Injection system, syringe, and gasket

Abstract

To directly connect a gasket with a ram when the ram is connected with the gasket.SOLUTION: An injection system 1 has: a gasket 100 having a plurality of engaging claws 122, wherein each of the engaging claws includes an inner surface S1 which defines a hole H having an inlet with an enlarged diameter and an outer surface S2 inclined in a direction away from a perpendicular line P passing through a center of the hole H, and the engaging claws 122 are to be displaced between a widened position and a narrowed position; a ram 110 to be inserted into the hole H so as to engage with the engaging claws 122; a cylinder 91, into which the gasket 100 is to be inserted, contacting the outer surfaces S2 of the engaging claws 122 of the inserted gasket 100; and an injection device 2 configured to move the ram 110 forward and injecting a chemical solution in the cylinder 91, wherein an annular groove 125 which serves as a starting point of deformation of the engaging claws 122 is formed on the gasket 100.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a syringe filled with a medicinal liquid, a gasket for the syringe, and an injection system in which the syringe is mounted. [Background technology]

[0002] Conventionally, as a ram and a gasket used in a syringe for injecting a liquid medicine, for example, Patent Document 1 describes a plunger having an expandable and contractible portion and a syringe having a first inner diameter and a second inner diameter smaller than the first inner diameter. The terminal portion of the plunger shaft is inserted into the space of the plunger. When the plunger advances within the syringe until it reaches the second inner diameter, the expandable and contractible portion contracts. This causes the tab of the plunger (gasket) to engage with the groove of the plunger shaft (ram). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-111185 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the tab of the gasket engages with a groove in the ram, but the inner dimension of the groove is set larger than the outer dimension of the tab to make it easier for the tab to enter the groove. Furthermore, due to manufacturing tolerances, a gap may form between the tab and the groove. This can cause the ram to rattle relative to the gasket, resulting in abnormal noise. Furthermore, if the central axis of the ram is tilted relative to the gasket, a pressing force is applied to the syringe via the gasket in the tilted direction. In this case, the syringe may become detached from the injection device when injecting a drug solution at high pressure. [Means for solving the problem]

[0005] In order to solve the above problem, one example of an injection system of the present invention comprises a gasket having a plurality of engaging claws including an inner surface that defines a hole with an enlarged entrance and an outer surface that slopes away from a perpendicular line passing through the center of the hole, the engaging claws being displaceable between an enlarged position and a narrowed position, a ram that is inserted into the hole to engage with the engaging claws, a cylinder into which the gasket is inserted, the cylinder abutting the outer surfaces of the engaging claws of the gasket after insertion, and an injection device configured to advance the ram and inject a chemical solution into the cylinder, wherein the gasket has an annular groove formed therein that serves as a starting point for deformation of the engaging claws.

[0006] Another example of a syringe according to the present invention comprises a gasket having a plurality of engaging claws that have an inner surface defining a hole with an enlarged entrance and an outer surface that slopes away from a perpendicular line passing through the center of the hole, the engaging claws displacing between an enlarged position and a narrowed position, and a cylinder into which the gasket is inserted that abuts against the outer surfaces of the engaging claws of the gasket after insertion, the gasket having an annular groove formed therein that serves as a starting point for deformation of the engaging claws.

[0007] Another example of a gasket of the present invention is a gasket having a plurality of engaging claws including an inner surface defining a hole with an enlarged entrance and an outer surface inclined away from a perpendicular line passing through the center of the hole, the engaging claws being displaceable between an enlarged position and a narrowed position, and having an annular groove formed as a starting point for deformation of the engaging claws.

[0008] Further features of the invention will become apparent from the following description of embodiments thereof, given by way of example with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic top view of an injection head. [Figure 2] 1 is a schematic exploded perspective view of a syringe according to a first embodiment of the present invention. [Figure 3]FIG. 2 is a schematic perspective view of a gasket. [Figure 4] FIG. 10 is a schematic cross-sectional view illustrating the connection of the ram and the gasket. [Figure 5] FIG. 10 is a schematic cross-sectional view illustrating the connection of the ram and the gasket. [Figure 6] FIG. [Figure 7] FIG. 10 is a schematic cross-sectional view illustrating the connection of the ram and the gasket. [Figure 8] FIG. 10 is a schematic cross-sectional view illustrating the connection of the ram and the gasket. [Figure 9] FIG. 4 is a schematic cross-sectional view of a syringe according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a schematic rear view of a gasket according to a third embodiment of the present invention. [Figure 11] FIG. 10 is a schematic rear view of a syringe according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of components described in the following embodiments are arbitrary and can be changed depending on the configuration of the device to which the present invention is applied or various conditions. Furthermore, unless otherwise specified, the scope of the present invention is not limited to the embodiments specifically described below. In the following description, the front side ("front") corresponds to the tip end side of the syringe, and the opposite side corresponds to the rear side ("rear").

