Shaped filter with virus barrier properties for use in medical aspirator systems

Abstract

A composite filter that constitutes a shaped filter according to the present invention, which is for use in a flexible disposable bag that is produced so as to aspirate a secreted material or the like in the body of a patient, store the secreted material or the like therein, and be discarded when a certain storage amount is reached, has a bottomed cylindrical shape, has a structure such that an outer layer constituting an outside part is integrated with an inner layer constituting an inner part, and is configured such that internal exhaled breath passes through the inner layer after passing through the outer layer. The outer layer is formed of a multilayer non-woven fabric that has at least two layers including a non-woven fabric and a charged non-woven fabric or at least three layers including a non-woven fabric, a porous PTFE, and a charged non-woven fabric, wherein the charged non-woven fabric is disposed on the downstream side of the internal exhalated breath relative to the non-woven fabric. The inner layer is formed of a sintered product of a polyethylene or polypropylene that has sodium carboxymethyl cellulose or sodium polyacrylate carried thereon, the porous PTFE prevents wetting of the charged non-woven fabric, and the non-woven fabric contains nano zinc oxide and inactivates viruses.

Description

Virus barrier molded filters for medical suction systems

[0001] The present invention relates to a molded filter attached to a disposable bag in a medical suction system, which exhausts the patient's exhaled breath through a flexible bag, and simultaneously aspirates and stores bodily secretions and waste fluids such as saline and blood, and discards the bag itself when a certain amount of storage is reached.

[0002] In recent years, an increasing number of medical suction systems use disposable bags as components. These bags are flexible bags made of plastic film that suck in and store the patient's exhaled breath, bodily secretions, and waste fluids such as saline and blood (hereinafter referred to as "bodily secretions, etc."). The bags are then discarded when a certain amount is stored. These disposable bags require a suction port, which introduces the exhaled breath and bodily secretions into the bag, and an opening, i.e., an exhaust port, for discharging the air in the bag into a rigid container outside the bag.

[0003] Furthermore, the exhaust opening requires a filter that is breathable to transmit the suction force (negative pressure) from the external suction pump to the suction catheter inserted into the patient's body, and is also waterproof to prevent suctioned bodily secretions from seeping out of the opening into the suction pump. To fulfill these two requirements, cylindrical molded products made primarily of sintered high-molecular-weight polyethylene (PE) with sodium carboxymethylcellulose (CMC) (hereinafter referred to as "CMC-PE sintered filter"), i.e., molded products made from two different materials, have traditionally been used to block the exhaust port as breathable and waterproof filters (Patent Document 1).

[0004] First, a basic system of a general-purpose medical suction device currently in use will be briefly described. A basic system 100 is typically configured as shown in Figure 1. (1) A disposable bag or container 110 (hereinafter referred to as a "disposable bag") made of flexible plastic, which is equipped with an inlet 11 for connecting a suction catheter 18 for suctioning bodily secretions of a patient or the like, and an outlet 13 for discharging air from the bag through a filter 12 while preventing water leakage, and is configured to store bodily secretions of a patient or the like in the bag. (2) A rigid container body 120 with a lid that stores the disposable bag 110 and has an outlet 15 / suction port 16 for reducing the pressure inside the bag. (3) A suction device body 130 that generates suction force using an electric motor. (4) A suction port (described below) that transmits the suction force to the catheter 18. (5) A connecting hose 19 that connects the rigid container body 120 and the suction device body 130, and a joint for attaching the hose (not shown).

[0005] The basic system 100 employs a so-called bypass exhaust method in which a disposable bag 110 (1) is stored inside a rigid container body 120 (2), and the exhaust port 13 of the bag is not directly connected to the suction port 16 on the aspirator body 130 (3). Instead, the exhaust port 15 of the rigid container is connected to the suction port 16 on the aspirator body, and the rigid container is depressurized to exhaust air from the exhaust port 13 of the disposable bag. This is because the bag expands under reduced pressure, making it easy to store bodily secretions and the like, and also because the suction bag is easy to remove. Also, even if bodily secretions and the like in the bag leak from the filter 12, they are stored in the rigid container and are not directly absorbed by the suction mechanism on the main body.

[0006] The mechanism for aspirating secretions from the patient's body into a disposable bag is as follows: First, the aspirator main body 130 aspirates the air inside the rigid container through the outlet 15 of the rigid container main body 120, typically at 20 to 35 kPa, creating a reduced pressure inside the rigid container. As a result, the disposable bag 110 stored inside the rigid container expands due to the air pressure difference, and at the same time, the air inside the disposable bag is expelled from the exhaust port 13 of the disposable bag 110 via the filter 12 attached to the bag. As a result, a suction force is generated in the bag 110, which causes the patient's body secretions and the like to be aspirated into the disposable bag 110 through the suction catheter 18.

[0007] Incidentally, since the disposable bag 110 is stored inside the rigid container body 120 and the suction port 16 on the aspirator body side is connected to the exhaust port 15 of the rigid container, when the breathable waterproof filter 12 of the disposable bag 110 is attached to the bag, it is possible to attach it from the outside of the bag so as to block the exhaust port, i.e., to attach it externally. However, when attempting to store the disposable bag 110 equipped with the breathable waterproof filter 12 as efficiently as possible inside the rigid container body 120, it is usually more efficient to attach this breathable waterproof filter 12 inside the bag.

[0008] In the example of the basic system in Figure 1, a plastic (polypropylene: PP) molded product equipped with a pair of suction and exhaust ports is fitted with a cylindrical filter with a bottom made mainly of CMC / PE sintered compact, blocking the exhaust port, and this molded product is then attached to the inside of a flexible plastic bag by heat sealing. This built-in method is considered rational in terms of maximizing the capacity of the disposable bag and reducing the cost of bag formation.

[0009] The only breathable and waterproof filter in a medical suction system is usually a primary filter built into the disposable bag, but in some cases, a secondary filter is installed behind the disposable bag to complement the primary filter in order to prevent mist from bodily secretions and other substances from passing through the primary filter and contaminating the suction pump. For example, Patent Document 2 discloses an example in which an independent filter component is used in a connecting hose connecting the suction bottle (rigid container) to the suction device main body downstream of the exhaust port of the waste bag.

[0010] The primary filter of the disposable bag must have the following three functions: (1) breathability against exhaust air, in order to transmit the suction force (negative pressure) from the suction pump to the suction catheter inserted into the patient's body; (2) waterproofness, in order to prevent bodily secretions and the like sucked through the suction catheter from filtering out through the exhaust port to the suction pump; and (3) pathogen barrier properties, in order to prevent bacteria and viruses (hereinafter referred to as "pathogens") contained in the exhaled air from filtering out of the disposable bag when ventilation occurs.

[0011] However, until now, attention has focused primarily on efficiently achieving both (1) breathability and (2) waterproofness, which are the minimum functions required for the entire medical suction system to operate. As for (3) pathogen barrier properties, they have been left unresolved due to the extremely high technical difficulty involved, and there has been little discussion of pathogen barrier properties, particularly for exhaled breath. However, since the outbreak of the COVID-19 pandemic, it has become recognized that the release of these pathogens from a patient's exhaled breath into the surrounding environment poses an extremely significant risk. Therefore, pathogen barrier properties have become an important issue that must be addressed beyond the breathability and waterproofness of filters.

[0012] The pathogen barrier properties of the breathable / waterproof filter include two types: a barrier against exhaled breath and a barrier against leakage of bodily secretions, etc., from the breathable / waterproof filter, as described above. The filter's pathogen barrier properties do not simply require the removal of pathogens contained in exhaled breath and bodily secretions, etc., released from the body when the air is exhausted through the filter 12. The disposable bag 110 stores aspirated bodily secretions, etc., within the bag and is discarded when a predetermined amount is reached. During disposal, it is necessary to prevent bodily secretions, etc., aspirated and stored within the bag from leaking through the filter 12 and the exhaust port 13, contaminating the interior of the rigid container body 120 and adversely affecting the suction mechanism of the inhaler body 130. Furthermore, even if bodily secretions, etc., leak from the filter 12, the filter 12 must still have pathogen barrier properties, as described above.

