Syringe drive device

Abstract

To provide a syringe drive device that can be made compact.SOLUTION: A syringe drive device 2 includes a motor 41 and a control unit 63. The motor 41 drives a syringe 3. The control unit 63 drives the motor 41 based on a set value to control a flow rate indicating the amount of fluid discharged from the syringe 3 per unit time. The control unit 63 divides a unit time into a first period T1 and a second period T2 based on a first flow rate F(H) indicating a flow rate corresponding to a first set value, a second flow rate F(L) indicating a flow rate corresponding to a second set value, and a target flow rate F indicating a target value of the flow rate. The first flow rate F(H) indicates a flow rate larger than the target flow rate F. The second flow rate F(L) indicates a flow rate smaller than the target flow rate F. The control unit 63 controls the motor 41 based on the second set value in the first period T1, and controls the motor 41 based on the first set value in the second period T2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a syringe drive device. [Background technology]

[0002] A particulate detection device including a syringe drive device is known. In the particulate detection device, the syringe drive device drives a syringe to flow a fluid through a microchannel. For example, microorganisms or cells are dispersed in the fluid. Specifically, the syringe drive device includes a motor that moves the plunger of the syringe up and down (for example, see Patent Document 1).

[0003] A syringe drive device used in a particle detector is required to have a high quantitative accuracy as well as the ability to supply a minute amount of fluid to a minute flow channel. A syringe pump equipped with a stepping motor and a reducer is known as a syringe drive device with high quantitative accuracy (for example, see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-70223 A [Patent Document 2] Japanese Patent Application Publication No. 10-184534 Summary of the Invention [Problem to be solved by the invention]

[0005] However, a syringe drive device equipped with a reducer increases in size by the amount of the reducer.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a syringe drive device that can be made compact. [Means for solving the problem]

[0007] According to one aspect of the present invention, a syringe drive device drives a syringe to eject a fluid from the syringe. The syringe drive device includes a motor and a control unit. The motor drives the syringe. The control unit drives the motor based on a set value to control a flow rate indicating an amount of the fluid ejected from the syringe per unit time. The control unit divides the unit time into a first period and a second period based on a first flow rate indicating a flow rate corresponding to a first set value, a second flow rate indicating a flow rate corresponding to a second set value, and a target flow rate indicating a target value of the flow rate. The first flow rate indicates a flow rate greater than the target flow rate. The second flow rate indicates a flow rate smaller than the target flow rate. The control unit controls the motor in the first period based on the second set value, and controls the motor in the second period based on the first set value.

[0008] In one embodiment, the control unit divides the unit time into the first period and the second period based on a ratio between a first differential flow rate indicating a difference between the first flow rate and the target flow rate, and a second differential flow rate indicating a difference between the second flow rate and the target flow rate.

[0009] In one embodiment, the first set value indicates a set value corresponding to a flow rate that is greater than and closest to the target flow rate among the possible set values, and the second set value indicates a set value corresponding to a flow rate that is smaller than and closest to the target flow rate among the possible set values.

[0010] In one embodiment, the syringe includes a cylindrical body, a gasket, and a plunger. The cylindrical body contains the fluid and is connected to a microchannel through which the contained fluid flows. The gasket is slidable inside the cylindrical body. The plunger is connected to the gasket. The motor drives the plunger. Effect of the Invention

[0011] According to the syringe drive device of the present invention, the syringe drive device can be made compact. [Brief description of the drawings]

[0012] [Figure 1] 1A is a block diagram showing a configuration of a syringe drive device according to an embodiment of the present invention, and FIG. [Diagram 2] FIG. 13 is a diagram illustrating an example of a conversion table. [Diagram 3] 5 is a flowchart showing a process executed by a controller included in the syringe drive device according to the embodiment of the present invention. [Figure 4] 1A is a diagram showing the flow rate of a fluid discharged from a syringe, and FIG. 1B is another diagram showing the flow rate of a fluid discharged from a syringe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the syringe drive device of the present invention will be described with reference to the drawings (FIGS. 1(a) to 4(b)). However, the present invention is not limited to the following embodiment, and can be embodied in various forms without departing from the gist of the present invention. Note that where explanations are repeated, they may be omitted as appropriate. Also, in the drawings, the same or corresponding parts are given the same reference symbols, and explanations will not be repeated.

