Syringe pumps, medical devices, and syringe pump self-test methods

Abstract

To provide a syringe pump which does not require a user to manually move a slider during self-testing.SOLUTION: A syringe pump includes: a slider which moves a plunger rod of a syringe in a delivery direction in which it is pushed into a barrel; a drive part which drives the slider in a feed direction and an opposite direction; a detector which detects a position of the slider; and a control unit which controls the position of the slider by driving the drive part. The slider moves between a first position and a second position nearer a first direction side than the first position. The control unit acquires information showing the position of the slider from the detector when the syringe pump is in a starting state. The control unit performs self-testing by moving the slider in a first direction at least for a prescribed distance after the slider is moved in a second direction so that the position of the slider is away from the second position for a prescribed distance or more when the position of the slider is not away from the second position for the prescribed distance or more.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present disclosure relates to a syringe pump, a medical device, and a method for self-testing a syringe pump. [Background technology]

[0002] Conventionally, syringe pumps have been known that pump a liquid drug from a syringe by moving a plunger rod of the syringe in a direction (feed direction) that pushes the plunger rod into the barrel of the syringe with a slider. For example, the syringe pump disclosed in Japanese Patent Laid-Open Publication No. 2004-24884 automatically performs a self-test (also called a "self-check," "self-diagnosis," or "operation check") when the power switch is pressed to turn on the power. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-24884 Summary of the Invention [Problem to be solved by the invention]

[0004] When performing a self-test, the syringe pump moves the slider a predetermined distance in the feeding direction without a syringe set in it. Depending on the slider position when the syringe pump is started, the slider may not be able to move the predetermined distance in the feeding direction. In this case, the medical professional (user) must manually move the slider in the opposite direction to the feeding direction.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a syringe pump that does not require the user to manually move a slider during self-testing, a medical device that includes such a syringe pump, and a method for self-testing a syringe pump. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a syringe pump includes a slider that moves a plunger rod of a syringe attached to the syringe pump in a first direction to push the plunger rod into the barrel of the syringe; a drive unit that drives the slider in the first direction and a second direction opposite to the first direction; a detector that detects the position of the slider; and a control unit that controls the position of the slider by driving the drive unit. The slider is movable between a first position and a second position that is closer to the first position in the first direction. When the syringe pump is activated, the control unit acquires information indicating the position of the slider from the detector. If the position of the slider is not at least a predetermined distance from the second position, the control unit moves the slider in the second direction so that the position of the slider is at least the predetermined distance from the second position. After moving the slider in the second direction, the control unit performs a self-test by moving the slider in the first direction at least a predetermined distance.

[0007] According to another aspect of the present disclosure, a medical device includes the above-described syringe pump. According to yet another aspect of the present disclosure, a syringe pump has a slider that moves in a first direction to push a plunger rod of a syringe into a barrel, the slider being movable between a first position and a second position that is closer to the first position in the first direction. A self-test method for a syringe pump includes the steps of: detecting a position of the slider when the syringe pump is activated; if the detected position of the slider is not at least a predetermined distance from the second position, moving the slider in a second direction opposite to the first direction so that the slider position is at least the predetermined distance from the second position; and performing a self-test by moving the slider in the second direction and then again the predetermined distance in the first direction. [Effects of the Invention]

[0008] According to the above disclosure, it is not necessary for the user to manually move the slider during the self-test. [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. 2 is a perspective view showing the appearance of a syringe pump and a syringe attached to the syringe pump. [Figure 3] FIG. 3 is a view taken along the line III in FIG. 2. [Figure 4] FIG. 4 is a view taken along line IV in FIG. 2. [Figure 5] FIG. 2 is a diagram showing an outline of the internal structure of a syringe pump. [Figure 6] 10 is a diagram showing a state in which the pressing surface of the slider is farthest from the flange holding portion. FIG. [Figure 7] 10 is a diagram showing a state in which the pressing surface of the slider is closest to the flange holding portion. FIG. [Figure 8] FIG. 2 is a diagram illustrating a hardware configuration of a syringe pump. [Figure 9] The slider is shown in position P1. [Figure 10] The slider is shown in position P2. [Figure 11] FIG. 4 is a flowchart illustrating a flow of processing executed in the syringe pump. [Figure 12] FIG. 10 is a diagram showing an example of a screen displaying the results of a self-test. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0011] [A. Appearance of medical device] Fig. 1 is a diagram showing a blood purification apparatus, as an example of medical equipment, in use. As shown in Fig. 1, the blood purification apparatus 1 includes a syringe pump 100. The blood purification apparatus is also called a dialysis apparatus.

