Antiviral toilet

Abstract

The antiviral toilet includes a base structure including a toilet flush bowl having an upper rim, a toilet seat and lid hinge mounted to the base structure, a filter assembly including a high efficiency particulate air (HEPA) filter disposed in a porous metal filter track housing, the filter assembly being mounted to the underside of the toilet lid concentric with the toilet seat and making uniform surface contact at one end with the upper surface of the toilet seat when the toilet seat and lid are closed, electronics for initiating flushing, a power source for powering the electronics, and at least one visual indication for status notification.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application Publication No. 17 / 392,952, filed August 3, 2021, entitled "Antiviral Commode," and U.S. Provisional Patent Application Publication No. 63 / 061,642, filed August 5, 2020, entitled "Anti-Aerosol Toilet Seat," the disclosures of which are incorporated herein by reference, at a minimum.

[0002] FIELD OF THE INVENTION The present invention relates to the field of plumbed waste collection systems, and more particularly to a method and apparatus for removing contaminants from air displaced by a plumbed waste collection system. [Background technology]

[0003] In the art of waste management, numerous facilities and devices exist that are designed or otherwise adapted to safely collect and / or treat and reuse human biological waste, with the hope of desirably eliminating or at least reducing potentially harmful biological airborne contaminants and / or potentially harmful airborne synthetic toxins and / or gases.

[0004] A typical system for recycling biological human waste, such as feces and urine, includes a collection process that uses toilets and urinals to collect the waste. Human waste may be stored in collection tanks known as septic tanks for periodic collection by vehicles. Human waste may be collected and pumped into a sewer system, eventually arriving at one or more treatment facilities where chemicals and specific processes may be applied to the wastewater to disinfect it from biological and synthetic contaminants. The treated water may then be used for other purposes or released into a natural water drainage system.

[0005] It is known in the art, and numerous studies have been conducted, that waste collection facilities, such as flush toilets, can potentially disperse airborne particles, characteristic of, for example, disease-causing spores, viruses, and other airborne contaminants, into the air surrounding the flush toilet. Such contaminants can remain airborne for a period of time before settling on surfaces surrounding the flush toilet, including toilet surfaces, countertops, sinks, shower or bath unit surfaces, etc.

[0006] A study by Wilcox, Sandoe, and Best, referenced herein and titled "Potential for Aerosolization of Clostridium difficile after flushing toilets," found that C. difficile can be recovered from air samples after a toilet flushes. Samples taken 25 centimeters above the toilet seat were positive for C. difficile. Bioaerosols generated by toilet flushing potentially contribute to environmental contamination within hospitals. Preventative measures (toilet covers) should be evaluated as an intervention to prevent toilet-related environmental contamination in clinical settings.

[0007] Other studies have demonstrated the need to keep toilets clean during the novel coronavirus pandemic to prevent the transmission of bacteria and pathogens. The health of toilet users may be affected by pathogens contained in airborne aerosol droplets, which can rise to a height of approximately one meter above the toilet seat during flushing and disperse into the air. Each toilet flush can generate approximately 14,000 to 80,000 aerosol droplets, which may rise even higher if the water tank is installed at an elevated position or if a valve-type flushing system is used.

[0008] The droplets can rise to a height of approximately one meter. The study revealed that pathogens can be dispersed by aerosol droplets in the air emitted from toilet flushing, thus contaminating the washroom. Also, the smaller the size of pathogens, the higher their concentration in the air after flushing. Covering the toilet lid before flushing may help reduce airborne aerosol droplets containing bacteria that can contaminate the air and washroom. However, an international study by Professor Lai found that bacteria can still be emitted from toilet flushing when there is a space of several millimeters between the lid and the toilet bowl.

[0009] Multiple flushing attempts may not be effective in eliminating this problem. This is because pathogens can remain on the surface of the toilet bowl for some time and be transmitted by aerosol droplets. Therefore, when pathogens are dispersed into the air from a flushing event, the room walls and all surfaces and surrounding areas become contaminated. Consequently, the toilet lid, sink, and even the bathroom floor become contaminated. Recommended bleach or disinfectant solutions typically include regularly cleaning the toilet bowl with a 1:49 diluted household bleach solution and cleaning all bathroom areas with a 1:99 diluted household bleach solution. If available, using an exhaust fan for 15 to 30 minutes after using the bathroom can help weaken airborne bacteria and viruses. Opening windows also maintains adequate indoor ventilation.

[0010] In fact, a typical flush of a toilet fixture displaces air within the toilet bowl with additional water flowing into the bowl, returns air to the bowl with additional water flushed out of the bowl, and then displaces the air again after flushing. Typically, the aerosolized plume of biological material is pushed upward. However, the plume can also be pushed sideways when the toilet lid is closed due to gaps around the underside of the toilet lid and around the rim of the toilet bowl. Scientific findings that sewage can contain viruses and other pathogens, such as the SARS Covid-19 virus, support the idea that when an infected person uses a toilet fixture, these pathogens are present and can therefore be aerosolized into the immediate area of ​​the toilet, where they can then be deposited on virtually all surfaces in the immediate area of ​​the toilet.

[0011] Obvious problems with devices known in the art include their reliance on sensors, analyzers, collectors, filters, or disinfectants known in the art. Prior art devices are non-electrical, non-mechanical, and non-moving. Also, they are not airtight enough to prevent all aerosols. In addition to the above challenges, aerosolized or airborne contaminants, spores, or pathogens can slip around the edges of the illustrated products, which may only be retained within the housing and not sealed from the hollow space above and surrounding the toilet.

[0012] Therefore, what is clearly needed in the art is a modular anti-viral filter assembly for filtering displaced air from airborne contaminants during a cleaning sequence of a waste collection equipment, and for removing, containing, or eliminating inorganic and organic airborne particles, including the shedding of viral pathogens. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] U.S. Patent Application Publication No. 17 / 392,952 [Patent Document 2] U.S. Provisional Patent Application Publication No. 63 / 061,642 [Non-patent literature]

[0014] [Non-Patent Document 1] Wilcox, Sandoe, and Best, “Potential for Aerosolization of Clostridium difficile after flushing toilets” Summary of the Invention

[0015] According to an embodiment of the present invention, there is provided an anti-viral toilet bowl, the anti-viral toilet bowl including: a base structure having a toilet flush bowl and an upper rim; a toilet seat hinge mounted to the base structure and oriented concentrically with the upper rim; a toilet lid hinge mounted to the base structure and oriented concentrically with the toilet seat; a filter assembly including a high efficiency particulate air (HEPA) filter disposed in a porous metal filter track housing, the assembly mounted to the underside of the toilet lid concentrically with the toilet seat, the filter assembly making uniform surface contact at one end with an upper surface of the toilet seat when the toilet seat and lid are closed; and an electronics compartment having an interior volume for accommodating electronics for initiating flushing, a power source for powering the electronics, and at least one visual indication for status notification.

