# Patent

## Title
Custom fitted mask and method of forming same

## Abstract

According to one embodiment of the invention, a method of forming a custom fitted mask includes transitioning a mask blank including a thin sheet of deformable material from a non-deformable state into a deformable state. The mask blank is applied against at least a portion of a user's face surrounding the user's nostrils while the mask blank is in the deformable state. The mask blank is deformed against the portion of the user's face to cause the mask blank to conform substantially optimally to the user's unique bone structure and facial features, the mask blank once conformed substantially optimally to the user's unique bone structure and facial features becoming the custom fitted mask. The custom fitted mask is allowed to transition from the deformable state into the non-deformable state for use.

## Background
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to masks for use in medical or other clinical applications, and more particularly to a custom fitted mask and method of forming same.
BACKGROUND OF THE INVENTION
Many people experience breathing problems on a recurring basis, which often results in sleep disordered breathing (i.e. difficulty sleeping, snoring, or other more serious conditions such as obstructive sleep apnea). As technology advances, people with such breathing problems demand increased performance and comfort. Previous devices for improving a user's breathing have included custom fitted masks that help deliver air or another suitable gas to the user's nose at positive pressure to help force open the user's breathing passage and thus improve the user's breathing. However, previous masks may be relatively expensive due to the expertise often required to design, manufacture, and fit the masks to each particular user. Furthermore, previous masks have often been fitted to the user's unique bone structure and facial features rather poorly, if at all. As a result, previous masks have often failed to adequately prevent leakage from around the perimeter of the mask, have caused discomfort for users, and have been relatively ineffective in treating breathing problems such as sleep disordered breathing.
SUMMARY OF THE INVENTION
According to the present invention, problems and disadvantages associated with previous custom fitted masks and methods for forming them may be reduced or eliminated.
According to one embodiment, a method of forming a custom fitted mask includes transitioning a mask blank including a thin sheet of deformable material from a non-deformable state into a deformable state. The mask blank is applied against at least a portion of a user's face surrounding the user's nostrils while the mask blank is in the deformable state. The mask blank is deformed against the portion of the user's face to cause the mask blank to conform substantially optimally to the user's unique bone structure and facial features, the mask blank once conformed substantially optimally to the user's unique bone structure and facial features becoming the custom fitted mask. The custom fitted mask is allowed to transition from the deformable state into the non-deformable state for use.
According to another embodiment, a custom fitted mask includes a thin sheet of deformable material that has been formed and fitted to a portion of a user's face surrounding the user's nostrils to conform substantially optimally to the user's unique bone structure and facial features. The portion of the user's face includes only soft cartilaginous portions of the user's nose and portions of the user's face on either side of and below the soft cartilaginous portions of the user's nose. The portion of the user's face excludes hard bony portions of the user's nose generally above the soft cartilaginous portions of the user's nose.
According to another embodiment, a mask blank for using in forming a custom fitted mask includes a thin sheet of deformable material capable of being transitioned from a non-deformable state into a deformable state, applied against at least a portion of a user's face surrounding the user's nostrils while the mask blank is in the deformable state, and deformed against the portion of the user's face to cause the mask blank to conform substantially optimally to the user's unique bone structure and facial features. The mask blank once conformed substantially optimally to the user's unique bone structure and facial features becomes the custom fitted mask.
Certain embodiments of the present invention may provide one or more technical advantages. For example, in certain embodiments, a custom fitted mask may be formed and fitted to a particular user relatively quickly and easily, with little expertise required on the part of the clinical professional who is forming and fitting the mask, typically resulting in improved efficiency for the clinical professional and reduced cost to the user. Also in contrast to prior masks, in certain embodiments, a custom fitted mask may be formed and fitted to a particular user so as to conform substantially optimally to the user's unique facial structure and features. As a result, the custom fitted mask of the present invention may provide improved fit, reduced leakage, increased comfort, and better performance, whether in treating breathing problems such as sleep disordered breathing or for any other suitable purpose for which the custom fitted mask is used. Certain embodiments of the present invention may provide some, all, or more of these advantages. Certain embodiments may provide one or more other advantages, one or more of which may be readily apparent to those skilled in the art based on the figures, descriptions, and claims included herein.



BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and advantages thereof, reference is made to the following descriptions taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features and wherein:
FIG. 1 illustrates an example system for improving a user's breathing including a custom fitted mask;
FIG. 2 illustrates a larger view of an example custom fitted mask;
FIG. 3 illustrates an interior view of an example custom fitted mask;
FIG. 4 illustrates another example custom fitted mask that further covers the user's mouth:
FIG. 5 illustrates another example custom fitted mask that further covers the user's mouth and at least a portion of the user's face below the user's chin; and
FIG. 6 illustrates an example method of forming a custom fitted mask for a particular user.



DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an example system 10 for improving a user's breathing including an example custom fitted mask 12. Mask 12 includes a perimeter 14 and holes 16, one for each of the user's nostrils, into which fittings 18 may be inserted during or after formation and fitting of mask 12. Fittings 18 may be used to couple mask 12 to an external system 20, such as a continuous positive air pressure (CPAP) system, for supplying air or another gas to the user's nose at positive pressure to help open the user's breathing passage and thereby improve the user's breathing. For example, system 10 may include tubes 22 that snap onto, are force fitted onto, or otherwise couple to fittings 18. Mask 12 may include buckles or other devices 24 to couple mask 12 to one or more straps 26, which may help secure mask 12 to the user's face during use. Devices 24 may be coupled to mask 12 during or after formation and fitting of mask 12. Mask 12 may include holes for receiving devices 24 for coupling mask 12 to one or more straps 26 for securing mask 12 to the user's face. Although straps 26 are described as an example, mask 12 being may be secured in any appropriate manner.
Mask 12 is preferably formed and fitted to the user's face so as to conform substantially optimally to the user's unique bone structure and facial features, including at least a portion of the user's nose surrounding the user's nostrils. In one embodiment, mask 12 covers only the soft cartilaginous portions of the user's nose and portions of the user's face to the sides of and below the soft cartilaginous portions of the user's nose, but does not cover the hard bony portions of the user's nose generally above the soft cartilaginous portions of the user's nose. This may allow custom fitted mask 12 to better conform to the unique shape of the user's face and, as a result of the improved fit, to provide reduced leakage, increased comfort, and better performance. FIG. 2 illustrates a larger view of an example mask 12, while FIG. 3 illustrates an interior view of an example mask 12. As best shown in FIG. 3, as described above, mask 12 may include holes for receiving devices 24 for coupling mask 12 to one or more straps 26 for securing mask 12 to the user's face.
In another embodiment, as illustrated in FIG. 4, mask 12 covers at least a portion of the user's nose surrounding the user's nostrils (which may or may not be limited to the soft cartilaginous portions of the user's nose and portions of the user's face to the sides of and below the soft cartilaginous portions of the user's nose) and additionally covers the user's mouth to prevent leakage from the user's mouth. Such a mask 12 may be formed from a single sheet of deformable material or may be formed from multiple sheets of deformable material (e.g., a first covering the user's nose and a second covering the user's mouth) coupled to one another using one or more screws, clips, glue, the same or a different deformable material that is chemically bonded to the sheets of deformable material, or another appropriate fastening technique. Where multiple sheets of deformable material are used, the multiple sheets may be customized for the user at the same or at different times. For example, a first sheet may be customized to cover at least a portion of the user's nose at a first time and, if appropriate, a second sheet may be customized to cover the user's mouth at a subsequent second time and then coupled to the first sheet.
In another embodiment, as illustrated in FIG. 5, mask 12 covers at least a portion of the user's nose surrounding the user's nostrils (which may or may not be limited to the soft cartilaginous portions of the user's nose and portions of the user's face to the sides of and below the soft cartilaginous portions of the user's nose), covers the user's mouth, and additionally covers at least a portion of the user's face below the user's chin to better secure mask 12 to the user's face. Such a mask 12 may be formed from a single sheet of deformable material or may be formed from multiple sheets of deformable material (e.g., a first covering the user's nose and a second covering the user's mouth and chin or a first covering the user's nose, a second covering the user's mouth, and a third covering the user's chin) coupled to one another using one or more screws, clips, glue, the same or a different deformable material that is chemically bonded to the sheets of deformable material, or another appropriate fastening technique. Where multiple sheets of deformable material are used, the multiple sheets may be customized for the user at the same or at different times. For example, a first sheet may be customized to cover at least a portion of the user's nose at a first time and, if appropriate, a second sheet may be customized to cover the user's mouth and chin at a subsequent second time and then coupled to the first sheet.
In one embodiment, mask 12 begins as a deformable mask blank made of a suitable deformable material. For example, a mask blank may include a suitable thermoplastic polymer and suitable fillers, stabilizers, coloring agents, antioxidants, antimicrobial agents, or other materials. As another example, a mask blank may include a light curing material such as the material sold under the name TRIAD by DENTSPLY INTERNATIONAL INC. Such materials are well known in various contexts to those skilled in the art.
In a more particular embodiment, a mask blank may include, possibly in addition to one or more other materials, one or more of the polycaprolactone polymers or other aliphatic polyesters that are described in U.S. Pat. Nos. 4,784,123 and 5,112,225 and product literature of UNION CARBIDE CORPORATION. One or more polycaprolactone polymers may have the formula: 




