CN112274795A

CN112274795A - Face mask

Info

Publication number: CN112274795A
Application number: CN202010704298.XA
Authority: CN
Inventors: R·A·H·雷克斯; 秦峰
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2019-07-22
Filing date: 2020-07-21
Publication date: 2021-01-29
Anticipated expiration: 2040-07-21
Also published as: CN213374824U; WO2021013664A1; CN112274795B

Abstract

Embodiments of the present disclosure relate to masks. The mask includes a filter member and a fan assembly. The fan assembly has two modules, one module connected to the filter member and the other module carrying the reusable components of the fan module. The two modules are connected together by a spring-biased coupling.

Description

Face mask

Technical Field

The present application relates to masks for providing filtration of contaminants.

Background

Air pollution is a concern worldwide. The World Health Organization (WHO) estimates that 400 million people die of air pollution each year. Part of this problem is the outdoor air quality in cities. Nearly 300 cities affected by haze do not meet the national air quality standards.

The official outdoor air quality standard defines particulate matter concentration as mass per unit volume (e.g., μ g/m 3). Of particular interest is contamination of particles smaller than 2.5 μm in diameter (referred to as "PM 2.5") because particles smaller than 2.5 μm in diameter are able to penetrate into the gas exchange areas of the lungs (alveoli) and very small particles (<100nm) can affect other organs through the lungs.

Since the problem does not improve significantly in the short term, a common method of solving the problem is to wear a hood that can provide cleaner air through filtration. In recent years, the market for covers in china and other areas has been expanding dramatically.

Such a cover may be made of a material that acts as a contaminant particle filter, or may have a filter for only a portion of the cover surface and may be replaced when the filter is clogged.

However, during use, the temperature and relative humidity inside the mask increase and add to the pressure differential inside the mask relative to the outside, which makes breathing uncomfortable. This can be partially alleviated by providing an outlet valve or one-way valve which allows exhaled air to escape the mask with little resistance, but requires inhaled air to pass through the filter. To improve comfort and effectiveness, a fan may be added to the mask that draws air through the filter and/or assists in exhaling.

A possible benefit to the wearer of the use of a fan-powered mask is that slight deformation of the lungs caused by inhalation overcoming the resistance of the filter in a conventional unpowered mask is eliminated. In addition, in conventional unpowered enclosures, the inhalation also causes a slight pressure drop within the enclosure, which results in leakage of contaminants into the enclosure, which can prove dangerous if the contaminants are toxic substances.

Accordingly, the fan assisted shroud can improve breathing comfort by reducing temperature, humidity and breathing resistance.

In one arrangement, an inlet (i.e. suction) fan may be used to provide continuous air introduction. In this way, slight deformations of the lungs caused by inhalation overcoming the resistance of the filter in a conventional unpowered enclosure are eliminated. A steady flow of air may then be provided to the face and, for example, a slight positive pressure may be provided to ensure that any leaks are outward rather than inward. However, this causes additional resistance to breathing during exhalation.

In another arrangement, an exhaust (i.e. exhalation) fan may be used to provide continuous air release. This instead provides respiratory assistance when exhaling. The exhalation fan may be used in conjunction with an in-line one-way valve so that flow cannot pass through the fan into the hood.

The fan again creates a continuous flow of air through the shroud. The flow induced by the fan draws air through the filter into the hood volume. This improves the comfort of the wearer.

Another alternative is to provide both an intake fan and an exhaust fan and synchronize the control timing of the fans to the user's breathing cycle. The breathing cycle may be measured based on a pressure (or differential pressure) measurement. This improves temperature and humidity control and reduces resistance to breathing during inhalation and exhalation.

Accordingly, several types of masks for preventing daily exposure to airborne contaminants are provided, including passive masks, passive masks having exhalation valves, and masks having at least one active fan.

The invention relates in particular to an active enclosure with a fan. One problem is that the hood filter needs to be cleaned or replaced regularly. The fan is typically formed in a manner that creates a seal between the fan and the hood filter. To separate the fan from the hood filter, the seal needs to be released because the fan (and in particular the fan-related electrical and electronic components) are not suitable for cleaning and do not need to be replaced regularly as a filter.