[0016] With the toilet seat and lid closed, a manually or electronically initiated flush sequence causes contaminated air within the toilet flush bowl to rise, pass laterally around the periphery, through the filter assembly, and be expelled outside the base structure as the water bowl is refilled from a connected water source.

[0017] In one embodiment, a hard-wired water tank serves as the water source and a flush button is provided in the electronics compartment to allow for manual flushing. In another embodiment, a hard-wired electronic flushing unit serves as the water source and flushing is initiated remotely via a wireless transceiver and remote power switch contained in the electronics compartment. In a variation of this embodiment, flushing is initiated when the closed state of the antiviral toilet bowl is optically detected. In another embodiment, flushing is initiated using the tank by a user operating a remote control device.

[0018] The toilet seat includes at least two linear, annular one-way check valves seated laterally through the material of the toilet seat, allowing outside air to enter the toilet bowl and preventing air inside the toilet bowl from returning to the check valve and escaping outside the base structure. In one embodiment, the visual indication includes two or more light-emitting diodes (LEDs) mounted on the exterior of the electronics compartment to alert the user to the status of the toilet bowl, including the status of the water filling within the toilet bowl after a flush action. In a preferred embodiment, the electronics for initiating flushing include a remotely activated power switch. In one embodiment, the electronics include a microcontroller with instructions for indicating the status via one or more LEDs.

[0019] In one embodiment, the antiviral toilet further includes an annular recess with a crossbar therein to act as a lifting handle located on the exterior of the electronics compartment. In one embodiment, the electronics further includes electronics for providing a negative charge to the interior track portion of the filter track housing and a positive charge to the exterior of the filter track housing. In one embodiment, the power source is a rechargeable battery, and the electronics further includes electronics for enabling the battery to be recharged. In a variation of this embodiment, the charging electronics is a universal serial bus (USB) port. In one embodiment, uniform surface contact between the top cover and the toilet seat is achieved via a gasket located on the free end of the filter assembly. In one embodiment, the antiviral toilet further includes a pair of polymer caps that cover the metal porous track housing at each end of the filter assembly. [Brief explanation of the drawings]

[0020] [Figure 1A] FIG. 1 is a front view of an antiviral toilet bowl with the lid down, according to an embodiment of the present invention. [Figure 1B] FIG. 1B is a front view of the antiviral toilet of FIG. 1A with the lid open. [Figure 2] FIG. 1 is a top perspective view of a toilet seat assembly for an antiviral toilet according to an embodiment of the present invention. [Figure 3] FIG. 1 is a bottom perspective view of a toilet seat assembly for an antiviral toilet, according to an embodiment of the present invention. [Figure 4] FIG. 1 is a front view of an improved CPAC filter for an antiviral toilet seat assembly, according to an embodiment of the present invention. [Figure 5] 1 is a cross-sectional perspective view of a toilet seat assembly for an antiviral toilet according to an embodiment of the present invention. FIG. [Figure 6A] FIG. 1 is a block diagram illustrating one of two antiviral toilets for use in public facilities, according to an embodiment of the present invention. [Figure 6B] 1 is a second antiviral toilet for use in public facilities according to an embodiment of the present invention. [Figure 7] 1 is a process flow diagram illustrating steps for using an antiviral toilet in accordance with at least one embodiment of the present invention. [Figure 8] FIG. 1 is a front view of an antiviral toilet with the lid raised, according to an embodiment of the present invention. [Figure 9] FIG. 9 is a top perspective view of the toilet lid and seat of the toilet bowl of FIG. 8. [Figure 10] 9 is a cross-sectional view of the HEPA filter assembly of FIG. 8 in accordance with an embodiment of the present invention. [Figure 11] 9 is a block diagram of the compartment of FIG. 8 and a remote device having wireless transmission capabilities. DETAILED DESCRIPTION OF THE INVENTION

[0021] In various embodiments described in as much detail as possible herein, the inventors provide a unique system for eliminating viral or pathogenic plumes emanating from a toilet bowl during flushing. A goal of the invention is to reduce, eliminate, or contain viruses or other pathogenic microorganisms, spores, and other contaminants in the air forced out of the toilet bowl during the flushing operation. Another goal of the invention is to prevent the unwanted spread of airborne viruses and other airborne contaminants to a group of people using the toilet facility. The invention will be described using the following examples, which may illustrate two or more related embodiments within the scope of the invention.

[0022] FIG. 1A is a front view of an antiviral toilet 100 with the lid down according to an embodiment of the present invention. The antiviral toilet 100 is a home version of the present invention. The toilet 100 includes a base structure 102 including a collection basin or bowl with a rim, as in all toilet systems. The toilet 100 includes a water tank 101 located behind the toilet 100 for holding water for flushing purposes. The toilet 100, in this embodiment, is manually flushed using a flush handle 103 connected to an internal chain, float, and stopper assembly typical of home toilet systems. As mentioned in the Background section of this specification, problems exist when flushing the toilet 100, regardless of whether the toilet lid is up or down, when flushing occurs, for example, when using the fixture by a person who may be shedding airborne pathogens, such as infectious airborne viruses. The problem is that the cleaning process releases water from the tank 101 into a bowl inside the base structure 102, thus causing air to move upward and outward and be expelled in a plume. Any airborne pathogens may be carried in the ejected plume for a significant period of time and may eventually, after a period of time, settle on surfaces near the fixture. In this case, some pathogenic agents may still retain the ability to infect another person who comes into contact with such bathroom surfaces after using the fixture.

