranged in a line and are connected by an operation wire. The operation wire is passed through the insertion portion 12 and the main body portion 11, and the base end portion is connected to the bending operation portion 16 of the main body portion 11. As shown by the two-dot chain line in FIG. 1 and FIG.

  As shown in FIG. 1, a light guide 22 (illumination light transmission means, omitted in FIG. 2) is accommodated in the cables 29 and 19, the main body 11, and the insertion portion 12. The light guide 22 is composed of a bundle of optical fibers. The proximal end portion of the light guide 22 is optically connected to the light source 20 via the plug 21 at the end portion of the cable 29. The distal end portion of the light guide 22 reaches the distal end rigid portion 14 and constitutes an illumination light emitting portion 23. As shown in FIG. 3, the distal end surface of the illumination light emitting portion 23 is exposed from the distal end cap 15. Illumination light emitted from the light source 20 is transmitted by the light guide 22 and emitted from the front end surface of the light guide 22 to illuminate the observation target.

  As shown in FIG. 2, an image transmission system 30 is accommodated inside the main body portion 11 and the insertion portion 12. The image transmission system 30 includes an objective optical system 31 (object section), an image guide 32, and an eyepiece 33. The objective optical system 31 includes an objective lens and the like, and is embedded in the distal end hard portion 14. As shown in FIG. 3, the tip surface of the objective optical system 31 is exposed from the tip cap 15. The image guide 32 is configured by one or a plurality of optical fibers and is accommodated in the main body 11 and the insertion portion 12. The tip of the image guide 32 is optically connected to the objective optical system 31. The proximal end portion of the image guide 32 is optically connected to an eyepiece 33 provided at the proximal end portion of the main body portion 11. An image to be observed enters the objective optical system 31 and is transmitted to the eyepiece 33 by the image guide 32. This optical image is converted into an electrical signal by a signal converter (not shown), further converted into a video signal, and displayed on a monitor. Of course, it is also possible for the practitioner to directly observe the image to be observed by looking into the eyepiece 33.

As shown in FIG. 2, a resin-made channel tube 41 (not shown in FIG. 1) is accommodated inside the main body 11 and the insertion portion 12. The proximal end portion of the channel tube 41 is connected to the forceps port 40 of the main body portion 11. The distal end portion of the channel tube 41 reaches the distal end rigid portion 14, and the distal end surface thereof is exposed from the distal end cap 15. A surgical instrument such as a forceps is inserted into the channel tube 41 from the forceps opening 40 and protrudes from the distal end of the insertion portion 12 to perform a desired operation. As shown in FIG. 3, the outer diameter of the channel tube 41 is larger than one half of the outer diameter of the insertion portion 12 and is considerably larger than the outer diameters of the light guide 22, the image guide 32, and the objective optical system 31. The occupied area of the distal end portion of the channel tube 41 at the distal end of the insertion portion 12 is sufficiently larger than the occupied areas of the illumination light emitting portion 23 and the objective optical system 31.
The distal end portion of the channel tube 41, the illumination light emitting portion 23, and the objective optical system 31 constitute an embedded object at the distal end portion of the insertion portion 12. The distal end portion of the channel tube 41 constitutes the maximum embedded object, and the illumination light emitting unit 23 and the objective optical system 31 each constitute a small embedded object.

  The endoscope system S has a function of detecting the position and orientation of the distal end portion of the insertion portion 12. More specifically, as shown in FIG. 1, the detection means 50 is connected to the endoscope 10. The detection means 50 includes a controller 51 and a magnetic field source 52 connected to the controller 51. Although not shown, the magnetic field source 52 is provided with a plurality of magnetic field coils at different positions. The axes of these magnetic field coils are directed in different predetermined directions. By sequentially energizing these magnetic field coils, a magnetic field is generated from the magnetic field source 52 in a plurality of predetermined directions. The magnetic field source 52 is preferably installed within the distal end portion of the insertion portion 12 of the endoscope 10 and thus within several tens of centimeters of the subject.

  Further, as shown in FIG. 1, two magnetic elements 60 and 60 are provided on the distal end rigid portion 14 of the insertion portion 12 of the endoscope 10. As shown in FIG. 4, each magnetic element 60 has a thin rod shape. The outer diameter of the magnetic element 60 is about 0.5 mm, for example, and the length of the magnetic element 60 is about 8 mm. Each magnetic element 60 has one magnetic field coil 63. A magnetic field coil 63 is embedded in a resin housing 64. The axis of the magnetic field coil 63 of each magnetic element 60 is parallel to the axis of the insertion portion 12. Two magnetic elements 60, 60 are arranged in parallel along the axis of the insertion portion 12. The magnetic elements 60 and 60 are displaced in at least one direction out of the circumferential direction of the insertion portion 12 and the direction orthogonal to the axis of the insertion portion 12 and are non-coaxial with each other. In this embodiment, the magnetic elements 60, 60 are displaced in the circumferential direction of the insertion portion 12 and are arranged non-coaxially. An induced electromotive force is generated in the magnetic field coil 63 in accordance with the magnetic field from the magnetic field source 52. Thereby, the magnetic element 60 can detect the magnetic field.