[0011] [Example] FIG. 1 is a schematic perspective view of an injection system 1 for injecting a medicinal liquid. As shown in FIG. 1, the injection system 1 is configured to advance a ram 110 and includes an injection head 2 (injection device) that injects the medicinal liquid in a cylinder 91 of a syringe 90 (FIG. 2). The injection system 1 also includes an adapter 8 for mounting the syringe 90 on the injection head 2. The adapter 8 is attached to a holder of the injection head 2. The injection head 2 includes a pressing part 4 that presses a gasket 100 (FIG. 2) inserted into the syringe 90.

[0012] The pressing unit 4 is controlled by a control unit (not shown) to advance by pressing against a gasket 100 inside the syringe 90 in order to dispense the medicinal liquid inside the syringe 90. The pressing unit 4 also includes a ram 110 connected to a drive mechanism (not shown). Specifically, the control unit controls the motor inside the injection head 2 so that the ram 110 advances when the motor rotates forward and moves backward when the motor rotates reversely. The injection head 2 also includes a reading unit 21 that reads a data carrier, such as an RFID or barcode, provided on the syringe 90 mounted on the adapter 8.

[0013] The injection system 1 is also connected to an imaging device (not shown) by wire or wirelessly. When injecting a medicinal solution and capturing images, various data is transmitted and received between the imaging device and the injection system 1. Examples of such imaging devices include an MRI (Magnetic Resonance Imaging) device, a CT (Computed Tomography) device, an angio imaging device, a PET (Positron Emission Tomography) device, a SPECT (Single Photon Emission Computed Tomography) device, a CT angio device, an MR angio device, an ultrasound diagnostic device, and a vascular imaging device.

[0014] Furthermore, injection system 1 includes a console with a touch panel as a display unit that displays the injection status of the medicinal liquid, and a control device with a control unit and power supply (neither of which are shown). This console and injection head 2 can be connected to each other via wire or wireless. Furthermore, a remote control device such as a hand switch may be connected to the console via wire or wireless. This remote control device can also be used to start or stop the injection of the medicinal liquid. Note that injection head 2 and the control device can be integrated into a caster stand (not shown). Alternatively, injection head 2 and the control device can be provided separately and mounted on a caster stand.

[0015] The control device stores data on operation patterns (infusion protocols) and data on medicinal liquids in advance. When injecting medicinal liquids into a patient, an operator operates the touch panel of the console to input the patient's physical data, such as the injection rate, injection amount, injection time, weight, height, body surface area, heart rate, and cardiac output, as well as data on the type of medicinal liquid. The control device then calculates optimal injection conditions based on the input data and pre-stored data. The control device then determines the amount of medicinal liquid to be injected into the patient and the injection protocol based on the calculated injection conditions.

[0016] Furthermore, once the control device has determined the amount of medicinal liquid and the injection protocol, it displays the specified data or graph on the touch panel of the console or the head display of the injection head 2. This allows the operator to check the displayed data or graph. Data on the operation pattern (injection protocol) and data on the medicinal liquid can also be input from an external storage medium.

[0017] To inject a medicinal liquid, the operator turns on the power of the injection head 2 and loads the syringe 90 into the injection head 2. The operator then presses the injection button displayed on the touch panel. Alternatively, if the injection head 2 is equipped with an operation panel, the operator can also press the injection button on the operation panel. Furthermore, the operator can also start injection by pressing a button on a hand switch. Alternatively, the operator may turn on the power of the injection head 2 after loading the syringe 90.

[0018] When the injection button is pressed, the control unit sends a forward rotation signal to the motor as a drive voltage. In response to this forward rotation signal, the motor shaft rotates forward, and the pressing unit 4 (ram 110) moves forward. After that, when the injection is completed and the syringe 90 is removed, the control unit sends a reverse rotation signal to the motor as a drive voltage to move the ram 110 backward. In response to this reverse rotation signal, the motor shaft rotates reversely, and the ram 110 moves backward.

[0019] The pressing unit 4 has a drive mechanism (not shown). This drive mechanism includes a transmission mechanism connected to the motor shaft, a ball screw shaft connected to the transmission mechanism, a ball screw nut attached to the ball screw shaft, and an actuator connected to the ball screw nut. The transmission mechanism also includes a pinion gear connected to the shaft and a screw gear connected to the ball screw shaft. The transmission mechanism transmits rotation from the motor to the ball screw shaft. Therefore, the rotation of the motor shaft is transmitted to the ball screw shaft via the pinion gear and the screw gear. As a result, the ball screw shaft rotates in accordance with the transmitted rotation. The ball screw nut slides forward or backward in response to the rotation of the ball screw shaft. The ram 110 of the pressing unit 4 moves forward or backward in response to this sliding of the ball screw nut.

