JP2011182999A - Intraocular lens injection instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intraocular lens injection instrument capable of suitably positioning an intraocular lens without taking time or labor when sending the intraocular lens into an eye and opening it by using the intraocular lens injection instrument. <P>SOLUTION: The intraocular lens injection instrument includes: an injection tubular part having a path wherein the space that an intraocular lens passes through is gradually smaller as approaching the front end for folding the intraocular lens; a lens holding part for mounting the intraocular lens on the proximal end of the injection tubular part; and a plunger provided so as to be moved forward and backward in an axial direction inside the tube of an injection instrument body for pushing the intraocular lens out of the injection tubular part. In the intraocular lens injection instrument, a gap that a rear support part can pass through along the periphery of the front end is formed between the front end of the plunger and the front end opening of the injection tubular part in order to release the rear support part of the intraocular lens which behaves on the basis of the opening operation of the intraocular lens sent from the front end of the injection tubular part along the periphery of the front end of the plunger. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an intraocular lens insertion device for inserting an intraocular lens into the eye.

  Conventionally, it is composed of a soft optical part that can be bent after the lens is extracted as one of the surgical methods for cataract and a support part called a loop for fixing and holding the optical part in the eye. A method of inserting an intraocular lens is generally used.

  An intraocular lens insertion device called an injector is used to insert a foldable intraocular lens. In the injector, the tip of the insertion part of the intraocular lens is tapered, and the intraocular lens installed inside is pushed toward the tip of the insertion part at the tip of the push rod called the plunger, and its inner wall shape The intraocular lens is bent and made smaller in accordance with the above. In addition, by forming the tip of the insertion portion of the injector as small as possible so that the plunger and the intraocular lens can pass, the incision provided in the patient's eye can be reduced in diameter, reducing the burden on the patient. At the same time, the occurrence of after-effects such as postoperative astigmatism can be suppressed (see, for example, Patent Document 1).

JP 2006-333924 A

  However, as described above, in the conventional intraocular lens insertion device, in order to make the incision provided in the patient's eye as small as possible, the support located on the rear side of the intraocular lens is made small in order to make the tip of the insertion portion of the injector small. The part is easily sandwiched between the plunger and the insertion part opening. For this reason, if the rear support part is left in the insertion part with the optical part pushed out into the eye first, the rear side sandwiched between the distal end part of the plunger and the insertion part The optical unit may be opened using the support 42b as a support shaft. When the optical part is opened with the rear support part as a support shaft in this way, the optical part is inclined (inclined) in the eye, so the surgeon must correct the optical part to be in the correct position. It takes time and effort. On the other hand, it is a burden for the patient to lengthen the operation time.

  In the present invention, in view of the above-described problems of the prior art, when an intraocular lens is delivered into the eye and opened using an intraocular lens insertion tool, the intraocular lens can be suitably positioned without taking time and effort. It is an object of the present invention to provide an intraocular lens insertion device that can be used.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) In an intraocular lens insertion device for inserting a deformable intraocular lens having an optical part and a pair of loop-shaped support parts for supporting the optical part in the eye, An insertion cylinder part to be inserted into a provided incision, the insertion cylinder part having a passage in which a space through which the intraocular lens passes becomes narrower toward the tip for folding the intraocular lens, and the insertion cylinder part A lens holding portion for placing the intraocular lens on the proximal end of the insertion tube, and a plunger provided so as to be movable back and forth in the axial direction within the cylinder of the insertion instrument body in order to push out the intraocular lens from the insertion tube portion. In order to release the support part at the rear of the intraocular lens that behaves based on the opening operation of the intraocular lens delivered from the distal end of the insertion tube part along the periphery of the plunger tip part, The tip of the plunger and the A gap is formed between the insertion tube portion and the distal end opening so that the rear support portion can pass along the periphery of the distal end portion.
(2) In the intraocular lens insertion device according to (1), the gap is formed in the distal end portion in order to separate a predetermined range of the outer periphery of the distal end portion of the insertion tube portion from the inner wall of the distal end opening of the insertion tube portion. The predetermined range of the outer periphery is formed as a curved surface, a slope, or a concave surface.
(3) In the intraocular lens insertion device according to (2), the predetermined range of the outer periphery is any one of an outer periphery range extending from the upper surface to the side surface or from the lower surface to the side surface of the plunger tip.

