Air filter device for breathing device

Abstract

An air filter device (1) for a breathing device, such as a mechanically ventilated breathing circuit including CPAP and BiPAP devices or a tracheal humidifier, comprises a container (2) in which a filter member (13) is placed. The latter is not equipped with a containment frame and is single-component so as to be easily disposable.

Description

[0001]AIR FILTER DEVICE FOR BREATHING DEVICE The present invention relates to a disposable humidifying element or filter (in the following, "air filter device") according to the preamble of the main claim. Such disposable filter device is suitable for use (for a few hours and up to a few days) in patient ventilation systems such as a mechanically ventilated breathing circuit, a sleep apnea device (such as a CPAP or BiPAP device) or a tracheal humidifier or in general in breathing devices, also such as face masks. A filter device of the type mentioned above usually comprises a casing adapted to contain a filter member which normally includes a perimeter structure or frame containing the filter element or member. The latter can be defined by a paper filter, a sponge or similar and the frame is necessary to provide protection and prevent the filter from changing its shape being so ineffective. Known air filters devices operate in an optimal manner, but they present problems in the disposal stage, above all when they are used in the domestic environment (i.e. for "home-care") and not in hospitals. Especially in this case, the disposal of the filter member can cause problems precisely because it includes parts (in plastic or other material) which should be disposed of separately. Because the filter member parts cannot be disposed of separately, the whole filter member is disposed of as "undifferentiated" to general waste or landfill keeping it in the form of use and without separating its components according to the material with which they were made. This can cause problems for the user, the environment and for the waste disposal companies. US2017119991 relates to a self-contained re- humidification mask having locating means to enable the mask to be supported in an operative position on a user (4). The mask has a wall shaped as a moulded dome and configured to cover the face of a user from the nose to the chin. An endless peripheral edge is shaped and configured to generally anatomically follow the contours of a face of a user to define, with the face of the user, an air pocket. The mask has a single inlet-outlet aperture located generally opposite to a position occupied in use by a mouth of a user, and at least one re-humidification assembly located in the inlet-outlet aperture such that it substantially fills the aperture. The re-humidification assembly includes a coil of corrugated hygroscopic paper having an axis of the coil extending in the direction of fluid flow through the inlet- outlet aperture. The re-humidification mask preferably has a wall formed from a non-woven synthetic fibre sheet; the mask has a tubular holder composed of an inner and outer sleeves which may frictionally engage each other to remain in their operative position wherein they contain the corrugate coil. The sleeves may clip into a cooperating position or may be adhesively secured together and have formations in the form of inwardly directed flanges at opposite ends of the tubular holder for holding the coil of corrugated hydroscopic paper captive within the tubular holder. This prior document neither describes nor suggests the possibility to separate the coil from the tubular holder. Therefore, the prior document does not describe that the coil of corrugated paper be replaced and disposed of by an end user while maintaining the tubular holder for a subsequent use. With the known solution, all the mask has to be disposed after the use or, at most, the whole re-humidification assembly (comprising the tubular body and the coil) must be disposed after the use. EP856328 relates to a medical breathing filter having a flexible tubular outer housing comprising one port connected to the patient and another port connected to a connector at the patient end of a ventilation tubing. A filter assembly comprises a flexible tubular filter mounted coaxially in a housing. The filter has one end sealed to the housing between its two ports. The opposite end of the filter is closed so that gas flowing through the housing flows through the thickness of the filter. Since the filter is sealed to the housing (such as by means of hot-melt adhesive), it cannot be separated by the housing. Therefore, after the use, the complete breathing filter has to be disposed. The possibility to separate the flexible tubular filter from the housing is neither disclosed not suggested. US2006042210 relates to a contaminant-removal filter for removing basic contaminants from a gas stream, such as air. The filter has a porous or fibrous body that includes a plurality of passages extending from a first inlet face to a second outlet face, the passages providing flow paths. The body has an acidic material, such as citric acid, and at least one of a preservative and a stabilizer impregnated throughout the substrate. The filter is free of any humectants. This prior art does not teach that the filter may be inserted into an housing to define a filter device. The object of the present invention is to provide an improved, disposable air filter device, the filter member of which can be disposed of simply and safely. In particular, the object of the invention is to offer an air filter device of the aforementioned type, in particular used but not only used in the domestic environment, the filter member of which can be separated from its plastic housing and disposed of after use. Another object of the present invention is to reduce the material waste and eliminate or reduce the single use of plastic part(s) of the air filter device. These and other objectives are achieved by an air filter device according to the appended claims. For a better understanding of the present invention, the following drawings are attached, by way of a purely non- limiting example, in which: Figure 1 shows an exploded perspective view of an air filter device according to the invention; Figure 2 shows a perspective view of a filter member of the air filter device in Figure 1 during a stage of its construction; Figure 3 shows a perspective view of the filter member in Figure 2 ready for use; Figure 4 shows an enlarged