Injection device and injection device holder

Abstract

To miniaturize an injection head.SOLUTION: An injection system 1 comprises: a gasket 100 including a plurality of engagement pawls 122 and a distal end part 140 having a cross-sectional shape being a long elliptic shape where a length in a height direction is longer than a length in a width direction orthogonal to the height direction; a ram 110 to be engaged with the gasket 100; a cylinder 91 to which the gasket 100 is inserted; and an injection device 2 for allowing the ram 110 to move forward so as to inject a medical solution inside the cylinder 91. Each one of the engagement pawls 122 is displaced between a widened position and a narrowed position, and includes an inner surface S for defining a hole H having an inlet with an enlarged diameter so as to be inclined in a separating direction from a perpendicular line P passing the center of the hole H. In the engagement pawls 122, the two engagement pawls 122 aligning in a height direction have the same shape and size and the two engagement pawls 122 aligned in a width direction have the same shape and size.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to an injection system equipped with a syringe filled with a chemical solution.

Background Art

[0002] Conventionally, as a ram and a gasket used for a syringe for injecting a chemical solution, 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 this plunger. Then, when the plunger advances in the syringe until it reaches the second inner diameter, the expandable and contractible portion contracts. As a result, the tab of the plunger (gasket) engages with the groove of the plunger shaft (ram).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the miniaturization of the injection device is not sufficiently achieved.

Means for Solving the Problems

[0005] To solve the above problems, an injection system as an example of the present invention includes a gasket having a plurality of engaging claws and a tip portion having an elliptical cross-sectional shape whose length in the height direction is longer than the length in the width direction orthogonal to the height direction, a ram that engages with the gasket, a cylinder into which the gasket is inserted, and an injection device configured to advance the ram and inject a chemical solution in the cylinder. The plurality of engaging claws are displaced between a widened position and a narrowed position, and include an inner surface that defines a hole with an enlarged diameter at the entrance and is inclined in a direction away from a perpendicular line passing through the center of the hole. Among the plurality of engaging claws, two engaging claws arranged in the height direction have the same shape and size, and two engaging claws arranged in the width direction have the same shape and size. Also, a syringe as another example of the present invention includes a gasket having a plurality of engaging claws and a tip portion having an elliptical cross-sectional shape whose length in the height direction is longer than the length in the width direction orthogonal to the height direction, and a cylinder into which the gasket is inserted. The plurality of engaging claws are displaced between a widened position and a narrowed position, and include an inner surface that defines a hole with an enlarged diameter at the entrance and is inclined in a direction away from a perpendicular line passing through the center of the hole. Among the plurality of engaging claws, two engaging claws arranged in the height direction have the same shape and size, and two engaging claws arranged in the width direction have the same shape and size. Furthermore, a gasket as another example of the present invention includes a plurality of engaging claws and a tip portion having an elliptical cross-sectional shape whose length in the height direction is longer than the length in the width direction orthogonal to the height direction. The plurality of engaging claws are displaced between a widened position and a narrowed position, and include an inner surface that defines a hole with an enlarged diameter at the entrance and is inclined in a direction away from a perpendicular line passing through the center of the hole. Among the plurality of engaging claws, two engaging claws arranged in the height direction have the same shape and size, and two engaging claws arranged in the width direction have the same shape and size.

[0006] Further features of the present invention will become apparent from the following description of exemplary embodiments illustrated with reference to the accompanying drawings.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0008] 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 the components described in the following embodiments are arbitrary and can be changed according to the configuration of the device to which the present invention is applied or various conditions. Also, 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 side of the syringe, and the opposite side corresponds to the rear side ( "rear").

[0009] [First Embodiment] Figures 1 and 2 are schematic perspective views of an injection system 1 for injecting a chemical solution. Figure 1 shows the injection system 1 before mounting the syringe 90, and Figure 2 shows the injection system 1 after mounting the syringe 90. As shown in Figure 1, the injection system 1 includes an injection head 2 which is an example of an injection device. This injection head 2 is configured to advance the ram 110 and inject the chemical solution in the cylinder 91 of the syringe 90.

[0010] The injection system 1 is connected to an imaging device (not shown) either wired or wirelessly. And during the injection of the chemical solution and the taking of images, various data are 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 angiography device, a PET (Positron Emission Tomography) device, a SPECT (Single Photon Emission Computed Tomography) device, a CT angiography device, an MR angiography device, an ultrasonic diagnostic device, and a vascular imaging device.

[0011] The injection head 2 of the injection system 1 includes a pressing portion 4 that presses a gasket 100 (Figure 4) inserted into the syringe 90. The pressing portion 4 is controlled to press and advance the gasket 100 in the syringe 90 by a control unit (not shown) in order to send out the chemical solution in the syringe 90. Further, the pressing portion 4 includes a drive mechanism (not shown) and a ram 110 connected to the drive mechanism. Specifically, the control unit controls the motor in the injection head 2 so that the ram 110 advances when the motor rotates forward and the ram 110 retracts when the motor rotates in reverse. Furthermore, the injection head 2 may include a reading portion that reads a data carrier such as RFID or a barcode provided on the syringe 90.

[0012] The drive mechanism of the pressing unit 4 includes a transmission mechanism connected to the shaft of the motor, 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 has a pinion gear connected to the shaft and a screw gear connected to the ball screw shaft. The transmission mechanism transmits the rotation from the motor to the ball screw shaft. Therefore, the rotation of the shaft of the motor is transmitted to the ball screw shaft via the pinion gear and the screw gear. As a result, the ball screw shaft rotates according to the transmitted rotation. The ball screw nut slides in the forward or backward direction as the ball screw shaft rotates. As the ball screw nut slides, the ram 110 of the pressing unit 4 moves forward or backward.

