JP6508931B2 - Liquid delivery drive - Google Patents

Description

  The present invention relates to, for example, a liquid delivery drive device for medical use, such as a syringe pump and an infusion pump.

As an example of a liquid delivery drive device, a syringe pump is known which moves a pusher along an inner cylinder of a syringe to push out the liquid contained in the syringe. However, when the syringe is replaced and used repeatedly, the load changes due to the wear of the mechanism provided in the syringe pump and the deterioration with the passage of time.
Also, if the tube attached to the tip of such a syringe pump is bent or the like, the load at the time of solution injection increases. A syringe pump has been proposed which detects this change in load according to the signal level of the reflective photosensor (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 7-136258

  However, with the technology described in Patent Document 1, even if it is possible to detect a change in load when using a syringe pump, it is possible to detect an abnormality in the load due to wear of mechanical parts possessed by the syringe pump and temporal deterioration due to use. could not.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a liquid delivery drive device that detects a change in load due to wear and deterioration with time of use of the liquid delivery drive device.

In the liquid delivery drive device according to one aspect of the present invention, a motor, a drive transmission member transmitting a rotation of the motor to a load, a drive circuit driving the motor, and the drive transmission member driven by the motor A sensor that detects a value related to a load torque of the motor as a detected value when being driven, a storage unit, and the detected value when the initial power is turned on is stored in the storage unit as a first detected value, The first detection value is compared with the second detection value using the detection value when the power is turned on after the power-on as the second detection value, and the first detection value is compared with the second detection value. A control unit for outputting the result of the detection , and the control unit detects the first detection value at each predetermined position when the initial power is turned on, and stores the first detection value at each predetermined position. Stored in the When the power is turned on after turning on the power, the second detection value is detected at each of the predetermined positions, and the second detection value is stored in the storage unit at each of the predetermined positions. Each time the first detection value and the second detection value are compared, and the result of comparing the first detection value at the same position and the second detection value increases by a first predetermined amount or more, an error occurs. Output a signal indicating.

  According to the present invention, it is possible to detect a change in load due to wear of the liquid delivery drive device and deterioration with time due to use.

It is a top view which shows the state which attached the syringe to the liquid delivery drive device which concerns on each embodiment. It is a block diagram explaining the circuit composition of the liquid delivery drive device concerning each embodiment. It is a flowchart which shows an example of the flow of the process in the initial mode of the control part which concerns on each embodiment. It is a figure explaining the initial stage no-load torque of a motor in each position from position p1 of a carriage concerning each embodiment to position pn. It is a flowchart which shows an example of the flow of the process in the inspection mode of the control part which concerns on 1st Embodiment. It is a figure explaining the no load torque at the time of inspection B (k) concerning a 1st embodiment. It is a figure explaining the relationship between the calculation result of the difference of the no-load torque for inspection B (k) and the initial no-load torque A (k) according to the first embodiment, and the predetermined value P. It is a flowchart which shows an example of the flow of a process of a control part when a syringe is mounted | worn with the liquid delivery drive device which concerns on 2nd Embodiment. It is a figure explaining the relationship between initial stage no-load torque A (k) and syringe load torque C (k) which concern on 2nd Embodiment. It is a figure explaining the relationship between the difference of syringe load torque C (k) and initial stage no-load torque A (k) which concerns on 2nd Embodiment, and the predetermined value Q. FIG. It is a figure explaining the relationship between the identification information of a syringe memorize | stored in the memory | storage part which concerns on 2nd Embodiment, the information which shows a start position, and predetermined value Q. FIG.

First Embodiment
Hereinafter, the present embodiment will be described with reference to the drawings.
FIG. 1 is a plan view showing a state in which the syringe 2 is attached to the liquid delivery drive device 1 according to the present embodiment. In the present embodiment, a syringe pump will be described as an example to which the liquid delivery drive device 1 is applied.

The outline of the configuration of the liquid delivery drive device 1 will be described with reference to FIG.
As shown in FIG. 1, the liquid delivery drive device 1 includes a housing 100, a motor 101, a sensor magnet 102, an encoder 103, a drive circuit board 104, and a first attachment plate 105. The liquid delivery drive device 1 includes a first gear 107, a second gear 108, a lead screw 109, a second mounting plate 110, a carriage 111, a guide rod 112, a control unit 113, a storage unit 114, a drive circuit 115, and a slider 120. Have. The motor 101 comprises a shaft 106. The slider 120 includes a detection unit 121.

  Further, as shown in FIG. 1, the syringe 2 includes a pusher 204 and a barrel tip 206. The tube 3 is attached to the tube tip 206.

The motor 101 is connected to the drive circuit board 104 via a cable 141. Also, the motor 101 is attached to the first mounting plate 105.
The sensor magnet 102 is attached to the short tip 106 B of the shaft 106.
The first gear 107 is press-fitted to the long tip 106 A of the shaft 106.

  The encoder 103, the control unit 113, the storage unit 114, and the drive circuit 115 are attached to the drive circuit board 104. As shown in FIG. 1, the encoder 103 is attached at a position facing the sensor magnet 102. Furthermore, an interface terminal 131 is attached to the drive circuit board 104.