where R is an aliphatic hydrocarbon and n may range between approximately 300 to approximately 650. The TONE polycaprolactone polymers are described in U.S. Pat. Nos. 4,784,123 and 5,112,225 and product literature of UNION CARBIDE CORPORATION as including homopolymers, block copolymers, graft copolymers, or other polymers containing epsilon-caprolactone. Polymerization may be initiated using a diol, for example and without limitation, ethylene glycol, diethylene glycol, neopentyl glycol, butane diol, hexane diol, or any other appropriate diol. The diol may have the formula:

HO—R—OH  (2)

where R is an aliphatic hydrocarbon. Where a mask blank includes one or more polycaprolactone polymers, any suitable polycaprolactone polymer or polymers may be used. In general, polycaprolactone polymers may display desirable dimensional stability and thermoplasticity during cooling, biocompatibility, and a variety of other characteristics making them suitable for use in forming the mask blanks described herein.

In one embodiment, a mask blank may include a thin sheet of deformable material that is already contoured in the shape of a portion of a generic user's face, including at least the portion of the generic user's nose surrounding the generic user's nostrils. For example, the mask blank may be sized and shaped such that it will cover only the soft cartilaginous portions of the generic user's nose and portions of the generic user's face to the sides of and below the soft cartilaginous portions of the generic user's nose, but will not cover the hard bony portions of the generic user's nose generally above the soft cartilaginous portions of the generic user's nose. In another embodiment, a mask blank may include a thin sheet of deformable material that is substantially flat except for a depression sufficient to accommodate a generic user's nose, including at least the portion of the generic user's nose surrounding the user's nostrils. In another embodiment, a mask blank may include a thin sheet of deformable material that is substantially flat over its entire surface and does not include any depressions. Thin sheets of an appropriate deformable material may be obtained, for example, from CHESAPEAKE MEDICAL PRODUCTS, INC. In all cases, a mask blank may include pre-formed holes positioned according to the position of a generic user's nostrils. Mask blanks may be formed using an injection molding process (i.e. deformable material is placed into an injection molding machine while in a liquid state), using a pressing process (i.e. deformable material is placed into a press while in a deformable state), or using any other suitable technique. Mask blanks may be sized for various classes of generic users, for example, large for men, medium for women, and small for children. In one embodiment, mask blanks may be mass produced quickly, inexpensively, and with high quality and uniformity. Mask blanks may include fittings 18, devices 24, or any other suitable features.
To form and fit mask 12 for a particular user using the mask blank, the mask blank is placed in a deformable state. For example, where the deformable material of the mask blank includes one or more polycaprolactone polymers, the mask blank may be heated in a microwave oven, in water or other non-solvent neutral liquid, or in any other suitable manner to between approximately 140° F. and approximately 180° F. so as to place the mask blank in a deformable state. If desired, features such as fittings 18 and devices 24 may be coupled to the mask blank at this time if such features are not already coupled to the mask blank. The deformable material may chemically bond to features such as fittings 18 and devices 24 while the mask blank is in a deformable state to produce an integral unit. While in a deformable state, the mask blank is brought in contact with the user's face, including at least a portion of the user's nose surrounding the user's nostrils. The mask blank is then pressed against or otherwise allowed to conform to the user's unique bone structure and facial features to form mask 12. As the deformable material cools and hardens, mask 12 solidifies and will retain its custom fitted shape. Before or after the deformable material solidifies into its final custom fitted shape, mask 12 is removed from the user's face and is ready for use, for example, in treating sleep disordered breathing.
