JP5501648B2 - Open device - Google Patents

Description

  The present invention relates to an open device used to open upper and lower eyelids during ophthalmic surgery or when administering a drug into the eye, and a method for manufacturing the same.

  When performing intraocular surgery such as cataract surgery, retinal vitreous surgery, glaucoma surgery, or extraocular surgery such as pterygium resection, disinfect and drape the keratoconjunctiva and its surroundings, and then open the eyelid using a cleaver Take action in the same condition. In recent years, in developed countries, intravitreal local administration of angiogenesis inhibitors has been effective as a treatment method for age-related macular degeneration, the leading cause of premature blindness. is increasing. Vitreous injections of this angiogenesis inhibitor are carried out every month to every other month, and at this time as well, each time an open anesthesia is applied and an injection treatment is performed after opening the eyelid using an open eye device. Thus, recently, the use of eyelids has increased greatly.

  Conventionally, a metal opening device is mainly made of metal, and an example thereof is shown in FIG. 14 (see Patent Document 1).

  The eyelid opening device 60 shown in FIG. 14 has an eaves presser 62 comprising two curved plates that are respectively hooked on upper and lower eaves at both ends of an arm 64 formed by bending a metal wire having a spring property into a U shape. Are joined by brazing or the like, and the open state is maintained by the spring repulsive force of the arm 64.

  Each heel pressing portion 62 is formed in a U-shaped cross section having an inner insertion piece 62a inserted inside the heel and an outer pressing piece 62b for pressing the outer side of the heel so as not to lose the patient's own closing force. The arm 64 is made of a wire having a high flexural modulus.

  These openers can open the upper eyelid and the lower eyelid by the spring repulsive force of the arm 64 by hooking the eyelid presser portions 62 provided at both ends of the arm 64 to the upper eyelid and the lower eyelid.

However, as mentioned above, even though the number of scenes in which openers are used recently has increased, metal openers are expensive and cannot be made disposable, and must be sterilized. I had to use it many times.
Further, in the case of a metal opening device, the bending elastic modulus of the arm is apt to increase, and the portion that directly contacts the heel is a hard material. Therefore, in the case of a patient who cannot open a large opening, since the spring force is too strong, it is easy to feel pain, and troubles such as an increase in vitreous body pressure may be induced.

  Therefore, the present inventor has invented an eyelid opening device that can be disposable and eliminates the hassle of sterilization, while exhibiting supple elasticity and soft contact feeling, while having a type having an arm that exhibits a spring action. (See Patent Document 2).

Utility Model Registration No. 3105573 Japanese Patent Application No. 2008-293179

  By the way, in the structure made of resin, there are generally the following considerations.

One is about the strength of the resin structure.
Usually, the resin molding method includes a method of scraping a structure from a block-shaped resin material, a method of polymerizing and curing in a resin mold or mold, or a method of injection molding using a thermoplastic resin.

  Of these, the injection molding method using the thermoplastic resin is particularly suitable for mass production of a uniform product. Specifically, in this injection molding method, a resin having fluidity at a high temperature is poured into a molding die attached to an injection molding machine and cooled. Next, a resin structure, which is a molded product with a gate portion (hereinafter also referred to as a resin injection portion), a runner, and a spool, is taken out from the mold. Then, the gate portion is cut and removed.

  Usually, the gate portion, which is the entrance of the resin into the mold, is designed to be a position that does not interfere with the work in molding the molded product and is easily filled with the resin evenly. As shown in FIG. 15, when compared with an eye-opening device 60 having a line-symmetric U-shaped curved arm 64, the gate portion 65 is located outside the curved portion of the U-shaped curved shape, particularly at the curved-symmetrical portion. Designed.

  When the surgeon attaches the eyelider 60 to the eyes of a patient, when the loader 60 is strongly pinched with a finger and a load is applied in a direction to bring the upper and lower eyelid presser parts 62 closer to each other, the eyelid presser part 62 is temporarily provided. The distance between them is reduced, and compressive stress acts on the inside of the U-shaped curved shape, and tensile stress acts on the outside of the curved shape. If this tensile stress is applied excessively, the arm may be damaged. Furthermore, when the surgeon pinches the opener 60 with his / her finger, there is a risk that the surgeon may be overstressed by worrying about whether the arm is broken.

Another consideration is the function of the resin structure.
In the case of an opener, it is necessary to make the thickness of the arm 64 thicker than that made of metal in order to have a rebound resilience that has an opening force that does not lose the closing force. If the opener 60 is made of metal, it can be achieved with a diameter of around 1 mm. On the other hand, if the diameter of the arm exceeds 3 mm in order to give the opener an opening force, the surgical instrument will collide. This is not preferable because it may cause a sense of pressure on the surgical field.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an eyelid opening device that has an appropriate opening force, reduces stress applied to the operator, and can sufficiently perform the necessary function of opening the upper and lower eyelids, and a method for manufacturing the opening device. There is.

In the first aspect of the present invention, one arm made of a thermoplastic resin formed into a curved shape by injection molding so as to have a spring property, and an upper collar and a lower collar are respectively coupled to both ends of the arm. An opener having two hook holding parts to be hooked and maintained in an open state by a spring repulsive force of the arm, and bending load in a direction in which the bar holding parts are brought closer to the arm , The neutral surface of the arm as a boundary, the outer side of the curved shape and the side where tensile stress is generated is the outer side of the arm, and the inner side of the curved shape and the side where compressive stress is generated When the arm is inside, the resin injection part of the arm is provided in a part other than the part where the tensile stress generated when the load is applied in the direction in which the pressing parts are brought closer to each other. Characterize However, the neutral surface is a region in which tensile stress is applied by the bending moment and a compressive stress in a cross section in which a plane perpendicular to the longitudinal direction of the arm is cut when a bending moment is applied to the arm. A region is formed, but is a boundary surface between a region where tensile stress is applied and a region where compressive stress is applied, and is a surface where neither tensile stress nor compressive stress is applied.

  According to a second aspect of the present invention, in the invention described in the first aspect, the resin at the time of injection molding of the arm is formed on a portion other than the outermost arm which is the portion farthest from the neutral surface outside the arm. An injection portion is provided.

  According to a third aspect of the present invention, in the invention according to the second aspect, a resin injection portion for injection molding of the arm is provided inside the arm.

  According to a fourth aspect of the present invention, in the invention described in the third aspect, a resin injection part at the time of injection molding of the arm is provided on the innermost side of the arm, which is the part farthest from the neutral surface. Is provided.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the arm is curved in a U shape.

  According to a sixth aspect of the present invention, in the invention according to the fifth aspect, the shape of the arm cross section, which is a cross section cut along a plane perpendicular to the longitudinal direction of the arm, is substantially circular. To do.

  According to a seventh aspect of the present invention, in the invention according to the sixth aspect, in the cross section of the arm, a direction from the substantially circular center toward the outermost side of the arm is an x axis, and passes through the substantially circular center to the x axis. When the vertical direction is the y-axis and the tangent to the arm in this xy coordinate system is expressed by a function of y = ax + b (where a and b are constants), the inclination of the tangent to the arm on the outside of the arm The resin injection portion is provided in a portion where the absolute value does not exceed 1 or inside the arm.

  According to an eighth aspect of the present invention, in the invention according to the sixth aspect, the arm is curved in a line-symmetric shape, and the resin injection portion is provided on the innermost side of the arm at the symmetrical center portion of the arm. It is characterized by. However, the innermost side of the arm means a part farthest from the neutral surface on the inner side of the arm.

  According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the spring repulsive force that is generated when a load is applied in a direction in which the heel pressing portions are brought closer to each other is adjusted. An opening force adjusting portion is provided inside the arm.

  According to a tenth aspect of the present invention, in the invention according to the ninth aspect, the arm is bridged by the opening force adjusting portion.

  An eleventh aspect of the present invention is the invention described in the ninth aspect, wherein the opening force adjusting portion is provided in a direction from the portion where the tensile stress generated on the outer side of the arm is maximized toward the inner side of the arm. It is also a fold suppression region that is formed.