  The lead screw 109 is rotatably attached to the first mounting plate 105 and the second mounting plate 110. In addition, a second gear 108 is attached to an end of the lead screw 109 on the first attachment plate 105 side. The second gear 108 is assembled in mesh with the first gear 107.

  The carriage 111 is assembled to the lead screw 109. The lead screw 109 is rotated by the motor 101 via the second gear 108 and the first gear 107. The carriage 111 moves on the lead screw 109 as the lead screw 109 rotates. When the solution stored in the syringe 2 is pushed out to the tube 3, the carriage 111 moves in the direction from the second mounting plate 110 toward the first mounting plate 105.

  One end of the guide rod 112 is attached to the carriage 111. The other end of the guide bar 112 is attached to the slider 120.

  The detection unit 121 outputs, to the control unit 113, information indicating that the opening 205 has been attached to the slit 122.

  In FIG. 1, the position where the carriage 111 contacts the second mounting plate 110 is p1, and the position where the carriage 111 contacts the first mounting plate 105 is pn. Further, the position of the carriage 111 in the initial state in which the syringe 2 is attached to the liquid delivery drive device 1 is taken as pc. In the following description, the position is the position of the carriage 111.

  In the example shown in FIG. 1, the lead screw 109 and the carriage 111 are used as the moving mechanism, but the invention is not limited thereto. The moving mechanism may be configured of, for example, a rack and a pinion gear.

Next, the circuit configuration of the liquid delivery drive device 1 will be described with reference to FIG.
FIG. 2 is a block diagram for explaining the circuit configuration of the liquid delivery drive device 1 according to the embodiment. As shown in FIG. 2, the liquid delivery drive device 1 includes a motor 101, an encoder 103, a control unit 113, a storage unit 114, a drive circuit 115, a detection unit 121, and an interface terminal 131.
In addition, the liquid delivery drive device 1 is connected to the power supply unit 301, the operation unit 303, and the notification unit 304 via the interface terminal 131.

  The operation unit 303 detects an operation by the user. The operation includes, for example, an operation indicating whether or not the motor 101 is to be rotated, an operation in the rotation direction of the motor 101, and the like.

The notification unit 304 receives information sg3 indicating an error from the control unit 113 via the interface terminal 131. The notification unit 304 notifies an error based on the received information sg3. The notification unit 304 is at least one of a display device, an acoustic signal output device, and a light emitting device.
In the present embodiment, although a case where the notification unit 304 notifies an error based on the information sg3 indicating an error will be described, the present invention is not limited to this. The control unit 113 may be configured to output information indicating that the liquid delivery drive device 1 is in a normal state, instead of the information sg3 indicating an error or in addition to the information sg3 indicating an error. In this configuration, the notification unit 304 indicates that the liquid delivery drive device 1 is in the normal state based on the fact that the control unit 113 outputs the information indicating that the liquid delivery drive device 1 is in the normal state. Inform. In addition, the notification unit 304 may be configured to notify an error based on the fact that the control unit 113 no longer outputs information in a normal state.

The reset switch 305 is a switch for initializing the information stored in the storage unit 114 of the liquid delivery drive device 1. The reset switch 305 is operated, for example, by a service person after maintenance.
The drive circuit 115 generates a drive signal based on the drive instruction value input from the control unit 113, and drives the motor 101 by the generated drive signal.
The motor 101 is driven by a drive circuit 115. The motor 101 is, for example, a stepping motor.

  The encoder 103 detects a change in the magnetic field generated by the rotation of the sensor magnet 102, and outputs the detected value to the control unit 113. The encoder 103 includes, for example, a magnetic sensor and a magnetic encoder. The magnetic sensor is, for example, a Hall element.

  The interface terminal 131 is a terminal for supplying power to the drive circuit board 104, outputting information, and inputting information.

  The storage unit 114 is a non-volatile memory. The information stored in the storage unit 114 will be described later.

The control unit 113 is, for example, a CPU (central processing unit). Control unit 113 detects an operation by the user according to instruction signal sg2 input from operation unit 303, and performs control according to the detected operation result.
Further, the control unit 113 operates the motor 101 via the drive circuit 115. The control unit 113 acquires the load torque of the motor 101. The load torque changes in accordance with the position of the carriage 111 which changes with the operation of the motor 101. The control unit 113 compares, for each position of the carriage 111, the load torque obtained in the initial state of the liquid delivery drive device 1 with the load torque obtained by obtaining the operation of the motor 101 after the initial state. To detect load abnormalities due to wear of mechanical parts and deterioration with time due to use. Here, the load is each component from the motor 101 to the slider 120. Specifically, the load is the first gear 107, the second gear 108, the lead screw 109, the carriage 111, the guide rod 112, and the slider 120. Hereinafter, details of load abnormality detection by the control unit 113 will be described.