[0023] In accordance with one embodiment of the present invention, the inventors provide an antiviral lid assembly 104 that can operate to reduce or eliminate pathogens that may be entrained in the moist air plume forced out of a toilet bowl flush during the process. The assembly 104 includes a donut-shaped toilet seat and lid that has been modified or otherwise manufactured to support an antiviral filter housing 105, which can be installed under the top lid and sealed against the inner edge of the modified donut-shaped seat that rests on the bowl rim of the base structure 102. In this embodiment, the donut-shaped seat can also be modified by adding gasket material on its underside to seal against the upper edge of the collection bowl inside the base structure 102. In one embodiment of the present invention, the assembly 104 can be manufactured and sold to purchasers as an after-sales antiviral solution to reduce or eliminate airborne pathogens that may otherwise escape the bowl mechanism, regardless of whether the toilet lid is in the raised or lowered position while flushing is occurring. In such cases, a purchaser may replace an existing toilet seat assembly with the antiviral toilet seat assembly 104. In this case, no modifications to other components of the toilet fixture 100 are necessary. In one embodiment, the top cover of the antiviral toilet seat assembly 104 includes a lifting handle that allows the user to conveniently raise and lower the top cover that supports the filter housing 105. In another embodiment, the filter housing 105 may be installed on an existing toilet seat assembly with any specific modifications necessary to successfully integrate the filter housing into the toilet seat assembly. In a preferred embodiment, the antiviral toilet seat assembly 104 is manufactured and added to an existing toilet fixture, replacing the old toilet seat assembly for the user's convenience. However, this is not particularly necessary to enable the present invention.

[0024] FIG. 1B is a front view of the antiviral toilet 100 of FIG. 1A with the lid open. In this view of the toilet fixture 100, the top lid of the antiviral toilet seat assembly is lifted, revealing the underside of the antiviral filter housing 105. The filter housing 105 may be molded from a polymeric material or polymer-rubber composite material of any density and weight, such as an acetal homopolymer material like Delrin™ or similar compounds. The filter housing 105 contains one or more antiviral air filters 106, in this case, three antiviral air filters 106. The antiviral air filters 106 may be continuous positive airway pressure (CPAP)-type antifungal / antiviral / antiparticle filters that may be modified for use as a filter array within the filter housing 105. It is noted herein that the underside of the filter housing 105 is not suitable for air to flow upwardly through it, except that it is intended for air to flow into and through the CPAP filter 106. It may also be noted herein that at least a portion of the filter housing 105 is hollowed out above the filter 106, allowing filtered air to exit the filter housing and flow through a side vent located at the rear of the housing; this vent is not shown in this embodiment, but its presence may be assumed. The improved CPAP filter may be considered a two-way filter, meaning that air can flow in both directions through the filter device. It is noted that during the cleaning process initiated by the handle 103, air may be pushed upward and out of the bowl as the bowl fills with water, and may be drawn back into the bowl as water drains through the bottom of the bowl during the cleaning process. More details regarding the improvement of the CPAP filter 106 will be provided later in this specification. Referring again to FIG. 1A, the filter housing 105 may extend below the donut-shaped toilet seat a certain distance from the geometric plane where the filter housing components seal against the inner edge of the donut-shaped toilet seat without departing from the spirit and scope of the present invention.In one embodiment, a handle may be provided on the top lid at the center front to assist the user in lifting the lid and attached filter housing away from the donut-shaped toilet seat.

[0025] FIG. 2 is a top perspective view of a toilet seat assembly 104 of an antiviral toilet 100 according to another embodiment of the present invention. In this embodiment, the antiviral toilet seat assembly 104 includes one or more improvements that may differ from the antiviral toilet seat assembly of FIGS. 1A and 1B. However, where the overall primary function of the assembly is the same, the same element numbers are given to the assembly and the filter housing. In this embodiment, the filter housing 105 is mounted to a toilet seat assembly top cover 200. The top cover 200 may have a molded configuration that overlies the filter housing 105 and overlies a donut-shaped seat 201, which is modified or otherwise formed to seal at its inner edge against the upper rim surface of the toilet bowl and in the form of a peripheral skirt 303 formed at an interior opening of the donut-shaped seat 201. The skirt 303 may be formed inward (toward the center) at approximately a 45-degree angle from the seat surface to match a sealing surface (not shown) that occurs on the outer lower periphery of the filter housing 105, which is complementary at a 135-degree angle and mates flush with the skirt 303 when the top lid 200 is fully lowered. In one embodiment, the seal is a surface-to-surface seal sufficient to eliminate any potential gaps between the filter housing and the donut seat. In one embodiment, an O-ring gasket may be provided between the filter housing 105 and the donut seat 201. Note further that the handle described above may assist the user in pulling the lid 200 up from the donut seat 201. In this embodiment, the donut seat 201 is modified or otherwise formed to include a geometric recessed feature 202 approximately at the top front center of the donut seat 201. The recessed feature 202 may function as a symmetrical crevice feature between the toilet seat 201 and the top cover 200, allowing the user to lift the top cover 200 without using a handle located on the top cover.

[0026] In this embodiment, the antiviral filter housing 105 may hold a single large-diameter antibacterial / antiviral filter 203 (logically represented by a dashed boundary). In this embodiment, the antiviral assembly 104 may be added for public facilities that are automatically cleaned using wireless sensor technology. In one embodiment, the antiviral toilet seat assembly 104, and more specifically, the antiviral filter housing 105, may include a wireless electronic control module (WECM) 204 that is adapted for near-field wireless communication with an automatic, all-electric flush unit that generates automatic flush commands based on sensor data provided by a user to describe a state or condition related to the toilet bowl and its operation. The top cover 200 includes an array of light-emitting diodes 205 adapted to notify a user about the state of the antiviral toilet bowl. In one example, flushing does not occur until the top cover 200 and antiviral filter housing 105 are closed and sealed to the donut-shaped toilet seat 201. In such cases, one or more conditions related to the antiviral toilet bowl may be incorporated into a flushing routine optimized for the antiviral toilet bowl. In a simple form, a red LED or multiple red LEDs may be on or flashing, preferably indicating that the flushing process has begun immediately after a user closes the lid 200 supporting the anti-viral filter housing 105 on the donut-shaped toilet seat 201. Without departing from the spirit and scope of the present invention, this action of closing the lid may be communicated to a charged powered flush unit (not shown) by flushing its respective toilet bowl in some manner.