[0013] Thus, in disposable bags for medical suction systems, the filters (molded bodies) built into or attached to them must simultaneously satisfy three functions that are difficult to achieve simultaneously: breathability, waterproofness, and pathogen barrier properties. It is difficult to manufacture a filter that must satisfy all three functions using a single material, so initially, a CMC / PE sintered filter was proposed, which combined two materials, namely a molded polymer and another polymer swelling material, to provide breathability and waterproofness, respectively.

[0014] This filter is made by mixing powdered CMC into a porous sintered compact of polyethylene (PE) formed into the desired shape by heat-sealing small particle sizes. The breathability is achieved by utilizing the numerous pores in the sintered PE, while the waterproofing is achieved by the CMC, present in powder form in the numerous openings in the sintered PE. Upon contact with liquid bodily secretions, the CMC rapidly expands and blocks the pores of the sintered PE. The most commonly used type of PE is high-density polyethylene (HD PE), including ultra-high molecular weight polyethylene (UHMW PE). These CMC-PE sintered filters remain widely used as a core product due to their relatively low production cost and excellent instantaneous waterproofing.

[0015] In recent years, in addition to CMC / PE sintered compact filters, filters that use sodium polyacrylate (PAS) powder or a CMC / PAS mixed powder instead of CMC powder, or polypropylene (PP) sintered compacts with CMC powder, PAS powder, or a CMC / PAS mixed powder instead of PE sintered compacts have also been used. While these do not combine functions other than breathable waterproof filters, they are used for reasons such as ease of use in other applications and economic advantages. The characteristics of these filter materials are summarized in Table 1 below. In the following, these CMC / PE sintered compact replacement types will be referred to as "CMC / PE sintered compacts (filters, etc.)."

[0016] (Table 1) Combinations of sintered materials and supporting materials and their performance

[0017] *HDPE: High-density polyethylene

[0018] The pathogen barrier properties of filters against internal exhaled air are generally assessed using the bacterial aerosol removal rate (bacterial droplet collection efficiency test, JIS L1912) and the viral droplet collection efficiency test (JIS L1912-compliant). On the other hand, no established indicators exist for pathogen barrier properties when liquids leak from the filter. However, it is clear that the size of the pathogen and the pore size of the PE sintered compact are crucial in both cases. Generally, bacteria range in size from 0.8 (Staphylococcus aureus) to 10 μm, and viruses range in size from 0.02 to 1.0 μm, while the pore size of PE sintered compacts is generally 5 to 60 μm. Due to limitations in sintering technology and the need to ensure a certain level of breathability, it is difficult to reduce the pore size to 5 μm or less. Therefore, even if a PE sintered compact filter is publicly purported to exhibit high barrier properties in the bacterial aerosol removal rate test, it is generally considered that it does not inherently provide a barrier function against bacteria and viruses (pathogens) by itself.

[0019] Furthermore, with regard to waterproofing, CMC-PE sintered filters have a major shortcoming, as will be described in detail below. There are two aspects to the waterproofing required of disposable bags. The first aspect is instantaneous waterproofing. It is necessary to prevent the filter from being submerged in bodily secretions during suction, causing momentary leakage of mist or liquid bodily secretions from the filter, passing through the exhaust port into the rigid container, and even contaminating or adversely affecting the suction mechanism inside the suction device itself.

[0020] The second aspect of CMC-PE sintered filters is their fundamental lack of long-term waterproofing. This is due to the water-solubility of CMC, which provides the waterproofing function. When a CMC-PE sintered filter is immersed in tap water for approximately 24 hours, a significant amount of dissolved CMC is easily observed leaching out. This phenomenon allows bodily secretions, along with the dissolved CMC, to easily leak out of the disposable bag's outlet, causing serious problems for the environment and humans. For example, after use, disposable bags are stored and then incinerated. However, it is easy to imagine that bodily secretions, including bacteria and viruses, could leak out of the bag during storage due to the bag's waterproofing defects. As mentioned above, CMC-PE sintered filters only provide instantaneous waterproofing, but they lack long-term waterproofing. In contrast, if PAS powder or a CMC / PAS mixed powder is used instead of CMC powder, the instantaneous waterproofing is inferior to that of CMC powder, but the water retention is superior, thereby solving the long-term waterproofing problem.

[0021] As new technologies for improving the three performance characteristics of breathability, waterproofness, and pathogen barrier properties that must be simultaneously satisfied by the above-mentioned CMC / PE sintered body filters and the like, filter technology has been developed in recent years that combines breathability, instantaneous waterproofness, and long-term waterproofness, while also satisfying the function of pathogen barrier properties, by using a porous polytetrafluoroethylene (PTFE) film in combination with an electrically charged nonwoven fabric (Patent Document 3), or filter technology that is composed of two types of materials, solid (powder) CMC and an electrically charged nonwoven fabric, with the electrically charged nonwoven fabric being placed downstream of the CMC in the direction of the flow of exhaled air within the body (Patent Document 4).

[0022] The combined technology of a mechanical mechanism dependent on pore size and electrostatic capture has been put to practical use in air purifiers incorporating charged nonwoven fabrics (Patent Documents 5 to 7). However, charged nonwoven fabrics (Non-Patent Document 1), which are known to have their charge significantly reduced by droplets containing water, especially organic matter, are not suitable for use in filters for disposable medical bags that handle fluids containing a mixture of gas and bodily secretions, saline, and waste liquids such as blood. This is because, due to unexpected use or an accidental accident, moisture inside the disposable bag could reach the charged nonwoven fabric, causing it to lose its charge, reducing its pathogen barrier properties and allowing pathogens to be released to the outside. Therefore, to solve this problem and achieve a higher level of safety than ever before, it is necessary to use a filter layer other than the charged nonwoven fabric that can remove pathogens.

[0023] In Patent Document 4, the inventors of the present application revealed that by placing an electrically charged nonwoven fabric downstream of a layer structure (hydrophobic water-swelling filter) in which a hydrophilic swelling material powder such as CMC is sandwiched between two sheets of hydrophobic porous film such as flat nonwoven fabric, a filter can be constructed that simultaneously satisfies three performance requirements: breathability, instantaneous and long-term waterproofness, and pathogen barrier properties. However, the structure of the above invention does not have the function of inactivating bacteria and viruses. Furthermore, this structure is based on the use of a flat filter, and therefore has problems in terms of space saving, minimizing parts that are at risk of getting wet, and easy installation.

[0024] US Patent Application Publication No. 2014 / 0296805 Specification Utility Model Registration No. 3203434 Specification Japanese Patent No. 7055379 Publication Japanese Patent No. 6964361 Publication Japanese Patent Application Laid-Open No. 2008-132405 Publication Japanese Patent No. 5293327 Publication Japanese Patent Application Laid-Open No. 2014-042538

[0025] Chemical Engineering Journal, Vol. 18, No. 2, p. 240 (1992) Akito Kiba, Journal of the Society of Fiber Science and Technology (Fibers and Industry), Vol. 51, No. 5, pp. 206-210 (1995) Takeshi Konishi, Journal of the Society of Fiber Science and Technology (Fibers and Industry), Vol. 49, No. 2, pp. 56-60 (1993) News Release, September 3, 2021, Osaka Medical and Pharmaceutical University / Sakai Chemical Industry Co., Ltd. https: / / www.ompu.ac.jp / news / of2vmg000000f0x1.html

[0026] An object of the present invention is to provide a molded filter in a final shape that can inactivate pathogens themselves by using a laminated composite filter that combines a sintered polyethylene (PE) body carrying sodium carboxymethylcellulose (CMC) with a nano-zinc oxide kneaded nonwoven fabric, so as to ensure safety even when the charge is lost upon reaching the charged nonwoven fabric and the pathogen barrier property is reduced, as described above, and a disposable bag that incorporates this molded filter. Another object of the present invention is to provide a manufacturing method for producing this molded filter into a cylindrical shape with a bottom that is advantageous for incorporation into a disposable bag.

