Enteral nutrition syringe

Abstract

To provide an enteral nutrition syringe which can be connected to a male connector for enteral nutrition and achieves reduced pressing force for pressing contents out.SOLUTION: An enteral nutrition syringe has a cylindrical barrel 100 having a nozzle 102 where a male connector can be inserted into a tip end. The nozzle 102 has a minimum vale of an inner diameter of 3.0 mm or more and integrally includes a first tapered part 102a in which an inner diameter is gradually reduced to a tip end side and a second tapered part 102b in which an inner diameter expands to the tip end side from a tip end of the first tapered part 102a so that the male connector can be inserted. A length of the first tapered part 102a is longer than that of the second tapered part 102b, a tapered angle of the first tapered part 102a is larger than that of the second tapered part 102b, and an inner diameter at a base end of the first tapered part 102a is larger than an inner diameter at a tip end of the second tapered part 102a.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a syringe for enteral nutrition.

Background Art

[0002] Medical connectors have different specifications for each field so as not to misconnect different lines. In the field of enteral nutrition, there is a standard (ISO80369-3) in which a male connector is provided on the downstream side of the line close to the patient and a female connector is provided on the upstream side of the line. As a syringe equipped with a female connector conforming to the standard, a syringe having a female luer portion formed at the tip of the barrel has been marketed with a common design by each company (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the applicant compared and analyzed a syringe with a common design and an old-standard syringe, it was confirmed that the syringe with a common design has a greater pressing force when extruding the liquid in the barrel than the old-standard syringe. Enteral nutrition solutions are different from ordinary injection solutions, and some have a high viscosity. In particular, the mixer food used in home administration has a high viscosity, and a large force must be applied to the plunger when sucking or extruding the liquid. For women and the elderly who perform home administration, the increased force associated with sucking or pressing the liquid is a problem.

[0005] An object of the present disclosure is to realize a syringe for enteral nutrition that can be connected to a male connector for enteral nutrition and suppresses the pressing force for extruding the contents to a small value. [Means for solving the problem]

[0006] One embodiment of the enteral nutrition syringe of the present disclosure comprises a cylindrical barrel having a nozzle into which a male connector can be inserted at the tip, wherein the nozzle integrally has a first tapered portion having a minimum inner diameter of 3.0 mm or more and gradually decreasing in inner diameter toward the tip, and a second tapered portion having an inner diameter that expands toward the tip from the tip of the first tapered portion to allow insertion of a male connector, wherein the length of the first tapered portion is longer than the length of the second tapered portion, the taper angle of the first tapered portion is greater than the taper angle of the second tapered portion, and the inner diameter of the base end of the first tapered portion is greater than the inner diameter of the tip of the second tapered portion.

[0007] In one embodiment of an enteral nutrition syringe, a first tapered section and a second tapered section are integrally formed in the nozzle. Compared to a case where the first and second tapered sections are detachable from each other, the inner surface can be made smoother, improving flowability. Furthermore, the minimum inner diameter of the nozzle is 3.0 mm or more, the length of the first tapered section is longer than the length of the second tapered section, the taper angle of the first tapered section is larger than the taper angle of the second tapered section, and the inner diameter of the base end of the first tapered section is larger than the inner diameter of the tip end of the second tapered section. In this way, a relatively long first tapered section can be formed with a flow path diameter greater than or equal to a predetermined value and a large flow path cross-sectional area, thus suppressing an increase in pressing force.

[0008] In one embodiment of an enteral nutrition syringe, the nozzle can be configured to have a nozzle body having a first tapered portion and a tip member having a second tapered portion welded to the tip of the nozzle body. Alternatively, the nozzle can be configured to have a nozzle body having a first tapered portion and a tip member having a second tapered portion fixed to the tip of the nozzle body via an adhesive layer. In either configuration, a nozzle having a relatively long first tapered portion with a flow path diameter greater than or equal to a predetermined value and a large flow path cross-sectional area can be easily realized.

