JPH01135360A - Balloon infuser - Google Patents

Abstract

PURPOSE:To prevent infusion fluid from leaking by covering a balloon infuser with a closed housing and by injecting and discharging infusion fluid via a stopper. CONSTITUTION:A balloon infuser includes a balloon A, a housing B, a controller C for regulating the flow rate of fluid, a tube D for injecting fluid and a joint E. The balloon A is covered with a closed housing B. A projection 15 with a flange 16 is mounted on one end 13 of the housing B, and a stopper is provided in the projection 15. Infusion fluid is injected and discharged from the balloon A via the stopper with a needle 17 of the controller C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a balloon infuser used to continuously inject a predetermined amount of a medicinal solution into a blood vessel, bladder, etc. little by little. More specifically, it is important to ensure that the chemical solution does not leak outside, not only during normal operation, but also in the unlikely event that the balloon ruptures, and also to ensure that the drug solution does not become cloudy or that bacteria or other substances enter the drug solution. Regarding the balloon infuser that can be used.

[Prior Art] Traditionally, as a means of injecting small amounts of medicinal solutions such as antibiotics and anticancer drugs into blood vessels, bladders, etc., the medicinal solution is injected into a balloon made of an elastic material and the contraction force of the balloon is used. A continuous drug injector with a balloon for continuously injecting a drug into a blood vessel or the like over a relatively long period of time has been proposed (for example, Japanese Patent Laid-Open No. 82-11465). The continuous drug injector with a balloon described in the publication has a configuration as shown in FIG. is filled into the balloon (15B) through the inlet hole (154) formed in the tubular body (153).

In this case, the end of the intravascular indwelling device (157) may be closed with your hand to prevent the drug solution from flowing out, or the flow rate valve (157) may be closed with your hand.
8) is performed to the maximum. The predetermined amount of the drug solution filled into the balloon (5B) is filled into the balloon (15[i)
The outflow hole (159) and drug solution spouting part (16
0), is injected into the blood vessel via the intravascular indwelling device (157). It is stated that such a continuous drug infusion device with a balloon has a simpler structure and is easier to handle than the infusion pumps and the like that were used before this device.

However, this device is configured so that the flow rate of the medicinal solution is adjusted by the cross-sectional area of the outflow hole (159), the throttling rate of the flow control valve (15g), the line resistance of the connected vascular catheter, etc. Therefore, there is a problem in that it is difficult to finely adjust the flow rate. Further, the balloon (15B) is arranged in the radial direction ((Y) in FIG. 9) of the tubular body (153).
Since it deforms only in the direction shown by , there is a problem that a considerable amount of the medicinal liquid remains in the tubular body (153) without being injected into the body.

In order to solve the above problems, the applicant first adopted a pipe with micro holes formed on the side for the flow rate control section, and the pipe is expandable not only in the radial direction but also in the axial direction. proposed a balloon infuser with such a balloon portion (Japanese Patent Application No. 1982-204791). This thing has a cylindrical outer shaft (31) as shown in FIGS.
, an inner shaft (32) slidably housed inside the outer shaft (31), and an inner shaft (32) provided outside the shafts so as to cover both shafts, one end of which is attached to the outer shaft (31). Closely fixed,
a balloon part (a) consisting of a balloon (33) made of an elastic material whose other end is closely fixed to the inner shaft (32); and one end of the outer shaft (31) with the inner shaft (32) inside. a stopcock part (b) connected to the end opposite to the side opposite to the side where the chemical solution flows, has a chemical liquid inflow part and a chemical liquid outlet part, and is capable of switching the flow path of the chemical liquid when the chemical liquid flows in or out; a flow rate control unit (c) having a closed pipe (51) at a downstream end connected to a chemical solution outflow unit and having at least one microhole (52) formed in the side thereof; A soft synthetic resin chemical injection tube (d) connected to the tube, and a part of the shunt adapter connected to the tip of the tube (d).
e), characterized in that a synthetic resin filter (50) is provided at an appropriate position between the chemical solution outflow part of the stopcock part and the pipe of the flow rate control part.

According to this balloon infuser, as mentioned above,
By forming micro holes on the side of the pipe and dispensing the chemical liquid through the micro holes, the flow rate accuracy can be significantly improved. A balloon is tightly fixed to each of the freely inserted inner shafts, so that the balloon can expand not only in the radial direction but also in the axial direction, and when the balloon is deflated, the inner shaft is attached to the outer shaft. Since the balloon completely returns to its original state when guided by the balloon, the residual amount of chemical solution can be extremely reduced, which is an effect not found in the prior art.