[0013] In addition, the injection system 1 includes a console (not shown) having a touch panel as a display unit for displaying the injection status of the chemical solution, and a control device (not shown) having a control unit and a power supply. The console and the injection head 2 can be connected to each other by wire or wirelessly. Further, a remote operation device such as a hand switch may be connected to the console by wire or wirelessly. The chemical solution injection can also be started or stopped by this remote operation device. The injection head 2 and the control device can be integrally configured with a caster stand (not shown). Alternatively, the injection head 2 and the control device may be separate bodies, and each may be mounted on a caster stand.

[0014] The control device stores in advance data on the operation pattern (injection protocol) and data on the chemical solution. When injecting a chemical solution into a patient, the operator operates the touch panel of the console to input the patient's physical data such as the injection rate, injection volume, injection time, body weight, height, body surface area, heart rate, and cardiac output, and the data on the type of chemical solution. Then, the control device calculates the optimal injection conditions according to the input data and the data stored in advance. After that, the control device determines the amount of the chemical solution to be injected into the patient and the injection protocol based on the calculated injection conditions.

[0015] In addition, when the control device determines the amount of the chemical solution and the injection protocol, it causes a predetermined data or graph to be displayed on the touch panel of the console. Thereby, the operator can check the displayed data or graph. The data of the operation pattern (injection protocol) and the data of the chemical solution can also be input from an external storage medium. Alternatively, a head display may be provided on the injection head 2, and the control device may cause a predetermined data or graph to be displayed on the head display. When this head display is a touch panel, the operator can set injection conditions and the like from the head display. Further, the head display may be built into the injection head 2, or may be attached to the side of the injection head 2.

[0016] When injecting the chemical solution, the operator turns on the power of the injection head 2 and mounts the syringe 90 on the injection head 2 as shown in FIG. 2. Thereafter, the operator presses the injection button displayed on the touch panel. When the injection button is pressed, the control unit sends a forward rotation signal as a drive voltage to the motor. In response to this forward rotation signal, the shaft of the motor rotates forward, and the ram 110 of the pressing unit 4 moves forward. Thereafter, when the injection is completed and the syringe 90 is removed, the control unit sends a reverse rotation signal as a drive voltage to the motor in order to retract the ram 110. In response to this reverse rotation signal, the shaft of the motor rotates in reverse, and the ram 110 moves backward.

[0017] When an operation panel is provided on the injection head 2, the operator can also press the injection button on this operation panel. Further, the operator can also start the injection by pressing the button of the hand switch. Alternatively, the operator may turn on the power of the injection head 2 after mounting the syringe 90.

[0018] FIG. 3 is a schematic perspective view showing an adapter 8 for mounting a syringe 90 on an injection head 2. As shown in FIG. 3, the adapter 8 has two groove portions having a substantially U-shaped cross-sectional shape and can be detachably attached to a holder 7 of the injection head 2. As an example, the holder 7 has a receiving portion 71 having a shape complementary to the outer shape of the adapter 8. Then, the operator attaches the adapter 8 to the holder 7 so as to be inserted into the receiving portion 71. Note that the adapter 8 may be integrally formed with the holder 7.

[0019] Further, a stepped portion 72 protruding inward is formed in the holder 7. Thereby, a groove that forms a gap for receiving a flange 92 (FIG. 4) of the syringe 90 is defined between the adapter 8 and the holder 7. The holder 7 also has two holding portions 73 having a substantially U-shaped cross-sectional shape so as to hold the rear end portion of the syringe 90. That is, the syringe 90 has a substantially elliptical cross-sectional shape, and the holding portion 73 of the holder 7 has a shape complementary to the outer shape of the syringe 90. As a result, the width of the holding portion 73 in the horizontal direction also decreases by the amount by which the width of the syringe 90 in the horizontal direction perpendicular to the vertical direction of the syringe 90 decreases. As a result, the width of the injection head 2 in the horizontal direction can be decreased, and the size of the injection head 2 can be reduced. That is, compared with the case where the syringe 90 has a circular cross-sectional shape, since the width of the syringe 90 is decreased, the injection head 2 can be miniaturized. According to this small injection head 2, the injection system 1 can be installed in a CT examination room with a smaller space. In particular, in the injection head 2 capable of mounting two syringes 90, the effect of miniaturization is great. Alternatively, the holder 7 may be configured so that one or three or more syringes 90 can be mounted. In this case, the holding portions 73 are formed in a number corresponding to the number of syringes 90 that can be mounted.

[0020] Also, on the front surface of the adapter 8, a pair of engaging portions 83 are formed so as to be positioned sandwiching the holding portion 73. These engaging portions 83 have, as an example, a straight portion extending downward and a protruding portion formed at the lower end of the straight portion. And the engaging portion 83 has elasticity and is deformed by being pushed by a protrusion 95 (FIG. 4) formed on the rear surface of the cylinder 91. Specifically, when the engaging portion 83 is pushed by the protrusion 95, it is displaced rearward. After that, the engaging portion 83 is displaced forward by its own elasticity and returns to its original position. As a result, the protruding portion of the engaging portion 83 gets over the protrusion 95 and is positioned above it. As a result, since the engaging portion 83 and the protrusion 95 come into contact, the upward movement of the syringe 90 is restricted by the engaging portion 83.

[0021] Furthermore, when the protrusion 95 gets over the engaging portion 83, the operator can obtain a clicking feeling. Thereby, the operator can perceive that the syringe 90 is mounted at the correct position. Alternatively, only one engaging portion 83 may be formed on one side with respect to the holding portion 73, or a total of three or more engaging portions 83 may be formed on both sides with respect to the holding portion 73. Note that the engaging portion 83 may have other configurations as long as it has a protruding portion configured to be able to advance and retreat. For example, the engaging portion 83 may be composed of an elastic body protruding forward and a cover member covering the elastic body.