  As shown in FIG. 1, a magnetic signal line 65 extends from the base end portion of each magnetic element 60. The magnetic signal line 65 is passed through the insertion portion 12, the main body portion 11, and the cables 19 and 69, and is connected to the magnetic detection connector 67 at the end of the cable 69. A magnetic detection connector 67 is connected to the controller 51. As a result, each magnetic element 60 is connected to the controller 51.

  A magnetic field signal detected by each magnetic field element 60 is input to the controller 51 through a signal line 65 and further subjected to predetermined signal conversion. The controller 51 (analyzing means) analyzes the position and orientation of the distal end of the insertion portion 12 based on the detection signal of the magnetic element 60. The position of the tip of the insertion part 12 is represented by, for example, three-dimensional coordinates (x, y, z). The direction of the distal end of the insertion portion 12 includes the extending direction of the distal end of the insertion portion 12 and the angle around the axis of the insertion portion 12. The extending direction of the distal end of the insertion portion 12 is represented by, for example, polar coordinates (φ, θ). The angle around the axis of the insertion portion 12 is represented by, for example, a deviation angle (ψ) of a reference point on the outer periphery of the insertion portion 12 with respect to a predetermined direction orthogonal to the extension direction (polar coordinate vector).

  A personal computer 53 is connected to the controller 51. The analysis result of the controller 51 is automatically input to the computer 53. The computer 53 displays the position and orientation of the distal end of the insertion portion 12 as an image on the display based on the analysis result (x, y, z, φ, θ, ψ). Of course, the analysis result (x, y, z, φ, θ, ψ) may be displayed as a numerical value as it is. Images and numerical values may be displayed simultaneously on one display screen.

The magnetic element 60 is stored in the endoscope 10 as follows.
As shown in FIG. 4, a guide tube 66 is accommodated in the insertion portion 12. The guide tube 66 is made of a flexible resin. The distal end portion of the guide tube 66 has a slightly larger diameter. The magnetic element 60 is fitted into the large diameter portion 66 a at the tip of the guide tube 66. The magnetic signal line 65 is accommodated in the guide tube 66 on the proximal end side with respect to the large diameter portion 66a.

  As shown in FIGS. 3 and 4, a holder 17 is provided inside the distal end rigid portion 14 of the insertion portion 12. The holder 17 is made of resin and has a cylindrical shape. The holder 17 is formed with a plurality of receiving holes 17a to 17d having different sizes. These accommodation holes 17a to 17d penetrate in the axial direction of the cylindrical holder 17 (that is, the axial direction of the insertion portion 12). Two accommodation holes 17d are provided. The large-diameter portion 66a of the guide tube 66 is fitted into each housing hole 17d, so that the magnetic element 60 is housed and held. Thereby, the position of the magnetic element 60 is fixed in the distal end hard portion 14. The cross-sectional area of the magnetic element 60 is sufficiently smaller than the occupied area of the distal end portion of the channel tube 41 at the distal end of the insertion portion 12 even when combined with the cross-sectional area of the large diameter portion 66 a of the guide tube 66.

As shown in FIG. 3, the distal end portion of the channel tube 41 is accommodated and held in the largest accommodation hole 17 a of the holder 17.
The number of receiving holes 17b in the holder 17 is two. The distal end portion of the light guide 22, that is, the illumination light emitting portion 23 is accommodated and held in each accommodation hole 17b.
The objective optical system 31 is accommodated and held in the accommodation hole 17c.

  As shown in FIG. 3, at the distal end rigid portion 14, that is, at the distal end of the insertion portion 12, the distal end portion of the channel tube 41 is arranged eccentric to one side (left in FIG. 3) with respect to the axial center of the insertion portion 12. . The two magnetic elements 60, 60, the two illumination light emitting parts 23, 23 and the objective optical system 31 are arranged side by side in the circumferential direction of the half-circumferential portion of the channel tube 41 opposite to the eccentric side. Specifically, the objective optical system 31 is arranged on the side opposite to the eccentric side of the channel tube 41 by 180 °. Two illumination light emitting portions 23 and 23 are arranged so as to sandwich the objective optical system 31. The two magnetic elements 60 and 60 are arranged outside the illumination light emitting units 23 and 23 and the objective optical system 31 so as to sandwich the illumination light emitting units 23 and 23 and the objective optical system 31.