view of a part indicated by A in Figure 2; Figure 5 shows a perspective view of a variant of the filter member of the air filter device in Figure 1; Figure 6 shows a perspective view of the filter member in Figure 5 during a stage of its construction; and Figure 7 shows an exploded perspective view of a container of a plurality of filter elements for the air filter device in Figure 1. With reference to the cited figures, an air filter device according to the invention is indicated generically with 1; the example shown relates to a filter device 1 for a tracheal humidifier. However, the invention in its essential features can also be used with appropriate modifications for other uses in different ventilation or breathing systems in general (such as face masks) of a patient or user. The air filter device 1 comprises a casing 2 having a cup-shaped part 3 presenting a cavity 4 delimited by an opening 5 and by a base 6, in known way, the base is in communication with a pipe 7, and also delimited by a wall 8. Centrally, from the base 6 a pin 10 rises, which is at least partially hollow and open at the top at 11, adapted to be inserted into a through hole 12 of a disposable filter member 13 so as to guide its insertion and positioning in the cavity 4. The filter member in the figures has a toroidal cylindrical body 14 due to the opening or the through hole 12. This hole 12 is made along the longitudinal axis W of the body 14 and is suitable to contain said pin 10 of the casing 2 which protrudes from the hole 12. Through a "living hinge" or flexible flap 20, a closure element 21 is connected to one end of the cup-shaped part 3 close to the opening 5. This element comprises a substantially cup-shaped body 23 having an edge 24 integral with the flexible flap 20 and from which a tube 25 protrudes. This tube, which function is per se known, opens in an inner end 26 of the body 23 which is open from a first side 23A adapted to overlap the opening 5 of the cup-shaped part 3; a second side 23B of the cavity 26 of the body 23 is provided with spokes arms (spokes) 28 connected to an axial tubular body 29. This tubular body 29 (open at its opposite ends) is adapted to be placed at the opening 11 of the pin 10 of the cup-shaped part and above it. Preferably the pin 10 tapers towards the upper opening 11 so that it can be inserted into the axial tubular body 29. A cap 30 protrudes externally from the edge 24 of the body 23 of the closing element 21 and is connected to this edge 24 through a flexible arm 32. This allows the closure of the tubular body 29 and therefore of the pin 10 and at the same time ensures that the cylindrical body 14 of the filter member 13 is retained within the cavity 4 of the cup- shaped body. The casing 2 can be reused after washing, while the filter member 13 is autonomously disposable to be easily replaced after use (normally after a few hours up to a few days of use). This filter member 13 is preferably and advantageously made of a single material such as paper or "paper-like" material or the known material which has the same capacity as the paper to retain humidity. As mentioned, the filter member is preferably made of paper, advantageously corrugated paper. This filter member, in particular, comprises at least one corrugated paper tape 33 which includes chevrons with an opening angle α between 100° and 140°: by varying the angle of the chevrons, the mechanical resistance can be finely adjusted and humidity can be retained by the filter member 13 so as to adapt it to the application. The corrugated paper tape 33 is advantageously and preferably associated, for example glued, to a second paper tape 35. This latter can be of the corrugated type (like the tape 33, see Figures 2-4) or be smooth (as shown in Figures 5 and 6). In the case of the second corrugated tape 35, its chevrons advantageously have a conformation opposite to that of the first paper tape 33, so as to avoid the two ribbons collapsing onto each other and the impossibility of having a correct air flow and humidity between them or in any case a decrease in this flow, with a consequent worsening of the filtering capacity of the filter member 13. As previously stated, the chevrons increase the mechanical rigidity of the filter member 13 and the humidity output, also depending on their inclination. By adjusting the opening angle of the chevrons, these characteristics can be adjusted according to use. The filter member 13 is not equipped with a containment frame, it is self-standing and is an independent member separate from the casing 2. The filter member 13 is obtained by fixing the various layers of the tape 33 or of the tapes 33 and 35 on themselves.This fixing takes place by placing small medical grade glue dots 38 (or "micro-glue dots") on the face 37 of each tape that wraps around the already rolled tape, i.e. the "inner face" of the tape. The glue is cyanoacrylate, medical grade; however other similar adhesives could be used. This glue is biodegradable and can be applied along the entire tape, but also only on one of its ends 40 to close the winding. The filter member 13 thus created is an independent body with respect to the casing 2 of the filter 1 and is made of a single material (in the example, paper) so that it can be easily disposed of. As an alternative, the filter member 13 may be made of different materials: for example, when the filter member comprises two tapes 33 and 35, this tapes can be of different materials for example paper and composite / polymer material. Once used, the casing 2 is opened and the (exhausted and separated) filter member 13 can be easily extracted from the cavity 4 and replaced with a new filter member. It should be noted that, for example, a plurality of filter members 13 can be introduced into a container 51 and each filter member can be extracted individually when necessary, the other filter members remaining in the container and being protected by a closure member 52. In Figure 7 the container 51 has the shape of a tube. However, the container 51 may have any shape and size in order to contain a plurality of filter member 13, for example such as a parallelepiped box or others. Hence, the shape is not a limiting feature of the container 51. A preferred embodiment of the invention has been described. Still others are however possible in the light of the preceding description in order to obtain an air filter device for a breathing device with the characteristics according to the appended claims.

