Nasal filter

Abstract

A nasal filter (1) comprising a frame (2) with a right and a left frame portion (2a, 2b) dimensioned for placement inside a left and right nostril, respective, and optionally connected via a U-shaped bridge (4). Each frame portion (2a, 2b) comprises an anterior support section (6a) towards the front of the nose and a posterior support section (6b) towards the back of the nose, the support sections supporting a filter element (3). Resilient means (8,9) connect the anterior support section (6a) with the posterior support section (6b) for flexible change of distance between the anterior support section (6a) and the posterior support section (6b).

Claims

1. A nasal filter comprising a left and right frame portion dimensioned for placement inside a left and right nostril of a nose, respective; each frame portion comprising an anterior support section configured for being directed towards a front of the nose when the nasal filter is inserted into the nose; each frame portion being made from a flexible polymer material; and each frame portion comprising a posterior support section configured for being directed towards a back of the nose when the nasal filter is inserted into the nose; the anterior support section and the posterior support section supporting a filter element; each frame portion comprising resilient means connecting the anterior support section with the posterior support section for flexible change of distance between the anterior support section and the posterior support section; wherein a) the anterior support section has a medial segment and a lateral segment and extends from a medial side to a lateral side of the nose along an anterior inner part of the nose when inserted into the nose, and the posterior support section has a medial sector and a lateral sector and extends along a posterior inner part of the nose when inserted into the nose; the resilient means comprising a medial resilient member flexibly connecting the medial segment with the medial sector; whereby the medial sector, the medial resilient member, and the medial segment in combination form a medial side of the frame portion configured for being directed towards the septum when the nasal filter is inserted into a nose; the medial resilient member being configured for flexible change of distance between the medial segment and the medial sector; wherein the medial resilient member, when the nasal filter is in a relaxed state, comprises a medial bend as a resilient connection between the medial sector and the medial segment; wherein the medial bend has a predominant V-shape with a rounded bottom, the V-shape being formed by a first leg and a second leg connected to the rounded bottom, the first leg being connected to the medial sector and the second leg being connected to the medial segment in order for the V-shaped medial bend to resiliently connect the medial sector with the medial segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a straight or bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the medial bend extends outside the filter support plane when the nasal filter is in a relaxed state; or b) the anterior support section has a lateral segment, and the posterior support section has a lateral sector; the resilient means comprising a lateral resilient member flexibly connecting the lateral segment with the lateral sector; whereby the lateral sector, the resilient means, and the lateral segment in combination form a lateral side of the frame portion configured for being directed towards the lateral part of the nose when the nasal filter is inserted into a nose; the lateral resilient member being configured for flexible change of distance between the lateral segment and the lateral sector; wherein the lateral resilient member, when the nasal filter is in a relaxed state, comprises a lateral bend as a resilient connection between the lateral sector and the lateral segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a straight or bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the lateral bend extends outside the filter support plane when the nasal filter is in a relaxed state; or both a) and b).

2. A nasal filter according to claim 1, wherein the medial bend is directed downwards or upwards relatively to the filter; or wherein the lateral bend is directed downwards or upwards relatively to the filter; or both.

3. A nasal filter according to claim 2, wherein the medial bend is directed downwards and has a bottom when the nasal filter is inserted into a nose; or wherein the lateral bend is directed downwards and has a bottom when the nasal filter is inserted into a nose; or both.

4. A nasal filter comprising a left and right frame portion dimensioned for placement inside a left and right nostril of a nose, respective; each frame portion comprising an anterior support section configured for being directed towards a front of the nose when the nasal filter is inserted into the nose; each frame portion being made from a flexible polymer material; and each frame portion comprising a posterior support section configured for being directed towards a back of the nose when the nasal filter is inserted into the nose; the anterior support section and the posterior support section supporting a filter element; each frame portion comprising resilient means connecting the anterior support section with the posterior support section for flexible change of distance between the anterior support section and the posterior support section; wherein a) the anterior support section has a medial segment, and the posterior support section has a medial sector; the resilient means comprising a medial resilient member flexibly connecting the medial segment with the medial sector; whereby the medial sector, the medial resilient member, and the medial segment in combination form a medial side of the frame portion configured for being directed towards the septum when the nasal filter is inserted into a nose; the medial resilient member being configured for flexible change of distance between the medial segment and the medial sector; wherein the medial resilient member, when the nasal filter is in a relaxed state, comprises a medial bend as a resilient connection between the medial sector and the medial segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a straight or bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the medial bend extends outside the filter support plane when the nasal filter is in a relaxed state; wherein the anterior support section of each frame portion has a frontal point configured for being directed towards the front of the nose when the nasal filter is inserted into a nose; and the posterior support section of each frame portion has a backmost point configured for being directed towards the back of the nose when the nasal filter is inserted into a nose; the two frontal points and the two backmost points defining a reference plane with a normal vector perpendicular to the reference plane; wherein the medial bend is largely perpendicular to the reference plane; or b) the anterior support section has a lateral segment, and the posterior support section has a lateral sector; the resilient means comprising a lateral resilient member flexibly connecting the lateral segment with the lateral sector; whereby the lateral sector, the resilient means, and the lateral segment in combination form a lateral side of the frame portion configured for being directed towards the lateral part of the nose when the nasal filter is inserted into a nose; the lateral resilient member being configured for flexible change of distance between the lateral segment and the lateral sector; wherein the lateral resilient member, when the nasal filter is in a relaxed state, comprises a lateral bend as a resilient connection between the lateral sector and the lateral segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a straight or bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the lateral bend extends outside the filter support plane when the nasal filter is in a relaxed state; or both a) and b).