  According to a twelfth aspect of the present invention, in the invention described in the eleventh aspect, an arm cross-sectional shape perpendicular to the longitudinal direction of the arm is substantially circular, and perpendicular to the longitudinal direction of the arm. In such a cross-sectional shape of the arm, the distance from the outermost arm to the innermost arm of the arm cross-sectional shape including the point where the tensile stress generated on the outer side of the arm is maximum is maximized over the arm. However, the outermost arm means the part farthest from the neutral surface outside the arm, and the innermost arm means the part farthest from the neutral surface inside the arm.

  According to a thirteenth aspect of the present invention, in the invention described in the eleventh aspect, an arm cross-sectional shape perpendicular to the longitudinal direction of the arm is substantially circular, and perpendicular to the longitudinal direction of the arm. In such a cross-sectional shape of the arm, the cross-sectional area of the cross-sectional shape of the arm including a point at which the tensile stress generated outside the arm is maximum is maximized over the arm.

  According to a fourteenth aspect of the present invention, in the invention described in the twelfth aspect, the arm is formed in a U-shape and a line-symmetric shape, and is at least 4 mm in the longitudinal direction of the arm around the center of symmetry. The cross-sectional area of the arm cross section perpendicular to the longitudinal direction of the arm in the range of the range is larger than the cross-sectional area of the other portions.

  According to a fifteenth aspect of the present invention, in the invention described in the thirteenth aspect, in the cross-sectional area of the arm cross section perpendicular to the longitudinal direction of the arm, the cross-sectional area of the arm gradually increases from both ends of the arm. It is characterized by being formed large.

  According to a sixteenth aspect of the present invention, there is provided an arm made of a thermoplastic resin formed into a curved shape by injection molding so as to have a spring property, and an upper collar and a lower collar respectively coupled to both ends of the arm. Each having two hook holding parts to be hooked, and an opener configured to maintain an open state by a spring repulsive force of the arm, wherein at least the arm is formed by an injection molding method, Injection molding is performed by providing a resin injection portion of the arm in a portion other than a portion where the tensile stress generated when applying a load in a direction in which the presser foot portions approach each other is maximized. It is the manufacturing method of the opening device to do.

  According to a seventeenth aspect of the present invention, in the invention described in the sixteenth aspect, the injection molding is performed by providing a resin injection portion of the arm inside the arm. However, the inner side of the arm is the inner side of the arm when the bending load is applied in the direction in which the presser foot parts are brought closer to each other. The side where stress is generated. The neutral surface is a region in which a tensile force is applied by the bending moment and a compressive stress in a cross section in which a plane perpendicular to the longitudinal direction of the arm is cut when a bending moment is applied to the arm. A region is formed, but is a boundary surface between a region where tensile force is applied and a region where compressive stress is applied, and is a surface where neither tensile force nor compressive stress is applied.

  According to an eighteenth aspect of the present invention, in the invention according to the sixteenth or seventeenth aspect, the injection molding is curved and formed in a U-shape and a line-symmetric shape, with the arm centered on the center of symmetry. The arm of the portion in the range of at least 4 mm in the longitudinal direction is formed such that the cross-sectional area of the arm cross section perpendicular to the longitudinal direction of the arm is larger than the cross-sectional area of the other portion. The resin injecting portion is provided on the innermost side of the arm in the symmetrical central portion. However, the innermost side of the arm means a part farthest from the neutral surface on the inner side of the arm.

  According to a nineteenth aspect of the present invention, in the invention according to any one of the sixteenth to eighteenth aspects, the arm and the heel pressing portion are integrally formed by an injection molding method of a thermoplastic resin. It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the opening device which fully performs the required function of reducing the stress given to an operator and opening an upper and lower eyelid, and its manufacturing method, while having moderate opening force. .

The structure of the eyelid opening device of embodiment of this invention is shown, (a) is a perspective view, (b) is a top view, (c) is a side view, (d) is a front view, (e) is (d). It is an enlarged view of Ie part, (f) is arm sectional drawing of AA '. It is a figure which shows the use condition of the same opener. It is a top view which shows an example of the opening device which concerns on this embodiment. It is the schematic explaining the manufacturing process of an opener, (a) is a top view of a metal mold | die, (b) is a top view when a resin molding is extracted from a metal mold | die, (c) is a resin molding It is a top view after excising a gate part. It is explanatory drawing about generation | occurrence | production of a crease | fold by use of an opener, (a) is a top view of the opener schematically showing a load and a neutral surface, and (b) is a tensile stress and a compressive stress acting on an arm. FIG. 4C is an enlarged plan view of a portion B schematically showing (a), and (c) is a plan view of the eyelid opening device when the arm is broken. It is sectional drawing which shows an example of the opening device which concerns on this embodiment. It is the schematic explaining the manufacturing process of the eyelid opening device which concerns on this embodiment, (a) is a top view of a metal mold | die, (b) is a top view when a resin molding is extracted from a metal mold | die, (c). Is a plan view after cutting the gate portion of the resin molded product, and (d) is an enlarged plan view of a portion B when tensile stress is applied. The structure of the eyelid opening device which combined this embodiment is shown, (a) is a perspective view, (b) is a top view, (c) is a side view, (d) is a front view, (e) is (d). It is an enlarged view of Ie part. The structure of the opening device which combined this embodiment is shown, (f) is a schematic plane explanatory drawing which shows a mode that the gate part of a resin molding is cut in the manufacturing process of the conventional opening device, (g) is this It is a schematic plane explanatory drawing which shows a mode that the gate part of a resin molding is cut out in the manufacturing process of the eyelid opening device which concerns on embodiment. It is a schematic plane explanatory drawing which shows the mode of displacement of the bar clamp part at the time of applying a load in the direction in which the bar clamp parts of the opener according to this embodiment are brought close to each other, and (a) is an easily deformable region in the arm. FIG. 4B is a schematic plan explanatory diagram when the area is large, and FIG. 5B is a schematic plane explanatory diagram when the region where deformation is easy is small. It is a schematic plane explanatory drawing which shows the modification of the opening force adjustment part which concerns on this embodiment. It is a schematic plane explanatory drawing which shows the modification of the opening force adjustment part which concerns on this embodiment. The structure of the eyelid opening device of another embodiment of this invention is shown, (a) is a perspective view, (b) is a top view, (c) is a side view, (d) is a front view, (e) is (d It is an enlarged view of Ie part of). It is a top view which shows an example of the opening device of another embodiment of this invention. It is a figure which shows an example of the opening device of another embodiment of this invention, (e) is sectional drawing of an arm, (f) And (g) is a top view which shows an example of an opening device. It is a figure which shows the conventional opening device. The opener with the resin injection portion provided on the outermost side of the arm, (a) is a plan view and (b) is a cross-sectional view taken along line A-A ′. It is the schematic explaining the manufacturing process of the eyelid device in which the resin injection | pouring part is provided in an arm outermost side, (a) is a top view of a metal mold | die, (b) is the explanatory top view to which the gate part vicinity of the arm was expanded, (C) is an explanatory top view which shows a mode that the bending of an arm generate | occur | produces. It is explanatory drawing which shows a mode when a load is applied to the arm in the Example. It is a figure which shows the relationship between the compression load and compression displacement in a present Example and a comparative example. It is a schematic explanatory drawing which shows the opening device, runner, and spool which concern on this embodiment.

(Embodiment 1)
Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.
1A and 1B show a configuration of the eyelid opening device 10 of the embodiment, where FIG. 1A is a perspective view, FIG. 1B is a plan view, and FIG.
(D) is a front view, (e) is an enlarged view of Ie part of (d), (f) is an AA 'arm sectional view. Moreover, FIG. 2 is a figure which shows the use condition.

  As shown in FIGS. 1 and 2, the eyelid opening device 10 includes a wire-like arm 14 made of a thermoplastic resin that is curved by injection molding so as to have a spring property, and both ends 14 a of the arm 14. And two eyelid pressers 12 that are respectively coupled to the upper eyelid 102 and the lower eyelid 103 of the eye 101.