[0027] The molded filter for a medical suction device system according to the present invention is configured as follows: A medical suction device system including a suction port for connecting a suction catheter for introducing exhaled breath and bodily secretions from a patient or user, a rigid container body and its lid, a flexible disposable bag provided in a space formed by the rigid container body and the lid, for storing only the bodily secretions of the exhaled breath and bodily secretions and configured to be detached from the rigid container and discarded when the bodily secretions reach a predetermined amount, and an outlet provided in the rigid container body for discharging the exhaled breath other than the stored bodily secretions by an aspirator body outside the rigid container, wherein the disposable bag has at least the suction port and an exhaust outlet communicating with the outlet, and a ventilation part airtightly attached to the disposable bag, a molded filter that is built into the ventilation part, is installed downstream of the disposable bag in order to prevent the passage of bacteria and viruses that may be contained in the exhaled air and the bodily secretions, and is configured so that the exhaled air other than the bodily secretions always passes through before being sucked into the inhaler main body, the molded filter having a cylindrical shape with a bottom, and is composed of an outer layer that forms the outer part of the bottomed cylinder and an inner layer that forms the inner part, and the exhaled air is configured to pass through the outer layer and then the inner layer, The outer layer comprises at least two layers of laminated nonwoven fabric including a nonwoven fabric and an electrically charged nonwoven fabric, or at least three layers of laminated nonwoven fabric including a nonwoven fabric, porous PTFE, and an electrically charged nonwoven fabric, the electrically charged nonwoven fabric being positioned downstream of the nonwoven fabric and the porous PTFE in terms of the internal exhaled air, and the inner layer comprises a sintered body of polyethylene (PE) or polypropylene (PP) carrying sodium carboxymethyl cellulose (CMC) powder or sodium polyacrylate (PAS) powder, or a powder mixture of both, and the outer layer is integrated with the inner layer.

[0028] The outer layer may be formed, along the direction of the flow of internal exhaled air, as two layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric, or three layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric, or three layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric.

[0029] Alternatively, the outer layer may be formed, along the direction of the flow of internal exhaled air, as two layers of nonwoven fabric / charged nonwoven fabric, or three layers of nonwoven fabric / charged nonwoven fabric / nonwoven fabric, or three layers of nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nonwoven fabric / porous PTFE / charged nonwoven fabric / nonwoven fabric.

[0030] The nano-zinc oxide mixed nonwoven fabric is preferably produced by a spunbond method using polypropylene or nylon 66 resin as a raw material.

[0031] The nonwoven fabric is preferably a single-layer spunbond nonwoven fabric produced by the spunbond method, or a spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminated with a meltblown nonwoven fabric produced by the meltblown method.

[0032] The electrically charged nonwoven fabric is preferably produced by a melt-blown method using polypropylene as a raw material.

[0033] The present invention also provides a method for producing the molded filter. The molded filter has a cylindrical shape with a bottom and is composed of an outer layer that forms the outside of the bottomed cylinder and an inner layer that forms the inside, the exhaled air is configured to pass through the outer layer and then the inner layer, the outer layer is composed of a two- to four-layer laminated nonwoven fabric, with a nonwoven fabric and an electrically charged nonwoven fabric arranged downstream of the exhaled air, and the inner layer is an integrated structure composed of a sintered body of polyethylene (PE) or polypropylene (PP) that carries sodium carboxymethylcellulose (CMC) powder, sodium polyacrylate (PAS) powder, or a mixed powder of the two, wherein an outer layer side surface is produced by cutting the laminated nonwoven fabric into at least one curved shape that is capable of covering the entire outer side surface of the inner layer, and the laminated nonwoven fabric is cut so as to completely cover the outside of the bottom surface of the inner layer to produce an outer layer top surface, the outer layer side surface covers the entire side surface of the inner layer, and the outer layer top surface completely covers the outside of the bottom surface of the inner layer.

[0034] It is preferable to use a crimp seal at at least one of the following locations: the joining of the ends of the outer layer and the inner layer on the open side of the bottomed cylinder, the joining of the outer layer side surfaces when the outer layer side surfaces consist of two or more, and the joining of the end on the bottom side of the outer layer side surface and the peripheral end of the outer layer top surface.

[0035] The outer layer side surface may be composed of two or more curved portions, and opposing ends of each of the outer layer side surfaces may be provided with outwardly folded portions for joining.

[0036] Furthermore, the folded portions of the outer layer side surfaces may be joined together by crimp sealing.

[0037] The outer layer and the inner layer may be integrated by holding the top surface and the side surfaces of the outer layer in close contact with the inner layer using a molded outer frame, and the molded outer frame may further include a breathable bottom support frame that holds the bottom portion of the inner layer covered by the side surfaces of the outer layer in close contact, and may further include a side support frame extending from the bottom support frame toward the open side of the inner layer.

[0038] The side support frame may have a protrusion extending from one end to the other end in the direction of the central axis of the inner layer, and when the inner layer covered with the outer layer side surface is attached to the molding outer frame, the opposing ends of the outer layer side surface may be abutted against the protrusion.

[0039] In addition, instead of integrating the molded filter using the molded outer frame, the molded filter may be formed by welding and fixing at least the outer periphery of the top surface of the outer layer and the outer periphery of the bottom surface of the inner layer, one end of the outer layer side surface parallel to the longitudinal direction of the inner layer and the side surface of the inner layer, and the overlapping portion of the other end of the outer layer side surface going around the periphery of the side surface of the inner layer and the one end using an ultrasonic welding machine to integrate the outer layer and the inner layer.

[0040] The present invention also provides a disposable bag for a medical suction system using the molded filter. The disposable bag for a medical suction system according to the present invention is configured as follows: In a medical suction system including a suction port for connecting a suction catheter for introducing exhaled breath and bodily secretions from a patient or user, a rigid container body and its lid, a flexible disposable bag provided in a space formed by the rigid container body and the lid, for storing only the bodily secretions of the exhaled breath and bodily secretions and for detaching from the rigid container and discarding when a predetermined amount of the bodily secretions has been stored, and an outlet provided in the rigid container body for discharging the stored exhaled breath other than the bodily secretions by an aspirator body outside the rigid container, the disposable bag has at least the suction port and an exhaust outlet communicating with the outlet, and is equipped with a ventilation part airtightly attached to the disposable bag, a molded filter that is built into the ventilation part and is placed downstream of the disposable bag in order to prevent the passage of bacteria and viruses that may be contained in the bodily exhaled air and the bodily secretions, and is configured so that the bodily exhaled air other than the bodily secretions always passes through before being sucked into the inhaler main body, the molded filter having a cylindrical shape with a bottom, and comprising an outer layer that forms the outer part of the bottomed cylinder and an inner layer that forms the inner part, the air and the bodily exhaled air pass through the inner layer after passing through the outer layer, and is made of a laminated nonwoven fabric of at least two layers including a nonwoven fabric and an electrically charged nonwoven fabric, or at least three layers including a nonwoven fabric, porous PTFE, and an electrically charged nonwoven fabric, the electrically charged nonwoven fabric being located downstream of the nonwoven fabric and the porous PTFE in terms of the bodily exhaled air, and the inner layer has an integrated structure made of a sintered body of PE or PP that carries CMC powder or PAS powder, or a mixed powder of both.

