JPH042064B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Field of Application> The present invention provides a method for treating a blood flow path by chemical treatment such as acid solution, albumin solution, polyhydroxyethyl methacrylate (hereinafter referred to as PHEMA), discharge treatment such as corona or plasma, or The present invention relates to a hard shell type blood reservoir that has been made hydrophilic through ozone treatment and has improved wettability to blood. <Prior art and its problems> Various polymers have been used in medical equipment materials, but most of them are generally hydrophobic. However, depending on the application, there are many cases in which the surface requires hydrophilic treatment. For example, in open heart surgery, a blood circuit incorporating an artificial lung is used in place of living lungs in order to remove carbon dioxide from the blood and add oxygen to the blood during extracorporeal circulation. In this way, in an extracorporeal blood circulation circuit that incorporates an artificial lung, it is necessary to remove air bubbles if they enter the circuit, or to store blood in case the circulating blood volume decreases due to a break in the circuit tube. A blood reservoir is provided. This blood storage tank is generally a hard shell type blood storage tank made of a hard material because it is easy to check the amount of blood stored and to secure a large amount of blood storage, and it is also easy to integrate with an oxygenator. Therefore, an artificial lung with an integral blood storage tank has also been proposed. However, if such a blood reservoir is hydrophobic,
There was a problem in that the blood and priming liquid did not flow uniformly through the entire blood flow path, and instead flowed into the blood storage part as a biased flow, generating air bubbles. <Problems to be Solved by the Invention> Therefore, an object of the present invention is to improve the wettability for blood and priming liquid by hydrophilizing all or part of the blood flow path surface, and to improve the wettability of blood and priming liquid to flow into the blood storage area. An object of the present invention is to provide a blood storage tank in which the generation of air bubbles due to blood is suppressed. <Means for Solving the Problems> The present invention provides a blood flow path surface that is at least partially inclined, a blood inflow section that is located upstream of the blood flow path surface and has a bottom surface with almost no drop, and a blood flow path surface that is at least partially inclined. A blood storage tank having a blood storage section located below a flow path surface and a blood outflow section located downstream of the blood storage section, wherein the blood flow path surface is hydrophilic and the blood flowing in from the blood inflow section is To provide a blood storage tank characterized in that when blood flows down on a blood flow path surface and flows into a blood storage part, biased flow hardly occurs on the blood flow path surface and the blood flows almost uniformly over the entire blood flow path surface. It is something. Here, it is preferable that the contact angle of the hydrophilic blood flow path surface with water is less than 90°, particularly 80° or less. Below, the blood reservoir of the present invention will be explained in more detail using an oxygenator built-in type blood reservoir as a preferred embodiment. Hard shell type blood storage tank 1 integrated with oxygenator
As schematically shown in FIG. 1, the blood inlet 2,
A blood inflow part 5 that communicates with this blood inlet and has a bottom surface with almost no drop from the blood inlet 2, a blood storage part 6 that communicates with this blood inflow part and has a bottom surface that gradually descends from the blood inflow part 5, and this blood storage. The housing 7 is made of a hard member and has a blood discharge port 3 provided at the bottom of the portion 6. Here, the bottom surface of the blood inflow section 5 and the blood storage section 6
The bottom surface of the housing 7 or the side surface of the housing 7 forms the blood flow path surface 4. A blood reservoir having such a configuration is installed in the extracorporeal circulation circuit of an oxygenator. For example, as shown in FIG. Suitably used. In the preferred embodiment shown in FIG.
The housing has a cylindrical housing main body 12 and mounting covers 13a and 13b that close both open ends of the housing, and inside the housing, a large number of hollow fiber membranes 14 are arranged parallel to each other along the longitudinal direction of the housing. They are spaced apart. Both ends of these hollow fiber membranes 14 are connected to partition walls 15a, 15 with their respective openings not closed.
b is held in a fluid-tight manner by the housing body 12. Further, a gas inflow port 17 is provided in a gas inflow space 16 that communicates with the internal space of the hollow fiber membrane formed by one mounting cover 13a, the housing body 12, and the partition wall 15a, and a gas inflow port 17 is provided in the gas inflow space 16 that communicates with the internal space of the hollow fiber membrane formed by one mounting cover 13a, the housing body 12, and the partition wall 15a. Gas outflow ports 19 are provided in communication with the gas outflow space 18 that communicates with the internal space of the hollow fiber membrane formed by the partition wall 15b. Furthermore, the inner wall of the housing body 12 and both partition walls 15
a, 15b and the outer wall of the hollow fiber membrane 14, the blood chamber 20 has a blood inlet 21 and a blood outlet 2.
2 are provided in communication. The oxygenator 11 shown in this embodiment is of a type in which oxygen-containing gas such as air is blown into the interior space of the hollow fiber membrane 14 and blood is caused to flow outside the hollow fiber membrane 14 to perform gas exchange. The materials used for the hollow fiber membrane 14 include:
Any hydrophobic membrane commonly used in oxygenators may be used, and for example, polytetrafluoroethylene, polypropylene, silicone, etc. are suitable. The blood inlet 2 of the blood reservoir 1 configured as described above with reference to FIG. 1 is fluid-tightly connected to the blood outlet 22 of the artificial lung 11. On the other hand, a heat exchanger 2 is installed at the blood inlet 21 of the oxygenator.
