JP2002239003A - Drug solution injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact and portable drug solution injection device in a simple structure capable of being manufactured at a low cost, by which a stable discharge pressure is obtained. SOLUTION: A drug solution chamber 10 whose one end is tightly closed, for which a lid part 60 having the injection and flow-out port of a drug solution is fixed to the other end is internally fitted and disposed, the lid part is projectingly provided on a bottom wall part 40 provided on one end of a cylinder 30 and a piston 50 freely slidably and airtightly moving in the axial direction of the cylinder is internally fitted and disposed. The drug solution chamber is internally fitted to the cylinder so as to be held between the bottom wall part 40 and the piston. When the lid part is fixed to the bottom wall part, the part between the drug solution chamber and the cylinder is turned to an airtight space F. When the drug solution is filled in the drug solution chamber and the airtight space F is vacuumed, the piston is energized by the atmospheric pressure and pressurizes the drug solution chamber trying to return in a bottom wall part direction. When the flow-out port of the lid part is opened, the drug solution inside the drug solution chamber is discharged by the pressurization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for continuously injecting a liquid into an object to be injected at a constant flow rate, and more particularly to an apparatus for injecting a drug solution into a human or animal body. .

[0002]

2. Description of the Related Art For example, when injecting a medical solution such as an infusion solution or an anticancer drug into a patient's body, there is a case where it is desired to inject a certain amount for a long time. Therefore, various infusion pumps are used to continuously inject a chemical solution at a constant flow rate, and are roughly classified into electric and non-electric pumps. Most non-motorized types are disposable, and balloon type, atmospheric pressure type and spring type are sold and used depending on the type of driving pressure source.

[0003]

From the viewpoint of emphasizing the quality of life of patients, there is a demand for a light, small and highly reliable pump. Electric pumps are generally heavy, complex in construction, expensive, and inferior in portability. In the balloon type, the drug solution is filled in the balloon, and the contraction force of the inflated balloon is used as a pressure source to discharge and inject the drug solution in the balloon. Not constant. In the type that uses atmospheric pressure as the pressure source, if the atmospheric pressure is constant, the driving pressure is constant and a stable discharge pressure can be obtained, but commercially available types combine a vacuum generation part and a part that stores the chemical solution in series. Therefore, there is a problem that it is bulky. The type using a spring as a drive source has a problem that the spring itself is heavy and requires a part for accommodating the spring, so that it is bulky. The present invention has been invented in order to solve the drawbacks of the conventional products by providing a chemical solution injection device which has a simple structure, can be manufactured at low cost, is compact, has excellent portability, and can obtain a stable discharge pressure. Things.

[0004]

