WO2018207539A1 - Endoscope - Google Patents

Abstract

The present invention provides an endoscope capable of maintaining a favorable field of view during dusting in transurethral lithotripsy. The endoscope has a lighting system 101 and an imaging optical system 102 at the tip end and satisfies the following conditional expression (1): 0.1 ≤ (2 × LLI × fL / φL) / LO ≤ 0.9 (1) Where LLI represents the distance between the center OL and the center OIM, OL represents the center of the lighting system 101 closest to the imaging optical system 102, OIM represents the center of the imaging optical system 102, LO represents the observation distance to an object, fL represents the absolute value of the focal length of the lighting system 101, and φL represents the diameter of the light flux of the illumination light incident on the lighting system 101 from a light source.

Description

Endoscope

The present invention relates to an endoscope.

In recent years, in electronic endoscopes in the medical field, treatment of minimally invasive lesions using an endoscope has been performed with the improvement of treatment ability in addition to improvement of diagnosis ability. Therefore, electronic endoscopes in the medical field are required to have an observation system and an illumination system that can ensure a good field of view both during observation and during treatment. For example, the following are known as endoscopes that can easily guide the treatment tool and endoscopes that control contrast.

JP 2001-13422 A Japanese Patent No. 5636922

In recent years, transurethral lithotripsy (hereinafter referred to as “TUL” as appropriate) using an endoscope, for example, a soft ureteroscope, has attracted attention as a method for treating renal stones and ureteral stones.

In normal TUL, stones are crushed with a crushing means such as laser, and fragments are extracted outside the body with basket forceps. On the other hand, a technique called dusting has recently attracted attention. Dusting is a technique in which stones are pulverized with a laser or the like and discharged outside the body. In this procedure, debris can be removed from the body by perfusion, so stones can be easily discharged and left behind.

However, the field of view may deteriorate due to the scattering of the illumination light to the powdered calculus. For an endoscope used for TUL, it is necessary to design an optimal illumination system and observation system in consideration of this case.

In addition, the means for solving the above-described problems starting from Patent Documents 1 and 2 described above have not been publicly known.

The present invention has been made in view of the above, and an object of the present invention is to provide an endoscope capable of maintaining a good visual field when dusting in TUL.

In order to solve the above-described problems and achieve the object, an endoscope according to at least some embodiments of the present invention has an illumination optical system and an imaging optical system at the distal end, and the following conditions The expression (1) is satisfied.
0.1 ≦ (2 × L _LI × f _L / φ _L ) / L _O ≦ 0.9 (1)
here,
L _LI includes a center _{O L,} the distance between the center _{O IM,
OL} is the center of the illumination optical system closest to the imaging optical system,
O _IM, the center of the imaging optical system,
L _O is the observation distance of the object,
f _L is the absolute value of the focal length of the illumination optical system,
φ _L is the beam diameter of illumination light incident on the illumination optical system from the light source side,
It is.

The present invention has an effect of providing an endoscope that can maintain a good visual field during dusting in TUL.

(A) is a figure showing the tip composition which looked at the endoscope concerning an embodiment from the object side. (B) is a figure which shows the structure of the light-emitting body vicinity. (C) is sectional drawing which shows the front-end | tip structure of the endoscope which concerns on embodiment. (D) is another figure which shows the structure of the light-emitting body vicinity. (E) is another sectional view showing the tip configuration of the endoscope according to the embodiment. (A) is a figure which shows the structure and optical path of the light-emitting body vicinity of the endoscope which concerns on embodiment. (B) is a figure explaining the parameter of the endoscope concerning an embodiment. (C) is another figure which shows the structure of the light-emitting body vicinity of the endoscope which concerns on embodiment, and an optical path. (D) is another figure explaining the parameter of the endoscope concerning an embodiment. It is another sectional view showing the tip composition of the endoscope concerning an embodiment. (A) is a figure which shows the front-end | tip structure which looked at the endoscope which concerns on Example 1, 2 from the object side. FIG. 7B is a diagram illustrating a distal end configuration of the endoscope according to the third embodiment when viewed from the object side. (C) is a diagram illustrating a distal end configuration of the endoscope according to the fourth embodiment when viewed from the object side. (D) is a diagram showing a distal end configuration of the endoscope according to Examples 5, 6, and 7 when viewed from the object side.

Hereinafter, the endoscope according to the embodiment will be described in detail based on the drawings. In addition, this invention is not limited by this embodiment.