5. A nasal filter according to claim 4 wherein if the anterior support section has a medial segment, the medial bend is within a range of plus or minus 20 degrees from the normal vector of the reference plane.

6. A nasal filter according to claim 4 wherein if the anterior support section has a medial segment, the medial resilient member has a medial bend with a radius of curvature that has a direction forming an angle in the interval of 0-20 degrees with the normal vector.

7. A nasal filter according to claim 6, wherein if the anterior support section has a medial segment, the medial bend has a bottom and the radius of curvature at the bottom of the medial bend has a direction forming an angle in the interval of 0-20 degrees with the normal vector.

8. A nasal filter according to claim 1, wherein each frame portion is connected by a flexible bridge that is made from the same flexible polymer material as each frame portion and is integral with each frame portion, the bridge comprising a bottom and two legs extending from the bottom, for fastening the bridge across the columella of the nose and against the cartilage with one leg on either side of the medial septum of the nose; wherein the medial bend is part of or merges into the leg of the bridge.

9. A nasal filter according to claim 1, wherein the anterior support section has a lateral segment, and the posterior support section has a lateral sector; the resilient means comprising a lateral resilient member flexibly connecting the lateral segment with the lateral sector; whereby the lateral sector, the lateral resilient means, and the lateral segment in combination form a lateral side of the frame portion configured for being directed towards the lateral part of the nose when the nasal filter is inserted into a nose; the lateral resilient member being configured for flexible change of distance between the lateral segment and the lateral sector.

10. A nasal filter according to claim 1, wherein if the anterior support section has a lateral segment, the anterior support section of each frame portion has a frontal point configured for being directed towards the front of the nose when the nasal filter is inserted into a nose; and the posterior support section of each frame portion has a backmost point configured for being directed towards the back of the nose when the nasal filter is inserted into a nose; the two frontal points and the two backmost points defining a reference plane with a normal vector perpendicular to the reference plane; wherein the lateral bend is within a range of plus or minus 45 degrees from the normal vector of the reference plane.

11. A nasal filter according to claim 10, wherein if the anterior support section has a lateral segment, the lateral bend has a radius of curvature that has a direction forming an angle in the interval of 0-45 degrees with the normal vector.

12. A nasal filter according to claim 11, wherein if the anterior support section has a lateral segment, the lateral bend has a bottom and the radius of curvature at the bottom of the lateral bend has a direction forming an angle in the interval of 0-45 degrees with the normal vector.

