JPH01223974A - Minute amount injection pump - Google Patents

Abstract

PURPOSE:To inject a bolus on the way of injection and to prevent the damage of a syringe or the leakage of an electrolyte even after the finish of injection, by surrounding an engaging connection part by a seal rubber material in a slidable manner. CONSTITUTION:For example, a substantially cylindrical syringe 12 having a nozzle 10 at one end thereof and opened at the other end part thereof is formed, for example, by cutting the terminal having a blade of a commercial 2.5ml- injection barrel in a annular shape so as to remove the inner antiskid part thereof and suction rubber is detached from the suction rod attached to the injection barrel and mounted in the syringe to form a slider 14. The semipermeable membrane 20 supported by a metal support net 18 is provided in a cylindrical cartridge 16, which is opened at one end part thereof and sealed at the other end thereof by a flexible bag 26, under tension to demarcate an electrolyte chamber 22 and a water filled chamber 24. The syringe 12 and the cartridge 16 are engaged and connected mutually as shown by Fig.1 and the engaged and connected part is surrounded by a seal rubber material 28. By this method, a bolus can be injected on the way of the injection of a drug liquid.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pump that injects liquid at a constant rate, and more specifically, to a pump that uses the osmotic pressure of the liquid as a driving source to inject a small amount of liquid over a long period of time. It relates to a pump that gradually injects a certain amount of water across the body.

[Conventional technology]

In the medical field, for example, to treat diseases such as cancer, diabetes, infertility, and endocrine disorders, or to relieve patient pain for a long time, medical solutions such as therapeutic drugs and analgesics are administered in small doses continuously. Gradual, long-term infusions may be necessary. - Medications such as anticancer drugs that have severe side effects when administered in large doses, can change the homeostasis of the body when administered in small doses.
Medications such as hormones to maintain the condition have excellent analgesic effects, but
When administering a drug such as rupine, which is dangerous if administered in large quantities at one time, it is necessary to steadily and reliably inject the medicinal solution in small quantities. It goes without saying that the syringe used for such measures must be reliable and stable in operation, but it is also compact and convenient to carry, and the syringe can be moved freely even while in use. It is desirable that there be. The administration of the drugs mentioned above can last for several days depending on the mode of administration, and it is not necessarily given only to patients who cannot move. This is often done on patients whose condition does not change much, and it is harsh to force such patients to rest during the treatment period. Ideally, the patient should not wear the device at all. It is desirable to administer the drug using a syringe that is not recognizable.

Reliability and stability of operation, which are the most basic conditions required for devices that steadily inject small amounts of liquid over long periods of time, are usually achieved by using a motor as the drive source, and mechanical or electrical Alternatively, it can be realized by performing electronic control. Nowadays, motors themselves have become considerably smaller, and control mechanisms can be made extremely small by electronic control using integrated circuits, but there are limits to the miniaturization of the power source used to drive the motors. However, connecting a separate power source and a zero wire will limit the freedom of the patient when wearing the device, so the device actually used has an internal syringe for injection, a motor, a control block, and one power source. It is about the size of a stamp pad and has a built-in syringe, so it is far from being a syringe that the patient is completely unaware that he or she is wearing it.

For example, Japanese Patent Laid-Open No. 60-227773 discloses that it is possible to provide an injector that can be moved freely while being attached by miniaturizing the device without using a motor as a drive source. According to the publication, such an injector is realized by generating pressurized gas in an injection container. However, if the gas pressure is used as the driving line, the reliability and stability of operation will decrease, and by using a gas whose volume easily changes, the total amount of liquid administration will increase proportionally and linearly to the administration time. It becomes extremely difficult to do so, and it is virtually impossible to perform a proportional injection.

The present inventors have roughly devised a syringe-type microinjection pump that utilizes osmotic pressure as shown in FIG. This is semi-transparent inside the cartridge 16! 20 is stretched to define a water filling chamber 24 and an electrolyte chamber 22, and water is filled with water due to osmotic pressure! The injection pump moves from the electrolyte chamber to the electrolyte chamber and uses its pressure to press the seiko rubber 14 inside the syringe.

In this case, the bolus injection (
(Order Party A) cannot be added.

Furthermore, there was the inconvenience that after the injection of the injection liquid was completed, the water filling chamber could only be filled with water equal to or less than the amount of water between the injection liquid in the syringe in order to prevent damage to the syringe and leakage of the electrolyte. .

(Problems to be Solved by the Invention) An object of the present invention is to provide a microinjection pump that injects liquid reliably and stably, is small and convenient to carry, and can be moved freely while being worn while in use. Furthermore, it is an object of the present invention to provide a microinjection pump that is capable of injecting bolus during injection and that does not cause damage to the syringe or leakage of electrolyte solution even after injection is completed.