[0014] FIG. 1(a) is a block diagram showing the configuration of a syringe drive device 2 of this embodiment. FIG. 1(b) is a plan view showing an example of a substrate 5. As shown in FIG. 1(a), the syringe drive device 2 drives a syringe 3 to eject a fluid from the syringe 3. The syringe drive device 2 of this embodiment drives the syringe 3 to supply the fluid to the substrate 5. In this embodiment, the fluid includes a liquid. For example, the fluid may be a sample liquid. For example, microorganisms or cells to be analyzed are dispersed in the sample liquid.

[0015] As shown in Fig. 1(a), the syringe 3 extends in a certain direction. Hereinafter, the direction in which the syringe 3 extends may be referred to as the "longitudinal direction D1". In this embodiment, the syringe 3 is disposed such that its longitudinal direction D1 is approximately parallel to the up-down direction. Specifically, the syringe 3 is held by a holding member (not shown) in a position perpendicular to the horizontal plane.

[0016] The syringe 3 has a cylindrical body 31 and a plunger 32. The cylindrical body 31 contains a fluid. The cylindrical body 31 is a cylindrical member extending in a longitudinal direction D1 (in the present embodiment, the vertical direction). The plunger 32 is inserted into the cylindrical body 31. The syringe driving device 2 drives the plunger 32 to eject the fluid from the cylindrical body 31. In the present embodiment, the cylindrical body 31 is connected to a substrate 5, and the sample liquid ejected from the cylindrical body 31 is supplied to the substrate 5.

[0017] The cylindrical body 31 has a tip portion 311 and a main body portion 312. In this embodiment, the tip portion 311 constitutes the lower end portion of the cylindrical body 31. The main body portion 312 is, for example, cylindrical, and the diameter of the main body portion 312 is approximately constant in the longitudinal direction D1. The tip portion 311 is tubular with a smaller diameter than the main body portion 312, and is in communication with the main body portion 312.

[0018] The plunger 32 is movable in the longitudinal direction D1 (in the present embodiment, in the vertical direction). The plunger 32 is inserted into the cylindrical body 31 from the end opposite to the tip 311 of the cylindrical body 31. In the present embodiment, the plunger 32 is inserted into the cylindrical body 31 from the upper end opening of the cylindrical body 31. As the plunger 32 moves toward the tip 311 of the cylindrical body 31, the fluid contained inside the cylindrical body 31 is discharged from the tip 311 of the cylindrical body 31. In the present embodiment, as the plunger 32 inserted inside the cylindrical body 31 moves in the downward direction D2, the fluid is discharged from the tip 311 of the cylindrical body 31.

[0019] More specifically, the syringe 3 further includes a gasket 321. The gasket 321 is disposed inside the cylindrical body 31. The gasket 321 is slidable inside the cylindrical body 31. The plunger 32 is connected to the gasket 321. By disposing the gasket 321 inside the cylindrical body 31, the sealing performance of the syringe 3 is improved.

[0020] 1(b), the substrate 5 may have a slide 51 and a transparent cover 52. The slide 51 has a groove 511. The cover 52 covers the groove 511.

[0021] The slide 51 is, for example, rectangular in plan view. The slide 51 may be transparent. In this embodiment, the slide 51 is held in a position along a horizontal plane by a holding member (not shown). Therefore, the upper surface of the groove 511 is open.

[0022] The groove portion 511 extends in a certain direction. In this embodiment, the groove portion 511 extends in the horizontal direction. The volume of the groove portion 511 is, for example, 5 mL or more and 10 mL or less. The groove portion 511 is an example of a "microchannel." The tip portion 311 of the cylindrical body 31 shown in FIG. 1(a) is connected to the groove portion 511. The fluid contained in the cylindrical body 31 flows into the groove portion 511 (microchannel).

[0023] The cover 52 may cover the entire surface (top surface) of the preparation 51. The cover 52 has a liquid supply port 521 and a liquid discharge port 522. The liquid supply port 521 is a through-hole that penetrates the cover 52. In this embodiment, the liquid supply port 521 penetrates the cover 52 in the vertical direction. Similarly, the liquid discharge port 522 is a through-hole that penetrates the cover 52. In this embodiment, the liquid discharge port 522 penetrates the cover 52 in the vertical direction.

