JPH0194859A - Injector for continuous infusion of trace amount of fluid and its application method - Google Patents

Abstract

PURPOSE:To perform continuous infusion of trace amount of a solution by controlling contracting tendency of a bag within a housing by use of a small amount of air introduced from outside. CONSTITUTION:From an opening made in the lower end of a housing 1, a pipe 2 is protruded. The mouth of an elastic bag 3 is adhered on the inner wall of the pipe 2. On the upper end of the housing 1, a pipe 8 provided with a stopping means 9 and an air permeable membrane 7 are installed. Through the pipe 2, a solution is introduced into the bag 3, and simultaneously flowing in of the solution is assisted by expelling air. When the bag 3 is completely filled with the solution, the stopping means 9 is closed and then the injector is subjected to use by utilizing an equipment which is connected to a flow rate controlling means 5 and a pipe extension part 2A.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention allows liquid stored in a stretchable bag to continuously flow out little by little over a long period of time to the object to be injected. Relates to devices and methods for injection. Maintenance of such a small flow rate is required, for example, when a medical drug solution, such as an anticancer drug, is injected into a patient over a long period of time.

(Prior Art) For medical purposes as described above, there are microflow maintenance devices that employ complex control devices such as microinjection pumps, but in general, they are disposable and as low-cost as possible. What is desired is a device that is simple, easy to handle, and belongs to the concept of a small referee tool.

In order to meet the above requirements, an opening is provided at one end of a cylindrical airtight plastic housing (container), and a stretchable material such as rubber is placed inside the housing so as to communicate with this opening. A device has been introduced that basically consists of storing the bag that has been made and then attaching a thin pipe outward from this opening. (For example, see JP-A-56-102252 and JP-A-58-149280).

(Problems to be Solved by the Invention) The main principles used in these conventional techniques to maintain a minute flow rate are the contractility of the bag that expands and expands to store the chemical solution, and the restriction provided in the pipe. It is a mechanism. When flowing a pressurized liquid out of the pressure system, it is extremely difficult to apply a restriction to reduce the flow rate WR.
In the field of handling very small flow rates like the present invention,
Even if an attempt is made to adjust the flow rate by a restriction, the degree of restriction is large, making it difficult to inject the medicinal solution into the human body over a long period of time. In addition, the flow of liquid may be interrupted due to obstacles such as the outflow pipe used in reality being clogged with some foreign matter or the physical shock that occurs during the outflow process causing air bubbles to form in the constricted area. It had the disadvantage that it was difficult to drain the liquid inside.

(Means for Solving Problems and Effects) The present invention utilizes the shrinkage tendency of the liquid storage bag made of an elastic material provided inside the housing as described above. The purpose is to keep the space under negative pressure and control the shrinkage tendency of the bag by introducing a small amount of air from the outside. That is, when the liquid flows into the bag through the first opening of the housing so as to be connected to the opening of the bag, the air in the remaining space inside the housing is removed according to the expansion and expansion of the bag. The air is discharged to the outside through a second housing opening provided on the end face opposite to the first opening, and at the time of maximum inflation, the second opening is closed to make the remaining space inside the housing other than the bag body under negative pressure.

On the other hand, a film or sheet (hereinafter referred to as "film") that allows a slight amount of air to pass through is fitted in advance on the housing component surface, and from then on, air is introduced from the film, which is the air introduction means, to form the bag. The purpose is achieved by controlling the contraction.

Films that are slightly permeable to air are readily available, such as polybutadiene.

Synthetic resins such as polyester, polyamide, polysulfone, polymethyl methacrylate, polyacrylonitrile, polyvinyl alcohol, polyimide, silicone resin, polyethylene, polypropylene, polymethylpentene, polyvinyl butyral, polystyrene, polycarbonate, or semi-synthetic resins such as cellulose acetate, Furthermore,
glass.

Microporous or porous materials made of ceramics and metals,
Alternatively, it is a non-porous film. A microporous or porous film is a film having pore sizes of 0.1 microns or less.

The selection of the film to be applied depends on the capacity of the bag, the desired liquid release time, the air permeability of the film to be used, its thickness,
The area of the membrane provided on the housing wall, the viscosity of the liquid used,
Considering these factors, the actual amount of air introduced is also affected by the humidity in the air, the shrinkage performance of the bag used, etc. Therefore, we experimentally determined that the air permeability 119 (
The selection and area of the film may be determined.

Practically speaking, the flow rate of the liquid stored in the bag is 0.
08 to 40 cc/br, especially 0.2 to 15
A range of cc/hr is preferred.