[Means to solve the problem]

According to the present invention, a semipermeable membrane is stretched inside a cartridge in which one end is left open and the other end is sealed to have a variable volume, thereby defining an electrolyte liquid chamber and a variable volume water filling chamber. Connect the open end of the cartridge to the open end of a syringe with a nozzle on one end, an open end on the other end, and a suction rubber inside, and the osmotic pressure will cause the water to flow from the water filling chamber to the electrolyte chamber. There is provided a microinjection pump in which the injected liquid is introduced by ε[epsilon] by pushing the suction rubber by movement of water, characterized in that the fitting connection portion is slidably surrounded by a sealing rubber material.

If the open end of the cartridge has a cylindrical shape and at least a portion of the cylindrical portion extends outside the syringe, the cartridge can be moved manually during use, and a bolus injection (single injection) can be performed during drug injection. It can be performed.

Fill the syringe with 1!1t of water to be filled into the water filling chamber.
If the amount of injection liquid is larger than rJ, all of the injection liquid in the syringe can be discharged.

If the fitting connection between the syringe and the cartridge is surrounded by a sealing rubber material, and the sliding resistance between the sealing rubber material and the syringe or between the sealing rubber material and the cartridge is greater than the sliding resistance between the slider and the syringe, drug liquid injection is possible. The cartridge does not move inside the syringe, but after ejection is complete, the cartridge moves and the osmotic pressure after ejection can be released by sliding between the seal rubber material and the syringe, or by sliding between the seal rubber material and the cartridge.

In this case, there is sufficient amount of injection liquid, but the amount of water in the water filling chamber is small, and the injection of injection liquid is completed when the water from the water filling chamber ends, and if the syringe is damaged or the electrolyte is If no fluid leaks, check the syringe and cartridge.
By carving a NN joint thread and setting the injection amount for single injection using the scale on the screw, it is possible to perform a single injection of -a certain amount.

The volume-variable water filling chamber of the microinjection pump of the present invention is preferably one in which the volume changes smoothly with the movement of water, and can be constructed from a flexible bag, or may have a cylindrical shape. It can also be composed of a cylinder and a movable rubber that slides inside the cylinder.

[Effect]

Since the microinjection pump of the present invention uses the movement of water due to osmotic pressure as its driving source, it is possible to keep the discharge ω constant, and since it does not require a power source or a motor, it can be miniaturized. Furthermore, the fitting connection between the syringe and the cartridge is slidably surrounded by a sealing rubber material, and a portion of the cylinder of the cartridge extends outside the syringe, so manual injection of the syringe and cartridge is possible if necessary, even during injection. is possible. Furthermore, overload pressure applied to the electrolyte chamber after injection can be released by sliding the syringe and cartridge, thereby preventing damage to the injection pump and leakage of the electrolyte.

〔Example〕

The present invention will be explained in more detail with reference to Examples below.
The invention is not limited only to these examples.

For example, a commercially available 2.5d syringe 12 having a substantially cylindrical shape with a nozzle 10 at one end and an open end
The end of a syringe with wings is cut into a ring shape to remove the internal non-slip part, and the suction rubber is removed from the covering rod attached to the syringe and built into the syringe.
shall be. A semipermeable membrane 20 supported by a metal support net 18 is stretched inside a cartridge 16 that has a cylindrical shape with one end open and the other end sealed using a flexible bag 26.
An electrolyte liquid chamber 22 and a water filling chamber 24 are defined.

The syringe 12 and the cartridge 16 are fitted and connected as shown in FIG. 1, and the fitting connection portion is surrounded by a sealing rubber 28.

The cartridge 16, which is provided with the semipermeable membrane 20, the support net 18, and the flexible bag 26, is produced, for example, as follows.

100g cellulose acetate, 100g formamide
, and 300 g of acetone were thoroughly mixed and dissolved to prepare a membrane forming stock solution, and after removing air bubbles, it was spread on a glass plate using an applicator, left for 30 seconds, and then immersed in water to create a semipermeable membrane. Ru. This semipermeable membrane is washed with running water for 2 hours and then dried at 50°C. After drying, the semipermeable membrane is cut to match the shape of the support, which is a metal net, and attached to one end of a cylindrical body with both ends open, together with the support, to prevent liquid leakage, to form the electrolyte liquid chamber 22. do. In this example, the volume of the electrolyte chamber is 1.0 m, and the effective area of the semipermeable membrane is 1.1 Ci.

Next, the flexible bag is filled with 2.3-m water, and is attached to the semipermeable membrane 20 and the support net 18 as shown in FIG. 1 while being careful not to contain air bubbles. Protect with 30. A through hole 31 is provided in the case 30 to allow communication between the inside and outside of the case.