13. A nasal filter comprising a left and right frame portion dimensioned for placement inside a left and right nostril of a nose, respective; each frame portion comprising an anterior support section configured for being directed towards a front of the nose when the nasal filter is inserted into the nose; each frame portion being made from a flexible polymer material; and each frame portion comprising a posterior support section configured for being directed towards a back of the nose when the nasal filter is inserted into the nose; the anterior support section and the posterior support section supporting a filter element; each frame portion comprising resilient means connecting the anterior support section with the posterior support section for flexible change of distance between the anterior support section and the posterior support section; wherein the anterior support section comprises a lateral segment and the posterior support section comprises a lateral sector; wherein a) the anterior support section has a medial segment and a lateral segment and extends from a medial side to a lateral side of the nose along an anterior inner part of the nose when inserted into the nose, and the posterior support section has a medial sector and a lateral sector and extends along a posterior inner part of the nose when inserted into the nose; both the lateral segment and the lateral sector being configured for placement against the lateral inner wall of the nostril, wherein the lateral segment and the lateral sector are disconnected by a gap between the lateral segment and the lateral sector; the resilient means comprising a medial resilient member flexibly connecting the medial segment with the medial sector; whereby the medial sector, the medial resilient member, and the medial segment in combination form a medial side of the frame portion configured for being directed towards the septum when the nasal filter is inserted into a nose; the medial resilient member being configured for flexible change of distance between the medial segment and the medial sector; wherein the medial resilient member, when the nasal filter is in a relaxed state, comprises a medial bend as a resilient connection between the medial sector and the medial segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a straight or bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the medial bend extends outside the filter support plane when the nasal filter is in a relaxed state; or b) the anterior support section has a lateral segment, and the posterior support section has a lateral sector; the resilient means comprising a lateral resilient member flexibly connecting the lateral segment with the lateral sector; whereby the lateral sector, the resilient means, and the lateral segment in combination form a lateral side of the frame portion configured for being directed towards the lateral part of the nose when the nasal filter is inserted into a nose; the lateral resilient member being configured for flexible change of distance between the lateral segment and the lateral sector; wherein the lateral resilient member, when the nasal filter is in a relaxed state, comprises a lateral bend as a resilient connection between the lateral sector and the lateral segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a straight or bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the lateral bend extends outside the filter support plane when the nasal filter is in a relaxed state; or both a) and b).

14. A nasal filter according to claim 1, wherein the filter element is dimensioned 3%-30% larger than an area spanned by the anterior and posterior support sections, and the filter element thereby extending outside the spanned area in order for the filter element to contact and tighten against the inner walls of the nostrils.

15. A nasal filter comprising a left and right frame portion dimensioned for placement inside a left and right nostril of a nose, respective; each frame portion comprising an anterior support section configured for being directed towards a front of the nose when the nasal filter is inserted into the nose; each frame portion being made from a flexible polymer material; and each frame portion comprising a posterior support section configured for being directed towards a back of the nose when the nasal filter is inserted into the nose; the anterior support section and the posterior support section supporting a filter element; each frame portion comprising resilient means connecting the anterior support section with the posterior support section for flexible change of distance between the anterior support section and the posterior support section; wherein if the anterior support section has at least one of: a medial segment, or a lateral segment, then the anterior support section has a frontal point configured for being directed towards the front of the nose when the nasal filter is inserted into a nose; and the posterior support section has a backmost point configured for being directed towards the back of the nose when the nasal filter is inserted into a nose; wherein the anterior support section has an anterior support surface for supporting the filter element; and wherein the posterior support section has a posterior support surface for supporting the filter element; wherein the anterior support surface is angled with an angle in the interval of 5 to 40 degrees relative to the posterior support surface when the angle is measured along a curved line from the backmost point to the frontal point in order for supporting the filter element in a bent state; wherein a) the anterior support section has a medial segment and a lateral segment and extends from a medial side to a lateral side of the nose along an anterior inner part of the nose when inserted into the nose, and the posterior support section has a medial sector and a lateral sector and extends along a posterior inner part of the nose when inserted into the nose; the resilient means comprising a medial resilient member flexibly connecting the medial segment with the medial sector; whereby the medial sector, the medial resilient member, and the medial segment in combination form a medial side of the frame portion configured for being directed towards the septum when the nasal filter is inserted into a nose; the medial resilient member being configured for flexible change of distance between the medial segment and the medial sector; wherein the medial resilient member, when the nasal filter is in a relaxed state, comprises a medial bend as a resilient connection between the medial sector and the medial segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the medial bend extends outside the filter support plane when the nasal filter is in a relaxed state; or b) the anterior support section has a lateral segment, and the posterior support section has a lateral sector; the resilient means comprising a lateral resilient member flexibly connecting the lateral segment with the lateral sector; whereby the lateral sector, the resilient means, and the lateral segment in combination form a lateral side of the frame portion configured for being directed towards the lateral part of the nose when the nasal filter is inserted into a nose; the lateral resilient member being configured for flexible change of distance between the lateral segment and the lateral sector; wherein the lateral resilient member, when the nasal filter is in a relaxed state, comprises a lateral bend as a resilient connection between the lateral sector and the lateral segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the lateral bend extends outside the filter support plane when the nasal filter is in a relaxed state; or both a) and b).