  In the opening device 10, at least the arm 14 is formed as a molded product of a thermoplastic resin, and the opening state is maintained by the spring repulsive force of the arm 14.

Here, the configuration of each part of the opening device 10 will be described.
First, the upper and lower eyelid holding portions 12 provided in the opening device 10 are formed of resin, metal, or the like. In the present embodiment, a case of resin is used.

The upper and lower heel presser portions 12 are configured by a U-shaped curved plate having an inner insertion piece 12a inserted inside the heel and an outer presser piece 12b that presses the outer side of the heel.
At this time, the length Lb in the direction along the edge of the outer pressing piece 12b may be set larger than the length La in the direction along the edge of the inner insertion piece 12a.

Further, as shown in FIG. 1 (e), the thickness of the curved plate constituting the heel pressing portion 12 is gradually increased from the U-shaped curved portion where the inner insertion piece 12a and the outer pressing piece 12b are connected toward both tip portions. It has changed to become thinner. That is, the dimensions t2 and t3 are smaller than the dimension t1 in the figure (t1> t2 = t3). In this case, for example, t1 = about 0.6 mm and t2 = t3 = about 0.4 mm. The allowable width of the dimension of t1 is preferably in the range of 0.5 to 0.7 mm, for example, and the allowable width of the dimension of t2 and t3 is preferably in the range of, for example, 0.3 to 0.5 mm. . If the minimum thickness portion is made too thin, it becomes easy to break, so it is necessary to secure a thickness that is unlikely to crack at least.
In addition, although it is preferable that the change of the thickness of the curved plate which comprises the collar holding part 12 is provided continuously, you may provide in steps.

  Further, the upper and lower heel pressing portions 12 having a U-shaped cross section are formed so as to open slightly by an angle θ (about 20 °) on the side opposite to the side where the arm 14 is located. In addition, the back portions (portions corresponding to the bottom of the U shape) of the upper and lower heel pressing portions 12 having a U-shaped cross section are curved in a concave shape with a curvature of a radius R.

  In this way, each eave presser portion 12 is configured by a U-shaped curved plate having an inner insertion piece 12a inserted inside the eaves 102 and 103 and an outer presser piece 12b holding the eaves 102 and 103 outside. Since the thickness of the bending plate is changed so that at least the distal end portion on the inner insertion piece 12a side is thinner than the U-shaped bending portion where the inner insertion piece 12a and the outer pressing piece 12b are connected, The patient's feeling of burden when inserting the inner insertion piece 12a into the inner side of the heel can be reduced while maintaining the strength of the heel pressing portion 12 that is made.

For example, in a conventional metal opening device, it is extremely difficult to change the thickness of the presser foot part, whether the presser foot part is formed of a metal plate or a wire rod. However, in the case of the resin opening device 10 as in the present embodiment, the heel presser 12 can be simply configured by adding a dimension setting corresponding to the thickness change to the mold during molding. The thickness change can be freely given to the curved plate. Therefore, by reducing the thickness of at least the distal end portion of the inner insertion piece 12a, it is possible to reduce the patient's burden when inserting the inner insertion piece 12a into the inner side of the heel. Moreover, although the thickness of the front-end | tip part of the inner side insertion piece 12a is made thin, since the thickness of the U-shaped curved part which is the base side is set thickly, the inner side insertion piece 1
The strength of the connecting portion between 2a and the outer pressing piece 12b can be kept sufficiently large, and durability against cracking and breakage can be imparted.

  Further, since the length in the direction along the edge of the collar of the outer pressing piece 12b is set larger than that of the inner insertion piece 12a, the inner insertion piece 12a can be smoothly inserted into the back side of the collars 102 and 103. As shown in FIG. 2, it is possible to cover many of the eyelashes 105 and the roots of the upper and lower eyelids 102 and 103 by the large outer presser piece 12b.

  For example, when a vitreous injection of an angiogenesis inhibitor is performed, a sterilized eyelid device is directly attached to the eye 101 that is not draped. As shown in FIG. 2, many eyelashes 105 that may be contaminated with bacteria or dirt and their roots can be covered in a wider range than before. Thereby, the risk of developing endophthalmitis can be reduced by inserting the injection needle touching the eyelashes 105 into the eye. In addition, since the size of the outer pressing piece 12b is increased, the upper and lower eyelids 102 and 103 can be pressed on a wide surface, so that the patient is less likely to complain of pain and an increase in vitreous pressure is induced. It becomes difficult.

  In particular, since the length of the outer presser piece 12b is set to 16 mm or more and the length of the inner insert piece 12a is set to 15 mm or less, the feeling of burden on the patient when the inner insert piece 12a is inserted into the back side of the collars 102 and 103 is reduced. However, a safe treatment can be performed by pressing the eyelashes 105 on the front side of the eyelids 102 and 103.

  In addition, as shown in FIG. 1 (d), by setting the dimension Wa in the direction of insertion into the inner side of the inner pressing piece 12a to be smaller than the dimension Wb in the same direction of the outer pressing piece 12b, The burden can be further reduced, and the operability at the time of attachment / detachment can be improved.

Next, the arm 14 that connects the heel presser portions 12 will be described in detail.
As shown in FIG. 3, it is preferable that the arm 14 be curved in a U-shape so as to have a spring property (FIG. 3A). Further, the arm 14 may have a line-symmetric shape with an axis passing between the two scissor presser portions 12 as a symmetric axis so that the upper and lower scissors can be uniformly pressed by the two scissor pressers 12. It is preferable (FIG. 3B).

  The shape of the arm 14 is only required to be curved so as to have a spring property. Although the entire arm is U-shaped, the U-shaped bottom portion is partially deformed to be bent into a substantially W-shape. Although it may be formed (FIG. 3C), it is also U-shaped, but by bending the bottom of the U-shaped part, at least one tip end of the arm 14 is curved so that it can be easily picked with a finger. The shape may be changed (FIG. 3D).

  In addition, the curved shape of the arm 14 in this embodiment should just be a curved shape which has a spring repulsive force, and the outer curve or the inner curve of the arm 14 may be a linear shape instead of a curved shape. Furthermore, as long as the arm 14 has a spring repulsion force as an opener, at least a part of the outer curve and the inner curve of the arm 14 may be a linear shape instead of the curved shape.

  Further, as shown in FIG. 1 (f) which is a cross section taken along the line AA ′ of FIG. 1 (b), the arm cross-sectional shape perpendicular to the longitudinal direction of the arm may be a circular shape, an elliptical shape, or a part thereof. A substantially circular shape such as a deformed shape may be used, or a polygonal shape or a rectangular shape may be used. However, from the viewpoint of ease of picking and bending of the arm 14 for the operator, the shape must be substantially circular. Is preferred.

  The arm 14 is made of a thermoplastic resin, for example, polymethyl methacrylate (hereinafter also referred to as PMMA). As other materials, polyolefins such as polyethylene and polypropylene, polysulfone, polyphenylsulfone, polyether polyetheretherketone, polycarbonate, and polyphenylsulfone can be used.

  At this time, it is preferable that the arm 14 and the heel pressing portion 12 are configured as an integrally molded product of resin. Since the whole is formed by integral molding of a thermoplastic resin, it can be easily mass-produced at low cost. Therefore, it is possible to use it disposable, and it is possible to meet a large amount of usage requirements without requiring sterilization.

  Further, in the case where the arm 14 and the heel presser 12 are configured as an integrally molded resin product, the possibility of breakage due to repeated fatigue of the resin is eliminated by using the opener 10 as a disposable type. It is possible to improve safety. In addition, since the portion that directly touches the heels 102 and 103 (the heel pressing portion 12) is made of a resin whose hardness is lower than that of the metal, a soft contact feeling can be given to the patient, and the patient's feeling of burden can be reduced. Can be reduced.

  In addition, when using the opening device 10 as a disposable type, it is optimal to use PMMA which can be injection-molded from a cost standpoint and a track record as a medical device.

Next, a method for manufacturing the eyelid opening device 10 in the present embodiment will be described.
In this manufacturing method, the case where the arm 14 and the heel presser 12 are configured as an integrally molded product of resin is described. However, the arm 14 and the heel presser 12 are configured as separate molded products. Also good.

