JPH10263078A - Method and device for measuring bubble generated in tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bubble measuring method and device capable of selecting a tube for use in infusing blood, transfusion or the like into the human body by measuring in advance bubbles generated in a tube holding a solution. SOLUTION: In a bubble measuring device 1 comprising a vacuum pump 2, a pressure regulating valve 3, a pressure sensor 6, a pressure regulation means, and a connection, bubbles are generated by the application of a predetermined negative pressure to the inside of a tube in which a solution has been injected, and the negative pressure is gradually restored to normal pressure to maintain the generated bubbles in a dispersed state to measure the bubbles generated in the tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for measuring bubbles generated in a tube, and more particularly to a tube used for injecting blood or infusion into a human body, particularly a medical tube. The present invention relates to a method for measuring the number of bubbles and a bubble measuring device.

[0002]

2. Description of the Related Art In a transfusion therapy in which a drug solution is administered intravascularly, subcutaneously, intraperitoneally or the like, or a blood purification therapy in which blood is taken out of the body to remove unnecessary substances in the body fluid, the drug solution or blood is passed through a tube circuit. Is to be injected. For example, in hemodialysis, which is a blood purification therapy, an arterial circuit that guides blood from a patient's artery to a dialysis machine, and blood that has been partially removed from the dialysis machine to remove electrolytes accumulated in the blood and supplemented with electrolytes, etc. It has a venous circuit leading to it. The arterial circuit and the venous circuit each have one chamber, and this chamber has a role of trapping air that enters the blood circuit during dialysis. However, even if air in the blood circuit is removed through the chamber, if the blood circuit tube has a property of easily generating or attaching air, bubbles may be generated again after passing through the chamber and grow. In such a case, there is no special means for removing air bubbles, so that blood containing air bubbles may be injected into blood vessels, which may adversely affect the human body.

[0003]

As described above, in order to remove air bubbles naturally occurring in the tube as described above, it is necessary to provide a means such as newly providing an air chamber. However, it is troublesome, costly and bulky. There was such a problem. Further, Japanese Patent Application Laid-Open No. Sho 62-268565 introduces an air bubble detecting device for detecting air bubbles in an infusion tube so that air bubbles such as air do not enter blood vessels when infusing an infusion solution into a human body. This air bubble detection device detects air bubbles by an optical sensor and mechanically or artificially prevents air bubbles from entering the blood vessel based on the obtained air bubble presence / absence discrimination signal. However, even if bubbles are detected during the infusion, a new infusion set must be replaced, which is troublesome and costly, and requires many bubble detection devices to attach the above-mentioned devices to each infusion tube. It was not realistic to actually use. The present invention has been made in view of the above circumstances, and is to select a tube to be used when injecting blood, infusion, or the like into a human body by measuring bubbles generated in a tube containing a solution in advance. Aim.

[0004]

According to the present invention, there is provided a process for generating air bubbles by applying a constant negative pressure to a tube into which a solution is injected, and for generating air bubbles by gradually returning from the negative pressure to normal pressure. And maintaining air bubbles in a dispersed state. The present invention also provides a vacuum pump for applying a predetermined negative pressure to a tube into which a solution has been injected, a pressure regulating valve for regulating the pressure in the device, and a pressure sensor for detecting the pressure in the device. And a pressure measuring means for gradually returning the negative pressure in the device to normal pressure, and a bubble measuring device generated in a tube comprising a connecting portion for connecting a tube containing the solution.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an example. FIG. 1 is an explanatory view showing an example of an embodiment of the present invention, and FIG. 2 is an explanatory view showing an example of a test tube of the present invention. As shown in FIG. 1, the air bubble measuring device 1 of the present embodiment includes a vacuum pump 2 for applying a negative pressure of 700 mmHg to 760 mmHg in the device, a pressure adjusting valve 3 for adjusting the pressure applied to the test tube. A connection portion for connecting a tube containing a solution, pressure adjusting means 5 for gradually returning negative pressure in the device to normal pressure, and a pressure sensor 6 for detecting pressure in the device, These are connected by one line. Further, a buffer container 8 is provided between the vacuum pump 2 and the pressure control valve 3 in order to suppress a fluctuation in pressure in the bubble measuring device 1, and a connection end of the pressure sensor 6 on the device side is provided inside the bubble measuring device 1. A hydrophobic filter 9 or the like may be provided to prevent moisture leaking into the pressure sensor 6 from flowing into the pressure sensor 6.

[0006] The connecting portion 4 comprises a small-diameter tube 42 having an inner diameter of 0.5 to 1.2 mm and branched from the line of the bubble measuring device 1 using a branch pipe 41, and a connector 43 connectable to the test tube 7. The test tube 7 can be easily connected, and the pressure applied to the test tube 7 can be finely adjusted by the small-diameter tube 42. still,
Although a plurality of connecting portions 4 may be provided on the line of the bubble measuring device 1, it is preferable to provide one to three connecting portions 4 in order to apply uniform pressure to all the tubes 7.

The pressure adjusting means 5 has an inner diameter of 0.5 mm to 5 m branched from the line of the bubble measuring device 1 using the branch pipe 51.
m tube 52 and a clamp 5 for adjusting the pressure.
3, for gradually taking the atmosphere into the negative pressure bubble measuring device 1 and returning it to normal pressure. This allows
Positive pressure is gradually applied to the air bubbles generated in the test tube 7, and the air bubbles can be stably maintained in a dispersed state.