Here, first, acquisition of the load torque by the control unit 113 in the initial state of the liquid delivery drive device 1 will be described. Next, acquisition of load torque by the control unit 113 and detection of load abnormality after the initial state of the liquid delivery drive device 1 will be described.
In this embodiment, as a specific example of the “initial state” of the liquid delivery drive device 1, the case where the liquid delivery drive device 1 is powered on for the first time after the liquid delivery drive device 1 is assembled at a factory or the like will be described. . In the following description, the application of power to the liquid delivery drive device 1 in the initial state is referred to as initial power-on. Further, the operation mode of the control unit 113 in the initial state is referred to as an initial mode.
In the following description, the state after the initial state of the liquid delivery drive device 1 is referred to as a normal state. In the normal state, the operation mode of the control unit 113 that operates the motor 101 in a state in which the syringe 2 is not attached to the liquid delivery drive device 1 is referred to as an inspection mode.

[Process of control unit 113 in initial mode]
In the initial mode, the control unit 113 acquires the load torque of the motor 101 in a state in which the syringe 2 is not attached to the liquid delivery drive device 1, and stores the acquired load torque in the storage unit 114. In the following description, a state in which the syringe 2 is not attached to the liquid delivery drive device 1 is referred to as a no-load state. Further, the load torque of the motor 101 in the initial state of the liquid delivery drive device 1 is referred to as an initial no-load torque or a first detection value.

  In the initial mode, the control unit 113 acquires an initial no-load torque of the motor 101, and stores the acquired initial no-load torque in the storage unit 114. Here, the control unit 113 acquires an initial no-load torque for each position of the carriage 111 which moves according to the operation of the motor 101. A specific example in which the control unit 113 acquires the initial no-load torque for each position of the carriage 111 will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a flowchart showing an example of the flow of processing in the initial mode of the control unit 113 according to the present embodiment. The following processing is performed, for example, when the liquid delivery drive device 1 is shipped from the factory.

(Step S1) When the liquid delivery drive device 1 is powered on for the first time, the control unit 113 sets the operation mode to the initial mode.
The control unit 113 may store information indicating that the power has been turned on in the storage unit 114 in step S1. As a result, the control unit 113 can determine whether it is the first activation or the second or subsequent activation based on whether or not the storage unit 114 stores information indicating that the power has been turned on.

(Step S2) The control unit 113 outputs a pulse signal of a predetermined number of pulses to the drive circuit 115 to drive the motor 101. Thus, the carriage 111 moves to a position corresponding to the number of pulses of the pulse signal output from the control unit 113. In this example, the control unit 113 moves the carriage 111 by setting the movement start position of the carriage 111 to the position p1 shown in FIG. 1 and setting the movement end position of the carriage 111 to the position pn. The movement start position may be the position pn, and the movement end position may be the position p1.
Here, an example of the initial no-load torque of the motor 101 when the carriage 111 is moved from the position p1 to the position pn is shown in FIG.

  FIG. 4 is a diagram for explaining the initial no-load torque of the motor 101 at each position from the position p1 of the carriage 111 to the position pn. In the figure, the horizontal axis indicates the position pk of the carriage 111, and the vertical axis indicates the load torque of the motor 101. However, 1 ≦ k ≦ n for the subscript k and the subscript n. A curve g201 shown in the figure indicates the magnitude of the initial no-load torque A at each position from the position p1 to the position pn. Here, the magnitude of the initial no-load torque at the position pk of the carriage 111 is referred to as an initial no-load torque A (k). As an example, the value of the initial no-load torque at the position p1 is the initial no-load torque A (1). Also, as an example, the value of the initial no-load torque at the position pn is the initial no-load torque A (n).

(Step S3) While moving the carriage 111 from the position p1 to the position pn, the control unit 113 acquires the load torque of the motor 101 for each position of the carriage 111. Specifically, when the carriage 111 is at the position pk, the control unit 113 acquires the initial no-load torque A (k).

(Step S4) The control unit 113 stores the initial no-load torque A (k) acquired at step S3 and the position pk of the carriage 111 at the time of acquisition of the initial no-load torque A (k) in the storage 114 Let

(Step S5) The control unit 113 determines whether the carriage 111 has reached the movement end position, that is, the position pn. If the control unit 113 determines that the carriage 111 has not reached the position pn (step S5; NO), the process returns to step S3. In addition, when the control unit 113 determines that the carriage 111 has reached the position pn (step S5; YES), the processing of the initial mode ends.
The initial no-load torque A (k) corresponding to the position pk of the carriage 111 is stored in the storage unit 114 by the processing of the control unit 113 described above.

[Process of control unit 113 in inspection mode]
In the inspection mode, the control unit 113 obtains the load torque of the motor 101 in a state where the syringe 2 is not attached to the liquid delivery drive device 1. Further, the control unit 113 compares the acquired load torque with the initial no-load torque acquired in advance, and outputs the comparison result to the notification unit 304. In the following description, the load torque of the motor 101 in the inspection mode is referred to as an inspection no-load torque or a second detection value.

  In the inspection mode, the control unit 113 compares the acquired inspection no-load torque with the initial no-load torque stored in advance in the storage unit 114. Here, the control unit 113 performs acquisition of inspection no-load torque and comparison between the acquired inspection no-load torque and initial no-load torque for each position of the carriage 111 that moves according to the operation of the motor 101. . A specific example of the process of the control unit 113 in the inspection mode will be described with reference to FIGS. 5, 6, and 7.

