Syringe pump and method for determining assembly failure

Abstract

To provide a technique capable of detecting an assembly failure of a pre-filled syringe to be attached to a syringe pump.SOLUTION: A syringe pump comprises: a potentiometer 170 that detects a position of a slider 120; an arithmetic unit 151 that controls movement of the slider 120; and a memory 152 that stores a reference position of a pre-filled syringe 10 when the pre-filled syringe 10 is properly attached. The arithmetic unit 151 determines an assembly failure of a barrel 20 and a plunger rod 30 based on a position of the slider 120 detected by the potentiometer 170 when the pre-filled syringe 10 is attached, and the reference position stored in the memory 152.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a syringe pump and a method for determining assembly defects using a syringe pump. [Background technology]

[0002] Pre-filled syringes assembled with a barrel and a plunger rod are known. For example, Registered Utility Model No. 3191047 (Patent Document 1) discloses a pre-filled syringe that is filled with a medicinal solution in advance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Registered Utility Model No. 3191047 Summary of the Invention [Problem to be solved by the invention]

[0004] The prefilled syringe disclosed in Registered Utility Model No. 3191047 (Patent Document 1) can be disassembled into an outer cylinder main body portion corresponding to the barrel and a plunger corresponding to the plunger rod. This makes the prefilled syringe easy to transport, but it can be assembled when used. However, when assembling the prefilled syringe, improper assembly can cause problems such as the plunger coming off the barrel.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a technology that can detect assembly defects in a pre-filled syringe attached to a syringe pump. [Means for solving the problem]

[0006] The present disclosure relates to a syringe pump to which a prefilled syringe assembled by a barrel and a plunger rod is attached. The syringe pump includes a slider that moves the plunger rod in a first direction in which the plunger rod is pushed into the barrel with the prefilled syringe attached, and in a second direction opposite to the first direction, a detector that detects the position of the slider, a control unit that controls the movement of the slider, and a memory unit that stores the reference position of the prefilled syringe when the prefilled syringe is properly attached. The control unit determines whether the barrel and the plunger rod are assembled properly based on the position of the slider detected by the detector when the prefilled syringe is attached and the reference position stored in the memory unit.

[0007] The present disclosure relates to a method for determining an assembly defect of a prefilled syringe assembled by a barrel and a plunger rod using a syringe pump. The syringe pump has a slider that moves the plunger rod in a first direction in which the plunger rod is pushed into the barrel with the prefilled syringe attached, and in a second direction opposite to the first direction. The process executed by a computer includes: detecting the position of the slider when the prefilled syringe is attached; and determining an assembly defect based on the position of the slider and a reference position when the prefilled syringe is properly attached. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to determine assembly defects between the barrel and the plunger rod based on the position of the slider when the prefilled syringe is attached and the reference position when the prefilled syringe is attached properly. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a blood purification device as an example of a medical device in use. [Figure 2]FIG. 1 is a diagram illustrating a pre-filled syringe according to the first embodiment. [Figure 3] FIG. 1 is a front view of a syringe pump according to a first embodiment. [Figure 4] FIG. 2 is a rear view of the syringe pump according to the first embodiment. [Figure 5] FIG. 2 is a rear view of the syringe pump according to the first embodiment with the cover removed. [Figure 6] 1 is a rear view of the syringe pump according to the first embodiment with a pre-filled syringe attached. FIG. [Figure 7] 1 is a diagram illustrating a hardware configuration of a syringe pump according to a first embodiment. [Figure 8] 4 is a flowchart showing a process executed in the syringe pump according to the first embodiment. [Figure 9] FIG. 10 is a rear view of the syringe pump according to the second embodiment with the cover removed. DETAILED DESCRIPTION OF THE INVENTION

[0010] <First Embodiment> Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, identical components are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Furthermore, in the embodiments described below, when numbers, quantities, etc. are mentioned, the scope of the present invention is not necessarily limited to those numbers, quantities, etc., unless otherwise specified.

[0011] Fig. 1 is a diagram showing a state in which a blood purification device 1, as an example of a medical device, is in use. As shown in Fig. 1, the blood purification device 1 includes a syringe pump 100. A medicinal solution is delivered from the syringe pump 100 to a patient 2 through a tube. The blood purification device 1 is also called a dialysis device.

