JPH0318468B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to flow control devices.
More specifically, the present invention relates to a flow control device suitable for use in a system for measuring hemodynamic pressure such as blood pressure.

Prior Art In measuring blood pressure, etc., a catheter is usually inserted into a blood vessel at the blood pressure measurement site of a patient, and the catheter is filled with a sterile neutral solution, such as physiological saline. In this case, when blood flows into the catheter from the inner end of the catheter,
In order to avoid the risk of clotting of this blood, it is necessary to flow the neutral solution through the catheter and into the patient at a very slow rate, usually about 3 ml/hr. By monitoring changes in the pressure of the fluid within the catheter, various useful data regarding blood pressure, blood flow, etc. at the inner end of the catheter can be obtained.

The neutral solution is supplied from the container through the catheter into the blood vessel using a pressure difference, but in order to provide such a very slow flow rate, a cylinder with capillary holes is usually provided in the middle. By this,
The fluid is allowed to flow through the pores to provide a predetermined flow rate. Since this flow rate is obtained by the flow resistance of the capillary, the capillary, in other words, the cylinder, requires a certain length sufficient to provide a predetermined flow resistance.

When using such a catheter, it must be completely free of all air which, if introduced into the body, would have a harmful effect on the patient. To remove air within the catheter, the solution is used for priming and the catheter is filled with the solution. however,
This type of method with extremely low flow rates takes too long, so in order to perform this type of priming in a short time, it is recommended to use a method that significantly increases the flow rate when removing air and filling with solution. A flow control device has been proposed.

As such a flow control device, for example, there is one equipped with a fail-safe valve (US Pat. No. 3,675,891), but in this device, the rubber handle is pulled to flush (high-speed flow), so it can be done with both hands. The disadvantage is that it is inconvenient because it requires manual operation.

The housing further includes a housing having a passage provided with an inlet/outlet therein, a valve seat provided in the passage, a valve plunger elastically actuated within the passage and provided so as to be able to engage with the valve seat, and the valve. A marine bore capillary tube extending through the valve plunger to define a low-velocity flow path for liquid from the inlet to the outlet when the plunger is engaged with the valve seat; A flow control device has been proposed that includes means for disengaging a valve plunger from the valve seat so as to define a high-velocity flow path for fluid that reaches the outlet via the valve seat (Japanese Patent Application Laid-open No. 8033/1983). Public bulletin).
However, such a device has a complicated structure and a large number of parts, making it expensive, and also has the disadvantage that it is difficult to vent air inside the device.

Further, an elastically deformable tube having a non-circular outer periphery having a load concentration area, a protective housing extending around the tube, a means for preventing rotation of the tube provided on the housing, and a means provided within the tube. Consisting of a flow rate regulating member with capillary pores and a hollow connector fitted into the tube so as to sandwich the flow rate regulating member at both ends, the load concentration area is located outside both ends of the flow rate regulating member. A hollow portion communicating with the inside of the hollow connector is formed by cutting out a portion of each side, and when the housing is pressed during high-speed flow, the frame inside the housing presses the elastically deformable tube having the non-circular outer periphery. A flow control device has been proposed in which the hollow portions are deformed and the hollow portions are communicated with each other by a hollow formed between the flow regulating member and the tube to form a bypass (US Pat. No. 4,464,179). However, such a device is not only expensive due to its complicated structure, but also twists the elastic tube, which may prevent it from returning to its original state. In addition, in order to form a bypass that communicates between both cavities by deforming the elastic tube, it is necessary to
Since it is necessary to form a tube between the tube and the flow rate regulating member, an extremely large deforming force is required.
Moreover, there was a problem in that it was extremely difficult to form the void so that it had the same cross-sectional area over its entire length.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a novel flow control device. Another object of the invention is to
An object of the present invention is to provide a flow control device suitable for use in a system for measuring hemodynamic pressure such as blood pressure.
Still another object of the present invention is to provide a flow control device that is simple in structure and extremely easy to operate.