There is a need for a connection system that enables the shroud filter to be separated from the fan in a low cost, yet robust manner such that release and re-connection can be performed multiple times. This connection is required to provide good alignment between the fan and the shroud filter, or the components will be under tension, resulting in filter distortion, assembly difficulties and durability problems.

EP0352113 discloses a forced draft filter device for protecting an enclosed space, such as a breathing space of a gas hood or the like. The filter is formed in the canister and is snap-fit attached to the blower housing.

Disclosure of Invention

The invention is defined by the claims.

According to an example of an aspect of the present invention, there is provided a mask comprising:

a filter member for fitting over the face of a wearer of the mask to cover the mouth and nose of the wearer;

a fan assembly, wherein the fan assembly comprises a connector module secured to a portion of the outer surface of the filter member and a fan module, wherein the connector module and the fan module together comprise a detachable coupling to enable the filter member to be separated from the fan module,

wherein one of the connector module and the fan module comprises a receiving channel or set of receiving channel portions and the other of the other connector module and the fan module comprises spring biased engagement features adapted to engage with the receiving channel or set of receiving channel portions to provide attachment of the connector module to the fan module for said detachable coupling.

The shroud has a connection between two modules of the fan assembly and thus between one module of the fan assembly and the filter member, which is achieved by a spring biasing system. Durability can be improved by using a spring-biased connection instead of an interference fit (e.g., plastic components) to periodically replace the filter. This design also eases assembly since the receiving channel design does not need to be aligned precisely for use.

The receiving channel may comprise an annular channel (such as a circular channel), or the receiving channel portion may comprise an annular channel portion (such as a portion sharing a circular channel).

This allows the two components to be coupled over one or more continuous ranges of relative angular orientation.

The engagement of the spring-biased engagement features with the receiving channel (or set of receiving channel portions) preferably provides attachment of the connector module to the fan module by a push fit. Thus, the spring biased system can be pressed ("snapped") together.

When the two modules are pressed together, the spring-biased engagement feature is pushed back, for example, and then returns to its original position (or at least to a less deformed position) when the spring-biased engagement feature engages with the receiving channel (or receiving channel portion). The two modules are then held together and have some rotational freedom if they are circular annular channels.

The spring-biased engagement feature is durable, for example, by ensuring that the spring-biased engagement feature deforms only within its elastic range. A large amount of deformation can be allowed and this results in less important alignment between the two modules, making assembly of the components easier.

In the example using a circular annular channel, the coupling, once connected, can rotate freely at least within a limited angular range, since only rotational friction prevents rotation.

The spring-biased engagement feature comprises, for example, a set of spring-biased lugs. Therefore, there is a small frictional force that prevents rotation of the coupling portion. The lug is made of, for example, a resilient metal.

The spring-biased engagement feature may instead comprise a spring ring. The spring ring may expand when radially outside the receiving channel and may contract when engaged with the receiving channel.

Another possible example is a set of spring biased ball bearings that extend into the channel or channel portion.

The fan module includes, for example, a fan and a fan motor. By separating the fan module and the connector module, the fan and the motor are separated from the filter member, so that the filter member (to which the connector module is attached) can be replaced or cleaned.

In one example, the fan module may further include a one-way valve. In this case, the connector module may simply comprise a connector which forms a seal with the filter member.

In another example, the connector module may include a one-way valve. The one-way valve may be a low cost component and it may also be washable, so that the one-way valve may become a component of the filter member.

In both cases, the fan assembly (combined fan module and connector module) in turn defines a fan and one-way valve assembly.

The fan module has, for example, spring-biased engagement features and the connector module has a receiving channel or set of receiving channel portions.

The fan assembly for example comprises an exhaust (or exhalation) fan for exhausting air from the volume defined by the inner filter member. This is a possible option for the fan to provide a continuous air release. The exhaust fan provides breathing assistance when exhaling and ensures a continuous air supply to the face. The exhaust fan is for example combined with a one-way valve (which may be part of the connector module or the fan module).

The mask preferably further comprises a control unit, wherein the control unit and the fan assembly are located on opposite lateral sides of the mask.

This provides a balance of the weight of the various components on opposite sides of the shroud. The controller sends a control signal to the fan, for example. It may include a respiration sensor, a temperature sensor, a pressure sensor, etc. The control unit for example comprises a battery unit and optionally also control circuitry for the fan assembly (some or all of the control circuitry may be at the fan module).