16. A nasal filter comprising a left and right frame portion dimensioned for placement inside a left and right nostril of a nose, respective; each frame portion comprising an anterior support section configured for being directed towards a front of the nose when the nasal filter is inserted into the nose; each frame portion being made from a flexible polymer material; and each frame portion comprising a posterior support section configured for being directed towards a back of the nose when the nasal filter is inserted into the nose; the anterior support section and the posterior support section supporting a filter element; each frame portion comprising resilient means connecting the anterior support section with the posterior support section for flexible change of distance between the anterior support section and the posterior support section; wherein the anterior support section of each frame portion has a frontal point configured for being directed towards the front of the nose when the nasal filter is inserted into a nose; and the posterior support section of each frame portion has a backmost point configured for being directed towards the back of the nose when the nasal filter is inserted into a nose; the two frontal points and the two backmost points defining a reference plane with a normal vector perpendicular to the reference plane; wherein the posterior support section has a medial sector and a lateral sector, where the medial sector is near or at the septum and the lateral sector near or at the lateral wall of the nostril when the nasal filter is inserted into the nose; wherein the posterior support section has a downwards or upwards slope in the direction from the medial sector towards the lateral sector; the downwards or upwards slope forming an angle in the interval of 45-85 degrees with the normal vector; wherein a) the anterior support section has a medial segment and a lateral segment and extends from a medial side to a lateral side of the nose along an anterior inner part of the nose when inserted into the nose, and the posterior support section extends along a posterior inner part of the nose when inserted into the nose; the resilient means comprising a medial resilient member flexibly connecting the medial segment with the medial sector; whereby the medial sector, the medial resilient member, and the medial segment in combination form a medial side of the frame portion configured for being directed towards the septum when the nasal filter is inserted into a nose; the medial resilient member being configured for flexible change of distance between the medial segment and the medial sector; wherein the medial resilient member, when the nasal filter is in a relaxed state, comprises a medial bend as a resilient connection between the medial sector and the medial segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a straight or bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the medial bend extends outside the filter support plane when the nasal filter is in a relaxed state; or b) the anterior support section has a lateral segment; the resilient means comprising a lateral resilient member flexibly connecting the lateral segment with the lateral sector; whereby the lateral sector, the resilient means, and the lateral segment in combination form a lateral side of the frame portion configured for being directed towards the lateral part of the nose when the nasal filter is inserted into a nose; the lateral resilient member being configured for flexible change of distance between the lateral segment and the lateral sector; wherein the lateral resilient member, when the nasal filter is in a relaxed state, comprises a lateral bend as a resilient connection between the lateral sector and the lateral segment; wherein the anterior support section has an anterior support surface for supporting the filter element; and the posterior support section has a posterior support surface for supporting the filter element, wherein the anterior support surface and the posterior support surface define a straight or bent filter support plane for the filter element; wherein the shape of the filter element follows this filter support plane when the nasal filter is in a relaxed state; wherein the lateral bend extends outside the filter support plane when the nasal filter is in a relaxed state; or both a) and b).

17. A nasal filter according to claim 1, wherein the filter element is planar.

Description

SHORT DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in more detail with reference to the drawings, where

(2) FIG. 1 is a photo of three nasal filters in different sizes;

(3) FIG. 2 illustrates a three dimensional view of a frame of a nasal filter in a) a skew perspective view, b) a front view, c) a side view and d) a back view;

(4) FIG. 3 illustrates one frame portion with a filter element in a) a side view and b) a top view;

(5) FIG. 4 illustrates a first alternative embodiment of a frame;

(6) FIG. 5 illustrates a second alternative embodiment;

(7) FIG. 6 is a stacked view of three different sized frames;

(8) FIG. 7 illustrates the same frame as in FIG. 2a with a reference plane for illustration of geometrical terminology;

(9) FIG. 8 illustrates an alternative embodiment showing a single frame portion with an upwards lateral bend and a downwards medial bend.

DETAILED DESCRIPTION/PREFERRED EMBODIMENT

(10) FIG. 1 shows a photograph of some prototypes in various sizes of a nasal filter 1, the nasal filter having a frame 2 and a filter element 3 attached to the frame 2.

(11) FIG. 2a is a perspective view of one embodiment of a frame 2 of a nasal filter. The frame 2 comprises a U-formed bridge 4 connecting the medial sides of a left frame portion 2a and a right frame portion 2b. The bridge 4 acts as a clip, or part of a clip, around the columella of the nose.

(12) FIGS. 2b, 2c, and 2d are different perspectives of the same frame as in FIG. 2a, namely a view from the front, side, and back, respectively.

