RESPIRATORY PUMP ARRANGEMENT FOR PERSONAL RESPIRATORY ISOLATION AND METHOD OF USE

A personal respiratory isolation assembly includes a manifold-filter assembly configured to be attached to a suction port of a respiratory pump. The manifold-filter assembly has a bowl-shaped manifold housing with an inlet adapter configured for connecting a hose, and a filter releasably attachable to the manifold housing. The isolation assembly further comprises an exhaust baffle with a plurality of openings. The exhaust baffle fits a pressure port of the respiratory pump. A method of operating a personal respiratory isolation assembly involves attaching an exhaust baffle to an outlet adapter of a respiratory pump; connecting a manifold housing to a suction port of the respiratory pump with a filter disposed between the manifold housing and the suction port; connecting a hose to an inlet adapter of the manifold housing; attaching the hose to a hose port of a hood; and starting to operate the respiratory pump.

TECHNICAL FIELD

The present disclosure deals with equipment for preventing exhaled pathogens from entering the surrounding atmosphere. In particular, the present disclosure deals with a pump-operated device for filtering exhaled air before the exhaled air enters the surrounding atmosphere.

BACKGROUND

Patients with infectious respiratory diseases exhale pathogens into the environment. These pathogens may be contained in droplets of such a small size that they remain airborne for an extended period of time, thereby posing a great risk of infecting other individuals inhaling the air in the vicinity of the infected patients.

Protective multi-layer face coverings, including medical masks, provide varying degrees of filtering, but breathing through multiple layers may become burdensome, especially for weakened patients.

Further, personal pump-aided respirator systems have been suggested for protecting a healthy wearer from surrounding airborne pathogens by pumping filtered air into a helmet to create a pressure increase in the helmet that prevents an influx of contaminated air through gaps around the helmet. One example of such a pump-aided respirator system is disclosed in US 2009/0314295 A1, which discloses a pump housing defining an air inlet and an air outlet; a filter assembly covering the air inlet of the housing for removing contaminants from air passing therethrough; an impeller/motor assembly contained within the housing for drawing air through the air inlet and through the filter and expelling the air through the air outlet; and various internal pump components. The pump housing defines a generally cylindrical body enclosing an interior space with a diameter greater than the axial length of the interior space. The air inlet is formed in one axial face of the pump housing and has a cross-section that is commensurate with the interior space of the cylindrical body. The air outlet extends in a tangential direction away from the cylindrical outer wall of the cylindrical body and has a cross-section that is significantly smaller than the cross-section of the air inlet. Further, the air outlet features a threaded adapter for connecting a respiratory hose.

It is further known to build negative-pressure rooms with air pumps removing potentially contaminated air from the room through effective filters so that a vacuum is created that prevents the contaminated air from escaping through other openings, e.g. a temporarily opened entry sluice. Negative-pressure rooms provide about 12 air changes per hour; that is the room air is refreshed every 5 minutes to reduce the contaminated air in the room to protect health care workers from pathogens exhaled by infected patients. Negative-pressure rooms, protect healthcare workers as long as patient remains in the room and thus restrict patient's movements, even if the patient is otherwise ambulatory. Only a limited number of such negative pressure rooms exist even in large well-resourced hospital settings as they are expensive to build.

These measures may be suitable for some situations, but it would be desirable to enable access to an infected patient or transport the patient to test equipment such as a CT-scan without exposing the healthcare provider to the exhaled pathogens and without impeding the mobility and vision of the patient or the health care provider, while allowing the patient to breathe freely or allow visitation without endangering the visitors.

SUMMARY

The present disclosure discusses a personal respiratory isolation assembly comprising a manifold-filter assembly configured to be attached to a suction port of a respiratory pump. The manifold-filter assembly has a bowl-shaped manifold housing with an inlet adapter configured for connecting a hose, and a filter releasably attachable to the manifold housing. The personal respiratory isolation assembly further comprises an exhaust baffle with a plurality of openings. The exhaust baffle is configured to be attached to a pressure port of the respiratory pump. This arrangement converts a respiratory blower into a respiratory vacuum pump.

For facilitating the use of existing equipment, the manifold-filter assembly is preferably configured for retrofitting commercially available respiratory pumps.

Likewise, to facilitate the conversion, the exhaust baffle may comprise a connector portion complementary to the inlet adapter of the manifold housing and capable of forming a mated connection with the inlet adapter. This allows for the use of the same types of hoses as customary for conventional applications.