An electrical connector bridge located outside the filter member is then preferably provided between the control unit and the fan module. Thus, when the connector module and the fan module are decoupled to allow replacement of the filter member, the electrical connector bridge remains in place.

The filter member may define an outer surface of the housing. The decoupling of the connector module and the fan module substantially disconnects the reusable (and non-cleanable) portion of the shroud from the filter member. However, in another design, the enclosure further comprises a housing, wherein the filter member is an internal filter member for mounting inside the housing.

This provides a protective enclosure. The internal filter member is, for example, a push fit to connect to the housing, for example with an ejector.

In one design, the control unit is attached to the interior of the housing. Thus, when the first and second modules are decoupled, the control unit and the fan module of the fan assembly (and the electrical connector bridge between the control unit and the fan module of the fan assembly) remain supported by the housing.

In another design, the control unit is removably attached to the inner filter member. This may be a positioning function only, rather than a fixed connection.

A magnetic coupling may be provided to hold the control unit in place.

The housing, for example, includes an opening and the fan module is secured to the housing in alignment with (and extending into or through) the opening.

A fan module for use in a mask as defined above comprising:

a receiving channel or set of receiving channel portions adapted to engage with spring-biased engagement features of a connector module (e.g., by push-fitting); or

A spring biased engagement feature adapted to engage with a receiving channel or set of receiving channel portions of a connector module (e.g., by push fitting).

The present invention also provides a filter for use in a mask as defined above, comprising:

a filter member for fitting over the face of a wearer of the mask to cover the mouth and nose of the wearer; and

a connector module attached to a portion of an outer surface of the filter member, wherein the connector module comprises:

a receiving channel or set of receiving channel portions adapted to engage with spring-biased engagement features of the fan module (e.g. by a push fit); or

A spring biased engagement feature adapted to engage with a receiving channel or set of receiving channel portions of the fan module (e.g., by a push fit).

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

Drawings

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings in which:

FIG. 1 shows an example of a design of a shroud to which the present invention may be applied;

FIG. 2 shows the design of FIG. 1 in an assembled state from the front side;

FIG. 3 shows the design of FIG. 1 in an assembled state from the opposite front side;

FIG. 4 is for showing the manner in which components interact with a wearer and shows an alternative design;

FIG. 5 shows an exploded view of a control module of the design of FIGS. 1-3;

FIG. 6 shows a coupling design used in either cover design;

FIG. 7 illustrates one possible design of a spring-biased engagement feature;

FIG. 8 illustrates another possible design of a spring-biased engagement feature;

FIG. 9 illustrates another possible design of a spring-biased engagement feature; and

fig. 10 shows another possible design of a spring-biased engagement feature.

Detailed Description

The present invention will be described with reference to the accompanying drawings.

It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems, and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. It should be understood that the figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

The present invention provides a mask that includes a filter member and a fan assembly. The fan assembly has two modules, one module connected to the filter member and the other module carrying the reusable components of the fan module. The two modules are connected together by a spring biased coupling, preferably by a push fit coupling.

Figure 1 shows an example of a design of a cover to which the invention can be applied. The enclosure 10 is shown in an exploded view and includes an outer housing 12 and an inner filter member 14. The housing is rigid or semi-rigid, with ear straps 13, whereas the filter member 14 is for example made of fabric and is therefore easily deformable, so that the outer edge can match the shape of the wearer's face. The inner filter member 14 is intended to fit over the face of the wearer of the mask to cover the mouth and nose of the wearer. This therefore provides filtration of the air breathed by the wearer.

The housing is porous so that air can flow through the housing.

The inner filter member 14 is sealed around the connector module 16. Connector module 16 is for connecting to fan module 20. In this particular example, the connector module 16 includes a passive one-way valve. The connector module and fan module may be considered together to comprise a fan assembly, and the two modules may be manually connected together and disconnected. Thus, the connector module and the fan module together comprise a detachable coupling to enable the inner filter member to be separated from the fan module. The wearer breathes through the internal filter member, particularly through the internal filter member in a region outside the connector module region. Thus, the area outside the connector module serves as a filtering system for the air breathed by the wearer. As shown, the connector module is connected to a portion of the outer surface of the filter member. In particular, in this example, the connector module is connected to a portion at a lateral side of the filter member.

