JP3203570B2 - Syringe pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a syringe pump for driving a syringe to perform infusion.

[0002]

2. Description of the Related Art A syringe comprises an outer cylinder, a gasket provided in the outer cylinder, and a pusher having one end attached to the gasket. The syringe pump is a device that fixes the outer cylinder of the syringe, moves the pusher at a predetermined speed, slides the gasket in the outer cylinder, and discharges the liquid in the syringe at a predetermined flow rate.

Conventionally, this type of apparatus has required a long time from the start of operation until the liquid is discharged. For example, if the discharge amount per hour is set to several ml or less, it takes several minutes to several tens of minutes after the operation is started until the liquid is discharged. This is because the gasket itself does not move due to the static friction of the gasket even if the presser of the syringe moves immediately after the start of operation, and only the presser side of the gasket is deformed, and the internal volume of the syringe does not change.

For example, when a motor is used to move a pusher, the relationship between the rotation speed of the motor and time is shown in FIG.
(A), and the relationship between the amount of liquid discharged from the syringe and time is shown by a curve A in FIG.

As described above, the conventional syringe pump requires a long time from the start of operation until the liquid is discharged.
For example, when used for medical treatment, there is a drawback that the liquid is not discharged immediately when the syringe is replaced or the flow rate is changed, and the patient's condition is deteriorated.

Conventionally, in a transfusion system using this syringe pump, detection of clogging (clogging) occurring in the middle of an injection line is performed by a pressure sensor using a diaphragm provided in the middle of the injection line, or by pushing a syringe. This is done by mechanically detecting the force pushing the child.
The former, that is, the in-line sensor method using a diaphragm, has the disadvantage that the detection set must be washed and used repeatedly, and the operation is complicated, and the disposable set is expensive. In any case, setting and operation of the instrument are complicated. In the latter case, that is, the mechanical detection method, even if the pressure in the injection line is the same, the force for pressing the pusher differs depending on the type of syringe, so it is difficult to handle a plurality of types of syringes with one syringe pump. .

[0007]

[0008]

[0009]

The conventional syringe pump requires a long time from the start of operation until the liquid is discharged. Further, in a conventional infusion system using a syringe pump, a device for detecting the occurrence of clogging is complicated in operation, expensive, and cannot be used for various syringes .

The present invention has been made to solve these conventional problems, and an object of the present invention is to provide a syringe pump for discharging a liquid at a predetermined flow rate in a short time after the start of operation. An object of the present invention is to provide a syringe pump that can detect the occurrence by a simple operation, is inexpensive, and can accurately detect the occurrence of clogging of various syringes with one unit .

[0011]

According to a first configuration, a syringe comprising an outer cylinder, a gasket provided in the outer cylinder, and a pusher having one end attached to the gasket, is used for fixing the syringe to the outer cylinder. Means, a pressing means for moving the pusher of the syringe having the outer cylinder fixed to the fixing means from the other end side to the one end side and pressing the gasket, and within a predetermined time from the start of pressing. Comprises control means for controlling the pressing means so as to move the presser faster than a predetermined speed and to move the presser at the predetermined speed after the predetermined time has elapsed.

In the second structure, the fixing means and the pressing means in the first structure, force detecting means for outputting a signal corresponding to the force received by the presser of the syringe from the gasket,
Comparing means for comparing the output signal value of the force detecting means with a reference value, and moving the pusher faster than a predetermined speed until the output signal value exceeds the reference value in the comparison by the comparing means after the start of pressing. Control means for controlling the pressing means so as to move the presser at the predetermined speed after the output signal value exceeds the reference value.