[0024] Liquid supply port 521 is provided at a position facing groove portion 511. For example, liquid supply port 521 is provided at a position facing one end portion of groove portion 511. A short tube (not shown) into which tip portion 311 of syringe 3 (cylindrical body 31) can be inserted is provided upright at liquid supply port 521. Sample liquid discharged from syringe 3 flows from liquid supply port 521 into groove portion 511 via the short tube.

[0025] Similarly, liquid discharge outlet 522 is provided at a position facing groove portion 511. For example, liquid discharge outlet 522 is provided at a position facing the other end of groove portion 511. One end of a waste liquid tube (not shown) is connected to liquid discharge outlet 522. The other end of the waste liquid tube may be connected to, for example, a collection tank.

[0026] As shown in FIG. 1(a), the syringe drive device 2 includes a syringe drive unit 4 and a control device 6. The syringe drive unit 4 drives the syringe 3. Specifically, the syringe drive unit 4 moves the plunger 32 in the longitudinal direction D1. In this embodiment, the syringe drive unit 4 raises and lowers the plunger 32. The control device 6 controls the syringe drive unit 4 so that a fixed amount of fluid is discharged from the syringe 3. The fixed amount may be set to an amount corresponding to the volume of the groove portion 511 shown in FIG. 1(b). The fixed amount is, for example, 5 mL or more and 10 mL or less.

[0027] More specifically, the control device 6 controls the syringe driving unit 4 so that the flow rate of the fluid discharged from the syringe 3 corresponds to a preset value. Hereinafter, the flow rate of the fluid indicates the amount of the fluid discharged from the syringe 3 per unit time. Hereinafter, the flow rate of the fluid discharged from the syringe 3 may be referred to as the "discharge flow rate."

[0028] The syringe drive unit 4 has a motor 41, a motor drive unit 42, and a drive force transmission mechanism 43. The motor 41 drives the syringe 3. Specifically, the motor 41 drives the plunger 32. More specifically, the motor drive unit 42 supplies a drive signal to the motor 41. The motor 41 drives based on the drive signal. As a result, a drive force is generated from the motor 41. The drive force transmission mechanism 43 transmits the drive force generated from the motor 41 to the plunger 32. As a result, the plunger 32 is driven.

[0029] The motor 41 can rotate in both forward and reverse directions. The number of rotations per unit time [rpm] of the motor 41 can be controlled. In other words, the rotation speed of the motor 41 can be controlled. The motor 41 includes, for example, a servo motor. The motor 41 may be, for example, a stepping motor.

[0030] The motor driving unit 42 generates a drive signal for driving the motor 41 based on a set value transmitted from the control device 6. The set value is, for example, a reference voltage. When the motor 41 operates based on the drive signal, the discharge flow rate becomes a flow rate corresponding to the set value. Here, the set value is an integer value. Hereinafter, the set value may be referred to as a "drive set value."

[0031] Specifically, the motor drive unit 42 has a motor drive circuit. The motor drive circuit generates a drive signal based on a drive setting value (reference voltage). The motor drive circuit may generate a pulse signal as the drive signal. The pulse signal may be a voltage signal. The motor drive circuit may include a plurality of switch elements. The switch elements are, for example, transistors.

[0032] The driving force transmission mechanism 43 transmits the driving force generated by the motor 41 to the plunger 32 so that the plunger 32 moves in the longitudinal direction D1. Specifically, the driving force transmission mechanism 43 converts the rotational motion of the motor 41 into the upward and downward motion of the plunger 32. The driving force transmission mechanism 43 may include, for example, a ball screw mechanism. Note that the motor 41 and the driving force transmission mechanism 43 are not provided with a reducer.

[0033] The control device 6 has an operation unit 61, a memory unit 62, and a control unit 63. The operation unit 61 is operated by an operator. The operation unit 61 accepts the setting of a target flow rate. The target flow rate indicates a target value for the flow rate of the fluid to be discharged from the syringe 3. The value of the target flow rate that can be set by the operator via the operation unit 61 is an integer value. Hereinafter, the setting value of the target flow rate may be referred to as the "set flow rate F".

