JP6764319B2 - Drug injection device - Google Patents

Description

The present disclosure relates to, for example, a drug infusion device that injects a drug such as insulin or growth hormone.

The configuration of the conventional drug injection device of this type is as follows.

That is, the injection needle insertion portion is a drug syringe mounting portion for mounting a drug syringe having an injection needle insertion portion on the tip side and a gasket inside the rear end, and the gasket in the drug syringe mounted on the drug syringe mounting portion. It had a configuration including a piston pushed to the side and a piston moving mechanism for moving the piston (for example, Patent Document 1 below).

Then, when the piston moves and pushes the gasket in the drug syringe toward the injection needle insertion part, the drug in the drug syringe is discharged through the injection needle in the injection needle insertion part, whereby the drug is administered to the patient. ..

Japanese Patent Publication No. 2004-516107

The problem in the above-mentioned conventional example is that there is a possibility that appropriate drug administration cannot be performed.

That is, in the configuration of the above-mentioned conventional example, the piston pushes the gasket in the drug syringe toward the injection needle insertion portion side to discharge the drug.

At this time, a so-called stick-slip phenomenon may occur in which the contact surface between the gasket and the inner surface of the drug syringe repeats stick (adhesion) and slip (slip) due to the frictional force of the contact surface. When this stick-slip phenomenon occurs, the gasket moves while repeating rapid movement and rest, and a state in which rapid discharge and non-discharge of the drug are repeated. Therefore, it is difficult to administer the intended amount of the drug, and as a result, there is a risk that an appropriate drug administration cannot be performed.

Therefore, the present disclosure provides a drug injection device capable of performing appropriate drug administration.

The drug injection device of the present disclosure includes a drug syringe mounting portion for mounting a drug syringe having an injection needle insertion portion on the tip side and a gasket on the inside of the rear end, and the gasket in the drug syringe mounted on the drug syringe mounting portion. A piston that pushes the syringe into the injection needle insertion portion, a piston moving mechanism that moves the piston, a piston rotating mechanism that is connected to the piston and rotates the piston around the axis of the drug syringe, and the gasket of the piston. It is provided on the side and includes a rotational force transmission unit that transmits the rotational force to the gasket.

According to the drug injection device of the present disclosure, when the piston rotation mechanism rotates the piston around the axis of the drug syringe, this rotation is transmitted to the gasket via the rotational force transmission unit, and the gasket can be rotated about the axis. it can. That is, by rotating the gasket, the contact surface between the gasket and the inner surface of the drug syringe can be made free of sticks (adhesion).

Then, when the rotating gasket is pushed toward the injection needle insertion portion, the stick-slip phenomenon does not occur because there is no stick (adhesion).

Therefore, since the gasket moves at a constant speed, the drug is stably discharged, and the intended amount of the drug can be administered. As a result, appropriate drug administration can be performed.

It is a perspective view which shows the drug injection device which concerns on one Embodiment of this disclosure. It is a perspective view of the drug injection device shown in FIG. It is sectional drawing of the drug injection apparatus shown in FIG. It is a control block diagram which shows the electrical connection of the drug injection device shown in FIG. It is a figure explaining the occurrence state of a problem. It is an enlarged perspective view of the main part in the drug injection device shown in FIG. It is sectional drawing of the main part in the drug injection apparatus shown in FIG. It is sectional drawing of the main part in the drug injection apparatus shown in FIG. It is an operation flowchart of the drug injection device shown in FIG.

Hereinafter, one embodiment of the present disclosure will be described with reference to the accompanying drawings.

(Embodiment 1)
1 and 2 show the drug injection device 1 of the present embodiment, and the drug injection device 1 includes a main body case 2 having a substantially rectangular parallelepiped shape. An injection needle mounting portion 3 is provided on the front end side (lower side in FIG. 1) of the main body case 2, and the injection needle 4 of FIG. 2 is mounted on the injection needle mounting portion 3.

An injection button 5 for injecting an injection is provided on the rear end side (upper side in FIG. 1) of the main body case 2, and on the surface of the main body case 2, a display unit 6 for guiding an injection display and a drug injection device 1 are provided. A power button 7 for turning on the power is provided.

A drug syringe mounting portion 8 is provided on the front end side of the main body case so as to be openable and closable as shown in FIGS. 1 and 2. When the drug syringe 9 is inserted into the drug syringe mounting portion 8 as shown in FIG. 1 and the drug syringe mounting portion 8 is closed as shown in FIG. 2, the drug syringe 9 is mounted at a predetermined position of the drug syringe mounting portion 8. , Subsequent drug administration operation becomes possible.