In a third configuration, a fixing means for fixing the outer cylinder of the syringe comprising an outer cylinder, a gasket provided in the outer cylinder, and a pusher having one end attached to the gasket, and the fixing means Pressing means for moving the pusher of the syringe with the outer cylinder fixed from the other end side toward the one end side to press the gasket, and a signal corresponding to the force received by the pusher from the gasket. And a reference value or an output signal value of the force detecting means is changed according to friction between the outer cylinder and the gasket and a syringe size, and the reference value is compared with the output signal value. A comparing means for performing processing corresponding to occurrence when the output signal value exceeds the reference value in a comparison result by the comparing means, that is, a processing means ;
Pointer indicating syringe maker and syringe size
A step, wherein the comparing means is provided with a syringe by the indicating means.
Identified by indicating the manufacturer and syringe size
Depending on the syringe size used and the syringe manufacturer specified.
The reference value or the force detection based on the
Changing the output signal value of the output means, its reference value and its
The output signal value is compared with the output signal value .

[0014]

[0015]

According to the first configuration, the pusher moves faster than a predetermined speed within a predetermined time from the start of pressing by the pressing means,
After a lapse of a predetermined time, it moves at a predetermined speed. For this reason, in this syringe pump, the gasket can be changed from the stationary state to the moving state in a short time after the pusher starts being pressed,
The liquid in the syringe starts to be discharged in a short time, and thereafter, the liquid is discharged at a constant flow rate.

According to the second configuration, the pusher moves faster than a predetermined speed from the start of pressing by the pressing means until the output signal value of the force detecting means exceeds the reference value, and at a predetermined speed after the lapse of a predetermined time. Moving. Therefore, similar to the operation of the above configuration,
In this syringe pump, the liquid in the syringe starts to be discharged in a short time from the start of operation, and thereafter, the liquid is discharged at a constant flow rate.

According to the third configuration, the syringe size and
The output signal value or the reference value of the force detection means changes with reference to the friction between the outer cylinder and the gasket, and when the output signal value exceeds the reference value, the processing means performs processing corresponding to the occurrence. Do. For this reason, even if any of a plurality of types of syringes is used, the occurrence of a blockage in the infusion system can be accurately detected, and the blockage can be dealt with. Also,
The outer cylinder and gasket are instructed by the syringe maker.
In other words, the friction between the two is referred to, that is, the occurrence is detected.

[0018]

[0019]

FIG. 1 is a diagram showing the overall configuration of a first embodiment of the present invention. This device includes a control unit 1, a display unit 2, an instruction unit 3,
Syringe size detector 4, drive circuit 5, drive unit 6
And fixing means 7. The control unit 1 includes a central processing unit (hereinafter, CPU) 11, a ROM 12, and a RAM 13. The CPU 11 reads data from the ROM 1 based on data supplied from the instruction unit 3 and the syringe size detector 4.
2 and the RAM 13 to exchange data.
This is a circuit that executes a program stored in the OM 12.

The display 2 displays data provided from the CPU 11.

The instruction unit 3 includes a maker setting switch 31 for setting a maker name, a flow rate setting switch 32 for setting a flow rate per unit time, and a start / stop switch 33 for instructing start / stop of the operation of the apparatus. Instructions from these switches reach the CPU 11.

The syringe size detector 4 detects the diameter of the outer cylinder 82 of the syringe 8 fixed by the fixing means 7. The detection is performed, for example, by detecting the angle of a lever that holds the outer cylinder 82 of the syringe 8.

The drive circuit 5 is a circuit for driving the drive unit 6 under the control of the CPU 11.

The drive unit 6 comprises a motor 61, a pressing member 63 for pressing the pusher 81 of the syringe 8, and a moving mechanism 62 for converting the rotation of the motor 61 into a linear motion of the pressing member 63. The moving mechanism 62 further includes a gear 64 and a rod-shaped member 65.
Consisting of The gear 64 reduces the rotation of the motor 61 and transmits the rotation to the rod-shaped member 65. A screw is provided on the peripheral surface of the rod-shaped member 65, and this screw is screwed with a screw provided on the pressing member 63. The pressing member 63 is prevented from rotating about the longitudinal direction of the rod-shaped member 65 as an axis. When the rod-shaped member 65 rotates, it moves in the longitudinal direction of the rod-shaped member 65. The pressing member 63 presses the gasket 83 in the syringe 81 via the pressing element 81.