  According to the present invention, when an intraocular lens is delivered into the eye and opened using an intraocular lens insertion device, the intraocular lens can be suitably positioned without taking time and effort.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of an intraocular lens 40, FIG. 1A is a front view of the intraocular lens 40, and FIG. 1B is a side view of the intraocular lens 40. FIG. Here, the support part 42 (the front support part 42a and the rear support part 42b with respect to the pushing direction) is formed with a thin loop shape (C-shaped, J-shaped) with the optical part 41 and the distal end being a free end. ) Are prepared separately, and thereafter, a three-piece intraocular lens obtained by integrating them will be described as an example.

  The optical unit 41 has a predetermined refractive power, and has a side surface 41a on which the push-out means 30 abuts when pushed out from an intraocular lens insertion device 1 to be described later (hereinafter referred to as an edge) 41a, and on the corneal side in the eye. A front surface 41b positioned and a rear surface 41c positioned on the retina side are provided. The optical unit 41 is formed of a material conventionally used for a flexible intraocular lens that can be bent, such as a simple substance such as HEMA (hydroxyethyl methacrylate) or a composite material of acrylic ester and methacrylic ester. Moreover, the support part 42 should just be formed from the material conventionally used as a support part of an intraocular lens, for example, is PMMA (polymethylmethacrylate) etc.

  FIG. 2 is a schematic external view showing the external appearance of the intraocular lens insertion device 1 used in the present embodiment. FIG. 2A shows the intraocular lens insertion device 1 as viewed from above, and FIG. 2B shows the state as viewed from the side. The intraocular lens insertion device 1 includes an insertion unit for inserting an intraocular lens from an incision formed in the eyeball in order from the side to be inserted into the eyeball, and a placement unit for installing the intraocular lens 40 is provided. A lens holding part 10 (hereinafter referred to as a cartridge) for holding the intraocular lens inside, and a cylindrical part (insertion instrument main body, handpiece) 20 which is an insertion instrument main body with the cartridge 10 attached to the tip (placed at the tip). And an extruding means (plunger) 30 for inserting the inside of the cartridge 10 and the cylindrical portion 20 and for extruding the intraocular lens 40 from the front end of the cartridge 10 attached to the cylindrical portion 20.

  Here, FIG. 3 is a schematic view of the external configuration of the cylindrical portion 20 excluding the cartridge 10, and FIG. 4 is an explanatory diagram of the internal configuration of the cylindrical portion 20 in a state where the cartridge 10 is mounted. A mounting portion 21 for attaching and detaching the cartridge 10 is provided at the tip of the cylindrical portion 20. The mounting portion 21 has a shape in which the distal end of the cylindrical portion 20 is substantially halved. A convex portion 22 is provided at the distal end, and a concave portion 23 is provided at the proximal end, and is symmetrical with respect to the pushing means 30 that passes through the center of the cylindrical portion 20 Each is formed. Further, the convex portion 22 is located slightly above the central axis of the cylindrical portion 20, and the distance between the convex portions 22 provided on the left and right is slightly narrower (shorter) than the inner diameter of the cylindrical portion 20. . Such a shape of the convex portion 22 has a snap-in structure that locks the mounted cartridge 10 so that the cartridge 10 is not easily detached from the cylindrical portion 20.

  The cartridge 10 is integrally formed with an insertion portion (insertion cylinder) 11 having a tapered shape having a region in which the inner diameter gradually decreases (thinner) toward the tip, and a placement portion 12 on which the intraocular lens 40 is installed. Is formed. The cartridge 10 is entirely made of synthetic resin and is a disposable type that is discarded after one use. The insertion portion 11 has a hollow cylindrical shape, and the folded intraocular lens 40 is sent out from the insertion portion distal end 11a formed in a substantially elliptical opening through the hollow portion. In the present embodiment, the valley-fold type cartridge 10 in which the front surface 41b of the optical unit 41 is valley-folded in the insertion unit 11 is used. Further, since the distal end 11a of the insertion portion 11 pushes the intraocular lens through a small incision, the inner diameter of the distal end 11a is small enough to be substantially equal to the outer diameter of the distal end portion 34 described later when viewed from the pushing direction. Suppose that it is formed.