[0012] [B. Appearance of the syringe pump] Fig. 2 is a perspective view showing the appearance of a syringe pump and a syringe attached to the syringe pump, Fig. 3 is a view taken along line III in Fig. 2, and Fig. 4 is a view taken along line IV in Fig. 2.

[0013] 2, a syringe 10 is attached to the syringe pump 100. The syringe 10 includes a barrel 20 and a plunger rod 30.

[0014] The barrel 20 has 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. The inside of the barrel 20 is filled with a medicinal liquid.

[0015] The plunger rod 30 is fitted inside the barrel 20 and has a second flange 31 at its rear end. A gasket portion 32 that comes into sliding contact with the inner peripheral surface of the barrel 20 is provided at the front end side of the plunger rod 30.

[0016] Syringe pump 100 is configured to start when displacement of elements (clamp 112 and slider 120, described below) that hold syringe 10 is detected in order to attach or detach syringe 10. This allows a medical professional (hereinafter also referred to as "user") to start syringe pump 100 by displacing the above elements in an attempt to attach a syringe when syringe pump 100 is not activated. Note that activation upon detection of displacement is not essential. The configuration of syringe pump 100 will be described in detail below.

[0017] As shown in FIGS. 2 to 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. In one implementation example, display 181 displays information about the drug filled in syringe 10, and display 182 displays information about the delivery (flow rate, etc.) of the drug filled in syringe 10. 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 panels.

[0018] Syringe pump 100 includes a barrel receiver 110 , a boot 117 , and a slider 120 .

[0019] The barrel 20 is placed on the barrel receiving part 110. The barrel receiving part 110 has a concave part that comes into contact with 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.

[0020] 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).

[0021] The slider 120 is movable relative to the barrel receiving portion 110. The distance between the barrel receiving portion 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 syringe 10 into the barrel 20 of the syringe 10 (negative direction of the X-axis) is referred to as the "feed direction." Furthermore, the direction opposite to the feed direction (positive direction of the X-axis) is also referred to as the "reverse direction."

[0022] 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.

[0023] Movable claw 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 is moved toward barrel 20 by slider 120, the medicinal liquid in barrel 20 is injected into the tube from inlet 22. Arrow D3 in FIG. 2 indicates the direction in which slider 120 moves away from barrel receiving portion 110 (i.e., the opposite direction) among the directions indicated by double-headed arrow D1.

[0024] Syringe pump 100 further includes a pressure sensor 140. Pressure sensor 140 detects whether or not pressure is being applied to pressure surface 122 by a member such as second fringe 31.

[0025] 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.

[0026] 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.

[0027] Syringe pump 100 includes clamp 112 above barrel receiving portion 110. Clamp 112 rotates in the direction of double arrow R0 and is extendable and retractable in the vertical direction (the direction of double arrow D2, the Z-axis direction). Clamp 112 includes extendable portion 112A and blade portion 112X.

[0028] [C. Internal structure of the syringe pump] 5 is a diagram showing an outline of the internal structure of syringe pump 100. As shown in FIG. 5, syringe pump 100 includes slider 120, drive unit 190, potentiometer 170, boot 117, and boot locking unit 118.

[0029] As described above, the slider 120 has the slider cover 121, the pressing surface 122, the movable claw portion 123, and the clutch lever 124. The slider 120 further has a pipe shaft 125, a nut holder 126, and an inner clutch shaft 128. A half nut 127 is attached to the nut holder 126. The inner clutch shaft 128 extends in the X-axis direction within the hollow of the pipe shaft 125.

[0030] When the user operates the clutch lever 124 , the inner clutch shaft 128 rotates in the pipe shaft 125 in a direction that corresponds to the operating direction of the clutch lever 124 .

[0031] 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 191 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 into a locked state in which manual movement of the slider 120 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 191 are disengaged based on the rotation of the inner clutch shaft 128. This puts the slider 120 into an unlocked state in which it can be moved manually.

[0032] The driving unit 190 includes a lead screw 191, gears 192 and 193, and a motor 194. The driving unit 190 is fixed in position within the syringe pump 100.

[0033] Lead screw 191 is rotatably supported by a bearing (not shown). Gear 192 is attached to the end of lead screw 191 so that its rotation axis is the same as that of lead screw 191. Gear 193 is attached to the output shaft of motor 194. Gear 193 meshes with gear 192.