As described above, mask 12 is preferably formed and fitted to the user's face so as to conform substantially optimally to the user's unique bone structure and facial features, including at least a portion of the user's nose surrounding the user's nostrils. In one embodiment, mask 12 covers only the soft cartilaginous portions of the user's nose and portions of the user's face to the sides of and below the soft cartilaginous portions of the user's nose, but does not cover the hard bony portions of the user's nose generally above the soft cartilaginous portions of the user's nose. This may allow custom fitted mask 12 to better conform to the unique shape of the user's face and, as a result of the improved fit, to provide reduced leakage, increased comfort, and better performance. In another embodiment, mask 12 covers at least a portion of the user's nose surrounding the user's nostrils (which may or may not be limited to the soft cartilaginous portions of the user's nose and portions of the user's face to the sides of and below the soft cartilaginous portions of the user's nose) and additionally covers the user's mouth to prevent leakage from the user's mouth. In another embodiment, mask 12 covers at least a portion of the user's nose surrounding the user's nostrils (which may or may not be limited to the soft cartilaginous portions of the user's nose and portions of the user's face to the sides of and below the soft cartilaginous portions of the user's nose), covers the user's mouth, and additionally covers at least a portion of the user's face below the user's chin to better secure mask 12 to the user's face.
Although mask 12 is described primarily for use in treating breathing problems such as sleep disordered breathing, the present invention contemplates mask 12 being used or for any other suitable purpose for which a custom fitted mask may be used. As just one example, mask 12 may be used in delivering anesthetics during surgery or another medical procedure.
FIG. 6 illustrates an example method of forming a custom fitted mask 12 for a particular user. The method begins at step 100, a mask blank suitable for the user is placed in a deformable state. At step 102, if desired, features such as fittings 18 and devices 24 may be coupled to the mask blank if such features are not already coupled to the mask blank. At step 104, while the mask blank is in a deformable state, the mask blank is brought in contact with the user's face, including at least a portion of the user's nose surrounding the user's nostrils. At step 106, the mask blank is pressed against or otherwise allowed to conform to the user's unique bone structure and facial features to form mask 12. At step 108, as the deformable material cools and hardens, mask 12 solidifies in its final custom fitted shape. At step 110, mask 12 is removed from the user's face and is ready for use, for example, in treating sleep disordered breathing.
Although the present invention has been described above in connection with several example embodiments, it should be understood that a plethora of changes, substitutions, variations, alterations, transformations, and modifications may be suggested to one skilled in the art, and it is intended that the present invention encompass such changes, substitutions, variations, alterations, transformations, and modifications as fall within the spirit and scope of the appended claims.

## Claims

1. A method of forming a custom fitted mask, comprising:
transitioning a mask blank comprising a thin sheet of deformable material from a non-deformable state into a deformable state; 
applying the mask blank against at least a first portion of a user's face surrounding the user's nostrils while the mask blank is in the deformable state; 
deforming the mask blank against the first portion of the user's face to cause the mask blank to conform substantially optimally to the user's unique bone structure and facial features, the mask blank once conformed substantially optimally to the user's unique bone structure and facial features comprising the custom fitted mask; and 
allowing the custom fitted mask to transition from the deformable state into the non-deformable state for use.

2. The method of claim 1, wherein the mask blank comprises a thin sheet of deformable material that is already contoured in the shape of a first portion of a generic user's face surrounding the generic user's nostrils.

3. The method of claim 1, wherein the mask blank comprises a thin sheet of deformable material that is already contoured in the shape of a first portion of a generic user's face surrounding the generic user's nostrils, the first portion of the generic user's face comprising only soft cartilaginous portions of the generic user's nose and portions of the generic user's face on either side of and below the soft cartilaginous portions of the generic user's nose and excluding hard bony portions of the generic user's nose generally above the soft cartilaginous portions of the generic user's nose.

4. The method of claim 1, wherein the mask blank comprises a thin sheet of deformable material that is substantially flat except for a depression sufficient to accommodate at least a portion of a generic user's nose surrounding the generic user's nostrils.