  Inside the hollow cylindrical portion 20, an extruding means 30 is inserted so as to be able to advance and retreat in the axial direction through a passage connecting from the cylindrical portion 20 to the tip of the cartridge 10 (insertion portion 11). The push-out means 30 is connected to the distal end portion 34 having a side surface 34b and an abutting surface 34a in contact with the optical portion 41 (edge 41a), a pressing portion 33 pressed by the user, and the pressing portion 33. And a push bar 31 connecting the tip 34 and the shaft base 32.

  Here, the shape of the tip end portion 34 will be described in detail. FIG. 5 is an explanatory diagram of a positional relationship when viewed from the front in a cross section perpendicular to the extrusion direction in a state where the distal end portion 34 is positioned in the vicinity of the distal end 11 a of the insertion portion 11. FIG. 5A shows the positional relationship of the support part 42b when the optical part 41 is folded in the insertion part 11, and FIG. 5B shows the support when the optical part 41 is opened in the eye. The positional relationship of the part 42b is shown. FIG. 6 is an enlarged view of the distal end portion 34 when viewed from the side.

  Since the distal end portion 34 serves to send the intraocular lens 40 from the insertion portion 11 to the outside, the distal end portion 34 has a size (diameter) that can be inserted through the insertion portion 11 and the internal passage of the cartridge 10, and the contact surface 34 a is the optical portion 41. It is formed in such a size that it can sufficiently contact the edge 41a. Further, the distal end portion 34 is formed in a shape such that a predetermined region (lower surface) of the outer peripheral shape (side surface 34b) is along the inner wall surface w, and the length in the pushing direction is rubbed against the inner wall surface w. It is formed with a length that can move forward. As a result, the distal end portion 34 (lower surface) is moved without a gap with respect to the inner wall surface w, so that the distal end portion 34 bites into the optical portion 41 or the distal end portion 34 rides on the optical portion 41 and damages the optical portion 41. Is suppressed. It should be noted that the optical axis 41 of the distal end portion 34 can be further increased by forming the extrusion shaft of the extrusion means 30 so as to be slightly tilted downward so that the lower surface of the distal end portion 34 is pressed against the bottom surface of the inner wall surface w. You may make it suppress climbing up.

  Further, in the present embodiment, the shape of the distal end portion 34 is an outer peripheral range in which the rear support portion 42b is moved when the folded optical portion 41 is opened when viewed in a cross section perpendicular to the extrusion direction. Are formed in a predetermined curved surface shape (curved surface) R. In the curved surface R, the difference Δd between the distance d1 from the axis O to the curved surface R of the pushing means 30 and the distance d2 from the axis O to the inner wall surface w of the insertion portion 11 is sufficiently larger than the diameter Δd2 of the support portion 42b. It is formed to be large (d1 <d2), and the support portion 42b can pass along the outer periphery (side surface) of the tip portion 34 between the outer periphery of the tip portion 34 and the tip 11a (near the opening) of the insertion portion 11. A void p is formed. With such a configuration, as shown in FIG. 5A, the rear support portion 42b positioned above the tip portion 34 in the vicinity of the tip 11a has a gap with the behavior (opening) of the optical portion 41 thereafter. As shown in FIG. 5B, it passes through p and can move to the side surface side of the tip portion 34.

  By the way, since the optical part 41 bent in the insertion part 11 is pushed out from a smaller diameter as it moves to the front end side of the tapered insertion part 11, it is strongly pushed by the extrusion means 30. However, if the optical part 41 is pressed strongly when the bending is insufficient, the soft optical part 41 is deformed and the tip part 34 rides on the optical part 41, so that a part of the optical part 41 is part of the tip part 34. May sink into a slight gap generated between the side surface 34b (lower surface) of the inner wall surface and the inner wall surface w of the insertion portion 11. The optical unit 41 is further slid into the gap when the optical unit 41 is further pushed by the push-out means 30 in a state where the optical unit 41 has entered the gap. If further extrusion is performed in such a state, the optical unit 41 may be damaged. Further, if the distal end portion 34 rides on the optical portion 41, the distal end portion 34 may not be properly brought into contact with the edge 41a, and the optical portion 41 may not be pushed out.

