Drug solution injection device

Abstract

To provide a drug solution injection device on which three syringes can be mounted and that is compact. This drug solution injection device for injecting drug solutions is characterized by comprising: three syringe holders on which syringes are mounted and that are arranged so as to have a triangular positional relationship in a cross-section perpendicular to the direction of the axes of the syringes; three plungers that, with respect to each of the three syringes respectively, press the piston of the mounted syringe in the axial direction of the syringe; and three motors that drive each of the three plungers respectively.

Description

Chemical injection device

[0001] The present invention relates to a chemical liquid injector.

[0002] Currently, medical fluoroscopic imaging devices include devices such as CT (Computed Tomography) scanners, MRI (Magnetic Resonance Imaging) devices, PET (Positron Emission Tomography) devices, ultrasound diagnostic devices, CT angiography devices, MR angiography devices, and angiography devices. When using these devices, multiple types of medicinal liquids are injected into the patient's body for the purpose of obtaining clear images, etc. Therefore, for example, when injecting a contrast medium and physiological saline, a medicinal liquid injector equipped with two syringes is used.

[0003] Patent Document 1 discloses an apparatus in which two syringes filled with an injection contrast medium and a physiological saline solution are set on an injection head that controls the pushing drive of the pistons of the two syringes, and the injection amount of each is controlled while the injection is performed into a patient through an indwelling needle inserted into the patient's blood vessel.

[0004] Japanese Patent Application Laid-Open No. 2005-021495

[0005] During a procedure in which a medicinal liquid is injected into a patient's body, when it is necessary to switch between different contrast agents and inject the medicinal liquid, an injection device capable of mounting three or more syringes is required. However, arranging three syringes in a horizontally parallel arrangement, as in the device disclosed in Patent Document 1, is undesirable because it increases the device's horizontal size. Furthermore, an injection device equipped with three syringes requires a larger, stronger stand to maintain horizontal weight balance regardless of fluctuations in the remaining amount of medicinal liquid in the syringes, which may result in an increase in the device's size.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a compact liquid injector that can accommodate three syringes.

[0007] In order to solve the above problems, the chemical liquid injection device of the present invention is a chemical liquid injection device that injects a chemical liquid, and is characterized by having three syringe holders to which syringes are attached and arranged in a triangular positional relationship in a cross section perpendicular to the axial direction of the syringes, three plungers that press the pistons of the attached syringes in the axial direction of the syringes for each of the three syringe holders, and three motors that drive each of the three plungers.

[0008] According to the present invention, it is possible to provide a compact liquid injector that can be fitted with three syringes.

[0009] FIG. 1 is a schematic diagram of a chemical liquid injection system using a chemical liquid injector of the present invention. FIG. 1 is a perspective view of the chemical liquid injector of Example 1 with a syringe attached. FIG. 2 is a perspective view of the chemical liquid injector of Example 1. FIG. 3 is a perspective view of the chemical liquid injector of Example 1 with a syringe attached. FIG. 4 is a front view of the chemical liquid injector of Example 1 with a syringe attached. FIG. 5 is a front view of the chemical liquid injector of Example 1 with a syringe attached and in a syringe replacement position. FIG. 6 is a partially enlarged perspective view of the chemical liquid injector of Example 1 at the syringe replacement position. FIG. 7 is a perspective view of the chemical liquid injector of Example 2 with a syringe attached. FIG. 8 is a perspective view of the chemical liquid injector of Example 2 at the syringe replacement position with a syringe attached, and with the third syringe holder in a front position. FIG. 9 is a front view of the chemical liquid injector of Example 2 at the syringe replacement position with a syringe attached. FIG. 10 is a perspective view of the chemical liquid injector of Example 2 with the third syringe holder in a rear position.

[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, relative positions of components, etc. 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 forms specifically described in the following embodiments.