On the other hand, for the housing, a cylindrical or rectangular container is practical, but in order to obtain airtightness, it is made with a structure that does not allow air to pass through. The material is polyester,
Examples include synthetic resins such as polyamide, polyvinyl chloride, and polyvinylidene chloride, metals, and ceramics.

Materials for the bag include silicone rubber, butyl rubber, nitrile butadiene rubber, and polyl.

Stretchable materials include 4-butadiene, polyisoprene, polyurethane, butadiene-styrene copolymer, and the like.

(Example) Hereinafter, explanation will be made with reference to the drawings. In Fig. 1.2,
The housing l is a cylindrical airtight plastic container molded to have the required capacity, made of a transparent material for easy viewing of the interior, and its thickness is typically 111 mm.
That's all. The conduit 2 is made to protrude outward from a first opening provided on the lower end surface of the housing 1, and the elastic bag 3 is
The opening is firmly adhered to the inner surface of the conduit 2, and the bag body 3 is set so that the conduit 2 communicates with the inner cavity of the bag. Note that 3A indicates the empty or contracted state of the inner cavity 4 of the bag.

3B indicates a state in which the inner cavity 4 of the bag is filled with liquid or in an inflated state.The volume of the bag in the filled state can be 1 liter or more, but it is usually preferably 100 cc or less.

The inverted trapezoid, referenced 5, is an abbreviation for a three-way valve or other suitable regulating means for controlling and regulating the flow of liquid through the conduit 2.

An air-permeable membrane (or it may be called a film) is fitted into the housing wall so as to have a predetermined area on the upper end surface of the housing l (indicated by reference numeral 7). In the end face, a second opening of the housing l is provided, from which a conduit 8 projects outwards to exhaust the air in the space 6 not occupied by the bag in the housing, and to close the space 6 when the bag is fully inflated. Appropriate sealing means 9 for creating negative pressure
For example, a two-way plug is provided. Note that the illustrated symbol is an abbreviation symbol indicating a two-way plug.

To explain how to use the device described above, a liquid (for example, a medicinal solution) is flowed into the bag body 3 through the conduit 2. 0 which assists the inflow of liquid while simultaneously discharging air from the conduit 8.
When the bag becomes full of liquid m3B, the sealing means 9 is closed, and the flow rate adjusting means 5 and the conductor/i? An instrument (not shown in FIG. 1 but shown in FIG. 3) connected to the extension 2A is used for use.

Incidentally, although not shown in the drawings, the transmission Wy7 can be provided with an appropriate lid and protected with the lid until it is used.

In the above, a three-way stopcock as shown in FIG. 3 described later can be used as the flow regulating means 5. Figure 3 shows
Indicates an injection means that is equipped with a device including a three-way stopcock and has a means for injecting the stored liquid into an injected body (e.g., a human body), and a three-way stopcock instead of a three-way stopcock, or a mixed injection seven-way tube. You can also use .

In the case of FIG. 3, liquid flows into the bag body 3 from the passage 12 of the three-way stopcock 10 using a syringe or the like.

Next, for draining and injecting the liquid, operate the three-way stopcock to use the passage 13 to guide the liquid into the thin injection conduit indicated by the number 14 (usually having an inner diameter of 0.5 to 3-■). Make it.

For the injection conduit 14, a tube made of synthetic resin such as soft polyvinyl chloride, polypropylene, polyethylene, etc. is used. If a mini-clamp 15 is provided in the middle of this tube, the injection of liquid can be easily stopped and restarted.

At the tip of the conduit 14, there is a Luer tapered connector 16.
can also be provided as shown. An intravenous needle, a PSV set, etc. can be connected through the connector 16. Also,
The connector 16 may be equipped with a check valve (not shown) to prevent backflow of liquid due to venous pressure or the like.

Further, as the sealing means 9 of the apparatus shown in FIG. 1, the conduit 8 can be sealed using rubber 24 as shown in FIG. That is, when discharging the air in the housing l, the injection needle 22 is inserted into the rubber 24, and when the air has been discharged, the injection needle 22 is pulled out.

Incidentally, reference numeral 21 indicates a syringe, and 23 indicates a luer taper.If the rubber 24 is air permeable, the rubber 24 can be used in place of the air permeable film 7.

FIG. 5 is a cross-sectional view of another embodiment of the present invention, showing a state in which the bag body is filled with liquid.