[0041] The outer layer may be composed, along the direction of flow of the air and the internal exhaled breath, of two layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric, or three layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric, or three layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric.

[0042] Alternatively, the outer layer may be composed, along the direction of the flow of internal exhaled air, of two layers of nonwoven fabric / charged nonwoven fabric, or three layers of nonwoven fabric / charged nonwoven fabric / nonwoven fabric, or three layers of nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nonwoven fabric / porous PTFE / charged nonwoven fabric / nonwoven fabric.

[0043] The nano-zinc oxide mixed nonwoven fabric is preferably produced by a spunbond method using polypropylene or nylon 66 resin as a raw material.

[0044] The nonwoven fabric is preferably a single-layer spunbond nonwoven fabric produced by the spunbond method, or a spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminated with a meltblown nonwoven fabric produced by the meltblown method.

[0045] The electrically charged nonwoven fabric is preferably produced by a melt-blown method using polypropylene as a raw material.

[0046] If the laminated molded filter according to the present invention is applied to a medical suction device system, it will be possible to inactivate pathogens themselves, as described above, and therefore even if moisture reaches the charged nonwoven fabric, causing it to lose its charge and reducing its pathogen barrier properties, a higher level of safety can be ensured than before.

[0047] FIG. 1 is a schematic diagram of the basic system of a current medical suction device. FIG. 2 is a schematic cross-sectional view of a bottomed cylindrical composite filter consisting of an outer layer and an inner layer, used in a disposable bag according to the present invention. FIG. 3 shows schematic cross-sectional views of layer structures such as a laminated nonwoven fabric constituting the outer layer of a composite filter used in a disposable bag according to the present invention, where (A) shows an example of a two-layer structure of nonwoven fabric / charged nonwoven fabric, (B) shows an example of a three-layer structure of nonwoven fabric / charged nonwoven fabric / nonwoven fabric, and (C) shows an example of a four-layer structure of nonwoven fabric / porous PTFE / charged nonwoven fabric / nonwoven fabric. FIG. 4 is a perspective view showing an outline of one example of a process for producing a molded filter used in a disposable bag according to the present invention. FIG. 5 is a perspective view showing an outline of another example of a process for producing a molded filter used in a disposable bag according to the present invention. FIG. 6 is a perspective view showing an outline of yet another example of a process for producing a molded filter used in a disposable bag according to the present invention. Fig. 7 is a perspective view of a ventilation component to be attached to a disposable bag according to the present invention. Fig. 8(A) is a perspective view of a ventilation component to be attached to a disposable bag according to the present invention and a molded filter before being set therein, and Fig. 8(B) is a perspective view of the molded filter set therein. Fig. 9 is a cross-sectional view of a ventilation component to be attached to a disposable bag according to the present invention and a molded filter set therein. Fig. 10(A) and (B) are perspective views of a ventilation component to be attached to a disposable bag according to the present invention and a molded filter according to another embodiment set therein, seen from different angles. Fig. 11 is a perspective view showing the molded filter according to the present invention attached to a disposable bag.

[0048] Considering the issue of pore size, which has a significant impact on filter performance, and pathogen barrier properties, filter capture mechanisms include the following mechanical mechanisms: (a) sieving, (b) inertial impaction, (c) interception, and (d) diffusion. Table 2 lists the sieve diameters of nonwoven fabrics (meltblown sieves / spunbond sieves) and the target particle sizes for each capture mechanism. Spunbond sieves can capture bacteria (sizes up to 1 μm) but allow coronaviruses (sizes up to 0.1 μm) to pass through. In contrast, meltblown sieves without electrostatic charging can cause coronaviruses to collide with the comb, but they are released again and are not captured.

[0049] (Table 2) List of filter mechanism indicators (coronavirus diameter: up to 0.1 μm)

[0050]

[0051] Generally, the smaller the pore size, the higher the pathogen barrier property due to a mechanical mechanism, but the disadvantage of higher pressure loss occurs. To avoid this, by incorporating a mechanism different from the mechanical mechanism, "pathogen capture by electrostatic charge," it is possible to ensure both airflow and improved pathogen barrier property (Non-Patent Document 2).

[0052] Therefore, by using a CMC / PE sintered filter or the like to function as a sieve and utilizing the Coulomb force of the charged nonwoven fabric, a collection mechanism can be constructed that combines the mechanical mechanisms of the filter (a-d) and the electrostatic adsorption mechanism (e). The electrostatic Coulomb force alone is capable of adsorbing a significant portion of virus-sized particles, 0.05 to 1.0 μm, and this can be expected to provide an effective barrier against pathogens in the virus size range of 1 μm or less at the exhaust port of the disposal bag. As described in Patent Document 7, charged nonwoven fabrics can use static electricity to capture fine dust particles of submicron and nano sizes that are normally difficult to remove.

[0053] A typical method for producing a charged nonwoven fabric is to manufacture the fabric using engineering plastics such as PP resin or nylon 66 resin as raw material, and then charge the fabric by corona discharge or hydrocharging. The amount of charge is 2.0 x 10 in terms of surface charge density.－１０ Coulomb / cm ２ The above is desirable. 　 The meltblown method is the preferred manufacturing method because it allows for the production of extremely fine fibers and thin fabrics, but the spunbond method is also possible. PP meltblown electrostatically charged nonwoven fabrics have a thickness of 0.12 to 0.40 mm and a basis weight (mass of fabric per unit area) of 10 to 40 g / g m. ２ , and the air permeability is 40cc / cm at 20g ２ / s, 20cc / cm at 40g ２ Types such as / s are produced.

[0054] Table 3 summarizes the particle sizes of bacteria, viruses, pores in charged nonwoven fabrics (meltblown / spunbond), and nano-zinc oxide.

[0055] (Based on Non-Patent Documents 2 and 3)

[0056] As shown in Tables 2 and 3, the maximum pore size of the meltblown nonwoven fabric is approximately 29 nm, which is one-third the size of the coronavirus, which is approximately 100 nm, and due to the adsorption effect caused by electrostatic charges, it is thought to be almost impossible for the coronavirus to pass through the pores that form the comb patterns of the meltblown nonwoven fabric under the pressure of an air flow rate of 28.3 L / min (flow velocity 27 m / s), which is the specified condition for the test (based on ASTM F2101).

[0057] The composite filter of the present invention has an inner layer made of a CMC-PE sintered compact or the like, and an outer layer consisting of three layers of nano-zinc oxide kneaded nonwoven fabric / charged nonwoven fabric / nano-zinc oxide kneaded nonwoven fabric, or two layers of nano-zinc oxide kneaded nonwoven fabric / charged nonwoven fabric, covering the entire upstream side of the inner layer. As a basic test of the pathogen barrier properties of this composite filter, the bacterial capture efficiency (BFE) and virus capture efficiency (VFE) were measured for the CMC-PE sintered compact alone, the spunbond (SB) nonwoven fabric alone, the meltblown charged nonwoven fabric alone, and a laminate with the CMC-PE sintered compact, and the pathogen adsorption performance of the charged nonwoven fabric in particular were evaluated (November 2018 / Kaken Test Center). The results are shown in Table 4.

[0058] (Table 4) Bacteria and virus adsorption of each filter layer

[0059] *The charged nonwoven fabric is placed downstream of the airflow. **Nonwoven fabric / CMC / nonwoven fabric (Patent Document 4)

[0060] In the cases of CMC-PE sintered compact / charged nonwoven fabric and SB nonwoven fabric / CMC-PE sintered compact / SB nonwoven fabric / charged nonwoven fabric, both showed a BFE of 99.9% or higher. When used as a filter for internal exhaled air aspirated and exhausted by a medical suction device, it was confirmed that 99.9% or higher of viruses and bacteria in the exhaled air were adsorbed. In BFE and VFE tests conducted at the Kaken Test Center on six samples in which charged nonwoven fabric was placed downstream of the airflow, the collection efficiency of all samples was 99.9% or higher. This demonstrates that the results are reliable.