[0011] Fig. 1 is a schematic diagram of an imaging system 10 using a chemical liquid injector 30 according to this embodiment. Fig. 2 is a schematic perspective view of the chemical liquid injector 30 according to this embodiment. Although the chemical liquid injector 30 is attached to a stand 35 as shown in Fig. 1, this is merely an example, and the chemical liquid injector 30 may also be attached to a ceiling suspension device.

[0012] 1 , imaging system 10 includes a liquid injector 30 that injects a contrast agent, and an imaging device 20 that is connected to liquid injector 30 by wire or wirelessly and that images a subject. Examples of imaging device 20 include various medical imaging devices, such as an MRI device, a CT device, an angio imaging device, a PET 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. A CT device will be described below.

[0013] The imaging device 20 has an imaging unit 21 that images a subject according to an imaging plan, and a control device 40 that controls the entire imaging device 20. This imaging plan includes information such as the imaging region, effective tube voltage, model name, manufacturer name, imaging time, tube voltage, imaging range, rotation speed, helical pitch, exposure time, dose, and imaging method. The control device 40 then controls the imaging unit 21 to image the subject in accordance with the imaging plan. The control device 40 can also communicate with the imaging unit 21, the liquid injector 30, and a server (external storage device) via wired or wireless communication.

[0014] The imaging unit 21 includes a bed, an X-ray source that irradiates the subject with X-rays, and an X-ray detector that detects the X-rays that have passed through the subject. The imaging unit 21 exposes the subject to X-rays and captures a fluoroscopic image of the subject by back-projecting the inside of the subject's body based on the X-rays that have passed through the subject. Alternatively, the imaging unit 21 may capture images using radio waves or ultrasound.

[0015] The imaging device 20 also has a display 43 as a display unit. This display 43 is connected to the control device 40 and displays the input status, setting status, imaging results, and various information of the device. Alternatively, the control device 5 and the display 43 can be configured as an integrated unit. Furthermore, the imaging device 20 has a user interface such as a keyboard as an input unit 44. A user can input drug solution information, imaging information, subject information, and / or imaging conditions to the imaging device 20 from the input unit 44.

[0016] The liquid injector 30 injects a liquid medicine, such as physiological saline and various contrast agents, filled in a syringe into a subject. This injection protocol includes at least an injection rate and an injection time. The injection protocol may also include information on injection conditions such as injection rate acceleration, injection amount, injection timing, contrast agent concentration, and injection pressure. The liquid injector 30 injects the contrast agent according to the final injection protocol. The syringe 201 filled with the liquid medicine is then mounted on the liquid injector 30. The liquid injector 30 also includes a stand 35 and a console 41 connected by wire or wirelessly.

[0017] The console 41 functions as a control device that controls the liquid injector 30 and also as a generator that generates an injection protocol for a contrast agent. The console 41 includes a touch panel 42 that functions as an input / display unit and is capable of wired or wireless communication with the liquid injector 30 and the imaging device 20. The touch panel 42 displays the injection protocol, the input status of the device, the setting status, the injection results, and various information. Instead of the touch panel 42, the liquid injector 30 may include a display as a display unit and a user interface such as a keyboard as an input unit.

[0018] Instead of the console 41, the liquid injector 30 may include a control device connected to the liquid injector 30 and a display unit (e.g., a touch panel display) connected to the control device that displays the liquid injection status. This control device also functions as an injection protocol generator. The liquid injector 30 and the control device may be integrated with a stand 35. Furthermore, instead of the stand 35, a ceiling suspension member may be provided, and the liquid injector 30 may be suspended from the ceiling via the ceiling suspension member.

[0019] The liquid injector 30 may also have a remote control device (e.g., a hand switch) for remote operation. This remote control device can remotely control the liquid injector 30 to start or stop injection. The liquid injector 30 may also have a power source or battery. This power source or battery can be provided in either the liquid injector 30 or the control device, or can be provided separately.

