GB2593928A - Hood - Google Patents

Abstract

A hood 12 to be worn over the head and protect a wearer from airborne matter and aerosols, such as viruses, comprising a barrier 22 for enclosing the head, formed at least partly of transparent, flexible sheet material; a structure 46 to permit connection of a hose from a clean air supply; and a cuff 24 around a lower edge of the barrier to sit against the wearer’s neck. Preferably the cuff is formed of a permeable material to allow egress of air whilst still filtering pathogens, in which case positive pressure within the hood, from the air supply, can prevent ingress the same way. Preferably there is a dedicated through-passage in the cuff (figure 6) for insertion of the hose and a retaining means 48 to hold it in place. The hood may be provided as part of a respiration system (figure 2) with a powered filtration and air source 14, connected via hose 18 to noise attenuation unit 16 to mitigate fan noise in the hood and then connected to the hood via hose 20.

Description

HOOD

FIELD

The present teachings relate to a hood, particularly, but not exclusively, a hood to provide physical protection against infection from viruses and the like. In addition the present teachings relate to a respiration system including hood.

BACKGROUND

Various forms of personal protection equipment (PPE) are known for use by healthcare professionals and other people coming into contact with potential carriers of infectious diseases, such as those caused by viruses. To a greater or lesser extent the equipment aims to prevent the virus coming into contact with the mucous membranes of eyes, nose and mouth as these are the most common entry points for infection.

However, the present inventors have recognised, not least due to experiences in the coronavirus (covid-19) pandemic, that current PPE has a number of shortcomings that makes its use in healthcare settings and elsewhere sub-optimal for both the professionals and the patient.

At one end of the spectrum the use of masks and visors provide multiple junctions where viruses can bypass the protection and reach a mucous membrane, particularly if accidentally dislodged or improperly fitted. In addition, the equipment is uncomfortable and sweaty, impairs communication and visibility, and when being doffed, creates a further risk of an infectious pathogen passing from the equipment itself into in particular the eyes of the wearer. There are also additional problems for certain classes of users, such as those that wear glasses or have beards/moustaches. Further, donning and doffing may have to occur regularly if a professional is seeing multiple patients or needs refreshment and toilet breaks, which reduces their productivity and further increases risks.

In addition this type of PPE can be intimidating for the patient as it prevents good communication and looks visually imposing. It may also not be effective at preventing a wearer who unknowingly has a particular disease from accidentally infecting the patient or their fellow workers.

At an opposite end of the spectrum are fully enclosed suits that offer effective protection, but are often uncomfortable, provide poor visibility, mobility, are very costly to supply and very time-consuming to don and doff.

In addition hoods are known in industrial environments for use in welding, and paint spraying, but are prohibitively expensive, offer restricted fields of view and are not concerned with the capture of material expelled from the hood.

The present teachings seek to overcome or at least mitigate the problems of the prior art. 5 SUMMARY A first aspect of the present teachings provides a hood for wearing over a head of a user to provide protection against airborne matter such as virus containing aerosols and the like; the hood comprising a barrier enclosing the head and formed at least partially of transparent flexible sheet material, a structure to permit the connection of a hose thereto from a clean air supply, a cuff arranged around the lower edge of the barrier to sit against a neck of the user, optionally wherein the cuff is formed at least partially of a permeable material so as permit egress of air whilst capturing aerosols and/or particles therein.

The flexible barrier material prevents the direct transfer of contaminated matter onto the skin of the user via airborne transfer or physical contact. Further by being able to supply clean air into the hood, a positive pressure is generated that inhibits the seepage of contaminated airborne matter past the barrier, as well as supporting respiration of the user, performing a cooling function and inhibiting the build-up of condensation on the interior of the hood. The cuff of permeable material provides a route for the controlled egress of air from the hood, to help maintain the positive pressure, but also may act to filter out at least a proportion of aerosols and/or particles in the air that is vented. This may be particularly important if the wearer is infected with a transmissible disease, so as to reduce the risk of the wearer spreading the disease to others. Further such a hood may be constructed at low cost and without specialist equipment or tooling, and so can be disposable. Hoods of this type also allow users to wear spectacles, hard hats or other PPE without them interfering with use or efficacy of the hood. Further a hood is secure and therefore not easily dislodged. However when being removed, there is less risk of infectious material being accidentally being brought into contact with the user's mucous membranes.

Optionally, the permeable material is a flexible sheet material.

This allows the permeable material to conform to the shape of the user's neck and to be readily attached to the barrier Optionally, the cuff comprises an adjustment mechanism, e.g. a hook and loop fastener, buckle, elasticated and/or drawstring arrangement.