[0027] In one embodiment, when a person leaves and closes the top cover before flushing, the powered flush unit uses an optical sensor to understand when the antiviral filter housing is properly in contact with the donut-shaped seat to initiate flushing. In another embodiment, when the top cover 200 is up, a trip sensor located near the hinge connection between the top cover and the donut-shaped seat communicates with the powered flush unit. An optical laser may be provided as the trip sensor, with a light beam blocked when the cover is up and unblocked when the uninterrupted cover is down. Further details regarding the flushing process are provided later in this specification. In one embodiment, the antiviral seat assembly includes a WECM 204 and / or an LED array 205, and a miniature power source (not shown), which may or may not be a rechargeable power source, may provide power electronics functions for the antiviral seat assembly 104. A miniature battery may be housed inside the antiviral filter housing 105. For rechargeable batteries, a charging port may also be provided for charging the power source. In one embodiment, an LED or pair of LEDs in LED array 205 may illuminate red when the battery is low and green when fully charged.

[0028] In one embodiment, one LED or pair of LEDs in the LED array 205 may illuminate red during flushing (lid opening prohibited) and green after flushing when it is safe to open the top cover 200. A counter may be used by the powered flush unit to precisely define the start and end of every toilet use session, particularly recording the raising and lowering of the top cover 200. In one embodiment, the powered flush unit may have a timer function to allow for realistic actions. For example, a user may not be able to open and close the top cover 200 quickly enough, expecting to initiate the flushing process every time the top cover 200 is closed. Similarly, a powered flush unit for a public toilet seat assembly 104 may include a fallback routine; for example, if a user simply walks away and does not close the top cover 200, the unit may initiate a flush after a set period if it detects that the top cover 200 is not closed and no person is detected in the stall or the immediate area around the public toilet seat assembly 104.

[0029] The top cover 200 includes multiple vents 206 (three vents are visible) located at the rear end and rear side of the unit. The vents 206 may each include several parallel through-slots that are located through the body of the top cover 200 and through the body of the filter housing 104 in the upper hollow portion of the housing above the top surface of the filter 203, or filter array 106 (home version) of FIG. 1B. It may be noted herein that any of the filter designs described above may be used in public facility versions of toilets or in residential versions of toilets without departing from the spirit and scope of the present invention. In a preferred embodiment of use, air pushed out of the toilet bowl during flushing is forced through the antibacterial air filter 203 into the hollow space above the filter, allowing the filtered air to be exhausted through the vents 206. Antibacterial filter 203 may be a two-way filter that allows air expelled through vent 206 when the bowl is drained during a flushing operation to be drawn back through filter 203 and expelled into the toilet bowl. Filter 203 may be removed and replaced as needed, preferably after approximately every six months of operation.

[0030] FIG. 3 is a bottom perspective view of the seat assembly 104 of the antiviral toilet 100 according to the embodiment of FIG. 1. In this embodiment, the filter design includes three CPAP filters in an array 106. The filters in the array 106 may be bidirectional positive airflow (BIPAP) filters, allowing air to flow through them in both directions to accommodate the two-way air displacement that occurs in the toilet bowl during the flushing process. The top cover 200 has a downwardly facing peripheral wall 301, which may be molded or otherwise formed and overhang the periphery of the donut-shaped seat 201 by a certain distance. The filter housing 105 may have a peripheral surface 306 formed at an angle complementary to the skirt surface 303, such that when these surfaces are brought together, they mate and are flush with each other to within a tolerance of about 1 degree or less across the entire mating surface, providing a sealed interface that eliminates the gap typically located between the top cover and the donut-shaped seat in prior art toilet seat assemblies that have not been modified to practice the present invention. In one embodiment, the sealing surface may include a circumferential groove feature 305 that may receive an O-ring gasket 304. The groove 305 may extend circumferentially near the angled surface of the skirt 306.

[0031] Surface-to-surface sealing techniques are well known in the art, and the desired sealing effect may vary depending on whether an O-ring gasket is provided. However, gasket sealing may allow for less strict angular tolerances when manufacturing the sloped interface between the inner skirt 303 and the sloped surface 306 around the bottom of the filter housing 105. In one embodiment, a toilet kit containing an antiviral toilet seat assembly may include two gaskets 300 and 306. In this embodiment, the donut-shaped toilet seat 201 has a flat, wide gasket 300 that is adapted to be adhered to the underside of the donut-shaped toilet seat and provide a seal against the upper surface of the toilet bowl rim. The gasket 300 may be adhered to the underside of the donut-shaped toilet seat 201. The gasket 300 may be a silicone rubber gasket material that is somewhat flexible yet resilient and has a thickness sufficient to provide a sealing surface against the toilet rim under the additional load of the top cover 200 caused by the addition of the filter housing. Gasket 300 eliminates the typical gap between the donut-shaped seat and the top rim of the toilet bowl, as found in unmodified toilets with seat assemblies not adapted to practice the present invention. Gasket 306 provides a similar seal between top cover 200 and toilet seat 201.

[0032] The purpose of using a gasket and / or sealing surface is to ensure that contaminated air from the toilet bowl does not escape into the atmosphere around the toilet bowl through any gaps in the system, but instead travels through the filter provided in the filter housing 105. It is noted herein that the top cover 200 should close on the donut-shaped toilet seat 201 against the rim of the toilet bowl as quickly as possible after the waste has been collected. The bidirectional nature of the filter and flushing process may also allow air that may escape before the lid is closed to be drawn back into the system during the flushing process, thereby significantly reducing, at a minimum, the number of contaminants in the air around the toilet bowl that would eventually settle on bathroom surfaces around the toilet bowl.

[0033] FIG. 4 is a front view of a CPAP filter modified for use with the toilet seat assembly 104 of the antiviral toilet 100, according to an embodiment of the present invention. The filter assembly 106 can be a CPAP or BIPAP filter modified to practice the present invention. The filter assembly 106 is adapted as a removable and replaceable filter inserted into an annular cavity provided through the bottom solid portion of the filter housing 105. An array of such filters can be provided, with each filter having its own airflow path. In the embodiment of FIG. 1B, there are three filters in the array. However, more or fewer filters may be incorporated into the filter housing without departing from the spirit and scope of the present invention. The filter 106 includes an annular polymer or plastic casing 400 having a disk-shaped central annular portion that houses a microbial / viral filter 402 (CPAP / BIPAP) and adjacent pre-filters 403, one above the filter material 402 and the other below the filter material 402.