[0022] Also, the adapter 8 is formed with a hole portion 82 for discharging a liquid such as a chemical solution to the outside of the injection head 2. Specifically, when the liquid spills on the adapter 8, the liquid can be discharged to the outside through this hole portion 82. Therefore, the holder 7 is also formed with an opening (not shown) corresponding to the hole portion 82. Note that the adapter 8 may be configured such that the syringe 90 is mounted thereon. In this case, the adapter 8 is formed with a groove for receiving the flange 92 and a holding portion for holding the syringe 90. Furthermore, the adapter 8 may be omitted and a groove for receiving the flange 92 may be formed in the holder 7.

[0023] Figure 4 is a schematic exploded perspective view of the syringe 90, showing the syringe 90 as viewed from the upper front side. As shown in Figure 4, the syringe 90 includes a cylinder 91 having a tip portion 93 and a flange 92 inserted between the adapter 8 and the holder 7. Further, the syringe 90 has a gasket 100 that is slidable within the cylinder 91. This gasket 100 is inserted into the cylinder 91, and the outer surface of the inserted gasket 100 abuts against the inner surface of the cylinder 91. Also, the gasket 100 engages with the front end portion 111 of the ram 110 and slides within the cylinder 91 by the ram 110.

[0024] The gasket 100 includes a seal member 140 as a tip portion having an elliptical cross-sectional shape. In the cross-section of this seal member 140, the length in the height direction is longer than the length in the width direction orthogonal to the height direction. Also, the gasket 100 includes a sucker 120 having a plurality of divided engaging claws 122, and the tip of the sucker 120 is inserted into the seal member 140. The sucker 120 is made of an elastic resin such as POM (polyacetal resin), for example, and can be manufactured by molding. Also, the seal member 140 is made of butyl rubber, for example, and can be manufactured by molding.

[0025] The gasket 100 is engaged with the ram 110 when the engaging claws 122 engage with the front end portion 111 of the ram 110. Then, when the motor rotates forward with the engaging claws 122 connected to the ram 110, the pressing portion 4 pushes the ram 110 in the forward direction. Then, when the ram 110 and the gasket 100 move forward, the chemical solution in the cylinder 91 is pushed out through the tip portion 93. As a result, the chemical solution is injected into the patient's body through an extension tube or the like connected to the tip portion 93. After the injection of the chemical solution, when the motor rotates in reverse, the pressing portion 4 pulls the ram 110 in the backward direction and the gasket 100 moves backward. Note that the engaging claws 122 may be provided with grooves into which O-rings are fitted. In this case, by fitting the O-ring, the spread of the engaging claws 122 can be restricted. Also, the tip portion 93 can be connected to an extension tube via a lock connector, a luer lock, a push-in type connector, or the like.

[0026] The cylinder 91 into which the gasket 100 is inserted has a cross-sectional shape complementary to that of the gasket 100. That is, the cylinder 91 has a substantially elliptical cross-sectional shape, and the length in the height direction in the cross-section is longer than the length in the width direction orthogonal to the height direction. Therefore, when the rear end portion of the syringe 90 is held by the holding portion 73 of the holder 7, both side surfaces of the rear end portion come into contact with the inner surface of the holding portion 73. Thereby, the syringe 90 is prevented from rotating with respect to the holder 7. For example, when injecting a chemical solution, the gasket 100 is pushed into the cylinder 91 by the ram 110 that advances while rotating. At this time, a rotational force is also transmitted to the syringe 90 via the gasket 100. However, since both side surfaces of the rear end portion come into contact with the inner surface of the holding portion 73, the rotation of the syringe 90 is prevented.

[0027] 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 the hollow pipe. Further, the front end portion 111 may be manufactured using a material other than stainless steel or aluminum, for example, a material having a higher hardness than the gasket 100. An annular engaging groove 112 extending in the circumferential direction is formed in the front end portion 111. Then, the gasket 100 and the ram 110 are engaged by inserting the protrusion 124 (FIG. 6) of the engaging claw 122 into the engaging groove 112.

[0028] Figure 5 is a schematic rear view of the syringe 90 with the gasket 100 inserted. As shown in Figure 5, the syringe 90 has projections 95, and a total of four projections 95 are formed in two on each side with respect to the cylinder 91. And the projection 95 protrudes laterally from an annular portion 96 that protrudes rearward from the flange 92. That is, a substantially ring-shaped annular portion 96 is formed on the flange 92, and the projection 95 is formed so as to protrude from the annular portion 96. This projection 95 overrides the engaging portion 83 of the adapter 8 when mounting the syringe 90. And after the syringe 90 is mounted, since the engaging portion 83 abuts against the projection 95, the upward movement of the syringe 90 is restricted. Alternatively, only one projection 95 may be formed on one side with respect to the hole H formed in the center of the gasket 100, or a total of three or more projections 95 may be formed on both sides with respect to the hole H.

[0029] The flange 92 has a substantially elliptical outer shape. However, the length L1 in the height direction (the vertical direction in Figure 5) of the first portion 97 located on the lower side in Figure 5 is longer than the length L2 in the height direction of the second portion 98 located on the upper side. That is, the length L1 of the first portion 97 extending upward from the cylinder 91 in the height direction is longer than the length L2 of the second portion 98 extending downward. Thereby, the operator can visually recognize the correct orientation and the vertical direction of the syringe 90. Also, by making the first portion 97 longer, the contact area between the holder 7 or the adapter 8 and the flange 92 increases. Thereby, since the syringe 90 can be stably held, it can withstand a higher injection pressure. Furthermore, an arrow 99 indicating the insertion direction is attached to the first portion 97 of the flange 92.

