JPH08141072A - Blood circuit valve - Google Patents

Abstract

PURPOSE: To form the sliding part of a blood circuit valve which changes over blood circuits as a sliding part which has a small coefft. of friction and less abrasion wear and does not adversely affect the living body. CONSTITUTION: An outside frame 1 and a valve body 10 are formed of rigid resin materials. Port pipes 1a, 1b, 1c to be connected with pipes 3 are integrally formed in the outside frame 1 and a changing-over hole 12 of T-shape is formed in a selector 11 of this valve body 10. The outer peripheral surface (a) of the selector 11 is rotationally slid by the inner peripheral surface (b) of the housing part 1e of the outside frame 1 and the circuits of the respective pipes 3 are changed over by the rotational action. Films of a DLC or BN, etc., are formed via a stabilizing layer of a Cm Hn polymer on the resin surface of the outer peripheral surface (a) of the selector 11. These films have excellent mechanical characteristics and the rotational sliding characteristics of the valve body 10 are improved. The films are bioaffinity films and have no adverse influence on the living body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood circuit valve installed in a blood circuit that circulates blood from a blood vessel inside the living body to the outside of the living body, and particularly wear resistance to a sliding portion for switching the circuit. The present invention relates to a blood circuit valve in which a membrane having high temperature, chemically stable, and good biocompatibility is formed.

[0002]

2. Description of the Related Art For example, when performing artificial dialysis, a blood vessel for circulating blood is formed by connecting a blood vessel inside the living body and an artificial dialyzer outside the living body by a pipe made of resin, and is led out from the living body. The waste in the blood is removed by an artificial dialyzer, and the blood from which the waste is removed is returned to the blood vessel again.

In this blood circuit, blood such as a three-way stopcock for switching the circulation route of blood in the artificial dialyzer and the route of derivation of blood from the blood vessel in the living body or introduction of blood into the blood vessel. Circuit valves are used.

In this type of blood circuit valve, a synthetic resin valve body is housed inside a synthetic resin outer frame, and an inner surface of the outer frame and an outer surface of the valve body slide with each other. Has become. For example, a T-shaped three-way hole is formed in the valve body, and the blood circuit is switched by sliding and rotating the valve body at the sliding portion.

[0005]

In this blood circuit, it is ensured that the circuit is switched by the blood circuit valve, and it is possible to prevent the blood from leaking or mixing between the paths of the blood to be switched. There is a need. However, the blood circuit and the blood circuit valve used for artificial dialysis and the like are used for a long time, and in the blood circuit valve, the switching operation for rotating the valve body is repeatedly performed. Therefore, when the outer frame that constitutes the sliding portion of the blood circuit valve and the valve body are formed of synthetic resin, the friction between the resins increases as the usage time increases, and the switching operation between circuits is prevented. In some cases, it may not be possible to carry out smoothly, and if the sliding portions of the resins wear, the risk of blood leakage and mixing increases as described above.

Therefore, in order to prevent the friction coefficient from decreasing and the abrasion amount from increasing due to long-term use and increase in the number of sliding operations, silicone oil or the like is applied to the outer frame, the valve body, and the sliding portion. A lubricant is applied and used. However, when the amount of silicone oil applied is increased, a slight amount of impurities contained in the oil may be mixed into blood, which may adversely affect the living body. On the other hand, if the amount of silicone oil applied is too small, the slidability of the sliding parts between the resins cannot be sufficiently improved, and the amount of friction and wear will increase.
Therefore, in the process of manufacturing the blood circuit valve, a very difficult assembling work of uniformly applying an appropriate amount of silicone oil to the sliding portion is required.

The present invention solves the above-mentioned conventional problems, and the friction coefficient and wear amount of the sliding portion can be reduced without using silicone oil or the like. It is an object of the present invention to provide a blood circuit valve that does not adversely affect the living body.

[0008]

The present invention is a blood circuit valve installed in a blood circuit for circulating blood from a blood vessel inside the living body to the outside of the living body, and forms a sliding portion for switching the circuit. DLC (diamond-like carbon) on the surface of resin
It is characterized in that a film is formed.

Further, the present invention is a blood circuit valve installed in a blood circuit for circulating blood from a blood vessel inside the living body to the outside of the living body, wherein the surface of a resin forming a sliding portion for switching the circuit. , BN, HfN, TiN, ZrN, ReN
(However, Re is a rare earth element of Y, La, Ce, Dy, Eu, or Yb), and is characterized in that a nitride film is formed.

A C _m H _n polymer layer is preferably provided as a stabilizing layer on the surface of the resin.

In the above description, the blood circuit valve is, for example, a three-way stopcock, the valve body is housed inside the outer frame made of synthetic resin, and the inner surface of the outer frame and the outer surface of the valve body serve as a sliding portion. In the case of a three-way stopcock, a T-shaped switching hole is formed in the valve body. However, the blood circuit valve of the present invention is not limited to the three-way stopcock, and may be a four-way stopcock, a stop valve for closing and opening the circuit, or the like.