[0034] The operation unit 61 further receives an instruction to start rotating (start driving) the motor 41. In other words, the operation unit 61 receives an instruction to start discharging the fluid from the syringe 3. In this embodiment, the operation unit 61 receives an instruction to start supplying the fluid to the substrate 5 (groove portion 511). The operator operates the operation unit 61 to set the set flow rate F, and then issues an instruction to start rotating the motor 41. As a result, the motor 41 is driven and the fluid is discharged from the syringe 3.

[0035] The operation unit 61 may have, for example, a display such as a liquid crystal display or an organic EL (electroluminescence) display, and a plurality of push buttons. Alternatively, the operation unit 61 may have a touch sensor superimposed on the display in addition to or instead of the push buttons. In this case, the touch sensor and the display may form a graphical user interface.

[0036] The storage unit 62 stores various information for controlling the syringe driving unit 4. For example, the storage unit 62 may store conversion information for determining a drive setting value based on a set flow rate F (target flow rate). The conversion information may include data indicating a conversion formula, or may include data indicating a conversion table 621 (see FIG. 2). The information stored in the storage unit 62 may include a computer program.

[0037] The storage unit 62 has a storage device. The storage device stores various information. The storage device includes, for example, a semiconductor storage device (semiconductor memory). The storage unit 62 may have at least one of a ROM (Read Only Memory) and a RAM (Random Access Memory) as a storage device. Alternatively, instead of the RAM and ROM, or in addition to the RAM and ROM, the storage unit 62 may have at least one of a flash memory, an EPROM (Erasable Programmable Read Only Memory), and an EEPROM (Electrically Erasable Programmable Read Only Memory). The storage unit 62 may also have a storage device as a storage device. For example, the storage unit 62 may have at least one of an HDD (Hard Disk Drive) and an SDD (Solid Disk Drive) as a storage device. The storage unit 62 may include a removable medium as a storage device. For example, the storage unit 62 may include a USB memory as a removable medium.

[0038] The control unit 63 drives the motor 41 based on the drive set value to control the amount of fluid (discharge flow rate) discharged from the syringe 3 (cylinder 31) per unit time. Specifically, the control unit 63 determines the drive set value based on the set flow rate F. More specifically, the control unit 63 determines the drive set value by referring to the conversion information. Then, the control unit 63 transmits the drive set value to the motor drive unit 42. As a result, the motor drive unit 42 drives the motor 41 based on the drive set value. The motor 41 drives based on the drive set value, so that the discharge flow rate becomes a flow rate corresponding to the drive set value.

[0039] The control unit 63 may have a processor such as a central processing unit (CPU) or a micro processing unit (MPU), or may have a logic circuit such as a logic integrated circuit (IC), an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA).

[0040] Next, the conversion table 621 stored in the storage unit 62 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the conversion table 621. The storage unit 62 may store the conversion table 621 as conversion information. In this case, the control unit 63 determines the drive setting value by referring to the conversion table 621.

[0041] 2, the conversion table 621 associates a set flow rate F, a set value (drive set value), and a discharge flow rate (flow rate of the fluid actually discharged from the syringe 3). Specifically, the conversion table 621 has a set flow rate column 22, a set value column 23, and a discharge flow rate column 24.

[0042] The set flow rate column 22 indicates a target flow rate that can be set in the syringe driving device 2 (control device 6). As shown in FIG. 2, the settable target flow rate values ​​are integer values. The set value column 23 indicates a drive setting value that can be set in the motor driving unit 42. As shown in FIG. 2, the settable drive setting value values ​​are integer values. The conversion table 621 associates one drive setting value with each set flow rate F. For example, the conversion table 621 associates a drive setting value of "4" with a set flow rate F of "5 μL / min."

[0043] In more detail, the conversion table 621 associates, with each set flow rate F, the drive setting value at which the discharge flow rate is closest to the set flow rate F. For example, when the drive setting value is 4, the discharge flow rate is 4.71 μL / min, and when the drive setting value is 5, the discharge flow rate is 5.88 μL / min. Therefore, since 4.71 μL / min is closer to the set flow rate F "5 μL / min" than 5.88 μL / min, the drive setting value "4" is associated with the set flow rate F "5 μL / min."

