Abstract:
An apparatus and system are disclosed to extract breathable air from snow via a protective helmet. The apparatus includes a protective structure, at least one air intake cavity, and a mouthpiece. The protective structure defines an inner cavity and an outer surface. A portion of a user&#39;s head may be placed within the inner cavity. The air intake cavity or cavities are disposed on the outer surface of the protective structure. The mouthpiece is in fluid communication with the air intake cavity or cavities. Additionally, the mouthpiece is configured to allow a user to draw intake air from ambient snow through the one or more intake cavities and to the user&#39;s mouth upon inhalation. Advantageously, the apparatus and system provide a reliable mechanism for drawing air from ambient snow when a user, especially the user&#39;s face or head, is at least partially buried in the snow. Additionally, bulky and inefficient breathing tubes are minimized or eliminated.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application No. 60/502,734 entitled “Protective Helmet for Air Extraction from Snow” and filed on Sep. 12, 2003 for Scott A. Ogilvie, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     Embodiments of this invention relate to emergency breathing devices and more particularly relate to protective helmets for air extraction from snow.  
         [0004]     2. Description of the Related Art  
         [0005]     In a typical avalanche accident, the snow accelerates to full speed and the snow mass usually comes to an abrupt halt in the run out zone. The snow packs tightly around the victim and sets up like concrete the instant the moving snow comes to a rest. A buried victim typically finds himself tightly encased in the heavy snow pack. Rarely can a fully buried victim escape this snow encasement by his own efforts.  
         [0006]     In addition to being buried and immobilized, the victim&#39;s air supply is most often very limited. The victim may or may not have an air pocket in front of his face or surrounding his head. If the head is very near the surface or there is a hole from the head to the surface, the victim is very fortunate. More often than not, however, the facial air pocket is small or nonexistent. As the victim breathes within this small confined space, the oxygen is rapidly consumed and replaced by carbon dioxide. Within a short time, the lack of oxygen and/or the abundance of carbon dioxide may cause asphyxiation and/or suffocation.  
         [0007]     Air diffusion, in which air may diffuse through the snow, between the snow pack and the air pocket helps to increase the time of breathable atmosphere. In some cases, air may diffuse from the surface of the snow pack, through the snow, to an air pocket near the victim&#39;s face. There is one phenomenon, however, which greatly limits the beneficial air diffusion between the snow pack and air pocket. This phenomenon is known as ice masking. Ice masking occurs when a person exhales warm, moist air into the small air pocket surrounding one&#39;s face, where the moisture condenses on the snow surface within the air pocket. After repeated breaths, the layer of moisture builds or thickens, greatly reducing the snow porosity at this boundary due to this accumulation of moisture. Unfortunately, the air within the nearby snow pack may become unavailable to the victim due to this moist snow layer. As a result, the victim rapidly suffocates and, if the victim is not located, unburied, and resuscitated, if necessary, the victim will die. After suffocation, the body temperature drops and the thick moist snow surrounding the face refreezes into what is commonly known as an ice mask. The thickness of this ice mask is a good indication of the length of time the victim remained alive before eventually suffocating.  
         [0008]     Many devices have been contrived in an attempt to extend the breathing time of a fully buried avalanche victim. Some of these devices employ carbon dioxide absorbers to absorb and, thereby, reduce the amount of carbon dioxide that is exhaled and rebreathed. Unfortunately, these devices do not address the problems resulting from the limited air that may diffuse through the snow pack. Other devices employ oxygen tanks in order to provide additional oxygen to the victim in addition to or in place of the diffused air. However, these devices are both bulky and heavy and, therefore, inhibit the movement of the user in many of the recreational activities that draw the users to the mountains in the first place. Additionally, many of these devices employ one or more tubes that connect the mouthpiece to the oxygen tank, typically worn on the users chest or back. These tubes may easily be ripped away from the victim&#39;s mouth or the oxygen tank due to the forceful movements of the avalanching snow.  