[0012] Fig. 2 is a diagram for explaining the prefilled syringe 10 according to the first embodiment. The prefilled syringe 10 includes a barrel 20 and a plunger rod 30. The prefilled syringe 10 is used by assembling the barrel 20 and the plunger rod 30. Fig. 2(A) is a diagram showing the prefilled syringe 10 when the barrel 20 and the plunger rod 30 are properly assembled. Fig. 2(B) is a diagram showing the prefilled syringe 10 when the barrel 20 and the plunger rod 30 are improperly assembled.

[0013] The barrel 20 is a container having a substantially cylindrical outer shape. A liquid inlet 22 is provided at the tip of the barrel 20. A first flange 21 is provided at the rear end of the barrel 20. The barrel 20 is made of a transparent or translucent resin such as polypropylene. In the pre-filled syringe 10, the inside of the barrel 20 is pre-filled with a medicinal liquid.

[0014] The plunger rod 30 is fitted inside the barrel 20 and has a second flange 31 at its rear end. The second flange 31 is fixed by a movable claw 123 provided on a slider 120 for moving the plunger rod 30 toward the barrel 20. A gasket 32 ​​that comes into sliding contact with the inner circumferential surface of the barrel 20 is provided on the tip side of the plunger rod 30.

[0015] The gasket portion 32 has a female thread portion formed by a space extending inward from the rear end portion. The female thread portion has a female thread shape. A protrusion 34 is provided at the tip portion of the plunger rod 30 on the first flange 21 side. The protrusion 34 has a male thread shape. The female thread portion provided on the gasket portion 32 and the male thread portion provided on the protrusion 34 of the plunger rod 30 can be threaded together. As the female thread portion and the male thread portion are threaded together normally, the plunger rod 30 will not be separated from the gasket portion 32.

[0016] 2(A), in the case of a faulty assembly, the plunger rod 30 is longer by a distance C1 in the direction opposite to the pushing direction of the barrel 20, as shown in FIG. 2(B). This is because the female thread portion and the male thread portion were not properly threaded together and were assembled in a loosely engaged state, which increased the overall length of the prefilled syringe 10.

[0017] If such an assembly error occurs, gasket portion 32 will become detached from plunger rod 30. If there is a difference in elevation between patient 2 and syringe pump 100, there is a possibility that a siphoning phenomenon will occur, in which only detached gasket portion 32 moves toward the tip of barrel 20 due to the differential pressure, causing the medicinal solution to be rapidly injected into patient 2. Therefore, as will be described below, syringe pump 100 according to embodiment 1 is configured to be able to detect assembly errors in the attached prefilled syringe 10.

[0018] Fig. 3 is a plan view of syringe pump 100 according to embodiment 1. Fig. 4 is a rear view of syringe pump 100 according to embodiment 1. Syringe pump 100 is fitted with pre-filled syringe 10 described above.

[0019] The syringe pump 100 is configured to start when displacement of elements (a clamp 112 and a slider 120, which will be described later) that hold the prefilled syringe 10 is detected. This allows a medical professional (hereinafter also referred to as a "user") to start the syringe pump 100 by displacing the above elements in an attempt to attach the prefilled syringe 10 when the syringe pump 100 is not activated. Note that activation upon detection of displacement is not essential. The configuration of the syringe pump 100 will be described in detail below.

[0020] As shown in FIGS. 3 and 4, syringe pump 100 includes operation panel 180. Operation panel 180 is provided with various switches including start switch 183, and displays 181 and 182. For example, display 181 displays information about the medicinal liquid filled in prefilled syringe 10, and display 182 displays information about the delivery of the medicinal liquid filled in prefilled syringe 10 (such as flow rate). However, the information displayed on displays 181 and 182 is not limited to this. Displays 181 and 182 may be provided with touch panels, in which case a user can input information to syringe pump 100 by touching the touch panel.

[0021] Syringe pump 100 includes a barrel receiver 110 , a boot 117 , and a slider 120 .

[0022] The barrel 20 of the prefilled syringe 10 is placed on the barrel receiving part 110. The barrel receiving part 110 contacts the lower part of the outer circumferential surface of the barrel 20. A flange holding part 115 that holds the first flange 21 is provided at the rear end of the barrel receiving part 110. The flange holding part 115 has a groove part 111 and a presser plate 119.