(13) Each of the frame portions 2a, 2b comprises a support section 6 and a connector 7 connecting the bridge 4 with the support section 6. The support section 6 is that part of the frame 2 that supports the filter element 3. The bridge 4 acts as a clip around the columella of the nose; or the bridge 4 in combination with the connector 7 acts as a clip around the columella of the nose. The bridge 4 and the connector 7 are those parts of the frame 2 that clip around the cartilage of the septum and, when in use by a standing person, extend upwards and inwards along the septum of the nose. The support section 6 is arranged to support the filter element 3 that extends across the nostril. Typically, the support section 6 extends across the nostril or surrounds the nostril along the nostril wall in order to support the filter element 3. The support section 6 defines a plane for the filter element, actually a convex, bent plane. Alternatively, the plane could be straight or concavely bent. With reference to the embodiment of FIG. 1, it is seen that the area spanned by the support section 6 is designed to be smaller than the area of the filter element 3 such that the support section 6 does not necessarily touch the inner walls of the nostrils during use of the nasal filter 1, however, the filter element would touch the inner wall of the nostrils when the nasal filter is in proper use. The fact that the filter material extends outside the support section 6 is not strictly necessary but usually is more comfortable.

(14) As the filter 1, when in use, has a typical orientation when being used by a standing person, it is appropriate to use the terms upwards and downwards, above and below for the relative arrangements of the parts of the filter without thereby introducing ambiguity, as it is also customary to describe the nose of a person with upper and lower parts, despite the fact that a person can be lying down or hanging upside down. The terms anterior or posterior are used for those parts that are configured to be placed towards the anterior or posterior part of the nostril. The terms medial and lateral are used for those parts of the nasal filter that are directed towards the medial part or lateral part of the nose, respectively.

(15) The support section 6 comprises an anterior support section 6a that supports the filter element 3 at the anterior part of the nostril, and the support section 6 has a posterior support section 6b that supports the filter element 3 at the posterior part of the nostril. The anterior support section 6a adjusts to different noses and guides the device into its correct position by being flexible due to the resilient means described in more detail in the following.

(16) In the following, a reference plane 23 is referred to as illustrated in FIG. 7. The reference plane 23 is defined by the two frontal points 21a, 21b of the anterior support sections 6a, and the two most backward points 22a, 22b of the posterior support sections 6b. The term downwards direction is used for a direction perpendicular to the reference plane 23 and is meant to be towards the nose entrance for a normally standing person when using the nasal filter, although it is pointed out that noses differ and downwards does not necessarily mean vertically downwards for a standing person. The term upwards is used for the opposite direction. A direction perpendicular to the reference plane 23 is defined by the normal vector 29 of the reference plane 23, the normal vector 29 defining the orientation of the reference plane 23 in space.

(17) As illustrated in FIG. 3b, the anterior support section 6a comprises a medial segment 18a and a lateral segment 18b where the medial segment 18a is near or at the septum, when the nasal filter is inserted into the nose, and the lateral segment 18b is near the lateral wall of the nostril. The posterior support section 6b has a medial sector 16a and a lateral sector 16b, where the medial sector 16a is near or at the septum when the nasal filter is inserted into the nose, and the lateral sector 16b is near the lateral wall of the nostril.

(18) With reference to FIG. 2a, between the anterior support section 6a and the posterior support section 6b, a lateral resilient member 8 is provided, comprising a lateral bend 8 as part of a lateral side of the frame portion 2a, 2b. As best seen in FIG. 3b, the lateral resilient member 8 with the lateral bent 8 is configured for flexible change of distance between the lateral segment 18b and the lateral sector 16b. In the shown embodiment, the lateral bend 8 connects the lateral segment 18b with the lateral sector 16b.

(19) Also, between the anterior support section 6a and the posterior support section 6b, a medial resilient member 9 is provided comprising a medial bend 9 as part of a medial side of the frame portion 2a, 2b. As best seen in FIG. 3b, the medial resilient member 9 with the medial bent 9 is configured for flexible change of distance between the medial segment 18a and the medial sector 16a. In the shown embodiment, the medial bend 9 connects the medial segment 18a with the medial sector 16a.

(20) With reference to FIG. 2a, the lateral bend 8 connects the anterior support section 6a and the posterior support section 6b on the lateral side of the frame portion 2a, 2b. Likewise, the medial bend 9 connects the anterior support section 6a and the posterior support section 6b on the medial side of the frame portion 2a, 2b. In the shown drawing, it appears that the medial bend 9 is part of the connector 7. The bends 8, 9 give the support section 6 a high flexibility as compared to a support section that would be formed by a closed ring as disclosed in GB2289846.