The exhaust baffle is preferably cup-shaped and the plurality of openings of the exhaust baffle includes openings extending outward in different directions for preventing an obstruction of the exhaust baffle if the assembly is placed on or beside a patient bed.

For optimizing the function of the manifold-filter assembly, the manifold housing preferably has a manifold diameter and a manifold depth, wherein the manifold diameter is greater than the manifold depth. Additionally or alternatively, the inlet adapter has a diameter of a size smaller than or equal to the manifold depth. Further, the bowl-shaped manifold housing may include a cylindrical wall and the inlet adapter may surround an opening in the cylindrical wall.

The filter may include a ring-shaped filter frame and a filter substrate held by the filter frame, wherein the filter frame is configured for being attached to the manifold housing and to the suction port.

A removable plug insert dimensioned to form a seal with the inlet adapter while the personal respiratory isolation assembly is not in use prevents contamination of environmental air with particulates present in the manifold housing..

The personal respiratory isolation assembly may further include a respiratory pump with a pump motor operable to draw air through the inlet adapter and the filter and to expel the air through the exhaust baffle. This is especially beneficial where no respiratory pump is available for being retrofitted.

The hose is preferably equipped with a coupling portion configured to mate with the inlet adapter of the manifold housing.

The personal respiratory isolation assembly may further comprise a hood dimensioned to be placed on a human head, the hood including a clear face shield defining a front area behind the face shield, pliable sides, a pliable top, a hose port , and an internal support structure arranged between the hose port and the front area covered by the face shield, the internal support structure configured to facilitate and air flow from the front area to the hose port.

The internal support structure comprises a porous material, which is a low-cost, highly functional solution, especially if the internal support structure comprises reticulated foam.

An elastic seal disposed along edges of the hood prevents contaminated air to leak out of the hood and also inhibits the entry of environmental air into the hood along the edges of the hood.

Instead, below the face shield, a chin portion comprising breathable material may be disposed to allow air to enter the hood through the chin portion. The chin portion may include filter material for filtering the air entering the hood through the chin portion.

A method of operating a personal respiratory isolation assembly involves the following steps of attaching an exhaust baffle to an outlet adapter of a respiratory pump; connecting a manifold housing to a suction port of the respiratory pump with a filter disposed between the manifold housing and the suction port; connecting a hose to an inlet adapter of the manifold housing; attaching the hose to a hose port of a hood; and starting to operate the respiratory pump.

After conclusion of the operation of the pump, the method may further include the step of inserting a plug insert into the inlet adapter of the manifold housing to form a seal for containing particulates in the manifold housing after the respiratory pump is turned off, thereby creating a particulate-sealed chamber upstream of the filter.

Further details of the present disclosure will be apparent from the following description of the appended drawings. The drawings are provided herewith solely for illustrative purposes and are not intended to limit the scope of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference toFIG. 1, a personal respiratory isolation assembly10includes a respiratory pump12, a filter14(shown inFIG. 2) in communication with a manifold housing16, e.g. a manifold-filter assembly18composed of the filter14and the manifold housing16, an exhaust baffle20(shown inFIG. 2), a personal hood22with face shield52that is preferably transparent throughout most of its area, and a hose24for communicating air exchange between the hood22and the manifold housing16.

The respiratory pump12may be configured like the respiratory pump disclosed in US 2009/0314295 A1. It is, however, not critical to use the same pump. Any respiratory pump is adaptable for the purposes of the present disclosure with the additional equipment described below. The present disclosure is rather based on the general concept to reverse the air flow through the hose24that connects the respiratory pump12with the hood22.

This becomes evident fromFIG. 2. Instead of connecting the hose24to the pressure port26of the respiratory pump12, the exhaust baffle20is configured to be connected to the pressure port26of the respiratory pump12. For this purpose, the exhaust baffle20includes a connector portion28that is dimensioned to mate with the outlet adapter30at the pressure port26of the respiratory pump12, which, in customary applications, is typically used for connecting a respiratory hose. In the shown example, the connection between the outlet adapter30of the respiratory pump12and the exhaust baffle20is threaded. As shown in the example provided, the connector portion28of the exhaust baffle20features an external thread that corresponds to a customary external thread forming a coupling portion32at the end of a respiratory hose24, and the outlet adapter30of the pressure port26of the respiratory pump12features an internal thread complementing the external thread of the exhaust baffle20.