[0034] Motor 194 is rotated by control unit 150 (FIG. 8), which will be described later. When motor 194 rotates forward (clockwise when viewed from the output shaft side), in this example, slider 120 moves in the negative direction of the X axis (toward motor 194) provided that the clutch is engaged. In other words, when motor 194 rotates forward, slider 120 moves in the feed direction to push plunger rod 30 of syringe 10 into barrel 20 of syringe 10.

[0035] When the motor 194 rotates in the reverse direction (counterclockwise as viewed from the output shaft side), in this example, the slider 120 moves in the positive direction of the X axis (away from the motor 194). In other words, when the motor 194 rotates in the reverse direction, the slider 120 moves in the reverse direction opposite to the feed direction, provided that the clutch is engaged.

[0036] In this example, the potentiometer 170 is a linear sliding and contact type meter. The potentiometer 170 includes a housing 171 and a shaft 172. The shaft 172 moves in 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 170 sends an output corresponding to the position of the shaft 172 to the control unit 150 (FIG. 8).

[0037] Boot 117 covers the periphery of pipe shaft 125 so that pipe shaft 125 is not exposed to the outside of syringe pump 100. 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 100 and does not move.

[0038] For ease of explanation, the following description will be given using the position of slider 120 (specifically, the position in the X-axis direction) as a reference for the position of pressing surface 122 of slider 120 (specifically, the position in the X-axis direction). However, the reference for the position of slider 120 is not limited to this.

[0039] 6 is a diagram showing a state in which the pressing surface 122 of the slider 120 is farthest from the flange holding portion 115. That is, FIG. 6 is a diagram showing a state in which the slider 120 is farthest from the motor 194.

[0040] For ease of explanation, as shown in Figure 6, the position of flange holding portion 115 in the X-axis direction is denoted as Po, and the position of pressing surface 122 in the X-axis direction is denoted as Pf. In the state shown in Figure 6, the length of the exposed portion of shaft 172 of potentiometer 170 is at its maximum. In the following, the distance between housing 171 of potentiometer 170 and nut holder 126 of slider 120 when pressing surface 122 is at its farthest from flange holding portion 115 as shown in Figure 6 will be referred to as "Lmax."

[0041] Fig. 7 is a diagram showing a state in which the pressing surface 122 of the slider 120 is closest to the flange holding portion 115. That is, Fig. 7 is a diagram showing a state in which the slider 120 is closest to the motor 194. More specifically, Fig. 7 is a diagram showing a state in which the pressing surface 122 is in contact with the flange holding portion 115, that is, a state in which the slider 120 is at the final position.

[0042] As shown in FIG. 7, the position of the pressing surface 122 in the X-axis direction is Po. That is, the position of the flange holding portion 115 and the position of the pressing surface 122 are the same. In the state of FIG. 7, the length of the exposed portion of the shaft 172 of the potentiometer 170 is minimum. Hereinafter, the distance between the housing 171 of the potentiometer 170 and the nut holder 126 of the slider 120 when the pressing surface 122 is closest to the flange holding portion 115 as shown in FIG. 7 will be referred to as "Lmin." Therefore, the distance (constant value) between the position Po and the position Pf is "Lmax-Lmin."

[0043] As described above, syringe pump 100 includes slider 120 that moves plunger rod 30 of syringe 10 attached to syringe pump 100 in a feed direction (first direction) that pushes the plunger rod 30 of syringe 10 into barrel 30 of syringe 10, drive unit 190 that drives slider 120 in the feed direction and in a direction opposite to the feed direction (second direction), potentiometer 170 (detector) that detects the position of slider 120, and control unit 150 (control unit) that controls the position of slider 120 by driving drive unit 190. Slider 120 is movable between position Pf (first position) and position Po (second position) that is closer to position Pf in the feed direction.

[0044] [D. Syringe Pump Hardware Configuration] Fig. 8 is a diagram showing the hardware configuration of syringe pump 100. As shown in Fig. 8, syringe pump 100 includes a control unit 150 that controls the operation of syringe pump 100. Control unit 150 includes a processor 151 that executes a given program, and memory 152 that stores the program executed by processor 151 and various data required for executing the program.

[0045] In syringe pump 100, the operations described in this embodiment are realized by processor 151 executing a given program. Note that syringe pump 100 may include a dedicated circuit such as an application specific integrated circuit (ASIC) or a field-programmable gate array (FPGA) instead of or in addition to processor 151.