The control module 18 is coupled to the exterior of the filter member 14. The control module includes a fan module 20 of a fan assembly and a control unit 22. The control unit 22 includes, for example, a battery and other control circuits. Which may include a sensor. It is noted that the control circuit may be located opposite the side of the fan module. Thus, various additional circuit elements and batteries may be divided in different ways between the fan module and the control unit.

The connector module 16 is permanently secured to the filter member 14 so that the connector module 16 is discarded with the filter member 14 when the filter is replaced. The fan module 20 of the fan assembly is reusable and includes (at least) a fan drive circuit and a fan impeller.

Housing 12 has an opening 24 in which opening 24 fan module 20 of the fan assembly is received.

The inner surface of the housing may also have a receiving seating area for the control unit 22, or on the outer surface of the filter member may have a receiving seating area 26 for positioning the control unit 22. The control unit may be connected to the filter member or housing by magnetic coupling and mechanical alignment features or by magnetic coupling instead of mechanical alignment features.

The electrical connector bridge 28 provides an electrical connection between the control unit 22 and the fan modules 20 of the fan assembly for the transmission of power and control signals.

The fan module 20 and control unit 22 of the fan assembly are located on opposite lateral sides of the mask, i.e. one on each side of the wearer's nose. This provides a balanced weight distribution. By having two modules, the weight of each component is reduced, thereby reducing the load at either location.

In this example, the fan module is an exhaust fan. In the simplest design, the fan module runs continuously to provide a continuous supply of air to the face (using air drawn through the mask filter). This provides temperature and humidity control. However, the fan module may be operated in synchronism with the breathing of the wearer (with appropriate breathing sensing) and may be controlled bi-directionally.

Since the invention is particularly concerned with the physical assembly of the fan module with the filter member, regardless of how the fan module is controlled in use, all options for fan control can be applied.

Fig. 2 shows the design of fig. 1 in an assembled state from the front side, and fig. 3 shows the design of fig. 1 in an assembled state from the opposite front side.

Fig. 4 is for showing the way the components interact with the wearer and shows an alternative design of the single module. The invention is equally applicable to single module designs. The face 30 of the wearer is shown in cross-section from above.

The inner filter member 14 is connected to the outer shell 12 by fasteners 32. These fasteners are, for example, push-fit ejectors (poppers). The outer periphery of the inner filter member also carries an inwardly projecting seal 34 to form a substantially closed volume between the inner filter member and the face 30.

The single module of this example is centrally located (again weight balanced). As shown in the example of fig. 1, the module includes a connector module 16 and a fan module 20. The fan module 20, in turn, contains the reusable components of the fan assembly and control module.

On inhalation, air is drawn through the filter member 14 as indicated by arrows 36. The exhaust fan may be running during this time to provide flow 38, or the exhaust fan may be turned off to save power. Upon exhalation, the exhaust fan is operating to produce flow 38, and there may also be outward flow (as indicated by arrows 40) through the filter member. Flow 36 may also continue (depending on the manner in which the fan is operating), but at that time the flow is not being drawn in, but instead is being circulated out by the fan. Breathing comfort is improved, in particular because the fan removes exhaled air from the mask cavity, preventing re-breathing (recirculation) of previously exhaled and therefore stale air.

The single module may, for example, include a fan, a one-way check valve, a battery, and a printed circuit board carrying control circuitry. The fan is on top of the one-way valve.

In the example of fig. 4, connector module 16 and fan module 20 are again detachable so that the internal filter components can be replaced (or cleaned) when the module is reused.

Returning to the design of fig. 1-3, fig. 5 shows an exploded view of the control module 18.

Fan module 20 of the fan assembly includes an outer housing 40, a power button 42 extending through opening 44, a fan control circuit board 46, a main housing 48 of fan module 20 that houses a fan motor 49, a fan impeller 50, and a pressure plate 52. The pressure plate improves the performance of the fan and protects the impeller from any potential misuse by the user, such as touching the impeller in any way.

The fan module is connected in parallel with the filter member, rather than in series with the filter member.

The control unit 22 includes an outer housing 60, a battery 62, a control unit circuit board 64, and an inner housing 66.

The control unit is not intended to be detached or detached by the user. Instead, as mentioned above, the control unit is retained as a closed unit on the inner surface of the housing or in a receiving opening on the outer surface of the filter member.