[0012]

[Function] Diamond-like carbon (DLC)
arbon) consists of carbon only or carbon and a small amount of hydrogen, and locally has a bond similar to diamond, and has a property similar to diamond. Since it is a bond similar to diamond, it has excellent mechanical properties in terms of hardness and wear resistance, has excellent corrosion resistance, and also has a low friction coefficient and excellent lubricity. In addition, it is chemically inert and chemically stable, and because it is mainly composed of carbon, it has biocompatibility, has excellent blood compatibility, does not deteriorate in vivo, and has excellent antithrombotic properties. It is a thing.

Further, since the nitride has a stable crystal structure in which each element and nitrogen ion are strongly bonded by ionic bond, the nitride has excellent mechanical strength and hardness, a small friction coefficient, and a sliding property. It also has excellent dynamic characteristics. In addition, it is chemically stable and therefore has excellent biocompatibility.

Hexagonal BN (boron nitride) has a structure and physical properties very similar to those of graphite and is soft and delaminated. On the other hand, cubic BN (Cubic-BN) has a structure and physical properties very similar to those of diamond, and is excellent in mechanical properties such as hardness and wear resistance. Therefore,
As a material used for the sliding portion of the blood circuit valve, it is preferable to use a mixed crystal BN composed of a hexagonal crystal component and a cubic crystal component.

When diamond-like carbon or nitride, especially mixed crystal BN, etc. as described above is deposited on the sliding portion of a blood circuit valve, it has excellent mechanical properties such as wear resistance, corrosion resistance and hardness. A sliding part can be obtained. Therefore, even if the valve is repeatedly used for a long time and the switching of the valve is repeated, abrasion or separation of the sliding portion is unlikely to occur, the sliding characteristic of the valve does not deteriorate, and smooth circuit switching is always possible. Therefore, there is no need to apply silicone oil to the sliding parts,
There is no risk of impurities entering the blood. In addition, since all the substance films are chemically stable, they have excellent biocompatibility.

In particular, a film such as DLC or BN is excellent in peeling resistance and hardly peels off from the surface of the sliding portion. However, in order to prevent this kind of substance film from peeling off from the sliding part, the surface of the resin of the sliding part is activated by a mixed plasma of a gas such as argon (Ar) and hydrogen to chemically modify it. After the application, it is preferable to form a C _m H _n polymer as a stabilizing layer and form a material film such as DLC or BN thereon.

[0017]

Embodiments of the present invention will be described below. Figure 1
It is an exploded perspective view showing a three-way stopcock as an example of the blood circuit valve of the present invention. This three-way stopcock is provided, for example, in a blood circuit that connects a blood vessel in a living body and an artificial dialyzer.
The outer frame 1 of the three-way stopcock is made of transparent hard synthetic resin.
The outer frame 1 has a cylindrical shape with a bottom, and mouth pipes 1a, 1b, 1c are integrally formed at three locations on the outer periphery of the outer frame 1, and the male screw portion 2 is formed on the outer peripheral surface of the tip of each mouth pipe 1a, 1b, 1c. ，
2, 2 are formed. Blood circulates inside the pipe 3, and is made of a transparent material such as soft synthetic resin. Each of the pipes 3, 3, 3 is provided with a connector 4, 4, 4 and the connectors 4, 4, 4 are screwed onto the male screw portions 2, 2, 2 so that the pipe 3, 4.
3, 3 and the mouth pipes 1a, 1b, 1c are connected.

On the inner peripheral surface of the outer frame 1, a step 1d is provided on the upper side, and a portion on the bottom side of the step 1d is a storage section 1e. The valve body 10 is a switching body 11 having a columnar shape below the step 11a. The switching body 11 is inserted into the storage portion 1e of the outer frame 1. The outer peripheral surface (a) of the switching body 11 and the inner peripheral surface (b) of the storage section 1e are formed with high precision so that they can slide with little clearance, and the step 11
By fitting a with the step 1d, the switching body 11 is prevented from coming out of the storage portion 1e. A T-shaped switching hole 12 is formed inside the switching body 11, and when the switching body 11 rotates in the storage section 1e, the openings 12a, 1 of the switching hole 12 are formed.
2b and 12c selectively coincide with the mouth tubes 1a, 1b and 1c, and the blood path between the pipes 3, 3 and 3 is switched.

A T-shaped cock 1 is provided above the valve body 10.
3 is integrally formed. Each arm of the cock 13 extends in the same direction as the T-shaped switching hole 12. Further, on the upper surface of the cock 13, the openings 12a, 12 of the switching hole 12 are formed.
An arrow mark 14 indicating the directions of b and 12c is formed. In this three-way stopcock, the outer peripheral surface (a) of the switching body 11 of the valve body 10 and the inner peripheral surface (b) of the storage portion 1e of the outer frame 1 serve as sliding portions. The following substance film is formed on at least one surface of the outer peripheral surface (a) and the inner peripheral surface (b) at the sliding portion. In the embodiment of FIG. 1, this film is formed on the outer peripheral surface (a) of the switching body 11, and the film formation region is shown by hatching in FIG.