If a different pump with a different type of outlet adapter30is used that fits a different coupling portion32of a hose24, the connector portion28of the exhaust baffle20is adapted to fit the outlet adapter30of the respiratory pump12, corresponding to the coupling portion32of a hose24suited to be attached to the different type of outlet adapter24. Such a modification may, for example, involve a reversal of inner and out threads or a bayonet connection.

The exhaust baffle20is cup-shaped with a plurality of openings34in different directions as shown inFIGS. 2 and 5. The openings34extending in different directions preferably include a plurality of openings34circumferentially distributed around the cylindrical wall of the exhaust baffle20. at least one of the openings34is preferably disposed in the end face of the cup-shaped body of the exhaust baffle20opposite from the connector portion28. Each of the openings34has a diameter A of at least 0.5 cm, preferably at least 1 cm. The arrangement of these openings34prevents accidental blocking of the exiting air when in use because, even if all but one of the openings34are obstructed by a material, air can still be exhausted at a targeted flow rate. It is thus possible to place the respiratory pump12on or beside a patient bed (or it can be worn by the patient with an attached belt for mobility as the pump motor runs on a rechargeable battery) without the risk that the pressure port26of the respiratory pump12is blocked by bedding material. If the outflow is blocked or if the filter is clogged, a standard flow sensor incorporated into the pump system (not shown here) would trigger an alarm.

Referring toFIG. 2again, the suction port36of the respiratory pump12is fitted with the manifold-filter assembly18composed of the filter14and the manifold housing16. The manifold housing16is bowl-shaped, with a diameter D greater than is depth Z. The bowl-shaped manifold housing16as shown has an internally domed bottom38and a circumferential, generally cylindrical wall40with an inlet adapter42configured to receive the coupling portion32of the hose24. It is not crucial that the bottom38of the bowl-shaped manifold housing16is domed because a respiratory pump12does not create extreme pressure differences that would require stabilizing vaulted or domed structures. Any vacuum forces generated by a customary respiratory pump12can be withstood by a manifold housing16made of a hard plastic of appropriate thickness, even with a flat bottom38. In the shown example, the bottom38of the bowl-shaped manifold housing16has a flattened end surface44on the outside, which facilitates the attachment of a label with, for example, warnings, instructions, or a company logo.

The depth Z of the manifold housing16is at least equal to the diameter d of the inlet adapter42to ensure that the inflowing air entering from the hose24is able to spread over the entire cross-section of the interior cavity of the manifold housing16(see alsoFIGS. 3 and 4). These proportions provide an optimized utilization of the area of the filter14, which is removably attached to the manifold housing16.

The filter14includes a ring-shaped filter frame46adapted to the shape of the cylindrical wall40of the manifold housing16as shown inFIG. 2. The filter frame46holds a filter substrate48extending over the entire open cross-section of the filter frame46. The filter substrate48is chosen to capture targeted materials, such as airborne particulates, including pathogen-loaded droplets and aerosols. In one example, the filter substrate48is constructed as a HEPA filter substrate48. Air exiting the manifold housing16via the filter14toward the respiratory pump12is therefore purified before entering the internal portions of the respiratory pump12.

In a preferred embodiment, the inlet adapter42of the manifold housing16is identical to the outlet adapter30of the respiratory pump12so that the hose24may be used in a conventional arrangement (attached to the pressure port26of the respiratory pump12) and also with the manifold housing16(at the suction port36of the respiratory pump12). The difference lies in the flow direction of the air flowing through the hose24. In this preferred configuration of the inlet adapter42, the connector portion28of the exhaust baffle20and the inlet adapter42of the manifold housing16complement each other and are capable of engaging in a mating connection.

The manifold housing16is also equipped a plug insert50for sealing the inlet adapter42when not in use. This plug insert50seals contaminants inside the manifold-filter assembly18and prevents contamination of the surrounding atmosphere after use. The plug insert50may be threaded to sealingly mate with the thread of the inlet adapter42. Alternatively, the plug insert50is made of elastomeric material creating a radial or an axial seal—or both—when pressed into the inlet adapter42. Because the plug insert50is only in use when the respiratory pump12is turned off, it does not need to withstand the vacuum forces generated by the operation of the respiratory pump12.