This provides a better fit without needing complex, bespoke adjustment structures Optionally, the cuff comprises the structure for connection of the hose.

This provides a simple structure that does not, for example, require a fitting to be welded to the hood to mount the hose and allows the hose to be connected at the base of the hood where it does not impair mobility.

Optionally, the structure comprises a discrete through-passage formed in the cuff for the insertion of the hose therein.

This further simplifies the arrangement with a passage being formed e.g. by stitching or bonding overlying parts of the cuff to form a passage into the hood of appropriate size for a hose.

The through-passage may extend from the bottom to the top of the cuff, Such a passage may be formed by may be a simple linear bonding or stitching operation to form a separate portion of the cuff from the major portion that receives the neck of the user Optionally, the structure further comprises retainer mechanism to hold the hose within the through passage.

After insertion it is important for the hose to be held in place securely so it is not accidentally dislodged when in operation Optionally, wherein the retainer mechanism comprises a flexible cord, tie, strap, webbing or ribbon arrangement.

Such arrangements can be tied or otherwise secured around the hose to hold it in place within the passage. They are not complex to manufacture and are low cost.

Optionally, the permeable material is a fibrous material.

Fibrous material is typically low cost, effective, and comfortable to wear.

Optionally, the cuff is formed of a woven or non-woven fibrous material, e.g. woven thread material such as cotton, wool, polyester or the like.

Such materials are readily available and may provide the required combination of permeability and capture of aerosols and particulates.

Optionally the cuff is formed from at least 50% permeable material, optionally being substantially entirely of permeable material.

Optionally, more than 50%, optionally more than 70% or optionally more than 90% of a surface of the barrier is formed of transparent flexible sheet material e.g. polyvinyl chloride.

This provides good all-round visibility for the user at low cost. It also allows people interacting with the wearer to have a good view of the user's facial expressions. Also such material is able to transmit sounds well in both directions, further aiding communication.

Optionally, substantially all of the barrier is formed of transparent flexible sheet material.

This further aids visibility and may at the same time simplify manufacture by not requiring additional joints or seams between different materials. It further avoids the user's face being shaded, which may be problematic in certain circumstances.

Optionally, the barrier further comprises a port for the insertion of a straw.

This enables the user to consume liquid refreshments and food without needing to remove the hood. The positive pressure means that any airflow is away from the user, but a flap or adhesive cover may nevertheless be used to selectively close the port.

A second aspect of the present teachings comprises a respiration system comprising a hood according to the first aspect and an air delivery unit This provides a complete system to protect the user.

Optionally, wherein the air delivery unit comprises a TH2 or TH3 level, or equivalent standard, filter.

Such a filter captures aerosols and particles that may carry viruses or other pathogens so they are not transferred into the hood.

Optionally, a hose connects the filter to the hood, optionally the hose being ribbed.

A ribbed hose allows its secure retention to the cuff using a simple retainer mechanism.

Optionally, the air delivery unit further comprises a fan and energy storage device, such as a battery, arranged to power the fan.

This enables the air delivery unit to be body worn, further enhancing the usability and mobility of the system.

Optionally, a sound attenuation device is provided upstream of the hood.

This further enables verbal communication to and from the user by minimising the operating noise of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are now disclosed by way of example only with reference to the drawings, in which: Figure 1 is a front view of a user wearing a hood and respiration system of the present teachings; Figure 2 is a side view of the user wearing a hood and respiration system of the present teachings; Figure 3 is side view of the hood of Figure 1; Figure 4 is a close-up view of a cuff of the hood of Figure 1; Figure 5 is a close-up view of a through passage in the cuff; and Figure 6 is a close up view of a hose inserted into the passage.

DETAILED DESCRIPTION OF EMBODIMENT(S)

Figures 1 and 2 show a user 2 wearing a respiration system 10 of the present teachings incorporating a hood 12 of the present teachings.

In addition to the hood 12, the respiration system 10 further comprises a powered filter unit 14 and a noise attenuation unit 16 interconnected by a hose 18.

A further hose 20 connects the noise attenuation unit to the hood 12. The powered filter unit 14 and noise attenuation unit 16 are mounted to a belt (not visible) around the user's waist so as to allow free movement of the wearer whilst the respiration system 10 is operating.

The noise attenuation unit minimises the noise generated by the fan, so communication between the user and colleagues and patients with whom they interact is improved.

It will be appreciated that in other embodiments, the powered filter unit 14 and noise attenuation unit 16 may be incorporated within the same housing to further enhance the mobility of the respiration system.

