Patent Publication Number: US-6988500-B1

Title: Fog free medical face mask

Description:
RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Application No. 60/470,817, filed May 15, 2003. 

   FIELD OF THE INVENTION 
   The present invention relates in general to a face mask used during medical procedures or to prevent communicable diseases or illness, and particularly to a face mask for use in preventing the fogging of eyeglasses. 
   BACKGROUND OF THE INVENTION 
   In many medical or dental procedures, it is often desirable for the medical professional to wear a mask over the mouth and nose. Typically, face masks are made of a filter material that will filter contaminants that are atomized, form an aerosol, or that are contained in the air, as well as liquid particles or liquid splashes. Masks are particularly beneficial in a dental office where high speed drilling devices, such as those used in many dental procedures in the mouth, which often causes the spread of liquid and other particles from the mouth into and throughout the air. This is additionally exacerbated by the requirement for a dental professional to work relatively closely to the patient&#39;s mouth in most dental procedures. The use of a face mask protects both the patient and the medical professional in preventing cross contamination between the patient and the medical professional or care giver. 
   There have been many different types of medical face masks developed in an effort to better protect individuals from contracting illness and disease. One such mask is disclosed in U.S. Pat. No. 3,971,369 entitled “Folded Cup-Like Surgical Face Mask and Method of Forming the Same” issuing to Aspelin et al on Jul. 27, 1976. Therein disclosed is a cup shaped surgical mask formed from a filtration medium that has angularly disposed foldlines. Another filtering face mask is disclosed in U.S. Pat. No. 5,307,796 entitled “Methods of Forming Fibrous Filtration Face Masks” issuing to Kronzer et al on May 3, 1994. Therein disclosed is a cup shaped non-woven fibrous shaping layer for a filtering face mask that is shaped by heating the non-woven fibrous material. Another face mask is disclosed in U.S. Pat. No. 5,694,925 entitled “Face Mask With Enhanced Seal and Method” issuing to Reese et al on Dec. 9, 1997. Therein disclosed is a face mask providing a filter body that is formed of multiple layers of filtration material with a plurality of pleats. Tie straps attached to flaps extending from the filter body form a fluid seal between the periphery of the mask and the wearer&#39;s face. 
   While these face masks have all been helpful in providing a face mask for use in many medical procedures, they are often uncomfortable and relatively difficult to breathe through. Additionally, the restriction on the free flow of exhaled air often causes warm, moist air to flow upward towards the user&#39;s eyes. In many applications where a user is also wearing eyewear, a face shield, glasses, or goggles, the upwardly directed moisture laden exhaled air often results in condensation or fog to be formed on the cooler eyewear, face shield, glasses, or goggle surface, obscuring the user&#39;s view. This is especially problematic in the dental profession where eyewear, face shields, glasses, or goggles are often used, as well as other visual aides used for working closely within a patient&#39;s mouth during a dental procedure. Therefore, there is a need for an improved medical face mask that is comfortable to wear and results in easier breathing therethrough, including preventing fogging of the user&#39;s eyewear, face shield, glasses, or goggles. 
   SUMMARY OF THE INVENTION 
   The present invention is a face mask that has a mask material having an opening therein. A filter material is used to cover the opening. The filter material may have perforations facilitating transmission of air or exhaled gases and moisture, increasing breathability and preventing fogging of glasses worn by a user. The filter material has a flow resistance less than that of the mask material. In another embodiment, a shield is attached to a portion of the mask adjacent the filter material and is positioned to direct exhaled air downward. In another embodiment, a shield has an adhesive strip with a protective cover which may be removed, exposing the adhesive strip so as to adhere the shield to the mask. 
   It is an object of the present invention to provide a face mask that is more breathable. 
   It is another object of the present invention to provide a face mask that prevents fogging of a user&#39;s eyes or eyewear. 
   It is an advantage of the present invention that it is comfortable to wear and has a portion with a reduced resistance to the flow of air. 
   It is another advantage of the present invention that the flow of air is directed away form a user&#39;s eyes or eyewear. 
   It is a feature of the present invention that a portion of the face mask adjacent a user&#39;s mouth or nose has a reduced resistance to the flow of air relative to the remaining portion of the face mask. 
   It is another feature of the present invention that a shield extends over a portion of the face mask having a reduced resistance to the flow of air. 
   It is yet another feature of the present invention that a shield is selectively affixed to and removable from the face mask. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view schematically illustrating one embodiment of the invention. 
       FIG. 2  is an exploded view illustrating the embodiment shown in  FIG. 1 . 
       FIG. 3  is a side elevational view illustrating another embodiment of the present invention. 