  Therefore, in the present embodiment, a range in which the optical unit 41 may sink is formed on the rough surface RF on the side surface 34b (lower surface) of the distal end portion 34 (see FIGS. 5 and 6). In this way, even if the tip end portion 34 tries to ride on the optical portion 41 in the extrusion operation, the advancement is prevented by the frictional force due to the rough surface RF, and the submergence of the optical portion 41 is suppressed. Here, the maximum height Ry (JIS B 0601 1994) of the surface roughness of the rough surface RF is larger than Ry = 6.3 μm, and more preferably Ry = 12.5 μm to 100 μm. In addition, when the value of the rough surface Ry is Ry = 6.3 μm or less, a sufficient frictional force cannot be obtained, and it is difficult to suppress the penetration of the optical unit 11. On the other hand, if Ry is larger than 100 μm, the diameter of the tip 11a becomes large. The maximum height Ry of the surface roughness is extracted from the roughness curve obtained by measuring the unevenness of the surface state by the reference length of the average line, and the maximum value (mountain) of this extraction point The distance from the minimum value (valley) is measured in the direction of the vertical magnification of the roughness curve, and this value is expressed in micrometers.

  Here, a method for forming the rough surface RF will be described. First, the shape of the extrusion means 30 having a rough surface is formed by grinding the bulk material formed in a predetermined shape with a blade having a sharp tip. Next, except for the range where the rough surface RF is formed on the tip portion 34, a smooth surface state is formed by well-known polishing. Alternatively, once the entire surface of the extruding means 30 is made smooth by polishing, the range in which the rough surface RF is formed may be cut out with a blade or a wrinkle.

  Here, although the rough surface RF is formed on the lower surface of the side surface 34b, the present invention is not limited to this. If the rough surface RF is formed in a range where the optical part 41 is likely to sink into the gap between the tip part 34 and the inner wall surface w in accordance with the internal shape of the cartridge 10 or the shape of the tip part 34, etc. good. That is, the rough surface RF may be formed not only on the upper portion, the upper portion and the lower portion of the side surface 34b, and on the entire circumference, but also on the entire extrusion means 30 excluding the contact portion 34a. Here, the entire lower surface of the side surface 34b is formed on the rough surface RF, but the rough surface RF may be formed at least on the tip side (the contact surface 34a side) of the lower surface of the side surface 34b. This prevents a part of the optical unit 41 from proceeding to the gap.

  Next, the injection | pouring operation | movement of the intraocular lens 40 using the intraocular lens insertion instrument 1 provided with the above structures is demonstrated. An operator (user) places the intraocular lens 40 on the cartridge 10 using a lever or the like. Next, in order to mount the cartridge 10 on which the intraocular lens 40 is placed on the cylindrical portion 20, the push rod 31 is pulled out to the proximal end side of the cylindrical portion 20, and the cartridge 10 is inserted into the concave portion 23 provided in the mounting portion 21. And the distal end 11a of the insertion portion 11 is inserted into the patient's eye from which the crystalline lens has been removed. From this state, the pressing portion 33 is pushed, and the entire pushing means 30 (the tip 34, etc.) is moved forward.

  Here, the extrusion operation of the intraocular lens 40 will be described. FIG. 7 is a schematic cross-sectional view of the inside of the cartridge 10 as viewed from the side. When the pressing portion 33 is pushed in, the contact surface 34a comes into contact with the optical portion 41 as shown in FIG. When the pressing portion 33 is further pushed, the intraocular lens 40 enters the insertion portion 11. At this time, since the opening diameter of the insertion portion 11 is gradually narrowed, the optical portion 41 is bent along the inner wall surface w of the insertion portion 11 so that the front surface 41b is folded (rounded). . At this time, the tip 34 is advanced while rubbing with the lower surface of the side surface 34b in contact with the inner wall surface w. On the other hand, the support part 42b on the rear side is positioned on the upper side in the insertion part 11 as the optical part 41 is bent.

  Further, as the optical part 41 is pushed, the opening diameter of the insertion part 11 becomes narrower, so that the force pushing the pushing means 30 is gradually increased. At this time, there is a case where a part of the optical unit 41 tends to sink between the lower surface of the distal end portion 34 and the inner wall surface w of the insertion portion 11. However, in the present embodiment, it is possible to suppress the progress of the optical unit 41 that is about to sink due to the frictional force caused by the rough surface RF formed on the lower surface of the tip end portion 34. As a result, even if the optical unit 41 is strongly pressed by the pushing means 30 in the insertion unit 11, the optical unit 41 can be prevented from entering below the distal end portion 34, so that the optical unit 41 is damaged. It is suppressed. Moreover, since the front-end | tip part 34 is suppressed from climbing on the optical part 41, the optical part 41 whole can be extruded now suitably.