In operation, ambient air is drawn into the respiration system 10 via an inlet (not shown) of the powered filter unit 14, a fan (not shown) of the unit draws air through a suitable filter (not shown) where aerosols and other particles that may contain viruses and other pathogens are captured and then forces the filtered air through the hose 18 into the noise attenuation unit 16. The filtered air is then delivered via the second hose 20 to the hood 12.

In advantageous embodiments the powered filter unit 14 further comprises batteries (not shown). The batteries are preferably rechargeable and may either be of a sufficient capacity to enable air to be delivered for a complete shift or working day (e.g., for 8 hours) and/or may be interchangeable so as to facilitate a rapid battery change if they become depleted. In other embodiments a compressed air supply may be provided on the wearer's body or the respiration system may connect to a central air supply (e.g. of a hospital).

A suitable indication may be provided to the user 2 such as an audible, haptic or visual warning when the battery state is low and the supply of air will therefore shortly cease. In addition, the speed of the fan may be controllable, e.g., to increase the airflow if the user is in a hot or humid environment and therefore requires a greater cooling effect.

Further, it should be noted that by positioning the powered filter unit 14 towards the rear of the user, air is inherently drawn in from a location where there is likely to be a lower concentration of aerosols and particles carrying pathogens than, for example, if it were to be positioned at the front of the user who may be treating a patient who is expressing such aerosols.

With reference to the powered filter unit 14, this is provided with filter media that meets at least a TH2 but preferably a TH3 level of filtration, or an equivalent filtration level. This level of filtration may be achieved by using a suitable high efficiency particulate air (HEPA) filter. It will be appreciated that the level of filtration provided is appropriate to the task being undertaken and contaminants the users requires protection from. Such filters are effective in the current application since although virus molecules are themselves not entirely captured by such filters, their transmission into the human body is typically via being entrained within a liquid aerosol (that may be for example generated when an infected patient coughs) or by being attached to a solid particle that is suspended in the air. Both aerosols and solid particles are effectively captured by such filters.

The hose 20 delivering the air to the hood 12 may have a ribbed outer profile (see for example Figure 6) for reasons discussed in more detail below.

With reference now to Figure 3, the hood 12 is shown in more detail.

The hood 12 comprises a barrier 22 and a cuff 24. In this embodiment, the barrier is formed entirely from a transparent flexible sheet material, for example polyvinyl chloride (PVC). A suitable gauge of material may be in a range of 0.2-0.7mm, e.g. 0.2, 0.3mm or 0.5 mm. Such material has excellent barrier properties against the aforesaid aerosols and particles, whilst being lightweight and offering high clarity.

In this embodiment, the barrier is formed from a vertically extending tubular portion 26 and a disc-shaped top portion 28. The tubular portion 26 and top portion 28 may be stitched, heat or ultrasonically welded together to form an impermeable barrier. Further, it will be appreciated that this construction allows the height of the hood to be easily adapted for different applications simply by altering the height of the tubular portion 26. For example, if a user is required to wear a hard hat under the hood, the height of the tubular portion 26 may be increased to accommodate it. Nevertheless, it will be appreciated that in other embodiments, different shapes may be used, such as domes.

A barrier 22 that is wholly transparent is preferred. However, it will be appreciated that in certain applications it may be desirable that a portion of the barrier 22 may be manufactured from opaque or translucent material, e.g., to provide shading in sunny environments. However, it is anticipated that at least 50% of the surface of the barrier 22 be transparent such that the visibility of the user 2 outwards is maintained, and the barrier also does not overly obstruct the view of the user by people who are interacting with the user.

In this embodiment the barrier is provided with a port 52 through which a straw may be introduced for refreshment whilst the hood is fitted. This may be an opening of e.g. lcm or less in diameter that is covered by a flap 54 on the interior. In normal use, positive air pressure within the hood closes the flap, but if a straw is introduced the flap opens to allow it through. In other embodiments the flap may not be needed (provided the airflow is sufficient to keep the hood inflated whilst it is open), or the port may be omitted entirely.

The cuff 24 is principally a flexible sheet mounted to the lower margin of the barrier 22 around the full perimeter thereof.