These objects include an elastically deformable tubular body with a liquid inlet and a liquid outlet, and at least one capillary hole inserted into the tubular body and communicating with the liquid inlet and the liquid outlet. a cylindrical liquid flow regulating member; at least two recesses partially formed on the inner surface of the tubular body from both end faces to side faces of the fluid flow regulating member and not connected to each other; The housing consists of a housing in which the tubular body is held between pressing members that can press the outside of the tubular body in a direction substantially perpendicular to the axial direction of the tubular body at a location corresponding to the liquid flow regulating member, and A flow control device characterized in that when a member is pressed, only the tubular body is deformed to form a cavity between the tubular body and the liquid flow regulating member that communicates the recessed portion. This is achieved by

Further, the present invention provides a flow control device in which the pressing member has a V-shaped cross section that holds the tubular body therebetween, and is formed integrally with the housing. Further, the present invention is a flow control device in which the tubular body is held between flanges at both ends of a housing. In the present invention, the tubular body on the liquid inlet side is fixed to the housing via the liquid inlet pipe inserted into the liquid inlet through one flange portion, and the tubular body on the liquid outlet side is fixed to the housing through the liquid inlet pipe inserted into the liquid inlet. This flow control device is fixed to the housing via a liquid discharge pipe that penetrates the flange of the liquid discharge port and is inserted into the liquid discharge port. Furthermore, the present invention is a flow control device in which the pressing member has protrusions formed so as to contact the outside of the tubular body from both sides.

Specific Configuration of the Invention Next, an embodiment of the present invention will be described with reference to the drawings. That is, inserting catheters into arteries or veins and monitoring arterial or venous pressure is essential in modern hospitals. When measuring blood pressure, a catheter filled with an infusion agent such as physiological saline is inserted into the measurement site in a blood vessel, and one end is connected fluid-tight to a pressure transducer that converts the pressure into an electrical signal through a tube. The arterial or venous pressure is transmitted through a catheter or tube to a pressure transducer, which converts it into an electrical signal and provides useful data on various display and recording devices.

For example, FIG. 1 is a schematic diagram of a hemodynamic pressure measurement system 1 that includes a pressurized fluid source 2, an IV tube 3, and a flow control device 4 forming an infusion line; The connected tube 5, the catheter 7 placed in the blood vessel of the patient 6, and the pressure transducer 8 constitute a pressure transmission line, and the pressure is displayed and recorded on a display/recording device 9.

2-4 show a flow control device 4 according to the invention. That is, a cylindrical liquid having at least one capillary hole 14 communicating with the liquid inlet 11 and the liquid outlet 12 in an elastically deformable tubular body 13 having a liquid inlet 11 and a liquid outlet 12. A flow regulating member 15 is inserted. This elastically deformable tubular body 13 is made of natural rubber or synthetic rubber such as silicone rubber, butyl rubber, nitrile rubber, chloroprene rubber, SBR, ethylene-propylene terpolymer rubber, etc., preferably silicone rubber, and is used to distribute the liquid. At the location where the regulating member 15 is inserted,
Both end surfaces 15a, 15 of this liquid flow regulating member 15
Recesses 16a and 16b are formed by partially cutting out the inside of this tubular body 13 from b to the side surface. In other words, both the recesses 16a and 16b are blocked by the protrusion 17 formed between them.

This tubular body 13 is housed in a housing 18 that includes a pressing member 19 . This pressing member 19
A protrusion 20 is formed so as to contact the outside of the tubular body 13 from both sides, and both protrusions 2
Pressure acting parts 21, 21 extending outward from 0, 20
is formed. Moreover, this pressing member 19 is
As will be described later, the convex portion 17 formed between the concave portions 16a and 16b is deformed to form the concave portion 16.
Since it is for connecting a and 16b,
The pressing member 19 is formed at a location corresponding to the liquid flow regulating member 15, and is particularly preferably formed integrally with the housing 18. Further, it is desirable that the cross-sectional shape of this pressing member 19 be V-shaped with the tubular body 13 sandwiched therebetween. The housing 18, particularly the pressing member 19, is made of relatively rigid synthetic resin, such as hard vinyl chloride resin, nylon, polypropylene, polycarbonate, ABS resin, or the like.