To achieve the above object, the present invention takes the following technical measures. In order to obtain a stable driving pressure, a structure using the atmospheric pressure is used.
0 was placed in one airtight container structure. Lid 60 having one end sealed and the other end provided with a liquid injection and outlet.
To form a chemical solution chamber 10 which expands and contracts when liquid is filled and discharged under pressure. One end of a cylinder 30 provided with a bottom wall portion 40 having a circular cylindrical portion 41 for fitting and fixing a lid portion 60 of a chemical solution chamber 10 to a cylinder 50, the piston 50 moving slidably and airtightly in the axial direction of the cylinder 30.
Is installed inside. At this time, the chemical solution chamber 10 is fitted inside the cylinder 30 so as to be sandwiched between the wall portion 40 and the piston 50. The present device is configured by providing a protection unit 20 provided with a vent hole 21 at the end opposite to the bottom wall 40 of the cylinder 30. The lid portion 60 is connected to the circular cylindrical portion 41 of the bottom wall portion 40.
, An airtight space F is formed between the chemical chamber 10 and the cylinder 30. When the drug solution chamber 10 is filled with the drug solution and a vacuum is generated in the hermetic space F, the piston 30 is urged to the atmospheric pressure and presses the drug solution chamber 10 to return to the bottom wall 40. When the outlet of the lid part 60 is opened, the pressure discharges the liquid medicine in the liquid medicine chamber 10. By making the liquid injection device in this manner, it is possible to provide a liquid injection device that is compact, has excellent portability, and can obtain a stable discharge pressure.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a chemical injection device according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a state in which a liquid medicine is filled in one embodiment of a liquid medicine injection device according to the present invention. The basic configuration and structure of the liquid injector according to the present invention will be described. The chemical solution chamber 10 of FIG. 1 is a cylindrical bellows-shaped container that is closed at one end and expands and contracts up and down, and has a lid portion 60 at the other end into which a chemical solution injection outlet 61 is incorporated. The chemical solution chamber 10 includes a cylinder 30
Is disposed and fitted in the cylinder 30 so as to be sandwiched between a bottom wall portion 40 provided at one end of the cylinder 30 and a piston 50 which reciprocates air-tightly and slidably in the cylinder 30 in the axial direction. The protection device 20 having the ventilation hole 21 is attached to the opposite end (upper end in the figure) of the bottom wall 40 of the cylinder 30 to constitute the present apparatus. Lid 60 of chemical solution chamber 10
Is airtightly fixed to the cylindrical portion 41 of the bottom wall portion 40.
The deaeration hole 43 of the bottom wall portion 40 is sealed with an obturator 44 to form an airtight space F between the cylinder 30 and the chemical solution chamber 10. In the figure, degassing holes 4 are provided for easy explanation.
FIG. 3 shows the obturator 44 in an unfit state. The purpose of the deaeration hole 43 and the obturator 44 is to facilitate the work of manufacturing the present apparatus, and it is not indispensable. As a method of deaeration, it is conceivable to provide a ventilation groove in the fitting portion of the circular cylinder portion 41 or the lid portion 60 and to plug the groove at the time of fixing.

FIG. 2 is a partial sectional view showing a state before the chemical solution is filled in the chemical solution chamber 10 of FIG. 1 or a state where the chemical solution is discharged. The operation of this example will be described with reference to FIGS. When the chemical solution chamber head 10a is pushed in the direction of the bottom wall portion 40 by the piston 50, the chemical solution chamber 10 is folded so as to have a bellows shape as shown in FIG. At this time, when the deaeration hole 43 of the bottom wall portion 40 is plugged with the obturator 44, the space F between the chemical solution chamber 10 and the cylinder 30 becomes airtight. When a drug solution is injected from the injection outlet 61 of the lid portion 60, the drug solution chamber head 10a is pushed up in the direction of the piston 50.
Moves in a direction away from the bottom wall portion 40, so that the airtight space F between the cylinder 30 and the chemical solution chamber 10 is evacuated. The piston 50 is pushed by the piston 50 so as to be urged to the atmospheric pressure and to return to the original position. Therefore, when the injection outlet 61 is opened,
The chemical in the chemical chamber 10 is discharged.

[0007] The piston 50 is formed so as to slide in an airtight manner on the inner wall of the cylinder 30. An O-ring 51 may be provided around the outer periphery of the piston 50 to ensure airtightness, and a lubricant may be used to smooth the sliding. Or O
Instead of the ring 51, the outer peripheral portion of the piston 50 may be formed by two-color molding of an elastomer material. An inlet and an outlet for the chemical solution may be separately provided in the lid portion 60 and an on-off valve may be incorporated as needed. FIGS. 1 to 4 show an inlet and an outlet for further simplifying the structure of the apparatus. Is formed as an injection outlet 61 which can also be used as one, and a plug 62 is provided. The plug body 62 incorporated in the injection outlet 61 preferably functions as a check valve when injecting the chemical, and has a structure in which the check valve function is opened when discharging the chemical. Such a one-way valve is widely used for medical applications such as a balloon inflation / deflation valve of a bladder indwelling catheter with a balloon. When discharging the liquid medicine from the present apparatus, an extension tube having a connection end for opening the plug 62 is inserted into the injection outlet 61, and the flow rate of the liquid medicine per predetermined time is adjusted in the middle of the extension tube. A flow control device is provided (the extension tube and the flow control device are not shown), and the flow rate of the chemical solution is adjusted.