[0061] What is important here is that, for example, when a coronavirus (as well as an influenza virus) that has passed through the SB nonwoven fabric layer collides with the electrically charged nonwoven fabric layer, it cannot pass through the electrically charged nonwoven fabric, which has pores that are about one-third the size of the virus itself, and therefore when it is attracted by the electrical attraction of the electrically charged nonwoven fabric, it is captured in its entirety on the surface of the electrically charged nonwoven fabric layer. This means that the captured viruses are positioned in a state where they can come into close proximity to and into contact with the surface of the SB nonwoven fabric layer into which nano zinc oxide (nZnO), described below, has been kneaded.

[0062] (Antiviral Effect of Nonwoven Fabrics Containing Nano-Zinc Oxide) Nano-zinc oxide exhibits photocatalytic properties, and it is known that its reaction with light results in an antiviral effect (Non-Patent Document 4: News Release, September 3, 2021, Osaka Medical and Pharmaceutical University / Sakai Chemical Industry Co., Ltd.). Furthermore, experiments conducted by nano-zinc oxide manufacturers have confirmed that coronaviruses are almost completely inactivated by the photocatalytic effect when exposed to nano-zinc oxide, a photocatalyst, for four hours or more. Furthermore, this effect is also observed in the dark. Furthermore, tests conducted by the inventors at a Chinese analytical institute have confirmed that coronaviruses are also inactivated when exposed to SB nonwoven fabrics made from PP containing nano-zinc oxide for four hours or more.

[0063] In the case of disposable bags attached to medical suction machines, which is the most common method of using filters, the average time a disposable bag is used by one user is about one day, so most coronaviruses are inactivated by the filter mixed with nano zinc oxide during use, and it is thought that most coronaviruses will be inactivated if at least four hours or more elapses are allowed between the time the disposable bag is removed from the suction machine system and the time it is discarded.

[0064] (Contact with Nano-Zinc Oxide Nonwoven Fabric and Inactivation of Viruses Adsorbed to Charged Nonwoven Fabric) Next, we consider the effect of the photocatalyst on coronaviruses in the three-layer or two-layer laminated nonwoven fabric made of nano-zinc oxide-mixed SB nonwoven fabric (hereinafter referred to as nZnO-SB nonwoven fabric). At the contact interface between the nZnO-SB nonwoven fabric and the charged nonwoven fabric arranged downstream of it, coronaviruses adsorbed near the surface of the charged nonwoven fabric due to the electrical attraction of the charged nonwoven fabric are thought to be in contact with the surface of the nZnO-SB nonwoven fabric, which is simultaneously exhibiting a photocatalytic effect, or to be located within the area where the photocatalytic effect is exhibited. Furthermore, as described above, this contact typically lasts for four hours or more. As a result, coronaviruses adsorbed to the surface of the charged nonwoven fabric are thought to be inactivated by the effect of the nZnO-SB nonwoven fabric at the contact interface between these two types of nonwoven fabric.

[0065] (Possibility of virus inactivation due to loss of charge in electrically charged nonwoven fabric) If an electrically charged nonwoven fabric loses its charge due to water leakage, there is a risk of inactivation, in which its function to inactivate coronaviruses and the like will no longer work, as described above, but in reality this is a problem that can be ignored, as explained below. If viruses are released from a meltblown electrically charged nonwoven fabric due to wetting with water, one of two things can happen: (1) the water will reach the layer of CMC / PE sintered compact, etc., and the CMC, etc. will dissolve, causing ventilation itself to stop, or (2) the virus will be captured by or pass through the subsequent layer of CMC / PE sintered compact, etc.

[0066] Therefore, the risk of deactivation occurs when the electrostatic charge of the meltblown electrostatic nonwoven fabric disappears due to slight water exposure, and the airflow through the CMC-PE sintered compact or other filter does not stop, allowing viruses such as coronavirus to leak through the filter. In this case, the virus capture efficiency of the CMC-PE sintered compact is 92.4%, leaving the possibility of the remaining 7.6% leaking. Research on this issue and quantitative experimental data have not yet been obtained. The currently most reliable method for completely removing this worst-case remaining 7.6% is to place an nZnO-SB nonwoven fabric and / or an electrostatic nonwoven fabric as a secondary filter downstream of the CMC-PE sintered compact or other filter.

[0067] (Composite Integrated Structure of Laminated Nonwoven Fabric and CMC / PE Sintered Compacts, etc.) The cylindrical shape with a bottom, devised to meet functional requirements such as space saving and minimizing areas at risk of water exposure, is currently widely used for CMC / PE sintered compacts, etc. Two possible configurations for a composite integrated structure of a laminated nonwoven fabric and a CMC / PE sintered compact, etc., are: either the laminated nonwoven fabric is placed as an outer layer on the outside of the cylindrical CMC / PE sintered compact, etc. with a bottom, or as an inner layer on the inside of the CMC / PE sintered compact, etc. However, placing the laminated nonwoven fabric on the inside of the cylindrical CMC / PE sintered compact makes it extremely difficult to cover the inside of the cylindrical CMC / PE sintered compact, and furthermore, it makes it nearly impossible to fit the composite filter into a disposable bag. Therefore, covering the CMC / PE sintered compact, etc. with the laminated nonwoven fabric as an outer layer is essentially the only possible integrated structure configuration. A cross-sectional view of this composite filter is shown in Figure 2.

[0068] For current medical suction devices, the ventilation performance required for disposable bags is that the ventilation filter inside the disposable bag must have an airflow rate of 20 L / min or more at a suction force (under differential pressure) of 60 kPa or more for high suction pressure / high flow rate types (JIS T7208-1:2012 Electric suction devices - Safety requirements, Article 59, Paragraph 5), and that the low suction pressure / low flow rate type must have an airflow rate of 0.5 to 10 L / min at a suction pressure of 20 kPa or less (Article 59, Paragraph 7).

[0069] The outer dimensions and outer surface area of ​​the CMC / PE sintered body are determined based on the above criteria so as to ensure typical values ​​of the air flow rate in a given time, for example, a suction flow rate at low pressure: 14.2 L / -27 kpa, and a suction flow rate at high pressure: 37.0 L / -80 kpa. In this case, the surface area of ​​the CMC / PE sintered body is: total surface area: 1,801 mm ２ , Top surface area: 270 mm ２ , top surface / total surface area: 16.0%. Therefore, when integrating with a laminated nonwoven fabric, it is necessary to ensure the outer surface area of ​​this PE sintered body and to tightly cover the entire outer surface.

[0070] Figure 3 is a schematic diagram showing the layer configuration of a laminated nonwoven fabric used as the outer layer 20 of the composite filter of the present invention. (A) shows a two-layer configuration of SB nonwoven fabric 26 / MB-charged nonwoven fabric 27, and (B) shows a three-layer configuration of SB nonwoven fabric 26 / MB-charged nonwoven fabric 27 / SB nonwoven fabric 26, and as described above, the charged nonwoven fabric 27 needs to be positioned downstream of the nonwoven fabric 26 in terms of exhaled air. (C) shows an example in which porous PTFE 28 is further laminated to further enhance water resistance, resulting in a four-layer configuration of SB nonwoven fabric 26 / porous PTFE 28 / MB-charged nonwoven fabric 27 / SB nonwoven fabric 26. In this case, the order of adjacent SB nonwoven fabrics 26 and porous PTFE 28 may be reversed. The SB nonwoven fabric 26 may be a single layer of SB nonwoven fabric, or a laminated nonwoven fabric with an MB nonwoven fabric sandwiched in between, such as SB nonwoven fabric / MB nonwoven fabric / SB nonwoven fabric (SMS) nonwoven fabric. Furthermore, the SB nonwoven fabrics (A) to (C) may be replaced with nZnO-SB nonwoven fabric to further enhance resistance to viruses as described above.