  In the injection molding in the present embodiment, as shown in FIG. 4, fluidity is imparted at a high temperature in an opener molding die 16 (hereinafter also referred to as a die 16) attached to an injection molding machine (not shown). Inject a thermoplastic resin. The mold 16 is provided with a portion for injecting a resin, that is, a mold resin injection portion 17, and a thermoplastic resin is injected from this portion of the mold 16 and then cooled (FIG. 4A).

  Next, the pre-finishing opener 10a, which is a molded product, is taken out from the mold 16. At this time, the pre-finishing opening device 10a is provided with a resin injection portion 15 (hereinafter also referred to as a gate portion) having the same shape as the mold of the mold resin injection portion 17 (FIG. 4B). The gate portion 15 of the pre-finishing opening device 10a is cut and removed by a heated nipper to produce the opening device 10 (FIG. 4C).

The operation of the opening device 10 thus obtained will be described.
When the surgeon wears the eyelid opener 10 in the eyes of the patient, the load is applied in a direction in which the opener 10 is strongly pinched with a finger to bring the eyelid presser parts 12 closer to each other. Thereby, after narrowing the distance between the eyelid presser portions 12, the eyelid opening device 10 is attached to the eyes of the patient. When the finger is released from the eyelider 10 after wearing, the eyelider 10 is fixed to the eyes of the patient by the spring repulsive force due to the elasticity of the arm 14 itself.

As shown in FIG. 5, compressive stress and tensile stress are generated in the arm 14 while a load is applied in a direction in which the opener 10 is strongly pinched with a finger and the heel pressing portions 12 are brought closer to each other. Here, when a bending moment is applied to the arm 14 by applying the load, a region in which a tensile stress is applied by the bending moment in a cross section having a plane perpendicular to the longitudinal direction of the arm 14 as a cutting plane. An area where compressive stress acts is generated. In this case, there is a boundary surface between the region where the tensile stress is applied and the region where the compressive stress is applied, and there is a surface where neither the tensile stress nor the compressive stress is applied. When the neutral surface 18 is used as a boundary, the outer side of the curved shape of the arm 14 and the side where the tensile stress is generated is the outer side of the arm 141, and the inner side of the curved shape of the arm 14 is the compressive stress. The side to be generated is referred to as an arm inner side 142 (FIG. 5A). That is, tensile stress acts on the arm outer side 141, and compressive stress acts on the arm inner side 142 (FIG. 5B). In particular, when the arm 14 is formed in a line-symmetric shape, tensile stress concentrates on the arm outer side 141 at the line-symmetric center portion of the arm 14.

  As described above, when a load is applied in a direction in which the heel pressing portions 12 are brought closer to each other, a tensile stress acts on the arm outer side 141. When the tensile stress exceeds the arm strength, the portion where the tensile stress is particularly strong among the portions where the tensile stress is applied becomes the starting portion 19 and the arm 14 is bent (FIG. 5C).

  The portion that is likely to become the folding start portion 19 is the entire portion where the tensile stress acts, that is, the arm outer portion 141 portion, but the portion that tends to be the folding start portion 19 specifically is perpendicular to the longitudinal direction of the arm. This is the portion of the outer arm 141 having a cross-sectional shape that is farthest from the neutral surface 18, that is, the outermost arm portion. This is because the tensile stress is stronger than the other portions of the arm 14. In addition, when the eyelid opening device 10 is U-shaped and line-symmetrical, it is the arm outer side 141 at the center of symmetry as shown in FIG. . This is because the tensile stress is very strong in the arm 14.

  In addition, when compared with the above-described portion, the bent start end portion 19 is less likely to be formed. However, when the arm cross-sectional shape perpendicular to the longitudinal direction of the arm is substantially circular, the arm cross-sectional shape is illustrated in FIG. As shown, in the cross section of the arm, the direction from the substantially circular center to the outermost arm 141a is the x axis, and the direction passing through the substantially circular center and perpendicular to the x axis is the y axis. When the tangent to the arm 14 is expressed as a function of y = ax + b (where a and b are constants), a portion where the absolute value of the inclination a of the tangent to the arm 14 exceeds 1 on the outer arm 141 is broken. It can be a starting end portion 19 (a region indicated by a broken-line arrow outside the arm). This is because this portion is relatively disposed on the outermost arm 141a as compared with the other portions and is easily affected by tensile stress.

  Hereinafter, in the arm cross section, the distance on the x-axis is also referred to as “thickness”, and the cross-sectional area of the arm cross section is also referred to as “thickness”.

  The neutral surface 18 tends to be located in the middle part of the thickness of the arm 14, and when the arm cross-sectional shape perpendicular to the longitudinal direction of the arm is substantially circular, the tendency becomes stronger. In the case of a perfect circle shape or a regular ellipse shape, the tendency is further increased.

  In consideration of the strength of the arm 14 as described above, the present inventor, in a portion other than the portion where the tensile stress generated when applying a load in the direction in which the heel pressing portions 12 are brought closer to each other, It has been found that by providing the gate portion 15 of the arm 14, the risk of breakage of the eyelid opening device 10 is reduced.

In addition, about the specific mechanism which concerns on the breakage | opening device 10, although it is guessed, the following mechanisms can be considered.
As described above, when the opening device 10 is manufactured, the resin is injected into the mold 16 by injection molding. However, in the gate portion 15 of the opening device 10, In addition, the polymer chain 20 in the resin is oriented in the injection direction.
As shown in FIG. 16, a mold resin injection part 67 is provided in the mold 66 so that the opening device is U-shaped and line-symmetrical, and the gate part 65 is provided on the outermost side of the arm at the center of symmetry. In this case (FIG. 16A), since the polymer chain 20 is oriented perpendicular to the direction in which the tensile stress acts (FIG. 16B), the bundle of polymer chains 20 is torn by the tensile stress. As a result, the gate portion 65 is bent, and the arm 64 is bent as the starting end portion 19 (FIG. 16C).

  On the other hand, in the present embodiment, as shown in FIG. 4 and the like, the arm 14 is provided on a portion other than the portion where the tensile stress generated when the load is applied in the direction in which the collar pressing portions 12 are brought closer to each other. The gate portion 15 is provided.

  For example, as shown in FIG. 6, the portion where the tensile stress generated in the arm 14 is the maximum is the most distant portion from the neutral surface 18 in the arm cross-sectional shape perpendicular to the longitudinal direction of the arm. The outer side 141a is mentioned. This is because the arm outermost 141a is a portion where tensile stress is particularly easy to work.

The gate portion 15 may be provided in a portion other than the portion where the tensile stress is maximized, that is, a portion where there is little possibility of becoming the folding start portion 19. For example, the gate portion 15 is provided in the vicinity of the end portion 14 a of the arm 14. Also good.
Specifically, a thermoplastic resin may be injected from at least one end section 14c (FIG. 1) of the arm 14. This is because it is not necessary to orient the polymer chain 20 in the vertical direction with respect to the tensile stress.
Further, in the end portion 14 a of the arm 14, thermoplastic resin may be injected from the arm outer side 141 as well as from the arm inner side 142. This is because when using the eyelid opening device 10, tensile stress is relatively difficult to work near the end portion 14 a of the arm 14.
Furthermore, a plurality of gate portions 15 may be provided. For example, a gate portion may be provided on each of the upper and lower heel presser portions 12 and the arm 14 to inject a thermoplastic resin, or a plurality of gate portions 15 may be provided on the arm 14. In this case, it is better to design so that the resin injected from a plurality of gates does not meet at a position where a strong tensile stress is applied.

  Further, when the entire arm 14 and the heel presser portion 12 are integrally molded, the gate portion 15 may be provided in the heel presser portion 12. Specifically, the gate portion 15 may be provided on the curved outer side of the U-shaped curved plate that is a portion that does not touch the patient's heel. This is because the patient is not burdened and the polymer chain 20 is not oriented in the vertical direction with respect to the tensile stress.