[0009] In one embodiment of an enteral nutrition syringe, the ratio of the inner diameter of the base end of the first tapered section to the inner diameter of the tip end of the second tapered section can be 1.5 or more and 1.9 or less. This configuration allows for a nozzle with a diameter that is easy to operate while suppressing an increase in pressing force.

[0010] In one embodiment of an enteral nutrition syringe, the ratio of the length of the first tapered section to the length of the second tapered section can be between 2 and 10. This configuration allows for a nozzle of an easily operable length while suppressing an increase in pressing force. [Effects of the Invention]

[0011] The enteral nutrition syringe of this disclosure can be connected to a male connector for enteral nutrition, and the force required to push out the contents can be reduced, improving operability. [Brief explanation of the drawing]

[0012] [Figure 1] This is a side view showing the barrel of a syringe according to one embodiment. [Figure 2] This is a cross-sectional view showing the barrel of a syringe according to one embodiment. [Figure 3] This is a cross-sectional view showing the tip component of the nozzle. [Figure 4] This is a cross-sectional view showing a nozzle according to a modified example. [Figure 5] Figures (a) to (c) show the simulation results of the pressure distribution inside the barrel. [Modes for carrying out the invention]

[0013] As shown in Figures 1 to 3, an enteral nutrition syringe according to one embodiment has a barrel 100 and a plunger (not shown). The barrel 100 has a cylindrical portion 101, a tip surface 112 that closes the tip of the cylindrical portion 101, and a nozzle 102 that protrudes toward the tip from the tip surface 112. A plunger having a gasket can be inserted from the base end of the barrel 100 to push out the contents of the barrel 100 from the nozzle 102.

[0014] The nozzle 102 has a first tapered section 102a that gradually decreases in diameter towards the tip, and a second tapered section 102b that expands in diameter from the tip of the first tapered section 102a towards the tip. The inner diameter, taper angle, and length of the second tapered section 102b are set so that a male connector for enteral nutrition can be inserted and connected from the tip side. Near the tip of the second tapered section 102b, there is an external thread 133 into which the coupler of the male connector can be screwed.

[0015] In this embodiment, the length D1 of the first tapered portion 102a is longer than the length D2 of the second tapered portion 102b, the taper angle of the first tapered portion 102a is greater than the taper angle of the second tapered portion 102b, and the inner diameter φ1 at the base end of the first tapered portion 102a is greater than the inner diameter φ2 at the tip of the second tapered portion 102b. Furthermore, the minimum inner diameter of the nozzle 102, which is the combined length of the first tapered portion 102a and the second tapered portion 102b, is preferably greater than the inner diameter of a commercially available new standard nozzle, and is 3.0 mm or more, preferably 3.5 mm or more. This relationship between the first tapered portion 102a and the second tapered portion 102b allows the first tapered portion 102a to have a relatively long shape with a large flow path cross-sectional area. This makes it possible to reduce the pressing force when pushing out the contents of the barrel 100 with the plunger. Furthermore, the force required to aspirate enteral nutritional fluid can also be reduced.

[0016] In addition, by forming the first tapered portion 102a, the position of the tip of the nozzle 102 can be separated from the distal end surface 112 of the cylindrical portion 101, and thus the advantage that the operation of sucking the enteral nutrient solution into the syringe becomes easier can be obtained. Since the syringe for enteral nutrition is also used at home, the operability is very important.

[0017] Furthermore, by making the nozzle 102 in which the first tapered portion 102a and the second tapered portion 102b are integrally formed, compared with the case where the first tapered portion 102a and the second tapered portion 102b are non-integrally (detachable from each other), no unintentional gaps due to connection failures or deformations occur in the vicinity of the first tapered portion 102a and the second tapered portion 102b, so the inner surface can be made smoother and the fluidity can be improved. Also, if the first tapered portion 102a and the second tapered portion 102b are configured to be continuously and smoothly connected, it is possible to make it difficult for the enteral nutrient solution to stay in the nozzle 102. Also, it becomes difficult for the enteral solution to remain after use, and cleaning becomes easier. In home care, since the syringe for enteral nutrition is washed and reused repeatedly, the ability to be easily cleaned is important.