FIG. 3 is a cross-sectional view showing the inside of the drug injection device 1, and the drug syringe 9 is attached to the tip end side (left side in FIG. 3) of the main body case 2. The drug syringe 9 has a cylindrical shape and has an injection needle insertion portion 10 made of rubber (an example of an elastic body) on the tip side and a gasket 11 made of rubber (an example of an elastic body) on the inside of the rear end. Inside the drug syringe 9, the drug 12 is sealed in a state where the injection needle insertion portion 10 and the gasket 11 are plugged. For example, four doses of the drug 12 are sealed in the drug syringe 9.

On the rear side of the gasket 11 of the attached drug syringe 9, a cylindrical elongated piston 13 is used in the drug syringe 9 with its axis (central axis) aligned with the axis (central axis) of the drug syringe 9. The inside is slidably provided. Therefore, when the piston 13 moves toward the front gasket 11 side (direction A in FIG. 3), the tip of the piston 13 comes into contact with the front gasket 11 and pushes the gasket 11 in the drug syringe 9 toward the injection needle insertion portion 10. I will go.

A moving motor 14 for moving the piston 13 is provided in the main body case 2, and a screw 15 is connected to the moving motor 14. The screw 15 is combined with a nut 16 and the nut 16 is fixed to a rectangular moving base 17. A rotation motor (an example of a piston rotation mechanism) 18 for rotating the piston 13 around the axis of the drug syringe 9 is provided on the moving table 17, and the piston 13 is connected to the rotation motor 18. That is, the moving table 17 holds the rotary motor 18 and the piston 13. Further, both ends of the moving table 17 are slidably supported by two support shafts 19 in the front-rear direction (direction along the axis of the drug syringe 9).

With this configuration, when the moving motor 14 is rotated, the moving table 17 moves forward (in the direction of arrow A in FIG. 3) via the screw 15 and the nut 16. The piston 13 held by the moving table 17 moves forward along the axis of the drug syringe 9 together with the rotation motor 18, and pushes the gasket 11 in the drug syringe 9 toward the injection needle insertion portion 10. .. That is, the moving motor 14, the screw 15, the nut 16, and the moving base 17 form a piston moving mechanism for moving the piston 13.

The front side of the piston 13 is held by the piston holding portion (rotary bearing) 20. The piston holding portion 20 slidably holds the piston 13 along the axis of the drug syringe 9 and rotatably holds the piston 13 around the axis of the drug syringe 9. Therefore, the piston 13 can stably slide (move) and rotate.

Further, a battery 21 is provided in the main body case 2, and electricity is supplied to each part by the battery 21.

FIG. 4 shows the electrical connection state of each part.

A mobile motor 14, a rotary motor 18, a battery 21, a power button 7, an injection button 5, and a display unit 6 are electrically connected to the control unit 22. Further, the control unit 22 stores a storage of a drug syringe mounting detection unit 23 for detecting that the drug syringe 9 is mounted on the drug syringe mounting unit 8 and a control program for the control unit 22 to perform various controls. The unit 24 is connected.

Although the battery 21 is connected only to the control unit 22, the battery 21 is configured to supply power to each unit shown in FIG. Further, the control unit 22 and the storage unit 24 are each composed of an electric circuit and are provided on a control board (not shown) in the main body case 2.

Then, when the user presses the injection button 5 of FIG. 1, the control unit 22 starts the injection operation and rotates the moving motor 14. Then, as shown in FIG. 5, when the piston 13 moves toward the front gasket 11 side (direction A in FIG. 5), the tip of the piston 13 comes into contact with the front gasket 11 and the gasket 11 in the drug syringe 9 is injected. Push it toward the insertion part 10.

At this time, on the contact surface between the gasket 11 and the inner surface of the drug syringe 9, a so-called stick-slip phenomenon may occur in which stick (adhesion) and slip (slip) are repeated due to the frictional force of the contact surface.

Since the stick-slip phenomenon is a well-known phenomenon, it will be briefly described with reference to FIG.

For example, when four doses of the drug 12 are sealed in the drug syringe 9, in the first injection operation, the piston 13 pushes the gasket 11 to the position P1 where the first injection ends, and the drug 12 is pushed by only one quarter. Discharge.

Specifically, after the piston 13 is moved in the direction of the gasket 11 (a in FIG. 5) and brought into contact with the rear end surface of the gasket 11 (b in FIG. 5), the gasket 11 is inserted into the injection needle insertion portion 10 side by the piston 13. Push it into. At this time, since the contact surface between the gasket 11 and the inner surface of the drug syringe is in a stick (adhered) state due to frictional force, the gasket 11 made of rubber is pushed by the piston 13 and elastically deforms, but does not move immediately (FIG. 5). c). When the piston 13 is further pushed in, the gasket 11 and the inner surface of the drug syringe are peeled off, the gasket 11 suddenly slips forward, and the contact surface between the gasket 11 and the inner surface of the drug syringe sticks (attaches) again (FIG. 5 d).