[0071] It is basically difficult to process unevenness into a single-layer flat nonwoven fabric or a laminated nonwoven fabric with a sandwich structure of two or three layers. Therefore, in order to completely cover the outside of the inner layer 30 of a cylindrical CMC-PE sintered body with a bottom, into which the inhaled / exhaled air flows, it is necessary to form an outer layer side surface 22 that covers the entire side surface of the inner layer 30 by joining a flat surface (outer layer top surface) 24 that covers the bottom surface and one or more curved side surfaces.

[0072] Furthermore, in order for the coating of the outer layer 20 of the laminated nonwoven fabric to achieve the function of capturing and inactivating bacteria and viruses in exhaled air, it is necessary to completely eliminate the possibility of inhaled and exhaled air passing only through the inner layer 30 without passing through the outer layer 20. To prevent this exhalation from passing directly through the inner layer 30 without passing through the outer layer 20, it is necessary to completely seal the ends of the contact surface between the outer layer 20 and the inner layer 30 so that the inhaled and exhaled air passing through the outer layer 20 does not leak from the ends. In other words, sealing the ends of the contact surface between the outer layer 20 and the inner layer 30 is an essential condition for preventing leakage of inhaled and exhaled air.

[0073] At the open end of a bottomed cylindrical container, it is difficult to perform conventional heat fusion between a PP-based laminated nonwoven fabric and a CMC / PE sintered body, etc., due to the dissimilar materials. Furthermore, as described in detail below, heat fusion between the laminated nonwoven fabrics on the outer layer side surface 22, and heat fusion between the bottom edge of the outer layer side surface 22 of the laminated nonwoven fabric and the peripheral edge of the outer layer top surface 24 of the laminated nonwoven fabric (jointed portion 25 in Figure 2 ) leaves uncertainty about the sealability of the fused surfaces. Therefore, pressure sealing using the outer frame of the molded product is preferred for sealing the contact end surfaces to prevent leakage.

[0074] Figure 4 shows an overview of the manufacturing process for a laminated nonwoven fabric / molded filter, such as a CMC-PE sintered compact, according to a first embodiment of the present invention. First, all sides of the inner layer 30, such as a CMC-PE sintered compact, are surrounded by the outer layer side surface 22 of a rectangular laminated nonwoven fabric cut to completely cover it (1-1). Next, the outer layer top surface 24 of the laminated nonwoven fabric, cut into a circle to cover the bottom surface of the inner layer 30, is placed at the bottom of a molding support frame 32, and the inner layer 30, now covered by the outer layer side surface 22, is inserted by pressing it against the outer layer top surface 24 (1-2). In this way, a molded filter 300 integrated with the molding support frame 32 is completed (1-3). Note that (1-4) is a view of the completed molded filter 300 from below.

[0075] FIG. 5 is a diagram illustrating an outline of the manufacturing process for a laminated nonwoven fabric / molded filter, such as a CMC-PE sintered compact, according to a second embodiment of the present invention. First, a laminated nonwoven fabric sheet 21 is prepared by compression, with multiple parallel concave curved surfaces that fit half of the cylindrical outer surface of the inner layer 30, such as a CMC-PE sintered compact (2-1). Between the concave curved surfaces of the sheet 21, folds 23 are provided for later joining the half curved surfaces. Next, multiple inner layers 30 are arranged on top of the sheet 21, and another sheet 21 is placed on top of that from above the array of inner layers 30, after which the sheet is cut to separate the outer layer 20 / inner layer 30. Alternatively, the laminated nonwoven fabric sheet 21 may be pre-cut to the height of the inner layer 30 to prepare the outer layer side surface 22, which is then sandwiched from both sides (2-2). The folded portions 23 at both ends of the two outer layer side surfaces 22 are then bonded together by adhesive or heat fusion (2-3).

[0076] Separately, the outer layer top surface 24 of the laminated nonwoven fabric is prepared by cutting it into a circle to fit the bottom surface of the inner layer 30, and inserted into a disk-shaped bottom support frame 34 (2-4). The bottom support frame 34 has fixing grooves 35 in two locations into which the folded portions 23 are inserted and fixed. Finally, the bottom support frame 34 is attached by being in close contact with the inner layer 30 to which the outer layer side surface 22 is fixed, thereby completing the integrated molded filter 300 (2-5). (2-6) is a view of the completed molded filter 300 from above.

[0077] Figure 6 shows an outline of the manufacturing process for a molded filter, such as a laminated nonwoven fabric / CMC-PE sintered compact, according to a third embodiment of the present invention. First, a rectangular outer layer side surface 22 is cut to cover the entire outer surface of the inner layer 30 (3-1), and an intermediate member is then wrapped around the entire side surface of the inner layer 30 (3-2). Next, a circular outer layer top surface 24 that covers the bottom surface of the inner layer 30 is placed inside a molding support frame 32 (3-3). This molding support frame 32 is composed of a ring-shaped bottom support frame 34 that covers the bottom surface of the inner layer 30, sandwiching the outer layer top surface 24 as in the previous embodiment, and a side support frame 36 that extends upward from one point around the bottom support frame 34.

[0078] This side support frame 36 extends from end to end along the central axis of the inner layer 30, and is provided with V-shaped cross-section side support frame protrusions 37 with their tips facing the central axis. The intermediate member is then set and crimped so that the V-shaped tips of the side support frame protrusions 37 are positioned on the linear portion where the rectangular outer layer side surface 22 wrapped around the outside of the inner layer 30 faces (3-3). This structure improves airtightness when the molded filter is set in a disposal bag holder (described below). (3-4) is a view of the completed molded filter 300 from the direction of the side support frame 36, and (3-5) is a view from the side.

[0079] FIG. 7 is a perspective view showing the appearance of a ventilation component 400 to which a molded filter 300, which is formed by integrating the composite filter 200 produced in the above-described process with a molded support frame 32, is attached. The ventilation part 400 is made by integral molding using a material such as PP, and is composed of a suction port 41 for connecting the suction catheter 18 for introducing exhaled air from inside the patient's body, a cap 42 for closing the suction port 41 after suction is completed, a rigid container mounting structure 43 for fitting and fixing the disposable bag to the rigid container body 120, an exhaust port 44 for allowing the exhaled air that has passed through the molded filter 300 to flow into the rigid container body 120 which is made negative pressure by the suction device body 130, a disposal bag joint 45, a suction port outlet 46 which is an outlet for the exhaled air into the disposal bag, and a check valve 47 which prevents the exhaled air and the like from inside the disposal bag from flowing back when suction is stopped, and a molded filter holder 48 which stores the molded filter 300 and has an opening 49 for inhalation.

[0080] Figure 8 shows how to attach the molded filter 300 to the molded filter holder 48 of the ventilation component 400. With the top of the molded filter 300 facing downwards, it is inserted from the bottom of the molded filter holder 48 (A) until it reaches the back (B). As shown in the cross-sectional view of the ventilation component 400 in Figure 9, the inner diameter of the molded filter holder 48 is designed to fit exactly with the outer diameter of the molded filter 300, preventing it from falling off even without being secured from below. Alternatively, the outer diameter of the disposal bag side of the exhaust port 44 is designed to fit the inner diameter of the inner layer 30 of the molded filter 300. Furthermore, during inhalation, the air pressure inside the disposal bag is higher than the air pressure at the exhaust port 44, which presses the molded filter 300 against the upper side of the molded filter holder 48, creating a tighter seal between the two and ensuring that exhaled air always passes through the molded filter 300.

[0081] In the first to third embodiments, the structure and manufacturing method of molded filter 300, which is integrated by a molded outer frame consisting of support frames 32, 34, and 36, are described, but the following describes a manufacturing method of molded filter 300 that does not use a molded outer frame. The nonwoven fabric can be welded using an ultrasonic welding machine, and the steps for manufacturing molded filter 300 using this method are shown below.