[0046] Syringe pump 100 includes interface 101 for communicating with an external device. The communication may be wired, in which case interface 101 may be a USB (Universal Serial Bus) interface. The communication may be wireless, in which case interface 101 may be a network card. The communication method is not particularly limited.

[0047] Syringe pump 100 includes potentiometers 114 and 170. Potentiometer 114 outputs a voltage value corresponding to the position of clamp 112 (blade portion 112X) in the direction of double arrow D2. Potentiometer 170 outputs a voltage value corresponding to the position of slider 120 in the direction of double arrow D1. 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.

[0048] Processor 151 of control unit 150 identifies the position of slider 120 in the direction of double arrow D1 (X-axis direction) based on the voltage value from potentiometer 170. Specifically, processor 151 identifies the position of slider 120 as a position between positions Po and Pf, as described with reference to FIGS.

[0049] When plunger rod 30 is set on slider 120, the position of plunger rod 30 changes according to the position of slider 120. Memory 152 may store the remaining amount of drug in the syringe according to the combination of syringe size and voltage value (position of plunger rod 30), and processor 151 may output the remaining amount of drug according to the voltage value from potentiometer 170.

[0050] Processor 151 determines the position of clamp 112 in the direction of double-headed arrow D2 based on the voltage value from potentiometer 114. Memory 152 may store voltage values ​​corresponding to syringe sizes, and processor 151 may output the syringe size (e.g., 10 mL syringe, 20 mL syringe, etc.) corresponding to the voltage value from potentiometer 170. In one implementation example, after setting barrel 20 of syringe 10 in barrel receiving portion 110, the user lowers clamp 112 (more specifically, blade portion 112X) to a position where it abuts against barrel 20. As a result, the position of clamp 112 (more specifically, blade portion 112X) in the direction of double-headed arrow D2 changes depending on the diameter of barrel 20, and thereby changes depending on the size of barrel 20.

[0051] Syringe pump 100 includes a force sensor (not shown). The force sensor detects the magnitude of the force applied to slider 120 in the direction of arrow D3 in FIG. 2 and outputs the detected force to control unit 150. Hall elements 131 also output the detected force to control unit 150.

[0052] Syringe pump 100 includes motor 194. Motor 194 is typically a stepping motor. Control unit 150 drives motor 194 to move slider 120 in the direction of double arrow D1 (X-axis direction).

[0053] Syringe pump 100 includes rotary encoder 195. Rotary encoder 195 detects the amount of rotation of motor 194 and outputs it to control unit 150.

[0054] Operation panel 180 is connected to control unit 150. Signals corresponding to operations on various switches in operation panel 180, including start switch 183, are input to processor 151. Processor 151 controls the display of displays 181 and 182.

[0055] Each of the displacement detection sensors 160, 911, 912, and 921 is connected to the control unit 150. The processor 151 acquires the detection output from each of the displacement detection sensors 160, 911, 912, and 921.

[0056] [E. Syringe Pump Self-Test] The syringe pump 100 is capable of performing a self-test. Specifically, in the syringe pump 100, the processor 151 performs a self-test (self-check, self-diagnosis, operation check) of the syringe pump 100.

[0057] Syringe pump 100 may check any item in the self-test, but in one implementation example, checks are made on the following items (e1) to (e8) in the self-test.

[0058] (e1) Barrel detection sensor check The processor 151 checks the operation of the sensor (Hall element 131) for detecting whether the barrel 20 is placed on the barrel receiving portion 110 as a "barrel detection sensor check."

[0059] When the barrel 20 is not set in the barrel receiving portion 110, the magnetic flux of the magnet 132 reaches the Hall element 131. On the other hand, when the barrel 20 is set in the barrel receiving portion 110, the presser plate 119 is urged toward the right side of FIG. 3 (the side where the slider 120 is located) by the first flange 21 of the barrel 20, and this makes the distance between the Hall element 131 and the magnet 132 longer than when the barrel 20 is not set in the barrel receiving portion 110. As a result, the magnetic flux of the magnet 132 does not reach the Hall element 131.

[0060] In the "barrel detection sensor check," if the Hall element 131 detects the magnetic flux of the magnet 132, the processor 151 determines that the operation of the Hall element 131 is normal, and if the Hall element 131 does not detect the magnetic flux, it determines that the operation is abnormal. As a result, if the Hall element 131 is in a state where it cannot detect magnetic flux, or if the barrel 20 is set in the barrel receiver 110 when the "barrel detection sensor check" is executed, the operation of the Hall element 131 is determined to be abnormal.