The motor 61 is, for example, a pulse motor.
The rotation speed is determined at intervals of the given pulse.

The fixing means 7 is a means for fixing the outer cylinder 82 of the syringe 8 at a predetermined position.

The above-mentioned ROM 12 stores the program shown in the flowchart of FIG. Next, the operation of the apparatus of this embodiment will be described with reference to the flowchart of FIG.

First, the operator turns on the power, fixes the syringe 8 by the fixing means 7, and sets the manufacturer setting switch 3
1 is operated to set the maker of the syringe 8, and the flow rate setting switch 32 is operated to set the flow rate. Accordingly, the CPU 8 reads the set maker and flow rate (steps 101 and 102), and reads the size data from the syringe size detector 4 (step 103). Next, when the operator operates the start / stop switch 33 to instruct the start, the CPU 11 receives the instruction (step 10).
4) The first pulse interval is read from the ROM 12 based on the set manufacturer and the detected size (step 105). Here, the table shown in FIG. 3 is stored in the ROM 12, and the CPU 11 selects and reads one interval from the table. Next, the CPU 11 rotates the motor 61 for 160 ms at a speed corresponding to the selected first pulse interval (step 106).

Next, the CPU 11 sets the manufacturer set as described above,
The second pulse interval is determined based on the detected size and the flow rate set by the flow rate setting switch 32 (step 107). Next, the CPU 11
The motor 61 is rotated at a speed corresponding to the pulse interval (step 108). This rotation is performed until a stop instruction is issued from the start / stop switch 33.

According to this embodiment, 160 m from the start of operation
During the interval s, the motor 61
Rotates, and thereafter, the motor 61 rotates at the pulse of the second pulse interval. The first pulse interval is the second
Is determined to be extremely short as compared with the pulse interval. For example, in the second pulse interval, when the motor 61 is driven by the pulse, the ejection amount of the liquid is 0.1 ml.
/ H, and the first pulse interval is
When the motor 61 is driven by the pulse, the discharge amount of the liquid is 150 ml / h (when driven continuously for a long time).

Therefore, according to this embodiment, when the pusher 81 is started (step 104), it is 160 ms thereafter.
The gasket 83 moves quickly and presses the gasket 83. This 16
During 0 ms, the pusher 81 side of the gasket 83 is pressed and deformed, but the discharge port side of the gasket 83 is not deformed and remains as it is. After a lapse of 160 ms, the gasket 83 bends to the pressing force of the pusher 81 and the whole starts to move. At this time, since the motor 61 is driven by the pulse of the second pulse interval, it moves slowly.

FIG. 4B shows the relationship between the motor rotation speed and time in this embodiment, and the curve B in FIG. 5 shows the relationship between the liquid discharge amount (integrated value) from the syringe 8 and time. . Curve C in FIG. 5 shows an ideal discharge amount,
The curve B is much closer to the ideal than the curve A according to the conventional apparatus.

According to this embodiment, since the stepping motor is used, the rotation speed can be controlled accurately. Further, in this embodiment, the pulse interval is determined in consideration of not only the size of the syringe but also the manufacturer. This is because the coefficient of friction between the outer cylinder and the gasket differs depending on the maker even for the same size. Therefore, according to this embodiment, the discharge amount can be controlled more accurately.

Next, a second embodiment of the present invention will be described. The apparatus according to the present embodiment has both a start-up improvement function, that is, a detection function. FIG. 6 shows the overall configuration of this embodiment. As shown in this figure, the present embodiment has the configuration of the first embodiment, that is, a sensor 21, an amplifier 22 for amplifying the output of the sensor 21, and a CPU for converting the output of the amplifier 22 to a CPU.
11, an attenuator 23 for attenuating and outputting a reference voltage, a reference voltage circuit 25 for generating a reference voltage, and a reference voltage circuit 2
5 is compared with the output of the attenuator 23 and a comparator 24 for outputting the result to the CPU 11 is added. That is, the sensor 21 is connected to the syringe 8
Is a strain gauge for detecting a force applied from the gasket 83 to the moving mechanism 62 via the pusher 81 and the member 63.