         [0009]     Another device, the AVALUNG, which is currently marketed in the United States and elsewhere, also employs a tube to bring air to the victim&#39;s mouth. The tube is connected to a type of air pouch that allows air to be drawing in from the surrounding snow pack. Versions of this device are used in jackets or on straps that may be worn as the outermost layer of clothing. In other words, the air pouch may be worn in an exterior compartment of the jacket. Alternatively, the air pouch may be strapped onto the victim via a contraption having a waist strap and a shoulder strap.  
         [0010]     However, these pouches are typically located around the victim&#39;s stomach or chest area, requiring a long tube to transfer the inhaled air to the user&#39;s mouth. As described above, it maybe difficult or even impossible to retain the mouthpiece in the user&#39;s mouth as the user is tossed about by the avalanching snow. Additionally, an avalanche victim may be swept away by an avalanche before engaging the mouthpiece. This may occur especially where the victim does not see the avalanche begin and/or where the victim does not have an audible warning, for example, due to the noise of heavy equipment or recreational machinery. Additionally, the surface area of the air pouch is typically small and limited by the costs of producing the device and possibly in order to not restrict the user&#39;s movement. The device also limits the user&#39;s dress because the device must be worn on top of all clothing and apparel worn by the user. The functionality of the device is nullified if it is worn, for example, under a jacket or obstructed by a piece of equipment, such as a backpack.  
         [0011]     From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method for air extraction from snow that are not subject to the same disadvantages and inconveniences. Beneficially, such an apparatus, system, and method would limit the requirement for long tubes that are likely to be torn away from the victim&#39;s mouth. The apparatus, system, and method also would advantageously be incorporated into existing equipment and maximize the amount of surface area used to draw in air diffused through the snow pack.  
       SUMMARY OF THE INVENTION  
       [0012]     The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available breathing devices. Accordingly, the present invention has been developed to provide an apparatus and system to extract breathable air from snow that overcome many or all of the above-discussed shortcomings in the art.  
         [0013]     The apparatus, in one embodiment, is a helmet that includes a protective structure, at least one air intake cavity, and a mouthpiece. The protective structure defines an inner cavity and an outer surface. A portion of a user&#39;s head may be placed within the inner cavity. The air intake cavity or cavities are disposed on the outer surface of the protective structure. The mouthpiece is in fluid communication with the air intake cavity or cavities. Additionally, the mouthpiece is configured to allow a user to draw intake air from ambient snow through the one or more intake cavities and to the user&#39;s mouth upon inhalation.  
         [0014]     The helmet may be a partial helmet (e.g., an open face helmet) or a full helmet (e.g., a shielded helmet having a protective chin bar). The air intake cavities may be integrally formed within the outer surface of the protective structure, in one embodiment, or separately formed and placed over the protective structure, in another embodiment. Where multiple air intake cavities are provided, they may be connected to one another by one or more air transfer channels. Furthermore, the air intake cavities may be connected to the mouthpiece via one or more of the following: a primary intake cavity, a mouth strap, an intake chamber, a valve, a breathing chamber, and so forth.  
         [0015]     In other embodiments, the mouth strap may include the intake chamber, an intake valve, and the breathing chamber. The intake valve prevents exhaust air from passing from the mouthpiece to the at least one air intake cavity. Additionally, the mouth strap may include an exhaust valve and an exhaust chamber. The exhaust valve substantially prevents the user from inhaling exhaust air. The exhaust valve and exhaust chamber pass exhaust air from the mouthpiece and breathing chamber to an exhaust channel upon exhalation by the user. The exhaust channel, in one embodiment, directs the exhaust air away from the at least one intake cavity. For example, the exhaust channel may direct the exhaust air to an exhaust tube configured to extend away from the protective helmet.  