The cuff 24 is arranged to fit around a neck 6 of the user 2 and comprises an adjustment mechanism 30 that enables the cuff to be adjusted to provide a snug fit around the neck (e.g., as snug as a person would typically wear a tie). In this embodiment, the adjustment mechanism comprises a strap or webbing 32 that is held within loops 34 arranged around the surface of the cuff 24 to enable the strap to slide relative to the cuff. A free end of the strap 32 is provided with one part 36 of a hook and loop fastener (e.g., hooks) that may be releasably fastened to the other part 38 (e.g., loops) that are secured to the surface of the cuff 24. A similar arrangement (not visible) is provided on the opposite side of the cuff, thereby enabling the strap 32 to be pulled tighter or looser and secured at its free ends by inter-engaging the hook and loop fasteners. It should be appreciated that this arrangement is one of only a number of possible mechanisms. For example, drawstring or elasticated arrangements may also be utilised, as may flexible ratcheted rack and pinion type adjusters.

In this embodiment, the cuff 24 is a permeable material. Specifically, the cuff is manufactured from a sheet of woven fabric that has inherently permeable characteristics. This may for example be a woven cotton, wool or other natural fibre or woven artificial fibres such as polyester or acrylic. In other embodiments a non-woven permeable material may be used.

The permeability of such materials is important, since it allows for the controlled escape of the air being pumped into the hood so as to maintain a positive pressure within the hood 12 that keeps it inflated and prevents the seepage of non-filtered air into the hood.

At the same time the permeable material additionally captures aerosols and particles that may be generated during the breathing of the user 2. This may be particularly important in certain settings such as healthcare where the user 2 may unknowingly be infected with a particular virus or other infectious disease and may be at risk of transmitting that disease to their co-workers or patients that are not otherwise infected.

Further, such materials also tend to be comfortable to be worn against the skin and can wick away perspiration such that the user remains cool, and present a low risk of allergic reactions.

By using such material (in particular woven or nonwoven material) for the cuff 24, it therefore becomes possible to attach the cuff to the barrier 22 by stitching and to construct the adjustment mechanism also via stitching. This reduces the cost and complexity of production of the hood 12. In Figure 4, it can be seen that the stitching 40 extends along the upper margin of the cuff to secure it to the barrier 22. Whilst some air in the hood 12 may escape via the stitching, it will be appreciated that due to the positive pressure within the hood, the passage of air will only ever be from the hood outwards and therefore this does not compromise the effectiveness of the hood.

It can be seen that a further line of stitching 42 extends the full height of the cuff 24 towards the rear of the hood. This stitching 42 sub-divides the cuff into a major portion that receives the user's head and sits around the user's neck as described above and a minor portion 46 that acts as a passage to receive the hose 20 in order to supply air into the hood 12. It will be appreciated that the location of the stitching 42 will be determined by the diameter of the hose 20, with the passage 46 formed by the stitching allowing the hose to be inserted relatively easily, but not being too large that the hose 20 is too loose a fit.

A retainer mechanism 45 is additionally provided such that when the hose 20 is inserted into the passage 46 as depicted in Figure 6, it does not fall out under gravity or under axial loads caused by movement of the wearer. Specifically, safety standards dictate that the connection of the hose to the hood must be able to resist an axial force due to a mass of 15kg.

In this embodiment, it can be seen that the retainer mechanism 45 comprises three flexible cords 48 that encircle the passage 46 when tied (see Figure 6 in which only one cord is shown for clarity). In particular by virtue of the ribbing on the hose 20 the cords 48 can compress the walls of the passage 46 into the valleys of the ribbing to enhance the mechanical retention of the hose to the passageway. Corresponding slits or eyelets 50 are provided in the opposing walls of the major portion 44 of the cuff adjacent the stitching 42, through which the cords 48 are fed in order to facilitate their encircling of the passage 46. Although three cords 48 are shown in this embodiment, it will be appreciated that in other embodiments the number may be adjusted as required to give a suitable level of retention. Further, alternative retainer mechanisms may be used such as one or more cords or tapes stitched into the sides of the passage, hook and loop fasteners, plastic cable ties, elasticated cords, adjustable buckles in conjunction with webbing or ribbons, for

example.

To operate the respiration system 10, the user 2 will initially, when in a non-hazardous environment, connect the hose 20 to the hood 12 using the retainer mechanism 45 as described above. They will mount the powered filter unit 14 and noise attenuation unit 16 around their waist, don the hood 12 over their head 4, turn on the powered filter unit 14 to provide the supply of air, and then use the adjustment mechanism 30 to ensure a snug but comfortable fit around their neck 6.

The user is then ready to enter an infectious or hazardous environment with the respiration system operable to provide suitable protection from infection or other hazardous airborne pathogens or hazardous material. In addition by fully covering their entire face and head, physical transfer of pathogens is also avoided, if for example the user touches their face with their hands. This may not be the case with conventional PPE in which the eyes in particular are exposed.