FIG. 7 is an enlarged view of the vicinity of one end of the rod-shaped member 65. As shown in this figure, one end of the rod-shaped member 65 is inserted into a tubular member 69 provided in a through hole of the base 66. That is, the sensor 21 is attached to the base 66 by the screw 67. One end of the rod-shaped member 65 is in a state of pressing the sensor 21 via the steel ball 70.

The program shown in the flowchart of FIG. 8 is stored in the ROM 12 of this embodiment.

The operation of this embodiment will be described with reference to FIG. Steps 201 to 205 correspond to the first step shown in FIG.
This is the same as the processing of steps 101 to 105 of the embodiment.

In the next step 206, the CPU 11 rotates the motor 61 at a speed corresponding to the read first pulse interval.

Next, the CPU 11 obtains a first attenuation rate from the set manufacturer and the detected size, and calculates the first attenuation rate.
3 (step 207). For example, in the case of a syringe having a large frictional force between the gasket and the outer cylinder, the damping rate is set large, and in the case of a syringe having a small frictional force between the gasket and the outer cylinder, the damping rate is set small.

Next, the CPU 11 determines whether the output of the attenuator 23 is higher than the reference voltage (step 208). This determination is made based on the output of the comparator 24.

If the CPU 11 determines NO in step 208, it determines whether one second or more has elapsed since the start of the motor drive (step 209). If NO is determined in the step 209, the CPU 11 returns to the step 208. CP
If U11 determines YES in step 209, an alarm sound is generated by a voice generator (not shown),
Is stopped (step 211).

If the CPU 11 determines YES in step 208, the CPU 11 determines a second pulse interval based on the set manufacturer, the detected size, and the flow rate set by the flow rate setting switch 32 (step 21).
0). Next, the CPU 11 rotates the motor 61 at a speed corresponding to the determined second pulse interval (step 212). Also in this case, the relationship between the first pulse interval and the second pulse interval is the same as that in the first embodiment, and the first pulse interval is much shorter.

Next, the CPU 11 obtains a second attenuation rate from the set manufacturer and the detected size, and calculates the second attenuation rate.
3 (step 213). Also in this case, in the case of a syringe having a large frictional force between the gasket and the outer cylinder, the damping rate is set large, and in the case of a syringe having a small frictional force between the gasket and the outer cylinder, the damping rate is set small.

Next, the CPU 11 determines whether the output of the attenuator 23 is higher than the reference voltage based on the output of the comparator 24 (step 214).

If the determination in step 214 is NO, the CPU 11 returns to step 214, and if the determination is YES, the process proceeds to step 215, in which an alarm sound is generated by a sound generator (not shown) and the rotation of the motor 61 is stopped.

In this embodiment, an alarm sound is generated when the high-speed rotation of the motor continues for a predetermined time or more at the time of startup.
The motor was stopped. In this way, it is possible to prevent the liquid from overflowing, and it is possible to avoid a situation in which the apparatus continues to operate with the setting being poor.

FIG. 9A shows the relationship between the force (pressing force) received by the presser from the gasket at the time of starting and time.
FIG. 9B shows the relationship between the amount of liquid discharged from the syringe and time. In each figure, the curve A shows the characteristics of the device of the present embodiment, and the curve B shows the characteristics of the conventional device.