[0030] Alternatively, the second portion 98 extending upward may be made longer than the first portion 97 extending downward. Even in this case, the operator can visually recognize the correct orientation and insertion direction of the syringe 90. Further, when the second portion 98 extending upward is long, it is possible to prevent the second portion 98 from being erroneously inserted downward when the flange 92 is inserted into the groove between the holder 7 and the adapter 8. That is, since the depth of the groove corresponds to the length of the shorter first portion 97, if inserted in the wrong orientation, the second portion 98 will hit the bottom of the groove before the protrusion 95 overrides the engaging portion 83. Therefore, the operator cannot obtain a clicking sensation and can recognize that the orientation is incorrect. Thereby, the operator can correct the syringe 90 to the correct orientation and mount it.

[0031] In the gasket 100, the two engaging claws 122 arranged in the height direction, which is one direction, have the same shape and size. Also, the two engaging claws 122 arranged in the width direction, which is the other direction orthogonal to the height direction, have the same shape and size. Thereby, the displacement amounts of the engaging claws 122 can be made substantially the same in the height direction and the width direction orthogonal thereto. That is, since the gasket 100 has a substantially elliptical outer shape, if the shapes and sizes of the plurality of engaging claws 122 are made the same, the displacement amounts from the start of displacement of the engaging claws 122 will be different in the height direction and the width direction. Therefore, the shapes and sizes of the engaging claws 122 arranged in the height direction and the engaging claws 122 arranged in the width direction are made different so that the displacement amounts of all the engaging claws 122 are substantially the same. That is, in the gasket 100 having a substantially elliptical outer shape, the two engaging claws 122 arranged in the height direction are both formed to have the same size. Also, in the gasket 100, the two engaging claws 122 arranged in the width direction are both formed to have the same size. And, a substantially circular hole H into which the front end portion 111 of the ram 110 is inserted is formed in the central portion surrounded by the four engaging claws 122. Therefore, the height of the engaging claws 122 arranged in the height direction is longer than the height of the engaging claws 122 arranged in the width direction. Also, a substantially fan-shaped recess 129 is formed in each engaging claw 122. Further, a protrusion 124 that engages with the engaging groove 112 of the ram 110 is formed on the periphery of the hole H. And when the ram 110 is inserted until the end face of the front end portion 111 abuts against the bottom of the hole H, the engaging groove 112 and the protrusion 124 face each other.

[0032] Figure 6 is a schematic cross-sectional view of the gasket 100 along the front-rear direction and the height direction. The suction cup 120 has a substantially disk-shaped insertion portion 121, and a plurality of intersecting ribs (not shown) are formed in the insertion portion 121. Also, an annular groove 125 is formed between the insertion portion 121 and the engaging claw 122. Further, the seal member 140 has an annular protrusion 141 formed on its outer periphery. And when this annular protrusion 141 abuts against the inner surface of the cylinder 91, the cylinder 91 is sealed. In FIG. 2, three annular protrusions 141 are formed, but two or one, or four or more annular protrusions may be formed. Also, a space for accommodating the insertion portion 121 is formed in the seal member 140, and the rear end portion of the seal member 140 protrudes toward the space.

[0033] The engaging claw 122 of the suction cup 120 is formed with a substantially fan-shaped recess 129. By means of the recess 129, the wall thickness of the engaging claw 122 can be reduced. Therefore, the engaging claw 122 is more deformable than the insertion portion 121. Also, the portion where the annular groove 125 is formed is thinner than the portion where the engaging claw 122 is formed and the insertion portion 121. Thereby, the annular groove 125 serves as a starting point for the deformation of the engaging claw 122. The bottom of this annular groove 125 has a substantially semi-circular cross-sectional shape. Alternatively, the bottom of the annular groove 125 may have a substantially trapezoidal or substantially triangular cross-sectional shape that tapers inward.

[0034] The hole H of the suction cup 120 tapers towards the bottom. When the ram 110 is inserted into the hole H, the end face of the front end portion 111 abuts against the bottom of the hole H. And in the state where the end face of the front end portion 111 abuts against the bottom of the hole H, a gap is formed between the outer surface of the front end portion 111 and the inner surface S of the hole H. That is, the inner surface S of the hole H is inclined towards the center of the bottom. Therefore, the front end portion 111 inserted into the hole H is guided to slide on the inner surface S inclined towards the center of the bottom. Thereby, the front end portion 111 can be aligned with the center of the hole H.

[0035] FIG. 7 is a schematic perspective view of the gasket 100 as viewed from the rear. As shown in FIG. 7, the suction cup 120 of the gasket 100 includes a plurality of engaging claws 122 having a substantially fan-shaped shape, for example, four engaging claws 122. Alternatively, the suction cup 120 may include two or three, or five or more engaging claws 122. Also, a gap is formed between adjacent engaging claws 122, and when the gasket 100 advances in the cylinder 91, each engaging claw 122 is displaced so that the adjacent engaging claws 122 approach each other. Since all of the gaps have the same length and width, it is possible to suppress fluctuations in the position of each engaging claw 122 with respect to the ram 110 during displacement. That is, as the gasket 100 advances, each engaging claw 122 is displaced so as to approach each other by the same distance.

[0036] Each engaging claw 122 has a protrusion 124 that engages with the engaging groove 112 of the ram 110. This protrusion 124 protrudes toward the center of the suction cup 120. Also, the tip of the protrusion 124 is rounded so as to be easily inserted into the engaging groove 112. In FIG. 7, reference numerals are attached to only one protrusion 124. However, the protrusion 124 is formed on all of the four engaging claws 122.