Referring to FIG. In one embodiment of the liquid injector according to the present invention, the bottom wall portion 40 and the lower end (the lower side in the figure) of the cylinder 30 are screw-fitted to each other. The screw fitting portion 47 is formed so as to be airtight. The chemical solution chamber 10 is assembled to the bottom wall portion 40, and the lid portion 60 is fixedly formed on the cylindrical cylinder portion 41-this will be referred to as a chemical solution portion. In the cylinder 30 to which the protection unit 20 is attached, a piston 50 is fitted and incorporated so as to reciprocate air-tightly and slidably in the axial direction of the cylinder 30-this will be referred to as an urging unit. A deaerator 45 is formed on the bottom wall 40. The one-way valve is built in the deaerator 45 so that the outside air does not flow backward when the airtight space F becomes vacuum. The liquid medicine part and the urging part are assembled in an airtight manner, a syringe is inserted into this deaerator 45, and a vacuum is generated in the airtight space F by evacuating the airtight space F. Similarly, it becomes a chemical liquid injector using the atmospheric pressure as a driving source. In the embodiment of FIG. 1, a deaerator 45 may be formed instead of the deaerator 43 and the obturator 44. By doing so, the procedure for creating a vacuum in the hermetic space F after filling the drug solution chamber 10 with the drug solution is performed. However, there is an advantage that the drug solution can be easily filled because a force for creating the vacuum is not required at the same time as filling the drug solution. The embodiment of FIG. 1 is referred to as an integrated type, and the embodiment of FIG. 3 is referred to as an assembled type liquid injector.

The assembling mold can be prepared by filling the chemical portion in advance with a necessary chemical solution and assembling it with the urging portion when necessary, so that it can be used in a variety of forms compared to a conventional disposable chemical solution injection device. Can be Since the drug solution can be stored by pre-filling a so-called drug solution, for example, when used for home patients who are difficult to visit the hospital frequently, it is necessary to prescribe and store some drug solutions filled with the drug solution in advance. Can be. This is because it is possible to create a certain amount of the standard medicine in advance at the pharmacy department even when it is used in a hospital. Can be reduced and mistakes in medicine can be reduced. If the patient needs to add a drug solution, the patient can be supplemented from the injection outlet 61. If the screw fitting portion of the urging portion is made of durable metal, for example, it can be used a plurality of times, resulting in a very economical liquid injector.

Since the present chemical liquid injector uses the atmospheric pressure as a driving source, the driving pressure is constant unless the atmospheric pressure changes. However, as shown in the hyperbolic characteristic of Boyle's law, a substantially constant and stable vacuum is obtained because the piston 50 also protects the inside of the cylinder 30 from the vicinity of the bottom wall 40 in the present apparatus.
This is a position moved a certain distance in the 0 direction. That is, in order to stably discharge the chemical solution in the chemical solution chamber 10 to the end, a certain vacuum needs to remain in the hermetic space F even when the piston 50 is at the final position where it comes into contact with the bottom wall portion 40. This is referred to as a preliminary vacuum. The configuration of the present invention can easily create a preliminary vacuum. Bottom wall 40
The airtight space F is suctioned from the deaerator 45 using a device having a suction function such as a syringe (not shown). Thus, before the piston 50 moves in the direction away from the bottom wall portion 40, a preliminary vacuum can be generated in the hermetic space F. By the preliminary vacuum, the chemical solution in the chemical solution chamber 10 can be discharged at a stable pressure to the end. In this way, the hermetic space F can be secured with a preliminary vacuum by a simple operation. The preliminary vacuum creating operation may be performed after the chemical liquid chamber 10 is filled with the chemical liquid. For example, when the degassing operation is performed by a syringe, a quantitative operation is performed by instructing the degassing amount using the fact that the degassing amount can be measured by the syringe. Alternatively, when a pressure checker indicating the strength of vacuum is provided so as to ventilate the airtight space F, the vacuum pressure can be confirmed while performing a deaeration operation with a syringe. It is possible to observe whether the hermetic space F maintains a predetermined vacuum by observing with a pressure checker while using the present drug solution injection device, and to perform a deaeration operation when insufficient. FIG.
Pressure checker (detailed structure omitted) is its male part 48a
And the female portion 48b are formed so as to fit with each other. When the male part 48a of the pressure checker 48 is connected to the deaerator 45, and the syringe is inserted into the female part 48b and deaerated, the volume of the syringe can be quantitatively deaerated and the pressure can be confirmed. If a simple commercially available structure in which the color of the display unit changes with the strength of the pressure using the repulsive force of the spring is used, the cost can be reduced with a simple structure.