FIG. 1A is a diagram illustrating a distal end configuration of the endoscope 100 according to the embodiment as viewed from the object side. The endoscope 100 includes an illumination optical system 101 and an imaging optical system 102 at a distal end portion, and satisfies the following conditional expression (1).
0.1 ≦ (2 × L _LI × f _L / φ _L ) / L _O ≦ 0.9 (1)
here,
L _LI includes a center _{O L,} the distance between the center _{O IM,
OL} is the center of the illumination optical system 101 closest to the imaging optical system 102,
O _IM is the center of the imaging optical system 102,
L _O is the observation distance of the object OBJ (see FIGS. 1C and 1E),
f _L is the absolute value of the focal length f _L of the illumination optical system 101,
φ _L is the luminous flux diameter of the illumination light IL incident on the illumination optical system 101 from the light source side (the light emitter 105 side),
It is.

Here, the observation distance L _O to the object OBJ (FIGS. 1C and 1E) is preferably an “average distance”. The “average distance” is, for example, a distance when performing dusting in the above-described TUL when the object OBJ is a calculus.

Here, the illumination optical system 101 has a case where it has a positive refractive power and a case where it has a negative refractive power. FIG. 1B is a diagram showing a configuration in the vicinity of the light emitter 105 when the illumination optical system 101 has negative refractive power. The focal length _{f L} of the illumination optical system 101 is a negative value. phi _L is a beam diameter of the illumination light IL incident from the light source side (light emitter 105 side) to the illumination optical system 101. The light emitter 105 is, for example, a light emitting diode (LED), a glass fiber that guides illumination light from a light source (not shown), or the like.

Debris DST that is pulverized from the calculus (object OBJ) scatters the illumination light IL. In order to prevent the field of view from being deteriorated by the scattered light, it is desirable that the position where the illumination light IL illuminates the stone is separated from the imaging optical system 102 as much as possible. That is, the optical path of the strong light ones light intensity of the illumination light IL, the position crossing the optical axis AX _IM of the imaging optical system 102, it is desirable that away from the object side of the imaging optical system 102.

FIG. 2A is a diagram showing a configuration and an optical path in the vicinity of the light emitter 105 of the endoscope 100. FIG. 2B is a diagram for explaining parameters of the endoscope 100. FIG. 2C is another diagram showing the configuration and the optical path in the vicinity of the light emitter 105 of the endoscope 100. FIG. 2D is another diagram for explaining parameters of the endoscope 100.

FIGS. 2A and 2B show a configuration in the case where the illumination optical system 101 has a negative refractive power. FIGS. 2C and 2D are configurations when the illumination optical system 101 has a positive refractive power.

Conditional expression (1) will be described. Of the light emitted from the illuminator 105, attention is focused on the light beam that diverges to the outermost side among the light beams having the strongest emission angle of 0 °, that is, the light beam near the peripheral edge of the effective diameter of the illumination optical system 101. .

2B and 2D, the angle β diffused from the illumination optical system 101 satisfies the following expression (a).
tan β = 2f _L / φ _L (a)

Furthermore, the distance L from the front end of the imaging optical system 102 when this light beam crosses the optical axis AX _IM (see FIGS. 1C and 1E) of the imaging optical system 102 is expressed by the following equation ( b) is satisfied (see FIG. 3). The illumination light IL reaches a position separated from the imaging optical system 102 by about L _LI × tan β. The stone is then illuminated to produce scattered light.
Distance L = L _LI × tan β
= 2 × L _LI × fL / φ _L (b)

If the distance L is small, the field of view deteriorates due to scattered light during dusting. On the other hand, if the distance L is too large, the light distribution in the attention area (for example, calculus) will deteriorate.

Conditional expression (1) is a relational expression regarding the distance L and the distance L 2 _O. The light distribution of the illumination light IL and the distal end layout of the endoscope 100 are selected so as to exceed the lower limit value of the conditional expression (1). Thereby, the optical path of the strong illumination light IL can be directed to a position away from the imaging optical system 102. As a result, the visual field deterioration due to the scattering of the illumination light IL can be suppressed.

It can prevent that the light distribution characteristic of an observation area deteriorates by being less than the upper limit of conditional expression (1).

Also, according to a preferred aspect of the present embodiment, it is desirable that the endoscope has two or more illumination optical systems at the distal end, and that all the illumination optical systems satisfy the conditional expression (1). Thereby, a favorable visual field can be provided at the time of endoscopic treatment such as urinary calculus crushing, and the operability of the endoscope at the time of treatment can be improved.

Moreover, according to the preferable aspect of this embodiment, it is further desirable to satisfy the following conditional expression (2).
1 mm ≦ 2 × L _LI × fL / φ _L ≦ 20 mm (2)
here,
L _LI includes a center _{O L,} the distance between the center _{O IM,
OL} is the center of the illumination optical system closest to the imaging optical system,
O _IM is the center of the imaging optical system,
fL is the absolute value of the focal length of the illumination optical system,
φ _L is the beam diameter of illumination light incident on the illumination optical system from the light source side,
It is.
Thereby, a better visual field can be secured.