  FIG. 5 is a flowchart illustrating an example of the flow of processing in the inspection mode of the control unit 113 according to the present embodiment. The following processing is performed, for example, before using the liquid delivery drive device 1. More specifically, the following process is performed after the liquid delivery drive device 1 is shipped from the factory and before the syringe 2 is attached to the liquid delivery drive device 1.

(Step S101) The control unit 113 sets the operation mode to the inspection mode.
The control unit 113 may start the process in the inspection mode only when it is determined based on the output of the detection unit 121 that the syringe 2 is not attached.

(Step S102) The control unit 113 reads out all of the initial no-load torque A (k) stored in the storage unit 114 from the position p1 to the position pn. That is, the control unit 113 reads from the initial no-load torque A (1) to the initial no-load torque A (n) from the storage unit 114.

(Step S103) The control unit 113 drives the motor 101 to move the carriage 111, as in step S2 in the initial mode. That is, the control unit 113 moves the carriage 111 with the movement start position of the carriage 111 at the position p1 shown in FIG. 1 and the movement end position of the carriage 111 at the position pn.

  Here, an example of the no-load torque at the time of inspection of the motor 101 when the carriage 111 is moved from the position p1 to the position pn is shown in FIG.

  FIG. 6 is a diagram for explaining the no-load torque at the time of inspection of the motor 101 at each position from the position p1 of the carriage 111 to the position pn. In the figure, the horizontal axis indicates the position pk of the carriage 111, and the vertical axis indicates the load torque of the motor 101. However, 1 ≦ k ≦ n for the subscript k and the subscript n. A curve g211 shown in the figure indicates the magnitude of the no-load torque B during inspection at each position from the position p1 to the position pn. Here, the magnitude of the no-load torque upon inspection at the position pk of the carriage 111 is referred to as no-load torque upon inspection B (k). As an example, the magnitude of the no-load torque upon inspection at the position p1 is the no-load torque upon inspection B (1). Further, as an example, the magnitude of the no-load torque at the time of inspection at the position pn is the no-load torque at the time of inspection B (n).

(Step S104) While moving the carriage 111 from the position p1 to the position pn, the control unit 113 acquires the load torque of the motor 101 for each position of the carriage 111. Specifically, when the carriage 111 is at the position pk, the control unit 113 acquires the no-load torque at inspection B (k).
The control unit 113 stores the acquired inspection no-load torque B (k) and the information indicating the position pk of the carriage 111 at the time of acquisition of the inspection no-load torque B (k) in the storage 114 You may

(Step S105) The control unit 113 compares the inspection no-load torque B (k) acquired in step S104 with the initial no-load torque A (k) read from the storage unit 114. Specifically, the control unit 113 subtracts the magnitude of the initial no-load torque A (k) read from the storage unit 114 from the magnitude of the inspection no-load torque B (k) acquired in step S104. Subsequently, the control unit 113 determines whether the value obtained by the subtraction is larger than a predetermined value P, which is a determination threshold. The predetermined value P is, for example, a value indicating the magnitude of the maximum rated load torque including the motor 101 and the load when the syringe 2 is not attached to the liquid delivery drive device 1. As an example, the predetermined value P is stored in advance in the storage unit 114 before the liquid delivery drive device 1 is shipped from the factory. The difference between the initial no-load torque A (k) and the no-load torque B (k) at the time of inspection and the predetermined value P will be described with reference to FIG.

FIG. 7 shows the relationship between the calculation result of the difference between the no-load torque B (k) during inspection and the initial no-load torque A (k) at each position from the position p1 to the position pn of the carriage 111 and the predetermined value P. FIG. In the figure, the horizontal axis indicates the position pk of the carriage 111, and the vertical axis indicates the load torque of the motor 101. The curve g221 in FIG. 7 is a difference {B (k) obtained by subtracting the magnitude of the initial no-load torque A (k) from the magnitude of the no-load torque B (k) during inspection when the carriage 111 is at the position pk. -A (k)} is represented. For example, at the position p1, the difference is {B (1) -A (1)}. Further, a broken line g222 in FIG. 7 represents a predetermined value P.
In the case of the example shown in FIG. 7, the difference {B (k) -A (k)} is equal to or less than the predetermined value P at any position pk.

  Referring back to FIG. 5, when the control unit 113 determines that the value obtained by subtracting the magnitude of the initial no-load torque A (k) from the magnitude of the no-load torque B (k) during inspection is equal to or less than the predetermined value P. (Step S105; NO), the process proceeds to step S106. When controller 113 determines that the value obtained by subtracting the magnitude of initial no-load torque A (k) from the magnitude of inspection no-load torque B (k) is greater than predetermined value P (step S105; YES) The process proceeds to step S107.

(Step S106) The control unit 113 determines whether the carriage 111 has reached the movement end position, that is, the position pn. If the control unit 113 determines that the carriage 111 has not reached the position pn (step S106; NO), the process returns to step S104. In addition, when the control unit 113 determines that the carriage 111 has reached the position pn (step S106; YES), the processing in the inspection mode ends.