[0034] In one embodiment, the pre-filter 403 may be fabricated from a cloth or plastic substrate with alternating concentric metal rings of zinc and copper separated by thin, uniform gaps. The zinc and copper may be printed or otherwise coated onto an annular substrate, which may be referred to as a nanoplate. The pre-filter 403 may also be referred to in the art as an electrostatic precipitator. An electrostatic precipitator may also include electro-sterilization functionality and be an annular insert within an otherwise unmodified CPAP or BIPAP filter assembly 106. The pre-filter 403 is adapted to remove bacteria during the inflow and outflow of airflow during the toilet flushing process. The gaps between the concentric zinc and copper rings (called nanoplates) allow an electrical current to be generated whenever ionic moisture is aerosolized during the toilet flushing operation, electrocuting bacteria, viruses, microorganisms, etc. within the resulting circuit.

[0035] The dust collector generates a weak electric field in the presence of moisture in the air moving through the CPAP or BIPAP filter device as described above. In addition to the filtering action of the central microbial filter material 402, the pre-filter 403 may eliminate airborne viruses at the contact points through a weak electrocution process. Zinc is a well-known antibacterial and antifungal compound, which, in the form of zinc pyrithione, may be incorporated into the fabric material, in this case in the form of rings. Copper salts may be used to form copper rings on the fabric material. Copper is often used in sterilization and has antibacterial properties. In one embodiment, the substrate for the zinc and copper rings may be plastic instead of fabric without departing from the spirit and scope of the present invention. In another embodiment of the present invention, the pre-filter 403 may include zinc and silver metal spots, silver instead of copper, in a dot matrix printed or otherwise coated on a mixture of fabric, fiber, plastic, or synthetic material, with silver dots connecting each copper spot in the matrix at the four corners. Essentially, the dot matrix functions similarly to concentric rings in the presence of ionized water or humidity in aerosolized water moving through the filter housing 105 (FIG. 1A). In one embodiment, the pre-filter 403 can be a virus-killing nano-copper disk that can be inserted into the filter casing.

[0036] The filter assembly 106 has a unique air flow path designed through the casing 400, which is open at both ends to facilitate airflow and includes an annular section 401 (a short pipe) at the top of the filter assembly. Section 401 empties the interior of the hollow portion of the filter housing 105 toward the rear of the housing, where the air vent 206, further introduced in FIG. 2 above, is located. During a flushing operation, the toilet bowl void fills with water, causing a plume of air to rise vertically through the filter assembly 106 in the direction of the arrow. As the air passes through the air flow path, it contacts the pre-filter 403 and the antibacterial / antiviral filter material 402. It is noted herein that after the plume rises due to pressure from the water filling the bowl immediately prior to flushing, the sudden removal of excess water from the bowl causes the airflow to reverse, causing filtered air and ambient air to flow back through the filter element 402 and again contact the pre-filter 403. Finally, the toilet bowl can be refilled to a predetermined depth immediately after flushing, again reversing the upward airflow so that airborne contaminants fully contact the pre-filter 403 and flow through the filter material 402 located approximately in the center of the vertical channel extending through the filter assembly 106. In one embodiment, the filter housing assembly 105 can include a small air fan that can be turned on during the flushing process and can help move the rising air through multiple filter channels or a single filter channel in the case of a single filter. Such a fan can be programmed to reverse the airflow into the toilet bowl at the correct time, as well as when water is drained from the bowl. The LED 205 (FIG. 5) on the top lid 200 can illuminate red at the start of the flushing process and then illuminate green for an appropriate period of time (5-7 seconds) after flushing, allowing the user to open the lid 200 and release the seal with the skirt 303 (FIG. 3) formed near the bottom of the opening in the donut-shaped toilet seat 201 (FIG. 3).

[0037] FIG. 5 is a cross-sectional perspective view of a toilet seat assembly for the antiviral toilet 104 of FIG. 3 according to an embodiment of the present invention. In this section view, the hollow portion of the filter housing 105 is visible. In one embodiment, the filter housing 105 and the top cover 200 are molded as a single, integral product. In another embodiment, the filter housing 105 is a separate product that is mounted to the underside of the top cover 200 in a manner that creates a hollow portion of the assembly. The bottom of the filter housing 104 is a thick material that supports a weight and also supports a complementary surface 306 (FIG. 3) (not shown in FIG. 5) that fits flush with the donut-shaped toilet seat 201 on the sloped skirt surface 303. The filter 106 is shown in this section with one filter casing disassembled to reveal the internal architecture for a step-by-step view of the filter element. In this view, a single air vent 206 is visible. A compartment 501 is provided in this embodiment to house a wireless control module, such as the WECM 204 of FIG. 2 above. In one embodiment, other electronics, such as a power LED 205 and / or a battery source for powering the WECM, are provided within the filter housing. In one embodiment, the WECM has an on-board power source in the form of a rechargeable battery. In a further embodiment, a charging port, such as a miniature universal serial bus (USB) port, may be provided for purposes of remotely charging the unit from an external battery or power source. In this embodiment, the hollow portion of the antiviral filter housing 105 extends the entire length of the housing, descending to the contact floor of the housing, and the annular CPAP filter is contained in a solid post that is open at both ends and configured so that the ends do not reach the full height inside the filter housing, allowing air to pass completely through the hollow portion of the filter housing.

[0038] In this embodiment, the gasket 300 seals against the upper rim of the toilet bowl, and the skirt extends below the rim of the toilet bowl. The recessed feature 202 may provide a convenient location for lifting the top cover 200, breaking the seal between the filter housing 105 and the donut-shaped seat 201. In a preferred embodiment, air may not pass from the toilet bowl into the filter housing 105 without traveling through a filter or filters. It may be envisioned that treated air may exit the filter housing 105 through a vent in the filter housing, such as vent 206. In this embodiment, the WECM may include an on-board battery that may also power the LED panel 205. The top cover 200, integrated with the filter housing 105, may be hinged at the rear to the donut-shaped seat 201 (hinges not shown). In one embodiment, the donut-shaped seat 201 may be made from a solid material, such as plastic, and may be molded or otherwise formed.