[0082] (1) First, a sheet of laminated nonwoven fabric (the nonwoven fabric is either SB MB or SMS) having, for example, a nonwoven fabric / charged nonwoven fabric / nonwoven fabric structure is prepared and punched out into a circle to create outer layer top surface 24. At this time, one or more protrusions extending outward are provided around the periphery of the circle, and it is folded in the direction of the side of inner layer 30. (2) The outer periphery of outer layer top surface 24 is welded to the outer periphery of the bottom surface of inner layer 30 using an ultrasonic welder, so as to cover and fix it to the bottom surface of inner layer 30. (3) Meanwhile, a sheet of the same laminated nonwoven fabric is cut into a tape shape with a width equal to the longitudinal length of the inner layer.

[0083] (4) One end of the tape-like laminated nonwoven fabric is sandwiched inside the folded portion of the outer layer top surface 24 prepared in (1) to serve as the starting point for wrapping around the side surface of the inner layer 30. Then, approximately 5 to 7 mm inside this end is linearly welded along the longitudinal direction of the side surface of the inner layer 30 using an ultrasonic welder. (5) Starting from this initial weld line, the tape-like laminated nonwoven fabric is wrapped around the inner layer while being sealed and pressed, making one full turn, and then overlapping the initial weld line. This overlapping portion is then re-welded from above along the initial weld line using an ultrasonic welder. The excess tape-like laminated nonwoven fabric is then welded using the ultrasonic welder. In this way, the outer layer side surface 22 is covered and fixed to the inner layer side surface. (6) The boundary 25 (see FIG. 2) between the outer periphery of the outer layer top surface 24 and the outer layer side surface 22 is pressed by the suction pressure of the aspirator body 130, so there is no problem with airtightness in this state. However, if the outer periphery of the boundary 25 is welded with an ultrasonic welding machine, the reliability of airtightness can be further improved.

[0084] The composite filter 200 produced by this manufacturing method can be used as an integrated filter 300 as is, since the inner and outer layers are firmly fixed by welding. This eliminates the need to separately fabricate a molded outer frame, significantly reducing the manufacturing cost of the integrated filter 300. Figures 10A and 10B are perspective views of the molded filter 300 of this embodiment, viewed from different directions, before it is attached to the ventilation component 400. As with the molded filters 300 of Examples 1 to 3, the molded filter 300 can be easily attached by inserting it into the molded filter holder 48 from below. During suction, the molded filter 300 is pressed against the inner portion of the molded filter holder 48 by the suction pressure, ensuring stable attachment.

[0085] FIG. 11 shows the final appearance of a disposable bag 500 for a medical suction system after the ventilation component 400 with the molded filter 300 attached thereto is attached by heat sealing or the like to a film bag 50 for storing bodily secretions and the like. The film bag 50 can have a variety of shapes, but is designed to be efficiently stored within the rigid container shown in FIG. 1. The film bag 50 is typically formed by multi-layer inflation molding using linear polyethylene (LLDPE), polyethylene terephthalate (PET) resin, and / or nylon resin (NY), and an adhesive resin. In this embodiment, the film bag 50 has three layers: an outer layer (PET) of 30 μm thick, an adhesive resin layer of 7 μm thick, and an inner layer (LLDPE) of 120 μm thick. The internal volume of this embodiment is 1300 cc.

[0086] Although the above description has been given with reference to the examples, the present invention is not limited thereto, and it will be apparent to those skilled in the art that various changes and modifications can be made within the spirit of the present invention and the scope of the appended claims. For example, although the molded filter has been described as having a cylindrical shape with a bottom in the examples, its cross section may have other similar shapes other than a perfect circle.

[0087] 100 Basic system of medical suction device 11 Intake port 12 Filter 13 Exhaust port 15 Discharge port 16 Suction port 18 Suction catheter 19 Connecting hose 110 Disposable bag 120 Rigid container body 130 Suction device body 200 Composite filter 20 Outer layer 21 Laminated nonwoven fabric sheet 22 Outer layer side surface 23 Folded portion 24 Outer layer top surface 25 Joint portion 26 (Nano zinc oxide) nonwoven fabric 27 Charged nonwoven fabric 28 Porous PTFE 30 Inner layer 300 Molded filter 32 Molded support frame 34 Bottom support frame 35 Fixing groove 36 Side support frame 37 Side support frame protrusion 400 Ventilation part 41 Suction port 42 Cap 43 Rigid container mounting structure 44 Exhaust port 45 Disposal bag joint 46 Suction port outlet 47 Check valve 48 Molded filter holder 49 Opening 50 Film bag 500 Final disposable bag

Claims

1. A medical suction device system comprising: a suction port for connecting a suction catheter for introducing exhaled breath and bodily secretions from a patient or user; a rigid container body and its lid; a flexible disposable bag provided in a space formed by the rigid container body and the lid for storing only the bodily secretions of the exhaled breath and bodily secretions and configured to be removed from the rigid container and discarded when a predetermined amount of the bodily secretions has been stored; and an outlet provided in the rigid container body for discharging the stored exhaled breath other than the bodily secretions by an aspirator body outside the rigid container, wherein the disposable bag has at least the suction port and an exhaust outlet communicating with the outlet, and is equipped with a venting part airtightly attached to the disposable bag; a molded filter that is built into the ventilation part, is installed downstream of the disposable bag in order to prevent the passage of bacteria and viruses that may be contained in the exhaled air and the bodily secretions, and is configured so that the exhaled air other than the bodily secretions always passes through it before being sucked into the inhaler main body, the molded filter having a cylindrical shape with a bottom, and is composed of an outer layer that forms the outer part of the bottomed cylinder and an inner layer that forms the inner part, and the exhaled air is configured to pass through the outer layer and then the inner layer, A molded filter for a medical suction system, wherein the outer layer comprises at least two layers of laminated nonwoven fabric including a nonwoven fabric and an electrically charged nonwoven fabric, or at least three layers of laminated nonwoven fabric including a nonwoven fabric, porous PTFE, and an electrically charged nonwoven fabric, the electrically charged nonwoven fabric being positioned downstream of the nonwoven fabric and the porous PTFE in terms of the internal exhaled air, and the inner layer comprises a sintered body of polyethylene (PE) or polypropylene (PP) carrying sodium carboxymethyl cellulose (CMC) powder or sodium polyacrylate (PAS) powder, or a powder mixture of both, and the outer layer and the inner layer have an integrated structure.

2. The molded filter for a medical suction system according to claim 1, wherein the outer layer is composed of, in the direction of the flow of the internal exhaled air, two layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric, three layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric, three layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric.

3. The molded filter for a medical suction system according to claim 1, wherein the outer layer consists of, in the direction of the flow of internal exhaled air, two layers of nonwoven fabric / charged nonwoven fabric, three layers of nonwoven fabric / charged nonwoven fabric / nonwoven fabric, three layers of nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nonwoven fabric / porous PTFE / charged nonwoven fabric / nonwoven fabric.

4. The molded filter for a medical suction system according to claim 2, wherein the nano-zinc oxide mixed nonwoven fabric is produced by the spunbond method using polypropylene or nylon 66 resin as a raw material.

5. The molded filter for a medical suction system according to claim 3, wherein the nonwoven fabric is a single layer of spunbond nonwoven fabric produced by the spunbond method, or a spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminated with a meltblown nonwoven fabric produced by the meltblown method.

6. The molded filter for a medical suction device system according to claim 2 or 3, wherein the electrically charged nonwoven fabric is produced by the melt-blown method using polypropylene as a raw material.