When constructing a microinjection pump by connecting the cartridge created in this way and the above-mentioned syringe, for example, fill the injection liquid chamber 32 in the syringe 12 with injection liquid in advance, and then pour the injection liquid into the electrolyte liquid chamber 22. The cartridge 16 containing the electrolyte solution made by adding 1 g of sodium chloride to 1 d of water is pushed into the syringe 12, and when the ω of the injection solution reaches, for example, 2.0 d, the pushing is stopped and the injection solution 2.
This is a machine injection pump that can be used in a tatara and can discharge 0 m.

Place the microinjection pump assembled as above into nozzle 1.
When the tube is placed in a constant temperature bath at 37° C. for a discharge test with 0 facing upward and operation is started, the slider 14 moves as water moves due to osmotic pressure, and the injection liquid is gradually discharged from the nozzle 10. Ru. On the way, manually discharge o and is 2 times.
FIG. 2 shows the results of measuring the discharge amount additionally. Roughly, after dispensing the injection solution 2.0-, leave it for 7 days and observe whether the pump is damaged or the electrolyte solution leaks.

As can be seen from FIG. 2, the microinjection pump of the present invention is capable of adding a single injection, and discharges the injected liquid linearly except for the single injection until all the injected liquid is discharged. Furthermore, no damage to the pump or liquid leakage was observed even after the pump was left for seven days after discharging.

Further, the microinjection pump of the present invention, as shown in FIG. 3, can be made in such a manner that the volume-variable water filling chamber is composed of a cylindrical cylinder 34 and a movable rubber 36 that slides inside the cylinder. . That is, when forming the sealed end of the cartridge 16, the cylindrical cylinder 34 is connected and an eight-motion rubber 36 that slides inside the cylinder is provided and sealed.
A metal support 18 is placed inside this sealed cartridge 16.
The semi-permeable membrane 20 supported by the semi-permeable membrane 20 is stretched to define an electrolyte chamber 22 and a water filling chamber 24. The microinjection pump created in this manner can also be handled in the same manner as the above-described one in which the volume-variable water filling chamber is made of a flexible bag, and the same effects can be achieved.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a microinjection pump that injects liquid reliably and stably, is small and convenient to carry, and can be freely moved while being worn while in use. The microinjection pump of the present invention is capable of providing a delivery volume that increases proportionally to the injection time, and single injections can be added during use as needed. It is expected that the use of the microsubmersion infusion pump of the present invention will significantly improve various medical treatments that require continuous administration of small amounts of medicinal solutions.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a microinjection pump of the present invention equipped with a water-filled chamber made of a flexible bag, Fig. 2 is a diagram showing the elapsed time of the discharge amount, and Fig. 3 is a cylindrical cylinder and a diagram showing the inside of the cylinder. FIG. 4 is a sectional view of a microinjection pump of the present invention having a water-filled chamber made of a sliding rubber or the like, and FIG. 4 is a sectional view of a conventional microinjection pump. In Figure 2, the O mark indicates the measurement point? l-0 10... Nozzle 12... Syringe 14.
... Slider (Seiko Rubber) 16 ... Cartridge 18 ... Support net (support body) 20 ... Semipermeable membrane 22 ... Electrolyte liquid chamber 2
4...Water filling chamber 26...Flexible bag 28...
・Seal rubber 30...Case 31...Through hole 32...Injection liquid chamber 34...Cylinder
36...Moving rubber Fl (3, I IG 2 o'clock (h")

Claims (6)

[Claims] (1) A semipermeable membrane is stretched inside a cartridge with one end open and the other end sealed with a variable volume to define an electrolyte chamber and a variable volume water filling chamber, and the cartridge is opened. One end has a nozzle, the other end is open, and the end is fitted and connected to the open end of a syringe that has a suction rubber inside, and water moves from the water filling chamber to the electrolyte chamber due to osmotic pressure. In a pump that injects the injectable liquid by pushing the suction rubber,
A microinjection pump characterized in that the fitting connection portion is slidably surrounded by a sealing rubber material. (2) the open end of the cartridge has a cylindrical shape;
The microinfusion pump of claim 1, wherein at least a portion of the cylindrical portion extends outside the syringe. (3) The microinjection pump according to claim 1, wherein the sliding resistance between the seal rubber material and the syringe, or between the seal rubber material and the cartridge is greater than the sliding resistance between the syringe and the suction rubber. (4) The microinjection pump according to claim 1, wherein the amount of water filled into the water filling chamber is greater than the amount of injection liquid filled into the syringe. (5) Claim 1 in which the volume-variable water filling chamber is made of a flexible bag.
Microinfusion pump as described. (6) The microinjection pump according to claim 1, wherein the volume-variable water filling chamber comprises a cylindrical cylinder and a movable rubber that slides inside the cylinder.