The invention particularly relates to the manner in which two fan assembly modules are coupled together.

Fig. 6 shows this coupling design.

In this example, the connector module 16 includes a receiving channel 70, in this example an annular channel, particularly a circular annular channel, and the fan module includes a spring-biased engagement feature 72. The circular receiving channel makes it possible to connect in different relative rotational positions. However, the receiving channel may have other shapes, such as a polygon or the like. Again, this may allow connections to be made in a discrete number of different orientations.

The left diagram of fig. 6 shows the connector module and the fan module separated, and the right diagram shows the connector module and the fan module coupled together. When coupled together, the features 72 engage with the annular channel 70, thereby providing attachment of the connector module to the fan module. This is preferably achieved by a push fit, however push and twist connections are also possible, with the resulting twist engaging the spring biased engagement feature with the channel or portion of the channel. In all cases, retention is achieved by engagement against the spring bias, rather than by a tight fit such as threads or the like.

The connector module 16 is connected to the filter member 14, for example by ultrasonic welding, to form a seal around the connector module 16. In this example, the connector module 16 defines a one-way valve 94, such as a rubber flap valve. Fan module 20 is connected to housing 12, for example by being clamped to housing 12 during assembly. The connection is not intended to be released by the user.

The annular channel 70 results in a ring 76 having a larger diameter above the channel. When connector module 16 is pushed into fan module 20 (the arrows are intended only to indicate relative movement), features 72 are deflected radially outward by ring 76 and then folded back into channel 70.

Because the channel is annular, relative rotation between the two modules is possible. Thus, the connection can be made without the need for accurate angular alignment. This also means that little force is applied to the filter element, for example no significant torsional forces, which could damage the filter material.

In the example shown, the features 72 comprise lugs.

As shown in fig. 7, the lug includes a support arm 80 and a head 82. The head is designed to fit into the access passage and the support arms provide a radially inward spring bias. The main housing 48 is designed to provide space for the lugs to deflect outwardly as they ride over the ring 76 during coupling.

There may be only two diametrically opposed lugs or, more preferably, groups of three, or there may be more than three. The annular channel need not be continuous. There is a correct orientation for the fan module 20, in particular so that the electrical connector bridge 28 is in the correct position. Thus, only a few degrees of angular freedom are required for adjustment, rather than full angular control. Thus, the annular channel may comprise a set of annular channel portions (one for each lug), but they need not form a continuous channel. Thus, more generally, the receiving channel may comprise a group of receiving channel portions, and these portions may be annular portions (this is called "annular channel portions").

The channels and lugs can of course be interchanged, the channels being on the fan module and the lugs on the connector module.

The features 72 are preferably metal to provide increased flexibility and durability compared to plastic features.

The use of a spring biased connection instead of an interference fit allows the filter to be periodically replaced (or separately cleaned).

Features 72 have alternatives.

Fig. 8 shows an alternative to forming a loop, which may be considered a spring loop. This shows the loop from above. It has fixing points 90 (at a diameter greater than the channel) and an edge 92 extending between these fixing points. The ring expands when positioned around ring 76 because the sides flex outward. When the sides straighten under the force of the spring, the ring will contract when engaging the annular channel.

There may be three, four or more sides.

There are other possible connector designs.

Fig. 9 shows the loop of the spring-biased engagement feature in the form of straight upstanding lugs 94(straight upstanding tabs). When introduced into the channel, the straight upstanding lugs 94 deflect outwardly and spring back radially inwardly into the channel. These straight upstanding lugs 94 may be considered to be the elongated form of the lugs of fig. 7 to define a nearly continuous loop.

Fig. 10 shows a spring-loaded recessed ball bearing 100, the recessed ball bearing 100 serving as a spring-biased engagement feature. When the annular channel flange passes, the recessed ball bearing 100 will be pressed into the socket of the recessed ball bearing 100 and then re-extended to engage the channel. There may additionally be a locking sleeve which locks the ball bearing in a radially inner position, thus requiring movement of the sleeve to make and break the connection. This provides additional security.

The designs of fig. 8-10 may be attached to the channel design as shown in fig. 6, respectively.

Thus, various spring seat rotary couplings are possible, preferably achieving a push fit connection.