         [0016]     Where the mouth strap includes the intake chamber and the exhaust chamber, these chambers may be disposed on a single side or on opposite sides of the mouthpiece. By disposing the intake chamber and exhaust chambers on a single side of the mouthpiece, the mouth strap may be a partial mouth strap. Alternatively, the mouth strap may be a full mouth strap. In certain embodiments, the mouthpiece may be integrated into a fixed chin bar of the protective helmet. Alternatively, the mouthpiece may be disposed on a mouth strap that is adjustably connected to the protective structure and may be adjusted to move the mouthpiece away from the user&#39;s mouth. For example, the mouth strap may be attached to the helmet at one or two points and configured to be rotated upward or downward when the mouthpiece is not engaged by the user.  
         [0017]     In a further embodiment, the apparatus may include an air-permeable extraction assembly made up of the at least one air intake cavity and a protective membrane. Additionally, the air-permeable extraction assembly may include an air-permeable membrane interposed between the at least one air intake cavity and the protective membrane. In a further embodiment, the protective helmet may include only the air intake cavities and the air-permeable membrane.  
         [0018]     Various embodiments of an extraction apparatus are also presented to extract breathable air from snow. The extraction apparatus includes an air-permeable extraction assembly and a transfer guide. The air-permeable extraction assembly is attached to an equipment device worn by a user and includes at least one air intake cavity and an air-permeable membrane disposed thereon. The transfer guide directs extracted air from the at least one air intake cavity of the air-permeable extraction assembly to a protective helmet for extracting breathable air from snow. In one embodiment, the protective helmet includes an extraction apparatus attachment orifice to which the transfer guide may be connected.  
         [0019]     In further embodiment, the extraction apparatus may include a protective membrane disposed on the air-permeable membrane. Furthermore, the air-permeable extraction assembly may be attached to the equipment device using one or more snaps, clips, attachment straps, pockets, and so forth.  
         [0020]     Various embodiments of an air extraction backpack are also presented to extract breathable air from snow. The air extraction backpack includes a carrying strap, an air-permeable assembly, and an extraction assembly attachment device. The carrying strap allows a user to carry the air extraction backpack. The air-permeable extraction assembly includes at least one air intake cavity and an air-permeable membrane disposed thereon. The air-permeable extraction assembly is configured to allow a user to extract air from ambient snow upon inhalation by the user, as described above. The extraction assembly attachment device attaches the air-permeable extraction assembly to the air extraction backpack.  
         [0021]     In further embodiments, the air extraction backpack may include one or more transfer guides attached to the air-permeable extraction assembly and configured to pass intake air from the air-permeable extraction assembly to a mouthpiece upon inhalation by the user. The transfer guide may be at least partially embedded within a portion of the carrying strap. Additionally, the extraction assembly attachment device may be a releasable attachment device configured to allow the air-permeable extraction assembly to at least partially detach from the air extraction backpack.  
         [0022]     Advantageously, embodiments of the apparatus and system provide a reliable mechanism for drawing air from ambient snow when a user, especially the user&#39;s face or head, is at least partially buried in the snow. Additionally, bulky and inefficient breathing tubes are minimized or eliminated.  
         [0023]     Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.  
         [0024]     Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.  
         [0025]     These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]     In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:  
         [0027]      FIG. 1  is a schematic diagram illustrating a cut-away side view one embodiment of a protective helmet for air extraction from snow;  
         [0028]      FIG. 2  is a schematic diagram illustrating a sectional view of one embodiment of a portion of a protective helmet for air extraction from snow;  
         [0029]      FIG. 3  is a schematic diagram illustrating a cut-away view of one embodiment of a portion of a protective helmet for air extraction from snow;  
         [0030]      FIG. 4  is a schematic diagram illustrating a cut-away view of an alternate embodiment of a portion of a protective helmet for air extraction from snow;  
         [0031]      FIG. 5  is a schematic diagram illustrating a cut-away view of an alternate embodiment of a portion of a protective helmet for air extraction from snow;  
         [0032]      FIG. 6  is a schematic diagram illustrating one embodiment of a protective helmet system for air extraction from snow;  
         [0033]      FIG. 7  is a schematic diagram illustrating an alternate embodiment of a protective helmet system for air extraction from snow; and  
         [0034]      FIG. 8  is a schematic diagram illustrating one embodiment of an extraction apparatus for use with a protective helmet system for air extraction from snow.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.  