[0018] When no step is generated between the first tapered portion 102a and the second tapered portion 102b, the inner diameter at the tip of the first tapered portion 102a and the inner diameter at the base end of the second tapered portion 102b are the minimum of the inner diameter of the nozzle 102. From the viewpoint of reducing the pressing force, the minimum value of the inner diameter of the nozzle 102 is 3.0 mm or more, preferably 3.5 mm or more. Since the inner diameter φ2 and the taper angle at the tip of the second tapered portion 102b are determined by the standard, they cannot be freely changed.

[0019] The ratio (D2 / D1) of the length D1 of the first tapered portion 102a to the length D2 of the second tapered portion 102b is preferably 2 or more, more preferably 4 or more, from the viewpoint of the operability during suction, and preferably 10 or less from the viewpoint of the strength of the nozzle 102. FIGS. 1 and 2 show an example where D2 / D1 is about 6.7.

[0020] The ratio (φ1 / φ2) of the inner diameter φ1 at the proximal end of the first tapered portion 102a to the inner diameter φ2 at the distal end of the second tapered portion 102b is preferably 1.5 or more from the viewpoint of increasing the flow path cross-sectional area of the first tapered portion 102a, and is preferably 1.9 or less from the viewpoint of suppressing the thickness of the nozzle 102 and ensuring operability. The inner diameter φ1 at the proximal end of the first tapered portion 102a is the inner diameter at the most proximal position when it is assumed that the entire first tapered portion 102a extends to the most proximal position when the distal end surface 112 of the barrel 101 is an inclined surface.

[0021] In the present embodiment, the taper angle of the second tapered portion 102b is 6 / 100 according to the standard of the male connector to be inserted. The taper angle of the first tapered portion 102a is larger than the taper angle of the second tapered portion 102b. In this case, if the length D1 of the first tapered portion 102a is made longer than the length D2 of the second tapered portion 102b, the inner diameter φ1 at the proximal end of the first tapered portion 102a can be made larger than the inner diameter φ2 at the distal end of the second tapered portion 102b. In the present embodiment, the taper angle of the first tapered portion 102a is 125 / 1000.

[0022] The barrel 100 of the present embodiment in which the nozzle 102 has the first tapered portion 102a and the second tapered portion 102b can be formed by integrally molding the nozzle main body portion 120 that becomes the first tapered portion 102a with the cylindrical portion 101 and then fixing the tip member that becomes the second tapered portion 102b to the tip of the nozzle main body portion 120.

[0023] The tip member can take various shapes. For example, the tip member 130 shown in FIG. 3 is cylindrical and has a connector portion 131 on the tip side and a connecting portion 132 on the proximal side. External threads 133 are formed on the outer surface of the connector portion 13 to which the coupler of the male connector can be screwed.

[0024] The connector portion 131 is the portion that becomes the second tapered portion 102b, and has a connector portion tapered surface 134 that gradually widens in diameter toward the base end, and a chamfered portion 135 formed at the base end of the connector portion tapered surface 134. The tip side of the chamfered portion 135 is a tapered surface 135a that has a greater inclination than the connector portion tapered surface 134. The connecting portion 132 has a connecting portion tapered surface 137 that gradually narrows in diameter toward the tip, and a connecting portion tip surface 135b formed at the tip of the connecting portion tapered surface 137 that protrudes radially inward and is a vertical surface that is almost perpendicular to the central axis of the tip member 130. The connecting portion tip surface 135b is the base end side surface of the chamfered portion 135.