However, even with the above-mentioned excellent effects of the balloon infuser, there are problems such as the balloon not being stored in a sealed container, which causes the chemical solution to scatter when the balloon bursts, and the three-way stopcock. Since the stopcock is used to inject and dispense the chemical solution into the balloon, there are problems such as a slight leakage of the liquid, the chemical solution becoming cloudy at the stopcock, and the possibility that bacteria may leak from the stopcock. There was a problem that substances such as these could get into the chemical solution.

In view of the above circumstances, it is an object of the present invention to provide a balloon infuser in which the problems of the balloon infuser previously proposed by the present applicant are solved at once. That is, an object of the present invention is to provide a balloon infuser that can reliably prevent leakage, turbidity, and contamination of the medicinal solution with bacteria and the like.

[Means for Solving the Problems] The balloon infuser of the present invention includes: (1) a cylindrical outer shaft, an inner part slidably housed within the outer shaft, and a structure that covers both of these shafts. a balloon made of an elastic material, which is provided on the outside of both shafts, one end of which is closely fixed to the outer shaft, and the other end of which is closely fixed to the inner shaft; and one end of the outer shaft, in which the inner shaft is installed. A balloon part consisting of a side and a drug solution injection stopper inserted into the opposite end;
'2J A housing that houses the balloon part, has the chemical liquid injection stopper solidified on one end surface thereof, and further has a hydrophobic filter attached to an appropriate wall surface; (3) the chemical liquid injection stopper; A chemical injection needle that is pierced,
The present invention is characterized by comprising a flow rate control section including a pipe having at least one fine hole.

[Example] Next, the balloon infuser of the present invention will be explained based on the drawings.

FIG. 1 is a plan view of one embodiment of the balloon infuser of the present invention, showing a state in which the drug solution injection needle is not inserted into the drug solution injection stopper, and FIG. 2 is a plan view of the balloon infuser shown in FIG. 1. An enlarged cross-sectional view of the balloon part of the infuser when it is filled with a medical solution. Figure 3 is an enlarged cross-sectional view of the flow control part of the balloon infuser shown in Figure 1. Figure 4 is the same as that shown in Figure 3. It is a sectional view taken along the line (X)-(X).

In FIGS. 1, 2, and 3, (1) is a balloon infuser according to an embodiment of the present invention, which includes a balloon part (A), a housing (B), a flow rate of 1
It consists of a control part (C), a chemical injection tube (D), and a connector (E). Each part will be explained in detail below.

The balloon part (A) is a part filled with a medicinal solution and a driving part that moves the medicinal solution to the injection site of the human body. Consists of an internal shaft (2), a balloon (3) provided on the outside of both shafts, and a liquid injection stopper (6) inserted into one end of the outer shaft (1). has been done. Outer shaft (
1) and the inner shaft (2) are made of polycarbonate, polyethylene,
The balloon (3) is made of synthetic resin such as silicone rubber, butyl rubber, nitrile butadiene rubber, poly-1,4-butadiene, polyisoprene, polyurethane, butadiene-styrene copolymer, etc. Made of elastic material. Balloon (3)
has a cylindrical shape and is provided outside the outer shaft (1) and inner shaft (2) so as to cover both shafts, one end of which is connected to the outer shaft (1), and the other end is connected to the inner shaft (2). The O-ring (5) is fitted into an annular groove (4) formed on the outer shaft (1) and the inner shaft (2). As mentioned above, the inside of the outer shaft (1) is the part on which the inner shaft (21) slides, and the inside of the outer shaft (1) is the part on which the inner shaft (21) slides. Therefore, it is preferable to provide a clearance of about 0.5 to 30 mm between the inner surface of the outer shaft (1) and the outer surface of the inner shaft (2). 3) can be used in various sizes and thicknesses depending on the amount of drug solution injected into the patient, the injection time, etc., and is not particularly limited in the present invention, but if the approximate values are shown, , the outer diameter is 2~30eo+, the wall thickness is 0.l~2.0cm, and the length is 3~30cIll.Balloon (3)
has a structure that allows it to expand not only in the radial direction but also in the longitudinal direction (the outer axis (1) or the inner axis ('2J axial direction)) by filling it with a chemical solution. It moves in and out of the outer ring (1) as it moves, and the relationship between its position and the amount of drug remaining in the balloon (3) is constant, so by providing a scale on the inner axis (2), You can also check the amount of chemical solution flowing out.