         [0036]     Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of materials, shapes, sizes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that embodiments of the invention can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.  
         [0037]      FIG. 1  depicts one embodiment of a user  102  wearing a protective helmet  104  for air extraction from snow. The protective helmet  104  is designed to be worn on the head of the user  102  in a manner similar to other protective headgear, such as full and partial helmets for skiing, snowmobiling, snowshoeing, and other winter sports in which the user  102  may be subject to potential snow burial. In one embodiment, the protective helmet  104  may be worn in place of any other protective headgear.  
         [0038]     The illustrated protective helmet  104  is secured to the user via a chin strap  106  that is conventionally employed in the art. The protective helmet  104  includes a plurality of air intake cavities  108  that are defined, in one embodiment, by a plurality of cavity dividers  109 , such as raised portions or walls. The air intake cavities  108  also may be joined together by one or more air transfer channels  110 . In a further embodiment, the air intake cavities  108  may be directly connected to a primary air intake channel  118 . The air intake cavities  108  are located on the exterior surface of the protective helmet  104  so that ambient air may enter into the air intake cavities  108  of the protective helmet  104 . In one embodiment, the air intake cavities  108  may be large so that few air intake cavities  108  are required over the surface of the protective helmet  104 . In an alternate embodiment, the air intake cavities  108  may be small in size and of various shapes, allowing hundreds or even thousands of air intake cavities  108  to be located on the protective helmet  104 .  
         [0039]     Although a specific size, number, and location of the air intake cavities  108  are illustrated in  FIG. 1 , the present invention may be embodied in a variety of designs and implementations. For example, the air intake cavities  108  may be located on a specific region of the protective helmet  104 , such as the crown, or may be located and separated into groupings of air intake cavities  108  and strategically placed on the protective helmet  104 . In one embodiment, the air intake cavities  108  may be located in groupings above and below a goggle strap band region (not shown) that forms an equatorial band around the protective helmet  104 .  
         [0040]     The illustrated protective helmet  104  also includes a mouth strap  114  that is located over the mouth of the user  102 . The mouth strap  114  may be formed with flexible, semi-rigid, or fully rigid material. For example, a ski helmet typically does not have a fully rigid chin bar and the mouth strap  114  may be made of semi-rigid material. In contrast, the mouth strap  114  may be incorporated into a fully rigid chin bar as in the case of a typical snowmobile helmet, for example. The mouth strap  114  is shown in an “engaged” position in which the user  102  is able to breathe through the protective helmet  104  in the event of burial by snow. In one embodiment, the mouth strap  114  may be adjustable for repositioning the mouth strap  114  away from the mouth of the user  102 , such as by rotating the mouth strap  114  down below the chin. In another embodiment, the mouth strap  114  may be configured to extend laterally in front of or to the side of the mouth of the user  102  in a “standby” position. In this way, the user  102  may breathe normally without using the breathing features of the protective helmet  104 . In a further embodiment, the mouth strap  114  may be in a fixed position. In another embodiment, the mouth strap  114  may be incorporated into a visor. In this way, the mouth strap  114  may serve as a visor while rotated up in the “standby” position and may be rotated downward into the “engaged” position as needed.  
         [0041]     In one embodiment, ambient air enters the air intake cavities  108  and passes through the transfer channels  110  as the user  102  inhales. The ambient air may be extracted from surrounding snow in the case where the protective helmet  104  and user  102 , for example, are buried in the snow. The user  102  may inhale the intake air, in the direction of the arrows  116 , from the air intake cavities  108  through a primary intake channel  118  via an intake orifice  120 .  