[0020] [First embodiment] 2 is a schematic exploded perspective view of a syringe 90 according to the first embodiment, showing the syringe 90 as seen from above the front side. As shown in FIG. 2, the syringe 90 has a gasket 100 that is slidable within a cylinder 91. The gasket 100 is inserted into the cylinder 91 and abuts against an outer surface S2 (FIG. 4) of the inserted gasket 100. The cylinder 91 also has a flange 92 that is attached to a groove in the adapter 8. The gasket 100 also has an absorber 120, an O-ring 130, and a sealing member 140.

[0021] The plunger 120 has a substantially disk-shaped insertion portion 121 and a plurality of divided engaging claws 122. The insertion portion 121 has a plurality of intersecting ribs. An annular groove 125 is formed between the insertion portion 121 and the engaging claws 122. The seal member 140 has an annular protrusion formed on its outer surface. The annular protrusion abuts against the inner surface of the cylinder 91 to seal the cylinder 91. Although three annular protrusions are formed in FIG. 2, two, one, or four or more annular protrusions may be formed. A space for accommodating the insertion portion 121 is formed in the seal member 140, and the rear end of the seal member 140 protrudes into the space. The engaging claw 122 has a protrusion 124 (FIG. 3) that engages with the engaging groove 112 formed in the front end 111 of the ram 110.

[0022] When assembling the gasket 100, first, the O-ring 130 is fitted into the insertion portion 121 side of the plunger 120, and the O-ring 130 is attached to the groove 123 formed in the engagement claw 122. Next, the insertion portion 121 is inserted into the space within the seal member 140, and the seal member 140 is attached to the plunger 120. At this time, the rear end of the seal member 140 fits into the annular groove formed behind the insertion portion 121. This secures the seal member 140 to the plunger 120. The attached O-ring 130 prevents the engagement claws 122 from widening. This makes it possible to make the gaps between adjacent engagement claws 122 uniform, and therefore makes it possible to keep the distances between the protrusions 124 of the engagement claws 122 constant.

[0023] In this manner, the gasket 100 is assembled. The plunger 120 is made of an elastic resin such as POM (polyacetal resin) and can be manufactured by molding. The seal member 140 is made of, for example, butyl rubber and can be manufactured by molding. The ram 110 is made of, for example, stainless steel or aluminum and can be manufactured by welding a solid, substantially cylindrical front end portion 111 to a hollow pipe. Alternatively, the ram 110 may be manufactured by screwing the solid front end portion 111 into a hollow pipe. Alternatively, the front end portion 111 may be manufactured using a material other than stainless steel or aluminum that is harder than the gasket 100.

[0024] When the motor rotates forward with the engaging claws 122 of the gasket 100 connected to the front end 111 of the ram 110, the pressing unit 4 pushes the ram 110 forward. Then, as the ram 110 and the gasket 100 move forward, the medicinal solution in the cylinder 91 is forced out through the tip 93. As a result, the medicinal solution is injected into the patient's body via an extension tube or the like connected to the tip 93. After the medicinal solution is injected, when the motor rotates in the reverse direction, the pressing unit 4 pulls the ram 110 in the backward direction, causing the gasket 100 to move backward.

[0025] As shown in Figure 2, the corners continuous with the end face of the front end 111 are chamfered. This prevents the corners from coming into contact with the protrusion 124 when the ram 110 is inserted. The corners of the engagement groove 112 of the front end 111 are also chamfered and rounded. This prevents the protrusion 124 from being scraped when the protrusion 124 engages with or disengages from the engagement groove 112.

[0026] Fig. 3 is a schematic perspective view of the gasket 100 as seen from behind, with the O-ring 130 omitted for ease of explanation. As shown in Fig. 3, the intake 120 has a plurality of engaging claws 122 each having a substantially sector-shaped cross section. The number of engaging claws 122 may be two or more and is not limited to six. Furthermore, gaps are formed between adjacent engaging claws 122, and when the gasket 100 is inserted into the cylinder 91, the adjacent engaging claws 122 are displaced so as to move closer to each other.

[0027] Each engagement claw 122 has a groove 123 into which an O-ring 130 is fitted and a protrusion 124 that engages with the engagement groove 112 of the ram 110. The tip of the protrusion 124 is rounded to facilitate insertion into the engagement groove 112 of the ram 110. Note that in FIG. 3, reference symbols are assigned to the groove 123 and protrusion 124 of only one engagement claw 122. However, grooves 123 and protrusions 124 are provided on all six engagement claws 122. All engagement claws 122 are formed to be the same size, and the gaps between the engagement claws 122 are also the same length. This prevents the position of each engagement claw 122 relative to the ram 110 from changing during displacement. In other words, as the gasket 100 is inserted, each engagement claw 122 is displaced by the same distance.

[0028] An annular groove 125 is formed in the intake 120 between the insertion portion 121 and the engaging pawl 122. The engaging pawl 122 is connected to the insertion portion 121 at the portion where the annular groove 125 is formed. In order to facilitate the displacement (deformation) of the engaging pawl 122, the portion where the annular groove 125 is formed is thinner than the portion where the protrusion 124 is formed. In addition, a hole H (FIG. 4) surrounded by the protrusion 124 is formed in the intake 120, and the ram 110 is inserted into the hole H so as to engage with the engaging pawl 122.