(21) The concavity of the illustrated lateral bend 8 is shaped predominantly circular, although this regularity is not necessary. The illustrated concavity of the medial bend 9 has a predominant V-shape with rounded bottom, although this regularity is not necessary, thus, resembling the advantages of a cone-like structure in terms of stability combined with the minimalism of a flat structure in order to utilise the best of both structures. Whereas the lateral bend 8 provides a certain degree of flexibility between the anterior support section 6a and the posterior support section 6b and at the same time stability against wobbliness, the medial bend 9 provides a certain degree of flexibility between the anterior support section 6a and the posterior support section 6b and at the same time stability along the septum.

(22) Both bends 8 and 9 are shown as being directed substantially downwards relatively to the support section 6 and relatively to the reference plane 23, which however is not strictly necessary, as one of these or both could as well be bent upwards, although the downwards bends 8, 9 are believed to be more comfortable for the user. It is pointed out that the term downwards means from the support section 6 in the direction towards the lower end of the nose, where the bridge bends around the columella. As best illustrated in FIGS. 2b and 2c with additional reference to FIG. 7, the direction of the radius of curvature 27 in the bottom of the lateral bend has a direction which has an angle V with the normal 29 of the reference plane, the angle V being 0-45 degrees, for example 10-45 degrees. Thus, the direction of the lateral bend is primarily downwards, although it could alternatively be upwards or a combination of an upwards lateral bend and a downwards lateral bend. As an example, in case that the anterior support section 6a and the posterior support section 6b as well as the lateral bent 8 are in a common plane, all the radii of curvature for the bend would be in this plane. The radius of curvature at the bottom of the bend would have an angle with the normal of the reference plane given by 90 degrees minus the angle between the normal vector of the reference plane and the normal vector of such plane.

(23) The bends 8, 9 result in the filter element 3 being supported only in the front part of the nostril by the anterior support section 6a and in the back part of the nostril by the posterior support section 6b, whereas there is a region between the anterior support section 6a and the posterior support section 6b where the filter element 3 is not supported. The effect is a better adjustment of the filter element 3 inside the nose, resulting in a better tightness of the filter element 3 in the nostril. It increases the overall comfort of the device and helps in securing the device along the curvature of the nasal cavity. Advantageously in this connection, the filter element 3 has a low stiffness and is easily bendable when the frame 2 is inserted into the nose and the anterior support section 6a and the posterior support section 6b are pushed towards each other in order to adjust to the shape of the nostril.

(24) The flexibility of the frame portions 2a, 2b in the direction from the anterior support section 6a to the posterior support section 6b, due to the lateral bend 8, depends on the depth of the lateral bend 8 apart from other parameters such as the material stiffness and its thickness. The depth is defined as follows with reference to FIG. 7. On the transition between the lateral bend 8 and the anterior support section 6a, there is a first point 8a of largest convex curvature, and on the transition between the lateral bend 8 and the posterior support section 6b, there is a second point 8b of largest convex curvature; these two points define a line 25. In case that the lateral bend 8 has a part with constant curvature, the first point 8a and the second point 8b are defined as the midpoints of the arch having constant curvature.

(25) The depth of the lateral bend 8 is thus defined as the distance d between the line 25 and the most downward point 8c of the lateral bend 8 when measured along a direction 26 perpendicular to the reference plane 23, which is the direction given by the normal vector 29. Such a distance d is at least 5% and typically between 10% and 30% of the distance D between the foremost point 21b of the anterior support section and the backmost point 22b of the posterior support section. In less mathematical terms, the depth d of the lateral bend is typically between 10% and 30% of the length D of the frame portion 2a,b that is placed in the nose. For the medial bend 8, the depth is much larger, typically, between 10% and 80% of the length of the frame portion 2a,b.

(26) The directions of the medial bend 9 and the lateral bend 8 are typically substantially downwards, that is, largely perpendicular to the reference plane 23. However, the direction of the lateral bend 8 may deviate from the downward direction in order to assist in a better fitting of the nasal filter in the nose of the user. As is best seen in FIG. 2b, in the presented embodiment, the direction as illustrated by the skew arrow 11 of the lateral bend 8 is not truly downwards like the normal vector 29 but only substantially downwards towards the columella in that the lateral bend 8 bends slightly towards the lateral parts of the nose, which makes it flexible not only in the direction from the front to the back of the nostril but also sideways, while still maintaining a structural stability in the nose. It is pointed out for sake of completeness that the illustrated arrow 11 in FIG. 2b has the same direction as the illustrated arrow 27 for the direction of the radius of curvature in the bottom of the lateral bend in FIG. 2c