         [0042]     The mouth strap  114  may be configured to allow the user to breathe the inhaled air and subsequently exhale the air, in the direction of the arrow  122  into a primary exhaust channel  124  via an exhaust orifice  126 . The depicted protective helmet  104  further includes an exhaust tube  128  that is configured to attach to an opposite side of the primary exhaust channel  124  and direct the exhaled air away from the protective helmet  104  in the direction of the arrow  130 . By directing the exhaled air away from the protective helmet, the amount of previously breathed air, if any, that re-enters the air intake cavities  108  is minimized. To minimize or eliminate mixing exhaled air with inhaled air, the air intake cavities  108  located on the exterior of the helmet may be separated from the exit orifice (not shown) of the exhaust tube  128 . In one embodiment, this separation may include a minimum distance. Additionally, the separation may be improved by ensuring a barrier, such as the user, between the exit orifice of the exhaust tube  128  and the air intake cavities  108 .  
         [0043]     For example, in one embodiment, the exhaust tube  128  may direct the exhaled air to the region near the lower back of the user  102 . In an alternate embodiment, the exhaust tube  128  may direct the exhaled air to the region near the stomach of the user  102 . In a further embodiment, the exhaust tube may be incorporated into the mouth strap  114  or chin strap  106 , possibly not requiring a primary exhaust channel  124  or an exhaust orifice  126 . In these latter embodiments, the exhaled air may be transferred to the snow in front of the user  102  and still minimize the possibility of mixing the exhaled air with the air surrounding the top, sides, and back of the protective helmet  104 .  
         [0044]     The exhaust tube  128 , in one embodiment, also may be removable from the protective helmet  104 . In the case where an exhaust tube  128  is used, the exhaust tube  128  may be secured in place via a garment worn by the user  102 , such as a jacket or belt, or by attaching the tube in some fashion to a piece of equipment carried by the user  102 , such as a backpack.  
         [0045]      FIG. 2  depicts one embodiment of a cross-section  200  of the protective helmet  104 , including a protective structure  202  and a protective lining  204 . Although the protective helmet  104  is typically convex in shape to fit the head of the user  102 , the depicted protective helmet  104  is shown flat for clarity purposes. The protective structure  202  and protective lining  204  of the present invention are substantially similar to conventionally known protective structures, such as impact foam, and linings conventionally used in helmets. The protective lining  204  is typically located adjacent to the protective structure  202  on the interior of the protective helmet  104 . The head of the user  102  is typically placed in contact with the protective lining  204  during normal use of the protective helmet  104 .  
         [0046]     In the depicted embodiment, the protective helmet  104  also includes a plurality of air intake cavities  108  defined in part by a plurality of cavity dividers  109 . The air intake cavities  108  and cavity dividers  109  are generally located on the exterior of the protective structure  202 . In one embodiment, the cavity dividers  109  may be formed and located in a manner that provides additional structural protection to the user  102 . In an alternative embodiment, the structural integrity of the protective helmet  104  may be unaffected by the design and location of the cavity dividers  109 .  
         [0047]     The cavity dividers  109  illustrated are attached to or integrally formed as a part of the protective structure  202 . Alternately, the cavity dividers  109  may be a wholly separate component and may be placed in contact with the protective structure  202  under a force produced by the air-permeable membrane  210  and/or the protective membrane  212 . In other words, the cavity dividers  109  do not need to be integrated with or adhered to the protective structure  202 , but may be a separate structure held in place adjacent to the protective structure  202  by the air-permeable membrane  210  and/or the protective membrane  212 . In one embodiment, the air intake cavities  108 , cavity dividers  109 , air-permeable membrane  210 , and protective membrane  212  comprise an air-permeable extraction assembly  214 .  
         [0048]     The air-permeable membrane  210 , in one embodiment, is configured to allow ambient air to flow upon inhalation, in the direction of the arrows  216 , from the snow  218  (when the protective helmet  104  is buried) to the air intake cavities  108 . For example, air may be actively extracted from the surrounding snow through the inhalation efforts of a user  102  buried in snow due to an avalanche. In one embodiment, the air-permeable membrane  210  is impermeable to water, snow, and other similar elements, preventing penetration into the air intake cavities  108 . In an alternative embodiment, the air-permeable membrane  210  may allow water or other elements to enter the air intake cavities  108 . If water is allowed to enter the air intake cavities  108 , the protective helmet  104  may include drainage channels (not shown) that allow the water to exit the air intake cavities  108  prior to entering the mouth strap  114 . The air-permeable membrane  210  may be formed from a mesh material, in one embodiment. The protective membrane  212  is configured to protect the air-permeable membrane  210  from damage, such as tearing, due to impact and other use. The protective membrane  212  may include, in one embodiment, a hard impact plastic material that is designed to still allow air to enter the air intake cavities  108 . In another embodiment, the protective membrane  212  may be formed from a rip-resistant mesh material.  