  As shown in FIG. 6A, in this embodiment, it is not necessary to provide the gate 15 in the arm outermost portion 141a. However, in the arm outer side 141 where the tensile stress is applied, the arm 14 is bent, that is, in the x-axis direction. It is preferred to inject the resin in a direction that is not as parallel as possible, preferably perpendicular. This is because the bending of the arm 14 can be suppressed by aligning the polymer chain 20 in a direction that is not parallel to the direction in which the arm 14 is bent, preferably perpendicularly.

  Furthermore, it is preferable to provide the gate portion 15 on the arm inner side 142 which is a portion where there is no possibility of becoming the bent start portion 19, that is, a portion where compressive stress is generated instead of tensile stress. This is because if the tensile stress is not generated, the possibility that the bundle of the polymer chains 20 in the gate portion 15 is torn is extremely reduced in the first place, and the possibility that the gate portion 15 is broken and becomes the starting end portion 19 is extremely reduced.

Specifically, as shown in FIG. 6, when the arm cross-sectional shape perpendicular to the longitudinal direction of the arm is substantially circular, in the arm vertical cross-section, from the substantially circular center to the arm outermost side 141a. The direction to go is the x axis, and the direction perpendicular to the x axis passing through the substantially circular center is the y axis. In this xy coordinate system, the tangent to the arm is a function of y = ax + b (where a and b are constants). As shown, the arm gate portion 15 is provided in a portion where the absolute value of the inclination a of the tangent to the arm 14 does not exceed 1 on the arm outer side 141 or the arm inner side 142 where no tensile stress acts. preferable. In particular, it is preferable that the gate portion 15 of the arm is provided on the arm inner side 142 where no tensile stress acts. This is because the influence of the tensile stress on the arm inner side 142 is small, and the influence of the orientation of the polymer chain 20 of the gate portion 15 can be reduced.

  As for the position of the gate portion 15, the gate portion 15 at the time of injection molding of the arm 14 is provided particularly on the arm innermost side 142 a that is the portion farthest from the neutral surface 18 in the arm inner side 142. preferable. This is because the tensile stress is the part that is least affected by the tensile stress, and the compressive stress acts strongly in the opposite direction to the tensile stress that causes the bundle of polymer chains 20 in the gate portion 15 to be torn.

  Further, as shown in FIGS. 7A to 7D, a mold resin injection portion 17 is provided in the mold 16 so that the gate portion 15 of the arm is provided on the arm inner side 142 in the center of symmetry, and the opener 10 is preferably produced. Further, the portion where the bundle of polymer chains 20 is not easily torn and the compressive stress is most exerted, that is, the innermost arm 142a which is the portion farthest from the neutral surface 18 in the inner arm 142 of the center of symmetry, More preferably, a gate portion 15 is provided.

  In summary, in the present embodiment, the gate portion 15 of the arm 14 is provided in a portion other than the portion that tends to become the folding start portion 19. By providing the gate portion 15 in a place where it is difficult to become the folding start portion 19, the possibility of breakage of the arm 14 with the gate portion 15 as the folding start portion 19 can be reduced, and the strength as a product can be improved. Furthermore, when the surgeon pinches the opener 10 with a finger, it is possible to reduce the concern about whether the arm 14 is broken, and the stress on the surgeon can be reduced. In addition, the necessary function of opening the upper and lower eyelids with an appropriate opening force can be sufficiently achieved.

  In the eyelid opening device 10 of the present embodiment, as shown in FIG. 8A, a U-shaped and line-symmetrical curve is formed, and a portion in a range of at least 4 mm in the longitudinal direction of the arm around the center of symmetry. In the cross-sectional area of the arm cross-section perpendicular to the longitudinal direction of the arm, the cross-sectional area of the arm in the range of at least 4 mm in the longitudinal direction of the arm around the center of symmetry is It is preferable that an arm larger than the cross-sectional area of the other portion is formed, and the gate portion 15 is provided on the innermost arm 142a at the symmetrical central portion of the arm.

  When the arm 14 is configured as described above, the pre-finishing opener 10a, which is a molded product, is taken out of the opener forming die 16 in the manufacturing process of the opener 10, and the pre-finishing opener 21 is heated by the heated nipper 21. When the gate portion 15 of 10a is cut and removed, even if the gate portion 15 is provided on the arm inner side 142, the work space by the nipper 21 can be provided wider than a simple U-shaped arm. The hindrance to work can be reduced (FIG. 8B (f) (g)). In addition, as described above, by providing the gate portion 15 on the arm inner side 142, the possibility of breakage of the arm 14 with the gate portion 15 folded and the starting end portion 19 can be reduced. Strength can be improved.

Furthermore, although the arm as a whole is U-shaped, the arm 14 is formed in a substantially U-shape in which two substantially right-angled portions are provided in the U-shaped curved portion. It is also preferable to provide the gate portion 15 on the innermost arm 142a of the portion. The work space by the nipper 21 can be further widened, and the hindrance of work by the arm 14 can be further reduced.
In the present embodiment, it is preferable that the substantially U-shape is a substantially U-shape that is a line-symmetric shape, but the substantially right-angled portion includes an angle slightly shifted from a right angle,
As shown in FIG. 3D, a part of the arm 14 is curved so that it can be easily picked with a finger.

As described above, when the gate portion 15 is provided on the innermost arm 142a in the center of symmetry of the arm 14, as shown in FIG. 19, the thermoplastic resin moves in the direction from the inner side to the outer side in the U-shaped curve. Preferably it is injected by runner 28.
Specifically, a short cylindrical runner 28 installed in the mold resin injection portion 17 is connected to the gate portion 15 of the arm 14 substantially parallel to the resin injection direction. The long cylindrical spool 27 installed in the mold 16 is connected to the runner 28 at a predetermined angle and connected in the vicinity of the end of the spool 27. Thus, it is preferable to arrange the spool 27 and the runner 28 and to inject the thermoplastic resin from the gate portion 15 through the runner 28 from the spool 27 to produce the arm 14.

(Embodiment 2)
Hereinafter, another embodiment according to the present invention will be described with reference to FIG. 8A used in the first embodiment.
8A shows the configuration of the eyelid opening device of the embodiment, (a) is a perspective view, (b) is a plan view, (c) is a side view, (d) is a front view, and (e) is a view of (d). It is an enlarged view of Ie part. Moreover, although mentioned also in Embodiment 1, FIG. 2 is a figure which shows the use condition.

  As shown in FIGS. 8A and 2, the eyelid opening device 10 is coupled to one wire-like arm 14 made of a resin that is bent so as to have a spring property, and both ends 14 a of the arm 14. The eyelid 101 has two eyelid pressers 12 that are hooked on the upper eyelid 102 and the lower eyelid 103, respectively.

  The opener 10 is configured such that at least the arm 14 is formed as a resin molded product, and the open state is maintained by the spring repulsive force of the arm 14.

Here, mainly the parts different from the first embodiment will be described.
As shown in FIG. 5 showing the stress acting on the arm 14, in the opener 10 of the present embodiment, when a load is applied in a direction in which the heel pressers 12 are brought closer to each other, the heel presser 12 is returned to its original position. A spring repulsive force (hereinafter also referred to as an opening force) acts on the arm 14. At this time, in order to have an opening force that is not inferior to the patient's closing force, it is necessary to increase the thickness of the arm 14.

  With respect to such considerations regarding the opening force of the arm 14, the present inventor adjusts the spring repulsive force generated when a load is applied in a direction in which the collar holding portions 12 approach each other. By providing the force adjusting portion 23 on the inner side 142 of the arm, the region where the arm 14 is easily deformed when a load is applied can be increased or decreased, and the spring repulsive force of the arm 14 can be appropriately controlled. It has been found that a wide variety of opening devices with different opening forces can be easily obtained while ensuring the opening force of the opening device 10 without increasing the thickness.

  Here, the opening force adjusting unit will be described. The opening force adjusting portion is provided to increase or decrease the region where the arm 14 is easily deformed when a load is applied.