[0044] The discharge flow rate column 24 indicates the discharge flow rate corresponding to each drive setting value. The conversion table 621 associates each drive setting value with the discharge flow rate corresponding to that drive setting value.

[0045] As shown in FIG. 2, when the motor 41 is driven based only on the drive setting value associated with the set flow rate F (target flow rate), the error between the set flow rate F and the discharge flow rate becomes large. This is because the motor 41 and the drive force transmission mechanism 43 are not provided with a reducer. For example, when an operator discharges 5 μL (target amount) of fluid from the syringe 3, the operator sets the set flow rate F to 5 μL / min. However, when the motor 41 is driven for one minute based only on the drive setting value "4" associated with the set flow rate F "5 μL / min", the amount of fluid discharged from the syringe 3 (discharge amount) is 4.71 μL, and the error of the actual discharge amount from the target amount is 5.89%.

[0046] Next, the process executed by the control unit 63 will be described with reference to Fig. 1(a) to Fig. 4(a). Fig. 3 is a flowchart showing the process executed by the control unit 63 included in the syringe drive device 2 of this embodiment. Fig. 4(a) is a diagram showing the flow rate of the fluid discharged from the syringe 3 (discharge flow rate).

[0047] The process shown in Fig. 3 starts in response to an instruction to start rotating the motor 41 after the operator operates the operation unit 61 to set a set flow rate F (target flow rate). As shown in Fig. 3, in response to the instruction to start rotating the motor 41, the control unit 63 executes a set value determination process. Specifically, the control unit 63 determines a first set value and a second set value based on the set flow rate F (step S1).

[0048] In detail, the control unit 63 refers to the conversion table 621 and determines a drive setting value corresponding to a discharge flow rate greater than the set flow rate F as the first setting value, and determines a drive setting value corresponding to a discharge flow rate smaller than the set flow rate F as the second setting value. In this embodiment, the control unit 63 determines, from among the settable drive setting values, a drive setting value corresponding to a discharge flow rate greater than the set flow rate F and closest to the set flow rate F as the first setting value. In addition, the control unit 63 determines, from among the settable drive setting values, a drive setting value corresponding to a discharge flow rate smaller than the set flow rate F and closest to the set flow rate F as the second setting value.

[0049] For example, when the set flow rate F is 5 μL / min, the discharge flow rate that is greater than the set flow rate F and closest to the set flow rate F is 5.88 μL / min, so the control unit 63 determines the drive setting value "5" corresponding to the discharge flow rate "5.88 μL / min" as the first set value. Also, when the set flow rate F is 5 μL / min, the discharge flow rate that is smaller than the set flow rate F and closest to the set flow rate F is 4.71 μL / min, so the control unit 63 determines the drive setting value "4" corresponding to the discharge flow rate "4.71 μL / min" as the second set value.

[0050] Hereinafter, the discharge flow rate corresponding to the first set value may be referred to as the "first discharge flow rate F(H)." Similarly, the discharge flow rate corresponding to the second set value may be referred to as the "second discharge flow rate F(L)."

[0051] After determining the first set value and the second set value, the control unit 63 executes a division process. Specifically, the control unit 63 divides the unit time into a first period T1 and a second period T2 based on the value of the first discharge flow rate F(H), the value of the second discharge flow rate F(L), and the value of the set flow rate F (step S2). In other words, the control unit 63 determines the first period T1 and the second period T2. The unit time is, for example, 60 seconds.

[0052] 4(a), the control unit 63 calculates a first differential flow rate DF1 indicating the difference between the first discharge flow rate F(H) and the set flow rate F, and a second differential flow rate DF2 indicating the difference between the second discharge flow rate F(L) and the set flow rate F. Then, the control unit 63 divides the unit time into a first period T1 and a second period T2 based on the ratio between the first differential flow rate DF1 and the second differential flow rate DF2. For example, the control unit 63 may divide the unit time into the first period T1 and the second period T2 based on the following formula: F(H)-F:FF(L)=T1:T2

[0053] After determining the first period T1 and the second period T2, the control unit 63 executes a division control process to drive the motor 41 for a unit time. Specifically, the control unit 63 controls the motor 41 based on the second set value in the first period T1. The control unit 63 also controls the motor 41 based on the first set value in the second period T2 (step S3). As a result, the process shown in FIG. 3 is completed.