[0020] The liquid injector 30 has a syringe holder 302 on which a syringe is mounted, and a built-in drive mechanism that pushes out the liquid in the syringe according to an injection protocol. The liquid injector 30 also has an operation unit (not shown) for inputting the operation of the drive mechanism. The operation unit is provided with, for example, a drive mechanism forward button, a drive mechanism reverse button, and a final confirmation button. The liquid injector 30 may also have a head display that displays the injection conditions, injection status, device input status, setting status, and various injection results.

[0021] When the contrast medium is to be injected, a piping system 100, such as an extension tube, is connected to the tip of a syringe mounted on chemical liquid injector 30. Then, when preparations for injection are complete, the user presses a final confirmation button on the operation unit. This places chemical liquid injector 30 in a standby state ready to start injection. When injection begins, the contrast medium is pushed out of the syringe and injected into the subject's body via the extension tube.

[0022] The liquid injector 30 can be equipped with various syringes, including pre-filled syringes with data carriers such as RFID chips, IC tags, or barcodes. The liquid injector 30 also includes a built-in reader that reads the data carriers attached to the syringes. This data carrier stores information related to the liquid (liquid information). The liquid information includes product ID, product name, chemical classification, ingredients, contrast agent concentration, viscosity, expiration date, syringe capacity, syringe pressure resistance, cylinder inner diameter, piston stroke, and lot number.

[0023] The liquid injector 30 can receive information from and transmit information to a server (external storage device) (not shown). The imaging device 20 can also receive information from and transmit information to a server. This server can be, for example, a Radiology Information System (RIS), a Picture Archiving and Communication System (PACS), or a Hospital Information System (HIS).

[0024] The server stores test orders in advance. These test orders include information about the subject (subject information) and information about the test contents (test information). The subject information includes the subject's weight, lean body mass, circulating blood volume, subject ID, name, sex, date of birth, age, height, blood volume, body surface area, illnesses, heart rate, cardiac output, hemoglobin (g / dL), blood flow velocity, side effect history, and creatinine level. The test information includes the test number (test ID), test site, test date and time, medicinal solution type, medicinal solution name, and imaging information (information about the imaged site). The server can also store information about imaging results, such as image data transmitted from the imaging device 20, and information about injection results transmitted from the injection device 1. An external imaging system or an imaging workstation can also be used to operate the injection device 1 and the imaging device 20.

[0025] The chemical liquid injection system 1 includes a chemical liquid injection device 30 for injecting a chemical liquid such as a contrast agent into a patient, a first syringe 201A, a second syringe 201B, and a third syringe 201C attached to the chemical liquid injection device 30, and a piping system 100 connected to each syringe.

[0026] In this embodiment, first syringe 201A and second syringe 201B are filled with contrast medium, and third syringe 201C is filled with physiological saline. First syringe 201A, second syringe 201B, and third syringe 201C may be prefilled syringes filled with medicinal liquid in advance, or may be suction syringes that suction medicinal liquid from a medicinal liquid bag, i.e., so-called multi-use syringes. In this embodiment, all three syringes will be described as prefilled syringes.

[0027] Specific examples of contrast agents include a contrast agent with an iodine concentration of 240 mg / ml (e.g., viscosity 3.3 Pa·s, specific gravity 1.268-1.296 at 37°C), a contrast agent with an iodine concentration of 300 mg / ml (e.g., viscosity 6.1 mPa·s, specific gravity 1.335-1.371 at 37°C), and a contrast agent with an iodine concentration of 350 mg / ml (e.g., viscosity 10.6 mPa·s, specific gravity 1.392-1.433 at 37°C). Specific examples of saline include saline containing 180 mg of sodium chloride in 20 mL of saline (e.g., viscosity 0.9595 mPa·s, specific gravity 1.004-1.006 at 20°C).

[0028] The contrast agents filled in first syringe 201A and second syringe 201B may be the same or different from each other. It should be noted that the present invention is not limited by the type of medicinal liquid filled in the three syringes.

[0029] Liquid injector 30 is rotatably held on the upper part of movable stand 35 placed on the floor surface, so that liquid injector 30 can be rotated between a position where the leading end side (+X direction side) of liquid injector 30 faces the floor surface and a position where the trailing end side (-X direction side) of liquid injector 30 faces the floor surface.