[0025] The tapered surface 137 of the connecting portion has a tapered shape that substantially coincides with the outer surface of the first tapered portion 102a, and the connecting portion 132 can be fitted onto the nozzle body portion 120. The tip surface 135b of the connecting portion has a protrusion 136 that partially protrudes toward the base end, so when the nozzle body portion 120 is inserted into the connecting portion 132, the tip surface of the nozzle body portion 120 comes into contact with the protrusion 136. When ultrasonic welding is performed in this state, the protrusion 136 melts, and the tip member 130 is irremovably fixed to the tip of the nozzle body portion 120. As a result, the first tapered portion and the second tapered portion are integrally formed in the nozzle portion. As the protrusion 136 melts, the tip surface of the nozzle body portion 120 comes into contact with the tip surface 135b of the connecting portion and adheres tightly to it. Furthermore, since the minimum inner diameter φ3 of the chamfered portion 135 and the inner diameter of the tip of the nozzle body portion 120 coincide within the range of molding tolerance, the inner surface of the nozzle body portion 120 and the tapered surface 135a of the chamfered portion 135 are smoothly connected with virtually no step. As a result, a nozzle 102 is formed with virtually no step on the inner surface from the base to the tip, making it easy to clean the inside of the nozzle.

[0026] By forming the protrusion 136, the tip surface of the nozzle body 120 and the tip surface 135b of the connecting part can be welded more firmly. The shape of the protrusion 136 is not particularly limited. The protrusion 136 can be formed as needed, and flat surfaces can be welded together. It can also be welded together slanted surfaces or surfaces with complementary irregularities.

[0027] When welding the tip surface of the nozzle body 120 to the tip surface 135b of the connecting portion, the space between the outer surface of the nozzle body 120 and the tapered surface 137 of the connecting portion is basically not welded. While it is possible to have almost no clearance between the outer surface of the nozzle body 120 and the tapered surface 137 of the connecting portion, it is possible to slightly increase the clearance or slightly change the taper angles of each to create a small gap between the outer surface of the nozzle body 120 and the tapered surface 137 of the connecting portion. With this configuration, the molten resin can be guided into the gap, making it less likely to flow out into the inside of the nozzle. The gap for guiding the molten resin can also be created only near the tip of the nozzle body 120. In this embodiment, the inner diameter of the tapered surface 137 of the connecting portion is made smaller than the outer diameter of the nozzle body 120 to create a gap, and a gap is partially formed even after welding.

[0028] Figure 3 shows a configuration in which the tip surface of the nozzle body 120 and the tip surface 135b of the connecting part are welded together. However, it is also possible to weld the outer surface of the nozzle body 120 and the tapered surface 137 of the connecting part. In this case, the taper angle of the connecting part 132 can be made slightly larger than the taper angle of the nozzle body 120 so that the gap between the outer surface of the nozzle body 120 and the tapered surface 137 of the connecting part becomes larger towards the base end. In this way, the molten resin produced during welding can be guided towards the base end, making it less likely to flow out into the inside of the nozzle.

[0029] When welding the tip surface of the nozzle body 120 to the tip surface 135b of the connecting portion, ultrasonic welding is preferred because it allows for easy control of the melting position. When welding the outer surface of the nozzle body 120 to the tapered surface 137 of the connecting portion, methods other than ultrasonic welding, such as high-frequency welding and heat welding, can be used.

[0030] As shown in Figure 4, a second tapered portion 102b can also be formed by a tip member 130A that is bonded to the nozzle body portion 120, which forms the first tapered portion 102a. The tip member 130A has a connecting portion 132A formed on the base end side of the connector portion 131. When the nozzle body portion 120, which has adhesive applied to its outer surface, is inserted into the connecting portion 132A, the outer surface of the nozzle body portion 120 and the inner surface of the connecting portion 132A are bonded together by the adhesive layer 151, and the tip member 130A is irremovably fixed to the tip of the nozzle body portion 120. As a result, the first tapered portion 102a and the second tapered portion 102b are integrally formed in the nozzle 102.