[0037] Also, an annular groove 125 is formed between the insertion portion 121 and the engaging claw 122. At the portion where the annular groove 125 is formed, the engaging claw 122 is connected to the insertion portion 121. In order to facilitate the displacement (deformation) of the engaging claw 122, the portion where the annular groove 125 is formed is thinner than the portion where the protrusion 124 is formed. Further, a hole H surrounded by the protrusion 124 is formed in the suction cup 120, and the ram 110 is inserted into the hole H so as to engage with the engaging claw 122.

[0038] [Connection between Ram 110 and Gasket 100] With reference to FIGS. 8 and 9, the connection between the ram 110 and the gasket 100 will be described. FIG. 8 is a schematic cross-sectional view of the syringe 90 before the ram 110 is inserted into the hole H of the suction cup 120. FIG. 9 is a schematic cross-sectional view of the syringe 90 in a state where the ram 110 has advanced the gasket 100. Also, FIGS. 8 and 9 show a cross-section along the longitudinal direction passing through the central axis of the cylinder 91. For convenience of explanation, in FIGS. 8 and 9, the suction cup 120 and the seal member 140 are integrally shown. Also, in FIGS. 8 and 9, only the upper half in the height direction of the ram 110 and the gasket 100 is shown. The lower part in the height direction of the ram 110 and the gasket 100 has substantially the same shape as the upper part except for the flange 92.

[0039] As shown in FIG. 8, the gasket 100 has a hole H with a widened inlet. That is, at the hole H, the inlet into which the ram 110 is inserted has a longer inner diameter compared to the bottom surface pressed by the end face of the front end portion 111 of the ram 110. Further, the gasket 100 has an engaging claw 122 that displaces between a widened position (FIG. 8) and a narrowed position (FIG. 9). This engaging claw 122 includes an inner surface S that defines the hole H and is inclined in a direction away from the perpendicular line P passing through the center of the hole H (bottom).

[0040] The engaging claw 122 has a ridge 128 that protrudes in a direction away from the perpendicular line P passing through the center of the hole H. Further, at the rear end portion of the cylinder 91, a diameter-expanded portion 94 for receiving the ridge 128 is formed. That is, the inner diameter of the rear end portion of the cylinder 91 is larger compared to the inner diameters of other portions. When the gasket 100 is assembled to the cylinder 91, the ridge 128 is received in the diameter-expanded portion 94, and the entire gasket 100 is accommodated in the cylinder 91. Alternatively, the rear portion of the engaging claw 122 may protrude outward from the cylinder 91. Further, the engaging claw 122 has a protrusion 124 that protrudes inward of the hole H. And the ram 110 has an annular engaging groove 112 that engages with the protrusion 124. Note that the diameter-expanded portion 94 may be an inclined surface or a curved surface that narrows toward the center of the cylinder 91 in addition to the stepped difference.

[0041] As shown in FIG. 9, when the ram 110 is inserted into the hole H, the end face of the front end portion 111 abuts against the bottom of the hole H. When the ram 110 pushes the gasket 100, the gasket 100 advances in the cylinder 91. When the gasket 100 advances, the ridge 128 of the engaging claw 122 abuts against the diameter-expanded portion 94 of the cylinder 91. And when advancing and the ridge 128 passes through the diameter-expanded portion 94, the engaging claw 122 displaces toward the perpendicular line P. At this time, the engaging claw 122 deforms starting from the center of the bottom of the annular groove 125.

[0042] As a result, even if the front end portion 111 is inserted into the hole H at a position offset from the vertical line P, the front end portion 111 is displaced so that the central axis of the front end portion 111 aligns with the vertical line P. That is, the front end portion 111 is pushed against the portion corresponding to the bottom of the annular groove 125 and displaced toward the center of the hole H. Therefore, it is possible to suppress the central axis of the ram 110 from tilting with respect to the gasket 100. As shown in FIG. 9, when the protrusion 128 passes through the enlarged diameter portion 94, the engaging claw 122 narrows. Then, the protrusion 124 of the engaging claw 122 at the narrowed position enters the engaging groove 112, and the protrusion 124 engages with the engaging groove 112. Thereby, the gasket 100 is connected to the ram 110. Further, as the engaging claw 122 is displaced, the annular groove 125 deforms so as to expand.

[0043] After that, when the gasket 100 advances in the cylinder 91, the seal member 140 presses the chemical solution in the cylinder 91. As a result, the chemical solution is pushed out from the tip portion 93 and injected into the patient's body through an extension tube or the like. After the injection of the chemical solution, the ram 110 retracts, and the gasket 100 connected to the ram 110 also retracts. Then, when the ram 110 and the gasket 100 retract until the protrusion 128 is received in the enlarged diameter portion 94, the engaging claw 122 expands outward and the protrusion 124 disengages from the engaging groove 112.

[0044] As a result, the protrusion 124 engages and disengages with the engaging groove 112. That is, when the ram 110 and the gasket 100 retract until the engaging claw 122 is displaced to the expanded position, the protrusion 124 comes out of the engaging groove 112. Further, as the engaging claw 122 is displaced, the annular groove 125 narrows so as to return to its original shape. When the ram 110 further retracts, the gasket 100 stays at the position shown in FIG. 8 due to the frictional force between the seal member 140 and the cylinder 91. As a result, the ram 110 disengages from the gasket 100 and retracts to the position before insertion shown in FIG. 8.

[0045] According to the ram 110 and the gasket 100 according to the first embodiment as described above, the engaging claws 122 are deformed starting from the center of the bottom of the annular groove 125. Therefore, the plurality of engaging claws 122 are evenly displaced toward the perpendicular line P of the suction cup 120. Thereby, when the ram 110 is detached from the gasket 100, it is possible to suppress the front end portion 111 from being located at a position biased with respect to the perpendicular line P. Therefore, it is possible to prevent the engaging groove 112 of the front end portion 111 from being caught by the protrusion 124.