[0023] A presser plate 119 is inserted into the groove 111. A member (not shown) that biases the presser plate 119 toward the left in FIG. 3 (the negative direction of the X-axis) is disposed in the groove 111. A Hall element 131 is provided in the main body of the barrel receiving part 110, and a magnet 132 is embedded in the presser plate 119. The first flange 21 is inserted between the Hall element 131 and the magnet 132 (presser plate 119).

[0024] The slider 120 is movable relative to the barrel receiving part 110. The distance between the barrel receiving part 110 and the slider 120 is changed by the movement of the slider 120. Note that, hereinafter, the direction in which the slider 120 pushes the plunger rod 30 of the prefilled syringe 10 into the barrel 20 of the prefilled syringe 10 (negative direction of the X-axis) is referred to as the "feed direction (first direction)."

[0025] The slider 120 is configured by combining multiple parts. Such a slider 120 is also called a "slider assembly." Specifically, the slider 120 has a slider cover 121, a pressing surface 122 that presses the second flange 31, and a movable claw portion 123 that sandwiches and holds the second flange 31 between the slider cover 121 and the pressing surface 122.

[0026] Movable claw portion 123 is biased in a direction approaching pressing surface 122 by a biasing mechanism such as a spring. Slider 120 holds plunger rod 30 so that it can move toward barrel 20. Note that double-headed arrow D1 indicates the movement direction of slider 120. When plunger rod 30 moves toward barrel 20 by slider 120, the medicinal liquid in barrel 20 is injected into the tube from injection port 22. Arrow D3 in FIG. 3 indicates the direction indicated by double-headed arrow D1 in which slider 120 moves away from barrel receiving portion 110 (i.e., the opposite direction (second direction)).

[0027] Syringe pump 100 further includes pressure sensor 140. Pressure sensor 140 is an example of a pressure sensor that measures pressure. Pressure sensor 140 detects whether or not pressure is being applied to pressure surface 122 by a member such as second flange 31.

[0028] The slider 120 further has a clutch lever 124 for manually adjusting the position of the slider 120 itself and the position of the movable claw 123 in the extension direction of the plunger rod 30 when attaching or detaching the plunger rod 30. Specifically, by rotating the clutch lever 124 in one direction, the slider 120 enters a locked state in which manual movement of the slider 120 is restricted, and the movable claw 123 is maintained in a state in which it is biased toward the pressing surface 122. By rotating the clutch lever 124 in the other direction, the slider 120 enters an unlocked state, and the movable claw 123 is moved away from the pressing surface 122 against the biasing force.

[0029] The configuration of the slider 120 is not limited to the above, and the slider 120 may have a pressing surface 122 that presses the second flange 31, and a fixing claw portion that houses the second flange 31 between the pressing surface 122.

[0030] Syringe pump 100 includes clamp 112 above barrel receiving portion 110. Clamp 112 rotates in the direction of double arrow D0 and is extendable and retractable in the vertical direction (the direction of double arrow D2, Z-axis direction). Clamp 112 includes extendable portion 112A and blade portion 112X.

[0031] Syringe pump 100 is entirely covered by cover 103. At the end of cover 103 facing the negative direction of the X axis, a holder 113 is arranged to hold a tube extending from inlet 22 when prefilled syringe 10 is attached.

[0032] Next, a state in which cover 103 of syringe pump 100 is removed will be described. Fig. 5 is a rear view of syringe pump 100 according to embodiment 1 in a state in which cover 103 is removed. Fig. 6 is a rear view of syringe pump 100 according to embodiment 1 in a state in which pre-filled syringe 10 is attached.

[0033] Syringe pump 100 includes guide member 201 and potentiometer 170. Guide member 201 is provided with guide groove 202. Guide groove 202 is a groove for guiding potentiometer 170 in the diagonal direction of double-headed arrow E1 (third direction).

[0034] When moving along guide groove 202, potentiometer 170 moves in the direction of double arrow E2 (X-axis direction) and also in the direction of double arrow E3 (Z-axis direction). If there is an assembly error when prefilled syringe 10 is attached to syringe pump 100, slider 120 will be longer than normal by a distance C1, as shown in FIG. 2. Potentiometer 170 outputs a voltage value that corresponds to the position in the direction of double arrow E3, which changes in response to distance C1.