(Step S 107) The control unit 113 outputs information indicating a load abnormality, that is, an error, to the notification unit 304 via the interface terminal 131. After the notification, the control unit 113 ends the process of the inspection mode.

  As described above, the control unit 113 according to the present embodiment detects the temporal change of the load based on the comparison result of the initial no-load torque A (k) and the no-load torque B (k) at the time of inspection. Do. As a result, according to the liquid delivery drive device 1 of the present embodiment, it is possible to detect an abnormality in the load due to wear of the mechanical component of the syringe pump and deterioration with time due to use.

[Modification]
In the example shown in FIG. 5, although an example in which load abnormality detection is performed for each position pk of the carriage 111 has been described, the present invention is not limited thereto. The control unit 113 stores the initial no-load torque A (k) stored in the storage unit 114 after the acquisition of the no-load torque B (k) for inspection is completed for each position pk from the movement start position to the movement end position. And the no-load torque B (k) at the time of inspection may be sequentially read and compared for each position pk.

  Also, in the example shown in FIG. 5, an example in which the load abnormality is detected by subtracting the initial no-load torque A (k) from the no-load torque B (k) at the time of inspection has been described. Absent. The control unit 113 is not limited to subtraction, and compares with a predetermined value P using any of a ratio, a difference between average values of predetermined intervals, a ratio of average values of predetermined intervals, and another statistical method. Anomaly detection may be performed. In this case, the predetermined value P is a value set in advance according to the method to be used.

  In FIG. 5, even if the value obtained by subtracting the initial no-load torque A (k) from the no-load torque B (k) at the time of inspection is equal to or less than a predetermined value P, the no-load torque B (k) at the time The value and the predetermined value R may be further compared. Here, the predetermined value R is a value smaller than the predetermined value P, and may be, for example, a value used in an inspection performed at the time of shipping. In this case, when the subtracted value is larger than the predetermined value R, the control unit 113 may output information indicating an error to the notification unit 304 via the interface terminal 131.

  In the present embodiment, the example of performing load abnormality detection using the initial no-load torque A (k) in the entire range from the movement start position to the movement end position of the carriage 111 has been described, but the present invention is limited thereto. Absent. The storage unit 114 may perform load abnormality detection using, for example, the initial no-load torque A (k) in the range of one rotation of the lead screw 109. In this case, the control unit 113 uses the initial no-load torque A (k) for one rotation of the lead screw 109 stored in the storage unit 114 to calculate the initial no-load torque A (j) at another position pj. It may be estimated. As described above, the reason why only the initial no-load torque A (k) for one rotation of the lead screw 109 may be stored is because the initial state before shipment is the initial state. This is because it is assumed that the variation of (k) is small.

Second Embodiment
In the second embodiment, an example will be described in which an abnormality in the load is detected in the use state of the liquid delivery drive device 1, that is, in the state where the syringe 2 is attached to the liquid delivery drive device 1.
The configurations of the liquid delivery drive device 1 and the syringe 2 are the same as those of the first embodiment described above. About the part the same as that of 1st Embodiment mentioned above, or corresponding, description is abbreviate | omitted using the same code | symbol.
In the first embodiment, the control unit 113 detects a load abnormality by comparing the no-load torque in the initial state before factory shipment with the no-load torque after the elapse of time from the initial state. That is, in the first embodiment, the load torques in a state in which the syringe 2 is not attached to the liquid delivery drive device 1 are compared with each other. On the other hand, in the second embodiment, the control unit 113 detects a load abnormality by comparing the no-load torque in the initial state with the load torque in the state where the syringe 2 is attached to the liquid delivery drive device 1. . That is, the second embodiment is different from the first embodiment in that the load abnormality can be detected even when the syringe 2 is attached. In the following description, the operation mode of the control unit 113 for operating the motor 101 in a state where the syringe 2 is attached to the liquid delivery drive device 1 is referred to as a syringe use mode or simply a use mode. Further, among the load torques in a state where the syringe 2 is attached to the liquid delivery drive device 1, the load torque at the position pk is referred to as a syringe load torque C (k) or a third detection value.

[Process of control unit 113 in usage mode]
A specific example of the process of the control unit 113 in the use mode will be described with reference to FIGS. 8, 9 and 10.
FIG. 8 is a flowchart showing an example of the flow of processing of the control unit 113 when the syringe 2 is attached to the liquid delivery drive device 1 according to the present embodiment. In the state where the syringe 2 is attached to the liquid delivery drive device 1, the case where the infusion start position of the syringe 2 is constant at the position p1 regardless of the type of the syringe 2 will be described. An example in which the infusion start position of the syringe 2 changes between the position p1 and the position pn depending on the type of the syringe 2 will be described later in a modified example.
Further, in the present embodiment, it is assumed that the initial no-load torque A (k) acquired by the control unit 113 in the initial mode is stored in the storage unit 114.

(Step S200) The control unit 113 sets the operation mode to the use mode.
The control unit 113 may set the operation mode to the use mode only when it is determined that the syringe 2 is attached based on the output of the detection unit 121.

(Step S201) As in step S102 in the inspection mode, the control unit 113 reads out all of the initial no-load torque A (k) from the position p1 to the position pn from the storage unit 114. That is, the control unit 113 reads from the initial no-load torque A (1) to the initial no-load torque A (n) from the storage unit 114.