Further, this tubular body 13 is usually connected to a housing 18.
It is sandwiched and housed between flange portions 18a and 18b at both ends. In this case, liquid inlet 1
The tubular body 13 on one side passes through one flange part 18a and the liquid introduction pipe 22 is inserted into this liquid inlet 11, and the tubular body 13 on the liquid outlet 12 side passes through the other flange part 18b. This liquid outlet 12
Preferably, the tubular body 13 is fixed to the housing 18 by fitting the liquid discharge pipe 23 therein. The inner surface 24 of this liquid introduction tube 22 forms a Luer taper and functions as a female Luer taper connector.

Furthermore, a filter 25 is attached to the inside of the liquid introduction pipe 22, if necessary. If the tip of the tube communicating with the drip tube 3 is made into a male luer taper connector, taper fitting is possible here, and the liquid flows and is introduced into the flow control device 4. This filter 25 is normally installed perpendicularly to the flow direction of the liquid, and the pressurized liquid source 25
or flows out from the drip tube 3. If foreign matter is present in the liquid, it is trapped. The main purpose of this filter 25 is to prevent foreign matter from clogging the capillary pores 14 and obstructing the flow. The filter 25 can be easily attached using a known insert molding method. The opening of the filter 25 is preferably between 10 μm x 10 μm and 50 μm x 50 μm, more preferably between 15 μm x 15 μm and 30 μm.
x30 μm, which is desirable in terms of liquid flow resistance and safety factor during trapping.

The liquid flow regulating member 15 is held between the liquid introduction pipe 22 and the liquid discharge pipe 23 which are inserted from both sides, so that the ends of the liquid introduction pipe 22 and the liquid discharge pipe 23 are connected to the two recesses 16a and 1.
Cutout portions 22a and 23a are formed in at least a portion thereof so as to communicate with 6b, respectively. Alternatively, instead of forming the cutout portions 22a and 23a, a spacer such as a notch ring (not shown) with a portion corresponding to the cutout portion cut out may be inserted to communicate with both the recesses 16a and 16b, respectively. It's okay. The liquid flow regulating member 15 is
Glass, synthetic resins such as epoxy resin, polypropylene, hard vinyl chloride resin, polystyrene,
polycarbonate, nylon, polyacetal,
It is made of polyethylene terephthalate.
The diameter and length of the pore are determined by the pressure of the pressurized liquid source and the slow flow rate, e.g.
If you want to obtain a flow rate of 3 ml/hr at 300 mmHg, the diameter should be 30 to 100 μm, preferably 50 to 70 μm, and the length should be 3 to 100 μm.
It may be 20 mm, preferably 5 to 10 mm. For example, diameter
If the length is 50 μm and the length is 5 mm, a flow rate of 3 ml/hr can be obtained. In this way, a low flow passage is established.

Specific Effects of the Invention Next, the effects will be explained. For example, in a hemodynamic measurement system 1 as shown in FIG.
a flow control device 4 connected to a source of pressurized fluid 2 via a drip tube 3 and to a blood vessel via a tube 5;
When performing priming, as shown in FIG.
6 and 27, the pressing action parts 21 and 21 forming the hinge act as levers, and the tubular body 1
3, a location corresponding to the fluid flow regulating member 15;
In particular, the portion corresponding to the convex portion 17 between the two concave portions 16a and 16b is elastically deformed. That is, since it is elastically deformed upward by the pressing force from the horizontal direction, a gap is created between the fluid flow regulating member 15, which is highly rigid and does not deform, and the tubular body 13, and both the recesses 16a, 1
6b communicate with each other to form a high flow passage 28. If priming is performed at this time, the liquid will mainly flow through the high flow rate passage 28. Within a short time the system is filled with the liquid in the pressurized liquid source 2. In this case, if the pressing member 19 is formed with protrusions 20, 20 as shown in FIGS. 4A and 4B, the upward escape can be stopped when the tubular body 13 is elastically deformed by the hinge force. Flow velocity passage 2
8 can be formed reliably, and the pressing force can be small.

Next, when the tube 5 is connected to the catheter 7 and the pressure on the pressing parts 21, 21 is released, the pressing parts 21, 21 forming a hinge open as shown in FIG. 4A, and the tubular body 13 is opened.
returns to its original shape, and as a result, the high flow rate passage 28 closes, leaving only the low flow rate passage through the capillary pores 14.
Therefore, the liquid supplied from the drip tube 3 passes through the capillary pores 14 via the filter 25 and is supplied to the patient at a predetermined low flow rate, while the desired measurement is performed by the pressure transducer 8.