When evaluating the performance of a tube using the bubble measuring apparatus 1, first, a test tube 7 as shown in FIG. 2 is prepared. Connectors 71 are provided at both ends of the test tube so that they can be easily connected to the bubble measuring device, and clamps 72 and 73 such as a Robert clamp and a roller clamp which can easily shut off or open the inside of the tube are provided inside the connector 71. It is provided. Then, a clamp 72 is provided so that air bubbles generated in the tube can be easily counted.
It is preferable to make a mark at a certain interval between the clamp and the clamp 73. As a solution to be injected into the test tube 7, purified water produced using a reverse osmosis device is immersed in a thermostat in order to keep the amount of air in the solution constant. Use a constant one. The purified water thus obtained is slowly injected into the test tube using a syringe or the like, and the clamps 72 and 73 at both ends are gently closed so that air bubbles do not enter. After the connector 71 of the prepared test tube 7 is connected to the connector 43 of the connection part 4, the pressure control valve 3 of the bubble measuring device 1 is opened. Subsequently, the vacuum pump 2 is operated, and when a negative pressure of 700 mmHg or less is detected by the pressure sensor 6, the pressure control valve 3 is closed. Next, the clamp 72 of the test tube 7 is slowly opened to gradually reduce the pressure inside the test tube 7 to a negative pressure. When the clamp 72 is left for one minute after being opened, the pressure is gradually increased using the pressure adjusting means 5 to return to normal pressure, and the bubbles generated in the test tube 7 are dispersed and stabilized. Then, the bubbles generated in the test tube 7 are visually observed under illumination, and the number of bubbles is counted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the bubble measuring apparatus of the present invention will be described below with reference to embodiments. Made of polyvinyl chloride, which is evaluated as having little air bubble adhesion at clinical sites, with an inner diameter of 4.7 mm and an outer diameter of 7.
A 0 mm tube X and a tube Y made of polyvinyl chloride, which is evaluated to have a lot of air bubbles and having an inner diameter of 4.7 mm and an outer diameter of 7.0 mm, each having a length of 500 mm, are prepared as shown in FIG. Draw an outer circumference every 100 mm and apply 50 mm from both ends of the tube.
Attach each clamp at the position of mm. The middle part of the tube is divided into three sections, and A, B, and C are set in this order from the side connected to the bubble measuring device. Next, the purified water produced using the reverse osmotic pressure device was placed in a 5 L beaker, and the beaker was immersed in a constant temperature bath at 37 ° C. for 24 hours, and the dissolved oxygen partial pressure in the purified water was 150 mmH.
It was left until it reached g. The purified water is gently injected into the test tube so that air does not enter, and the clamps 72 and 73 at both ends of the tube are gently closed to prevent air bubbles from entering. Three test tubes prepared in this way are prepared, each connected to the connector 43 of the connection part 4 shown in FIG. 1, and the vacuum pump 2 is operated to generate air bubbles in the test tube. The bubbles generated in the test tubes are visually observed under illumination, and sections A, B, and C of each test tube are observed.
For each of the three test tubes,
Table 1 shows the results of counting five times.

[0010]

[Table 1]

From Table 1, it can be seen that the test tube X evaluated as having a small number of bubbles at the clinical site has a small number of bubbles in any of X1 to X3. Further, when the inner surfaces of the test tubes X1 to X3 were observed with an electron microscope, the inner surface conditions were all smooth. On the other hand, the tube sample Y evaluated to have a large number of bubbles at the clinical site has a large number of bubbles compared to the test tube X, although the number of bubbles varies among the tubes Y1 to Y3. When the inner surfaces of the test tubes Y1 to Y3 were also observed with an electron microscope, the inner surfaces of the test tubes with more bubbles were more uneven. From the above results, the evaluation results using the air bubble measuring device of the present invention were consistent with the clinical evaluation, and a good correlation was found between the inner surface state of the tube and the number of air bubbles generated.

[0012]

According to the evaluation method using the bubble measuring apparatus 1 of the present invention, it is possible to objectively distinguish a tube in which bubbles easily occur from a tube in which bubbles easily occur.
For this reason, the use of a tube in which air bubbles are likely to be generated can be prevented beforehand, so that it can be safely administered to a human body when used when injecting a drug solution or blood into the human body.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an example of an embodiment of the present invention.

FIG. 2 is an explanatory view showing an example of a test tube of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air bubble measuring device 2 Vacuum pump 3 Pressure control valve 4 Connection part 5 Pressure control means 6 Pressure sensor 7 Test tube

Claims (2)

[Claims] 1. A step of generating a bubble by applying a constant negative pressure in a tube into which a solution has been injected, and a step of gradually returning from the negative pressure to a normal pressure to maintain the generated bubble in a dispersed state. For measuring bubbles generated in a tube consisting of 2. A vacuum pump for applying a predetermined negative pressure to a tube into which a solution has been injected, a pressure regulating valve for regulating a pressure in the device, and a pressure sensor for detecting a pressure in the device. And a pressure adjusting means for gradually returning the negative pressure in the device to normal pressure, and a bubble measuring device generated in a tube comprising a connecting portion for connecting a tube containing the solution.