[0061] (e2) Check the clutch detection sensor The processor 151 checks the operation of the sensor (displacement detection sensor 160) for detecting the state (locked / unlocked) of the clutch lever 124 as a "clutch detection sensor check."

[0062] In the "clutch detection sensor check," processor 151 confirms that receiver 162 detects the light emitted from transmitter 161, and that receiver 162 does not detect light when transmitter 161 is not emitting light.

[0063] More specifically, the processor 151 determines that the operation of the displacement detection sensor 160 is normal if the detection output of the light receiver 162 when the light projector 161 is instructed to emit light indicates that light from the light projector 161 has been detected, and if the detection output of the light receiver 162 when the light projector 161 is instructed not to emit light indicates that light from the light projector 161 has not been detected.

[0064] On the other hand, if the detection output of the light receiver 162 when the light projector 161 is instructed to emit light indicates that it has not detected light from the light projector 161, or if the detection output of the light receiver 162 when the light projector 161 is instructed not to emit light indicates that it has detected light from the light projector 161, the processor 151 determines that the operation of the displacement detection sensor 160 is abnormal.

[0065] (e3) Check the plunger detection sensor The processor 151 checks the operation of the sensor (pressure sensor 140) for detecting the pressure applied by an element such as the second flange 31 as the "pressure detecting sensor check."

[0066] In one implementation, pressure sensor 140 is configured to be capable of outputting a voltage value in the range of 0.0 V to 5.0 V, outputting a voltage value of 1.0 V when not being pressed, and outputting a voltage value of 4.0 V when being pressed. During the self-test, processor 151 determines that pressure sensor 140 is operating normally if the voltage value output from pressure sensor 140 is within the range of 1.0 V to 4.0 V, and determines that pressure sensor 140 is operating abnormally if the voltage value is outside this range.

[0067] (e4) Syringe size detection sensor check Processor 151 checks the operation of the sensor (potentiometer 114) for detecting the size of the syringe placed on barrel receiver 110 as a "syringe size detection sensor check."

[0068] In one implementation, potentiometer 114 is configured to be capable of outputting a voltage value in the range of 0.0V to 5.0V, and to output a voltage value of 1.0V to 4.0V depending on the size of barrel 20. During the self-test, processor 151 determines that potentiometer 114 is operating normally if the voltage value output from potentiometer 114 is within the range of 1.0V to 4.0V, and determines that potentiometer 114 is operating abnormally if the voltage value is outside this range.

[0069] (e5) Check the slider position detection sensor As a "slider position detection sensor check", the processor 151 checks the operation of the sensor (potentiometer 170) for detecting the position of the slider 120 in the direction of the double-headed arrow D1.

[0070] In one implementation example, potentiometer 170 is configured to be capable of outputting a voltage value in the range of 0.0 V to 5.0 V, and to output a voltage value of 1.0 V to 4.0 V depending on the position of slider 120. During the self-test, processor 151 determines that potentiometer 170 is operating normally if the voltage value output from potentiometer 170 is within the range of 1.0 V to 4.0 V, and determines that potentiometer 170 is operating abnormally if the voltage value is outside this range.

[0071] (e6) Sensor check for blockage detection The processor 151 checks the operation of a sensor (force sensor) for detecting the presence or absence of an obstruction in the flow path of the medicine filled in the syringe 10 as the "obstruction detection sensor check."

[0072] In one implementation, the force sensor is configured to output a voltage value in the range of 0.0 V to 5.0 V, output a voltage value of 1.0 V when no blockage occurs in the flow path, and output a voltage value from a given value above 1.0 V to 4.0 V depending on the degree of blockage when a blockage occurs in the flow path. During the self-test, processor 151 determines that the force sensor is operating normally if the voltage value output from the force sensor is within the range of 1.0 V to 4.0 V, and determines that the force sensor is operating abnormally if the voltage value is outside of this range.

[0073] (e7) Motor drive check Processor 151 checks the operation of motor 194 as a "motor drive check." More specifically, in the self-test, processor 151 applies a given drive force to motor 194 for a certain period of time and determines the amount of rotation of motor 194 during that certain period of time based on the detection output of rotary encoder 195.

[0074] Memory 152 stores a reference value for the amount of rotation of motor 194. Processor 151 determines that the operation of motor 194 is normal if the difference between the identified amount of rotation and the reference value in memory 152 is less than a certain value, and determines that the operation of motor 194 is abnormal if the difference is equal to or greater than the certain value.