  As shown in FIG. 9, generally, when the heel presser portions 12 are brought close to each other and are displaced by the same displacement amount D, the arm 24 is easily deformed, that is, the arm 14 is easily deformed. The larger the length, the smaller the load required to displace the presser foot 12 by the displacement amount D, that is, the opening force of the opening device 10 decreases.

  Here, the length of the easily deformable region 24 in the arm 14 is determined by the position of the fulcrum 25 with respect to the load on the arm inner side 142. In the present embodiment, the position of the fulcrum 25 can be adjusted by the opening force adjusting unit.

  For example, as shown in FIG. 10, the fulcrum adjustment is performed so that the portion that becomes the fulcrum 25 when the load is applied is shifted in the arm inner side 142 toward the arm tip portion (from the broken line in FIG. 10A). This is done by providing the opening force adjusting portion 23 so as to shift in the direction opposite to the direction of the arm tip (shifted from the broken line to the solid line in FIG. 10B).

  Further, there may be a difference between the opening force by the upper and lower pressing portions and the opening force by the lower and lower holding portion. Specifically, as shown in FIG. 10 (c), when it is desired to increase the opening force for the patient's upper arm, the opening force adjusting portion 23 is moved toward the arm distal end on the upper eyelid presser 121 side. Shifting is performed in the direction opposite to the arm tip direction on the side of the lower presser foot 122. Thereby, each desired opening force can be given with respect to the upper and lower eyelids.

  Thus, by providing the arm inner side 142 with the opening force adjusting portion 23 that adjusts the spring repulsion force that is generated when a load is applied in the direction in which the collar pressing portions 12 are brought closer to each other, the arm 14 is excessively moved. Since the opening force of the opening device 10 can be ensured without increasing the thickness, it is possible to suppress the hindrance to the operation such as a surgical instrument hitting and to reduce the feeling of pressure on the surgical field. Furthermore, simply by changing the position where the opening force adjusting portion 23 is provided, various types of opening devices 10 having different opening forces can be easily obtained.

  In addition to these advantages, from the viewpoint of reinforcement of the arm 14, which will be described in detail later, by providing the opening force adjusting portion 23, the fulcrum 25 with respect to the load can be provided at a plurality of locations, and the tensile stress is at one location. Can prevent you from concentrating on. Thereby, like Embodiment 1, the possibility that the arm 14 may be damaged when the heel pressing portions 12 are brought close to each other can be reduced.

  In addition, if the opener 10 is made of a thermoplastic resin formed by injection molding and the presser foot 12 and the arm 14 are integrally molded, a wide variety of openers 10 having different open forces are produced. This advantage is further increased.

  As shown in FIG. 11, a hole 26 may be formed in the eyelid opening device 10. In other words, the opening device 10 may be configured such that the arm 14 is bridged by the opening force adjusting unit 23 (FIG. 11A).

  The opening force adjusting portion 23 may be integrally formed with the arm 14 or may be provided separately. However, it is preferable that the opening force adjusting portion 23 is provided integrally from the viewpoint of cost reduction in mass production. .

  At this time, for example, an opening force adjusting portion 23 that is curved so as to protrude toward the bottom of the U-shaped arm 14 when viewed from a plane may be provided (FIG. 11B). Compared to the case where the opening force adjusting portion 23 is provided in a linear shape, the fulcrum when a load is applied can be slightly shifted in the direction opposite to the arm tip direction, and the opening force adjusting portion 23 can slightly increase the deformable region 24 in the arm. Thereby, the opening force strengthened by the opening force adjusting unit 23 can be finely adjusted.

On the contrary, for example, an opening force adjusting portion 23 that is curved so as to be convex toward the arm tip side when viewed from a plane may be provided (FIG. 11C). Compared to the case where the opening force adjusting portion 23 is provided in a linear shape, when the load is applied, the opening force adjusting portion 23 serves as a cushion and can reduce the possibility of the arm 14 being damaged. Inferred.

  Here, the opening force adjusting unit 23 formed in a linear shape or curved is described, but the opening force adjusting unit 23 may be bent a plurality of times, as shown in FIGS. 11 (d) and 11 (e). Thus, an opening force adjusting portion 23 formed in a shape bent at least once may be provided.

  Furthermore, as shown in FIG. 11 (f), a plurality of opening force adjusting sections 23 may be provided. This is because subtle control of the opening force becomes possible.

  Moreover, as shown in FIG.11 (g), the eye opening device 10 may be comprised so that the some hole part 26 may be formed. In other words, the opening device 10 may be configured such that the arm 14 is bridged at three or more locations by the opening force adjusting unit 23. This is because by increasing the number of places where the arm 14 is bridged by the opening force adjusting portion 23, an appropriate opening force can be obtained and the arm 14 can be reinforced.

  Further, as shown in FIG. 11 (h), by making the portion of the arm 14 that may become the folding start end portion 19 thicker than the other portions, the folding suppression region described later is adjusted with the opening force adjustment. The part 23 may also serve.

As described above, when the opening force adjusting portion 23 is provided so that the hole portion 26 exists, in addition to having an appropriate opening force as described above, the presence of the hole portion 26 results in that portion. The cost of raw materials can be reduced. In particular, the opener 10 in which the presser foot 12 and the arm 14 are integrally molded can produce a large number of openers 10 having different opening forces, and this advantage is further increased.
Further, the hole 26 can be stored by being penetrated by a holding rod or the like, and the storage becomes easy.
Furthermore, the presence of the hole 26 expands the surgical field, which is an area that can be visually recognized by the surgeon, and can reduce the feeling of pressure on the surgeon.
As a result, it is possible to obtain a retractor that has an appropriate opening force, reduces stress on the operator, and sufficiently performs the necessary function of opening the upper and lower eyelids.

  Note that the curved shape of the arm 14 is, for example, a U-shaped arm 14 as shown in FIG. 13A and is substantially U-shaped with the curved outer side and / or curved inner side partially deformed (FIG. 13A). (A)) Even when it is W-shaped (FIG. 13A (b)) or curved several times (FIG. 13A (c)), the opening force adjusting unit 23 as described above By providing the above, the above-described effects can be obtained.

In order to reduce the risk of breakage of the arm 14 in addition to having an appropriate opening force as described above, the opening force adjusting portion 23 is generated on the arm outer side 141 as shown in FIG. It is also preferable that the fold suppression region 22 is provided in a direction from the portion where the tensile stress is maximized toward the arm inner side 142.
The opening force adjusting portion 23 also serves as the breakage suppression region 22, thereby reducing the risk of breakage of the opening device 10 while ensuring the opening force of the opening device 10 without excessively thickening the arm 14. be able to.

  Here, the folding suppression region 22 will be described. The folding suppression region 22 is provided so that the hole 26 is not formed in the eyelid opening device 10, and the portion where the tensile stress generated on the arm outer side 141 is maximized does not become the bending start portion 19. It is an arm reinforcement point.

  This arm reinforcement is performed, for example, by giving a thickness to the portion of the arm 14 where the tensile stress is maximum so that the bending does not easily occur, or by increasing the thickness of the arm 14.

  It should be noted that the portion where the arm 14 is thickened or thickened as described above may be at least a portion where the tensile stress is maximized, and the other portions may be thickened without increasing the thickness. It is not necessary. Furthermore, the folding suppression region 22 may be provided separately after the above-described opening force adjusting unit 23 is provided. This is to prevent the arm 14 from obstructing the operator's work by reducing the feeling of pressure on the operative field by not thickening or thickening the portion other than the bending suppression region 22.

  In particular, when the arm 14 is curved in a U-shape, the curvature radius of the curved shape of the outer arm 141 at the portion where the tensile stress generated on the outer arm 141 is maximized is given to the inner arm 142. It is preferable to provide the folding suppression region 22 by making it smaller than the curvature radius of the curved shape of the arm inner side 142 in the portion where the generated compressive stress is maximum.