In this embodiment, the CPU 11 changes the output of the amplifier 22 by changing the attenuation rate of the attenuator 23 according to the manufacturer and size of the syringe, and compares this output with the reference voltage. On the other hand, the attenuator 23 is not provided,
The reference voltage may be changed according to the manufacturer and size of the syringe, and the comparator 24 may compare this reference voltage with the output of the amplifier 22. Similarly, the attenuator 23 is not provided, and the amplifier 22 is set according to the manufacturer and size of the syringe.
May be changed, and the output of the amplifier 22 and a constant reference voltage may be compared by the comparator 24.

Next, a third embodiment of the present invention will be described. FIG. 10 shows the overall configuration of this embodiment. As shown in this figure, the present embodiment has a configuration in which a liquid-out sensor 90 is added to the configuration of the first embodiment. The out-of-liquid sensor 90 is provided at a predetermined position with respect to the rod-shaped member 65, and when it detects that the tip of the detecting tongue piece 92 provided integrally with the pressing member 63 has reached the predetermined position, the effect is detected. Signal of C
This is output to the PU 11. The liquid out sensor 90
For example, it is composed of a light source and a photo sensor. In this case, the position detection is performed by detecting whether or not the detection tongue piece 92 blocks the light from the light source. In the present embodiment, the program shown in the flowchart of FIG.

The operation of this embodiment will be described with reference to FIG. Steps 301 to 304 correspond to steps 101 to 104 of the first embodiment shown in FIG.
The processing is the same as that described above. In the next step 305, the CPU 11 reads the ejection amount P when the motor 61 is rotated by one pulse from the set manufacturer and the detected size. Here, the ROM 12 stores a table including a plurality of manufacturers and sizes and discharge amounts corresponding to one pulse corresponding thereto, and the CPU 11 selects one discharge amount from the tables.

Next, the CPU 11 determines a pulse interval based on the manufacturer and the size (step 306). Next, the CPU 11 rotates the motor 61 at a speed corresponding to the determined pulse interval (step 307).

Next, the CPU 11 determines whether the liquid-out sensor is on or off (step 308). That is, the CPU 11 determines whether the pressing member 65 or the pressing member 81 has reached a predetermined position (ON state) or not (OFF state).
This determination is made until the ON state is reached, and when it is determined that the ON state has been reached, the CPU 11 reads the out-of-liquid constant K from the manufacturer and size (step 309). Where ROM
12 stores a table including a plurality of types of manufacturers and sizes and a constant K corresponding to them, as shown in FIG. 12, and the CPU 11 selects one constant K from these tables. Here, K is the amount (remaining amount) of the liquid in the syringe 8 when the liquid-out sensor 90 is turned on.

Next, when the motor 61 rotates one pulse, the CPU 11 determines the remaining amount of liquid in the syringe at that time.
The calculation is performed based on the ejection amount P obtained in step 305 and the constant K read in step 309 (step 310).
That CPU11 calculates _{K n = K n-1 -P} . Where K _n is the remaining amount when the solution break sensor 90 is the n-th pulse from when one was given to the motor 61,
K _o = K (the constant selected above).

Next, the CPU 11 determines whether K _n ≦ 0.2 (step 311), and if it determines YES, stops the motor 61 (step 312) and outputs an alarm sound of a liquid shortage alarm (not shown). Is generated, and the fact is displayed on the display 2 (step 313). CPU11
If NO is determined in step 311, it is determined whether K _n ≦ 1.0 (step 314). If NO is determined, the process returns to step 310. The CPU 11 determines in step 314 that Y
If it is determined to be ES, the process proceeds to step 315, in which an alarm sound for a notice of running out of liquid is generated from a sound generator (not shown), and the fact is displayed on the display 2. Numerical value 0.2 in step 311 and numerical value 1.0 in step 314
Is an example. For example, the numerical value in step 311 may be 0 or another value slightly before becoming 0.

FIG. 1 shows the relationship between the processing from the time the sensor is turned on until the liquid runs out and the remaining amount of the liquid.
3 is shown.

[0056]

According to the first and second configurations of the present invention, the liquid can be discharged in a short time after the start of the operation.