In the first embodiment, on the outer peripheral surface (a),
A diamond-like carbon (DLC) film is formed. A C _m H _n (hydrocarbon) film is formed as a stabilizing layer on the resin surface of the outer peripheral surface (a) of the switching body 11, and the DLC film has a film thickness of about 500 to 1000 angstroms on the surface of the stabilizing layer. It is formed in. The hydrocarbons are paraffin hydrocarbons, olefinic hydrocarbons or acetylene hydrocarbons, n = 2m + 2, n = 2m or n = 2m-2 (m
Is an integer of 1 or more).

In the three-way stopcock in which the DLC film is formed on the outer peripheral surface of the switching body 11, the coefficient of friction between the outer peripheral surface (a) and the inner peripheral surface (b) of the housing portion 1e does not have the DLC film. It was confirmed that it was reduced to about 1/10 compared with. Also, while flowing the colored fluid through the pipe 3 at various pressures,
An experiment in which the cock 13 was rotated to switch the fluid path was repeated 300 times. As a result, the rotation resistance of the cock 13 did not increase, and the fluid path could be switched smoothly. After switching 300 times, the valve body 10 was removed from the outer frame and the outer peripheral surface of the switching body 11 was observed.
No peeling of the film occurred.

An example of a method for forming a DLC film on the outer peripheral surface (a) of the switching body 11 will be described. Plasma CVD for film formation
(Chemical Vapor Deposition) method. A portion of the valve body 10 other than the outer peripheral surface (a) (hatched portion) of the switching body 11 is masked, and the valve body 1
0 is installed in the film forming chamber. First, argon gas and hydrogen gas are introduced into the film forming chamber, and the hydrogen gas is plasmaized and activated by a magnetron or the like. At this time, the argon gas exerts a function of activating plasma. The surface of the outer peripheral surface (a) of the switching body 11 is activated in this mixed plasma. Subsequently, hydrogen gas and a gas containing a carbon element are introduced into the film forming chamber to form a C _m H _n polymer film on the outer peripheral surface (a) in plasma. Then, to the deposition chamber to increase the introduction amount of the gas containing carbon element, forming a DLC film at 500 to 1000 angstroms thickness on the surface of the C _m H _n stabilizing layer of polymer.

The C _m H _n polymer stabilizing layer functions as an adhesion layer and a buffer layer. Ie C
By providing the _m H _n polymer layer, the adhesion between the resin surface on the outer peripheral surface (a) and the DLC film is enhanced, and by providing the stabilizing layer of the C _m H _n polymer, the resin surface and DL
Mutual diffusion with the C film can be prevented. Therefore, by providing a stabilizing layer of C _m H _n polymer, DLC
It becomes difficult for the film to peel off from the resin surface, and it becomes possible to prevent deterioration of the original physical properties of DLC. The above CV
By the method D, a cubic BN film or a mixed crystal BN film of cubic and hexagonal crystals was formed on the surface of the stabilizing layer of the C _m H _n polymer, and the same characteristics as the DLC film was formed. The three-way stopcock can be manufactured.

Further, as a method for forming a DLC film or a BN film, DC or RF magnetron sputtering method or ECR-CVD (Electron Cyclotron Resonance-C) is used.
VD) method or the like can be used. In addition to the DLC film or BN film, HfN (hafnium nitride), TiN
(Titanium nitride), ZrN (zirconium nitride) or R
eN (however, Re is a rare earth element, for example, Y (yttrium), La (lanthanum), Ce (cerium),
Dy (dysprosium), Eu (europium), Yb
Even if a film of (ytterbium) is formed, the same effect can be obtained. Further, instead of the outer peripheral surface (a) of the switching body 11,
The substance film may be formed on the inner peripheral surface (b) of the housing portion 1e of the outer frame 1.

[0025]

As described above, the blood circuit valve of the present invention is
The sliding property of the sliding part is good, wear of the sliding part is small, and it is possible to switch the blood passage stably with a long life. Since a biocompatible film is formed on the sliding part,
Does not cause adverse effects on the living body. Further, since it is not necessary to use silicone oil, there is no concern about the influence of impurities in silicone oil.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a three-way stopcock as an embodiment of a blood circuit valve of the present invention,

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer frame 1a-1c Mouth tube 1d Step 1e Storage part 2 Male screw part 3 Pipe 4 Connector 10 Valve body 11 Switching body 12 Switching hole 13 Cock (a) (b) Sliding outer peripheral surface and inner peripheral surface

Claims (3)

[Claims] 1. A blood circuit valve installed in a blood circuit for circulating blood from a blood vessel inside the living body to the outside of the living body,
D on the surface of the resin forming the sliding part for circuit switching
A blood circuit valve having an LC (diamond-like carbon) film formed thereon. 2. A blood circuit valve installed in a blood circuit for circulating blood from a blood vessel inside the living body to the outside of the living body,
On the surface of the resin forming the sliding part for circuit switching, B
A nitride film of any one of N, HfN, TiN, ZrN, and ReN (where Re is a rare earth element of Y, La, Ce, Dy, Eu, or Yb) is formed. Blood circuit valve to do. 3. C _m H _n as a stabilizing layer on the surface of the resin
The blood circuit valve according to claim 1, wherein a polymer layer is provided.