JPH0417064B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flow control device constituting a blood pressure measurement system.

[Background of the Invention] In recent years, blood pressure measurement systems that can monitor blood pressure and the like over time have been developed and have come to be widely used in actual medical settings.

Generally, a blood pressure measurement system includes, for example, an infusion bag that supplies an infusion agent such as physiological saline to the system, a catheter inserted into a patient's blood pressure measurement site, and an infusion agent filled in the catheter. It is generally composed of a pressure transducer that detects a blood pressure value as a transmission medium, and a display/recording device that displays and records the pressure value output from the pressure transducer.

In other words, in such a pressure measurement system, a catheter is inserted into a patient's artery or vein, and an infusion solution such as physiological saline is supplied to the catheter from an infusion bag at a predetermined, very slow flow rate. . This prevents blood pressure from flowing into the catheter and coagulating, while the pressure transducer detects changes in the pressure of the infusion agent within the catheter and outputs the value to the display/recording device. In this way, the patient's blood pressure status can be monitored in real time.

In this case, in order to set the flow rate of the infusion agent to a predetermined value, a flow control device for regulating the flow rate is usually provided in the conduit that communicates the infusion bag and the catheter. In the flow control device, the flow rate of the infusion solution is controlled to a predetermined low value by flowing the infusion solution through a through hole with a minute inner diameter provided in a capillary tube (resistor).

By the way, in the flow control device, priming is performed in order to remove the air inside the catheter, and in order to perform this priming in a short time,
A device configured to open and close a passage with a larger flow rate than a capillary hole has been proposed.

[Object of the Invention] The present invention has been made regarding this type of flow control device, and it is an object of the present invention to provide a flow control device that can perform priming efficiently and prevent capillary deformation as much as possible. With the goal.

[Means for Achieving the Object] In order to achieve the above object, the present invention provides a flow control device used in a blood pressure measurement system, which comprises an inlet passage and an outlet passage that communicate with each other; A tube member provided with a first bulge that bulges inward from the inlet passage and the outlet passage; a capillary tube made of a resin material and having a through hole with a minute inner diameter; and a tube member made of a harder material than the capillary tube. an outer cylinder member that fits over the capillary tube, and is attached to the first bulge to communicate the inlet passage and the outlet passage; a tubular body that comes into contact with the first bulge and connects the inlet passage; and the outlet passage except for the capillary passage, and define a passage part having a larger flow rate than the passage hole between the inlet passage and the outlet passage, spaced apart from the first bulging part. It is characterized in that it has a second bulge and an elastically deformable closing member that fits onto the tube member.

Furthermore, the present invention provides a method for manufacturing a tubular body having a capillary tube for use in a flow control device constituting a blood pressure measurement system and for reducing the flow rate of fluid such as blood pressure to a predetermined value, the tubular body having a predetermined diameter. A linear body is stretched, then the linear body is surrounded by a resin-based material, and the linear body is further pulled out from the resin-based material to form a capillary tube having a through hole with a minute inner diameter. Features.

Furthermore, the present invention provides a flow control device used in a blood pressure measurement system, which includes a tube member having an inlet passage and an outlet passage communicating with each other, a capillary tube made of a resin material and having a through hole with a minute inner diameter;
a tubular body consisting of an outer cylindrical member that fits over the capillary and is made of a material harder than the capillary; a small flow passage portion located between the inlet passage and the outlet passage; When they come into contact with each other, the flow paths between the inlet passage and the outlet passage other than the small flow passage are closed, and when they are elastically deformed and separated from the small flow passage, a large flow is created between the small flow passage and the small flow passage. and a closing member made of an elastically deformable material that can open the passage as necessary.