The dead space D in FIG. 2 will be described. The chemical solution chamber 10 shown in FIGS. 1 to 3 is a cylindrical bellows container that expands and contracts up and down. When the bellows portion of the chemical solution chamber 10 is folded and layered, the chemical solution remains in the chemical solution chamber 10 by the thickness of the layer, and a so-called dead space D occurs. As shown in FIG. 4, by providing a spacer 63 that minimizes the dead space D in the chemical solution chamber 10, this waste can be reduced. The spacer 63 may be attached to the lid 60 or floated in the chemical solution chamber 10. When the bellows portion of the chemical solution chamber 10 is folded and layered, if the height of the spacer 64 is the same as the layered thickness, the dead space D is minimized.

The chemical solution chamber 10 shown in FIGS. 1 to 4 is a cylindrical bellows-shaped container that is closed at one end and expands and contracts vertically, and is made of plastic such as polyethylene or polypropylene. However, the chemical solution chamber 10 does not have to have a bellows shape, and may be a container that expands and contracts up and down when a chemical solution is filled and discharged, so long as the container outer diameter is always kept constant. This is because the place where the vacuum acting as the drive source of the liquid injector according to the present invention is generated must be in the hermetic space F inside the cylinder 30 and outside the liquid chamber 10, so that the flow rate of the liquid injector is substantially constant. Requires a substantially constant vacuum pressure. That is, it is preferable that the outer diameter of the chemical solution chamber 10 does not change even when the degree of vacuum in the hermetic space F changes. For this purpose, for example, it is necessary to ensure the pressure resistance by adjusting the thickness of the chemical solution chamber 10, or to select the material itself. As a thin film material having high pressure resistance, for example, PTCA with little compliance used for coronary dilatation during acute myocardial ischemia
The thin film may be formed in a cylindrical shape using polyethylene or the like used for a balloon. In other words, the chemical solution 10 chamber 10 may have a container shape that fits and folds between the bottom wall portion 40 and the piston 50 and has a constant outer diameter and expands and contracts up and down when filling and discharging the chemical solution.

The protection portion 20 is locked and fixed to the end (upper end in the figure) of the cylinder 30 opposite to the bottom wall portion 40. The protection unit 20 is arbitrarily or carelessly applied an external force other than the atmospheric pressure to the piston 50.
This is a position where the piston 50 does not rise, and is a limit position of the ascent of the piston 50, and has a role of preventing the ascending movement. The protection section 20 is provided with a vent hole 21 so that the upper space of the piston 50 in the cylinder 30 is at the same pressure as the atmospheric pressure at any position in the cylinder 30.

In this liquid injector, the cylinder 30 is made transparent or translucent so that the remaining amount of the liquid in the liquid chamber 10 can be visually measured. By attaching a scale with a correlated position to the cylinder 30, it is possible to provide the convenience of easy measurement.

Referring to FIG. The circumference of the chemical solution chamber 10 can be reinforced with a thin wire 71 so that the outer diameter of the chemical solution chamber 10 does not change or deform due to the vacuum in the airtight section F. In the case of a cylindrical bellows-shaped container that expands and contracts vertically, each of the recesses 70 can be reinforced. However, in order to simplify the process, the unevenness of the bellows is increased from the ceiling to the vicinity of the entrance as shown in FIG. When it is formed so as to be spirally continuous with one line, the concave portion 7 is formed by one thin line 71.
0 can be set along the entire circumference. In addition, both ends of the thin wire 71 are tied so as not to be unraveled. The end of the thin line 71 on the piston 50 side may be hooked on the piston 50.