[0035] In this way, potentiometer 170 detects the position of slider 120 from the detection position in the direction perpendicular to the actual movement direction (E3 direction) rather than the actual movement direction (E2 direction) of slider 120. This makes it possible to detect a range shorter than the actual movement distance, allowing the entire syringe pump 100 to be made smaller.

[0036] Next, a description will be given of the hardware configuration of syringe pump 100. Fig. 7 is a diagram showing the hardware configuration of syringe pump 100 according to embodiment 1. As shown in Fig. 7, syringe pump 100 includes control unit 150, interface 101, potentiometers 114 and 170, reading unit 191, force sensor 142, Hall element 131, motor 194, rotary encoder 195, notification unit 190, operation panel 180, displacement detection sensors 160, 911, 912, and 921, and pressure sensor 140.

[0037] The control unit 150 controls the operation of the syringe pump 100. The control unit 150 includes a calculation device (control unit) 151, a memory 152, and a storage device (storage unit) 153.

[0038] The arithmetic device 151 is a computing entity (computer) that executes predetermined processing. The arithmetic device 151 is configured with a processor such as a central processing unit (CPU), a micro-processing unit (MPU), a tensor processing unit (TPU), or a graphics processing unit (GPU). A processor, which is an example of the arithmetic device 151, has the function of executing predetermined processing by executing a predetermined program. However, some or all of these functions may be implemented using dedicated hardware circuits such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). The term "processor" is not limited to a processor in the narrow sense that executes processing using a stored program, such as a CPU, MPU, TPU, or GPU, but may also include hardwired circuits such as an ASIC or FPGA. The arithmetic device 151 described above can also be interpreted as a processing circuitry that executes predetermined processing. The arithmetic device 151 may be configured on one chip or multiple chips. Furthermore, the processor and associated processing circuitry may be comprised of multiple computers interconnected by wire or wirelessly, such as via a local area network or a wireless network. The processor and associated processing circuitry may also be comprised of a cloud computer that performs remote calculations based on input data and outputs the results of the calculations to other devices at remote locations.

[0039] The memory 152 includes a volatile storage area (for example, a working area) that temporarily stores program code, work memory, etc. when the arithmetic unit 151 executes various programs. Examples of the memory 152 include volatile memories such as DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory), and non-volatile memories such as ROM (Read Only Memory) and flash memory.

[0040] The storage device 153 stores various programs and various data executed by the arithmetic device 151. The storage device 153 may be one or more non-transitory computer readable media, or may be one or more computer readable storage media. Examples of the storage device 153 include a hard disk drive (HDD) and a solid state drive (SSD).

[0041] The interface 101 communicates between the syringe pump 100 and an external device. The communication may be wired, in which case the interface 101 may be a USB (Universal Serial Bus) interface. The communication may be wireless, in which case the interface 101 may be a network card. The communication method is not particularly limited.

[0042] The potentiometer 114 outputs a voltage value corresponding to the position of the clamp 112 (wing portion 112X) in the direction of the double-headed arrow D2. The potentiometer 170 (detector) outputs a voltage value corresponding to the position of the slider 120.

[0043] Specifically, potentiometer 170 outputs a voltage value that corresponds to the position in the direction of double arrow E3, which changes with movement in the direction of double arrow E1. Both potentiometers 114 and 170 output voltage values ​​to control unit 150. Here, a method for using the detection outputs of potentiometers 114 and 170 will be described.

[0044] The arithmetic device 151 of the control unit 150 determines the position of the slider 120 in the direction of the double-headed arrow D1 (X-axis direction) based on the voltage value from the potentiometer 170.

[0045] When the plunger rod 30 is set on the slider 120, the position of the slider 120 changes according to the position of the plunger rod 30. The memory device 153 stores the reference position and voltage value when the prefilled syringe 10 is properly assembled. The arithmetic device 151 determines whether or not the assembly is defective based on a value corresponding to the voltage value from the potentiometer 170 and the value stored in the memory device 153.