[0029] [Connection between Ram 110 and Gasket 100] The connection between the ram 110 and the gasket 100 will be described with reference to Figures 4 to 8. Figure 4 is a schematic cross-sectional view of the syringe 90 before the ram 110 is inserted into the hole H of the plunger 120. Figure 5 is a schematic cross-sectional view of the syringe 90 after the ram 110 has been inserted into the hole H of the plunger 120. Figure 6 is a schematic enlarged view of the circled portion in Figure 5. Figure 7 is a schematic cross-sectional view of the syringe 90 after the ram 110 and the gasket 100 have been connected. Figure 8 is a schematic cross-sectional view of the syringe 90 after the ram 110 has advanced the gasket 100. Figures 4 to 8 also show cross sections along the longitudinal direction passing through the central axis of the cylinder 91.

[0030] As shown in FIG. 4, the gasket 100 has a hole H with an enlarged entrance. That is, the entrance of the hole H, through which the ram 110 is inserted, has a larger inner diameter than the bottom, against which the end face of the ram 110 presses. The gasket 100 also has an engagement pawl 122 that moves between an enlarged position (FIG. 5) and a narrowed position (FIG. 7). The engagement pawl 122 includes an inner surface S1 including a first inner surface 126 and a second inner surface 127 that define the hole H, and an outer surface S2 that slopes away from a perpendicular line P passing through the center of the hole H (bottom). The first inner surface 126 extends in a ring shape from the bottom of the hole H of the plunger 120, against which the end face of the front end 111 of the ram 110 abuts. The first inner surface 126 also extends parallel to the perpendicular line P. The second inner surface 127 extends in a ring shape from the first inner surface 126 to the protrusion 124. Furthermore, the second inner surface 127 is inclined relative to the first inner surface 126 in a direction away from the perpendicular line P as it approaches the entrance of the hole H.

[0031] The outer surface S2 of the engagement claws 122 is inclined away from the perpendicular line P extending in the extension direction of the hole H as it approaches the entrance of the hole H. Therefore, the length of the line segment that intersects with the perpendicular line P and connects the outer edges of the multiple engagement claws 122 is longer than the length of the inner diameter of the cylinder 91. In other words, the outer edges of the engagement claws 122 are located outside the inner surface of the cylinder 91. Furthermore, the engagement claws 122 have protrusions 124 that protrude toward the perpendicular line P. The ram 110 has an annular engagement groove 112 with which the protrusions 124 are engaged. However, if the protrusions 124 of the engagement claws 122 displaced to the narrowed position are not arranged annularly, the engagement groove 112 may be formed at a position corresponding to the protrusions 124.

[0032] At the front end 111 of the ram 110, the outer surface of the portion closer to the end face than the engagement groove 112 is also slightly inclined with respect to the central axis R of the ram 110. The angle of inclination of this outer surface with respect to the central axis R (for example, 1 to 5 degrees) is set to be smaller than the angle of inclination of the second inner surface 127 with respect to the perpendicular line P (for example, 4 to 10 degrees). Because the outer surface of the front end 111 is inclined, the front end 111 can be guided into the hole H so that the central axis R is aligned with the perpendicular line P when the front end 111 is inserted.

[0033] As shown in Figure 5, when the ram 110 is inserted into the hole H, the end face of the front end 111 abuts against the bottom of the hole H. At this time, the engagement pawls 122 are in a spread position, and the outer surface of the front end 111 abuts against a boundary portion B (Figure 6) between the first inner surface 126 and the second inner surface 127 of the engagement pawls 122. In other words, the inner dimensions of the hole H of the intake suction cup 120 are set so that the boundary portion B abuts against the outer surface of the front end 111. Below, the boundary portion B will be described with reference to Figure 6.

[0034] As shown in FIG. 6 , an annular groove 125, which is the starting point for deformation of the engagement claw 122, is formed at a position corresponding to a boundary portion B between the first inner surface 126 and the second inner surface 127 of the gasket 100. This annular groove 125 has a substantially semicircular cross section. The boundary portion B is located at a position corresponding to the center of the bottom of the annular groove 125. That is, the center of the bottom of the annular groove 125 and the boundary portion B are located within the same cross section perpendicular to the longitudinal direction. As a result, the inner surface S1 of the engagement claw 122 is inclined with the boundary portion B as a boundary. Therefore, when the front end portion 111 is inserted, a gap is generated between the outer surface of the front end portion 111 and the second inner surface 127. Furthermore, because the outer surface of the front end portion 111 is also slightly inclined, a gap is also generated between the outer surface and the first inner surface 126. The annular groove 125 may have a substantially trapezoidal or triangular cross section that narrows inward.

[0035] When the ram 110 pushes the gasket 100, the gasket 100 advances within the cylinder 91. As the gasket 100 advances, the outer surface S2 (FIG. 4) of the engaging claw 122 comes into contact with the inner surface of the cylinder 91 because the outer surface S2 of the engaging claw 122 is inclined. As the gasket 100 advances, the engaging claw 122 is displaced toward the perpendicular line P of the intake 120 due to a reaction force from the inner surface of the cylinder 91. At this time, the engaging claw 122 deforms with the center of the bottom of the annular groove 125 as the starting point. As a result, the boundary portion B is pressed against the front end portion 111.

[0036] That is, boundary portion B is displaced toward the perpendicular line P of the plunger 120. As a result, even if the front end 111 is inserted into the hole H at a position offset from the perpendicular line P, the front end 111 is displaced so that the position of the central axis R of the front end 111 is aligned with the perpendicular line P. That is, the front end 111 is pushed by boundary portion B and displaced toward the center of the hole H. This makes it possible to prevent the central axis R from tilting relative to the gasket 100. Furthermore, even if a gap occurs between the front end 111 and the hole H of the plunger 120 due to manufacturing tolerances or the like, the front end 111 is held at boundary portion B. This makes it possible to prevent the ram 110 from rattling relative to the gasket 100.

[0037] As shown in FIG. 7, when the gasket 100 is inserted into the cylinder 91, the engaging claws 122 contract due to a reaction force from the inner surface of the cylinder 91. Then, the protrusions 124 of the engaging claws 122, which are in the contracted position, enter the engaging grooves 112, and the protrusions 124 engage with the engaging grooves 112. This connects the gasket 100 to the ram 110. Furthermore, as the engaging claws 122 are displaced, the annular groove 125 is deformed to widen. Thereafter, as shown in FIG. 8, when the gasket 100 advances within the cylinder 91, the sealing member 140 presses against the medicinal liquid within the cylinder 91. This causes the medicinal liquid to be forced out of the tip 93 and injected into the patient's body via an extension tube or the like.

[0038] After the injection of the chemical solution, the ram 110 retracts, and the gasket 100 connected to the ram 110 also retracts. When the ram 110 and the gasket 100 retract to the position shown in FIG. 5, the restriction by the inner surface of the cylinder 91 is released. Therefore, the engagement claws 122 spread outward, and the protrusions 124 of the displaced engagement claws 122 disengage from the engagement grooves 112. This disengages the protrusions 124 from the engagement grooves 112. That is, when the ram 110 and the gasket 100 retract until the engagement claws 122 are displaced to the spread position, the protrusions 124 disengage from the engagement grooves 112. Furthermore, as the engagement claws 122 are displaced, the annular groove 125 narrows to return to its original shape. When the ram 110 retracts further, the gasket 100 remains in the position shown in FIG. 5 due to the frictional force between the sealing member 140 and the cylinder 91. As a result, the ram 110 disengages from the gasket 100 and retracts to the pre-insertion position shown in FIG. 4.

[0039] With the ram 110 and gasket 100 according to the first embodiment, the engaging pawls 122 deform from the center of the bottom of the annular groove 125 as a starting point. Therefore, the multiple engaging pawls 122 are displaced uniformly toward the perpendicular line P of the intake suction cup 120. In addition, the front end 111 is held at the boundary portion B. Therefore, the position of the central axis R of the front end 111 of the ram 110 is aligned with the perpendicular line P. This prevents the front end 111 from being positioned offset from the perpendicular line P when the ram 110 is released from the gasket 100. Therefore, the engaging groove 112 of the front end 111 can be prevented from getting caught on the protrusion 124.

[0040] Furthermore, with the ram 110 and gasket 100 according to the first embodiment, rattling of the ram 110 relative to the gasket 100 can be suppressed when the gasket 100 and the ram 110 are connected to each other. Furthermore, because the gasket 100 and the ram 110 are directly connected to each other, the distance between the syringe 90 and the pressing unit 4 can be shortened. This allows the size of the injection head 2 in the injection system 1 to be reduced.

[0041] It should be noted that, instead of the protrusion 124 and the engagement groove 112, an engagement groove may be formed in the engagement claw 122 of the gasket 100, and an annular protrusion may be formed on the front end 111 of the ram 110. Furthermore, if the engagement claw 122 can be manufactured with high precision, the O-ring 130 may be omitted.

[0042] [Second embodiment] In the first embodiment, the engagement claws 122 of the gasket 100 protruded outward from the syringe 90 before insertion. In the second embodiment, the cylinder 291 of the syringe 290 has a skirt portion 295 that covers the engagement claws 222. The second embodiment will be described below with reference to FIG. 9. In the description of the second embodiment, differences from the first embodiment will be described, and the components described in the first embodiment will be given the same reference numbers and their description will be omitted. Unless otherwise specified, components given the same reference numbers perform substantially the same operations and functions, and their effects are also substantially the same.

[0043] Fig. 9 is a schematic cross-sectional view of the syringe 290 before the ram 110 is inserted into the hole H of the plunger 220. Fig. 9 shows a cross section along the longitudinal direction passing through the central axis of the syringe 290. Note that the configuration of the ram 110 is the same as in the first embodiment, and is therefore not shown.

[0044] As shown in FIG. 9 , a skirt portion 295 is formed on the cylinder 291 of the syringe 290 behind the flange 292. The inner surface of this skirt portion 295 is inclined along the outer surface S2 of the engagement claws 222 so that the engagement claws 222 are positioned in the expanded position. Therefore, the inner dimensions of the skirt portion 295 are set to match the outer dimensions of the engagement claws 222 in the expanded state. That is, the skirt portion 295 has a shape that narrows toward the tip 293. As a result, the engagement claws 222 of the gasket 200 inserted inside the skirt portion 295 are not displaced to the narrowed position. Even if the engagement claws 222 are slightly displaced, the gap between the opposing protrusions 224 maintains a state in which the ram 110 can be inserted. In this way, the skirt portion 295 covers the engagement claws 222, thereby preventing foreign matter from adhering to the engagement claws 222.

[0045] Similar to the first embodiment, the gasket 200 of the second embodiment has an inner surface S1 including a first inner surface 226 and a second inner surface 227 that define a hole H with an enlarged entrance, and an annular groove 225 formed at a position corresponding to a boundary portion B between the first inner surface 226 and the second inner surface 227 so as to serve as a starting point for deformation. Meanwhile, the engaging claws 222 of the plunger 220 of the gasket 200 do not have grooves 123 formed therein, nor are O-rings 130 attached thereto. Instead of the O-rings 130, skirt portions 295 are used to prevent the engaging claws 222 from widening. This allows the gaps between adjacent engaging claws 222 to be uniform, and the O-rings 130 can be omitted.

[0046] After the front end 111 of the ram 110 is inserted, the ram 110 pushes the gasket 200 via the front end 111, causing the gasket 200 to advance within the cylinder 291. As the gasket 200 advances, the outer surfaces of the engaging pawls 222 pass through the skirt portion 295 and come into contact with the inner surface of the cylinder 291. As the gasket 200 advances, the engaging pawls 222 are displaced toward the center of the hole H of the intake suction member 220 due to a reaction force from the inner surface of the cylinder 291. At this time, the engaging pawls 222 deform from the center of the bottom of the annular groove 225 as a starting point.

[0047] Then, boundary portion B between first inner surface 226 and second inner surface 227 is pressed against front end portion 111. When gasket 200 is further inserted into cylinder 291, engaging claws 222 receive a reaction force from the inner surface of cylinder 291 and narrow. Then, protrusions 224 of engaging claws 222 displaced to the narrowed position enter engaging grooves 112 of ram 110, and protrusions 224 engage with engaging grooves 112. As a result, gasket 200 is connected to ram 110. Thereafter, as gasket 200 advances within cylinder 291, sealing member 240 presses against the medicinal liquid within cylinder 291. As a result, the medicinal liquid is forced out from tip portion 293 and injected into the patient's body via an extension tube or the like.

[0048] After the chemical solution is injected, the ram 110 retracts, and the gasket 200 connected to the ram 110 also retracts. Then, the ram 110 and the gasket 200 retract to a position where they are no longer restricted by the inner surface of the cylinder 291. This causes the engagement claws 222 to spread outward, and the protrusions 224 disengage from the engagement grooves 112. As a result, the protrusions 224 disengage from the engagement grooves 112. When the ram 110 retracts further, the ram 110 disengages from the gasket 200.

[0049] With the ram 110 and gasket 200 according to the second embodiment, the engaging claws 222 also deform starting from the center of the bottom of the annular groove 225. As a result, the multiple engaging claws 222 are uniformly displaced toward the perpendicular line P of the plunger 220. Furthermore, when the gasket 200 and the ram 110 are connected to each other, rattle of the ram 110 relative to the gasket 200 can be suppressed. Furthermore, because the gasket 200 and the ram 110 are directly connected to each other, the distance between the syringe 290 and the pressing unit 4 can be shortened. This allows the size of the injection head 2 in the injection system 1 to be reduced. Furthermore, the gasket 200 according to the second embodiment can also suppress adhesion of foreign matter to the engaging claws 222.

[0050] It is also possible to attach the gasket 100 of the first embodiment to the cylinder 291 of the second embodiment.

[0051] [Third embodiment] In the third embodiment, the engaging claws 322 of the gasket 300 include a protrusion 328 and a recess 329. The third embodiment will be described below with reference to Fig. 10. In the description of the third embodiment, differences from the first embodiment will be described, and the components described in the first embodiment will be given the same reference numerals and their description will be omitted. Unless otherwise specified, components given the same reference numerals perform substantially the same operations and functions, and their effects are also substantially the same.

