JPH0399231A - Backlash correction of syringe pump apparatus - Google Patents

Abstract

PURPOSE:To make it possible to suck chemical accurately by moving a plunger based on a reference command value, moving the plunger furthermore manually, obtaining a correcting value, and correcting the command value when the chemical is sucked. CONSTITUTION:A plunger 2a is moved into the sucking direction based on a reference command value. At this time, the plunger 2a is stopped before a scale position Ms corresponding to the reference command value. Therefore, the plunger 2a is manually moved to the scale Ms. The reference command value is corrected with the amount of movement. Thus, the backlash generated in a syringe pump apparatus is offset, and chemical can be sucked accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a backlash correction method for a syringe pump device that administers a drug solution to test animals in animal experiments.

[Prior art and issues]

Equipped with a syringe having a plunger whose forward and backward movement is controlled by a drive unit, the syringe inhales a medicinal solution from a medicinal solution container, and
Syringe pump devices for conducting animal experiments by administering inhaled medicinal solutions to test animals are known.

By the way, in the syringe pump device, as shown in FIG. 4, a pack rush R occurs when the drug solution is inhaled into the syringe 46, and the actual suction amount Hc becomes smaller than the original suction amount Hs based on the command value.

Backlash R usually occurs due to mechanical mechanisms, but when disposable syringes are used, backlash R may also occur due to deformation of elastic parts such as gaskets, and may also be caused by the viscosity of the drug solution, the inhalation speed, Since it varies depending on the shape of the syringe, etc., it cannot be dealt with by uniform correction.

Conventionally, when correcting backlash, for example,
When inhaling a medicinal solution, a larger amount than the intended inhalation amount was inhaled, and then the scale was returned to the original position. However, this method requires repeating the same operation every time the drug solution is inhaled, which makes the control system extremely complicated.
As shown in the figure, a three-way valve 5 opens a check valve 53 during inhalation into a syringe 51 to inhale a drug solution 54, and opens a check valve 55 during administration to send it to the translozone 56 side.
If method 2 is used, the returned chemical solution will be wasted, which is not preferable.

An object of the present invention is to provide a backlash correction method for a syringe pump device that solves the problems existing in the prior art.

[Means to solve the problem]

In the backlash correction method according to the present invention, in the syringe pump device 1, the plunger 2a is moved in the suction direction from the zero scale position MO by the drive unit 3 based on the reference command value S to inhale the medicinal solution, and then the manual operation is performed. to move the plunger 2a to the scale position Ms corresponding to the reference command value S, read and memorize the manual movement value L of the plunger 2a, and set the command value Sn based on the movement value when inhaling the medicinal solution from now on. It is characterized by correction, for example, by adding a movement value L to the command value Sn.

[For production]

According to the backlash correction method for a syringe pump device according to the present invention, based on the reference command value S, the plunger 2a
is moved in the suction direction by the drive unit 3. In this case, due to the presence of backlash, the plunger 2a stops before the scale position Ms corresponding to the reference command value S. Therefore, by manual operation, the plunger 2a is moved to the scale position M.
If the plunger 2a is moved to s, the movement value of the plunger 2a will be the same value as the magnitude of the bubble crash, so the movement value L should be memorized and added to the command value Sn when inhaling the drug solution from now on. If so, the puck rush is canceled.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

First, in order to clarify the present invention, the overall schematic configuration of the drug solution administration system G will be described with reference to FIG. 2.

25 is an electronic balance having a measuring pan 25a, and is connected to the syringe pump device l. The syringe pump device l has a built-in computer function, and the top panel has a keyboard 2.
6. In addition to arranging the display 27, the driver 3 (
The syringe 2 is equipped with a plunger 2a whose forward and backward movement is controlled by a cylinder (see FIG. 3).

A switch 29 is connected to the inlet/outlet 2b of the syringe 2. The switching device 29 is a three-way valve with a built-in check valve as shown in FIG.
Alternatively, a three-way stopcock or the like that can be switched by a cock can be used, and has the function of selectively connecting the drug solution container 30 containing the drug solution or the intravenous injection needle 31 (transfusion needle 32) to the entrance/exit 2b.

Further, a printer 28 for printing out data is connected to the syringe pump device l if necessary.

Next, the syringe 2 and its surrounding structure will be explained with reference to FIG. 2.

The syringe 2 includes a syringe outer cylinder 2c and this syringe outer cylinder 2c.
The plunger 2a is inserted from the rear of the plunger 2a. The syringe outer cylinder 2c has a scale 2p displayed on its circumference in the axial direction,
The rear end is provided with an integrally formed flange 33, and the tip is provided with the entrance/exit 2b. Then, the flange 33 is fitted into a groove 34 provided on the main body side of the syringe pump device l and fixed. Further, the switching device 29 is connected to the entrance/exit 2b.