[0054] Specifically, as shown in FIG. 4(a), the control unit 63 first transmits the second set value to the motor driving unit 42. As a result, the motor driving unit 42 controls the motor 41 based on the second set value, and the fluid is discharged from the syringe 3 at the second discharge flow rate F(L). When the first period T1 has elapsed since the control unit 63 transmitted the second set value, the control unit 63 transmits the first set value to the motor driving unit 42. As a result, the motor driving unit 42 controls the motor 41 based on the first set value, and the fluid is discharged from the syringe 3 at the first discharge flow rate F(H). When the second period T2 has elapsed since the control unit 63 transmitted the first set value, the control unit 63 controls the motor driving unit 42 to stop the rotation of the motor 41. In other words, when a unit time has elapsed since the control unit 63 transmitted the second set value, the control unit 63 stops the rotation of the motor 41.

[0055] For example, when the set flow rate F is 5 μL / min and the unit time is 60 seconds, the first discharge flow rate F(H) is 5.88 μL / min and the second discharge flow rate F(L) is 4.71 μL / min, so the first differential flow rate DF1 is 0.88 and the second differential flow rate DF2 is 0.29. In this case, the control unit 63 may round off the decimal points to determine the first period T1 to be 45 seconds and the second period T2 to be 15 seconds.

[0056] Next, the amount of fluid discharged from the syringe 3 will be described with reference to Fig. 4(b). Fig. 4(b) is another diagram showing the flow rate of the fluid discharged from the syringe 3. Hereinafter, the amount of fluid discharged from the syringe 3 may be referred to as the "discharge amount."

[0057] 4(b), the syringe 3 discharges the fluid at the second discharge flow rate F(L) from time t1 to time t2 (first period T1). Therefore, during the first period T1, the discharge amount is less by the amount V1 of the fluid discharged at the second differential flow rate DF2(FF(L)) than when the fluid is discharged from the syringe 3 at the set flow rate F. Hereinafter, the amount V1 of the fluid may be referred to as the "first differential amount V1."

[0058] Meanwhile, the syringe 3 discharges the fluid at the first discharge flow rate F(H) from time t2 to time t3 (second period T2). Therefore, during the second period T2, the discharge amount is greater by the amount V2 of the fluid discharged at the first differential flow rate DF1 (F(H)-F) than when the fluid is discharged from the syringe 3 at the set flow rate F. Hereinafter, the amount V2 of the fluid may be referred to as the "second differential amount V2."

[0059] Since the first period T1 and the second period T2 are determined by the ratio between the first differential flow rate DF1 and the second differential flow rate DF2, the first differential amount V1 and the second differential amount V2 are equal. Therefore, according to this embodiment, the discharge amount can be made the same as that when the fluid is discharged from the syringe 3 at the set flow rate F.

[0060] An embodiment of the present invention has been described above with reference to the drawings (FIGS. 1(a) to 4(b)). According to this embodiment, the control unit 63 executes the set value determination process (step S1 in FIG. 3), the division process (step S2 in FIG. 3), and the division control process (step S3 in FIG. 3), thereby making it possible to eject from the syringe 3 an amount of fluid that is approximately the same as that when the syringe 3 is driven based on the target flow rate. Thus, even without providing a reducer, it is possible to suppress an error from the target amount. In other words, even without providing a reducer, it is possible to suppress a decrease in quantitative accuracy. Thus, it is possible to omit the reducer. And, it is possible to make the syringe drive device 2 more compact by the amount that the reducer is omitted.

[0061] Furthermore, pulsation is likely to occur when the flow rate is changed while the fluid is being discharged from the syringe 3. In contrast, according to this embodiment, the control unit 63 drives the motor 41 based on a drive set value (first set value) corresponding to a discharge flow rate that is greater than the set flow rate F and closest to the set flow rate F, and a drive set value (second set value) corresponding to a discharge flow rate that is smaller than the set flow rate F and closest to the set flow rate F, so that pulsation can be suppressed.