(Step S202) The control unit 113 drives the motor 101 to move the carriage 111, as in step S2 in the initial mode. That is, the control unit 113 moves the carriage 111 with the movement start position of the carriage 111 at the position p1 shown in FIG. 1 and the movement end position of the carriage 111 at the position pn.

(Step S203) The control unit 113 acquires the syringe load torque C (k) at the position pk of the carriage 111. Here, an example of the syringe load torque C (k) of the motor 101 when the carriage 111 is moved from the position p1 to the position pn is shown in FIG.

FIG. 9 is a view for explaining the relationship between the initial no-load torque A (k) and the syringe load torque C (k) according to the second embodiment. In the figure, the horizontal axis indicates the position pk of the carriage 111, and the vertical axis indicates the load torque of the motor 101. However, 1 ≦ k ≦ n for the subscript k and the subscript n. A curve g201 shown in the figure indicates the magnitude of the initial no-load torque A (k) at the position k of the carriage 111. Further, a curve g301 shown in the figure indicates the magnitude of the syringe load torque C (k) at the position k of the carriage 111.
The movement start position pc1 and the movement start position pc2 of the carriage 111 will be described later in a modification.

(Step S204) The control unit 113 subtracts the initial load torque A (k) acquired in step S201 from the syringe load torque C (k) acquired in step S203 to obtain the difference {C (k) −A (k). ) To calculate. Next, the control unit 113 determines whether the calculated difference {C (k) −A (k)} is larger than a predetermined value Q.
Here, the relationship between the difference {C (k) −A (k)} between the syringe load torque C (n) and the initial no-load torque A (n) and the predetermined value Q will be described.

FIG. 10 is a view for explaining the relationship between the difference between the syringe load torque C (k) and the initial no-load torque A (k) according to the present embodiment and the predetermined value Q. In the figure, the horizontal axis indicates the position pk of the carriage 111, and the vertical axis indicates the load torque of the motor 101.
A curve g311 in FIG. 10 represents the difference {C (k) -A (k)} in the state where no load abnormality has occurred due to deterioration with time. A curve g311 'in FIG. 10 represents a difference {C (k) -A (k)} in a state where a load abnormality occurs due to deterioration with time. A broken line g312 in FIG. 10 represents a predetermined value Q.
The control unit 113 compares, for example, the value {C (2) −C (2)} subtracted with the predetermined value Q at the position p2, and the value subtracted is less than the predetermined value Q. Determine that it is normal. Also, when the load torque is the curve 311 ', the value {C (m) -A (m)} subtracted at the position pm is compared with the predetermined value Q, and the subtracted value is greater than the predetermined value Q Therefore, it is determined that the load torque is abnormal.
If the control unit 113 determines that the difference {C (k) −A (k)} is larger than the predetermined value Q (YES in step S204), the process proceeds to step S206. If the control unit 113 determines that the subtracted value {(C (k) −A (k))} is less than or equal to the predetermined value Q (step S204; NO), the process proceeds to step S205.

(Step S205) The control unit 113 determines whether the carriage 111 has reached the movement end position, that is, the position pn. If the control unit 113 determines that the carriage 111 has not reached the position pn (step S205; NO), the process returns to step S203. In addition, when the control unit 113 determines that the carriage 111 has reached the position pn (step S205; YES), the processing of the use mode ends.

(Step S206) The control unit 113 stops the drive of the motor 101 via the drive circuit 115. Subsequently, the control unit 113 outputs information indicating a load abnormality, that is, an error, to the notification unit 304 via the interface terminal 131. The control unit 113 may include information indicating the type of error in the information indicating the error. After the notification, the control unit 113 ends the process.

As described above, the control unit 113 of the present embodiment detects an abnormality in load torque in a state in which the syringe 2 is attached. That is, the load of the present embodiment includes the syringe 2 and the tube 3 in addition to the components from the motor 101 to the slider 120. Here, the tube 3 may be closed by an external force or the like. When the tube 3 is closed, the pressure loss inside the tube 3 is increased, so that the liquid inside the tube 3 becomes difficult to flow, so the load torque of the motor 101 is increased compared to the non-closed state. The control unit 113 of the present embodiment can detect this increase in load torque as a load abnormality. Further, since the load torque of the motor 101 is also increased by the blockage of the cylinder tip 206 of the syringe 2 or the deformation of the sliding portion of the syringe 2, the increase of the load torque can be detected as a load abnormality. That is, according to the liquid delivery drive device 1 of the present embodiment, not only an abnormality due to a temporal change of the liquid delivery drive device 1 but also an abnormality due to a change in the state of the syringe 2 or the tube 3 can be detected.
Further, according to the liquid delivery drive device 1 of the present embodiment, when an abnormality in the load torque is detected, the operation of the motor 101 is stopped, so that it is difficult to deliver the liquid when the tube 3 is closed etc. Can be stopped.