[Embodiments] Next, preferred embodiments of the flow control device according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a blood pressure measurement system in which the flow control device is used. That is, in this blood pressure measurement system 10, an infusion bag 12 filled with an infusion agent such as physiological saline is used.
and an infusion tube 14 disposed below it is supported by an infusion stand (not shown), and the infusion tube 14 is supported by an infusion stand (not shown).
4 is connected via tube 16 to the upstream side of flow control device 18 . And this flow control device 1
The downstream side of 8 is connected to a pipe joint 22 via a tube 20. The pipe line branches at one end of the pipe joint 22, that is, a catheter 26 inserted into a blood vessel of a patient 28 through a tube 24 is connected to one end, and a pressure transducer 30 is connected to the other end. A display/recording device 32 is connected to this pressure transducer 30.

Next, the flow control device 18 basically consists of a tube member 40 and a closure member 42 that fits over the tube member 40, as shown in FIG.

The tube member 40 is integrally molded from synthetic resin, such as polycarbonate, and has a substantially cylindrical shape. As shown in FIG. 3, an inlet passage 44 and an outlet passage 46 are defined in the tube member 40, and these inlet passage 44 and outlet passage 46 communicate with each other at the central portion of the tube member 40. Moreover, the pipe member 40
A first bulging portion 48 having a trapezoidal vertical cross section is formed in the center thereof so as to bulge into the inlet passage 44 and the outlet passage 46 . This first bulging portion 48 is provided with a flat portion 48a at its top, and this flat portion 48
Inclined portions 48b and 48c are formed that are inclined together in the axial direction of the tube member 40 so as to widen in cross section from a. Furthermore, a hole 49 is bored in the first bulging portion 48 in parallel to the axis of the tube member 40, and the tubular body 50 according to this embodiment is inserted into the hole 49.

The tubular body 50 substantially consists of an outer cylinder member 52 that fits into the hole 49 and a capillary tube 54 having a minute inner diameter that is internally protected by the outer cylinder member 52, and the capillary tube 54 is connected to the inlet passage 44 and the outlet. aisle 46
is in communication with. In this case, the outer cylinder member 52 is made of metal, for example, stainless steel, and the capillary tube 5
4 is made of a thermoplastic resin, for example, an epoxy resin or a polyester resin that solidifies at room temperature, as will be described later.

On the other hand, a cutout portion 56 is formed at the center of the side surface of the tube member 40 so as to correspond to the first bulge portion 48 .

In addition, in this embodiment, the size of each component of the tube member 40 is selected as follows, for example. That is, the tube member 40 has an outer diameter of 4.9 mm, an inner diameter of 2.0 mm, and a total length of 15.0 mm. The angle of 40 with respect to the axial direction is 30°. Further, the outer cylinder member 52 constituting the tubular body 50 has a total length of 5.0 mm, an outer diameter of 0.7 mm, and an inner diameter of
0.48mm, and the capillary tube 54 has a total length of 5.0mm and an inner diameter of 50μ.
It is m.

Next, the closing member 42 is fitted into the cutout 56 of the tube member 40 . This closing member 42 is made of an elastic material such as silicone rubber. The closing member 42 is liquid-tightly fitted into the open cut material 56 of the tube member 40, that is, in this case, the total length is 10 mm, the outer diameter is 7.7 mm, and the inner diameter is 4.9 mm than the outer diameter of the tube member 40. is selected slightly smaller than .

In fact, a second bulging portion 58 having a trapezoidal longitudinal section shape is formed protrudingly from the distal end portion of the closing member 42 facing the inside of the tube member 40 so as to match the shape of the cutout portion 56. The second bulge 58 has the first
Similar to the bulging portion 48, a flat portion 58a and an inclined portion 58
b, 58c are formed. The inclined portions 58b, 5
8c is formed so that its cross section substantially expands upward. In the normal state, the second bulging portion 58 has the flat portion 58a in contact with the flat portion 48a of the first bulging portion 48 of the tube member 40, and as a result, the inlet passage 44 and the outlet passage 46 are closed. It is configured so that Further, a rod-shaped pull means 60 is attached to the closing member 42 to elastically deform it. That is, a top-shaped space 61 is defined in the center of the closing member 42, and a bulging tip 62 of the pull means 60 is fitted into or bonded to this space 61. In addition, the pull means 60
A handle portion 64 is formed at the tail end of the handle.