In this embodiment, inside the housing 1, there is an elongated cylindrical outer shaft 31 and an inner shaft 32 that is loosely fitted inside the outer shaft 31 so as to be able to slide freely in the axial direction. is an expansion and contraction axis that passes through the center of the bag 33, and corresponds to the expansion and contraction of the bag 33. These axes 31.32 are
Made from synthetic resins such as polycarbonate, polyethylene, polypropylene, etc. The bag body 33 is attached to the aforementioned shaft 31°3.
2, one end of which is airtightly fixed to the outer end of the outer shaft 31 via an O-ring 35, and the other end is similarly fixed to the inner shaft 32.

To explain how to use this device, while expelling air from the conduit 8, a target liquid is flowed into the inner cavity of the bag through the conduit 2. At this time, the time axes 31, 32 are expanded. The sealing means 9 is closed when the liquid becomes full.

Thereafter, although omitted in FIG. 5, injection is carried out via the flow control means connected to the tip of the conduit 2 and the instrument of the conduit extension, as described in FIG. 3. Outflow of the liquid occurs through the gap between the outer shaft 31 and the inner shaft 32, and as the outflow progresses, the shafts 31, 32 contract.

The data shown below is based on the device shown in Figs. 1 and 3, with a hard vinyl chloride resin housing (thickness 1.
Using a silicone gel bag (volume: 40cc when inflated) stored in a 2mm
Table 1 shows the water outflow speed when the following film was used to introduce air into the depressurized housing in order to cause the water to flow out.

Among the experiments shown in Table 1, FIG. 6 shows the change over time in the amount of water flowing out when a porous cellulose acetate film was used. It can be seen from the figure that outflow occurs at a substantially constant outflow speed.

(Effects of the Invention) The present invention makes it possible to easily inject a small amount of liquid into a human body over a long period of time at a minute flow rate using a simple and portable device. Depending on the selection of the air permeable membrane or film, the range of injection time can be freely changed.

[Brief explanation of the drawing]

FIG. 1 shows a sectional view of an embodiment of the device of the present invention.
Contains some abbreviations. FIG. 2 is a perspective view of the housing of the example shown in FIG. 1 with a portion cut away to show the inside. FIG. 3 shows an example of the injection means including the flow regulating means indicated at 5 in FIG. FIG. 4 shows an example of the sealing means indicated by reference numeral 9 in FIG. FIG. 5 shows a sectional view of another embodiment of the device according to the invention. FIG. 6 shows the change in outflow amount over time in an experiment using the apparatus of the present invention. (Explanation of main numbers in the drawings) l Housing 2 Liquid passage conduit 3 Bag body 5 Flow regulating means 7 Air permeable film or sheet 8 Gas passage conduit 9 Sealing means (and above) Fig. 1 Fig. 2 Fig. 3 Figure 4 Figure 5 Procedural amendment (effective 6sho 9, 1986)

Claims (5)

[Claims] (1) A device for injecting a liquid into a bag housed in an airtight housing having a predetermined capacity, storing it therein, then letting the liquid flow out to inject a small amount into a body to be injected, the device is: a stretchable liquid storage bag attached so that a first opening provided in the housing communicates with its inner lumen; and a conduit extending from the first opening to the object to be injected; provided in the housing. A means for discharging the gas in the housing and maintaining a negative pressure in the housing by communicating with another second opening; At least a portion of the wall surface of the housing is configured to control the flow rate of the liquid stored in the bag body. 1. An apparatus for continuously injecting a small amount of liquid, comprising: an air introduction means composed of a film or sheet that allows air to pass through to adjust the temperature of the liquid. (2) The device according to claim 1, characterized in that the film or sheet introduces air into the housing so that the liquid flows out at an outflow rate of 0.08 to 40 cc/hr. A device that continuously injects small amounts of liquid. (3) An apparatus for continuously injecting a small amount of liquid, wherein the object to be injected is a human body, a domestic animal, or a test animal, in the apparatus according to claim 1 or 2. (4) The device according to claims 1 to 3, characterized in that it is provided with flow regulating means for controlling and adjusting the inflow and outflow of the liquid through the conduit communicating with the first opening of the housing. A device that continuously injects small amounts of liquid. (5) In a housing that includes an elastic bag attached to a first opening provided in an airtight housing so that its inner cavity communicates with the first opening, a liquid is supplied to a conduit extending from the opening to make the bag After storing the liquid in the body and discharging the residual gas inside the housing from a second opening separately provided in the housing to maintain negative pressure inside the housing other than the bag body,
By introducing external air into the housing through an air-permeable film or sheet provided on at least a portion of the housing component surface, the liquid inside the bag is continuously flowed out, and the liquid is continuously delivered to the object to be injected. How to microinject.