One end of the outer ring (1), the end opposite to the side where the inner shaft ('2J is installed) is made of a rubber-like elastic material such as silicone rubber, and is puncture-resistant (can not be used with a drug injection needle). A drug liquid injection stopper (6) that maintains liquid tightness even when punctured many times and has excellent properties such that the chemical liquid inside does not leak is inserted in an airtight and liquid-tight manner.First - The drug solution injection stopper (6) in the embodiment shown in FIG. Steps (8) corresponding to the shape of the sword, (
9) is formed. And a stopper for drug solution injection (6)
Since the lid part (71) is fixed by the stepped parts [8] and (91), the drug solution injection stopper (6) is inserted and removed by inserting and pulling out the needle when injecting and dispensing the drug solution. The drug solution injection stopper (6) may be fixed using an adhesive.

The housing (B) prevents the balloon (3) from being damaged by contact with sharp objects on the outside, and also protects the balloon from being damaged when it comes into contact with sharp objects. This part functions to seal the chemical solution to prevent it from scattering. Housing (B)
is preferably made of synthetic resin such as polyvinyl chloride, polypropylene, or polycarbonate. The shape of the housing (I3) is not particularly limited in the present invention, and any suitable shape such as a cylindrical shape or a square pipe shape may be adopted, as long as it can be stored so as to cover the balloon (3) after inflation. good. The housing (B) is preferably made of a transparent material so that the injection status of the chemical solution can be visually observed from the outside. Further, the dimensions of the housing (B) are selected in accordance with the dimensions of the balloon (3) when it is inflated.

In the example shown in Fig. 2, there is a clearance between the inner surface of the housing (B) and the balloon (3);
This is not particularly necessary; rather, from the standpoint of miniaturization, it is better to select the inner diameter of the housing (B) to such an extent that the balloon (3) comes into contact with the inner surface of the housing (B).

The housing (B) is intended to cover the balloon part (A) in a sealed state so that the chemical solution does not leak outside even if the balloon (3) is damaged, but if the inside is made completely airtight,
As the medicinal solution is injected into the balloon (3), the air inside is compressed and the pressure increases, causing the inconvenience that the medicinal solution cannot be injected beyond a certain level. Therefore, in the balloon infuser of the present invention, an air vent opening is formed at an appropriate location in the housing (B), and a hydrophobic filter is provided in the opening to allow air to pass through but not to allow the chemical solution to pass through. ing. 1st~
In the embodiment shown in Figure 2, an opening 01) is formed in one end surface of the housing (B), and this opening -
) is provided with a hydrophobic filter OZ to cover it.

The material of the hydrophobic filter 〇'2J is such that even if the balloon (3) is damaged, the chemical solution inside the balloon (3) will not leak out of the 71 Uzing (I3), and that the balloon (
3) It is preferable to use polynis-chill, Teflon, etc. in consideration of the fact that the air inside the housing (B) will be expelled as the balloon (3) expands when a chemical solution is injected into the housing.

A hole 04) for inserting a drug solution injection needle, which will be described later, is formed on the end surface U of the housing (B), which faces the end of the outer shaft (1) into which the drug solution injection stopper (6) is inserted. ing. The hole 04) is formed to be coaxial with the outer shaft (1) and the inner shaft (2), that is, the liquid injection stopper (6), and the lid of the liquid injection stopper (6). Only the - part of part (7) is (
The remaining part exits through the hole 04), which is fitted into the annular groove formed by the steps (8), (9). In addition, the lid part (7) of the drug solution injection stopper (6)
) is made of the material with excellent puncture resistance as described above, the formation of the hole (141) can be omitted.

On the end surface 0 of the housing (B) in which the hole 04) is formed, a substantially cylindrical protrusion 6 is formed coaxially with the hole (14). A hook portion 0 is formed at the tip of the protruding portion 4, and is connected to an end portion on the liquid injection needle side of a flow rate control portion (C) to be described later. When providing the protrusion 6 in this way, there is a risk that the chemical solution may adhere to the surface of the lid (7) of the drug injection stopper (6) when the drug solution is injected into the balloon (3). Even if the balloon infuser is operated, this chemical solution can be reliably prevented from coming into contact with the hands of the person operating the balloon infuser. In addition, the housing CB) and the flow rate control part (C)
The connection can be made by simply sticking the needle (+7) into the drug solution injection stopper (6), but it can be done by fitting or screwing the protrusion G and the drug solution injection needle side end 09. is preferable.