[0031] Since the tip member 130A does not have a protrusion that projects toward the base end on the connecting tip surface 135b, the tip surface of the nozzle body 120 comes into direct contact with the connecting tip surface 135b. Although not shown in the figure, adhesive can be applied and bonded between the connecting tip surface 135b and the tip surface of the nozzle body 120. By adjusting the amount of adhesive applied, it is possible to prevent the adhesive from overflowing into the inside of the nozzle body 120. In this way, the inner surface of the nozzle body 120 and the tapered surface 135a of the chamfered portion 135 can be connected smoothly with virtually no step. In this modified example, the tip surface of the nozzle body 120 and the connecting tip surface 135b are vertical surfaces, but they can also be surfaces with complementary shapes.

[0032] Figure 4 shows an example where, from the viewpoint of adhesive strength, the length of the connecting portion 132A fixed with adhesive is longer than the connecting portion 132 fixed by ultrasonic welding, and also longer than the connector portion 131. However, the length of the connecting portion can be optimized by considering the fixing method and conditions, etc.

[0033] In Figures 3 and 4, the tip member is fitted onto the nozzle body. By fitting it onto the nozzle body, the inner diameter of the flow path can be increased, making it easy to connect the nozzle without any steps. In particular, when fixing with adhesive, an adhesive layer is formed on the outside of the nozzle body, so contact between the nutrient solution and the adhesive layer can be avoided. However, it is also possible to configure the nozzle body so that the tip member is fitted onto the inside.

[0034] The method for fixing the tip member to the tip of the nozzle body is not limited to the example provided, and various other methods can be employed. Furthermore, instead of fixing a separately molded tip member to the nozzle body, a nozzle 102 having a first tapered portion 102a and a second tapered portion 102b can also be integrally molded to realize a nozzle portion in which the first tapered portion and the second tapered portion are integrally formed. Such a nozzle portion may be connected or joined to a separately molded cylindrical portion, or the nozzle and cylindrical portion may be integrally molded together.

[0035] The nozzle 102 is formed offset from the central axis of the cylindrical portion 101 of the barrel 100, which has the advantage of improving operability, such as the aspiration of enteral nutritional fluid. However, the nozzle 102 can also be configured to protrude from the center of the cylindrical portion 101. By making the tip surface 112 of the barrel 100 a conical surface that is convex toward the tip, the contents of the barrel 100 can be easily pushed out by the plunger, and the amount of liquid remaining can be reduced. The apex angle of the tip surface 112 is preferably about 150°. However, the tip surface 112 can also be a surface perpendicular to the central axis of the cylindrical portion of the barrel 100.

[0036] In this embodiment, a flange 113 is formed at the base end of the cylindrical portion 101 of the barrel 100. By forming the flange 113, a finger can be placed on it when operating the plunger, thus improving operability. However, the flange 113 may be formed only if necessary, and may not be formed at all.

[0037] For three types of barrels with different nozzle shapes, the pressure loss, load on the base of the barrel, and pressure distribution within the barrel were determined by simulation when fluid was introduced at a constant velocity from the base of the barrel. Larger pressure loss and load indicate a greater pressing force when pushing out enteral nutrition fluid. Figures 6(a) to 6(c) show the pressure distribution within each barrel. In Figures 6(a) to 6(c), darker colors indicate lower pressure, and lighter colors indicate higher pressure. The fluid flow velocity was set to 100 mL / min. The fluid density was 1100 kg / m³. 3 The fluid was assumed to be a Newtonian fluid with a viscosity coefficient of 20 Pa·s. The analysis software used was STAR-CCM+. The barrel section had a diameter of 29.1 mm and a length of 105.11 mm in all cases, with only the nozzle section having a different shape.

[0038] The pressure loss in the barrel of this embodiment was 337 mmHg, and the load was 29.8 N. In the case of the barrel of this embodiment, as shown in Figure 6(a), there were no light-colored areas throughout the barrel, and 4.5 × 10 4 A pressure below Pa is maintained. The nozzle shape used in the simulation was as follows: the inner diameter φ1 at the base of the first tapered section was 9.77 mm, the inner diameter φ3 at the tip of the first tapered section (= base of the second tapered section) was 4.4 mm, the inner diameter φ2 at the tip of the second tapered section was 5.69 mm, the length D1 of the first tapered section was 42.94 mm, and the length D2 of the second tapered section was 5.9 mm.