The flow control device according to the present invention is basically constructed as described above, and next, a method for manufacturing the flow control device will be explained.

That is, as shown in FIG. 4a, the manufacturing method uses a container 70 made of a thermoplastic resin, such as polypropylene, and having a substantially cylindrical shape. The container 70 has a cylindrical chamber 72 with an inner diameter of 4.7 mm and a total length of 70 mm.
A small-diameter hole 74 communicates with one end of the .

Therefore, the container 70 is set upright with the hole 74 on the lower end side, and one end is fixed to the locking member 76 with a diameter of 50 μm.
m of stainless steel wire 78 is inserted into the chamber 72 of the container 70, and the end of this wire 78 is inserted into the hole 7.
4 to expose to the outside. And the wire 7
A weight 80 with a weight of 20 g is provided at the end of 8. As a result, the wire 78 is stretched in the chamber 72 with a constant tension via the weight 80. In addition to stainless steel, metals such as copper and nickel, or alloys can also be used as the wire 78.

Next, as shown in FIG. 4B, the hole 74 is closed with clay 82 from the outside, and a molten cold-setting epoxy resin 84 is injected from the upper end of the container 70 which is open to the outside. Note that the resin 84
For example, a mixture of Akmex (registered trademark) R161 manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd. and a hardening agent is used.

After pouring the molten resin 84 into the container 70, leave it at room temperature for 24 hours to solidify the molten resin 84,
This is removed from the container 70 together with the wire 78 (see FIG. 4c). Furthermore, if the wire 78 is pulled out from the solidified resin 84, a long capillary tube 54a is obtained (see FIG. 4d), and this capillary tube 54a is cut into predetermined lengths, for example, every 5 mm.
The tubular body 50 is manufactured by fitting the capillary tube 54 into the outer cylinder member 52 .

At that time, both ends of the tubular body 50 are connected to the inclined parts 48b and 48c of the first bulging part 48, as shown in FIG.
It should be formed in accordance with the slope of.

As described above, in the manufacturing method, the wire 78 having a diameter corresponding to the inner diameter of the capillary tube 54 (50 μm in this embodiment) is inserted into the container 70 via the weight 80 with a predetermined tension. Therefore, by pulling out the wire 78, a desired through hole can be easily and precisely formed in the capillary tube 54a. Therefore, we will prevent the occurrence of defective products as much as possible,
An advantage is that the capillary tube 54 with excellent dimensional accuracy can be manufactured efficiently and economically.

Furthermore, a manufacturing method according to another embodiment of the present invention is shown in FIG.

Note that the same components as those in the first embodiment shown in FIG. 4 are given the same reference numerals, and detailed explanation thereof will be omitted.

In this case, as shown in FIG. 5a, in the manufacturing method according to the second embodiment, a stainless steel pipe 86 having a cylindrical shape is used as the container. The pipe 86 substantially corresponds to the outer cylinder member 52 constituting the tubular body 50, and has an outer diameter of 0.7
mm, inner diameter 0.48mm, total length 50mm.

Therefore, after the wire 78 is stretched in the pipe 86 with a predetermined tensile force, the molten resin 84a is injected into the pipe 86 (see FIG. 5b). The molten resin 84a is a polyester resin that hardens at room temperature, and is essentially Eporak (registered trademark) manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd.

Next, a pipe 86 filled with molten resin 84a
The molten resin 84a is heated together with the wire 78 to 60° C. and held for 3 hours to harden the molten resin 84a. Furthermore, by removing the clay 82 and the wire 78 from the pipe 86, a tubular body 50a consisting of the pipe 86 and a capillary tube 54a having a through hole corresponding to the diameter of the wire 78 is manufactured (see FIG. 5c). .
Therefore, by cutting this tubular body 50a into a predetermined length, the tubular body 50 can be obtained.