3 is installed. In the heat exchanger 23, a large number of heat exchange tubes 25 are arranged in a casing 24 in parallel and spaced apart from each other along the longitudinal direction of the casing 24, and both ends of the heat exchange tubes 25 are Each opening is held in a liquid-tight manner on the side wall of the casing 24 by a partition wall (not shown) in an unblocked state. A blood inlet port 27 and a blood inlet 21 of the oxygenator 11 communicate with a space 26 formed by this partition wall, the side wall of the casing 24, and the outer wall of the heat exchange tube 25; 26
A water inlet port 28 communicating with the outside of one of the partition walls of the casing 24 and a water inlet port 28 that communicates with the outside of one of the partition walls of the casing 24 are also provided in the internal space of the heat exchange tube 25 that is liquid-tightly separated from the casing 24.
Water outlet ports (not shown) communicating with the outside of the other partition wall of 4 are configured to communicate with each other. Therefore, the heat exchanger 23 shown in this embodiment
Blood flows into the heat exchanger 23 from the blood inlet port 27 and flows outside the heat exchange tube 25, and at this time, hot or cold water flows into the heat exchange tube 25 from the water inlet port 28. , heat exchange tube 15
warms or cools blood that comes into contact with it. However, it is also possible to use a heat exchanger in which blood flows inside the heat exchange tube and a cooling or heating medium flows outside the heat exchange tube. In the present invention, as described with respect to the blood reservoir illustrated in FIG. 1, all or part of the blood flow path surface of the blood reservoir has hydrophilicity. Although the material constituting the blood flow path surface itself may be hydrophilic, examples of materials that have been subjected to hydrophilic treatment are listed below. Although there are various methods for making the blood flow path surface hydrophilic, the following is an example of one that can be applied in the present invention. (1) Acid treatment The acids used include KM _o O ₄ /H ₂ SO ₄ solution,
There are solutions such as K ₂ Cr ₂ O ₇ /H ₂ SO ₄ , but especially
A KM _o O ₄ /H ₂ SO ₄ solution is preferred. The concentration of each component in this solution is KM _o O ₄ 0.05-1wt%,
90 to 100 wt% of H ₂ SO ₄ is preferred for hydrophilization. Furthermore, the acid mixture is not limited to the above-mentioned mixed acids, and a single acid such as H ₂ SO ₄ alone may be used. (2) Albumin aqueous solution treatment It is suitable for hydrophilization to use an albumin aqueous solution of 0.5 to 8 w/v%. (3) PHEMA treatment Treatment is performed using PHEMA, that is, polyhydroxyethyl methacrylate, and its concentration is preferably 0.05 to 4 wt% for hydrophilization. (4) Corona discharge treatment Corona discharge treatment is a method of causing so-called corona discharge on a material and introducing hydrophilic groups to the surface, and the treatment time is determined depending on the degree of hydrophilization required. (5) Plasma treatment Plasma treatment is a method of treating the surface of a polymer using active species created by glow discharge, and the treatment time is determined depending on the degree of hydrophilization required. (6) Ozone treatment Ozone treatment is a method of introducing hydrophilic functional groups onto the surface by applying ozone to the surface. The treatment time is determined depending on the required degree of hydrophilization. As described above, there are various methods for making a blood reservoir hydrophilic, but the easiest way to evaluate the degree of hydrophilicity is to evaluate the wettability to water, that is, the contact angle with water. At this time, if the contact angle with water of the constituent members of the blood reservoir is set to less than 90°, preferably 80° or less, wettability with respect to the priming liquid and blood is sufficient. <Operation of the invention> In an oxygenator device in which a blood storage tank 1 is integrated with an oxygenator 11 and a heat exchanger as shown in FIG. The blood that is heated or cooled while reaching the blood inlet 21 of the artificial lung 11 flows through the inner space of the hollow fiber membrane 14 via the hollow fiber membrane 14 while passing through the blood chamber 20. gas exchange with oxygen-containing gas, removing carbon dioxide from the blood and supplying the oxygen consumed by itself. The blood supplied with oxygen in this manner flows out from the blood outlet 22 of the artificial lung 11 and flows into the blood reservoir 1 from the blood inlet 2 of the blood reservoir 1 which is in communication with it. The blood introduced from the blood inlet 2 is communicated with the blood inlet 2, reaches the blood inlet 5 which has a bottom surface with almost no drop, is smoothly sent through the blood flow path surface 4, and quietly flows into the blood storage part 6. It flows down into the interior and is stored. Conventionally, the housing 7 of the blood reservoir 1 has been made of a hydrophobic material such as hard vinyl chloride resin, styrene resin, carbonate resin, or the like. Therefore, since the blood flow path surface 4 also has hydrophobicity, when bloodless priming is performed, the priming liquid does not flow across the entire blood flow path surface 4, but flows unevenly, causing turbulence in the liquid flow.
The priming liquid flows into the blood storage part 6 like a waterfall falling into a pond, and the priming liquid has the disadvantage of generating bubbles in the blood storage part 6. In the present invention, the blood flow path surface 4 of the blood reservoir 1 explained with reference to FIG. The priming liquid flows unevenly on the blood flow path surface 4,
Since the fluid does not flow all at once and forms a homogeneous flow as a whole, there is no possibility of foaming. <Examples> The present invention will be specifically described below based on Examples. Comparative Example A blood reservoir as shown in FIG. 1 was manufactured by injection molding of polycarbonate resin. Example 1 The blood flow path surface of a blood reservoir prepared in the same manner as in Comparative Example was immersed in a 0.4% KMnO ₄ /concH ₂ SO ₄ solution for 5 minutes, the internal fluid was drained, the tank was washed with water, and then air-dried. Example 2 An artificial lung prepared in the same manner as in the comparative example was filled with a 4% albumin solution and left to stand for 30 seconds. Thereafter, after draining the internal solution, it was air-dried in a clean bench. Example 3 A blood reservoir prepared in the same manner as the comparative example was charged with 0.2w/v.
Fill with methanol solution containing % PHEMA;
It was left standing for 1 minute. Thereafter, the internal solution was drained, and then air-dried in a clean bench. Example 4 The blood flow path surface of the blood reservoir prepared in the comparative example was treated using a corona discharge device (HFS202, manufactured by Kasuga Electric Co., Ltd.).
Width 10 wrapped with a single Teflon sheet with a thickness of 80μm
Corona discharge treatment was performed by passing a current of 120 V and 6.5 A through an electrode with a length of 20 mm and a length of 20 mm. Example 5 The blood reservoir prepared in the comparative example was placed in a tank,
Plasma treatment was performed at 10 ^-1 torr, 30 to 40°C, and 100 W for 2 min. Example 6 The blood reservoir prepared in the comparative example was placed in a glass desiccator, and the temperature inside the desiccator was raised to 50°C.
Flow 0.8/min O ₂ into the ozone generator and 100V
ozone was generated and flowed into the desiccator. After performing this process for 20 minutes, clean the inside of the desiccator.
After replacing with _O2 , it was taken out from the desiccator and the ozone treatment was completed. Test Example 1 A part of the blood flow path surface of the blood reservoirs prepared in Comparative Example and Examples 1 to 6 was cut out and the contact angle with water was measured, and the results shown in Table 1 were obtained.

[Table] Test Example 2 Regarding the blood storage tanks prepared in Comparative Examples and Examples 1 to 6, with 300 ml of physiological saline stored in the blood storage part, 4/4 of the same physiological saline was poured onto the blood flow path surface.
The saline was allowed to flow for 10 minutes, and the flow of the physiological saline on the blood flow path surface and the generation of bubbles at the blood storage area were observed. The results are shown in Table 2.

[Table] <Effects of the Invention> The blood reservoir of the present invention has extremely good wettability with respect to the priming liquid and blood, especially since the blood flow path surface has hydrophilicity. Therefore, the blood flowing through the blood flow path surface including the blood inflow section having a bottom surface with almost no drop does not flow unevenly and flows down uniformly, so that air bubbles are prevented when blood flows from the blood flow path surface into the blood storage section. The occurrence can be suppressed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a blood storage tank applied to the present invention and a conventional example. FIG. 2 is a partially cutaway front view showing an artificial lung device having a hollow fiber membrane applied to the present invention. Explanation of symbols, 1...Blood storage tank, 2...Blood inlet, 3...Blood outlet, 4...Blood flow path surface (blood contact surface), 5...Blood inflow part, 6...Blood storage part, 1
1... Artificial lung, 14... Hollow fiber membrane, 14a... Hollow fiber membrane outer wall (blood contact surface), 16... Gas inflow space, 17... Gas inflow port, 18... Gas outflow space, 19... Gas outflow port, 20...Blood chamber, 21...Blood inlet, 22...Blood outlet,
23... Heat exchanger, 25... Heat exchange tube, 27
...Blood inlet port, 28...Water inlet port.

Claims (1)

[Scope of Claims] 1. A blood flow path surface at least partially inclined, a blood inflow section located upstream of the blood flow path surface and having a bottom surface with almost no drop, and a blood flow path located below the blood flow path surface. A blood storage tank having a blood storage part and a blood outflow part located downstream of the blood storage part, wherein the blood flow path surface is hydrophilic, and blood flowing from the blood inflow part flows down on the blood flow path surface. 1. A blood storage tank characterized in that when blood flows into a blood storage part, biased flow hardly occurs on a blood flow path surface and the blood flows almost uniformly over the entire blood flow path surface. 2. The blood reservoir according to claim 1, wherein the hydrophilic blood flow path surface has a contact angle with water of less than 90°. 3. The blood reservoir according to claim 2, wherein the contact angle is 80° or less.