5. The method of claim 1, further comprising:
applying the mask blank against at least a second portion of the user's face surrounding the user's mouth while the mask blank is in the deformable state; and 
deforming the mask blank against the second portion of the user's face to cause the mask blank to conform substantially optimally to the user's unique bone structure and facial features, the mask blank once conformed substantially optimally to the user's unique bone structure and facial features comprising the custom fitted mask.

6. The method of claim 5, wherein:
the mask blank comprises a first portion for applying to the first portion of the user's face and a second portion for applying to the second portion of the user's face; and 
the method further comprises coupling the first portion of the mask blank to the second portion of the mask blank in forming the custom fitted mask.

7. The method of claim 5, further comprising:
applying the mask blank against at least a third portion of the user's face under the user's chin while the mask blank is in the deformable state; and 
deforming the mask blank against the third portion of the user's face to cause the mask blank to conform substantially optimally to the user's unique bone structure and facial features, the mask blank once conformed substantially optimally to the user's unique bone structure and facial features comprising the custom fitted mask.

8. The method of claim 7, wherein:
the mask blank comprises a first portion for applying to the first portion of the user's face and a second portion for applying to the second and third portions of the user's face; and 
the method further comprises coupling the first portion of the mask blank to the second portion of the mask blank in forming the custom fitted mask.

9. The method of claim 1, wherein the mask blank comprises an injection molded mask blank.

10. The method of claim 1, wherein the mask blank comprises holes, one for each of the user's nostrils, into which fittings have been inserted for coupling the custom fitted mask to an external gas supply system.

11. The method of claim 1, wherein the mask blank comprises holes for receiving devices for coupling the custom fitted mask to one or more straps for securing the custom fitted mask to the user's face.

12. The method of claim 1, wherein the deformable material comprises a thermoplastic polymer and the mask blank is heated to transition the mask blank into the deformable state.

13. The method of claim 12, wherein the thermoplastic polymer comprises a polycaprolactone polymer.

14. The method of claim 1, wherein the custom fitted mask when in use is adapted to cover a portion of the user's face surrounding the user's nostrils, the portion of the user's face comprising only soft cartilaginous portions of the user's nose and portions of the user's face on either side of and below the soft cartilaginous portions of the user's nose but does not cover hard bony portions of the user's nose generally above the soft cartilaginous portions of the user's nose.

15. The method of claim 1, wherein the custom fitted mask comprises a mask for use in treating sleep disordered breathing.

16. A method of forming a custom fitted mask, comprising:
accessing a mask blank comprising a thin sheet of deformable thermoplastic polymer material that is already contoured in the shape of a portion of a generic user's face surrounding the generic user's nostrils, the portion of the generic user's face comprising only soft cartilaginous portions of the generic user's nose and portions of the generic user's face on either side of and below the soft cartilaginous portions of the generic user's nose and excluding hard bony portions of the generic user's nose generally above the soft cartilaginous portions of the generic user's nose; 
inserting into holes of the mask blank, one for each of a user's nostrils, fittings for coupling the custom fitted mask to an external gas supply system; 
heating the mask blank to transition the mask blank from a non-deformable state into a deformable state; 
while the mask blank is in the deformable state, applying the mask blank against a portion of the user's face surrounding the user's nostrils, the portion of the user's face comprising only soft cartilaginous portions of the user's nose and portions of the user's face on either side of and below the soft cartilaginous portions of the user's nose and excluding hard bony portions of the user's nose generally above the soft cartilaginous portions of the user's nose; 
deforming the mask blank against the portion of the user's face to cause the mask blank to conform substantially optimally to the user's unique bone structure and facial features, the mask blank once conformed substantially optimally to the user's unique bone structure and facial features comprising the custom fitted mask; and 
allowing the custom fitted mask to transition from the deformable state into the non-deformable state for use in treating sleep disordered breathing, the custom fitted mask when in use is adapted to cover a portion of the user's face surrounding the user's nostrils, the portion of the user's face comprising only soft cartilaginous portions of the user's nose and portions of the user's face on either side of and below the soft cartilaginous portions of the user's nose and excluding hard bony portions of the user's nose generally above the soft cartilaginous portions of the user's nose.