According to the third configuration of the present invention, since the friction between the outer cylinder and the gasket is referred to, it is possible to accurately detect the occurrence of the clogging, and to perform the processing for it. That is, the setting and operation of the device for detecting occurrence are simple.
Also, by instructing the syringe manufacturer,
The friction between the outer cylinder and the gasket
Or the output signal value of the force detection means changes,
The setup and operation of the device for raw detection is even easier.
You.

[0058]

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the first embodiment of the present invention.

FIG. 3 is a conceptual diagram of a part of data stored in a ROM according to the first embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between the rotation speed of a motor and time in the apparatus according to the first embodiment of the present invention and the conventional apparatus.

FIG. 5 is a diagram showing a relationship between a discharge amount and time in the apparatus according to the first embodiment of the present invention and a conventional apparatus.

FIG. 6 is a diagram showing an overall configuration of a second embodiment of the present invention.

FIG. 7 is an enlarged view of a part of the second embodiment of the present invention.

FIG. 8 is a diagram for explaining the operation of the second embodiment of the present invention.

FIG. 9 is a diagram for explaining the operation of the second embodiment of the present invention.

FIG. 10 is a diagram showing the overall configuration of a third embodiment of the present invention.

FIG. 11 is a diagram for explaining the operation of the third embodiment of the present invention.

FIG. 12 is a conceptual diagram showing a part of data stored in a ROM according to a third embodiment of the present invention.

FIG. 13 is a diagram for explaining the operation of the third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Control part 2 Indicator 3 Indicator part 4 Syringe size detector 5 Drive circuit 6 Drive unit 7 Fixing means 21 That is, sensor 24 Comparator 25 Reference voltage circuit 90 Liquid out sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-228852 (JP, A) JP-A-63-177864 (JP, A) JP-A-2-121672 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A61M 5/145

Claims (3)

(57) [Claims] A fixing means for fixing the outer cylinder of a syringe comprising an outer cylinder, a gasket provided in the outer cylinder, and a pusher having one end attached to the gasket; Pressing means for moving the presser of the fixed syringe from the other end side to the one end side to press the gasket; and for moving the presser faster than a predetermined speed for a predetermined time from the start of pressing. And a control means for controlling the pressing means so as to move the pusher at the predetermined speed after the predetermined time has elapsed. 2. A fixing means for fixing the outer cylinder of a syringe comprising an outer cylinder, a gasket provided in the outer cylinder, and a pusher having one end attached to the gasket; Pressing means for moving the pusher of the syringe with the fixed in the direction from the other end to the one end to press the gasket, and a force for outputting a signal corresponding to the force received by the pusher from the gasket. Detecting means;
Comparing means for comparing the output signal value of the force detecting means with a reference value, and moving the pusher faster than a predetermined speed until the output signal value exceeds the reference value in the comparison by the comparing means after the start of pressing. And a control means for controlling the pressing means so as to move the pusher at the predetermined speed after the output signal value exceeds the reference value. 3. A fixing means for fixing the outer cylinder of a syringe comprising an outer cylinder, a gasket provided in the outer cylinder, and a pusher having one end attached to the gasket; Pressing means for moving the pusher of the syringe with the fixed in the direction from the other end to the one end to press the gasket, and a force for outputting a signal corresponding to the force received by the pusher from the gasket. Detecting means;
A comparison unit that changes a reference value or an output signal value of the force detection unit according to friction between the outer cylinder and the gasket and a syringe size, and compares the reference value with the output signal value; When the output signal value exceeds the reference value as a result of the comparison, ie, processing corresponding to the occurrence, that is, a processing means ;
And instructing means for instructing a syringe size, wherein the comparing means communicates with the syringe maker by the instructing means.
The syringe specified by specifying the syringe size
The friction according to the syringe manufacturer specified as the syringe size
Based on the friction, before the reference value or the force detection means
The output signal value is changed, its reference value and its output signal value are changed.
A syringe pump characterized by comparing with: