METHOD OF DISPOSAL OF WASTE FLUID CONTAINING BODY FLUID AND TREATMENT TANK THEREFOR

Abstract: This invention relates to the disposal of a waste fluid containing a body fluid, such as blood and lymph, and provides a method of disposing of a waste fluid containing a body fluid by which a treatment tank can be transported easily after the collection of a waste fluid and the waste fluid can be incinerated together with the tank with ease, and a treatment tank suitably used therefor. The disposal method comprises the steps of collecting a waste fluid which contains a body fluid and a coelom washing fluid in a reservoir (2) made from a synthetic resin by sucking the former into the latter, removing water contained in the waste fluid through a filter (17) capable of separating contagious micro-organisms and thereafter discarding the tank (2), which contains the contagious micro-organisms in the waste fluid, together with the filter (17). The treatment tank according to the present invention used suitably to practice this method consists of a treatment tank (1) for a waste fluid containing a waste fluid, which tank is composed of a reservoir (2) made from a synthetic resin for storing the waste fluid therein and both of a waste fluid feed pipe (7) and a vent (8) provided therein, the reservoir (2) being provided with filter (17) capable of separating contagious micro-organisms, a pipe (12) for discharging the water in the waste fluid which has passed through the filter (17), and a valve (14) in the discharge pipe (12).

Description: The present invention relates to methods of and containers for treating a body fluid such as blood and lymph generated during medical treatment or surgery for injury and disease, a physiological saline solution after washing the operated part and the oral cavity, and a waste liquid containing a body fluid such as urine and stool. A waste liquid containing a body fluid released from a patient during surgery and medical treatment (hereinafter, the wording "waste liquid" means the infectious liquid containing a body fluid ) is aspirated and collected in a collecting bottle with an applied negative pressure. After that, the waste liquid is flushed down the drain. For this purpose, a glass bottle (the capacity of which is in the rage of 5 to 8 liters) is used. This bottle is, however, heavy, and is cumbersome in discarding the hazardous waste liquid. Moreover, from a point of view of environmental protection, medical waste should be sterilized before being returned to environment. Under process of autoclave sterilization, the waste liquid containing the body fluid emits an offensive smell. Germicidal agent becomes ineffective in the presence of highly concentrated organic matter such as blood cells and fat. Thus, in recent years, the trend is toward one-way containers made of synthetic resin. The one-way container can be incinerated together with the waste liquid. A disposal container is disclosed in US-A-3,685,517 such as a treating container 55 as shown in Fig. 6, wherein a synthetic resin made bag member 54 is welded to a firm synthetic resin made cover 53 with an outlet 51 and an inlet 52. This container 55 is used in such a manner that the bag member 54 is inserted in a firm pressure reducing vessel 56 and the upper cover 53 is air-tightly fitted to the opening of the pressure reducing vessel 56. The upper cover 53 has a first through-hole 57 and a second through-hole 58. The first through-hole 57 communicates with the space between the inner surface of the pressure reducing vessel 56 and the outer surface of the bag member 54, whereas the second through-hole 58 communicates with a conduit 59 projectingly provided in the bag member 54. When the outlet 51 is connected to a pressure reducing source, the bag member 54 is swelled in the pressure reducing vessel and concurrently the waste liquid is aspirated through the inlet 52. Using the one-way container eliminates the troublesome works such as a work for discarding the waste liquid and a work for washing the interior of the bottle after discarding the waste liquid. The prior art container, however, has the following disadvantage: namely, although the container itself is extremely reduced in its weight by changing the material thereof from glass to synthetic, the container filled with the waste liquid is still heavy because the content therein is mainly composed of water. This takes a lot of labor in its transport and requires a large amount of energy in its incineration. In view of the above situation, the present invention has been made. Accordingly, an object of the present invention is to provide a method for treating a waste liquid containing a body fluid, which makes easy the transport of the container and subsequent incineration and a container suitable for carrying out the method. A method of the present invention comprises the steps of: sucking and collecting a waste liquid containing a body fluid or a washing liquid for the body cavity in a synthetic resin made storage container; removing the water content in the waste liquid through a filter to separate infectious microbes; and discarding the storage container containing the infectious microbes in the waste liquid together with the filter. The treating container of the present invention suitable for carrying out the method mentioned above is composed of a synthetic resin made storage container which is provided with an inlet and an outlet. The storage container is further equipped with a filter to separate infectious microbes and a discharge tube for discharging the water content in the waste liquid passing through the filter, the discharge tube being provided with a valve for opening/closing the discharge tube. Preferably, the filter is constituted of a secondary filter capable of separating the infectious microbes and a primary filter for preventing the blocking of the secondary filter. Further, the filter is preferably provided at such a position as to project from the inner surface of the storage container toward the inside thereof. The storage container is preferably capable of expansion and contraction. According to the present invention, the waste liquid after being sucked and collected in the storage container is treated such that the water content therein is discharged from the discharge tube to the outside through the filter by opening of the valve. The filter is able to separate the infectious microbes, and hence to enclose bacteria and the like harmful to a human body in the storage container together with organic matter such as fat, blood corpuscles and the like. In this case, by pressurizing the waste liquid in the treating container and sucking the flow-out side of the discharge tube, it is possible to increase the filtration rate. In addition, since the filter is constituted of the secondary filter capable of separating the infectious microbes and the primary filter separating bigger particulates and preventing the blocking of the secondary filter, it is possible to increase the filtration efficiency. Further, by providing the filter at such a position as to project from the inner surface of the storage container toward the inside thereof, it is possible to prevent solid components which has high specific gravity in the body fluid such as blood clot from adhering on the surface of the filter membrane in a covering manner. The storage container after the water content in the waste liquid is removed is made light, and is easily incinerated. Even if the filter cannot separate the smallest infectious microbes such as viruses from the water content, the water content can easily be sterilized by adding germicidal agent or applying heat, because almost all organic matter and fat have been removed from the water content. In this case, the storage container is incinerated together with the filter, which eliminates the hazard of leaking the infectious microbes to the outside. By making the storage container expandable and contractible, it is possible to make smaller the capacity of the treating container before and after the usage, which is convenient for the storage and transport thereof. Namely, according to the present invention, the waste liquid containing the body fluid is sucked and collected in the treating container, and then filtered by the filter provided in the treating container for discharging the water content in the waste liquid to the outside, it is possible to make light the treating container, and to make easy its incineration, and to make easy sterilization of the water content if necessary. In addition, the filter is constituted of the primary filter and the secondary filter. The primary filter makes it possible to prevent the secondary filter with micro pores from being clogged quickly, and hence to prevent the lowering of the filtration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of a treating container according to an embodiment which is accommodated in a pressure reducing vessel; Fig. 2 is a partially sectional view of the vicinity of a base plate of a hollow fibrous membrane constituting a secondary filter; Fig. 3 is a partially sectional view showing the structure of a primary filter; Fig. 4 is a partially sectional view showing a filtering state of the treating container according to the embodiment; Fig. 5 is a sectional view of a treating container according to another embodiment; and Fig. 6 is a sectional view of a conventional treating container accommodated in a pressure reducing vessel. Fig. 1 shows a treating container 1 and its auxiliary equipment according to an embodiment. The treating container 1 includes a vertically expandable storage container 2. The storage container 2 is constituted of an upper cover 3, a lower cover 4, and a cylindrical side wall portion 5 for connecting both the covers 3 and 4. The side wall portion 5 has a vertically expandable and contractible bellows-like structure, or is made by folding of a flexible synthetic resin sheet. The upper cover 3 and the lower cover 4 are made of relatively firm synthetic resin. The upper end of the side wall portion 5 is fixed on the lower surface of the upper cover 3 while the lower end of the side wall portion 5 is fixed on the peripheral edge of the lower cover 4, each being fixed by welding or adhering. The above synthetic resin comprises a thermoplastic resin having a good formability and a transparent or semitransparent property such as polyvinylchloride, polypropylene and polyethylene. In addition, the side wall portion 5 and the lower cover 4 of the storage container 2 are accommodated in a firm pressure reducing vessel 71 in collection of a waste liquid. The upper cover 3 is formed integrally with an outlet 8 and an inlet 7 which are communicated with the interior of the treating container. On the lower portion of the peripheral edge of the upper cover 3, a recessed groove 9 is provided to be air-tightly snap-fitted around the peripheral edge of the upper edge of the pressure reducing vessel 71. A handle 10, which is used in taking out the treating container 1 from the pressure reducing vessel 71 and in transporting the container, is formed on the upper surface of the upper cover 3. The pressure reducing vessel 71 mentioned above is repeatedly used, and which is formed of a transparent or semitransparent glass or synthetic resin. The pressure reducing vessel 71 has a lower portion 72 on which an exhaust tube 73 is provided. A discharge tube 12 is formed at the center of the lower cover 4. A valve 14 for closing/opening the discharge tube 12 is mounted in an upper conduit 13 of the discharge tube 12. A short cylindrical supporting member 15 is formed on the upper portion of the lower cover 4 so as to project to the inside and to surround the opening of the discharge tube 12. A filter unit 17 is liquid-tightly fixed on the supporting member 15 by welding or adhering. The filter unit 17 is constituted of a base plate 18 fixed on the upper edge of the supporting member 15, a secondary filter 20 composed of a group of hollow fibrous membrane 19 planted on the base plate 18 in a reversed U-shape, and a primary filter 21 for preventing the blocking of the secondary filter 20. The primary filter 21 is fixed on the peripheral edge of the upper portion of the base plate 18 so as to surround the secondary filter 20. Fig. 2 is an example of an enlarged view of the each hollow fibrous membrane 19 constituting the secondary filter 20. The membrane 19 has many micro-openings (pores) 23 communicated with the hollow portion 22, and is fixed at its end on the base plate 18. The membrane 19 is suitable for this embodiment because the total filtration area of the filter can easily be enlarged by simply increasing the number of the fibers. Preferably, samples of materials for the membrane 19 include known hydrophobic synthetic resins such as polyethylene, polypropylene, polysulfone, polyamide and the like, which are subjected to hydrophilic treatment; or hydrophilic synthetic resin. The pore size of the membrane 19 must be made small enough to separate infectious microbes. The typical size of the infectious microbes such as bacteria and blood cells is bigger than 1 µm in size, and accordingly, the pore size should be in the range of from 0.5 to 0.1 µm. The smallest infectious microbes, viruses are usually 0.02 to 0.4 µm in size or even smaller, thus the pore size of about 0.01 µm is required for directly separating the viruses. However, the viruses require other organic cells such as microbes or blood cells as the parasitic hosts for their survival, and these particulates are bigger than 1 µm in size. Moreover, the waste liquid containing only the small infectious microbes such as viruses can easily be sterilized by autoclave sterilization or germicidal agent sterilization, because most organic matter have been removed from the waste liquid. Therefore, the secondary filter 20 capable of separating bacteria is sufficient for practical purposes. The total filtration area required of the secondary filter 20 is dependent on the total capacity of the stored waste liquid in the treating container 1; for example, it should be approximately 0.5 m 2 for 5 liter of the waste liquid. In addition, as for the hollow fibrous membrane 19 planted on the base plate 18, many types are commercially available, for example, STERAPORE by Mitsubishi Rayon Co., Ltd.. On the other hand, as shown in Fig. 3, the primary filter 21 has such a structure that a sheet filter 25 such as a paper filter or a non-woven fabric filter is sandwiched between two plates 24, 24. The pressing plate 24 has many through-holes 26, each of which has a diameter of about several mm. The pore size of the primary filter 21, should be about 10 µm or bigger. The primary filter can prevent relatively larger particulates such as high protein, fat from blocking of the secondary filter 20. For collecting a waste liquid by using the above-mentioned treating container 1, first, in such a state as to close the valve 14 of the discharge tube 12, the portion of the treating container 1 is inserted in the pressure reducing vessel 71, and the upper cover 3 is air-tightly fitted around the upper edge of the pressure reducing vessel 71. The outlet 8 for the upper cover 3 and the opening 73 of the pressure reducing vessel 71 are connected to a pressure reducing source such as a vacuum pump, and a suction tube is connected to the inlet 7. The value of the gauge pressure of the pressure reducing source is generally about -0,53 bar (-400mmHg). Since the suction tube communicates with the atmosphere, the value of the pressure in the treating container 1 is slightly larger than that of the space between the pressure reducing vessel 71, and the treating container 1. Consequently, the side wall portion 5 of the treating container 1 is expanded to be swelled largely. After completion of the collection of the waste liquid, the connection tubes connected to the suction tube and the pressure reducing tube are removed from the inlet 7 and the outlet 8 respectively and caps 40 (see Fig. 4) are mounted on the outlet 8 and the inlet 7. By holding the handle 10, the treating container 1 is pulled out of the pressure reducing vessel 71, and is mounted on a tank 76 through a supporting base 75 as shown in Fig. 4. At this time, the leading edge of the discharge tube 12 is inserted in an insertion port 77 of the tank 76. Subsequently, by opening the valve 14, the waste liquid in the treating container 1 is filtered by the filter unit 17, and the water content, in which most organic matter have been eliminated, is allowed to flow in the tank 76. At this time, in order to increase the filtration rate, the treating container 1 may be pressed in the direction of contracting the bellows of the side wall portion 5, or a suction port 78 provided on the tank 76 may be connected to the pressure reducing source. Further, the pressurized air may be fed in the treating container 1 through the outlet 8 of the treating container 1. When the filtration is completed, the treating container 1 is removed from the tank 76 after the valve 14 is closed. The content left inside the treating container 1 is mainly composed of solid components such as organic matters and cells, so that the treating container 1 is made light to be transported and is easily incinerated by using an incinerator with a relatively small amount of energy. Finally, sterilization of the liquid drained in the tank 76 may be done by adding germicidal agent or applying heat to the liquid. In addition, reference numeral 79 indicates a drain port of the tank 76, and is fitted with a cap 80. According to the embodiment mentioned above, the treating container 1 has the side wall portion 5 of the storage container 2 which is made to be of a bellows-like structure or made by folding of a flexible sheet. However, as shown in Fig. 5, the side wall portion 5A may be formed of a cylindrical body. In addition, reference numeral 30 indicates a supporting base for preventing the breakage of the discharge tube 12, wherein the upper edge thereof is snap-fitted around the outer peripheral edge of the lower cover 4, and part of the side wall is cut-out for making easy the operation of the valve 14. In the embodiment as shown in Fig. 1, hollow fibrous membrane 19 is used as the secondary filter 20 of the filter unit 17; however, other types of filters are of course used. The primary filter 21 does not necessarily have a laminated structure as in this embodiment; for example, it may be a type in which a non-woven fabric filter is formed in a cap shape. Further, the exhaust tube 73 is not necessarily provided on the lower portion of the pressure reducing vessel 71, and the space between the inner surface of the pressure reducing vessel 71 and the side wall portion 5 of the treating container 1 or the outer surface of the lower cover 4 may be in the pressure-reducing state by some means; for example, as in the prior art, a passage communicated between the outlet 8 and the above space may be provided on the upper cover 3. The present invention is excellent in handling and safety, and further useful as a method of and a container. for treating infectious liquid such as blood and lymph generated during medical treatment or surgery for injury and disease, a physiological saline solution after washing the operated part and the inside of the body, and infectious liquid containing a body fluid such as urine and stool.

Claims: A method of treating a waste liquid containing a body fluid comprising the steps of: sucking and collecting a waste liquid containing a body fluid or a washing liquid for the body cavity in a synthetic resin made storage container (2); characterized by the following steps: removing a water content in said waste liquid through a filter (17) to separate infectious microbes; and discarding said storage container (2) containing the infectious microbes in said waste liquid together with said filter (17). The method of treating a waste liquid containing a body fluid according to claim 1, wherein said filter (17) comprises a secondary filter (20) capable of separating infectious microbes and a primary filter (21) for preventing the blocking of said secondary filter (20). The method of treating a waste liquid containing a body fluid according to claim 2, wherein a filter capable of separating bacteria is used as said secondary filter (20). The method of treating a waste liquid containing a body fluid according to claim 2, wherein a filter capable of separating virus is used as said secondary filter (20). The method of treating a waste liquid containing a body fluid according to claim 1, wherein the step of filtering includes pressurizing the interior of said storage container (2) or sucking a discharge side of said filter (17). The method of treating a waste liquid containing a body fluid according to claim 2, wherein the step of filtering includes pressurizing the interior of said storage container (2) or sucking a discharge side of said filter (17). A container for carrying out the method of treating a waste liquid containing a body liquid according to claim 1 comprising: a synthetic resin made storage container (2) for storing a waste liquid containing a body fluid, which is provided with an inlet (7) and an outlet (8); characterized in that said storage container (2) includes a filter (17) to separate infectious microbes and a discharge tube (12) for discharging a water content in the waste liquid after passing through said filter (17), said discharge tube (2) being provided with a valve (14) for opening/closing said discharge tube (2). The container for treating a waste liquid containing a body fluid according to claim 7, wherein said filter (17) includes a secondary filter (20) capable of separating infectious microbes and a primary filter (21) for preventing the blocking of said secondary filter (20). The container for treating a waste liquid containing a body fluid according to claim 8, wherein a filter capable of separating bacteria is used as said secondary filter (20). The container for treating a waste liquid containing a body fluid according to claim 8, wherein a filter capable of separating viruses is used as said secondary filter (20). The container for treating a waste liquid containing a body fluid according to claim 7, wherein said filter (17) is provided at such a position as to project from an inner surface of said storage container (2) toward an inside thereof. The container for treating a waste liquid containing a body fluid according to claim 8, wherein said filter (17) is provided at such a position as to project from an inner surface of said storage container (2) toward an inside thereof. The container for treating a waste liquid containing a body fluid according to claim 7, wherein said storage container (2) is formed to be expandable and contractible. The container for treating a waste liquid containing a body fluid according to claim 7, wherein said storage container (2) is formed of a synthetic resin made flexible sheet in a bag shape. The container for treating a waste liquid containing a body fluid according to claim 11, wherein a filter capable of separating bacteria is used as said secondary filter (20). The container for treating a waste liquid containing a body fluid according to claim 12, wherein a filter capable of separating bacteria is used as said secondary filter (20).

Inventors: YAMADA KEIICHI, YAMADA, KEIICHI                                TD., YAMADA, KEIICHI, GENERAL LAB., DAIKEN IKI CO. LTD.
Applicants: DAIKEN IKI CO LTD, DAIKEN IKI CO. LTD.
Application year: 1993
Main classification: A61L11
IPC codes: A61L11, A61G12, A61M1