It will be appreciated that whilst using the respiration system 10 users with glasses or beards are not operationally disadvantaged and protection is not compromised. For example, the user 2 can adjust their glasses or indeed, even remove them entirely by depressing the flexible material of the barrier 22 and grasping their glasses without potentially transferring pathogens onto their surface. Similarly other safety equipment ear defenders, communication systems etc may be worn and adjusted under the hood. Additionally, the user 2 may utilise the drinking port 52 in the barrier 22 to consume liquid refreshments or food without needing to remove the hood.

Removal of the respiration system may be achieved quickly and safely by releasing the adjustment mechanism 30 and lifting the hood 12 over the user's head 4. In contrast with other types of PPE such as masks and head covers this presents a lower risk of mucous membranes coming into contact with contaminated parts of the PPE during the doffing operation, becuase for the present hood, those contaminated parts remain facing outwards during the doffing operation.

Once the hood is removed, the hose 20 can be released from the passage 46 and the hood 12 disposed of or alternatively disinfected prior to re-use, for example, in a dilute bleach solution, or a suitable decontaminant for the particular contaminant that has been encountered.

It will be appreciated that numerous changes may be made within the scope of the present teachings. For example, the cuff 24 may be extended in length to additionally act as an apron, gown or poncho, depending upon the type of permeable material used for the cuff, the stitching may be replaced with heat or ultrasonically bonded seams, or the cuff may be adhesively secured to the barrier.

Whilst the teachings have been described primarily in the context of use of the respiration system in healthcare environments, it should be understood that such a system may be used by other key workers that come into contact with viruses such as Covid-19 and other pathogens in the course of their work, such as police officers, fire fighters, nursing home workers, cleaners, logistics personnel, retail personnel, or indeed users of public transport or workers that may have particular concerns or be particularly vulnerable to infection.

Additionally, the respiration system may be used for other purposes, such as for hay fever sufferers wishing to avoid contact with pollen or other similar allergy sufferers. With suitable filtration the hood and respiration system may also be used to provide protection against hazardous dust and fibres such as asbestos, wood, pharmaceuticals, food etc.

Claims (17)

1. CLAIMS1. A hood for wearing over a head of a user to provide protection against airborne matter such as virus containing aerosols and the like; the hood comprising: a barrier enclosing the head and formed at least partially of transparent flexible sheet material; a structure to permit the connection of a hose thereto from a clean air supply a cuff arranged around the lower edge of the barrier to sit against a neck of the user, optionally wherein the cuff is formed at least partially of a permeable material so as permit egress of air whilst capturing aerosols and/or particles therein.
2. 2. The hood of claim 1 wherein the permeable material is a flexible sheet material.
3. 3. The hood of claim 1 or claim 2 wherein the cuff comprises an adjustment mechanism, e.g. a hook and loop fastener, buckle, elasticated and/or drawstring arrangement.
4. 4. The hood of any preceding claim wherein the cuff comprises the structure for connection of the hose.
5. 5. The hood of claim 4 wherein the structure comprises a discrete through-passage formed in the cuff for the insertion of the hose therein.
6. 6. The hood of claim 4 or claim 5 wherein the structure further comprises retainer mechanism to hold the hose within the through passage.
7. 7. The hood of claim 6 wherein the retainer mechanism comprises a flexible cord, tie, strap, webbing or ribbon arrangement.
8. 8. The hood of any preceding claim wherein the permeable material is a fibrous material.
9. 9. The hood of claim 8 wherein the cuff is formed of a woven or non-woven fibrous material, e.g. woven thread material such as cotton, wool, polyester or the like.
10. 10. The hood of any preceding claim wherein more than 50%, optionally more than 70% or optionally more than 90% of a surface of the barrier is formed of transparent flexible sheet material e.g. polyvinyl chloride.
11. 11. The hood of claim 10 wherein substantially all of the barrier is formed of transparent flexible sheet material.
12. 12. The hood of any preceding claim further comprising a port in the barrier for the insertion of a straw.
13. 13. A respiration system comprising a hood according to any preceding claim and an air delivery unit
14. 14. The respiration system of claim 13 wherein the air delivery unit comprises a 1H2 or TH3 level, or equivalent standard, filter.
15. 15. The respiration system of claim 13 or claim 14, further comprising a hose connecting the filter to the hood, optionally the hose being ribbed.
16. 16. The respiration system of any of claims 13 to 15 wherein the air delivery unit further comprises a fan and energy storage device arranged to power the fan.
17. 17. The respiration system of any of claims 13 to 16 further comprising a sound attenuation device upstream of the hood.