  When the distal end portion 34 moves to the vicinity of the distal end 11a of the insertion portion 11 as described above, the rear support portion 42b is bent by the optical portion 41 as shown in FIG. It will be located in the upper space formed by. Further, when the push-out means 30 is further pushed, as shown in FIG. 7C, the optical part 41 is first sent out from the tip 11a into the eye, and the rear support part 42b is inserted into the insertion part 11. It will be left in the state. At this time, as shown in FIG. 5B, the support part 42 b can escape from the upper side of the tip part 34 to the side through the gap p as the optical part 41 is opened. Thereby, the influence of the pinching by the support part 42b when the optical part 41 is opened is avoided, and the optical part 41 is suitably opened in the eye. Thereafter, when the support part 42b is pushed into the eye, its shape is restored in the eye, and is arranged along the sac by the stress applied from within the eye. Thereby, the optical part 41 is suitably held in the eye by the support part 42 (42a, 42b).

  As described above, the rear support portion 42b can move within the tip 11a along the outer periphery of the tip portion 34 in a state where the tip portion 34 of the pushing means 30 is positioned in the vicinity of the tip 11a of the insertion portion 11. By providing the gap p, the opening operation of the intraocular lens can be easily stabilized and can be suitably positioned within the eye.

  The present invention is not limited to the above configuration. For example, the shape of the tip 34 for forming the gap p is not only a curved surface, but also a flat surface formed by notches as shown in FIG. 5C, or as shown in FIG. Alternatively, it may be formed by a concave surface. In addition to this, the shape of the distal end portion 34 is a shape that forms a gap p for movably positioning the support portion 42b with the opening operation of the optical portion 41 in a state where the distal end portion 34 is in the vicinity of the distal end 11a. I just need it.

  Also, in order to avoid the effect of pinching by the support portion 42b and to open the intraocular lens 41 more suitably in the eye, the side surface 34b (upper surface) of the distal end portion 34 has a slope SL as shown in FIG. It is convenient if it is formed. The inclined surface SL is formed in such an inclination that the sectional area gradually decreases from the contact surface 34a toward the extrusion rod 31 when viewed in a cross section perpendicular to the extrusion direction. In this way, as the tip end portion 34 is pushed out from the state of being positioned near the tip end 11a, the gap p where the support portion 42a is movably positioned is formed wider. Thereby, when the support part 42a is pushed out from the insertion part 11, it becomes easier to return to an original state. Therefore, the influence on the optical part 41 due to the support part 42a remaining in the insertion part 11 can be further reduced.

  In the above description, the rough surface RF of the tip end portion 34 is formed by roughening the surface state by polishing with a blade or scissors, but there are various rough surfaces as shown in the rough surface transformation pattern of FIG. Any shape can be used. In FIG. 8, the left side is a bottom view of the distal end portion 34 viewed from the lower surface, and the right side is a side view of the distal end portion 34. For example, as shown to Fig.8 (a), rough surface RF2 by the convex part or recessed part formed in the shape of a line extended in the direction orthogonal to an extrusion direction may be formed. In this case, the rough surface RF2 can be formed by cutting or molding. It should be noted that the line-shaped convex portion or concave portion may be formed at least near the tip of the tip portion 34. Further, the rough surface RF2 may be formed by alternately repeating line-shaped convex portions and concave portions.

  Further, as shown in FIG. 8B, the rough surface RF3 may be formed by a combination of unevenness by a plurality of dots. Such a rough surface RF3 can be formed by molding. Also in this case, the rough surface RF3 may be formed at a position where there is a high possibility that the optical unit 41 will be submerged at least near the tip. Note that the maximum height Ry of the surface roughness of the rough surface RF2 and the rough surface RF3 shown in FIGS. 8A and 8B is larger than Ry = 6.3 μm, and preferably Ry = 50 μm to 200 μm.