[Modification]
Next, a modification of the second embodiment will be described with reference to FIGS. 9 and 11. FIG. The stroke of the sliding portion may differ from one syringe 2 to another depending on the type and size of the syringe 2. That is, the syringe 2 having a relatively long stroke of the sliding portion and the syringe 2 having a relatively short stroke of the sliding portion exist. Therefore, depending on the type and size of the syringe 2, the movement start position pc of the carriage 111 may not be the position p1 shown in FIG. For example, in a certain syringe 2, the movement start position pc of the carriage 111 is the movement start position pc1 shown in FIG. Moreover, as for another syringe 2, the movement start position pc of the carriage 111 is the movement start position pc2 shown in FIG. If the movement start position pc is not constant, the control unit 113 correlates the movement start position pc with the position pk, whereby the initial no-load torque A (k) and the syringe load torque C (k) are obtained. You can compare with. The liquid delivery driving device 1 associates the movement start position pc with the position pk by storing the movement start position pc of the carriage 111 in advance in the storage unit 114 for each type and size of the syringe 2. I do.

  FIG. 11 is a diagram for explaining the relationship between the identification information of the syringe stored in the storage unit 114 according to the second embodiment, information indicating the start position, and the predetermined value Q. In the storage unit 114, identification information of the syringe 2 and the movement start position pc are stored in association with each other for each type and size of the syringe 2. The control unit 113 reads the movement start position pc from the storage unit 114 based on the identification information of the attached syringe 2. The control unit 113 associates the movement start position pc with the position pk based on the read movement start position pc. The identification information of the syringe 2 is the manufacturer name of the syringe 2, the model number of the syringe 2, or the like.

  Further, as shown in FIG. 11, the storage unit 114 may store the predetermined value Q described above for each identification information of the syringe 2. Thereby, the control unit 113 can determine the threshold value for determining the abnormality of the load, that is, the predetermined value Q in association with the type and the size of the syringe 2. Therefore, according to the liquid delivery drive device 1 of this modification, even if the magnitude of the syringe load torque C is not constant due to the type and size of the syringe 2 being not constant, the load torque abnormality is accurate It can be detected well.

  In the example shown in FIG. 8, an example has been described in which the initial no-load torque A (k) is subtracted from the syringe load torque C (k) and the value obtained by the subtraction is compared with a predetermined value Q to detect abnormality. Not limited to this. The control unit 113 is not limited to subtraction, and compares with a predetermined value Q using any of a ratio, a difference between average values of predetermined sections, a ratio of average values of predetermined sections, and another statistical method. Anomaly detection may be performed. In this case, the predetermined value Q is a value set in advance according to the method to be used.

  Further, in the example shown in FIG. 8, the example in which the syringe load torque C (k) and the initial no-load torque A (k) are compared has been described, but the present invention is not limited thereto. The control unit 113 may compare the syringe load torque C (k) with the no-load torque B (k) at the time of inspection. For example, the control unit 113 subtracts the inspection no-load torque B (k) at the same position from the syringe load torque C (k) and compares the subtracted value with the predetermined value S to perform abnormality detection. Good. The predetermined value S may be the same value as the predetermined value Q, or may be a value smaller than the predetermined value Q. Therefore, according to the liquid delivery drive device 1 of this modification, the difference from the syringe load torque C can be calculated based on the load torque after the change with time. That is, according to the liquid delivery drive device 1 of this modified example, it is possible to more accurately detect the change in load torque due to the presence or absence of the syringe 2.

  In the first and second embodiments, when the no-load torque B (k) at the time of inspection is larger than a predetermined value based on the initial no-load torque A (k), the control unit 113 Has described the case where an error is reported. That is, in each of the above-described embodiments, an example has been described in which the control unit 113 reports an error when the load torque increases, but the present invention is not limited to this. The control unit 113 generates an error when the inspection no-load torque B (k) is smaller than a predetermined value based on the initial no-load torque A (k), that is, when the load torque decreases. May be notified. As a specific example, the first gear 107 or the second gear 108 may come off the shaft. When these gears come off, the load torque decreases sharply as compared to before the gears come off. When a decrease in load torque is detected, the control unit 113 outputs information indicating an error to the notification unit 304 via the interface terminal 131.

  Also, in the first and second embodiments, the control unit 113 has described an example in which information sg3 indicating an error or information indicating a normal state is output to the notification unit 304. However, it is not limited to this. The control unit 113 can also output these pieces of information to a device external to the liquid delivery drive device 1. For example, the control unit 113 may output information sg3 indicating an error or information indicating a normal state to an apparatus having a CPU with higher performance.

  In the first and second embodiments, the load of the motor 101 is detected using the sensor magnet 102 and the encoder 103. However, the present invention is not limited to this. The load of the motor 101 may be detected by attaching a disk provided with a slit to the shaft 106 and using a photo sensor.

Moreover, although the syringe 2 was demonstrated as an example of load in 1st this embodiment-2nd embodiment, it is not restricted to this. The load may be driven via at least one of, for example, the first gear 107, the second gear 108, the lead screw 109, the carriage 111, the guide rod 112, and the like. The load may, for example, be a blood pump.
Moreover, although the example of a stepping motor was demonstrated as the motor 101 in 1st this embodiment-2nd embodiment, it is not restricted to this. The motor 101 may be an AC motor, a DC motor or the like.