[0039] FIG. 6 is a block diagram illustrating an antiviral toilet 600 according to an embodiment of the present invention. The public facility 600 may include one, two, or more than two toilets 603, depending on the type of public restroom facility. In parking areas, there may be many toilets 603, while gas station facilities or parking lots and recreational facilities may have fewer toilets 603. In this embodiment, the public facility toilets are separated from each other by at least a partition 602 for privacy purposes. Each toilet 603 includes an antiviral toilet seat assembly 104 similar to assembly 104 of FIG. 2, and a single microbial / antiviral / antifungal filter 605 is provided in place of the improved CPAP / BIPAP filter. The filter 605 is supported by an annular air flow path, which may be several inches in diameter, similar to filter 203 introduced in FIG. 2 above. Similarly, the total footprint of the air flow paths of the three separate CPAP / BIPAP filters may total the same or several inches. Each public toilet 603 can be wirelessly paired with a dedicated, all-electric flushing unit 601. Tankless toilets flush directly through a water supply line (pipes not shown), as opposed to gravity-based tank systems that store gallons of water that drip into the toilet bowl. The flushing unit 601 can be equipped with smart sensor technology that flushes the toilet when the user leaves the optical recognition range of a step sensor, for example. However, to practice the present invention, flushing must be initiated. The toilet seat assembly 104 closes and seals to the donut-shaped seat, which in turn seals to the toilet bowl rim.

[0040] In one embodiment of the present invention, the flushing unit 601 is adapted to flush the toilet bowl 603 whenever the toilet seat assembly (top lid and antiviral filter housing) is closed and sealed. This may be accomplished using an optical sensor to determine when the assembly 104 (FIG. 2) is closed after use, prompting a hands-free flushing sequence that does not require the user to manually flush the toilet bowl. In this embodiment, one toilet bowl is shown with the assembly 104 in the up position. In this case, there is no command or sensed evidence to electronically flush the toilet bowl. The other toilet bowl is shown with the assembly 104 in the closed or up position. In this case, the WECM may send a wireless signal to the powered flushing unit to immediately initiate a hands-free flushing sequence. In more advanced embodiments, intelligence in the form of timing functions for toilet bowl 603 detection or communication state events may be provided to the all-powered flushing unit to mitigate errors in the flushing process. For example, it may occur that a user does not manually flush the toilet bowl and fails to close the assembly 104. In this case, backup routing may be observed, and if the user does not close the top lid on the donut-shaped toilet seat after a set period of time, the flushing unit 601 may temporarily override the closed assembly rule and flush the toilet with the lid open.

[0041] In one embodiment, an LED similar to LED 205 in FIG. 2 may be provided to indicate to the user that it is safe to open the toilet bowl top after the last flush sequence. Typically, the period is only 5-10 seconds long, ensuring that no airborne contaminants are still floating around the toilet bowl. In yet another embodiment, a servo unit may be provided that automatically closes the toilet seat assembly 104 on the donut-shaped toilet seat 201 (FIG. 2) via a hinged connection with a gas shock component, allowing for a smooth mechanical closing action and initiating flushing as soon as the flush unit is closed and sealed. In one embodiment, there may be a sleep mode for the battery-powered filter housing 104 that is activated to operate based on a sensor detecting a movement, such as a user lifting the assembly 104 in preparation for using the toilet bowl 603. The sensor may be located in the filter housing 105 or the powered flush unit 601 without departing from the spirit and scope of the present invention.

[0042] FIG. 7 is a process flowchart 700 illustrating steps for using an antiviral toilet according to at least one embodiment of the present invention. In step 701, a user opens the installed assembly by pulling up on the assembly top using a handle or ledge mechanism that releases the seal between the filter housing and the toilet donut seat. In step 702, it can be determined whether the toilet is a residential or community unit. If the unit is a residential unit in step 702, the user closes the top when finished and reseals the filter housing against the donut seat in step 703. In step 704, the user manually flushes the toilet using the provided flush handle. In this simple household routine, potentially contaminated air is filtered during the flushing process with the top closed. In one embodiment, the toilet has a timing function and LED panel that uses colored lights to notify the user when the top can be opened again.

[0043] If it is determined in step 702 that the toilet is not a residential version, it may be determined in step 705 whether the user is operating a community version of the antiviral toilet. If the toilet is a community toilet in step 705, the user closes the lid when finished in step 706. In step 707, the powered flush unit initiates a hands-free flush sequence. In one aspect, when the user opens the lid, the powered electronics present in the filter housing wake up from sleep mode and communicate with the powered flush unit to indicate that the user is operating the toilet, and the powered flush unit may apply a timing function to authenticate actual use of the toilet. In one aspect of a method for using a community version of the toilet, the timing function is used to flush the toilet with the lid open if the user forgets to close the lid after use and walks away. In one aspect of the community version of the toilet, one or more sensors are utilized to wake the toilet electronics from sleep mode when the toilet lid is lifted. In this aspect, again when the top cover is closed, a counter may be utilized to associate the opening and closing of the top cover with a usage session, and a timing function may authenticate the usage session. In one aspect using the public facility version, the top cover is mechanically controlled by a powered cleaning unit using a sensor and timing function to close the top cover if the user does not close it after use.

[0044] In one embodiment of the present invention, the inventors provide a system that utilizes an oval-shaped high efficiency particulate air (HEPA) filter housed in a conductive metal track housing mounted to the underside of a toilet lid. In this system, two or more one-way check valves are provided and installed horizontally through the toilet seat to allow room air to flow in only one direction into the toilet bowl during a portion of the flushing operation when the water level drops when the toilet is flushed. Also, in this embodiment, air from the toilet bowl is forced out horizontally through the HEPA filter and an opposing charged porous metal track housing section to optimize biological and particulate filtration of the forced out air and provide electronic disinfection of the airflow during the portion of the flush when the water level in the toilet bowl rises. This embodiment is described using the following example.

[0045] FIG. 8A is a front view of an antiviral toilet 800 with the lid raised, according to an embodiment of the present invention. The toilet 800 includes a base structure consisting of a toilet bowl 802 supported by foot formations 811 similar to the base structure 102, as described herein with respect to FIG. 1A of the parent application referenced above and incorporated herein. A water tank 801 is provided for holding flush water and is similar to the water tank 101 of the toilet 100 of FIG. 1A, except that in this example, a flush handle is not provided on the tank. In this example, a powered flush interface in the form of a flush button 814 is provided on top of an electronics compartment 805, which is integrated into or otherwise part of the toilet lid 803 shown above in this embodiment. The electronics compartment 805 may, in one embodiment, include a recessed lid lift bar 806 for manually lifting the toilet lid 803. In this embodiment, electronics compartment 805 does not hold any filters or filtration media, but is dedicated to housing at least one remote power switch electronics receiver 807 and one battery or set of batteries 824. In this embodiment, battery 808 may be a rechargeable or replaceable battery. The compartment housing battery 824 may include a microcontroller and may support an array of light emitting diodes (LEDs) similar to at least LEDs 205 described with respect to FIG. 2 of the parent application, which is incorporated herein by reference.