Further, according to a preferable aspect of the present embodiment, it is desirable that the distal end portion further has a channel, there is one illumination optical system, and the following conditional expression (3) is satisfied.
40 ° ≦ θ ≦ 90 ° (3)
here,
θ, when the center of the channel in the cross section of the tip was _{O CH,} a line segment connecting the center _{O CH} and the center _{O IM,} the angle between the line connecting the center _{O CH} and the center _{O L,}
It is.

To crush the calculus, insert and remove the channel shell crushing probe of the endoscope, and perform the crushing operation while grasping the distance from the calculus. At the time of dusting, the field of view of the endoscope becomes cloudy due to crushed stone fragments. Therefore, it is difficult to grasp the positional relationship between the crushing probe protruding from the channel and the calculus. On the other hand, by recognizing the shadow generated by the illumination light of the crushing probe projected onto the calculus even during dusting, it becomes easy to grasp the positional relationship between the calculus and the crushing probe.

Therefore, the shadow of the crushing probe projected on the calculus is important for grasping the positional relationship between the crushing probe and the calculus. In the present embodiment, the positional relationship among the illumination optical system, the imaging optical system, and the channel through which the crushing probe is inserted / removed is defined so as to satisfy the conditional expression (3).

Satisfying conditional expression (3) makes it easier to visually recognize the shadow of the crushing probe projected onto the calculus. Thereby, the sense of distance between the calculus and the crushing probe can be easily grasped, and the operability at the time of endoscopic treatment is improved.

When the lower limit value of conditional expression (3) is not reached, the shadow of the crushing probe is hidden behind the crushing probe itself, and the shadow cannot be recognized.

If the upper limit value of conditional expression (3) is exceeded, the shadow of the crushing probe will appear in the direction of the center of the endoscope field of interest, and the operability of the endoscope during treatment will be reduced.

Hereinafter, each example will be described.

Example 1
FIG. 4A is a diagram illustrating a distal end configuration of the endoscope 200 according to the first embodiment when viewed from the object side. The endoscope 200 has an illumination optical system 101a, an imaging optical system 102a, and a channel 103a at the distal end. The illumination optical system 101a has one plano-convex positive lens with the plane facing the object side.

Various data Lens radius of curvature R = -0.600 mm
L _O = 6.50 mm
f _L = 0.935 mm

(Example 2)
FIG. 4A is a diagram illustrating a distal end configuration of the endoscope 201 according to the second embodiment when viewed from the object side. Like the first embodiment, the endoscope 201 includes an illumination optical system 101a, an imaging optical system 102a, and a channel 103a at the distal end. The illumination optical system 101a has one plano-concave negative lens with a plane facing the object side.

Various data Lens radius of curvature R = 0.368 mm
L _O = 6.50 mm
f _L = 0.574 mm

(Example 3)
FIG. 4B is a diagram illustrating a distal end configuration of the endoscope 300 according to the third embodiment when viewed from the object side. The endoscope 300 has an illumination optical system 101b, an imaging optical system 102b, and a channel 103b at the distal end. The illumination optical system 101b has one plano-convex positive lens with the plane facing the object side.

Various data Lens curvature radius R = -0.475 mm
L _O = 4.70 mm
f _L = 0.535 mm

Example 4
FIG. 4C is a diagram illustrating a distal end configuration of the endoscope 400 according to the fourth embodiment when viewed from the object side. The endoscope 400 has an illumination optical system 101c, an imaging optical system 102c, and a channel 103c at the distal end. The illumination optical system 101c has one plano-convex positive lens with the plane facing the object side.

Various data Lens radius of curvature R = -0.600 mm
L _O = 4.45 mm
f _L = 0.935 mm

(Example 5)
FIG. 4D is a diagram illustrating a distal end configuration of the endoscope 500 according to the fifth embodiment when viewed from the object side. The endoscope 500 has two illumination optical systems 101d1 and 101d2, an imaging optical system 102d, and a channel 103d at the distal end. Each of the two illumination optical systems 101d1 and 101d2 has a plano-convex positive lens with the plane facing the object side.

Various data Lens radius of curvature R = -0.370 mm
L _O = 20.0 mm
f _L is 0.577 mm for both left and right illumination optical systems.

(Example 6)
FIG. 4D is a diagram illustrating a distal end configuration of the endoscope 501 according to the sixth embodiment when viewed from the object side. The endoscope 501 has two illumination optical systems 101d1, 101d2, an imaging optical system 102d, and a channel 103d at the distal end. Each of the two illumination optical systems 101d1 and 101d2 has one plano-convex positive lens with the plane facing the aspherical object side.