When such a stick-slip phenomenon occurs, the gasket 11 moves to a predetermined injection end position P1 while repeating rapid movement and rest.

That is, as shown in FIGS. 5c to 5d, the tip surface of the gasket 11 repeats rapid movement and rest, so that rapid discharge and non-discharge of the drug 12 are repeated. In this state, the intended amount of the drug is adjusted. It becomes difficult to administer. For example, even if the piston 13 moves to the predetermined injection end position, when the stick is generated, the tip surface of the gasket 11 does not reach the predetermined injection end position P1, that is, the intended drug. The amount cannot be administered. As a result, there was a concern that appropriate drug administration could not be performed.

Therefore, in the present embodiment, as shown in FIG. 3, a rotation motor 18 (an example of a piston rotation mechanism) for rotating the piston 13 around the axis of the drug syringe 9 is connected to the rear side of the piston 13. It is provided. Therefore, when the rotation motor 18 is rotated, the piston 13 rotates around the axis of the drug syringe 9.

Then, in order to transmit this rotational force to the gasket 11, a blade 25 (an example of the rotational force transmitting portion) is provided on the gasket 11 side of the piston 13 as a rotational force transmitting portion for transmitting the rotational force to the gasket 11. A needle may be provided instead of the blade 25. Further, the gasket 11 is provided with a concave portion, and a convex portion corresponding to the concave portion may be provided on the gasket 11 side of the piston 13.

FIG. 6 is an enlarged perspective view of the blade 25 portion. At the end of the piston 13 on the gasket 11 side, a pushing surface 26 for pushing the gasket 11 is provided, and two pieces (plural pieces) projecting toward the gasket 11. Blade (an example of a convex portion) 25 is provided. The number of blades 25 may be one, but if a plurality of blades 25 are provided, the rotational force can be transmitted more reliably. The two blades 25 are provided so as to be axially symmetric with respect to the central axis (rotational axis) of the piston 13 with its cutting edge facing the gasket 11. The blade 25 projects toward the gasket 11 from the pushing surface 26.

As shown in FIG. 7, the blade 25 is inserted into and engaged with the gasket 11 made of rubber to transmit the rotational force of the piston 13 to the gasket 11, so that the gasket 11 can be rotated about the axis. it can.

That is, when the drug is administered, the gasket 11 is rotated around the axis so that there is no stick (adhesion) on the contact surface between the gasket 11 and the inner surface of the drug syringe 9.

Then, when the rotating gasket 11 is pushed toward the injection needle insertion portion 10, the stick-slip phenomenon does not occur because there is no stick (adhesion).

The operation at this time will be further described with reference to FIGS. 4 and 7 to 9.

7 and 8 are diagrams for explaining the operation of drug administration, and FIG. 9 is a control flowchart of the control unit 22.

When the power button 7 of FIG. 1 is turned on by the user, the control unit 22 is activated (S1 of FIG. 9).

The control unit 22 uses the drug syringe mounting detection unit 23 of FIG. 4 to detect whether or not a new drug syringe 9 is mounted on the drug syringe mounting unit 8. When the drug syringe mounting detection unit 23 detects that a new drug syringe 9 has been mounted, the control unit 22 rotates the moving motor 14 and directs the piston 13 from the state of FIG. 3 toward the gasket 11 (FIG. 3). (A direction of 3) Move.

Then, as shown in FIG. 7, the blade 25 of the piston 13 is inserted into the gasket 11 made of rubber, and the piston 13 and the gasket 11 are integrally connected. Since this connection is performed in a state where the injection needle 4 is not attached to the drug syringe 9, the drug 12 filled in the drug syringe 9 is not discharged. That is, since the drug 12 exists in the non-discharged state, the gasket 11 does not move, and the blade 25 can be firmly inserted into the gasket 11. In this way, the piston 13 is moved to the initial position where the gasket 11 is pushed (S2 in FIG. 9).

After that, when the injection needle 4 is attached to the injection needle mounting portion 3 of the main body case 2, the needle main body 27 of the injection needle 4 is inserted into the injection needle insertion portion 10 of the drug syringe 9 as shown in FIG. Will be done.

In this state, the user holds the main body case 2 and pierces the needle main body 27 of the injection needle 4 into the injection position of the user. Then, when the user presses the injection button 5 in FIG. 1, the control unit 22 starts the injection operation (S3 in FIG. 9).