[0016]

As described above, the requirements for a non-motorized chemical liquid injection pump are pump performance of obtaining a substantially constant flow rate, and
It is compact and excellent in portability, which is small and light, and can be manufactured at a low cost with a simple structure. The drug solution injection device according to the present invention is a drug solution injection pump substantially satisfying the above requirements. In other words, the stable atmospheric pressure is used as an urging source, eliminating the change in the discharge pressure derived from the material found in the type using a spring or a balloon as the urging source, and providing a degassing device to easily create an airtight space. Since a stable vacuum can be secured, a stable flow rate can be secured even when the amount of the filled chemical solution is small. In addition, since the vacuum generating part and the chemical liquid filling part can be housed in one airtight container, the bulk and weight can be significantly reduced as compared with conventional products using springs and vacuum pressure. In addition, since the drug solution injection device of the present invention, which can provide an assembled mold, can be prepared in a prefilled manner, various use forms can be expected as compared with other disposable infusion pumps in comparison with conventional use forms. For example, at the current medical practice, standardization is required as a means of preventing medical errors.However, since the pre-filled drug solution can be used in an assembled drug solution injection device, the conventional drug preparation, which has been performed close to a conventional patient, can be performed in the drug department. And so on,
It can be expected that standardization of some dosing methods will be promoted.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of an example of a drug solution injection device according to the present invention, in which a drug solution is filled.

FIG. 2 is a partial cross-sectional view of an example of the drug solution injection device of the present invention, which is not filled with a drug solution or after ejection, and shows a dead space D.

FIG. 3 is a partial cross-sectional view of an example of the liquid injector according to the present invention, in which the liquid is not filled or after the liquid is discharged, in which a spacer 63 is incorporated.

FIG. 4 is a cross-sectional view of an example of the liquid injector according to the present invention, in which a liquid part and an urging part are screw-fitted.

FIG. 5 is a view showing an example of the liquid injector according to the present invention, in which an outer peripheral portion of a liquid chamber of a bellows-shaped container is reinforced.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Chemical liquid chamber 20 Protection part 30 Cylinder 40 Bottom wall part 50 Piston 60 Cover part

Claims (7)

[Claims] 1. A chemical solution chamber 10 having one end sealed and a lid portion 60 having a liquid injection and an outlet at the other end and having a liquid expandable and contractable under pressure, and a cylinder 30 for internally storing the liquid chemical chamber 10. The cylinder 30 is formed so as to sandwich the chemical solution chamber 10 between the bottom wall 40 provided at one end of the cylinder 30 and the bottom wall 40 provided at one end of the cylinder 30. A piston 50 that is internally fitted into the cylinder 30 and reciprocates air-tightly and slidably in the axial direction of the cylinder 30, and a protection unit 20 is provided at the opposite end of the cylinder 30 where the bottom wall 40 is provided. A medical liquid injector for medical use, wherein a space of a cylinder 30 is formed as an airtight space F. 2. A chemical solution portion in which a lid portion 60 of a chemical solution chamber 10 is fixedly formed on a circular cylindrical portion 41 of a bottom wall portion 40, and a cylinder 30 having a protection portion 20 provided at one end and being open at the other end. An urging portion is formed by internally fitting a piston 50 slidably and reciprocally slidably in the axial direction of the cylinder 30 into the cylinder 30, and the bottom wall portion 40 of the chemical liquid portion and the cylinder 30 open end of the urging portion are formed. 2. The liquid injector according to claim 1, wherein the liquid injectors are formed so as to be airtightly fitted to each other. 3. The chemical liquid injection device according to claim 1, further comprising a degassing device 45 for evacuating an airtight space F between the cylinder 30 and the chemical liquid chamber 10. 4. The liquid injector according to claim 1, wherein the liquid chamber is a cylindrical bellows-shaped container which expands and contracts up and down when the liquid is filled and discharged. 5. A spacer 63 for minimizing a dead space D generated when a bellows portion is folded and layered in a cylindrical bellows-shaped chemical solution chamber 10 which expands and contracts when a chemical solution is filled and discharged. The liquid injector according to any one of claims 1 to 4, wherein 6. The chemical injection device according to claim 1, wherein the outer periphery of the chemical liquid chamber 10 of the cylindrical container which expands and contracts when the chemical liquid is filled and discharged is reinforced by a thin wire 71. 7. A pressure checker 48 for displaying the degree of vacuum of the airtight space F is provided.
The drug solution injection device according to the above.