(27) Also best seen in FIG. 2b, the bridge 4 is substantially U-formed with a flat bottom 12 and legs 14 in order to receive the lowest part of the septum of the nose between the legs 14. Thereby, the bridge 4 is least visible, especially, when the frame is made in a transparent material. The bridge 4 has a first width 13a between the legs proximal to the bottom 12, which is larger than a second width 13b between the legs 14 distal to the bottom 4. Thus, the curvature from the bottom 12 of the U-shaped bridge changes from concavity into convexity in the upwards direction along the legs 14. This is advantageous for securing the device in the nose and to the septum without impeding air flow. The U-shaped bridge ads slight pressure to the septum wall for holding frame 2 in its correct position and keeping it in position during exercise and breathing.

(28) As it appears best from FIG. 2c, the upper surface 6a of the anterior support section 6a and the upper surface 6b of the posterior support section 6b are mutually angled with a mutual angle V, for example of between 5 and 45 degrees, as it is shown in greater detail in the side view of FIG. 3a. This results in the filter element 3 being bent from the anterior to the posterior relatively to a horizontal plane 23. The shape is useful in guiding the user when inserting the nasal filter and placing it in a correct position. It also helps the user in placing the nasal filter correctly along the inner walls of the nostrils, thereby minimising gaps despite the curvature of the nasal cavity. The feature also ads to the flexibility of the nasal filter, which is important for comfort experienced by the user and the tightness of the filter element 3 against the inner walls of the nostrils.

(29) As also illustrated in FIG. 2c, the legs 14 of the U-shaped bridge 4 need not necessarily be straight but may curve between the bottom 12 of the bridge 4 and the support section 6. This curvature is, typically, substantially in a plane 15 parallel to the symmetry plane 15 between the left frame portion 2a and the right frame portion 2b, the symmetry plane being illustrated in FIG. 2d. This curvature of the legs 14 in a plane 15 parallel to the symmetry plane 15 helps as a guide when inserting the filter and assists in positioning the device in the desired position, for example such that the bridge is least visible. The leg 14 in combination with the bend 9 resembles a shape as the letter Y.

(30) As it also appears from FIG. 2b in comparison to FIG. 7, the legs 14 of the U-shaped bridge 4 are typically not perpendicular to the reference plane 23 but have a small angle of less than 90 degrees, advantageously an angle of 0 to 10 or 10 to 20 or 20 to 30, for example 5 to 10 or 5 to 20, degrees with the normal 29 of the reference plane 23. Such an angle of around 5 or 10 or 15 degrees from the normal 29 to the reference plane 23 results in a better fit of the frame in the nose. In case that the legs 14 are provided in a plane 15 parallel to the symmetry plane 15, the angle, with a slight exaggeration indicated as u in FIG. 2d, is measured from this plane 15. It may have a direction on either side of this plane 15.

(31) FIG. 3b shows a top view of the filter 3 on the support 6. The lateral dimensions of the filter element 3 are larger than the area spanned by the support section 6, such that the filter element 3 extends farther towards the walls of the nostrils than the support section 6 in order for the filter element 3 to tighten against the inner walls of the nostrils. For example, the filter element extends between 0.5 and 1.5 mm outside the support section 6. The larger size of the filter element 3 assists in closing gaps between the frame 2 and the inner walls of the nostrils as to accommodate small nasal cavity variations among people; further, depending on the filtering element, it also increases the tolerance and overall comfort of the embodiment, because it works as a cushioning mechanism.

(32) To a certain extend, this principle is known from the initially mentioned publication European patent EP2089115B1. However, the area spanned by the support section 6 is larger relatively to the area of the filter element in that the filter element advantageously is only between 3% and 30% larger than the area spanned by the support section 6, whereas in EP2089115B1, the area of the filter element is more than 100% larger (more than twice as large).

(33) As illustrated in FIG. 3b, the posterior support section 6b has a medial sector 16a and a lateral sector 16b, where the medial sector 16a is near or at the septum when the nasal filter is inserted into the nose and the lateral sector 16b is near the lateral wall of the nostril. As indicated in FIG. 2d, the posterior support section 6b has a downward slope in the direction from the medial sector 16a towards the lateral sector 16b. This downward slope is typically 45-85 degrees, for example in the range of 70-80 degrees, relatively to the normal 29 of the reference plane 23. This slope increases the flexibility of the device and allows the users to be able to touch their noses without feeling discomfort. Likewise, optionally, the anterior support section can be sloped for increasing the comfort.