[0046] The arithmetic device 151 determines the position of the clamp 112 in the direction of the double-headed arrow D2 based on the voltage value from the potentiometer 114. The memory 152 may store a voltage value corresponding to the size of the syringe, and the arithmetic device 151 may output the syringe size (e.g., a 10 mL syringe, a 20 mL syringe, etc.) corresponding to the voltage value from the potentiometer 170. For example, after the user sets the barrel 20 of the prefilled syringe 10 in the barrel receiving portion 110, the user lowers the clamp 112 (more specifically, the blade portion 112X) to a position where it abuts against the barrel 20. As a result, the position of the clamp 112 (more specifically, the blade portion 112X) in the direction of the double-headed arrow D2 changes according to the diameter of the barrel 20, and thus changes according to the size of the barrel 20.

[0047] The reading unit 191 is configured with a device such as a camera that can read information such as one-dimensional codes and two-dimensional codes. Here, a label corresponding to an identifier such as drug information, information on whether the syringe is a normal syringe or a prefilled syringe, and information on the syringe size is attached to the prefilled syringe 10 in advance. The computing device 151 determines whether the syringe is a prefilled syringe 10 or not based on the information acquired by the reading unit 191.

[0048] The force sensor 142 detects the magnitude of the force applied to the slider 120 in the direction of the arrow D3 and outputs the detected magnitude to the control unit 150. The hall element 131 detects whether or not the barrel 20 is placed on the barrel receiving portion 110. The hall element 131 also outputs the detection results to the control unit 150.

[0049] The motor 194 is typically a stepping motor. The control unit 150 drives the motor 194 to move the slider 120 in the direction of the double-headed arrow D1 (the X-axis direction).

[0050] The rotary encoder 195 detects the amount of rotation of the motor 194 and outputs it to the control unit 150 .

[0051] The notification unit 190 executes a predetermined notification (for example, notification by sound or light emission) in response to a command from the control unit 150. The notification from the notification unit 190 may be notification other than sound or light emission, or may be a combination of two or more of these.

[0052] The operation panel 180 is connected to the control unit 150. Signals corresponding to the operation of various switches in the operation panel 180, including a start switch 183, are input to the arithmetic device 151. The arithmetic device 151 controls the display of the displays 181 and 182.

[0053] Each of the displacement detection sensors 160, 911, 912, and 921 is connected to the control unit 150. The arithmetic device 151 acquires detection outputs from each of the displacement detection sensors 160, 911, 912, and 921. The displacement detection sensor 160 is a sensor for detecting the state (locked / unlocked) of the clutch lever 124. The displacement detection sensors 911 and 912 are sensors for detecting the displacement of the clamp 112. The displacement detection sensor 921 is a sensor for detecting the displacement of the slider 120.

[0054] Pressure sensor 140 is a sensor that measures the pressure applied to barrel 20 when the liquid medicine is delivered from barrel 20, which is a container. The pressure applied to barrel 20 is detected on pressing surface 122 as a pressure applied by the member of second flange 31.

[0055] Next, the processing executed by the arithmetic device 151 will be specifically described. Fig. 8 is a flowchart showing the processing executed in the syringe pump 100 according to the first embodiment. The processing of the flowchart in Fig. 8 is repeatedly called as a subroutine from a main routine under the control of the arithmetic device 151 and executed. The arithmetic device 151 executes the determination of assembly defects of the pre-filled syringe 10 in the following processing.

[0056] First, in step S (hereinafter simply referred to as "S") 1, the arithmetic device 151 determines whether the target syringe is a normal syringe or a pre-filled syringe 10 based on information about an identifier such as a label attached to the syringe detected by the reading unit 191. When the arithmetic device 151 determines that the target syringe is not a pre-filled syringe 10 (NO in S1), the processing returns from the subroutine to the main routine.

[0057] When the arithmetic device 151 determines that the target syringe is a prefilled syringe 10 (YES in S1), it determines whether or not a prefilled syringe 10 is attached to the syringe pump 100 (S2). The arithmetic device 151 determines whether or not a prefilled syringe 10 is attached to the syringe pump 100 from the detection outputs of, for example, the potentiometers 114, 170, the Hall element 131, etc. When the arithmetic device 151 determines that a prefilled syringe 10 is not attached to the syringe pump 100 (NO in S2), it returns the process from the subroutine to the main routine.