The flow rate control unit (C) is a part that controls the flow rate of the chemical solution,
A pipe having at least one micropore is provided in the flow path of the chemical solution, and the flow rate is controlled by allowing all of the chemical solution to pass through the micropore. A drug solution injection needle (17) is attached to one end of the flow rate control unit (C), and by inserting this drug solution injection needle 07) into the drug solution injection stopper (6), the balloon (3) is filled in advance. The stored chemical solution can be guided to the flow rate control section (C).

As the pipe with micropores, a pipe with a closed downstream end, which was adopted in the balloon infuser proposed earlier by the present applicant, may be used, or other perforated pipes such as a porous glass pipe may be used. Good too.

First, the case of using a pipe whose downstream end is closed will be described based on FIGS. 7 and 8. The drug solution flows into a drug solution injection tube, which will be described later, through the micropores. The diameter of the micropores may be appropriately selected depending on the type of chemical solution, flow rate, etc., and in the present invention, it is generally 20 to 100 microns, although it is not particularly limited. Depending on the flow rate of the chemical solution, it may be possible to accurately control the flow rate by forming only one micropore, but it is important to consider the need for accurate control of the flow rate, especially when using highly viscous chemical solutions. In this case, it is generally preferable to form a plurality of holes as small as possible.

When using such a pipe, the drug solution injection needle (171
It is necessary to provide a filter (50) made of synthetic resin such as nylon between the pipe of the flow control section (C) and the pipe of the flow rate control section (C). As the filter, a membrane filter such as a mesh filter, a filter made of woven fabric, a non-woven fabric, etc. can be suitably used, but it is also possible to use a layered filter made of a sintered body of polypropylene. be. The pore size of the filter is determined in consideration of the relationship with the pore size of the micropores formed in the pipe of the flow rate control section (C). In other words, the filter is provided to prevent the micropores formed in the pipe from becoming clogged with foreign matter in the chemical solution, preventing the prescribed flow rate from flowing, or in the worst case, preventing the chemical solution from flowing at all. When considering this point of view, the pore diameter of the filter needs to be smaller than the pore diameter of the micropores of the pipe. Specifically, the diameter of the micropores in the pipe was set to 6.
When it is 0 micron, the average pore size of the filter is 50
It is better to set it to less than a micron. Note that it is preferable to use stainless steel as the pipe in which the micropores are formed from the viewpoints of chemical resistance, workability, non-toxicity, etc. However, it is preferable to use a pipe made of stainless steel as long as it has the above-mentioned characteristics. A pipe may be used, and synthetic resin such as polycarbonate, polypropylene, ABS resin, etc. may also be used.

Next, as a pipe with micro holes, the pipes shown in Figs. 1 and 3 are
The case where a porous glass pipe is used as shown in the figure will be explained. Porous glass pipe Oa is produced by forming borosilicate glass into a pipe using a normal method, and
It is manufactured by phase-separating the glass through heat treatment at a temperature of about 0.00°C, followed by acid treatment.This pipe has heat resistance, chemical resistance, and features uniform pores, with a pore diameter of 0. It is a pipe that has many holes of about .1 to 3.0 microns on its side. The length and inner diameter of the pipe may be appropriately set depending on the intended flow rate and viscosity of the chemical solution, and are not particularly limited in the present invention, but are approximately 2 to 20 o+n and 0.5 to 5 III1, respectively.
1 is a guideline, 5-15IIIll and 1-3I
Preferably it is II11. Also, the thickness of the pipe is 0.
5 to 5 IIlffl is preferred.

When such a porous glass pipe is used, there is an advantage that the accuracy of flow rate control can be further improved compared to the case where a stainless steel pipe having micropores as described above is used. That is, when drilling microscopic holes in a pipe, the lower limit of the hole diameter that can be drilled is about 15 microns, and therefore there is a limit to the number of holes that can be drilled. Therefore, if the filter is used for a long time, some of the micropores may become clogged with dirt between the filter and the micropores, making the flow rate unstable. On the other hand, when a porous glass pipe is used, since many holes are formed on the side of the pipe, even slight clogging will not cause the flow rate to become unstable.