As seen inFIG. 1, the hose24leads to a pliable hood22, comprising a clear face shield52, pliable sides54and top56, a hose port58near the top56of the hood, remote from the face shield52, and a shape-conforming elastic seal60extending along its edges and adapting to the contours of a person's head when worn. Furthermore, the hood22includes an internal support structure62arranged along the top56of the hood22between the hose port58and a front area covered by the face shield52as illustrated inFIG. 5.

The pliable sides54and top56of the hood22are made of a soft textile or plastic material, to which the clear face shield52is attached. The clear face shield52may be a shape-retaining clear plastic material that need not be rigid and may be, at least to a degree, bendable to adapt its lateral sides64to the shape of a patient's head. As visible inFIG. 1, the hose port58for attaching the hose24is positioned near the top56of the hood22at a distance from the clear face shield52toward the rear of the hood22. Preferably, the connection of the hose24with the hose port58is releasable.

With the hose port58remote from the face shield52, the view through the face shield52is unobstructed. Because air is exhaled in the vicinity of the face shield52, however, a flow path for the exhaled air through the hood22from the front area66in the vicinity of the face shield52to the top of the hood22needs to be ensured. Thus, the internal support structure62at the top56of the hood22serves two purposes. It prevents a collapse of the pliable hood22, even under suction. The support structure62further provides an air flow path along the top56of the hood22from the front area66behind the face shield52to the hose port58and thus facilitates the movement of exhaled air from the front area66through the hose to the manifold-filter assembly18.

The support structure62, best seen inFIG. 5, may have air channels formed on its surface or internally. A low-cost solution consists in forming the support structure62from a sheet of reticulated polyurethane foam with a pore size of about 10 ppi to about 20 ppi. The sheet of reticulated foam may have a thickness in the range of about 2 cm though 5 cm. Reticulated foam is made from closed-cell foam or open-cell foam by removing the walls between foam cells in a thermal or chemical process. This leaves behind a three-dimensional skeleton of webs68that allow a nearly free flow of air through the support structure while providing a firm support for the hood22. Alternatively or additionally, the support structure62may include unreticulated open-pore foam, a flexible plastic body, a wire support structure or one or more tubes.

A chin portion70of the hood22, extending below the face shield52, between the face shield52and the seal, is preferably made of breathable material for allowing air to enter the hood22. This may be accomplished by providing openings72in the chin portion70below the face shield52. Alternatively or additionally, the breathable material may be formed by or with a filter material, e.g. a HEPA filter, suited for purifying air entering the hood22. For that purpose, a filter pocket74may be formed by the chin portion70with the openings72in the chin portion70providing a flow path for the filtered air entering the interior of the hood22.

In particular with the use of the filter material in the chin portion70, the seal60along the edges of the hood22serves the purpose of closing off alternative pathways for air entering the hood22. That way, all, or at least over 90% of the air entering the hood22is purified. If the seal60along the edges of the hood22allows a small amount of unfiltered air to enter the interior space of the hood22, the suction applied to the hose port58directs the entering air towards the hose port58, away from a wearer's nose or mouth.

The equipment described above is configured for carrying out a method for preventing air containing particulates from contaminating the environment and also optionally from contaminating the interior space of the hood22while being worn with the filter material inserted in the chin portion70. The hood thus helps protect health care workers from inhaling contaminated air exhaled by the patient when the hood22is worn by a patient with infectious respiratory disease and also protects the patient from inhaling contaminated air from the environment. Conversely, the hood22may also be worn by a healthcare worker to protect patients from inhaling contaminated air exhaled by the healthcare worker.

The method involves attaching the exhaust baffle20to the outlet adapter30of the respiratory pump12, connecting the filter14to the manifold housing16to form the manifold-filter assembly18; connecting the manifold-filter assembly18to the suction port36of the respiratory pump12; connecting the hose24to the inlet adapter42of the manifold housing16; attaching the hose24to the hose port58near the top56of the hood22, and starting to operate the respiratory pump12.

The respiratory pump12draws air from the hood22through the hose24and through the manifold-filter assembly18, and expels the filtered air through the exhaust baffle20. When the hood22is placed on a patient's head, the support structure62inside the hood22provides an air flow path from the front area66behind the face shield52to the hose port58near the top56of the hood22.

After use, for containing particulates from contaminating the environment, the method involves inserting a plug insert50into the inlet adapter42of the manifold-filter assembly18to form a seal after the respiratory pump12is turned off, thereby creating a particulate-sealed chamber upstream of the filter14.

While the above description pertains to the preferred embodiments of the present invention, the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.