[0046] Also, according to the ram 110 and the gasket 100 according to the first embodiment, when connecting the gasket 100 and the ram 110, it is possible to suppress the ram 110 from rattling with respect to the gasket 100. Furthermore, since the gasket 100 and the ram 110 are directly connected, the distance between the syringe 90 and the pressing portion 4 can be shortened. Therefore, the size of the injection head 2 in the injection system 1 can be reduced.

[0047] Furthermore, according to the syringe 90 according to the first embodiment, compared with the case of having a substantially circular cross-sectional shape, the size in the width direction can be reduced. That is, the width of the syringe 90 can be narrowed, or the size of the syringe 90 can be reduced. And by increasing the size in the height direction of the syringe 90 so as to have a substantially elliptical cross-sectional shape, a syringe 90 having the same capacity and being small can be formed. As a result, the injection head 2 can be miniaturized and lightened. In particular, when an actuator having a rotation transmission mechanism housed in a case is built in the frame of the injection head 2, the injection head 2 can be miniaturized synergistically. Furthermore, by increasing the size in the height direction, the contact area with the holding portion 73 increases. Thereby, the syringe 90 can be stably fixed.

[0048] Also, according to the syringe 90 according to the first embodiment, the syringe 90 can be held by the holding portion 73 simply by inserting the syringe 90 into the holding portion 73. Thereby, the operation of rotating the syringe 90 and attaching it to the injection head 2 is omitted, and the syringe 90 can be attached more easily. Further, since the width of the syringe 90 is reduced, even an operator with small hands can easily grasp the syringe 90. Further, since both side surfaces in the width direction are flat, when placed on a flat surface such as a table, rolling of the syringe 90 can be suppressed.

[0049] Furthermore, in the height direction (depth direction), since the distance and the contact area with the holding portion 73 increase, the chemical solution can be injected stably. That is, both side surfaces (inner surfaces) in the width direction of the syringe 90 function as fixed guides for guiding the gasket 100. Therefore, when the gasket 100 slides, rotation of the gasket 100 or the suction cup 120 with respect to the cylinder 91 due to the sliding resistance during injection can be suppressed. Thereby, distortion of the gasket 100 that causes backflow can be suppressed, and the forward and backward movement by the ram 110 can be performed stably. Further, since the flange 92 can be made smaller, the material can be reduced during the manufacture of the cylinder 91, and the cost can be reduced.

[0050] Also, since the diameters of the syringe 90 are different in the height direction and the width direction, the operator can visually recognize the orientation and the attachment / detachment direction of the syringe 90. Further, by attaching a scale to the upper surface of the cylinder 91, the portion with the scale is located above the holder 7 or the adapter 8. Therefore, it becomes easier for the operator to see the scale. Furthermore, when air enters the cylinder 91, the air accumulates in the upper space inside the cylinder 91, so the air stays at a position farther from the tip 93, and the outflow to the patient side is suppressed.

[0051] [Second Embodiment] In the first embodiment, the gasket 100 includes a sealing member 140 and a suction cup 120. On the other hand, in the second embodiment, the gasket 200 is different from the first embodiment in that the gasket 200 includes a suction cup 220 and an O-ring 230. Hereinafter, the second embodiment will be described with reference to FIG. 10. In the description of the second embodiment, the differences from the first embodiment will be described, and the same reference numerals will be assigned to the components described in the first embodiment, and the description thereof will be omitted. Unless otherwise specified, the components with the same reference numerals exhibit substantially the same operations and functions, and their effects are also substantially the same.

[0052] FIG. 10 is a schematic cross-sectional view of the gasket 200 along the front-rear direction and the height direction. The gasket 200 has a suction cup 220 having a tip portion with an elliptical cross-sectional shape, and an O-ring 230 fitted to the suction cup 220. This O-ring 230 is housed in an annular O-ring groove 223 formed on the peripheral surface of the suction cup 220. And when this O-ring 230 abuts on the inner surface of the cylinder 91, the cylinder 91 is sealed. Alternatively, two or more O-rings 230 may be provided. In this case, two or more O-ring grooves 223 are formed.

[0053] Further, the suction cup 220 has a plurality of engaging claws 222 and an annular groove 225 formed between the engaging claws 222 and the O-ring groove 223. In order to facilitate the displacement of the engaging claws 222, the portion where the annular groove 225 is formed is thinner than other portions. A substantially fan-shaped recess 229 is formed in each engaging claw 222. By means of the recess 229, the thickness of the engaging claw 222 can be reduced. Therefore, the engaging claw 222 is more easily deformed.

[0054] In the central portion surrounded by the engaging claws 222, a hole H having a shape that narrows toward the bottom is formed. When the ram 110 is inserted into this hole H, the end face of the front end portion 111 of the ram 110 abuts against the bottom of the hole H. And in the state where the end face of the front end portion 111 abuts against the bottom of the hole H, a gap is generated between the outer surface of the front end portion 111 and the inner surface S of the hole H. Therefore, the front end portion 111 inserted into the hole H is guided to slide on the inner surface S inclined toward the center of the bottom. Thereby, the front end portion 111 can be aligned with the center of the hole H. A gap is formed between adjacent engaging claws 222, and when the gasket 200 advances the cylinder 91, each engaging claw 222 is displaced so that the adjacent engaging claws 222 approach each other. The gaps between the engaging claws 222 all have the same length. Thereby, it is possible to suppress fluctuations in the position of each engaging claw 222 with respect to the ram 110 during displacement.