  The two magnetic elements 60 and 60 are separated from each other by 30 ° or more and less than 180 ° in the circumferential direction of the insertion portion 12 around the axis of the insertion portion 12. In this embodiment, the two magnetic elements 60 are separated by about 120 ° with the axis of the insertion portion 12 as the center. With the axis of the channel tube 41 as the center, the two magnetic elements 60 and 60 are separated by about 90 ° in the circumferential direction of the channel tube 41.

An example of how to use the endoscope system S will be described.
The endoscope system S is used, for example, for observation and treatment of the human ventricle. The head of the subject is tomographed in advance by MRI (magnetic resonance imaging apparatus) or CT (computer tomography apparatus). Based on the photographing data, the computer 53 generates three-dimensional image data of the head. Then, a route to the target point is determined on the 3D image data.

  When actually observing and treating the subject's ventricle using the endoscope 10, the insertion unit 12 is inserted into the brain while referring to the path on the three-dimensional image data. At this time, a magnetic field is generated from the magnetic field source 52. The two magnetic elements 60 and 60 detect this magnetic field, respectively. That is, an electromotive force having a magnitude corresponding to the position and orientation relative to the magnetic field source 52 is generated in the coil 63 of each magnetic element 60, and this is output as a detection signal. By reducing the diameter of the magnetic field coil 63 and increasing the axial length, the magnetic flux density crossing the coil 63 can be changed greatly according to the direction of the coil 63. Therefore, the sensitivity to the direction can be increased. A detection signal of each magnetic element 60 is input to the controller 51 via the magnetic signal line 65. The controller 51 obtains the position (x, y, z) and direction (φ, θ, ψ) of the distal end portion of the insertion portion 12 based on the detection signal. By arranging the two magnetic elements 60 and 60 non-coaxially, not only the position (x, y, z) and extension direction (φ, θ) of the distal end portion of the insertion portion 12 but also the axis center of the insertion portion 12 is arranged. The angle (ψ) can also be detected. By disposing the two magnetic elements 60 and 60 as far apart as possible with the objective optical system 31 and the illumination light emitting units 23 and 23 interposed therebetween, the analysis accuracy of the angle (ψ) of the insertion unit 12 is improved. Can do.

  The calculation result of the position and orientation of the distal end portion of the insertion portion 12 is sent from the controller 51 to the computer 53. The computer 53 displays the position and orientation of the distal end portion of the insertion portion 12 on the three-dimensional image data in real time. As a result, the surgeon can accurately insert the insertion portion 12 along the intended route by referring to the display screen. Since not only the position and extension direction of the distal end portion of the insertion portion 12 but also the angle around the axis can be detected, for example, when the bending portion 13 is bent, it can be reliably bent in the intended direction. Thereby, the insertion part 12 can be reliably and easily reached to the target point without damaging the brain tissue.

  Even if two magnetic elements 60 and 60 are further accommodated in the distal end portion of the insertion portion 12 in addition to the illumination light emitting portion 23, the objective optical system 31, and the channel tube 41, these elements 23, 31, 41, By devising the layout of 60, the increase in diameter of the insertion portion 12 can be suppressed. Therefore, the burden on the patient can be reduced.

  During maintenance of the endoscope 10, the proximal end portion of the magnetic signal line 65 is cut from the connector 67 and the cap 15 is removed from the distal end of the insertion portion 12. Then, the tip surface of the magnetic element 60 is exposed. The magnetic element 60 is pulled out from the distal end side of the insertion portion 12. Thereby, the magnetic element 60 can be easily separated from the endoscope 10.

The present invention is not limited to the above embodiment, and various modes can be adopted within the scope of the gist.
For example, the coil 63 constituting the magnetic element 60 of the endoscope 10 is energized to generate a magnetic field from the magnetic element 60, and the coil group device 52 is replaced with a magnetic field source as a magnetic field detector. The magnetic field from the magnetic element may be detected by the coil.
The number of magnetic elements 60 provided in the insertion portion 12 may be three or more.
The magnetic element 60 is not limited to a coil sensor including the magnetic coil 63, and may be a Hall sensor or a magnetic flux gate sensor.
The two magnetic elements 60 may be non-coaxial and non-parallel.
It is not always necessary that the illumination light emitting units 23 and 23 and the objective optical system 31 are sandwiched between the two magnetic elements 60 and 60. Of the illumination light emitting units 23 and 23 and the objective optical system 31, It is sufficient that at least one is sandwiched. For example, the objective optical system 31 may be sandwiched between the two magnetic elements 60 and 60, and the illumination light emitting units 23 and 23 may be disposed outside the two magnetic elements 60 and 60.