Specific Effects of the Invention As described above, the present invention provides an elastically deformable tubular body having a liquid inlet and a liquid outlet;
a cylindrical liquid flow regulating member that is inserted into the tubular body and has at least one capillary that communicates with the liquid inlet and the liquid outlet; at least two recesses that are partially formed on the inner surface and are not connected to each other; The housing consists of a housing in which the tubular body is held between a pressing member that can be pressed in a substantially perpendicular direction, and when the pressing member is pressed, only the tubular body is deformed to separate the tubular body and the liquid flow regulating member. Since the flow control device is characterized in that a cavity is formed between the concave portions and the concave portion communicates with each other, a liquid flow regulating member having a length necessary and sufficient to form a low flow velocity passage is provided. Even though the tubular body is used, the area to be elastically deformed due to the recess is small, and since the tubular body is held between the pressing members, it can be elastically deformed with an extremely small pressing force to form a high flow rate passage. A void can be easily formed between the tubular body and the liquid flow regulating member. Therefore, priming etc. can be easily performed. In addition, since the number of parts is small, manufacturing is not only easy and inexpensive, but also the high-speed flow rate and low-speed flow rate can be switched by simply pressing the pressing member, so the switching operation is quick and safe. Furthermore, the crimping force can be set by appropriately setting the outer diameter of the liquid flow regulating member and the inner diameter before crimping of the elastically deformable tubular body or the length of the recess of the tubular body. Excessive pressure (for example, 2 kg/cm ² or more) due to an operational error on the pressure transmission line side can be released to the pressurized liquid source side, thereby preventing the expensive transducer from being destroyed. Furthermore, since the structure is simple and the flow path is linear, the air inside the device can be easily removed.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a state in which a flow control device according to the present invention is incorporated into a hemodynamic pressure measurement system, FIG. 2 is a side view showing an example of the flow control device according to the present invention, and FIG. FIG. 4A is a cross-sectional view taken along the - line in FIG. 3 during low-speed flow, and FIG. 4B is a cross-sectional view taken along the - line in FIG. 3 during high-speed flow. 11...Liquid inlet, 12...Liquid outlet, 1
3... Elastically deformable tubular body, 14... Capillary,
15...Fluid circulation regulating member, 16a, 16b...
Concave portion, 17... Convex portion, 18... Housing, 19
. . . Pressing member, 20 . . . Protruding portion, 21 .

Claims (1)

[Scope of Claims] 1. An elastically deformable tubular body having a liquid inlet and a liquid outlet, and at least one capillary inserted into the tubular body and communicating with the liquid inlet and the liquid outlet. a cylindrical liquid flow regulating member having a cylindrical shape; at least two recesses partially formed on the inner surface of the tubular body from both end faces to side surfaces of the liquid flow regulating member and not connected to each other; The housing comprises a housing in which the tubular body is held between pressing members that can press the outside of the tubular body in a direction substantially perpendicular to the axial direction of the tubular body at a location corresponding to the liquid flow regulating member; Flow control characterized in that when the pressing member is pressed, only the tubular body is deformed to form a cavity between the tubular body and the liquid flow regulating member that communicates the recessed portion. Device. 2. The flow control device according to claim 1, wherein the pressing member has a V-shaped cross section that holds the tubular body therebetween, and is formed integrally with the housing. 3. The flow control device according to claim 1 or 2, wherein the tubular body is sandwiched between flanges at both ends of the housing. 4. The tubular body on the liquid inlet side is fixed to the housing via a liquid inlet pipe that passes through one flange and is fitted into the liquid inlet, and the tubular body on the liquid outlet side is fixed to the other flange. 4. The flow control device according to claim 3, wherein the flow control device is fixed to the housing via a liquid discharge pipe that penetrates through the liquid discharge port and is inserted into the liquid discharge port. 5. The flow control device according to any one of claims 1 to 4, wherein the pressing member has a protrusion formed to contact the outside of the tubular body from both sides.