7. A medical suction device system comprising: a suction port for connecting a suction catheter for introducing exhaled breath and bodily secretions from a patient or user; a rigid container body and its lid; a flexible disposable bag provided in a space formed by the rigid container body and the lid for storing only the bodily secretions of the exhaled breath and bodily secretions and configured to be removed from the rigid container and discarded when a predetermined amount of the bodily secretions has been stored; and an outlet provided in the rigid container body for discharging the stored exhaled breath other than the bodily secretions by an aspirator body outside the rigid container, wherein the disposable bag has at least the suction port and an exhaust outlet communicating with the outlet, and is equipped with a ventilation part airtightly attached to the disposable bag; A molded filter that is built into the ventilation part and is installed downstream of the disposable bag to prevent the passage of bacteria and viruses that may be contained in the exhaled air and the bodily secretions, and is configured so that the exhaled air other than the bodily secretions always passes through before being sucked into the inhaler main body, the molded filter has a cylindrical shape with a bottom and is composed of an outer layer that constitutes the outer part of the bottomed cylinder and an inner layer that constitutes the inner part, the internal exhaled air is configured to pass through the outer layer and then the inner layer, the outer layer is composed of a laminated nonwoven fabric of at least two layers including a nonwoven fabric and an electrically charged nonwoven fabric, or at least three layers including a nonwoven fabric, porous PTFE, and an electrically charged nonwoven fabric, the electrically charged nonwoven fabric is arranged downstream of the nonwoven fabric in terms of the internal exhaled air, and the inner layer is composed of a sintered body of polyethylene (PE) or polypropylene (PP) that carries sodium carboxymethylcellulose (CMC) powder or sodium polyacrylate (PAS) powder, or a mixed powder of both, and the molded filter has a structure in which the outer layer and the inner layer are integrated, the method comprising: cutting the laminated nonwoven fabric into the shape of at least one sheet that can cover the entire outer side surface of the inner layer, to prepare an outer layer side surface, cutting the laminated nonwoven fabric so as to completely cover the outside of the bottom surface of the inner layer, to prepare an outer layer top surface,a step of covering the entire side surface of the inner layer with the side surface of the outer layer, and completely covering the outside of the bottom surface of the inner layer with the top surface of the outer layer.

8. A method for manufacturing a molded filter as described in claim 7, wherein the outer layer and the inner layer are integrated by holding the outer layer top surface and the outer layer side surface in close contact with the inner layer using a molded outer frame.

9. A method for manufacturing a molded filter as described in claim 8, wherein the molded outer frame includes a breathable bottom support frame that tightly holds at least the bottom portion of the inner layer covered by the side surface of the outer layer, and optionally includes a side support frame extending from the bottom support frame toward the open side of the inner layer.

10. A method for manufacturing a molded filter as described in claim 8, wherein pressure sealing is used in at least one of the following: joining the respective ends of the outer layer and the inner layer on the open side of the bottomed cylinder; joining the outer layer side faces when the outer layer side faces consist of two or more; and joining the end on the bottom side of the outer layer side face with the peripheral end of the top surface of the outer layer.

11. A method for manufacturing a molded filter as described in claim 7, wherein the outer layer side surface is composed of two or more curved portions, and each of the opposing ends of the outer layer side surface is provided with an outward bent portion for joining.

12. The method for producing a molded filter according to claim 11, wherein the folded portions of the outer layer side surfaces are joined together by crimp sealing.

13. A method for manufacturing a molded filter as described in claim 9, wherein the side support frame has a protrusion extending from one end to the other end in the direction of the central axis of the inner layer, and when the inner layer covered with the outer layer side surface is attached to the molded outer frame, the opposing ends of the outer layer side surface are abutted against the protrusion.

14. A method for manufacturing a molded filter as described in claim 7, wherein at least the outer periphery of the top surface of the outer layer and the outer periphery of the bottom surface of the inner layer, one end of the outer layer side surface parallel to the longitudinal direction of the inner layer and the side surface of the inner layer, and the overlapping portion of the other end of the outer layer side surface going around the periphery of the side surface of the inner layer and the one end are welded and fixed with an ultrasonic welding machine to integrate the outer layer and the inner layer.

15. A method for producing a molded filter according to claim 7, wherein the outer layer consists of, along the direction of the flow of exhaled air in the body, two layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric, or three layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric, or three layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric.

16. A method for producing a molded filter as described in claim 7, wherein the outer layer consists of, along the direction of the flow of internal exhaled air, two layers of nonwoven fabric / charged nonwoven fabric, or three layers of nonwoven fabric / charged nonwoven fabric / nonwoven fabric, or three layers of nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nonwoven fabric / porous PTFE / charged nonwoven fabric / nonwoven fabric.

17. A medical suction device system comprising: a suction port for connecting a suction catheter for introducing exhaled breath and bodily secretions from a patient or user; a rigid container body and its lid; a flexible disposable bag provided in a space formed by the rigid container body and the lid for storing only the bodily secretions of the exhaled breath and bodily secretions and configured to be removed from the rigid container and discarded when the bodily secretions reach a predetermined amount; and an outlet provided in the rigid container body for discharging the exhaled breath other than the stored bodily secretions by an aspirator body outside the rigid container, wherein the disposable bag has at least the suction port and an exhaust outlet communicating with the outlet, and is equipped with a ventilation part airtightly attached to the disposable bag; a molded filter that is built into the ventilation part and is installed downstream of the disposable bag to prevent the passage of bacteria and viruses that may be contained in the exhaled air and the bodily secretions, and is configured so that the exhaled air other than the bodily secretions must pass through before being sucked into the inhaler body; 1. A disposable bag for a medical suction system, wherein the molded filter has a cylindrical shape with a bottom, and is composed of an outer layer that forms the outside of the bottomed cylinder and an inner layer that forms the inside, wherein air and the internal exhaled gas pass through the outer layer and then the inner layer, wherein the outer layer is composed of a laminated nonwoven fabric of at least two layers including a nonwoven fabric and an electrically charged nonwoven fabric, or at least three layers including a nonwoven fabric, PTFE, and an electrically charged nonwoven fabric, and wherein the electrically charged nonwoven fabric is located downstream of the nonwoven fabric in terms of the internal exhaled gas, and wherein the inner layer is composed of a sintered body of polyethylene (PE) or polypropylene (PP) that carries sodium carboxymethylcellulose (CMC) powder or sodium polyacrylate (PAS) powder, or a powder mixture of both, and wherein the outer layer is integrated with the inner layer.

18. The disposable bag for a medical suction system according to claim 17, wherein the outer layer is composed of, in the direction of flow of the air and the internal exhaled gas, two layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric, three layers of nano-zinc oxide mixed nonwoven fabric / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric, three layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nano-zinc oxide mixed nonwoven fabric / porous PTFE / charged nonwoven fabric / nano-zinc oxide mixed nonwoven fabric.

19. The disposable bag for a medical suction system according to claim 17, wherein the outer layer is composed of, in the direction of the flow of internal exhaled air, two layers of nonwoven fabric / charged nonwoven fabric, three layers of nonwoven fabric / charged nonwoven fabric / nonwoven fabric, three layers of nonwoven fabric / porous PTFE / charged nonwoven fabric, or four layers of nonwoven fabric / porous PTFE / charged nonwoven fabric / nonwoven fabric.

20. A disposable bag for a medical suction system according to claim 18, wherein the nano-zinc oxide mixed nonwoven fabric is made by the spunbond method using polypropylene or nylon 66 resin as a raw material.

21. The disposable bag for a medical suction system according to claim 19, wherein the nonwoven fabric is a single-layer spunbond nonwoven fabric produced by the spunbond method, or a spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminated with a meltblown nonwoven fabric produced by the meltblown method.

22. A disposable bag for a medical suction device system according to claim 18 or 19, wherein the electrically charged nonwoven fabric is made from polypropylene by the melt-blown method.

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