[0046] Compartment 805 may be accessible for maintenance purposes. Compartment 805 may be manufactured from the same material as toilet lid 803 or from a different material without departing from the spirit and scope of the present invention. In one embodiment, flush button 814 may be manually operated by pressing the button to flush toilet bowl 800. In the same embodiment, flush button 814 may also be remotely activated by a wireless signal. In alternative embodiments, flushing may be limited to manual or remote signal activation without departing from the spirit and scope of the present invention.

[0047] In this embodiment, an oval-shaped HEPA filter assembly 804 may be provided and centrally mounted on the bottom surface of the toilet lid 803 so as to be generally concentric with the electronics compartment 805 and the overall shape of the toilet lid. The HEPA filter assembly 804 may include a HEPA pleated filter 812 (shown in dashed lines). The HEPA filter 812, in this embodiment, is housed within an oval-shaped filter housing 813. The filter housing 813 may include inner and outer sections formed from a conductive metal that provides a porous cage or housing around the HEPA filter material. The filter housing 813 may include a polymer seat and polymer cap structure, which includes a central separator wall to separate and prevent the inner and outer section housings from touching. For example, the inner metal cage section forming the inner section and the outer metal cage section forming the outer section may be electronically charged (inner cage section: negative, outer cage section: positive) for the purpose of slightly increasing the antiviral effectiveness of the HEPA filter assembly beyond the effectiveness rating of the filter material itself.

[0048] In one embodiment, the HEPA filter assembly 804 can be sealed to the top of the toilet seat 815 via an oval rubber gasket 816. In one embodiment, a bottom polymer cap on the metal filter housing 813 is formed to create a surface-to-surface seal with the top of the toilet seat 815. In such an embodiment, airflow from the toilet can flow horizontally from inside to outside through the filter assembly and back through the filter assembly from outside to inside. In another embodiment, a semi-rigid rubber and / or polymer material is provided that is used in manufacturing toilet seats. In this embodiment, an airtight seal is formed using the soft / flexible material of the toilet seat.

[0049] In an alternative embodiment, a plastic housing similar to housing 105 may be provided, with vents installed to allow airflow in both directions. In this embodiment, the footprint of HEPA filter assembly 804 is larger than the footprint of the donut-shaped opening (vertical dashed line) through toilet seat 815.

[0050] In this embodiment, toilet seat 815 includes at least two linear, annular one-way airflow check valves, referred to herein as check valve 808a and check valve 808b. Check valves 808a and 808b allow outside air to flow into the toilet bowl but prevent air from backing out from inside the bowl and escaping to areas outside toilet bowl 800. It may be noted herein that outside air may flow freely through HEPA filter assembly 804 during flushing, while inflow occurs at the check valves. Check valves 808a and 808b are positioned through the material of toilet seat 815 and may range in diameter from ¼ inch to approximately ¾ inch. There may be more check valves 808 than are shown in this example without departing from the spirit and scope of the present invention.

[0051] Check valves such as valve 808a and valve 808b may be arranged at regular intervals and inclinations around the 360-degree perimeter of the toilet seat, anywhere around toilet seat 815, effectively. Check valves 808a and 808b may be electrically operated or may be mechanical spring and ball valves without departing from the spirit and scope of the present invention. In a preferred embodiment, check valves 808a and 808b open during a flush sequence, allowing outside air to flow through them and into the toilet bowl as the water level in the toilet bowl drops. In either an electronically controlled or manual (non-controlled) embodiment, airflow cannot flow back through the check valves from inside the toilet bowl at any time, as one-way valves are known in the art. Check valves 808a and 808b are not required to practice the present invention, but they do provide a mechanism for increasing airflow from the outside into the toilet bowl as the water drops during a flush.

[0052] In a typical use embodiment, the toilet bowl 800 can be used to collect waste. After collection, the user can close the top cover 803 against the toilet seat 815. The user can then flush the toilet bowl 800 by manually pressing the flush button 814 or by using a remote device and wireless signal to initiate a flush sequence. During flushing, the water in the toilet bowl drains and outside air can enter the toilet bowl through both the check valve and the HEPA filter assembly. The outside air entering through the filter assembly is sterilized by passing through the electrically charged filter housing and pleated HEPA filter. When water re-enters the toilet bowl, all of the displaced inside air is forced horizontally in all directions through the HEPA filter assembly and discharged outside the toilet bowl 800, where it is disinfected of microorganisms and particulates.

[0053] FIG. 9 is a top perspective view of the toilet lid 803 and toilet seat 815 of the toilet bowl 800 of FIG. 8. In this embodiment, the toilet lid 803 may be hingedly connected to the toilet seat 815 via a hinge bar set 823. The lid / seat assembly may be secured to the rear of the toilet rim of the base structure 802 shown in FIG. 8 above. The HEPA filter assembly 804 is shown necessarily secured to the underside of the toilet lid 803 (shown in dashed lines). The thickness dimension of the HEPA filter assembly 804 may be on the order of about ½ inch to about 2 inches. The height of the filter assembly 804 may be on the order of about ½ inch to about ⅝ inch. In a preferred embodiment, the bottom of the assembly 804 may conform to form a seal against the top surface of the toilet seat 815. In this view, the check valve 808b is visible and extends horizontally through the material of the toilet seat 815.

[0054] The lifting bar 806 may be annular and concave with a crossbar. A user may grasp the crossbar to pull the top lid 803 up and away from the toilet seat 815. In another embodiment, the lifting bar 806 is not present, and the user may lift the top lid 803 at the front center of the lid as further described above with respect to FIG. 5 of the material profile 202 of the toilet seat 201 in the parent application. Similarly, other handle types may be provided and mounted anywhere on the top lid 803 without departing from the spirit and scope of the present invention. The overall height of the electronics compartment 805 is appropriate to accommodate the electronic components and batteries and to hold the concave lifting bar mechanism 806.