Claims

CLAIMS 1. An air filter device for a breathing device, said air filter device (1) comprising a casing (2), which can be opened, containing a disposable filter member (13) which can be replaced after a first use, characterized in that said filter member (13) is self-standing, is not equipped with a containment frame and is independent from the casing (2).

2. The air filter device according to claim 1, characterized in that the filter member (13) is made of a single material.

3. The air filter device according to claim 2, characterized in that said filter member (13) comprises a body (14) made of paper or similar material, said body being defined by at least one paper tape (33) wrapped around itself and glued, on its inner face (37), at least at one end part (40), said glue keeping the conformation of the aforementioned body (14) stable.

4. The air filter device according to claim 3, characterized in that the paper tape (33) cooperates with glue dots (38) distributed along at least the inner face (37) of its end part (40).

5. The air filter device according to claim 4, characterized in that the glue is accurately arranged on the inner face (37) of the paper tape (33) even at points spaced from its end port.

6. The air filter device according to claim 1, characterized in that said filter member has a body (14) defined by two paper tapes (33, 35) coupled together and wound around themselves.

7. The air filter device according to claim 6, characterized in that said paper tapes (33, 35) are glued together.

8. The air filter device according to claim 6,characterized in that it comprises glue dots (38) placed on the inner face (37) of each tape (33, 35) of the pair of tapes, said glue tapes keeping the conformation of the above body (14) stable.

9. The air filter device according to claim 6, characterized in that at least one (39) of the paper tapes of the pair of paper tapes coupled together is of the corrugated type, including chevrons having an opening angle between 100° and 140°.

10. The air filter device according to claim 9, characterized in that both tapes (33, 39) of the pair of paper tapes which define the body (14) of the filter member (13) are of the corrugated type, the chevrons of a first tape (33) having a conformation which is opposite to the chevrons of the second band (39).

11. The air filter device according to claim 6, characterized in that the tapes of the filter member (13) are made of different materials.

12. The air filter device according to claim 1, characterized in that the casing (2) comprises a cup-shaped part (3) presenting a cavity (4) adapted to removably receive the filter member (13), said cavity being closable by a closing element (21) so as to retain said filter element (13) in the cup-shaped part (3).

13. The air filter device according to claim 12, characterized in that said cavity (4) comprises a guide element (10) for the insertion and positioning of the filter member (13) in the cavity (4) itself.

14. The air filter device according to claim 1, characterized in that said guide element is a pin (10) rising in the cavity (4), the filter member (13) having a through hole (12) to receive said pin (10).

15. The air filter device according to claim 1,characterized in that said casing (2) is connected to an outlet pipe (7).

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