Various data Lens paraxial radius of curvature R = -0.358 mm
L _O = 20.0 mm
f _L is 0.558 mm for both left and right illumination optics

In addition, the aspherical shape of the illumination optical systems 101d1 and 101d2 of the present embodiment is a surface shape represented by the following expression when the optical axis AX _L is the X axis and the height from the optical axis AX _L is h. is there.

K = 0
A4 = 1.2,000E + 00
A6 = 1.2,000E + 01

Here, C is a paraxial curvature, K is a conical coefficient, and A4 and A6 are fourth-order and sixth-order aspheric coefficients, respectively. In the aspheric coefficient, “E−n” (n is an integer) indicates “10 ⁻ⁿ ”.

(Example 7)
FIG. 4D is a diagram illustrating a distal end configuration of the endoscope 502 according to the seventh embodiment when viewed from the object side. The endoscope 502 has two illumination optical systems 101d1, 101d2, an imaging optical system 102d, and a channel 103d at the distal end. Each of the two illumination optical systems 101d1 and 101d2 has one plano-concave negative lens having a plane facing the aspherical object side.

Various data Lens curvature radius R = 0.358 mm
L _O = 20.0 mm
f _L is 0.558 mm for both left and right illumination optical systems.

The values corresponding to the conditional expressions in the respective examples are shown below.

Conditional expression (1) (2 × L _LI × f _L / φ _L ) / L _O
Condition _{(2) 2 × L LI ×} f L / φ L
Conditional expression (3) θ

Example Conditional Expression (1) Conditional Expression (2) Conditional Expression (3)
1 0.806 5.24 58.7 °
2 0.494 3.21 58.7 °
3 0.359 1.69 45.0 °
4 0.596 2.65 38.7 °
5 0.107 2.13 37.3 ° (right side) 41.1 ° (left side)
6 0.103 2.06 37.3 ° (right side) 41.1 ° (left side)
7 0.103 2.06 37.3 ° (right side) 41.1 ° (left side)

The endoscope described above may satisfy a plurality of configurations at the same time. This is preferable for obtaining a good endoscope. Moreover, the combination of a preferable structure is arbitrary. For each conditional expression, only the upper limit value or lower limit value of the numerical range of the more limited conditional expression may be limited.

Although various embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and may be implemented by appropriately combining the configurations of these embodiments without departing from the spirit of the present invention. The form is also within the scope of the present invention.

The present invention is useful for an endoscope that provides a good visual field during an endoscopic procedure such as urinary calculus crushing and improves the operability of the endoscope during the procedure.

100, 200, 201, 300, 400, 500, 501, 502 Endoscope 101, 101a to 101d2 Illumination optical system 102 102a to 102d Imaging optical system 103, 103a to 103d Channels O _IM , O _CH , O _I center
IL illumination light 104 imaging unit 105 illuminant DST fragment OBJ object

Claims (4)

1. It has an illumination optical system and an imaging optical system at the tip,
   An endoscope satisfying the following conditional expression (1):
   0.1 ≦ (2 × L _LI × f _L / φ _L ) / L _O ≦ 0.9 (1)
   here,
   L _LI includes a center _{O L,} the distance between the center _{O IM,
   OL} is the center of the illumination optical system closest to the imaging optical system,
   O _IM is the center of the imaging optical system,
   L _O is the observation distance of the object,
   f _L is the absolute value of the focal length of the illumination optical system,
   φ _L is the beam diameter of illumination light incident on the illumination optical system from the light source side,
   It is.
2. The endoscope has two or more illumination optical systems at the distal end,
   The endoscope according to claim 1, wherein all the illumination optical systems satisfy the conditional expression (1).
3. Furthermore, the following conditional expression (2) is satisfied, The endoscope according to claim 1 or 2 characterized by things.
   1 mm ≦ 2 × L _LI × f _L / φ _L ≦ 20 mm (2)
   here,
   L _LI includes a center _{O L,} the distance between the center _{O IM,
   OL} is the center of the illumination optical system closest to the imaging optical system,
   O _IM, the center of the imaging optical system,
   f _L is the absolute value of the focal length of the illumination optical system,
   φ _L is the beam diameter of illumination light incident on the illumination optical system from the light source side,
   It is.
4. A channel at the tip,
   The illumination optical system is one,
   The endoscope according to claim 1, wherein the following conditional expression (3) is satisfied.
   40 ° ≦ θ ≦ 90 ° (3)
   here,
   θ, when the center of the channel in a cross section of the tip portion was O _CH, a line segment connecting the center O _CH and the center O _IM, the angle between the line connecting the center O _CH and the center O _L,
   It is.
   

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