         [0049]      FIG. 3  depicts one embodiment of a cut-away view  300  of the air-permeable extraction assembly  214 , including the air intake cavities  108 , cavity dividers  109 , air-permeable membrane  210 , and protective membrane  212 . Specifically,  FIG. 3  shows the air intake cavities  108  and cavity dividers  109  underneath the air-permeable membrane  210 , which is underneath the protective membrane  212 . In the illustrated embodiment, the cavity dividers  109  are located to define air intake cavities  108  in the form of a plurality of parallel and perpendicular channels. In this embodiment, the air-permeable extraction assembly  214  may not require air transfer channels  110  between the various air intake cavities  206 .  
         [0050]      FIG. 4  depicts a cut-away view  400  of an alternate embodiment of the air-permeable extraction assembly  214 . The illustrated embodiment is substantially similar to the embodiment depicted in  FIG. 3 , except that the cavity dividers  109  are of various shapes and sizes. The cavity dividers  109 , in one embodiment, may be placed according to a predetermined pattern, or may be placed at random with respect to one another.  
         [0051]      FIG. 5  depicts a cut-away view  500  of another embodiment of the air-permeable extraction assembly  214  having “honeycomb” cavity dividers  109 . In this embodiment, the cavity dividers  109  may form a plurality of air intake cavities  108  that are similar in shape to a honeycomb. Air transfer channels  110 , although not shown in  FIG. 5 , may connect the various air intake cavities  108 . In one embodiment, a transfer channel  110  may be formed within a cavity divider  109 . In an alternate embodiment, a transfer channel  110  may be formed between the outer surface of the protective structure  202  and the cavity dividers  109 . In a further embodiment, a transfer channel  110  may be formed within the protective structure  202 . In another embodiment, a transfer channel  110  may be formed within the air-permeable membrane  210 . Additionally, the cavity dividers  109  and the air intake cavities  108  may be reversed so that air transfer channels  110  are minimized or not required.  
         [0052]     The various embodiments of the air-permeable extraction assembly  214  depicted in  FIGS. 3, 4 , and  5  may be employed together or separately in helmets for one or more advantages. For example, a particular design for the cavity dividers  109  may increase the structural integrity of the protective structure  202 , thereby allowing the thickness of the protective structure  202  to be reduced. Another embodiment of the air-permeable extraction assembly  214  may provide an aesthetic appeal. Furthermore, a particular embodiment of the air-permeable extraction assembly  214  may maximize the surface area of the air intake cavities  108 , thereby maximizing the amount of helmet-to-snow surface area and accessibility to a maximum volume of extractable air.  
         [0053]      FIG. 6  depicts one embodiment of a full mouth strap  600 . The illustrated full mouth strap  600  includes an intake attachment  602  that is configured to be secured to the intake orifice  120  and an exhaust attachment  604  that is configured to be secured to the exhaust orifice  126 . The full mouth strap  600  also includes a mouthpiece  606  that is configured to fit into the mouth of the user  102 , one or more intake valves  608 , and one or more exhaust valves  610 . The intake valves  608  and exhaust valves  610  may be located within the mouth strap  600 , protective helmet  104 , at the intake orifice  120  and exhaust orifice  126 , respectively, or distributed throughout the protective helmet  104  and mouth strap  600 .  