[0058] When the arithmetic device 151 determines that the prefilled syringe 10 is attached to the syringe pump 100 (YES in S2), it detects the position of the slider 120 from the detection value of the potentiometer 170 (S3). Next, the arithmetic device 151 determines whether or not the prefilled syringe 10 has been assembled correctly (S4). Specifically, the arithmetic device 151 determines whether or not the prefilled syringe 10 has been assembled correctly by comparing the position of the slider 120 detected by the potentiometer 170 with a reference position of the slider 120 when the prefilled syringe 10 has been assembled correctly, which is stored in advance in the memory 152.

[0059] If the arithmetic device 151 determines that the prefilled syringe 10 is assembled correctly (no assembly defects have occurred) (YES in S4), it starts the liquid delivery by moving the slider 120 in the negative direction of the X-axis and pushing the plunger rod 30 into the barrel 20 (S5), and returns the process from the subroutine to the main routine.

[0060] If the arithmetic device 151 determines that the pre-filled syringe 10 is not assembled properly (that an assembly error has occurred) (NO in S4), it controls the notification unit 190 to output an alarm of assembly error (S6), and returns the processing from the subroutine to the main routine.

[0061] The syringe pump 100 determines whether the pre-filled syringe 10 is properly assembled by comparing the position of the slider 120 detected by the potentiometer 170 with a reference position of the slider 120 when the pre-filled syringe 10 is properly assembled, which is stored in advance in the memory 152. This makes it easy to determine whether the barrel 20 and the plunger rod 30 are improperly assembled.

[0062] <Embodiment 2> A syringe pump 100A according to embodiment 2 will now be described. Fig. 9 is a rear view of the syringe pump according to embodiment 2 with the cover removed. In Fig. 9, some of the components of syringe pump 100A according to embodiment 2 differ in shape from those of syringe pump 100 according to embodiment 1, but components with the same reference numerals have the same functions, and therefore detailed description thereof will be omitted.

[0063] 9, syringe pump 100A includes slider 120, drive unit 290, potentiometer 170A, boot 117, and boot locking unit 118. Slider 120 includes slider cover 121, movable claw 123, and clutch lever 124. Slider 120 also includes pipe shaft 125, nut holder 126, and inner clutch shaft 128. Half nut 127 is attached to nut holder 126. Inner clutch shaft 128 extends in the X-axis direction within the hollow of pipe shaft 125.

[0064] When the user operates the clutch lever 124, the inner clutch shaft 128 rotates within the pipe shaft 125 in a direction corresponding to the operating direction of the clutch lever 124. When the user rotates the clutch lever 124 in one direction, the groove of the half nut 127 and the groove of the lead screw 291 engage with each other (hereinafter also referred to as "engagement of the clutch") based on the rotation of the inner clutch shaft 128. This puts the slider 120 in a locked state in which manual movement is restricted. On the other hand, when the user rotates the clutch lever 124 in the other direction, the groove of the half nut 127 and the groove of the lead screw 291 are disengaged based on the rotation of the inner clutch shaft 128. This puts the slider 120 in an unlocked state in which it can be moved manually.

[0065] Drive unit 290 includes lead screw 291, gears 292 and 293, and motor 294. Drive unit 290 is fixed in position within syringe pump 100A. Lead screw 291 is rotatably supported by a bearing (not shown). Gear 292 is attached to the end of lead screw 291 so that its rotation axis is the same as that of lead screw 291. Gear 293 is attached to the output shaft of motor 294. Gear 293 meshes with gear 292.

[0066] Motor 294 rotates in response to a signal from control unit 150. When motor 294 rotates forward (clockwise as viewed from the output shaft side), slider 120 moves in the negative direction of the X axis (toward motor 294) provided that the clutch is engaged. In other words, when motor 294 rotates forward, slider 120 moves in the feed direction to push plunger rod 30 of syringe 10 into barrel 20 of syringe 10.

[0067] When the motor 294 rotates in the reverse direction (counterclockwise as viewed from the output shaft side), the slider 120 moves in the positive direction of the X axis (away from the motor 294). In other words, when the motor 294 rotates in the reverse direction, the slider 120 moves in the reverse direction opposite to the feed direction, provided that the clutch is engaged.