When using a porous glass pipe, if air bubbles are mixed in the chemical solution, the so-called air block phenomenon (air cannot advance into the micropores due to the surface tension of the chemical solution filling the micropores). In order to prevent this phenomenon, a hydrophobic material for air venting is installed upstream of the porous glass pipe to prevent this phenomenon. Preferably, an air vent (21) with a filter is provided.

Next, the third to fourth embodiments of the air vent part (21) will be explained.
This will be explained based on the diagram. In the embodiment shown in Fig. 3, the air vent section (21) is constituted by a short cylindrical space, and one side of the short cylinder (the side shaded in Fig. 3) is made of a hydrophobic filter. An air vent filter is provided. However, in order to make the figures easier to understand, the filter is drawn transparent in FIGS. 3 and 4. This is a plate-shaped baffle plate, which is provided within the air vent part (2η) so as to be in contact with the filter and the bottom surface Q4 of the flow rate control part (C) constituting the short cylindrical space (see FIG. 4). Since the chemical liquid advances in an S-shape as shown by the arrow in FIG. 3, it is possible to prevent the chemical liquid that has passed through the chemical injection needle On from directly reaching the porous glass pipe Oa.

Then, while the chemical liquid moves in an S-shape, air bubbles contained in the chemical liquid (see FIG. 4) are discharged to the outside through an air purge filter. The distance (g) between the air vent filter and the bottom circle of the flow rate control section is preferably as narrow as possible to ensure that even small air bubbles come into contact with the filter. omI
It is preferably 11, particularly preferably 0.1 to 0.51. Note that the arrangement of the baffle plates may be such that the chemical solution does not easily reach the porous glass pipe OF3, and is not limited to that shown in FIGS. 2 and 3. Further, the shape of the filter and the shape of the air vent (211) are not limited to those of this example, and may be selected as appropriate.

The porous glass pipe Q81 and a chemical liquid injection tube (D) described later are connected and fixed by a fixing member.

In this embodiment, a chemical liquid injection tube (D) made of a soft synthetic resin such as soft polyvinyl chloride, polypropylene, or polyester is connected to the human body side of the flow rate control section (C). The inner diameter, wall thickness, and length of the tube (D) may be appropriately selected in consideration of the amount of the chemical solution and the mode of use. If a mini clamp (30) is provided in the middle of the tube (D),
This method has the advantage of being able to easily stop and restart the injection of the drug solution.

A Luer tapered connector (E) is provided at the tip of the drug solution injection tube (D).
Intravenous needles, PSv sets, etc. are connected via the. The connector (E) may be equipped with a check valve (not shown) to prevent the medical solution from flowing back due to venous pressure or the like.

Next, a method of using the balloon infuser of the present invention will be explained.

The drug solution is injected by inserting a needle (not shown) of a syringe into the hole 04) and sticking the needle into the drug solution injection stopper (6). As the balloon (3) is filled with the medical solution, it expands in both the radial and axial directions. When a predetermined amount of the drug solution has been filled, the injection needle is removed from the drug solution injection stopper (6). At that time, even if the drug solution were to adhere to the lid (7) of the drug solution injection stopper (6), the lid (7)
7) is located in a recessed area, so there is no possibility that the operator will touch this chemical solution with his or her hands.

Next, the drug solution injection needle 0 of the flow rate control section (C) is inserted into the drug solution injection stopper (6). At that time, the drug solution is in the tube (D)
It is necessary to keep the mini clamp ■ in a stopped state to prevent it from flowing towards the

After that, connect the P
After connecting to an S-set, a balloon catheter, etc., and performing predetermined operations such as air bleeding, a medicinal solution is injected into the patient's body.