The main example above has an outer shell and an inner cover. However, the same attachment method may be used for a mask having only a filter layer. The fan assembly is then attached to the filter layer in the same manner, i.e. the shroud of fig. 1 does not require an outer shroud. The control unit may be connected to the filter in the same manner as the fan module, with the same (e.g. push-fit) spring-biased arrangement. Rather, the control unit may be connected in different ways, such as with an interference fit plastic part, a plastic and rubber part with an interference fit, or velcro, a push button device, a magnet, or any other suitable design. This is not a critical coupling as the coupling does not involve sealing. The filter will then have a strap or other connection for fitting the mask to the wearer.

In designs with a housing, the control unit need not be firmly attached to the filter or housing, but rather simply held in place, such as by simply docking into the receiving opening.

When a housing is used, the inner filter member may be connected to the housing in any suitable manner. Preferably, a push fit connection is used, as this allows the filter member to be easily connected and disconnected from the housing.

The connection system as described above may be applied to a shroud with a fan and control module or with separate control and fan modules as shown in detail above.

The connection between the connector module and the fan module may take various forms. The fan modules may have smaller male coupling components, i.e., protruding annular channels, or the connector modules may have smaller male coupling components.

Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. If the term "adapted" is used in the claims or the description, it is to be noted that the term "adapted" is intended to be equivalent to the term "configured to". Any reference signs in the claims shall not be construed as limiting the scope.

Claims

1. A mask, comprising:

a filter member (14) for fitting over the face of a wearer of the mask to cover the mouth and nose of the wearer;

a fan assembly, wherein the fan assembly comprises a connector module (16) and a fan module (20), the connector module (16) being secured to a portion of the outer surface of the filter member, wherein the connector module and fan module together comprise a detachable coupling to enable the filter member (14) to be separated from the fan module (20),

wherein one of the connector module (16) and fan module (20) comprises a receiving channel (70) or group of receiving channel portions and the other of the connector module and fan module comprises a spring-biased engagement feature (72), the spring-biased engagement feature (72) being adapted to engage with the receiving channel (70) or group of receiving channel portions to provide attachment of the connector module (16) to the fan module (20) to enable the detachable coupling.

2. The mask of claim 1, wherein the receiving channel comprises an annular channel or the receiving channel portion comprises an annular channel portion.

3. The mask of claim 1 or 2, wherein attachment of the connector module (16) to the fan module (20) is provided by engagement of the push-fit spring-biased engagement feature (72) with the receiving channel (70) or group of receiving channel portions.

4. The mask according to any one of claims 1 to 3, wherein the spring-biased engagement feature (72) includes:

a set of spring-biased lugs (72; 94); or

A spring ring (92); or

A set of ball bearings (100).

5. The mask according to any one of claims 1 to 4, wherein the fan module comprises a fan and a fan motor, and wherein the mask further comprises a one-way valve, wherein the one-way valve is a component of the connector module or a component of the fan module.

6. The mask of any one of claims 1 to 5, wherein the fan module (20) has the spring-biased engagement features and the connector module (16) has the receiving channel or group of receiving channel portions.

7. The mask according to any one of claims 1 to 6, wherein the fan assembly includes an exhaust fan for exhausting air from a volume defined by the interior filter member.

8. The mask according to any one of claims 1 to 7, further comprising a control unit (22), wherein the control unit (22) and the fan assembly (16, 20) are located on opposite lateral sides of the mask.

9. The mask of claim 8, further comprising an electrical connector bridge (28), the electrical connector bridge (28) being located between the control unit (22) and the fan module (20), the electrical connector bridge being located external to the filter member.

10. The mask according to claim 8 or 9, wherein the control unit comprises a battery unit and optionally further comprises control circuitry for the fan assembly.

11. The mask of any one of claims 1 to 10 further comprising a shell, wherein the filter member is an internal filter member for mounting inside the shell.

12. The mask according to claim 11, wherein the control unit is:

attached to the interior of the housing; or

Removably attached to the inner filter member.

13. The mask of claim 11 or 12, wherein the shell includes an opening and the fan module is secured to the shell in alignment with the opening.

14. A filter adapted for use in a mask according to any one of claims 1 to 13, comprising:

a receiving channel or set of receiving channel portions adapted to engage with spring-biased engagement features of the fan module; or

A spring biased engagement feature adapted to engage with a receiving channel or set of receiving channel portions of the fan module.