[0075] (e8) Syringe unattached state detection The processor 151 performs a self-test to check the state of the syringe 10 in the syringe pump 100 as "syringe unattached state detection."

[0076] In one implementation example, in the self-test, processor 151 determines that syringe 10 is attached if Hall element 131 does not detect the magnetic flux of magnet 132 and the voltage value output by pressure sensor 140 is 4.0 V (a voltage value corresponding to a pressed state). On the other hand, if Hall element 131 detects the magnetic flux of magnet 132 and the voltage value output by pressure sensor 140 is a value lower than 4.0 V (a voltage value corresponding to a non-pressed state), processor 151 determines that syringe 10 is not attached.

[0077] The self-test is usually performed without the syringe 10 attached. Therefore, if the syringe 10 is attached to the syringe pump 100, and the processor 151 determines that the syringe 10 was attached when the self-test started, it outputs a message (warning) to that effect.

[0078] [F. Slider Movement Control During Self-Test] In the slider position detection sensor check, the motor 194 must be driven to move the slider 120 in the feed direction by a predetermined distance Lth or more. For example, the slider must be moved by at least 5.0 mm when the slider position detection sensor check is performed. A motor drive check is usually performed simultaneously with the slider position detection sensor check.

[0079] Fig. 9 shows a state in which the slider 120 is at position P1. More specifically, Fig. 9 shows a state in which the pressing surface 122 is at position P1. Note that position P1 is further toward position Pf than position P3, which is the above-mentioned predetermined distance Lth away from position Po.

[0080] The length of the exposed portion of the shaft 172 at this time (i.e., the distance between the housing 171 and the nut holder 126) is defined as "L1." In this case, the distance Ld between the pressing surface 122 and the flange holding portion 115 (in this case, the distance between the position Po and the position P1) is "L1-Lmin."

[0081] The distance between position Po and position P1 is longer than the distance between position Po and position P3 (i.e., the predetermined distance Lth). Therefore, when slider 120 is in the position shown in Fig. 9, the slider position detection sensor can be checked by moving slider 120 from this position in the feed direction (the direction of arrow 501) by the predetermined distance Lth.

[0082] Fig. 10 shows a state in which the slider 120 is at position P2. More specifically, Fig. 10 shows a state in which the pressing surface 122 is at position P2. Note that position P2 is closer to position Po than position P3, which is the above-mentioned predetermined distance Lth away from position Po.

[0083] The length of the exposed portion of the shaft 172 at this time (i.e., the distance between the housing 171 and the nut holder 126) is "L2." The distance Ld between the pressing surface 122 and the flange holding portion 115 (in this case, the distance between the position Po and the position P2) is "L2-Lmin."

[0084] The distance between positions Po and P2 is shorter than the distance between positions Po and P3 (i.e., the predetermined distance Lth). Therefore, when slider 120 is in the position shown in FIG. 10, slider 120 cannot be moved the predetermined distance Lth in the feed direction (the direction of arrow 502) from this position. Therefore, in this state, the slider position detection sensor check cannot be performed. Therefore, the control unit 150 executes the following process.

[0085] (1) When syringe pump 100 is activated, control unit 71 acquires information indicating the position of slider 120 from potentiometer 170. If the position of slider 120 is a predetermined distance Lth or more away from position Po, as shown in FIG. 9 , control unit 150 performs a self-test by moving slider 120 the predetermined distance Lth in the feed direction.

[0086] 10, if the position of slider 120 is not at least the predetermined distance Lth from position Po, control unit 150 moves slider 120 in the reverse direction so that the position of slider 120 is at least the predetermined distance Lth from position Po. After moving slider 120 in the reverse direction (after the movement is completed), control unit 150 performs a self-test by moving slider 120 in the feed direction by at least the predetermined distance Lth.

[0087] With this configuration, the user does not need to manually move the slider 120 during a self-test that includes at least a slider position detection sensor check and a motor drive check. This reduces the user's effort. Specifically, at startup, the control unit 150 controls the slider 120 to move in the reverse direction as necessary, so that the distance required for the self-test can be secured without the user having to manually operate the position of the slider 120.

[0088] (2) Preferably, when the position of the slider 120 is not at least the predetermined distance Lth from the position Po, the control unit 150 moves the slider 120 in the reverse direction so that the position of the slider 120 is the predetermined distance Lth from the position Po. With this configuration, the moving distance of the slider 120 in the reverse direction can be minimized.