FIG. 5 is a diagram showing the flow rate characteristics of a balloon infuser according to an embodiment of the present invention, and shows the results of filling a balloon with 40 ml of physiological saline and measuring the relationship between injection time and injection amount. ing. In FIG. 5, O mark indicates a balloon infuser according to an embodiment of the present invention (average pore diameter in the flow rate control section is 0.22 microns, outer diameter is 3.0111 mm).
11, using a porous glass pipe with an inner diameter of 2.0 mm).
Balloon infuser proposed in No. 240159 (
The flow rate characteristics of a stainless steel pipe with an outer diameter of 0.911111 s and an inner diameter of 0.6 mm in which one fine hole with a hole diameter of 60 microns was formed in the flow rate control section are shown. Fifth
In the measurement example shown in the figure, the flow rate accuracy of the balloon infuser of the present invention is approximately -1,5% (39,5-40,0/
40. OX 100), whereas that of the balloon infuser proposed earlier is about -10% (38,0-40,0/40.OX 100),
It can be seen that the balloon infuser of the present invention exhibits a stable medicinal liquid ejection pace, that is, a good medicinal liquid ejection amount.

The balloon infuser of the present invention is lightweight and easy to handle, so depending on the location where the drug is injected, the patient can put the housing in his pocket and walk while injecting the drug, giving the patient greater freedom of movement. is improved.

[Effects of the Invention] As explained above, the balloon infuser of the present invention can provide the following effects.

■The housing that covers the balloon is a sealed type, so
Even if the balloon is damaged, the medicinal solution is prevented from leaking to the outside.

■Since there is no flow switching part such as a three-way stopcock, it is possible to prevent the chemical solution from becoming turbid and to prevent bacteria from entering the chemical solution from the flow path switching part.

■Since the drug solution is injected and dispensed through the drug solution injection stopper, there is no leakage of the drug solution, and even if the drug solution adheres to the surface of the stopper after the drug solution is injected, the Because the body is located in a deep position where it cannot be exposed directly to the outside,
There is no risk of the chemical solution coming into contact with your hands.

■When using a porous glass pipe for the flow rate control section, there is less possibility of the flow rate becoming unstable due to clogging than when using a pipe with micro holes, which further improves flow rate accuracy. can be done.

[Brief explanation of the drawing]

FIG. 1 is a plan view of one embodiment of the balloon infuser of the present invention, showing a state in which the drug solution injection needle is not inserted into the drug solution injection stopper, and FIG. 2 is a plan view of the balloon infuser shown in FIG. 1. An enlarged cross-sectional view of the balloon part of the infuser when it is filled with a medical solution. Figure 3 is an enlarged cross-sectional view of the flow control part of the balloon infuser shown in Figure 1. Figure 4 is the same as that shown in Figure 3. (X)-(X) line schematic cross-sectional view, FIG. 5 is a diagram showing the flow rate characteristics of a balloon infuser according to an embodiment of the present invention, and FIG. A plan view of one embodiment, FIG. 7 is an enlarged sectional view of the flow control section of the balloon infuser shown in FIG. 6, and FIG. 8 is an enlarged view of the tip of the pipe of the flow control section of the balloon infuser shown in FIG. 7. 9 are longitudinal sectional views of a conventional balloon infuser. (Main symbols in the drawing) (1); Balloon infuser (A); Balloon part (B): Housing (C): Flow rate control part (D): Chemical injection tube (E): Connector (1): Outer shaft (a: Inner shaft (3): Balloon (6): Liquid injection stopper 07): Liquid injection needle 0F3 = Porous glass pipe Figure 3, Port 4 and d<

Claims (1)

[Scope of Claims] 1 (1) A cylindrical outer shaft, an inner shaft slidably housed within the outer shaft, and an inner shaft provided outside the shafts so as to cover both shafts. A balloon made of an elastic material has one end tightly fixed to the outer shaft and the other end tightly fixed to the inner shaft, and the balloon is inserted into one end of the outer shaft opposite to the side where the inner shaft is inserted. (2) the balloon part is housed, the drug solution injection stopper is fixed to one end surface of the balloon part, and a hydrophobic filter is attached to an appropriate wall surface; (3) a drug solution injection needle inserted into the drug solution injection stopper;
A balloon infuser comprising a flow control section comprising a pipe having at least one micropore. 2. A protrusion having a substantially cylindrical flange that is substantially coaxial with the center of the stopper is formed on the end surface of the housing to which the drug solution injection stopper is fixed, and the protrusion is located on the drug solution injection needle side of the flow rate control unit. The balloon infuser according to claim 1, which is configured to be fitted or screwed together with the end portion. 3. The balloon infuser according to claim 1, wherein the pipe of the flow rate control section is a porous glass pipe. 4. The balloon infuser according to claim 3, wherein an air vent part is formed as a flow rate control part and has an air vent filter made of a hydrophobic filter upstream of the porous glass pipe.