  A program for realizing the function of the control unit 113 in the liquid delivery drive device 1 according to the present invention is recorded in a computer readable recording medium, and the program recorded in the recording medium is read into a computer system and executed. The procedure of each process may be performed by carrying out. Here, the “computer system” includes an OS and hardware such as peripheral devices. The "computer system" also includes a WWW system provided with a homepage providing environment or a display environment. The term "computer-readable recording medium" refers to a storage medium such as a flexible disk, a magneto-optical disk, a ROM, a portable medium such as a ROM or a CD-ROM, or a hard disk built in a computer system. Furthermore, the "computer-readable recording medium" is a volatile memory (RAM) in a computer system serving as a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those that hold the program for a certain period of time are also included.

  The program may be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the “transmission medium” for transmitting the program is a medium having a function of transmitting information, such as a network such as the Internet or a communication network such as a communication network or a telephone line. Further, the program may be for realizing a part of the functions described above. Furthermore, it may be a so-called difference file or difference program that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

DESCRIPTION OF SYMBOLS 1 ... Liquid delivery drive device, 2 ... Syringe, 3 ... Tube, 101 ... Motor, 102 ... Sensor magnet, 103 ... Encoder, 104 ... Drive circuit board, 105 ... 1st mounting plate, 106 ... Shaft, 106A ... long tip, 106B: Short tip, 107: First gear, 108: Second gear, 109: Lead screw, 110: Second mounting plate, 111: Carriage, 112: Guide rod, 113: Control unit, 114: Storage unit, 115: Drive circuit 116: Slit 120: Slider 121: Detection unit 122: Slit 123: Detection hole 131: Interface terminal 204: Pusher 205: Suction opening 206: Tube tip

Claims (9)

Motor,
A drive transmission member for transmitting the rotation of the motor to a load;
A drive circuit for driving the motor;
A sensor that detects a value related to a load torque of the motor as a detected value when the drive transmission member is driven by driving the motor;
A storage unit,
The detected value at the time of initial power-on is stored in the storage unit as a first detected value, and the detected value at the time of power-on after the initial power-on is the first detected value as a second detected value. A control unit that compares the second detection value with the second detection value, and outputs the result of comparing the first detection value and the second detection value;
The control unit
When the initial power is turned on, the first detection value is detected at each predetermined position, and the first detection value is stored in the storage unit at each predetermined position.
When the power is turned on after the initial power-on, the second detection value is detected at each of the predetermined positions, and the second detection value is stored in the storage unit at each of the predetermined positions.
Comparing the first detection value and the second detection value at each of the predetermined positions;
The liquid delivery drive device which outputs a signal indicating an error when a result of comparing the first detection value at the same position and the second detection value increases by a first predetermined amount or more . A fixing part for fixing the load to the liquid delivery drive device;
A detection unit that detects that the load is fixed;
The control unit
When the load is fixed to the fixing portion, the motor is driven to set a value detected by the sensor at each predetermined position as a third detection value.
Comparing the third detection value with the first detection value at each of the predetermined positions;
When the third detection value and the result of comparing the first detection value of the same position is increased a second predetermined amount or more, a signal indicating an error, the liquid delivery drive device according to claim 1 further output . A fixing part for fixing the load to the liquid delivery drive device;
A detection unit that detects that the load is fixed;
The control unit
When the load is fixed to the fixing portion, the motor is driven to set a value detected by the sensor at each predetermined position as a third detection value.
Comparing the third detection value with the second detection value at each of the predetermined positions;
3. The liquid delivery drive device according to claim 2 , further outputting a signal indicating an error when the result of comparing the third detection value at the same position and the second detection value increases by a third predetermined amount or more. . The predetermined position is
Positions driven by a predetermined number of pulse signals input to the drive circuit, or positions moved by one rotation of the drive transmission member, and sections of positions driven by the predetermined number of pulse signals the liquid delivery drive device according to any one of claims 1 to 3 is any one. The control unit
The difference between the third detection value and the second detection value at the same position, the ratio between the third detection value at the same position and the second detection value, and the third detection value and the second detection in the same section A signal indicating an error is further output when any one of the difference between the value and the ratio of the third detection value to the second detection value in the same section increases by a third predetermined amount or more. The liquid delivery drive device according to claim 3 . The control unit
The difference between the third detection value and the first detection value at the same position, the ratio between the third detection value at the same position and the first detection value, and the third detection value and the first detection in the same section A signal indicating an error is further output when any one of a difference with a value and a ratio of the third detection value to the first detection value in the same section increases by a third predetermined amount or more. The liquid delivery drive device according to claim 2 . The sensor is
The liquid delivery drive device according to any one of claims 1 to 6 , which is attached to a substrate to which the control unit is attached. The sensor is
The liquid delivery drive device according to claim 7 attached to the back of the field of said substrate to which said control part is attached. The load is
A syringe pump with pushers,
The control unit
The liquid delivery drive device according to any one of claims 1 to 8 , wherein the motor is driven in a direction in which the solution in the syringe pump is pushed out to drive the pusher in a moving direction of the drive transmission member.

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