[0055] FIG. 10 is a cross-sectional view of the HEPA filter assembly 804 of FIG. 8, according to an embodiment of the present invention. In this view, the HEPA filter 812 is housed within a porous metal track housing 813, which allows horizontal airflow through the negatively charged track section (inner track), pleated HEPA filter material, and positively charged track section in the direction of the arrows. When water is refilled into the toilet bowl after flushing, airflow in the direction of the arrows occurs, forcing air through the filter assembly. It is also noted herein that a reverse airflow may occur during periods when toilet water drips out of the toilet. In both cases, the air is disinfected as it passes through the filter assembly. In one embodiment, a polymer cap 1001 may be provided with an attachment and contact surface, preventing the metal of the track structure from contacting the underside of the top cover and the upper side of the toilet seat.

[0056] FIG. 11 is a block diagram of compartment 805 of FIG. 8 and a remote device with wireless transmission capabilities. In this view, compartment 805 includes a flush button 814, a lift bar 806, and a battery compartment 808. In this embodiment, compartment 805 includes a small microcontroller 1101 with a power switch accessible to the remote device. Microcontroller 1101 can be remotely activated to initiate a flush sequence for the toilet bowl. The automatic flush sequence can be initiated by a dedicated all-electric flush unit 1105, similar to flush unit 601 of FIG. 6 introduced above. Similarly, the automatic flush can be initiated by a handheld remote control 1104, which includes a battery for the electronics to generate a wireless signal and a button to transmit the wireless signal to a power switch receiver in compartment 805. Thus, the flush is initiated by pressing button 814 to activate the flush, or, in one embodiment, by remotely activating flush button 814.

[0057] The flush unit 1105 may include an optical sensor with line of sight to the toilet bowl top to determine, in real time, whether the toilet seat has been opened and then closed. This was described above with respect to unit 601. In one embodiment, automatic flushing may be implemented locally to the toilet bowl by adding an orientation sensor or other motion sensor to the electronics compartment 805, thus automatically detecting the position of the toilet bowl top for a session period associated with typical toilet use. The microcontroller 1101 may be connected to the battery 808, the flush button 814 (if controllable using signals), and the array of LEDs 1102 (which may be similar to the description of LED 205 in FIG. 2 above) using a bus structure or simple electrical paths (logical dotted lines). In one embodiment, an LED selection module 1103 may be provided to allow the microcontroller to select, via firmware routines, which of the array of LEDs to illuminate. In one embodiment, the batteries or one battery in the compartment 808 are rechargeable, and a universal serial port (USB) may be provided for charging the battery or batteries. One or more LEDs 1102 may be dedicated to indicating charging status. One or more LEDs may be dedicated to activating states such as when the lid is closed, when a flush sequence is in progress, and when the toilet bowl can be reopened for the next session. In a preferred embodiment, this period will last from the moment water re-flows into the bowl (indicated by one color) until the water level in the bowl is again at its highest point (indicated by another color) before the next use. And many different possibilities exist.

[0058] It will be apparent to those skilled in the art that the antiviral toilet system of the present invention can be provided using some or all of the elements described herein. The arrangement of elements and their functions with respect to the present invention are described in different embodiments, each of which is an embodiment of the present invention. Although the application and method are described in as much detail as possible herein, it should be noted that many modifications can be made to the details of the structure and arrangement of elements without departing from the spirit and scope of the present invention. The present invention is limited only by the scope of the following claims.

Claims

1. An antiviral toilet, a base structure including a toilet bowl having an upper rim; a toilet seat hinge mounted to the base structure and oriented concentrically with the upper edge; a toilet lid hinge mounted to the base structure and oriented concentrically with the toilet seat; a filter assembly including a high efficiency particulate air (HEPA) filter disposed within a porous, metallic filter track housing, the assembly mounted to the underside of the toilet lid concentric with the toilet seat, the filter assembly making uniform surface contact at one end with an upper surface of the toilet seat when the toilet seat and lid are closed; an electronics compartment having an interior volume for housing electronics for initiating cleaning, a power source for powering the electronics, and at least one visual indication for status notification; 1. An antiviral toilet bowl, wherein, with the toilet seat and lid closed, when the water bowl is refilled from a connected water source through a manually or electronically initiated flush sequence, contaminated air within the toilet flush bowl rises, passes laterally through the filter assembly along the periphery, and is discharged outside the base structure.

2. 10. The anti-viral toilet of claim 1, wherein a plumbed water tank serves as a connected water source and a flush button is provided in the electronics compartment to allow manual flushing.

3. 10. The antiviral toilet of claim 1, wherein a plumbed electronic flushing unit serves as the connected water source and flushing is initiated remotely via a wireless transceiver and remote power switch contained in the electronics compartment.

4. 4. The anti-viral toilet of claim 3, wherein flushing is initiated when the closed state of the anti-viral toilet is optically detected.

5. 3. The antiviral toilet of claim 2, wherein flushing is initiated by a user operating a remote control device.

6. 2. The anti-viral toilet bowl of claim 1, wherein the toilet seat includes at least two linear, annular one-way check valves that penetrate the material of the toilet seat and seat laterally, the check valves allowing outside air to enter the toilet bowl and preventing air inside the toilet bowl from returning to the check valves and escaping to the outside of the base structure.

7. 10. The anti-viral toilet bowl of claim 1, wherein the visual indication comprises two or more light-emitting diodes (LEDs) mounted on the exterior of the electronics compartment to alert a user to the status of the toilet bowl, including the status of the water filling in the toilet bowl after a flush action.

8. 10. The antiviral toilet of claim 1, wherein the electronics for initiating flushing include a remotely activated power switch.

9. 10. The antiviral toilet of claim 1, wherein the electronics include a microcontroller having instructions for indicating a status via the one or more LEDs.

10. 10. The antiviral toilet of claim 1, further comprising an annular recess having a cross bar therein to act as a lifting handle located on the exterior of the electronics compartment.

11. 10. The anti-viral toilet of claim 1, wherein the electronics further include electronics for providing a negative charge to an interior track portion of the filter track housing and a positive charge to an exterior of the filter track housing.

12. 10. The anti-viral toilet of claim 1, wherein the power source is a rechargeable battery, and the electronics further include electronics for enabling the battery to be recharged.

13. 13. The antiviral toilet of claim 12, wherein the charging electronics is a Universal Serial Bus (USB) port.

14. 2. The antiviral toilet bowl of claim 1, wherein the uniform surface contact between the top cover and the toilet seat is achieved through a gasket installed at a free end of the filter assembly.

15. 10. The antiviral toilet of claim 1, further comprising a pair of polymer caps covering the metal porous track housing at each end of the filter assembly.

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