First, the control unit 22 rotates the rotation motor 18 to rotate the piston 13 (direction B in FIG. 7). Then, since the piston 13 and the gasket 11 are integrally connected by the blade 25, the rotation of the piston 13 is transmitted to the gasket 11 via the blade 25, and the gasket 11 is moved around the axis of the piston 13 in the piston 13. It rotates (S4 in FIG. 9).

By rotating the gasket 11 in this way, the contact surface between the gasket 11 and the inner surface of the drug syringe 9 can be made free of sticks (adhesion).

Next, the control unit 22 rotates the moving motor 14 in a state where the piston 13 is rotated, and moves the piston 13 to a predetermined position (drug administration end position) in the gasket 11 direction. As a result, the drug 12 pressed by the gasket 11 is discharged via the needle body 27, and the drug is administered (S5 in FIG. 9).

That is, in the present embodiment, the gasket 11 is rotated so that there is no stick (adhesion), and the gasket 11 is moved without the stick (adhesion) (while rotating the gasket 11), so that a stick-slip phenomenon occurs. Does not occur.

Therefore, since the gasket 11 moves at a constant speed, the drug 12 is stably discharged, and the intended amount of the drug can be administered. As a result, appropriate drug administration can be performed.

When the scheduled administration of the drug 12 is completed, the control unit 22 causes the display unit 6 to display that the injection is completed (S6 in FIG. 9), and ends the injection operation (S7 in FIG. 9).

The user recognizes the completion of injection by looking at the display on the display unit 6, moves the main body case 2, and pulls out the needle main body 27 from the injection site. This completes one injection.

As described above, in the present embodiment, the piston 13 is connected to the piston rotation mechanism that rotates the piston 13 around the axis of the drug syringe 9, and the piston 13 is rotated to the gasket 11 on the gasket 11 side. It is provided with a rotational force transmission unit that transmits force.

Therefore, when the piston rotation mechanism rotates the piston 13 around the axis of the drug syringe 9, this rotation is transmitted to the gasket 11 via the rotational force transmitting portion, and the gasket 11 can be rotated about the axis. That is, by rotating the gasket 11, the contact surface between the gasket 11 and the inner surface of the drug syringe 9 can be made free of sticks (adhesion).

Then, when the rotating gasket 11 is pushed toward the injection needle insertion portion 10, the stick-slip phenomenon does not occur because there is no stick (adhesion).

Therefore, since the gasket 11 moves at a constant speed, the drug 12 is stably discharged, and the intended amount of the drug 12 can be administered. As a result, appropriate drug administration can be performed.

Further, since the piston rotation mechanism and the piston movement mechanism are provided independently, the gasket 11 can be rotated independently of the movement of the gasket 11. Therefore, for example, it is possible to change the speed at which the gasket 11 is inserted into the drug syringe 9 while keeping the rotation speed of the gasket 11 constant.

The drug injection device of the present disclosure is expected to be utilized as a drug injection device for injecting a drug such as insulin or growth hormone, for example.

1 Drug injection device 2 Main body case 3 Injection needle mounting part 4 Injection needle 5 Injection button 6 Display 7 Power button 8 Drug syringe mounting 9 Drug syringe 10 Injection needle insertion 11 Gasket 12 Drug 13 Piston 14 Moving motor 15 Screw 16 Nut 17 Moving table 18 Rotating motor 19 Support shaft 20 Piston holding part 21 Battery 22 Control part 23 Drug syringe mounting detection part 24 Storage part 25 Blade 26 Pushing surface 27 Needle body

Claims (5)

A drug syringe mounting part for mounting an injection needle insertion part on the tip side and a drug syringe having a gasket on the inside of the rear end,
A piston that pushes the gasket in the drug syringe mounted on the drug syringe mounting portion toward the injection needle insertion portion.
A piston moving mechanism for moving the piston and
A rotary motor that is connected to the piston and rotates the piston around the axis of the drug syringe.
A rotational force transmission unit provided on the gasket side of the piston and transmitting a rotational force to the gasket is provided .
The piston moving mechanism includes a moving motor that moves the piston along the axis of the drug syringe, and a moving table that is driven by the moving motor and holds the rotating motor and the piston. apparatus. A rotary bearing that rotatably supports the piston is further provided.
The drug injection device according to claim 1 . The rotational force transmitting portion provided on the piston is a convex portion protruding toward the gasket.
The drug infusion device according to claim 1 or 2 . The convex portion is composed of a blade.
The drug injection device according to claim 3 . The piston is moved to the injection needle insertion portion side of the syringe by the piston moving mechanism in a state of being rotated by the rotary motor .
The drug injection device according to any one of claims 1 to 4 .

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