[0089] (3) More specifically, the control unit 150 compares the position of the slider 120 (in this example, the position of the pressing surface 122) with a position P3 that is a predetermined distance Lth away from the position Po in the reverse direction, based on information indicating the position of the slider 120 acquired from the potentiometer 170. The control unit 150 moves the slider 120 in the reverse direction to the position P3, on the condition that the position of the slider 120 is on the feed direction side of the position P3.

[0090] (4) More specifically, when the position of slider 120 is further in the feed direction than position P3, control unit 150 calculates the distance between the position of slider 120 and position P3. Control unit 150 moves slider 120 in the reverse direction by the calculated distance.

[0091] The syringe pump 100 outputs a predetermined warning if the clutch is not engaged when the syringe pump 100 is activated. The syringe pump 100 also outputs a predetermined warning if a syringe 10 is attached to the syringe pump 100. This configuration allows the user to notice any defects.

[0092] 11 is a flowchart for explaining the flow of processing executed in syringe pump 100. In syringe pump 100, processor 151 may execute a given program to realize the processing shown in FIG.

[0093] 11 is initiated when syringe pump 100 is connected to a commercial power source and is in a sleep state, which means that power is applied to control unit 150, sensors for detecting the displacement of clamp 112 (displacement detection sensors 911 and 912), and a sensor for detecting the displacement of slider 120 (displacement detection sensor 921), but at least one other element is not.

[0094] As will be described later, when displacement of at least one of clamp 112 and slider 120 is detected, syringe pump 100 is activated and enters an activated state. In the activated state, power is also applied to elements that were not powered on in the sleep state. As described above, activation in response to detection of displacement is not essential.

[0095] In step S10, syringe pump 100 determines whether start switch 183 has been operated or whether displacement has been detected of at least one of clamp 112 and slider 120. Syringe pump 100 determines whether clamp 112 has been displaced based on the detection outputs from displacement detection sensor 911 and displacement detection sensor 912, and determines whether slider 120 has been displaced based on the detection output from displacement detection sensor 921.

[0096] Syringe pump 100 repeats the control of step S10 at regular intervals (NO in step S10) until it determines that start switch 183 has been operated or that displacement of at least one of clamp 112 and slider 120 has been detected. If syringe pump 100 determines that start switch 183 has been operated or that displacement of at least one of clamp 112 and slider 120 has been detected (YES in step S10), it proceeds to control step S12.

[0097] In step S12, the syringe pump 100 starts up the syringe pump 100. As a result, the syringe pump 100 transitions from the sleep state to the active state.

[0098] In step S14, the syringe pump 100 detects the position of the slider 120. In step S16, the syringe pump 100 determines, based on the detection result of the position of the slider 120, whether the distance Ld between the slider 120 and the nut holder 126 is equal to or greater than the distance Lth serving as a threshold value.

[0099] If it is determined that distance Ld is equal to or greater than distance Lth (YES in step S16), syringe pump 100 starts a self-test by moving slider 120 in the feed direction in step S18. If it is determined that distance Ld is less than distance Lth (NO in step S16), syringe pump 100 moves slider 120 in the reverse direction in step S20. Syringe pump 100 then returns the process to step S16.

[0100] After step S18, in step S22, syringe pump 100 determines whether the self-test has ended, and if it has ended (YES in step S22), the control proceeds to step S24.

[0101] In step S24, the syringe pump 100 displays the results of the self-test on the display 182.

[0102] In step S26, syringe pump 100 performs an operation according to the instruction. The instruction to syringe pump 100 may be input from operation panel 180 or from an external device.

[0103] In step S28, the syringe pump 100 determines whether the start switch 183 has been operated, and if it determines that it has been operated (YES in step S28), the control proceeds to step S32; if not (NO in step S28), the control proceeds to step S30.

[0104] In step S30, the syringe pump 100 determines whether a state has occurred in which no operation has been performed on the syringe pump 100 for a certain period of time or longer. If the syringe pump 100 determines that this state has not occurred (NO in step S30), it returns control to step S26, and if it determines that this state has occurred (YES in step S30), it proceeds to step S32.

[0105] In one implementation example, the "operation" in step S30 includes an operation on operation panel 180 and movement of clamp 112 or slider 120. That is, if the user does not operate operation panel 180, move clamp 112, or move slider 120 for a certain period of time or longer, control proceeds from step S30 to step S32.