(34) FIG. 4 illustrates one possible alternative embodiment, showing the alternative frame 2 from a skew front view. The frame 2 comprises only a medial bend 9 and not a lateral bend. The anterior support section 6a merges with the posterior support section 6b on the lateral sector 16b of the posterior support section 6b. The downwards slope of the support section 6 has a typical angle of 45-85 degrees with the normal vector 29; however, it is more pronounced with a steeper angle from the medial sector 16a to lateral sector 16b than illustrated in the model as shown in FIG. 2d. In this embodiment, primarily, the medial bend 9 assists in flexibility of the frame 2 in the direction from the front to the back of the nostril.

(35) FIG. 5 illustrates a skew view from the side of a further alternative embodiment of a frame 2 for a nasal filter. In this embodiment, the frame 2 comprises medial bends 9 but not lateral bends. Instead, the lateral sector 16b of the posterior support section 6b is not directly connected to the anterior support section 6a but decoupled from the anterior support section 6a. The anterior support section 6a has a medial segment 18a configured for placement towards the septum and a lateral segment 18b configured for placement against the lateral inner wall of the nostril. The lateral segment 18b of the anterior support section 6a and the lateral sector 16b of the posterior support section 6b are not directly connected but only indirectly through the medial segment 18a, the medial bend 9 and the medial sector 16a. A gap 17 is provided between lateral segment 18b of the anterior support section 6a and the lateral sector 16b of the posterior support section 6b. In the shown embodiment, lateral segment 18b of the anterior support section 6a has a first end 19 and the lateral sector 16b of the posterior support section 6b has a second end 20 on either side of the gap 17. The open structure provided by the disconnection between the anterior support section 6a and the posterior support section 6b on the lateral side of the frame portion provides flexibility and adaptability for the frame 2.

(36) As a further alternative, the lateral sector 16b of the posterior support section 6b could be substantially shorter than illustrated, for example as short such that it ends at the indicated end point of the arrow 28.

(37) Instead of having a bend on the medial side and a gap on the lateral side, this could be reversed in that the medial side is built up similar to the illustrated lateral side with the gap 17, and the lateral side has a bend instead, much like the bend as illustrated in FIG. 2a.

(38) FIG. 6 shows a series of frames with different sizes graphically superimposed on each other. The constructed image illustrates that, in these embodiments, the shapes of the frames are not directly scaled, but the shapes of the frames are adjusted according to the size. Especially, the medial sector 16a of the posterior support section 6b has a different shape in dependence on the size of the frame 2. For increasing size, the medial sector 16a bends relatively more outwards for the larger frames than for the smaller frames. Thus, the angle between the lateral sides of the two frame portions 2a, 2b is larger for the larger models than for the smaller.

(39) FIG. 8 illustrates an embodiment, where the lateral bend 8 is bending upwards, whereas the medial bend 9 is bending downwards. Only the right frame portion 2b is shown for reasons of simplicity. In this case, it may be advantageous that the filter element is within the frame and does not extend outside the frame.

(40) Some typical, although not limiting intervals for dimensions for adult use are given in millimetres (mm) in the following, whereas it is pointed out that the dimensions for nasal filters for children would be smaller. The dimensions are given for three types of filters, small/medium/large: depth d of the lateral bend 8 as measured from line 25 (see FIG. 7): 1.5-5 or 2.5-4; length D from frontal point 22a, 22b to backmost point 21a, 21b (see FIG. 7): 10-14/12-16/15-20 or 11-13/14-16/17-20; the depth L of the medial bend 9 as measured from the bottom of the bent to the reference plane 23 (see FIG. 7): 4-8/5-8/6-9 or 5-8/6-8/6-9; the width 13a near the bottom 12 of the U-shaped bridge 4 (see FIG. 2b): 4-6/5-7/5-7 the width 13b between the legs 14 remote from the bottom 12 of the U-shaped bridge 4 (see FIG. 2b): 3-5/4-6/4-6 width W of the frame as illustrated in FIG. 2b: 14-21/16-22/19-26 or 15-20/16-21/19-22; overall height H of the nasal filter as illustrated in FIG. 2b: 8-14/10-15/12-17 or 10-14/14-15/14-16.

(41) The filter element is advantageously a woven or non-woven mesh type filter. A variety of methods of attaching the filter element 3 to the support element 6 exist, including but not limited to gluing, welding, melting, laser techniques and casting.