         [0054]     With the mouthpiece  606  in place, the user  102  is able to inhale air through an intake chamber  612 , one or more intake valves  608 , and a breathing chamber  614 . Upon exhaling, the exhaust air exits through the breathing chamber  614 , one or more exhaust valves  610 , and an exhaust chamber  616 . The breathing chamber  614  is preferably designed to limit the amount of exhaled air that is rebreathed by the user  102 . For example, the breathing chamber  614  may be designed to hold only a small volume of air, forcing most of the exhaled air to exit through the exhaust chamber  616 . The exhaust air travels through the exhaust orifice  126 , primary exhaust channel  124 , and exhaust tubing  128 , as described above.  FIG. 6  also depicts the capability of adjusting the mouth strap  114  to a visor standby position  620  (shown dashed) in which the mouthpiece  114  may incorporate and serve as a visor when in the visor standby position  620 .  
         [0055]      FIG. 7  depicts one embodiment of a partial mouth strap  700  that does not cross the width of the face of the user  102 . Instead, the partial mouth strap  700  attaches to only one side of the protective helmet  104  at which both the intake orifice  120  and exhaust orifice  126  are located. The partial mouth strap  700  may comprise a single sheathing for both the intake air and exhaust air, or may comprise separate tubing for each of the intake air and exhaust air.  
         [0056]     The illustrated partial mouth strap  700  includes an intake attachment  702  at the intake orifice  120  and an exhaust attachment  704  at the exhaust orifice  126 . The partial mouth strap  700  also includes a mouthpiece  706  that is configured to fit into the mouth of the user  102 , one or more intake valves  708 , and one or more exhaust valves  710 . With the mouthpiece  706  in place, the user  102  is able to inhale air through an intake chamber  712 , one or more intake valves  708 , and a breathing chamber  714 . Upon exhaling, the exhaust air exits through the breathing chamber  714 , one or more exhaust valves  710 , and an exhaust chamber  716 . The exhaust air then travels through the exhaust orifice  126 , primary exhaust channel  124 , and exhaust tubing  128 , as described above. Both the full mouth strap  600  of  FIG. 6  and the partial mouth strap  700  of  FIG. 7  are configured to substantially prevent the user  102  from inhaling exhaust air through the exhaust system and exhaling exhaust air through the intake system, although some exhaust air may be rebreathed from the breathing chamber  614 ,  714 .  
         [0057]      FIG. 8  depicts multiple embodiments of an extraction apparatus for use with a protective helmet  104  as described above. Preferably, the extraction apparatus is similar in function to the air-permeable extraction assembly  214  of the protective helmet  104 . The illustrated embodiment includes a first extraction apparatus  802 , a second extraction apparatus  804 , and a third extraction apparatus  806 , each separately attached to a backpack  808 . Each extraction apparatus  802 ,  804 ,  806  is preferably constructed to include a plurality of air intake cavities  108  (not shown) and an air-permeable membrane  210  (not shown). A protective membrane  212  (not shown) may also protect the air intake cavities  108  and air-permeable membrane  210 . The air intake cavities  108 , air-permeable membrane  210 , and protective membrane  212  of the extraction apparatus are substantially similar to the air intake cavities  108 , air-permeable membrane  210 , and protective membrane  212  of the protective helmet  104  of  FIGS. 1 and 2 .  
         [0058]     The first extraction apparatus  802  also includes a first transfer guide  810  that is configured, in one embodiment, to direct air from the air intake cavities  108  of the first extraction apparatus  802  and the second extraction apparatus  804  to the protective helmet  104  via an extraction apparatus attachment orifice (not shown). The protective helmet  104  or first extraction apparatus  802  may further include a valve (not shown) that is designed to permit flow in a single direction, such as an intake valve within the transfer guide  810 .  