[0062] The present invention is not limited to the above-mentioned embodiment, and can be implemented in various aspects without departing from the gist of the present invention. In addition, the components disclosed in the above-mentioned embodiment can be modified as appropriate. For example, some of all the components shown in one embodiment may be added to the components of another embodiment, or some of all the components shown in one embodiment may be deleted from the embodiment.

[0063] The drawings are mainly schematic illustrations of each component to facilitate understanding of the invention, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of creating the drawings. Furthermore, the configurations of each component shown in the above embodiment are merely examples and are not particularly limited, and it goes without saying that various modifications are possible within a range that does not substantially deviate from the effects of the present invention.

[0064] For example, in the embodiment described with reference to Figures 1(a) to 4(b), the syringe drive device 2 drives the syringe 3 only for a unit time, but the syringe drive device 2 may also drive the syringe 3 periodically.

[0065] In the embodiment described with reference to Figs. 1(a) to 4(b), the control device 6 is provided with the operation unit 61, but the control device 6 may have a communication unit that communicates with an external terminal in addition to or instead of the operation unit 61. In this case, the communication unit may receive input data indicating the set flow rate F from the external terminal. The communication unit may include, for example, a wireless LAN board or a wired LAN board. The external terminal may be an information processing device such as a personal computer (PC), a tablet PC, or a smartphone.

[0066] 1(a) to 4(b), the control unit 63 determines, as the first set value, a drive setting value corresponding to a discharge flow rate that is greater than the set flow rate F and closest to the set flow rate F among the settable drive setting values, but the first set value may be any drive setting value that corresponds to a discharge flow rate greater than the set flow rate F. Similarly, in the present embodiment, the control unit 63 determines, as the second set value, a drive setting value corresponding to a discharge flow rate that is smaller than the set flow rate F and closest to the set flow rate F among the settable drive setting values, but the second set value may be any drive setting value that corresponds to a discharge flow rate smaller than the set flow rate F. [Industrial Applicability]

[0067] The syringe drive device according to the present invention is useful for syringe pumps that require high quantitative accuracy, such as syringe pumps that supply sample liquid to microchannels. [Explanation of symbols]

[0068] 2: Syringe drive device 3: Syringe 31: Cylindrical body 32: Plunger 41: Motor 63: Control section DF1: 1st differential flow rate DF2: 2nd differential flow rate F: Set flow rate (target flow rate) F(H): 1st discharge flow rate (1st flow rate) F(L):Second discharge flow rate (second flow rate) T1: First period T2: Second period

Claims

1. A syringe drive device that drives a syringe to eject a fluid from the syringe, A motor that drives the syringe; a control unit that drives the motor based on a set value to control a flow rate that indicates the amount of the fluid discharged from the syringe per unit time; Equipped with the control unit divides the unit time into a first period and a second period based on a first flow rate indicating a flow rate corresponding to a first set value, a second flow rate indicating a flow rate corresponding to a second set value, and a target flow rate indicating a target value of the flow rate; The first flow rate indicates a flow rate that is greater than the target flow rate, The second flow rate indicates a flow rate that is smaller than the target flow rate, The control unit controls the motor based on the second setting value during the first period, and controls the motor based on the first setting value during the second period.

2. 2. The syringe drive device according to claim 1, wherein the control unit divides the unit time into the first period and the second period based on a ratio between a first differential flow rate indicating a difference between the first flow rate and the target flow rate and a second differential flow rate indicating a difference between the second flow rate and the target flow rate.

3. the first set value indicates a set value corresponding to a flow rate that is greater than the target flow rate and closest to the target flow rate, among the settable set values; 3 . The syringe drive device according to claim 1 , wherein the second set value indicates a set value corresponding to a flow rate that is smaller than the target flow rate and closest to the target flow rate, among the settable set values.

4. The syringe comprises: a cylinder that contains the fluid and is connected to a microchannel through which the contained fluid flows; A gasket that is slidable inside the cylindrical body; A plunger connected to the gasket; having The syringe drive device according to claim 1 , wherein the motor drives the plunger.

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