[0068] The potentiometer 170A is a linear sliding and contact type meter. The potentiometer 170A includes a housing 171 and a shaft 172. The shaft 172 moves in the direction of the double arrow E2 (the X-axis direction). The base end of the shaft 172 is movably attached within the housing 171. The tip end of the shaft 172 is attached to the nut holder 126. The potentiometer 170A sends an output corresponding to the position of the shaft 172 to the control unit 150.

[0069] If there is an assembly error when prefilled syringe 10 is attached to syringe pump 100A, slider 120 will be longer than normal by the distance of the assembly error. Potentiometer 170A outputs a voltage value corresponding to the position in the direction of double-headed arrow E2, which changes in accordance with the distance of the assembly error. In this way, syringe pump 100A can detect an assembly error only from operation in the direction of double-headed arrow E2, which is the same direction as the movement of slider 120.

[0070] Boot 117 covers the periphery of pipe shaft 125 so that pipe shaft 125 is not exposed to the outside of syringe pump 100A. Boot 117 has a bellows structure and is expandable. One end of boot 117 is attached to slider 120. The other end of the boot is attached to boot locking portion 118. Boot locking portion 118 is fixed in position within syringe pump 100A and does not move.

[0071] <Aspect> (1) The present disclosure relates to a syringe pump to which a prefilled syringe assembled with a barrel and a plunger rod is attached. The syringe pump includes: a slider that moves the plunger rod in a first direction in which the plunger rod is pushed into the barrel with the prefilled syringe attached, and in a second direction opposite to the first direction; a detector that detects the position of the slider; a control unit that controls the movement of the slider; and a memory unit that stores the reference position of the prefilled syringe when the prefilled syringe is properly attached. The control unit determines whether the barrel and plunger rod are improperly assembled based on the position of the slider detected by the detector when the prefilled syringe is attached and the reference position stored in the memory unit.

[0072] According to the syringe pump of the present disclosure, it is possible to determine whether the barrel and plunger rod are assembled properly based on the position of the slider detected by the detector when the prefilled syringe is attached and the reference position stored in the memory unit.

[0073] (2) In the syringe pump according to (1), when the control unit determines that no assembly defect has occurred, the control unit moves the slider in the first direction.

[0074] According to the syringe pump of the present disclosure, when it is determined that no assembly defects have occurred, the slider is moved in the first direction to start the liquid transfer.

[0075] (3) The syringe pump according to (1) or (2), further comprising a notification unit that notifies the occurrence of an assembly defect. When the control unit determines that an assembly defect has occurred, the notification unit notifies the occurrence of the assembly defect.

[0076] According to the syringe pump of the present disclosure, when it is determined that an assembly defect has occurred, the notification unit notifies the user of the assembly defect, so that the occurrence of the assembly defect can be easily confirmed.

[0077] (4) The syringe pump according to any one of (1) to (3), further comprising a reading unit that reads an identifier of the attached syringe. The control unit determines whether the attached syringe is a pre-filled syringe based on the identifier read by the reading unit.

[0078] According to the syringe pump of the present disclosure, it is possible to easily determine whether or not the attached syringe is a pre-filled syringe based on the identifier read by the reading unit.

[0079] (5) A syringe pump according to any one of (1) to (4), wherein the detector moves in a third direction inclined at a predetermined angle with respect to the first direction, and detects the position of the slider from the detection position of the detector in the third direction.

[0080] According to the syringe pump of the present disclosure, the position of the slider can be detected from a detection position in a direction different from the movement direction of the slider, thereby reducing the movement of the detector in the movement direction of the slider and reducing the overall size of the syringe pump.

[0081] (6) In the syringe pump according to any one of (1) to (4), the detector moves in a first direction, and detects the position of the slider from the detection position of the detector in the first direction.

[0082] According to the syringe pump of the present disclosure, the position of the slider can be detected from a detection position in the same direction as the movement direction of the slider, so the size of the syringe pump can be reduced in the direction perpendicular to the movement direction of the slider (direction E3).