On the other hand, the plunger 2a has a rubber gasket 35 at its tip.
and integrally includes a flange 36 connectable to the drive unit 3 at the rear end.

On the other hand, the drive unit 3 includes a screw 37 and a nut 38 that is screwed onto the screw 37. This nut 38 has an integral connecting part 38a in which a groove part 38b is formed, and the flange 36 of the plunger 2a is fitted and connected to this groove part 38b. Also, a timing pulley 39 is provided at the end of the screw 37.
Rotation is transmitted to this timing pulley 39 via a timing belt 43 from a timing pulley 42 attached to an output shaft 4l of a stepping motor 40, for example. Therefore, the rotation of the screw 37 causes the nut 38,
Furthermore, the forward and backward movement of the integrated plunger 2a can be controlled. Note that the output shaft 4l of the stepping motor 40 is provided with a manual operation handle 44 that can be rotated manually.
It is equipped with a rotary encoder 45 that detects the rotational position.

Next, the packlash correction method according to the present invention will be explained with reference to the flowchart of FIG.

First, the plunger 2a is set to the most pushed position relative to the syringe outer cylinder 2c', that is, the zero scale position Mo. Next, by applying the reference command value S, the drive unit 3 is actuated to move the plunger 2a in the suction direction (step IL12).

Note that the control based on the reference command value S can be performed, for example, by controlling the rotation angle of the stepping motor 40. Then, upon completion of the control based on the reference command value S, the drive unit 3
The operation of is stopped (steps 13 and 14). Because the plunger 2a in this state has not reached the scale position MS corresponding to the reference command value S due to backlash,
The plunger 2a is moved in the suction direction by manual operation and adjusted to the scale position Ms (steps 15, 16, 17).

The movement value L of the plunger 2a due to this manual operation is read by the rotary encoder 42 attached to the stepping motor 40, for example (step tS), and is stored in the memory provided in the syringe pump device l (step 19).
).

Therefore, when inhaling the medicinal solution from now on, the movement value L can be added to the original command value Sn to control the inhalation of the medicinal solution (
Step 20). This cancels pack rush and allows accurate inhalation at all times.

The above correction procedure can be executed by software based on a control program.

On the other hand, the overall function of the drug solution administration system G is as follows. First, the weight data of the test animal M measured by the electronic balance unit 25 is stored in the syringe pump device 1, and the required amount of drug solution is calculated based on the weight data. Then, the calculated amount of chemical liquid is set as the command value Sn, and the movement value L is further added to perform correction, and the driving section 3 is controlled to control the plunger 2a.
move. Thereby, the drug solution can be inhaled from the drug solution container and the drug solution can be administered to the test animal M.

Note that the present invention is not limited to such embodiments. For example, the stepping motor can be replaced with another motor, and the rotary encoder can be replaced with any other position sensor or the like. Other changes may be made in the detailed structure and the like without departing from the gist of the present invention.

〔Effect of the invention〕

As described above, the backlash correction method for a syringe pump device according to the present invention moves the plunger according to the reference command value, further moves the plunger by manual operation, and uses the movement value by this manual operation to adjust the command value at the time of drug inhalation. Since the correction is made, it is possible to cancel the backlash that occurs in this type of syringe pump device, and it is possible to accurately inhale the drug solution, which has the remarkable effect of being extremely easy to inhale.

[Brief explanation of drawings]

Fig. 1.2 A flowchart showing a backlash correction method for a syringe pump device according to the present invention. Fig. 2. An overall configuration diagram of a liquid drug administration system including the syringe pump device. Fig. 3.2 A syringe in the syringe pump device and its FIG. 4: An explanatory diagram of backlash that occurs in a syringe pump device. FIG. 5: A schematic diagram of the syringe and its surroundings showing problems in the prior art. In the drawings, 1: Syringe pump device 2: Syringe 2a: Plunger 3: Drive unit Fig. 2 Fig. 3

Claims (1)

[Scope of Claims] [1] In a syringe pump device comprising a syringe having a plunger whose forward and backward movement is controlled by a drive unit, the drive unit moves the plunger from a zero scale position in the suction direction based on a reference command value. After that, manually move the plunger to the scale position corresponding to the standard command value, read and store the manually operated plunger movement value, and use the movement value as the basis for subsequent drug inhalation. A backlash correction method for a syringe pump device, characterized in that a command value is corrected based on a command value. [2] The backlash correction method for a syringe pump device according to claim 1, wherein the correction is performed by adding a movement value to the command value.