[0052] The protrusion 328 of the engagement claw 322 has an outer shape corresponding to a quarter of a sphere, and is configured to be flush with the engagement claw 322 on the rear end surface of the plunger 320 of the gasket 300. Therefore, when viewed from the rear side of the plunger 320, the protrusion 328 has a substantially semicircular shape. The protrusion 328 protrudes toward one adjacent engagement claw 322. The engagement claw 322 also has a recess 329 that receives the protrusion 328 of another adjacent engagement claw 322. This recess 329 has a shape complementary to the protrusion 328, and is formed at a position facing the protrusion 328 of the other adjacent engagement claw 322. When viewed from the rear side of the plunger 320, the recess 329 also has a substantially semicircular shape, and the outer dimensions of the protrusion 328 and the inner dimensions of the recess 329 are set to match.

[0053] After the front end 111 of the ram 110 is inserted, the ram 110 pushes the gasket 300 via the front end 111, causing the gasket 300 to advance within the cylinder 91. As the gasket 300 advances, the engaging claws 322 are displaced toward the center of the hole H in the intake suction cup 320 by a reaction force from the inner surface of the cylinder 91. At this time, the engaging claws 322 are deformed from the center of the bottom of the annular groove 125 as a starting point. Furthermore, as the gasket 300 is inserted into the cylinder 91, the engaging claws 322 are compressed by the reaction force from the inner surface of the cylinder 91.

[0054] At the same time, adjacent engaging claws 322 are displaced toward each other. As a result, convex portions 328 are received in concave portions 329 and engage with the concave portions 329. This engagement between the two keeps the distance between the perpendicular line P of the hole H and the multiple engaging claws 322 constant, preventing the inserted ram 110 from becoming misaligned within the hole H. Thereafter, when the gasket 300 advances further within the cylinder 91, the seal member 140 presses against the medicinal liquid within the cylinder 91. This causes the medicinal liquid to be forced out of the tip portion 93 and injected into the patient's body via an extension tube or the like.

[0055] After the chemical solution is injected, the ram 110 retracts, and the gasket 300 connected to the ram 110 also retracts. The ram 110 and the gasket 300 then retract to a position where they are no longer restricted by the inner surface of the cylinder 91. This causes the engagement claws 322 to spread outward, and the protrusions 124 disengage from the engagement grooves 112. As a result, the protrusions 124 disengage from the engagement grooves 112. When the ram 110 retracts further, the ram 110 disengages from the gasket 300.

[0056] The ram 110 and gasket 300 according to the third embodiment also prevent the ram 110 from rattling relative to the gasket 300 when the gasket 300 and the ram 110 are connected. Furthermore, because the gasket 300 and the ram 110 are directly connected, the distance between the syringe 90 and the pressing unit 4 can be shortened. This allows the size of the injection head 2 in the injection system 1 to be reduced. Furthermore, the distance between the perpendicular line P of the hole H and the multiple engaging claws 322 can be kept constant.

[0057] It should be noted that the protrusions 328 may have other shapes. For example, the protrusions 328 may have a shape corresponding to a triangular prism or a cylinder bisected longitudinally. In this case, the protrusions 328 extend along the perpendicular line P, and the recesses 329 have a shape complementary to the protrusions 328.

[0058] Although the present invention has been described above with reference to each embodiment, the present invention is not limited to the above-described embodiments. The present invention also includes inventions that have been modified within the scope of the present invention and inventions equivalent to the present invention. Furthermore, the above-described embodiments and modifications can be combined as appropriate within the scope of the present invention.

[0059] For example, notches or holes may be formed in the engaging claws 122, 222, and 322. This causes deformation of the portions where the notches or holes are formed, making it easier for the engaging claws 122, 222, and 322 to be displaced. The inner surface S1 of the gasket does not have to be divided into two surfaces. For example, the inner surface S1 may be configured as a continuous inclined or curved surface. Furthermore, the gaskets 100, 200, and 300 have an outer shape in which the cross section perpendicular to the perpendicular line P is substantially circular. However, the gaskets 100, 200, and 300 may have an outer shape in which the cross section perpendicular to the perpendicular line P is substantially elliptical. In this case, the sealing members 140 and 240 and the syringes 90 and 290 have inner shapes complementary to those of the gaskets 100, 200, and 300.

[0060] The syringes 90, 290 filled with the medicinal liquid may be prefilled syringes. The medicinal liquid may be manually filled into the syringes 90, 290, or may be filled into the syringes 90, 290 by the injection head 2 or a filler. The syringes 90, 290 may be provided with a data carrier such as an RFID or barcode. Information about the medicinal liquid is recorded on this data carrier. The injection system 1 can then read the recorded information from the data carrier via the injection head 2 and control the amount of medicinal liquid to be injected. For example, the control device can calculate the optimal injection amount per body weight based on the read medicinal liquid information (iodine amount) and display it on the touch panel of the console.