       FIG. 4  is a front elevational view illustrating the embodiment shown in  FIG. 3 . 
       FIG. 5  is a side elevational view illustrating another embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  illustrates the fog free face mask  10 . The fog free face mask  10  comprises a mask body  12  and a filter material  16 . The mask body  12  may be made of any conventional mask material. Preferably, the mask material is of a woven nature that is readily disposable and inexpensive. The mask material may be made of a natural or synthetic fiber. The mask body  12  may have a plurality of ribs  13  formed therein to aid in maintaining the shape of the mask body  12 . Within the mask body  12 , an opening  14  is formed. The opening  14  is positioned lower on the mask body  12  so as to be near or adjacent the mouth or nose of a user. 
   Placed over the opening  14  is a filter material  16 . The filter material  16  may be glued in position, covering the opening  14 . The filter material may be perforated, but is capable of filtering liquids, particles, and aerosols of a size appropriate for the intended purpose of the fog free face mask  10 . The fog free face mask  10  may be fluid proofed with a solution that prevents any fluids from penetrating the mask body  12  and the filter material  16 . Any conventional fluid proofing material or solution may be used. Attached to the mask body  12  is an elastic strap  18 . Other means for holding the fog free mask  10  to the face of a user may be used, such as eyeglass type earpieces or ear loops. 
   The fog free face mask  10  of the present invention greatly reduces fog from developing on a user&#39;s eyeglasses or eyewear. The filter material  16  permits gases and moisture to more freely pass there through relative to the mask material of the mask body  12 . Accordingly, a reduced volume of exhaled air and moisture is directed upward towards the user&#39;s eyeglasses or eyewear. This reduces fog formation on the user&#39;s eyeglasses or eyewear, as well as increases breathability and comfort of the fog free mask  10 . The term eyewear is intended to mean any eyeglasses, face shields, glasses, goggles, or other device intended to enhance vision, maintain vision, protect or shield the eyes. 
     FIG. 2  is an exploded view of the embodiment of the present invention shown in  FIG. 1 . In  FIG. 2 , the sequence of assembly is clearly illustrated with the filter material  16  being positioned within the mask body  12 . The filter material  16  covers the opening  14 . The filter material  16  may be glued, sewn, or otherwise adhered to the circumference or periphery of the opening  14 . The filter material  16  may be ultrasonically welded to the mask body  12  material. 
     FIG. 3  illustrates another embodiment of the present invention incorporating a shield  120  to deflect exhaled air and gases downward, as well as to shield the filter material  116  from possible contamination. The mask body  112  may also have a plurality of ribs  113  to help maintain the shape of the mask body  112 . Within an opening  114 , the filter material  116  is placed. The filter material  116  has a lower resistance to the passage of air than the mask body  112 . An elastic strap  118  helps to hold the mask body  112  onto a user&#39;s face. On the mask body  112  is a point of attachment  122  for the shield  120 . The point of attachment  122  may be any flattened section sufficient to permit an edge of the shield  120  to adhere with an appropriate adhesive. The shield  120  may also be sonically welded to the mask body  112 . The shield  120  is positioned so as to direct exhaled gases and moisture downward. The shield may also act as a splash shield preventing fluids or other particles from directly contacting the filter material  116 . The shield  120  may be made of a plastic or other suitable material, such as a non-porous material. The shield  120  may also be made of the same woven material as the mask material. 
     FIG. 4  is a plan view illustrating the positioning of the shield  120 . The shield  120  is larger than the opening  114  in which the filter material  116  is placed. This assures that the entire filter material  116  is shielded. 
     FIG. 5  illustrates another embodiment of the present invention having an attachable shield  220 . The mask body  212  has an opening  214  with a filter material  216  placed therein. The mask body  212  also has a flat section  222 . The mask  212  may be held onto a user with the aid of the elastic strap  218 . In this embodiment, the attachable shield  220  has an adhesive strip  224  along one edge. Covering the adhesive strip  224  is a releasable protective cover  226 . The flat section  222  on the mask body  212  is adapted or configured to mate or match with the adhesive strip  224  upon removal of the releasable protective cover  226 . The shield  220  may then be readily attached to the flat section  222  on the mask body  212 . Therefore, the fog free face mask illustrated in  FIG. 5  may be utilized with or without the attachable shield  220 . Additionally, the fog free face mask illustrated in  FIG. 5  may be packaged in stacks, nested within each other, with the attachable shields  220  provided separately. This facilitates packaging and shipment. 
   Accordingly, the present invention has a filter material placed adjacent or near the mouth or nose of a user that permits gases and moisture that are exhaled to exit the face mask more freely than the material of the mask body. This greatly prevents the possibility of eyeglasses worn by a user to fog. Additionally, the face mask of the present invention has improved breathability and comfort.