As described above, in the manufacturing method according to the second embodiment, the capillary tube 54 with excellent dimensional accuracy can be easily formed via the wire 78 similarly to the manufacturing method according to the first embodiment, and in particular, , it becomes possible to utilize the pipe 86 used as a container as the outer cylinder member 52 constituting the tubular body 50. As a result, the manufacturing process of the tubular body 50 is simplified at once, and the tubular body 50 can be manufactured more efficiently.

Furthermore, the tubular body 50 can be manufactured by an extrusion method. In other words, this third
According to this embodiment, a crosshead (not shown) is attached to the extrusion molding machine, and a stainless steel wire with an outer diameter of 100 μm or less, for example, 50 μm, is passed through the crosshead as a core wire, and this wire is constantly loaded with a weight of 80 g.
Pull it with the tension of . Next, extrusion molding is performed by heating the hard vinyl chloride resin to a molding temperature of 140 to 180°C. At that time, an extrusion molded product with wire as a core wire is obtained at a winding speed of 2 m/min, and the wire is pulled out from this extrusion molded product and cut to the desired flow, thereby obtaining a capillary tube 54 with an inner diameter of 50 μm. leading to. Furthermore, the tubular body 50 may be manufactured by inserting the capillary tube 54 into the outer cylinder member 52. Therefore, it is easy to understand that the third embodiment provides the same effects as the first embodiment.

Therefore, the tubular body 50 manufactured by the various methods described above is inserted into the hole 49 of the tube member 40.

Next, in the blood pressure measurement system 10 shown in FIG. do. Further, on the branching side of this pipe joint 22, one side is connected to a catheter 26 via a tube 24.
The other end is connected to the pressure transducer 30. Then, the blood pressure measurement system 10
After completing the circuit connection work, as an infusion agent,
For example, infusion bag 1 filled with physiological saline.
2 and the drip tube 14 are set at a predetermined height using an infusion stand (not shown). As a result, a head pressure corresponding to the height of the drip pipe 14 acts as a differential pressure before and after the flow control device 18.

First, prior to actually measuring blood pressure, so-called priming is performed to fill the pipes that make up this blood pressure measurement system 10 with physiological saline.

Therefore, in priming, the operator pulls the pull means 60 provided on the closing member 42 of the flow control device 18 outward via the handle portion 64 while resisting the elastic force of the closing member 42 itself. . As a result, the closing member 42 is elastically deformed, and as a result,
The second bulge 58 of the closure member 42 becomes separated from the first bulge 48 of the tube member 40 . That is, until now, the flat portion 48a of the first bulging portion 48
and the flat part 58a of the second bulging part 58 were in contact with each other, and communication between the inlet passage 44 and the outlet passage 46 was cut off.
Since a is displaced upwardly, the inlet passage 44 and the outlet passage 46 are brought into communication. Therefore, during this time, a flow path serving as a flush passage is opened, and the physiological saline introduced from the inlet passage 44 through the tube 16 flows through this flush passage at a flow rate higher than that of the capillary tube 54, and the flow passage is passed through the outlet passage 46. It is led out to the tube 20 through. And this tube 2
Physiological saline will be filled in the downstream side of 0 in a short time.

Next, after performing priming as described above and filling the pipe line of the blood pressure measurement system 10 with physiological saline, the tension on the pull means 60 is stopped. As a result, the closing member 42 returns to its original shape, and the flat portion 58a of the second bulging portion 58 comes into contact with the flat portion 48a of the first bulging portion 48, thereby preventing the inlet passage 44 and the outlet passage 46 from communicating with each other. Cut off. Therefore, the flow path in the flow control device 18 is
The flow path is limited only to the capillary tube 54 inserted through the flow path (see FIG. 3).