[0039] In the case of a barrel with a nozzle of comparative shape 1 that does not have the first tapered section, the pressure loss was 510 mmHg and the load was 45.2 N, both of which were greater than the pressure loss and load of the barrel in this embodiment. Also, as shown in Figure 6(b), the pressure from inside the cylinder to the base end of the nozzle was 4.5 × 10 4Lighter colored areas exceeding Pa are present. Pressure unevenness is also occurring at the nozzle connection point. Comparative shape 1 is a standard nozzle shape that meets the new ISO standard, with the base end 1.45 mm of the nozzle being a small diameter section with an inner diameter of 2.9 mm, and the tip end 7.14 mm being a 6 / 100 tapered section, connected by a transition section with a length of 1.18 mm.

[0040] In the case of a barrel with a nozzle of comparative shape 2, which has a straight tube with a constant inner diameter instead of the first tapered section, the pressure loss was 550 mmHg and the load was 48.8 N, which were greater than those of the barrel of comparative shape 1. Furthermore, as shown in Figure 6(c), the pressure from inside the cylinder to the base end of the nozzle was even higher than that of comparative shape 1, and pressure unevenness occurred at the nozzle connection point. The nozzle of comparative shape 2 has a straight tube section with an inner diameter of 5.34 mm instead of the first tapered section. The length of the straight tube section was set to 42.41 mm.

[0041] Table 1 summarizes the simulation results for the barrel of this embodiment and the barrels of each comparative shape. In the case of the nozzle of this embodiment, the increase in pressure loss and load can be kept small, and the overall pressure inside the barrel can be kept low. On the other hand, in the case of comparative shape 1, in which the second tapered section, which is the connector, is directly connected to the cylindrical section via the small diameter section, and comparative shape 2, in which it is connected via the straight pipe section, both the pressure loss and load increased significantly. In addition, the pressure from inside the cylindrical section to the base end of the nozzle increased.

[0042] [Table 1] [Industrial applicability]

[0043] The syringe of this disclosure is connectable to a male connector for enteral nutrition and requires little pressing force to expel its contents, making it useful in medical fields such as enteral nutrition. [Explanation of Symbols]

[0044] 100 barrels 101 Cylinder part 102 Nozzles 102a First tapered section 102b Second tapered section 112 Tip surface 113 Flange 120 Nozzle body 130 Tip component 130A Tip component 131 Connector section 132 Connecting part 132A Connection part 134 Tapered surface of connector 135 Chamfered part 135a Slope 135b Connecting part end surface 136 Convex part 137 Tapered surface of connecting section 151 Adhesive layer

Claims

1. It has a cylindrical barrel with a nozzle at the tip into which a male connector can be inserted, The nozzle integrally comprises a first tapered section having a minimum inner diameter of 3.0 mm or more, in which the inner diameter gradually decreases toward the tip, and a second tapered section in which the inner diameter expands toward the tip of the first tapered section, allowing the male connector to be inserted. The length of the first tapered portion is longer than the length of the second tapered portion. The taper angle of the first tapered portion is greater than the taper angle of the second tapered portion. The inner diameter of the base end of the first tapered portion is larger than the inner diameter of the tip of the second tapered portion. An enteral nutrition syringe in which the ratio of the length of the first tapered portion to the length of the second tapered portion is 2 or more and 10 or less.

2. The enteral nutrition syringe according to claim 1, wherein the nozzle comprises a nozzle body having a first tapered portion and a tip member having a second tapered portion welded to the tip of the nozzle body.

3. The enteral nutrition syringe according to claim 1, wherein the nozzle comprises a nozzle body having a first tapered portion and a tip member having a second tapered portion fixed to the tip of the nozzle body via an adhesive layer.

4. The enteral nutrition syringe according to any one of claims 1 to 3, wherein the ratio of the inner diameter of the base end of the first tapered portion to the inner diameter of the tip of the second tapered portion is 1.5 or more and 1.9 or less.

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