[0030] FIG. 2 is a perspective view of chemical liquid injector 30. FIG. 2 shows the state in which the housing cover is removed from chemical liquid injector 30 shown in FIG. 1 and first syringe 201A, second syringe 201B, and third syringe 201C are attached to chemical liquid injector 30. To facilitate the description of the invention, the coordinate axes shown in the figure are such that the X direction corresponds to the linear motion direction of a plunger device (described later) (the direction in which the piston pushes into the syringe). The Y direction is perpendicular to the X direction and indicates the direction in which a first unit and a second unit (described later) are arranged. The Z direction is perpendicular to the X and Y directions. In normal use of chemical liquid injector 30 of the present invention, the Y direction corresponds to the horizontal direction, and the Z direction corresponds to a direction having a vertically upward component.

[0031] The liquid injector 30 of this embodiment is configured to accommodate syringes whose cross section perpendicular to the axial direction is elliptical, with the minor axis extending in the horizontal direction (Y direction) in which the two syringes are aligned. However, the present invention is not limited to this configuration, and the liquid injector 30 may be configured to accommodate syringes whose cross section perpendicular to the axial direction is circular.

[0032] The tips of the first syringe 201A, the second syringe 201B, and the third syringe 201C are connected to the piping system 100. The first syringe 201A, the second syringe 201B, and the third syringe 201C are connected to the first, second, and third tubes 101, 102, and 103, respectively. The first and second tubes 101 and 102 are connected to a first mixer 105 formed of a T-shaped joint, a Y-shaped joint, or the like, and the first mixer 105 is connected to a fourth tube 104. The third and fourth tubes 103 and 104 are connected to a second mixer 106 formed of a T-shaped joint, a Y-shaped joint, or the like, and the second mixer 106 is connected to a fifth tube 107. The fifth tube 107 is in communication with a catheter 109 via a catheter hub 108 or the like.

[0033] In addition, a piston (not shown) is attached to each of first syringe 201A, second syringe 201B, and third syringe 201C. With the pistons attached, first syringe 201A, second syringe 201B, and third syringe 201C are held in first, second, and third syringe holders 302A, 302B, and 302C of liquid injector 30.

[0034] Liquid injector 30 includes first, second, and third syringe pressers 313A, 313B, and 313C. First, second, and third syringe pressers 313A, 313B, and 313C abut against rear ends of pistons attached to first syringe 201A, second syringe 201B, and third syringe 201C, respectively, and operate to push the pistons into the syringes. First, second, and third syringe pressers 313A, 313B, and 313C are configured to engage with rear ends of the pistons of first, second, and third syringes 201A, 201B, and 201C, respectively, and may be capable of suctioning liquid from a liquid injector bag using a multi-use syringe.

[0035] During injection of a liquid medicine, tubes are attached to the conduits at the tips of first syringe 201A, second syringe 201B, and third syringe 201C, respectively, and a piston is advanced in the axial direction of each syringe by a syringe presser. This pushes out the liquid medicine, such as contrast medium and / or physiological saline, from each syringe. Note that first, second, and third plunger devices 301A, 301B, and 301C that drive the three syringe pressers can be driven independently or simultaneously.

[0036] The extruded contrast medium and medicinal liquids such as saline flow into the first to third tubes 101, 102, and 103, and if medicinal liquids are extruded from multiple syringes at the same time, they are mixed and injected into the patient's blood vessels via catheter 109.

[0037] When using a multi-use syringe that aspirates medicinal liquid from a medicinal liquid bag, suction tubes for filling are attached to the conduits at the tips of first syringe 201A and second syringe 201B, and the medicinal liquid is filled from the medicinal liquid bag via these suction tubes. At this time, the syringe presser advances the piston in the axial direction of the suction-type syringe that aspirates medicinal liquid to the tip of the syringe, and then retracts it to the rear end of the syringe.