  In the above description, the intraocular lens insertion instrument in which the intraocular lens 10 is valley-folded has been described as an example. However, depending on the type of intraocular lens insertion instrument, the optical unit 41 may be folded in a mountain. There are also things. In this case, the bending position of the optical unit 41 is positioned on the upper side in the insertion unit 11, and the bending position is pushed out by the distal end portion 34. Therefore, in the state in which the intraocular lens 40 is bent, The support part 42b is located below the tip part 34. In such a case, a curved surface, a slope, or from the lower surface to the side surface of the tip portion 34 so as to form a gap p that allows the support portion 42b to escape between the lower side of the tip portion 34 and the side surface connected thereto. What is necessary is just to provide a concave surface. As described above, in this case, the rough surface RF is formed at least in the predetermined region (upper surface) of the side surface 34b of the tip 34, so that the optical portion 41 can be prevented from entering. The breakage and the riding of the distal end portion 34 onto the optical portion 41 are suppressed, and the intraocular lens 40 can be pushed out suitably.

  Furthermore, there is a case where the bending position of the optical unit 41 is positioned on the side surface (left side or right side) in the insertion unit 11. In this case, the rough surface RF may be formed at least on the left side or the right side of the side surface 34b of the tip 34 according to the bending position of the optical unit 41. For example, when the bending position of the optical part 41 is mountain-folded on the left side in the insertion part 11, the left side of the side surface 34 b of the tip part 34 may be formed on the rough surface 34. That is, the rough surface RF generates a predetermined frictional force in contact between the distal end portion 34 and the intraocular lens 40, so that a part of the optical unit 41 enters between the distal end portion 34 and the inner wall surface w. What is necessary is just to form in the outer peripheral shape predetermined area | region of the front-end | tip part 34 which suppresses.

It is explanatory drawing of a structure of an intraocular lens. It is the schematic external view which showed the external appearance of the intraocular lens insertion instrument. It is a typical view of the external appearance structure of the cylinder part except a cartridge. It is explanatory drawing of the internal structure of the cylinder part in the state in which the cartridge was mounted | worn. It is explanatory drawing of the positional relationship of a front-end | tip part and an insertion part when it sees from the front in a cross section perpendicular | vertical with respect to an extrusion direction. It is an enlarged view when the front-end | tip part is seen from the side surface. It is a schematic diagram of a cross section when the inside of the cartridge is viewed from the side. It is an example of the transformation pattern of a rough surface.

p Gap 1 Intraocular lens insertion instrument 10 Lens holder (cartridge)
DESCRIPTION OF SYMBOLS 11 Insertion part 11a Insertion part front end 30 Extrusion means (plunger)
34 Tip 40 Intraocular lens 41 Optical unit 42 Support unit

Claims (3)

In an intraocular lens insertion device for inserting a deformable intraocular lens having an optical part and a pair of loop-shaped support parts for supporting the optical part in the eye,
An insertion cylinder part inserted into an incision provided in an eyeball, the insertion cylinder part having a passage in which a space through which the intraocular lens passes becomes narrower toward the distal end in order to fold the intraocular lens, and the insertion A lens holding portion for placing the intraocular lens at the proximal end of the tube portion, and a plan provided so as to be movable back and forth in the axial direction within the tube of the insertion instrument body in order to push out the intraocular lens from the insertion tube portion And a jar,
The distal end of the plunger is used to release the rear support portion of the intraocular lens that moves based on the opening operation of the intraocular lens delivered from the distal end of the insertion tube portion along the periphery of the distal end portion of the plunger. An intraocular lens insertion device in which a gap through which the rear support portion can pass along the periphery of the distal end portion is formed between the distal end portion and the distal end opening of the insertion tube portion. 2. The intraocular lens insertion device according to claim 1, wherein the gap is formed on the outer periphery of the distal end portion in order to separate a predetermined range of the outer periphery of the distal end portion of the insertion tubular portion from the inner wall of the distal end opening of the insertion tubular portion. An intraocular lens insertion device, wherein the predetermined range is a curved surface, a slope, or a concave surface. 3. The intraocular lens insertion device according to claim 2, wherein the predetermined range of the outer periphery is any one of an outer peripheral range extending from the upper surface to the side surface or from the lower surface to the side surface of the plunger tip. Instruments.

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