  In other words, the curvature of the curved shape of the arm outer side 141 (the reciprocal of the radius of curvature) at the portion where the tensile stress generated on the arm outer side 141 becomes the maximum is the portion at which the compressive stress generated on the arm inner side 142 becomes the highest. It is preferable to provide the bending suppression region 22 by making it larger than the curvature of the curved shape of the arm inner side 142 (the reciprocal of the radius of curvature) (FIG. 13A (d)). Thereby, it is not necessary to thicken the entire arm 14, and it is possible to increase the thickness of the arm 14 where the tensile stress becomes maximum and the fold is likely to occur. Furthermore, by thickening the arm inner 142 instead of the arm outer 141, it is possible to suppress the arm 14 from interfering with the operator's work.

  Further, when the arm cross-sectional shape perpendicular to the longitudinal direction of the arm is substantially circular, the arm cross-sectional shape including a point where the tensile stress generated in the arm outer side 141 is maximum in the arm cross-sectional shape. It is preferable to provide the fold suppression region 22 by maximizing the distance from the arm outermost side 141a to the arm innermost side 142a over the arm 14 (FIG. 13B (e)). This is because the arm 14 is difficult to break as described in the first embodiment. Furthermore, by thickening the portion of the entire arm 14 where the tensile stress is maximum, it is not necessary to increase the thickness of the entire arm 14, but the portion where the tensile stress is maximum and the fold is likely to occur in the arm 14 is thickened. can do.

  Further, regarding the thickness of the arm 14, in the arm cross-sectional shape perpendicular to the longitudinal direction of the arm, the cross-sectional area of the arm cross-sectional shape including the point where the tensile stress generated in the arm outer side 141 is maximized is It is also preferable to provide the folding suppression region 22 by maximizing the arm 14. Thereby, it is possible to reinforce a portion where the arm 14 is likely to be bent, and to prevent the arm 14 from being bent. By suppressing the breakage of the arm 14, the strength of the eyelid opening device 10 as a product can be improved. In addition, it is not necessary to make the thickness of the arm 14 excessively large in order to have a rebound resilience that has an opening force that does not lose the closing force while suppressing breakage of the arm 14.

  By configuring the eyelid device in this way, it is possible to reduce the feeling of pressure on the surgical field due to the thickness and thickness of the arm 14, and to reduce the stress on the operator. In addition, the necessary function of opening the upper and lower eyelids can be fulfilled sufficiently.

In particular, when the arm 14 is curved in a U-shape and a line-symmetric shape, and the arm cross-sectional shape perpendicular to the longitudinal direction of the arm is a substantially circular shape, the arm at the symmetrical center portion of the arm 14 It is preferable that the distance from the outermost side 141a to the arm innermost side 142a is maximized over the arm 14 (FIG. 13B (e)). Further, it is preferable that the cross-sectional area of the symmetrical central portion of the arm 14 is maximized.
This is because the bending of the arm 14 is likely to occur at the center of symmetry, and if this portion is reinforced, the bending of the arm 14 can be suppressed. Furthermore, this is because the strength of the arm 14 can be controlled without making the entire arm 14 thicker and / or thicker by making the arm inner side 142 particularly thick and / or thicker at the center of symmetry.

Also, in this case, the inner side of the curved portion in the range of at least 4 mm in the longitudinal direction of the arm (in other words, the bottom portion of the U-shape) is set to a straight shape instead of the curved shape. The cross-sectional area of the arm in the range of at least 4 mm in the longitudinal direction of the arm as a center is preferably larger than the cross-sectional area of the other part. This is because an appropriate opening force can be obtained by forming the arm 14 under the above-described conditions.
At this time, the thickness of the arm 14 in the above range may be substantially uniform (FIG. 13B (f)). Further, as shown in FIGS. 13A (b) to 13 (d) and FIG. 13B (f), a plurality of maximum curvature portions may be provided on the arm inner side 142 in the curved shape of the U-shaped and line-symmetrical arm 14. Since the arm 14 takes such a shape, the tensile stress is distributed to a plurality of maximum curvature portions on the arm inner side 142, and therefore, the tensile stress is prevented from being concentrated at one place in the symmetrical central portion as shown in FIG. be able to.

  As a means for such reinforcement, the arm 14 may be formed so that the cross-sectional area of the arm gradually increases from both arm end portions 14a and 14b (FIG. 13B (g)). This is because by having such a shape, the surgical field becomes wider than when the entire arm 14 is thickened, and the surgeon's stress can be reduced.

  Further, similarly to the first embodiment, the arm 14 and the bar pressing portion 12 may be made of a thermoplastic resin molded by injection molding, and may be configured as an integrally molded product of resin. Since the whole is formed by integral molding of a thermoplastic resin, it can be easily mass-produced at low cost. As a result, it can be used in a disposable manner, and sterilization is not required, and a large amount of usage requirements can be met. Again, since the closing force varies depending on the patient, it is possible to prepare the opening device 10 having various opening forces in advance and use the disposable opening device 10 according to the patient. .

  In the manufacture of the eyelid opening device 10 in this embodiment, a method of scraping a structure from a block-shaped resin material, a method of polymerizing and curing in a resin mold or a mold, or injection using a thermoplastic resin Although a resin molding method such as a molding method may be used, injection molding is preferable in that it can be combined with the first embodiment and a large amount of products can be manufactured.

  As described above, the opening device 10 has a structure in which the two lever pressing portions 12 are provided at both ends 14a of the arm 14 having a spring property. The necessary function of opening the caskets 102 and 103 can be performed easily and sufficiently. And as shown in FIG. 2, although it is resin, sufficient operative field can be ensured. In addition, since the arm is opened by the spring repulsive force of the resin arm 14 that exhibits more supple elasticity than metal, there is no pain in the case of a patient who cannot open the arm greatly, and the vitreous body pressure rises. There is no risk of inducing trouble.

  Moreover, by using as a disposable type, the possibility of breakage due to repeated fatigue of the resin can be eliminated, so safety can be improved. Moreover, when the part (the heel presser part 12) which touches the heels 102 and 103 directly is made of a resin whose hardness is lower than that of the metal, a soft contact feeling can be given to the patient, and the burden on the patient can be reduced. The

  Furthermore, as described above, according to the embodiment of the present invention, the necessary function of opening the upper and lower eyelids can be sufficiently achieved while reducing the stress applied to the operator while having an appropriate opening force. it can.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. In particular, as in the case of the eyelid opening device shown in FIG. 8A, by combining the above embodiments, the necessary function of reducing the stress applied to the operator and opening the upper and lower eyelids while having an appropriate opening force It can be expected that a further synergistic effect will be exhibited for fulfilling the above.

  In particular, although the arm as a whole is U-shaped, the arm 14 is formed in a substantially U-shape by partially deforming the bottom of the U-shape and the gate portion 15 is provided on the arm inner side 142 (implementation). When the first embodiment is applied to the second embodiment, the arm 14 is provided with the opening force adjusting portion 23, and the working space by the nipper 21 can be provided wide when the gate portion 15 is cut and removed. In addition, the strength of the arm 14 can be improved, and the opening force can be adjusted as appropriate, which has a synergistic effect of reducing stress on the operator.

  In addition to this synergistic effect, when the arm 14 and the heel presser 12 are configured as an integral molded product of thermoplastic resin as a whole, the above-described arm strength is maintained and the subtle force against the opening force is delicate. While having excellent effects such as controllability, it is possible to easily produce a large number of openers with various spring repulsive forces at low cost, enabling disposable use and sterilization. It is possible to meet a large amount of usage requirements as unnecessary.

Example 1
Hereinafter, this embodiment will be described.
As shown in FIG. 7, PMMA, which is a thermoplastic resin having fluidity at high temperature, was injected into the mold 16 from the mold resin injection section 17 and cooled.
Next, the pre-finishing opener 10a was taken out from the mold 16, and the gate part 15 was cut and removed by the heated nipper 21 to produce the opener 10 according to this example shown in FIG.
At this time, as shown in FIG. 7C and FIG. 17, the curved shape of the arm 14 is U-shaped and line-symmetrical, and the gate portion 15 is provided on the arm innermost side 142 a in the symmetrical central portion of the arm 14. The character width was about 32 mm, and the thickness of the arm 14 was 2.2 mm in diameter.