         [0059]     The second extraction apparatus  804  includes a second transfer guide  812  that, in one embodiment, may be connected to an extraction apparatus attachment orifice (not shown) on the first extraction apparatus  802 . In another embodiment of the invention, the second transfer guide  812  may interconnect with the first transfer guide  810  at a point between the air intake cavities  108  of the first extraction apparatus  802  and the protective helmet  104 . The illustrated third extraction apparatus  806  includes a third transfer guide  814  that is substantially similar to the first transfer guide  810  and is configured to direct air from the third extraction apparatus  806  to the protective helmet  104 , similar to the description above. The second transfer guide  812  and third transfer guide  814  also may include one or more valves (not shown) that permit air flow in a single direction only. The valves of the first, second, and third transfer guides  810 ,  812 ,  814  may be located within the transfer guides  810 ,  812 ,  814  near the helmet  104  or the backpack  808 . Alternately, the valves may be located within the extraction apparatuses  802 ,  804 ,  806  or within the protective helmet  102 .  
         [0060]     The first extraction apparatus  802  is configured, in one embodiment, to be attached to the backpack  808  via one or more adjustable straps  816 , such as an adjustable, nylon strap on the side of the backpack  808 . The second extraction apparatus  804  is configured, in one embodiment, to be attached to the backpack  808  using conventionally known clips  818 , including snaps, clips, and other similar attachments. The third extraction apparatus  806  is configured, in the depicted embodiment, to be attached to the backpack  808  via an exterior pocket  820  of the backpack  808 . The exterior pocket  820  is preferably manufactured of nylon mesh or another air-permeable material so that the third extraction apparatus  806  is maximally exposed to the snow when the backpack  808  and third extraction apparatus  806  are buried in the snow.  
         [0061]     The extraction apparatuses  802 ,  804 ,  806  shown are only exemplary embodiments that may be equivalent to the claimed present invention. Other embodiments may include different shapes and sizes and may be configured to attach to other types of equipment in addition to, or instead of, the backpack  808  shown. For example, a certain embodiment of the invention may include an extraction apparatus configured to be wrapped around the handle or blade of a shovel. In a further embodiment, the invention may include an extraction apparatus integrally attached within the outer lining of the backpack  808  such that the integrated extraction apparatus is contained within a pocket or window of the backpack  808 . In one embodiment, the integrated extraction apparatus may be sewn into the backpack  808  in a manner that allows the integrated extraction apparatus to maintain contact or access to the snow in the case of burial by snow. Similarly, the transfer guides  810 ,  812 ,  814  may be integrated or sewn into the backpack  808 , including the shoulder straps, for additional protection. Furthermore, the extraction apparatus, whether attached to the exterior of the backpack  808  or integrated within the backpack  808 , maybe made of rigid materials or flexible materials. In one embodiment, the extraction apparatus is made of semi-flexible materials that allow the extraction apparatus to bend and move with the exterior of the backpack  808 .  
         [0062]     A further embodiment may include an extraction apparatus configured to attach to the equipment at a single point or along a single seam, allowing the extraction apparatus to possibly extend away from the equipment in the case of an avalanche. For example, the second extraction apparatus  804  may be attached to the backpack  808  by a single clip  818 , allowing the unattached portion the second extraction apparatus  804  to possibly extend away from the backpack  808 . By extending away from the equipment, the extraction apparatus may have a greater surface-to-snow area permitting more air to be extracted from the surrounding snow. In a further embodiment, one of two attachment clips  818  may be a “break-away” clip that is configured to release upon impact, thereby allowing the second extraction apparatus  804  to extend away from the backpack  808 .  
         [0063]     Although the embodiments set forth in the description above discuss specific examples of implementing the features of the present invention in a protective helmet  104  and a backpack  808 , it should be appreciated that one or more extraction apparatuses may be incorporated in another medium other than the specific helmet  104  and backpack  808  presented above. For example, an extraction apparatus may be incorporated into an exterior garment that may be worn by a user. In one embodiment, the air extraction apparatus may be incorporated, such as sewn, into the garment. Alternately, the extraction apparatus may be attached to the exterior of the garment. Similar to the embodiments discussed with reference to  FIG. 8 , one or more transfer guides may be configured to transfer air from the extraction apparatus to an extraction apparatus attachment orifice of the protective helmet  104 .  
         [0064]     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.