JPH0672790B2 - Backlash correction method for syringe pump device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a backlash correction method for a syringe pump device that administers a drug solution to a test animal in an animal experiment.

[Prior art and problems]

A syringe having a plunger that is controlled to move back and forth by a drive unit is provided, and while sucking the chemical liquid from the chemical liquid container,
A syringe pump device for administering an inhaled drug solution to a test animal and conducting an animal experiment is known.

By the way, in the syringe pump device, as shown in FIG. 4, a backlash R occurs when the liquid medicine is sucked into the syringe 46, and the actual suction amount Hc is the original suction amount Hs based on the command value.
Less than. The backlash R usually occurs due to a mechanical mechanism, but when a disposable syringe is used, the backlash R also includes that due to deformation of an elastic part such as a gasket, and further, the viscosity of the liquid medicine, the inhalation speed, Since it depends on the form of the syringe, etc., uniform correction cannot be applied.

Conventionally, when correcting backlash, for example,
At the time of inhaling a chemical solution, a larger amount than the intended inhalation amount was inhaled, and then the original scale position was returned. However, in this method, the same operation must be repeated each time a chemical solution is inhaled, so that the control form becomes extremely complicated, and as shown in FIG.
Open 53 and inhale the drug solution 54, and also check valve at the time of administration.
When the three-way valve 52 that opens 55 and sends it to the oral sonde 56 side is used, the returned drug solution is wasted, which is not preferable.

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

[Means for Solving the Problems]

In the backlash correction method according to the present invention, in the syringe pump device 1, the drive unit 3 moves the plunger 2a from the zero scale position Mo in the suction direction based on the reference command value S to suck the chemical liquid, and then the manual operation is performed. By plunger 2a
Is moved to the scale position Ms corresponding to the reference command value S, the movement value L of the plunger 2a by manual operation is read and stored, and the command value Sn is corrected based on the movement value L at the time of inhaling the chemical solution thereafter, for example, The feature is that the movement value L is added to the command value Sn for correction.

[Action]

According to the backlash correction method for the syringe pump device of the present invention, the plunger 2a is moved in the suction direction by the drive unit 3 based on the reference command value S. In this case, due to the presence of backlash, the plunger 2a has the reference command value S
Stop before the scale position Ms corresponding to. Therefore, if the plunger 2a is moved to the graduation position Ms by a manual operation, the movement value L of the plunger 2a becomes the same value as the magnitude of the backlash, so that the movement value L is stored and the liquid medicine is inhaled thereafter. The backlash is canceled by adding the movement value L to the command value Sn.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

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

Reference numeral 25 denotes an electronic balance section having a weighing pan 25a, which is connected to the syringe pump device 1. The syringe pump device 1 has a built-in computer function, has a keyboard 26 and a display 27 on the upper panel, and is equipped with a syringe 2 in which a plunger 2a is controlled to move back and forth by a drive unit 3 (see FIG. 3).

A switch 29 is connected to the entrance / exit 2b of the syringe 2. Switch
29 is a three-way valve with a built-in check valve shown in FIG. 5, or a three-way stopcock that can be switched by a cock, and the drug solution container 30 containing the drug solution or the intravenous injection needle 31 (oral sonde 32) can be taken in and out. It has a function of selectively connecting to 2b.

A printer 28 for printing out data is connected to the syringe pump device 1 if necessary.

Next, the syringe 2 and its peripheral structure will be described with reference to FIG.

The syringe 2 comprises a syringe outer cylinder 2c and a plunger 2a inserted from the rear part of the syringe outer cylinder 2c. The syringe outer cylinder 2c has a scale 2p displayed in the axial direction of the peripheral surface, and integrally has a flange 33 integrally formed at the rear end and the inlet / outlet 2b at the tip. Then, the flange 33 is fitted and fixed in the groove portion 34 provided on the main body side of the syringe pump device 1. Further, the switch 29 is coupled to the entrance / exit 2b.

On the other hand, the plunger 2a is provided with a rubber gasket 35 at the front end and a flange that can be connected to the drive unit 3 side at the rear end.
Equipped with 36 in one.

On the other hand, the drive unit 3 includes a screw 37 and a nut 38 that is screwed into the screw 37. The nut 38 integrally has a connecting portion 38a having a groove 38b formed therein, and the flange 36 of the plunger 2a is fitted and connected to the groove 38b. A timing pulley 39 is attached to the end of the screw 37, and rotation is transmitted to the timing pulley 39 from a timing pulley 42 attached to an output shaft 41 of a stepping motor 40 via a timing belt 43. Therefore, by rotating the screw 37, the nut 38 and the integral plunger 2a can be moved back and forth. The output shaft 41 of the stepping motor 40 is coupled with a manual operation handle 44 that can be rotated by a manual operation, and a rotary encoder 45 that detects a rotational position is provided.

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

First, the plunger 2a is set to the most pushed position with respect to the syringe outer cylinder 2c, that is, the zero scale position Mo. Then
By applying the reference command value S, the drive unit 3 is operated and the plunger 2a is moved in the suction direction (step 1
1, 12). The control based on the reference command value S can be performed by controlling the rotation angle of the stepping motor 40, for example. Then, when the control based on the reference command value S is completed, the operation of the drive unit 3 is stopped (steps 13 and 14). Since 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 sent 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 by this manual operation is read by, for example, the rotary encoder 42 attached to the stepping motor 40 (step 18) and stored in the memory provided in the syringe pump device 1 (step 19).

Therefore, at the time of inhaling the chemical liquid thereafter, the movement value L can be added to the original command value Sn to perform the chemical liquid suction control (step 20). As a result, backlash is canceled, and accurate inhalation can always be performed.

The above correction procedure can be executed by software by the control program.

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

The present invention is not limited to such an embodiment. For example, the stepping motor can be replaced with another motor, and the rotary encoder can be replaced with another arbitrary position sensor or the like. In addition, the detailed configuration and the like can be arbitrarily changed without departing from the scope of the present invention.

〔The invention's effect〕

As described above, the backlash correction method for the syringe pump device according to the present invention moves the plunger according to the reference command value, and further moves the plunger by manual operation, and the command value at the time of inhaling the chemical liquid is determined by the movement value due to this manual operation. Since the correction is performed, the backlash that occurs in this type of syringe pump device can be canceled, and the medicinal solution can be accurately inhaled, and there is a remarkable effect that it can be performed extremely easily.

[Brief description of drawings]

1 is a flowchart showing a backlash correction method for a syringe pump device according to the present invention, FIG. 2 is an overall configuration diagram of a drug solution administration system including the syringe pump device, and FIG. 3 is a syringe in the syringe pump device and the same. FIG. 4 is a partially longitudinal front view showing a peripheral mechanism, FIG. 4: an explanatory view of backlash that occurs in a syringe pump device, and FIG. 5: a schematic view of a syringe periphery showing problems of the conventional technology. In the drawing, 1: syringe pump device, 2: syringe 2a: plunger, 3: drive unit

Claims (2)

[Claims] 1. A syringe pump device comprising a syringe having a plunger whose forward and backward movement is controlled by a drive unit, wherein the drive unit moves the plunger in a suction direction from a zero scale position based on a reference command value to inhale a chemical solution. Then
Thereafter, the plunger is manually moved to the scale position corresponding to the reference command value, and the plunger movement value by the manual operation is read and stored, and the command value is corrected based on the movement value at the time of inhaling the chemical liquid thereafter. A method for correcting backlash in a syringe pump device, comprising: 2. The backlash correction method for a syringe pump device according to claim 1, wherein the movement value is added to the command value for correction.