[0038] Furthermore, a backflow prevention mechanism, such as a check valve, for preventing flow toward the syringes may be provided at the tips of first syringe 201A, second syringe 201B, and third syringe 201C and / or in the piping system up to fifth tube 107. This backflow prevention mechanism prevents flow from the tube side to the syringe side. In other words, it is possible to prevent air, medicinal solution, the patient's blood, and the like from flowing into first syringe 201A, second syringe 201B, and third syringe 201C from catheter 109.

[0039] Before the injection of the liquid medicine, priming may be performed to remove air. There are several methods for this priming, and the inside of the piping system 100 is filled with either physiological saline or a contrast medium.

[0040] Fig. 2 shows a perspective view of chemical liquid injector 30 of Example 1 when three syringes are attached, as viewed from the oblique front, and Fig. 4 shows a perspective view of chemical liquid injector 30 of Example 1 when three syringes are attached. Fig. 3 shows a perspective view of chemical liquid injector 30 of Example 1 when no syringes are attached, as viewed from the oblique front. Fig. 5 shows a front view of chemical liquid injector 30 of Example 1 when three syringes are attached.

[0041] Liquid injector 30 includes first, second, and third units that can independently control the pushing of the pistons of three syringes 201A, 201B, and 201C, respectively.

[0042] The first unit includes a first syringe holder 302A, a first plunger device 301A, and a first motor 304A (not shown). The first syringe holder 302A holds the first syringe 201, and the first plunger device 301A is a rotary-to-linear motion conversion mechanism and includes a syringe presser 313A that pushes out the piston of the first syringe. The first motor 304A is a drive source for the rotational force of the first plunger device 301A. Similarly, the second unit includes a second syringe holder 302B, a second plunger device 301B, and a second motor 304B, and the third unit includes a third syringe holder 302C, a third plunger device 301C, and a third motor 304C.

[0043] The first motor 304A is disposed vertically below (in the -Z direction) the first plunger device 301A. As shown in FIG. 4 , at the rear (in the -X direction) of the liquid injector 30, the shaft of the first motor 304A and the shaft of the first plunger device 301A are connected by a transmission mechanism 305A, and the rotational force of the first motor 304A is transmitted to the first plunger device 301A. In this embodiment, the transmission mechanism 305A is configured with gears and a timing belt, but the present invention is not limited to this configuration and may be configured with, for example, a gear system. The shaft of the second motor 304B and the shaft of the second plunger device 301B are connected by a transmission mechanism 305B, and the rotational force of the second motor 304B is transmitted to the second plunger device 301B. The second motor 304B is disposed vertically below (in the -Z direction) the second plunger device 301B. The shaft of the third motor 304C and the shaft of the third plunger device 301C are connected by a transmission mechanism 305C, and the rotational force of the third motor 304C is transmitted to the third plunger device 301C. The third motor 304C is disposed vertically above the third plunger device 301C (in the +Z direction). This arrangement of the plunger devices and motors makes it possible to configure a compact device with a compact horizontal size, even though it is a device that drives and operates three plungers.

[0044] In this embodiment, the motor, which is the drive unit, is arranged on the upper or lower side of the plunger device, but the present invention is not limited to this configuration, and the motor may be connected coaxially to the rear side of the plunger device in the axial direction (-X direction side).

[0045] First syringe holder 302A has a first receiving portion 310A that receives flange 202A of first syringe 201A. First syringe 201A is attached to first syringe holder 302A by flange 202A sliding relative to first receiving portion 310A in a direction perpendicular to the axial direction (X direction). Second syringe holder 302B similarly has a second receiving portion 310B that receives flange 202B of second syringe 201B. Second syringe 201B is attached to second syringe holder 302B by flange 202B sliding relative to second receiving portion 310B in a direction perpendicular to the axial direction (X direction). Third syringe holder 302C has a third receiving portion 310C that receives flange 202C of third syringe 201C. Flange 202C slides relative to third receiving portion 310C in a direction perpendicular to the axial direction (X direction), whereby third syringe 201C is attached to third syringe holder 302C.