[0061] [Variations] As shown in FIG. 11 , a notch 496 may be formed in a portion of the outer periphery of the flange 492. Specifically, the flange 492 has two arc portions 497 that are arc-shaped relative to the central axis C of the syringe 490. Furthermore, the flange 492 has two flat portions 498 that face each other between the arc portions 497. As an example, the flat portions 498 can be formed by cutting a portion of the flange 492 linearly and parallel to each other. Then, a positioning notch 496 is formed in the approximate center of each arc portion 497 so as to be point-symmetrical with respect to the central axis C. In other words, the notches 496 are formed so that the line connecting the two notches 496 and the flat portions 498 are parallel to each other. Furthermore, the adapter 8 is provided with an engaging portion that engages with the notches 496, such as a locking claw, a protrusion, or a latch.

[0062] The syringe 490 configured in this manner is fitted into the adapter 8 with the flange 492 parallel to the groove of the adapter 8. At this time, the syringe 490 is fitted into the adapter 8 so that the flat portion 498 faces the engaging portion of the adapter 8. The syringe 490 is then rotated 90 degrees to engage the engaging portion with the notch 496. This allows the syringe 490 to be attached to the adapter 8. When the engaging portion engages with the notch 496, the syringe 490 is positioned relative to the adapter 8 so that the flat portion 498 is horizontal. This allows the syringe 490 to be properly held in the adapter 8 and prevents damage to the syringe 490. Furthermore, because rattle of the ram 110 is suppressed, the ram 110 can be inserted straight into the syringe 490. This prevents leakage of the chemical solution from the gasket 100 to the syringe 490, even when the chemical solution is injected at high pressure. Alternatively, one or more notches 496 may be formed, and the notches 496 may be formed in the flat portion 498 .

[0063] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.

[0064] (Appendix 1) A method for manufacturing a gasket including a plunger having an insertion portion and an engaging claw, and an O-ring and a seal member attached to the plunger, The O-ring is attached in a groove formed in the engaging claw, A method for manufacturing a gasket, comprising inserting the insertion portion into a space within the seal member and attaching the seal member to the insertion portion.

[0065] This application claims priority from Japanese Patent Application No. 2018-171532, filed on September 13, 2018, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0066] 1: injection system, 2: injection head, 90: syringe, 91: cylinder, 100: gasket, 110: ram, 112: engagement groove, 122: engagement claw, 124: protrusion, 125: annular groove, 126: first inner surface, 127: second inner surface, 130: O-ring, 200: gasket, 222: engagement claw, 224: protrusion, 225: annular groove, 295: skirt portion, 226: first inner surface, 227: second inner surface, 290: syringe, 291: cylinder, 300: gasket, 322: engagement claw, 328: convex portion, 329: concave portion, 490: syringe, B: boundary portion, H: hole, P: perpendicular line, S1: inner surface, S2: outer surface

Claims

1. a gasket having a plurality of engaging claws including an inner surface defining a hole with an enlarged entrance and an outer surface inclined in a direction away from a perpendicular line passing through the center of the hole, the engaging claws being displaceable between an enlarged position and a narrowed position; a ram inserted into the hole to engage the engagement pawl; a cylinder into which the gasket is inserted, the cylinder abutting against the outer surface of the engaging claw of the gasket after insertion; an injection device configured to advance the ram and to inject a chemical solution into the cylinder; An injection system, wherein the gasket has an annular groove formed therein, which serves as a starting point for deformation of the engaging claw.

2. 2. The injection system of claim 1, wherein the inner surface includes a first inner surface and a second inner surface inclined away from the perpendicular line, and the annular groove is formed at a position corresponding to a boundary portion between the first inner surface and the second inner surface.

3. The engaging claw has a protrusion that protrudes toward the perpendicular line, The injection system of claim 1 or 2, wherein the ram has an engagement groove into which the protrusion is engaged.

4. The injection system of claim 2 , wherein the first inner surface extends parallel to the normal.

5. The injection system of claim 1 , wherein the gasket includes an O-ring mounted in a groove formed in the engagement pawl.

6. The injection system according to claim 1 , wherein the cylinder has a skirt portion that covers the engaging claw.

7. The injection system of claim 6 , wherein the inner surface of the skirt is sloped along the outer surface so that the engagement pawls are in the expanded position.

8. The injection system according to claim 1 , wherein the engagement claw has a protrusion that protrudes toward one adjacent engagement claw and a recess that receives the protrusion of another adjacent engagement claw.

9. a gasket having a plurality of engaging claws including an inner surface defining a hole with an enlarged entrance and an outer surface inclined in a direction away from a perpendicular line passing through the center of the hole, the engaging claws being displaceable between an enlarged position and a narrowed position; a cylinder into which the gasket is inserted, the cylinder abutting against the outer surface of the engaging claw of the gasket after insertion; The gasket has an annular groove formed therein, which serves as a starting point for deformation of the engaging claw.

10. a plurality of engaging claws including an inner surface defining a hole with an enlarged entrance diameter and an outer surface inclined in a direction away from a perpendicular line passing through the center of the hole, the engaging claws being displaceable between an enlarged position and a narrowed position; The gasket has an annular groove formed therein, which serves as a starting point for deformation of the engaging claw.

Images