(Example 2)
Further, the eyelid opening device 10 of this example was manufactured by the same method as that of Example 1. However, in this embodiment, unlike the first embodiment, as shown in FIG. 8A, the inner side of the curved portion in the range of 6 mm in the longitudinal direction of the arm, in which the symmetrical central portion is located at the center, is linear, and the symmetrical central portion is The cross-sectional area of the arm cross section perpendicular to the longitudinal direction of the arm in the arm in the range of 6 mm in the longitudinal direction of the arm as the center is larger than the cross-sectional area of the other portions.

(Comparative example)
A comparative opener 60 was also produced in the same manner as in Example 1. However, in the comparative example, unlike the first and second embodiments, as shown in FIG. 15, the gate portion 65 is provided on the arm outermost side 641 a in the symmetrical center portion of the arm 64.

  A universal testing machine (universal testing machine MINI44 type manufactured by Instron Co., Ltd.) is used for the eyelid opening device according to this example and the comparative example, and as shown in FIG. 17, the boundary part between the curved part and the straight part of the arm On the other hand, a load was applied in a direction in which the presser foot portions were brought closer to each other, and compression was performed at a speed of 100 mm / min. The result is shown in FIG.

In the eyelid opening device 10 in Example 1 and Example 2, even when the compression displacement of the arm was 15 mm or more and the compression load was 25 N (about 2.5 kg weight) or more, the arm did not break.
On the other hand, in the eyelid opening device 60 in the comparative example, when the compression displacement of the arm is 8.5 mm and the compression load is 6.4 N (about 0.6 kg weight), the gate portion 65 is folded and the starting end portion is used. The arm broke.

(Example 3)
Furthermore, when the upper and lower eyelids are opened using the opener, the opening width varies depending on the treatment contents and individual patient differences, but considering that the opening width is usually 15 mm or more, it is between the central part of the curved plate in the presser foot. In addition to Examples 1-2, the repulsive force when the distance of 15 mm was pushed down to 15 mm was set such that the cross-sectional area of the arm in the range of 10 mm in the longitudinal direction of the arm was larger than the cross-sectional area of the other parts. It measured similarly using the universal testing machine (Instron universal testing machine MINI44 type | mold) with respect to the opener of Example 3. FIG.

  As a result, the repulsive force of the opening device of Example 1 was 66 gf, whereas the repulsive force of the opening device of Example 2 was 70 gf, which was increased by about 6%. Moreover, the repulsion force of the eyelid opening device of Example 3 was 80 gf, which was increased by about 20%.

  As a result, it was found that the repulsive force of the eye-opening device 10 can be controlled by increasing the thickness of the vicinity of the center of symmetry in the arm 14.

DESCRIPTION OF SYMBOLS 10 Opening device 10a Pre-finishing opening device 102 Upper rod 103 Lower rod 12 Rod pressing portion 121 Upper rod pressing portion 122 Lower rod pressing portion 12a Inner insertion piece 12b Outer pressing piece 14 Arm 141 Arm outer side 141a Arm outermost side 142 Arm inner side 142a Inner side of arm 14a Arm ends 14c Cross section at both ends of arm 15 Gate portion 16 Mold for mold opening 17 Mold resin injection portion 18 Neutral surface 19 Bending start portion 20 Polymer chain 21 Nipper 22 Bending suppression region 23 Open Repulsive force adjusting part 24 Deformable area 25 Support point 26 Hole part 27 Spool 28 Runner 60 Opener 62 Opening presser part 62a Inner insert piece 62b Outer presser piece 64 Arm 64a Arm both ends 65 Gate part 66 Opening tool mold 67 Mold resin injection part

Claims (13)

It has one arm made of thermoplastic resin formed into a curved shape by injection molding so as to have springiness, and two hook holding parts that are respectively coupled to both ends of the arm and hooked on the upper hook and the lower hook, respectively. And an opener configured to keep the open state by the spring repulsive force of the arm,
When a bending load is applied to the arm in a direction in which the presser foot portions are brought closer to each other, the arm is on the outer side of the curved shape and the side where the tensile stress is generated, with the neutral surface of the arm as a boundary. And when the inside of the curved shape and the side where the compressive stress occurs is the inside of the arm,
The resin injection part of the arm is provided in a part other than the part where the tensile stress generated when applying a load in a direction in which the pressing parts are brought closer to each other,
An opening force adjustment unit that adjusts the spring repulsion force that is generated when a load is applied in a direction in which the lid holding portions are brought closer to each other,
A curved shape that extends in the direction opposite to the linear shape or the curved shape inside the arm, spanning the inside of the arm,
The bottom part of the curved shape inside the arm,
The eyelid opening device is provided inside the arm so as to fill a region surrounded by the arm.
However, the neutral surface is a region in which tensile stress is applied by the bending moment and a compressive stress in a cross section in which a plane perpendicular to the longitudinal direction of the arm is cut when a bending moment is applied to the arm. A region is formed, but is a boundary surface between a region where tensile stress is applied and a region where compressive stress is applied, and is a surface where neither tensile stress nor compressive stress is applied.   2. The eyelid opening device according to claim 1, wherein the arm, the eave pressing portion, and the opening force adjusting portion are integrally formed of a thermoplastic resin.   3. The resin injection portion at the time of injection molding of the arm is provided in a portion other than the outermost arm which is the portion farthest from the neutral surface on the outer side of the arm. Opening device described in 1.   The eyelid opening device according to claim 3, wherein a resin injection portion for injection molding of the arm is provided inside the arm.   5. The opening according to claim 4, wherein a resin injection part for injection molding of the arm is provided on the innermost side of the arm, which is the part farthest from the neutral surface on the inner side of the arm. A fixture.   6. The eyelid opening device according to claim 1, wherein the arm is curved in a U shape.   The eyelid opening device according to claim 6, wherein the shape of the arm cross section, which is a cross section cut along a plane perpendicular to the longitudinal direction of the arm, is substantially circular.   In the arm cross-section, the direction from the substantially circular center to the outermost side of the arm, which is the portion farthest from the neutral surface outside the arm, is the x axis, and the direction perpendicular to the x axis through the substantially circular center is the y axis. In the xy coordinate system, when the tangent to the arm is expressed as a function of y = ax + b (where a and b are constants), the absolute value of the inclination a of the tangent to the arm is 1 outside the arm. The eyelid opening device according to claim 7, wherein the resin injection portion is provided in a portion not exceeding or inside the arm. The arm is curved in a line-symmetric shape,
The eyelid opening device according to claim 7, wherein the resin injecting portion is provided on the innermost side of the arm at the symmetrical center portion of the arm.
However, the innermost side of the arm means a part farthest from the neutral surface on the inner side of the arm.   The opening force adjusting portion according to claim 1, wherein the opening force adjusting portion is also a folding suppression region provided in a direction from the portion where the tensile stress generated on the outer side of the arm is maximum toward the inner side of the arm. A fixture. The arm cross-sectional shape perpendicular to the longitudinal direction of the arm is substantially circular,
In the arm cross-sectional shape perpendicular to the longitudinal direction of the arm, the distance from the arm outermost side to the arm innermost side of the arm cross-sectional shape including the point where the tensile stress generated outside the arm is maximum is applied to the arm. The eyelid opening device according to claim 10, wherein the opening device is maximum.
However, the outermost arm means the part farthest from the neutral surface outside the arm, and the innermost arm means the part farthest from the neutral surface inside the arm. The arm cross-sectional shape perpendicular to the longitudinal direction of the arm is substantially circular,
In the arm cross-sectional shape perpendicular to the longitudinal direction of the arm, the cross-sectional area of the arm cross-sectional shape including a point where the tensile stress generated outside the arm is maximum is maximized over the arm. The eyelid opening device according to claim 10. The arm is curved in a U-shape and a line-symmetric shape,
The cross-sectional area of the arm cross section perpendicular to the longitudinal direction of the arm in the arm in the range of at least 4 mm in the longitudinal direction of the arm around the center of symmetry is larger than the cross-sectional area of the other portions. The eyelid opening device according to claim 11.