[0083] (7) The present disclosure relates to a method for determining an assembly defect of a prefilled syringe assembled by a barrel and a plunger rod using a syringe pump. The syringe pump includes a slider that moves the plunger rod in a first direction in which the plunger rod is pushed into the barrel with the prefilled syringe attached, and in a second direction opposite to the first direction. The process executed by a computer includes a step of detecting the position of the slider when the prefilled syringe is attached, and a step of determining an assembly defect based on the position of the slider and a reference position when the prefilled syringe is properly attached.

[0084] According to the determination method of the present disclosure, it is possible to determine whether an assembly is defective based on the position of the slider when the prefilled syringe is attached and the reference position when the prefilled syringe is properly attached.

[0085] <Modification> In the above embodiment, the reading unit 191 reads a label such as a one-dimensional code or two-dimensional code corresponding to the identifier to determine whether or not the syringe is a pre-filled syringe 10. The user may visually determine whether or not the syringe is a pre-filled syringe 10 and input the information into the syringe pump 100.

[0086] An IC tag may be attached to the pre-filled syringe 10. In this case, the reading unit 191 may be an RFID (Radio Frequency Identification) that can read the IC tag.

[0087] The reading unit 191 may be a device having an OCR (Optical Character Recognition / Reader). The reading unit 191 may be used to recognize the information on the label as character information.

[0088] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the scope of the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0089] 1 Blood purification device, 2 Patient, 10 Prefilled syringe, 20 Barrel, 21 First flange, 22 Inlet, 30 Plunger rod, 31 Second flange, 32 Gasket portion, 34 Protrusion, 100 Syringe pump, 101 Interface, 103 Cover, 110 Barrel receiving portion, 111 Groove portion, 112 Clamp, 113 Holding portion, 114, 170 Potentiometer, 115 Flange holding portion, 117 Boot, 119 Pressing plate, 120 Slider, 121 Slider cover, 122 Pressing surface, 123 Movable claw portion, 124 Clutch lever, 131 Hall element, 132 Magnet, 140 Pressing force sensor, 142 Force sensor, 150 Control unit, 151 Calculating device, 152 Memory, 153 Memory device, 160,911,912,921 Displacement detection sensor, 180 Operation panel, 181,182 Display, 183 Start switch, 190 Notification unit, 191 Reading unit, 194 Motor, 195 Rotary encoder, 201 Guide member, 202 Guide groove.

Claims

1. A syringe pump to which a pre-filled syringe assembled by a barrel and a plunger rod is attached, A slider that moves the plunger rod in a first direction in which the plunger rod is pushed into the barrel with the prefilled syringe attached, and in a second direction opposite to the first direction; a detector for detecting the position of the slider; a control unit that controls the movement of the slider; a memory unit that stores a reference position of the prefilled syringe when the prefilled syringe is normally attached, The control unit determines an assembly defect between the barrel and the plunger rod based on the position of the slider detected by the detector when the prefilled syringe is attached and the reference position stored in the memory unit.

2. The syringe pump according to claim 1 , wherein the control unit moves the slider in the first direction when it is determined that no assembly defect has occurred.

3. a notification unit that notifies the occurrence of the assembly defect, The syringe pump according to claim 1 , wherein the control unit, when determining that the assembly defect has occurred, notifies the notification unit of the assembly defect.

4. Further provided is a reading unit that reads an identifier of the attached syringe; The syringe pump according to claim 1 , wherein the control unit determines whether the attached syringe is the pre-filled syringe based on the identifier read by the reading unit.

5. 4. The syringe pump according to claim 1, wherein the detector moves in a third direction inclined at a predetermined angle with respect to the first direction, and the position of the slider is detected from a detection position of the detector in the third direction.

6. The syringe pump according to claim 1 , wherein the detector moves in the first direction, and detects the position of the slider from a detection position of the detector in the first direction.

7. A method for determining whether a pre-filled syringe assembled by a barrel and a plunger rod is defective using a syringe pump, comprising: The syringe pump includes a slider that moves the plunger rod in a first direction in which the plunger rod is pushed into the barrel and in a second direction opposite to the first direction when the prefilled syringe is attached, The process performed by the computer is detecting the position of the slider when the pre-filled syringe is attached; and determining whether the pre-filled syringe is properly attached based on the position of the slider and a reference position when the pre-filled syringe is properly attached.

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