[0055] Each engaging claw 222 is provided with a protrusion 224 that engages with the engaging groove 112 of the ram 110. The tip of this protrusion 224 is rounded so as to be easily inserted into the engaging groove 112 of the ram 110. The gasket 200 of the second embodiment has, similarly to the first embodiment, an inner surface S that defines a hole H with an enlarged diameter at the entrance, and an annular groove 225 that serves as a starting point of deformation. Further, the engaging claw 222 has a ridge 228 that protrudes outward. And when the gasket 200 is assembled to the cylinder 91, the ridge 228 is received by the enlarged diameter portion 94 of the cylinder 91, and the entire gasket 200 is accommodated in the cylinder 91.

[0056] When connecting the ram 110 and the gasket 200, the ram 110 is inserted into the hole H, and the end face of the front end portion 111 of the ram 110 abuts against the bottom of the hole H. Then, when the ram 110 pushes the gasket 200, the gasket 200 advances in the cylinder 91. When the gasket 200 advances, the ridge 228 of the engaging claw 222 abuts against the enlarged diameter portion 94. And as it advances, the ridge 228 passes through the enlarged diameter portion 94, and the engaging claw 222 is displaced toward the perpendicular line P. At this time, the engaging claw 222 deforms starting from the center of the bottom of the annular groove 225.

[0057] As a result, even if the front end portion 111 is inserted at a position offset with respect to the perpendicular line P within the hole H, the front end portion 111 is displaced so that the central axis of the front end portion 111 aligns with the perpendicular line P. Therefore, it is possible to suppress the central axis of the front end portion 111 from tilting with respect to the gasket 200. When the protrusion 228 passes through the enlarged diameter portion 94, the engaging claws 222 narrow. Then, the protrusion 224 of the engaging claw 222 at the narrowed position enters into the engaging groove 112 of the ram 110, and the protrusion 224 engages with the engaging groove 112. As a result, the gasket 200 is connected to the ram 110. Further, as the engaging claw 222 is displaced, the annular groove 225 deforms so as to widen.

[0058] After that, when the gasket 200 advances within the cylinder 91, the sucker 220 presses the chemical solution within the cylinder 91. As a result, the chemical solution is extruded from the tip portion 93. After the injection of the chemical solution, the ram 110 retracts, and the gasket 200 connected to the ram 110 also retracts. Then, when the ram 110 and the gasket 200 retract to a position where the protrusion 228 is received by the enlarged diameter portion 94, the engaging claws 222 spread outward, and the protrusion 224 of the displaced engaging claw 222 disengages from the engaging groove 112.

[0059] Further, as the engaging claw 222 is displaced, the annular groove 225 narrows so as to return to its original shape. When the ram 110 further retracts, the gasket 200 stays within the cylinder 91 due to the frictional force between the O-ring 230 and the cylinder 91. As a result, the ram 110 disengages from the gasket 200 and retracts to the position before insertion.

[0060] Also, with the ram 110 and the gasket 200 according to such a second embodiment as well, the engaging claws 222 deform starting from the center of the bottom of the annular groove 225. Therefore, the plurality of engaging claws 222 are evenly displaced toward the perpendicular line P of the sucker 220. As a result, when the ram 110 disengages from the gasket 200, it is possible to suppress the front end portion 111 from being located at a position offset with respect to the perpendicular line P. Therefore, it is possible to prevent the engaging groove 112 of the front end portion 111 from being caught by the protrusion 224.

[0061] Also, according to the ram 110 and the gasket 200 according to the second embodiment, when connecting the gasket 200 and the ram 110, it is possible to suppress rattling of the ram 110 with respect to the gasket 200. Furthermore, since the gasket 200 and the ram 110 are directly connected, the distance between the syringe 90 and the pressing portion 4 can be shortened. Therefore, the size of the injection head 2 in the injection system 1 can be reduced. Furthermore, since the size in the width direction can be reduced, a syringe 90 with the same capacity and a smaller size can be formed. As a result, the injection head 2 can be miniaturized and lightened.

[0062] As described above, the present invention has been described with reference to each embodiment, but the present invention is not limited to the above embodiments. Inventions modified within the scope not contrary to the present invention, and inventions equivalent to the present invention are also included in the present invention. In addition, each of the above-described embodiments and modifications can be appropriately combined within the scope not contrary to the present invention.

[0063] For example, notches or holes may be formed in the engaging claws 122, 222. As a result, since the portion where the notch or hole is formed is deformed, the engaging claws 122, 222 are likely to be displaced. Also, the inner surface S of the gaskets 100, 200 may be divided into two surfaces with different inclinations. Further, the inner surface S may constitute a continuous inclined surface or a curved surface. Furthermore, the gaskets 100, 200 may have an oval outer shape in which the length in the height direction is longer than the length in the width direction perpendicular to the height direction. In this case, the cylinder 91 has a shape complementary to the oval outer shape.

[0064] In addition, the syringe 90 filled with the liquid medicine may be a prefilled syringe. Also, the liquid medicine may be manually filled into the syringe 90, or may be filled into the syringe 90 by the injection head 2 or a filler. Further, the syringe 90 can be provided with a data carrier such as an RFID or a barcode. Information on the filled liquid medicine is recorded in this data carrier. Then, the injection system 1 can read the information recorded from the data carrier via the injection head 2 and control the injection amount of the liquid medicine. For example, the control device can calculate the optimal injection amount per body weight based on the read information (iodine amount) of the liquid medicine and display it on the touch panel of the console. When filling the empty syringe 90 with the liquid medicine, the liquid medicine may be aspirated from a large-capacity bottle provided with a data carrier. Thereby, the amount of the liquid medicine in the large-capacity bottle can be monitored, and the liquid medicine can be injected multiple times. Also, the information on the liquid medicine recorded in the data carrier of the large-capacity bottle may be read and written to an RFID tag or the like of the empty syringe 90. Further, the read information may be used for the setting in the injection head 2.