[0106] In step S32, the syringe pump 100 transitions the state of the syringe pump 100 from the active state to the sleep state, thereby deactivating the syringe pump 100. Thereafter, the syringe pump 100 returns control to step S10.

[0107] [G. Self-test result output] 12 is a diagram showing an example of a screen for displaying the results of the self-test. A screen 1200 includes a column 1210 for displaying the results of each item of the self-test, and a button 1222.

[0108] Syringe pump 100 displays the results of the above-described items (1) to (8) of the self-test in column 1210. More specifically, for items (1) to (7), syringe pump 100 displays the result "OK" if the check result is "normal," and displays the result "NG" if the check result is "abnormal." For item (8), syringe pump 100 displays "OK" if it determines that syringe 10 was not attached when the self-test started, and determines "NG" if it determines that syringe 10 was attached. In the example of FIG. 12, "OK" is displayed as the result for all items (1) to (8).

[0109] It should be noted that button 1222 is a button for instructing re-execution of the self-test. The user can instruct syringe pump 100 to re-execute the self-test by operating button 1222. When the user is instructed to re-execute the self-test, the self-test starts again.

[0110] <Modification> In the above, a linear sliding and contact type meter is used as the potentiometer 170, but the present invention is not limited to this. Any device (sensor, encoder, etc.) that can measure the position of the slider 120 can be used.

[0111] 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]

[0112] 1 blood purification device, 10 syringe, 20 barrel, 21 first flange, 22 liquid port 30 plunger rod, 31 second flange, 32 gasket portion, 71 control unit, 100 syringe pump, 101 interface, 110 barrel receiving portion, 111 groove portion, 112 clamp, 112A telescopic portion, 112X blade portion, 114, 170 potentiometer, 115 flange holding portion, 117 boot, 118 boot engaging portion, 119 holding plate, 120 slider, 121 slider cover, 122 pressing surface, 123 movable claw portion, 124 clutch lever, 125 pipe shaft, 126 nut holder, 127 half nut, 128 inner clutch shaft, 131 hall element, 132 magnet, 140 pressing sensor, 150 control unit, 151 processor, 152 memory, 160, 911, 912, 921 Displacement detection sensor, 161, light emitter, 162, light receiver, 171, housing, 172, shaft, 180, operation panel, 181, 182, display, 183, start switch, 190, drive unit, 191, lead screw, 192, 193, gears, 194, motor, 195, rotary encoder, 1200, screen, 1222, button.

Claims

1. 1. A syringe pump comprising: a slider that moves a plunger rod of a syringe attached to the syringe pump in a first direction to push the plunger rod into a barrel of the syringe; a driving unit that drives the slider in the first direction 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 position of the slider by driving the drive unit, the slider is movable between a first position and a second position located closer to the first direction than the first position; The control unit When the syringe pump is activated, information indicating the position of the slider is obtained from the detector; If the position of the slider is not at least a predetermined distance from the second position, moving the slider in the second direction so that the position of the slider is at least the predetermined distance from the second position; The syringe pump performs a self-test by moving the slider in the second direction and then moving the slider in the first direction at least the predetermined distance.

2. 2. The syringe pump according to claim 1, wherein, when the position of the slider is not separated from the second position by at least the predetermined distance, the control unit moves the slider in the second direction so that the position of the slider is separated from the second position by the predetermined distance.

3. The control unit based on the information indicating the position of the slider obtained from the detector, comparing the position of the slider with a third position that is spaced apart from the second position by the predetermined distance in the second direction; 3. The syringe pump according to claim 2, wherein the slider is moved in the second direction to the third position on the condition that the slider is positioned on the first direction side of the third position.

4. The control unit When the position of the slider is closer to the third position in the first direction, a distance between the position of the slider and the third position is calculated; The syringe pump of claim 3 , wherein the slider is moved in the second direction by the calculated distance.

5. A medical device comprising the syringe pump according to any one of claims 1 to 4.

6. 1. A method for self-testing a syringe pump, comprising: the syringe pump has a slider that moves a plunger rod of the syringe in a first direction to push the plunger rod into the barrel, the slider being movable between a first position and a second position that is closer to the first direction than the first position; The self-test method for the syringe pump includes: detecting a position of the slider when the syringe pump is activated; If the detected position of the slider is not at least a predetermined distance from the second position, moving the slider in a second direction opposite to the first direction so that the position of the slider is at least the predetermined distance from the second position; and performing the self-test by moving the slider in the second direction and then moving the slider the predetermined distance in the first direction.

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