  As an image transmission system, an imaging element such as a CCD is provided at the distal end rigid portion 14, and an electric signal line is accommodated in the insertion portion 12 and the main body portion 11 instead of the optical fiber 32, and an optical image incident on the objective optical system 31 is received. You may decide to convert and transmit to an electrical signal with an image pick-up element. In this case, the objective optical system 31 and the imaging device constitute an objective part of the image transmission system and constitute one of the embedded objects at the distal end portion of the insertion part 12. The image sensor has a relatively large diameter. Therefore, in order to avoid an increase in the outer diameter of the insertion portion 12, the channel tube 41 is made smaller in diameter, and as a result, the imaging element and thus the objective portion may be larger in diameter than the channel tube 41 and become the maximum embedded object. In that case, at the distal end of the insertion portion 12, an objective portion (maximum embedded object) composed of the objective optical system 31 and the imaging element is arranged eccentric to one side with respect to the axial center of the insertion portion 12, and the two magnetic elements 60, 60 are arranged. Then, the illumination light emitting part 23 and the channel tube 41 which are small embedded objects are arranged in the circumferential direction of the half-circumferential part opposite to the eccentric side of the objective part (maximum embedded object) composed of the objective optical system 31 and the imaging element. And at least one of the small buried objects 23 and 41 is disposed between the two magnetic elements 60 and 60.

DESCRIPTION OF SYMBOLS S Endoscope system 10 Endoscope 11 Main-body part 12 Insertion part 13 Bending part 14 Hard end part (tip part of insertion part)
15 End cap 16 Bending operation part 17 Holder 17a Channel tube accommodation hole 17b Illumination light emission part accommodation hole 17c Objective optical system accommodation hole 17d Magnetic element accommodation hole 19 Cable 20 Light source 21 Plug 22 Light guide (illumination light transmission means)
23 Illumination light exit (small buried object)
29 Light cable 31 Objective optical system (object, small buried object)
30 Image transmission system 32 Image guide 33 Eyepiece 40 Forceps port 41 Channel tube (maximum embedded object)
50 detection means 51 controller (analysis means)
52 Magnetic Field Source 53 Computer 60 Magnetic Element 63 Magnetic Field Coil 64 Housing 65 Magnetic Signal Line 66 Guide Tube 67 Magnetic Detection Connector 69 Magnetic Detection Cable

Claims (4)

It has a flexible insertion portion extending in a strip shape, and the distal end portion of the channel tube, the objective portion of the image transmission system, and the illumination light emitting portion are embedded as an embedded object at the distal end of the insertion portion, and at the distal end of the insertion portion The occupied area of one (hereinafter referred to as “maximum embedded object”) of the tip of the channel tube and the objective part is larger than any embedded object (hereinafter referred to as “small embedded object”) other than the maximum embedded object. In an endoscope,
Two magnetic elements for detecting the position and orientation of the distal end of the insertion part by detecting or generating a magnetic field are provided non-coaxially at the distal end of the insertion part, and the cross-sectional area of each magnetic element is smaller than the occupied area. The maximum embedded object is arranged eccentric to one side with respect to the axis of the insertion part at the tip of the insertion part, and the two magnetic elements and the small embedded object are arranged on the eccentric side of the maximum embedded object. The endoscope is arranged side by side in the circumferential direction of the half-circumferential portion on the opposite side, and at least one of the small embedded objects is sandwiched between the two magnetic elements.   2. The endoscope according to claim 1, wherein the two magnetic elements are spaced apart from each other by 30 ° or more and less than 180 ° around the axis of the insertion portion in the circumferential direction of the insertion portion.   The endoscope according to claim 1 or 2, wherein an outer diameter of the maximum embedded object is not less than one half of an outer diameter of the insertion portion. It has a flexible insertion portion extending in a strip shape, and the distal end portion of the channel tube, the objective portion of the image transmission system, and the illumination light emitting portion are embedded as an embedded object at the distal end of the insertion portion, and at the distal end of the insertion portion The occupied area of one (hereinafter referred to as “maximum embedded object”) of the tip of the channel tube and the objective part is larger than any embedded object (hereinafter referred to as “small embedded object”) other than the maximum embedded object. An endoscope,
Detection means for detecting the position and orientation of the tip of the insertion part by generating or detecting a magnetic field;
Two magnetic elements connected to the detection means for detecting or generating a magnetic field are provided non-coaxially at the distal end of the insertion part, and the cross-sectional area of each magnetic element is smaller than the occupied area, and the insertion part The maximum embedded object is arranged eccentric to one side with respect to the axis of the insertion portion at the tip of the insertion part, and the two magnetic elements and the small embedded object are opposite to the eccentric side of the maximum embedded object. An endoscope system, wherein the endoscope system is arranged side by side in a circumferential direction of a half circumference portion, and at least one of the small embedded objects is sandwiched between the two magnetic elements.

Images