[0065] Furthermore, a notch may be formed in a part of the outer periphery of the flange 92. Specifically, the flange 92 may have two arc portions that are arc-shaped with respect to the central axis of the syringe 90, and two flat portions that are formed between the arc portions and face each other. In this case, the adapter 8 can be provided with, for example, a locking claw, a convex portion, or a latch as an engaging portion that engages with the notch.

[0066] Further, instead of forming the enlarged diameter portion 94 in the cylinder 91, a skirt portion extending rearward from the flange 92 may be formed. The inner surface of this skirt portion is inclined and receives the ridge 128 of the engaging claw 122 so as to be located at the position where the engaging claw 122 spreads. Therefore, the inner dimension of the skirt portion is set to match the outer dimension of the engaging claw 122 in the spread state. That is, the skirt portion has a shape that narrows toward the tip portion 93. As a result, the engaging claw 122 of the gasket 100 inserted inside the skirt portion does not displace to the narrowed position. Or, even when the engaging claw 122 is slightly displaced, the interval between the opposing protrusions 124 can maintain a state where the ram 110 can be inserted.

[0067] In this case, after the insertion of the front end portion 111 of the ram 110, when the ram 110 presses the gasket 100, the gasket 100 advances inside the cylinder 91. When the gasket 100 advances, the ridge 128 of the engaging claw 122 passes through the skirt portion and abuts against the inner surface of the cylinder 91. Then, as it advances, due to the reaction force from the inner surface of the cylinder 91, the engaging claw 122 displaces toward the center of the hole H of the sucker 120.

[0068] Further, instead of forming the enlarged diameter portion 94 in the cylinder 91, the rear portion of the gasket 100 may be projected outward from the cylinder 91. In this case, when the ram 110 presses the gasket 100, the gasket 100 advances inside the cylinder 91. When the gasket 100 advances, the ridge 128 of the engaging claw 122 gets over the rear end of the cylinder 91 and abuts against the inner surface of the cylinder 91. Then, when the ridge 128 gets over the rear end of the cylinder 91, due to the reaction force from the inner surface of the cylinder 91, the engaging claw 122 displaces toward the perpendicular line P of the sucker 120.

[0069] Some or all of the above embodiments may be described as follows in the appended claims, but are not limited thereto.

[0070] [Appended Claim 1] A plurality of engaging claws including an inner surface defining a hole with a widened diameter at the entrance and a protrusion protruding in a direction away from a perpendicular line passing through the center of the hole, the engaging claws being displaceable between an expanded position and a narrowed position, and a gasket having the engaging claws; A ram inserted into the hole so as to engage with the engaging claw; A cylinder into which the gasket is inserted, the cylinder abutting against the protrusion of the engaging claw of the gasket after insertion; An injection device configured to advance the ram and inject a chemical solution into the cylinder; An injection system, in which an annular groove serving as a starting point for deformation of the engaging claw is formed in the gasket.

[0071] [Appendix 2] The injection system according to Appendix 1, wherein a diameter-expanded portion for receiving the protrusion is formed at a rear end portion of the cylinder.

[0072] This application claims priority from Japanese Patent Application No. 2018-200114 filed on October 24, 2018, the entire contents of which are incorporated herein by reference and made a part of this application.

Explanation of Reference Numerals

[0073] 1: Injection system, 2: Injection device, 91: Cylinder, 100: Gasket, 110: Ram, 200: Gasket

Claims

1. a gasket including a plurality of engaging claws and a tip portion having an elliptical cross-sectional shape whose height direction is longer than its width direction perpendicular to the height direction; a ram engaging the gasket; a cylinder into which the gasket is inserted; an injection device configured to advance the ram and configured to inject a chemical solution in the cylinder; An injection system wherein the plurality of engaging claws are displaceable between a widened position and a narrowed position, define a hole with an enlarged entrance diameter, and include an inner surface that slopes away from a perpendicular line passing through the center of the hole, and among the plurality of engaging claws, two of the engaging claws aligned in the height direction have the same shape and size, and two of the engaging claws aligned in the width direction have the same shape and size.

2. Each of the plurality of engagement claws includes a protrusion protruding in a direction away from the perpendicular line, The injection system according to claim 1 , wherein the rear end of the cylinder is formed with an enlarged diameter portion that receives the protrusion.

3. The injection system according to claim 1 or 2, wherein the gasket is formed with an annular groove that serves as a starting point for deformation of the engagement claw.

4. a gasket including a plurality of engaging claws and a tip portion having an elliptical cross-sectional shape whose height direction is longer than its width direction perpendicular to the height direction; a cylinder into which the gasket is inserted; A syringe in which the plurality of engaging claws are displaceable between a widened position and a narrowed position, define a hole with an enlarged diameter at the entrance, and include an inner surface that slopes away from a perpendicular line passing through the center of the hole, and among the plurality of engaging claws, two of the engaging claws aligned in the height direction have the same shape and size, and two of the engaging claws aligned in the width direction have the same shape and size.

5. a plurality of engaging claws; and a tip portion having an elliptical cross-sectional shape whose height direction is longer than its width direction perpendicular to the height direction, A gasket wherein the plurality of engaging claws are displaceable between a widened position and a narrowed position, define a hole with an enlarged entrance, and include an inner surface that slopes away from a perpendicular line passing through the center of the hole, and among the plurality of engaging claws, two of the engaging claws aligned in the height direction have the same shape and size, and two of the engaging claws aligned in the width direction have the same shape and size.

Images