[0046] Third syringe holder 302C is located vertically below first and second syringe holders 302A and 302B (in the -Z direction). Therefore, in the state shown in FIGS. 1 and 2 (the injectable position), it is not possible to ensure sufficient space for moving third syringe 201C from a direction perpendicular to the axial direction in order to attach flange 202C to third receiving portion 310C. In contrast, as shown in FIG. 6 , liquid injector 30 of the present invention has a configuration in which first receiving portion 310A and second receiving portion 310B are each rotatable about rotation axes (first rotation axis 309A and second rotation axis 309B) parallel to the extrusion direction of the plunger device. The first and second rotation axes 309A and 309B are located on either side of the two axes of the first plunger device 301A and the second plunger device 301B corresponding to the first and second syringe holders 302A and 302B, respectively, in a direction connecting the two axes.

[0047] First and second receiving portions 310A and 310B can be rotated around first and second rotation shafts 309A and 309B in directions away from each other (first receiving portion 310A in the −Y direction, second receiving portion 310B in the +Y direction) to a fan-shaped, spread-out state (syringe exchange position). This ensures space for moving third syringe 201C from the top (+Z direction side) of third syringe holder 302C downward (−Z direction) to attach and detach it to and from third syringe holder 302C. With first and second syringe holders 302A and 302B rotated to the syringe exchange position, third syringe 201C can be attached and detached to and from third syringe holder 302C through the gap between first and second syringe holders 302A and 302B.

[0048] The operator can rotate the first and second syringe holders 302A and 302B by grasping the handles 311A ​​and 311B of the first and second syringe holders 302A and 302B, respectively. The first and second syringe holders 302A and 302B are provided with recesses 312A and 312B that engage with protrusions (not shown) on the opposing surfaces of the third syringe holder 302C, which serves as a fixing portion, when the first and second syringe holders 302A and 302B are in the injection position. This allows the operator to position the first and second receiving portions 310A and 310B in the injection position when rotating the first and second receiving portions 310A and 310B to the injection position. The operator can also confirm that the first and second receiving portions 310A and 310B have been reliably positioned in the injection position by the clicking sound (sound) generated when the protrusions engage with the recesses 312A and 312B. Here, the protrusions (not shown) that engage with the recesses 312A and 312B may be expandable protrusions, or may be fixed convex portions that snap into engagement with the recesses 312A and 312B.

[0049] In the first and second syringe holders 302A and 302B, the first and second receiving portions 310A and 310B for receiving the flanges 202A and 202B of the first and second syringes 201A and 201B have tapered openings that widen in the axial direction (X direction). This configuration facilitates the operation of receiving the syringes (FIG. 7).

[0050] The liquid medicine injection device 30 of this embodiment can be equipped with three syringes, but can also be used with only one or two syringes attached, and any of the three syringe holders can be selected to attach and use a syringe.

[0051] The liquid injector 30 of this embodiment is configured to mount syringes whose cross section perpendicular to the axial direction is elliptical, with the minor axis extending horizontally (in the Y direction) along which the two syringes are aligned. This configuration prevents the liquid injector 30 from expanding horizontally, makes it easier to balance the weight horizontally regardless of fluctuations in the amount of liquid remaining in the syringes, and eliminates the need for a larger, stronger stand, thereby preventing the device from becoming larger.

[0052] As described above, the liquid injector 30 of this embodiment can accommodate three syringes while suppressing the horizontal expansion of the device, thereby providing a compact liquid injector.

[0053] 8 to 11, a chemical liquid injector 30 of Example 2 will be described. In Example 1, a chemical liquid injector 30 to which a syringe with a short piston handle is attached is exemplified. The chemical liquid injector 30 of Example 2 differs from Example 1 in that it is configured to be able to attach a syringe with a long piston handle, but other basic configurations are the same as those of Example 1. In the following description of the chemical liquid injector 30 of Example 2, configurations that differ from Example 1 will be mainly described, and configurations that are the same as those of Example 1 will be omitted.

[0054] Fig. 8 is a perspective view of the liquid injector 30, seen obliquely from the front, with the first and second syringe holders 302A, 302B in the injection positions and the third syringe holder 320 in the extended position. Fig. 9 is a perspective view of the liquid injector 30, seen obliquely from the front, with the first and second syringe holders 302A, 302B in the syringe replacement positions and the third syringe holder 320 in the forward position. Fig. 10 is a front view of the liquid injector 30, seen obliquely from the front, with the first and second syringe holders 302A, 302B in the syringe replacement positions. Fig. 11 is a perspective view of the liquid injector 30, seen obliquely from the front, with the first and second syringe holders 302A, 302B in the injection positions and the third syringe holder 320 in the rear position.

[0055] Third syringe 220 attached to chemical solution injector 30 of Example 2 is a syringe having a circular shape in a cross section perpendicular to the axial direction. Third syringe 220 is attached to third syringe holder 320 with third syringe 220 positioned in the axial direction by inserting flange 222 into third receiving portion 321 of third syringe holder 320 perpendicular to the axial direction.

[0056] Two support rods 322 extending axially rearward (-X direction) are fixed to the third syringe holder 320 at positions on both sides of the third syringe 220 in the Y direction. The support rods 322 are inserted and supported by a support portion 323 of the main body of the chemical liquid injector 30 so as to be slidable in the axial direction. The end of each support rod 322 opposite the third syringe 220 is fixed to a flange 324. The flange 324 defines the mechanical movement limit when the support rods 322 slide relative to the support portion 323 and the third syringe holder 320 extends (moves in the +X direction). The third syringe holder 320, which is movable by the sliding of the support rods 322, has a structure (not shown) that fixes the X-direction position of the third syringe holder 320 at any position. That is, the axial position of the third syringe holder 320 relative to the corresponding third plunger device 301C is variable. With this configuration, even if the third syringe 220 has a long piston handle (when the rear end of the piston handle extends far backward when the third syringe 220 is in a filled state), it can be held in the third syringe holder 320.

[0057] With this configuration, when third syringe holder 320 is in the forward position extended forward, even if third syringe 220 has a long-handled piston attached, third syringe 220 can be attached to third syringe holder 320. Furthermore, as shown in Figures 9 and 10, when third syringe holder 320 is in the syringe replacement position, third syringe 220 with a long-handled piston attached can be moved from above downward (-Z direction) and attached to third syringe holder 320.

[0058] Third syringe holder 320 is configured to be able to extend forward, but can also be used for injection by attaching a third syringe equipped with a short-handled piston when third syringe holder 320 is in the vicinity of the main body of chemical liquid injector 30. Furthermore, third syringe holder 320 may be configured to be able to be attached and used for injection when third syringe holder 320 is fixed at any position within the range in which support rod 322 can extend from chemical liquid injector 30.

[0059] In this embodiment, the third syringe holder 320 has been described as having a configuration that allows it to extend forward, but the present invention is not limited to this. The first or second syringe holder may also have a configuration that allows it to extend forward. Furthermore, two or three of the three syringe holders may have a configuration that allows them to extend forward, similar to the third syringe holder 320.

[0060] In this embodiment, third syringe holder 320 has been described as being configured to hold third syringe 220 having a circular cross section perpendicular to the axial direction, but the present invention is not limited to this. Third syringe holder 320 may be configured to hold a syringe having an elliptical cross section perpendicular to the axial direction, similar to first and second syringe holders 302A and 302B. Alternatively, third syringe holder 320 may be configured to accommodate three syringes with circular cross sections.

[0061] In the embodiment, the three syringes are described as being arranged in a triangular positional relationship with the base at the top when viewed from the axial direction, with two syringes attached at the top and one syringe attached at the bottom, in a normal operating state. However, the present invention is not limited to this arrangement. For example, the three syringes may be arranged in a triangular positional relationship with the base at the bottom when viewed from the axial direction, with one syringe attached at the top and two syringes attached at the bottom. In this case, the two lower syringe holders may be configured to be rotatable away from each other in a butterfly shape, as in the liquid injector 30 of Examples 1 and 2. This allows the two lower syringe holders to rotate away from each other, allowing syringes to be attached to and detached from the two lower syringe holders without interfering with the upper syringe holder. Even with a configuration of three syringe holders arranged in a triangular positional relationship with the base at the bottom when viewed from the axial direction, the effect of the present invention, that is, a compact liquid injector capable of accommodating three syringes, can be achieved, as in Examples 1 and 2.

[0062] As described above, the liquid injector 30 of this embodiment can accommodate three syringes while suppressing the horizontal expansion of the device, thereby providing a compact liquid injector.

[0063] Although the present invention has been described using the above-mentioned embodiments, the present invention is not limited to the configurations of the above-mentioned embodiments. Modifications of the components of the present invention and configurations equivalent to the components of the present invention are also included within the scope of the invention described in the claims. Furthermore, the above-mentioned embodiments can be combined as appropriate within the scope that does not substantially change the content of the present invention.

[0064] This application claims priority from Japanese Patent Application No. 2023-133265, filed on August 18, 2023, the entire contents of which are incorporated herein by reference.

[0065] 30 Chemical liquid injector 301A First plunger device (plunger) 301B Second plunger device (plunger) 301C Third plunger device (plunger) 302A First syringe holder (syringe holder) 302B Second syringe holder (syringe holder) 302C Third syringe holder (syringe holder) 304A First motor (motor) 304B Second motor (motor) 304C Third motor (motor)

Claims

1. A drug injection device for injecting drug solutions, comprising: three syringe holders to which syringes are attached and which are arranged in a triangular positional relationship in a cross section perpendicular to the axial direction of the syringes; three plungers for pressing the pistons of the attached syringes in the axial direction of the syringes relative to the three syringe holders; and three motors for driving the three plungers.

2. The liquid injection device according to claim 1, characterized in that the three syringe holders include a syringe holder configured to be rotatable about an axis located off the axis of the syringe mounted within the cross section.

3. The drug liquid injection device described in claim 2, characterized in that the three syringe holders include first and second syringe holders which are rotatable syringe holders, and the first and second syringe holders are rotatable in directions in which the axes of the syringes attached to each holder move away from each other.

4. The drug liquid injection device described in claim 3, characterized in that the first syringe holder is rotatable around a first rotation axis parallel to the axis of the corresponding plunger, and the second syringe holder is rotatable around a second rotation axis parallel to the axis of the corresponding plunger, and the first rotation axis and the second rotation axis are located on both sides of the two axes in a direction connecting the two axes of the plungers corresponding to the first and second syringe holders, respectively.

5. The drug liquid injection device as described in claim 4, characterized in that the three syringe holders include a third syringe holder to which a syringe can be attached and detached through the gap between the first and second syringe holders when the axes of the syringes attached to the first and second syringe holders, respectively, are rotated away from each other.

6. A liquid injection device as described in any one of claims 1 to 5, characterized in that the three syringe holders are arranged at the apexes of a triangle having a base on the vertically downward side when the liquid injection device is in its normal operating state.

7. A liquid injection device as described in any one of claims 1 to 5, characterized in that the three syringe holders are configured to be arranged at the apexes of a triangle having a base on the vertically upward side when the liquid injection device is in normal use.

8. A liquid injection device as described in any one of claims 1 to 5, characterized in that the three syringe holders include a syringe holder configured to be able to accommodate a syringe whose cross-section perpendicular to the axial direction is elliptical.

9. A liquid injection device as described in any one of claims 1 to 5, characterized in that the three syringe holders include a syringe holder configured to be able to accommodate a syringe whose cross-section perpendicular to the axial direction is circular.

10. A liquid injection device as claimed in any one of claims 1 to 5, characterized in that the three syringe holders include a syringe holder whose axial position relative to the corresponding plunger is changeable.

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