Therefore, the catheter 26 is inserted into a predetermined part of the artery or vein of the patient 28 to measure the desired blood pressure. Physiological saline dripped from the infusion bag 12 into the drip tube 14 is transferred from the drip tube 14 to the tube 1.
6 into the flow control device 18 from the inlet passage 44 with a head pressure corresponding to its height. This physiological saline is limited to a predetermined low flow rate (in this embodiment, when the differential pressure across the flow control device 18 is 300 mmHg, the flow rate is 3.0 ml/h) through the capillary tube 54, and is , tube 2
4 is passed through the catheter 26 and injected into the blood vessel within the patient 28. During this process, the blood pressure of the patient 28 is detected by the pressure transducer 30 using the physiological saline in the catheter 26 and tube 24 as a transmission medium, and the pressure transducer 30 displays a voltage proportional to the pressure on the display recording device 32. Output to. As a result, the blood pressure value is displayed on the display/recording device 32 in real time.

At that time, in the tubular body 50, the resin capillary 5
4, a stainless steel outer cylinder member 52 is fitted onto the outer cylinder member 52. Therefore, for example, even if an external force acts on the tube member 40, there is no risk that the capillary tube 54 will be deformed because it is protected by the outer tube member 52. Therefore, the inner diameter of the capillary tube 54 can always be maintained at a predetermined value, and the blood pressure of the patient 28 can be measured with high accuracy. Moreover, unlike those using conventional glass tubes, the tubular body 5
There is no possibility of breakage of the 0, which simplifies the handling work and also provides the substantial advantage of being economical.

[Effects of the Invention] As described above, according to the present invention, by separating the second bulging portion from the first bulging portion, a passage portion serving as a flush passage is formed.
No deformation pressure is applied to the tubular body attached to the bulging portion, and it is possible to reliably prevent the minute inner diameter through-hole of the capillary tube constituting the tubular body from being deformed. Therefore, even after flushing is performed a plurality of times, the through hole is not deformed and a desired microflow rate can be reliably maintained. Furthermore, since the metal outer cylindrical member is fitted onto the resin capillary, the capillary is prevented from being deformed, does not break easily like conventional glass tubes, and can be manufactured economically. It is effective.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design are possible without departing from the gist of the present invention. Of course.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a blood pressure measurement system having a flow control device according to the present invention, FIG. 2 is an exploded perspective view of the flow control device according to the present invention, and FIG. 3 is a diagram illustrating the flow control device shown in FIG. Longitudinal cross-sectional view, Figure 4 a to d
5 is a schematic explanatory diagram of a first embodiment of the method for manufacturing a flow control device according to the present invention, and FIGS. 5A to 5C are schematic explanatory diagrams of a second embodiment of the manufacturing method. 10... Blood pressure measurement system, 18... Flow control device, 40... Tube member, 42... Occlusion member, 5
0,50a...Tubular body, 52...Outer cylinder member, 5
4,54a... Capillary tube, 70... Container, 72...
Chamber, 78... Wire, 84, 84a... Resin, 8
6...Pipe.

Claims (1)

[Scope of Claims] 1. A flow control device used in a system for measuring blood pressure, etc., comprising an inlet passage and an outlet passage communicating with each other, and a first tube bulging inwardly of the inlet passage and the outlet passage. a tube member provided with a bulging portion; a capillary tube made of a resin-based material and having a through hole with a minute inner diameter; and an outer tube member made of a material harder than the capillary tube and fitted onto the capillary tube; a tubular body attached to the first bulge to communicate the inlet passage and the outlet passage; and a tubular body that comes into contact with the first bulge to close the inlet passage and the outlet passage except for the capillary hole. At the same time, a second bulging part is provided which is spaced apart from the first bulging part and defines a passage part having a larger flow rate than the through hole between the inlet passage and the outlet passage, and the second bulging part is externally fitted to the pipe member. A flow control device comprising: an elastically deformable closure member.