Abstract:
A parasitic Acari barrier fabric that impedes parasitic Acari movement, traps parasitic Acari, and/or exterminates parasitic Acari thereon or therein. The barrier fabric includes an outer face formed from open mesh construction having evenly spaced openings formed thereon that are adapted for passing parasitic Acari from outside the fabric to inside the fabric, an inner face that is breathable and configured for moisture vapor transmission from a wearer&#39;s skin therethrough but is impenetrable to parasitic Acari passed to the inside of the fabric, and an intermediate spacer that extends between and interconnects the inner face to the outer face to form the parasitic Acari barrier fabric.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 62/259,979 filed Nov. 25, 2015, the contents of which are incorporated by reference herein in the entirety. 
    
    
     TECHNICAL FIELD 
     This invention relates to an Acari barrier including fabrics, gaiters, and putees that are worn to kill, repel, and/or enervate parasitic Acari. The Acarine gaiter allows the wearer to safely participate in outdoor activities in areas where parasitic Acari are present. 
     BACKGROUND 
     There are a considerable number of devices and prior art for preventing human (and/or mammalian) contact with flying insects, but very few devices and/or prior art exists for preventing human and mammalian contact with Acari. For combating flying insects the prior art discloses various devices and strategies including: (1) block, (2) block and hold away, and (3) block and poison. 
     For example, U.S. Pat. No. 5,794,263 discloses methods and devices for simply blocking flying insects. Prior representative flying insect patents with a simple blocking strategy further include U.S. Pat. No. 5,717,990 and U.S. Pat. No. 5,119,510. These references disclose devices that utilize netting to block, for example, mosquito contact. However, a drawback of these inventions is that the flying insects, in particular mosquitoes may continue to sting through the netting. Thus, these inventions are at least partially ineffective. 
     A second strategy for combating flying insects is to block the flying insects while simultaneously holding the blocking mechanism away from the human body. This strategy solves the above mentioned problem of mosquitoes stinging through the netting. U.S. Pat. No. 5,600,850 is representative of this approach. A similar “block and hold away” strategy is disclosed in U.S. Patent Application No. 2006/0048291 and U.S. Pat. No. 7,243,375. It is notable that both U.S. Pat. No. 7,080,412 and U.S. Patent Application No. 2013/0232676 use spacer fabric(s) as the method to hold the blocking mechanism away from the body. Here, the spacer fabric serves as a breathable spacer layer that is effective in preventing mosquitoes from stinging through the net. 
     A third strategy for combating flying insects is “block and poison” as disclosed in U.S. Patent Application No. 2013/0291275 (Radefeldt). Similar to Radefeldt, yet exclusively targeting the  Ixodes  genus of Acari, is U.S. Pat. No. 6,141,802 (Drake). Drake teaches a tick barrier system for a pair of pants. The pants have an integral inner gaiter that fits snugly around the wearer&#39;s ankle and are stitched to the inside of the pant leg. The prevention strategy is to prevent Ixodae contact with the wearer&#39;s skin by creating a cavity where the Ixodae are frustrated in their attempt to find skin. Presumably the Ixodae never find the path up the outside of the pant leg and either drop off or are removed after careful post-wear inspection. Drake, similar to Radefeldt, has an impede-and-divert approach absent the poison aspect of Radefeldt. 
     There are many similar drawbacks to Radefeldt and Drake in combating Acari. The primary problem is that questing Ixodae, generally traverse from a height of 2 to 8 inches off the ground, and therefore will easily climb onto the exterior of the pant leg, avoiding altogether the impede-divert mechanism of the inner pant legs. The pant legs of Radefeldt and Drake will do little to stop questing Acari from climbing onto the respective garments. Furthermore, and again from the perspective of the present invention, these garments, aside from the fundamental flaw of providing a convenient way for Ixodae to climb on to the outside of the garment, and while they are designed to be durable, also fail in being easy to use, comfortable, attractive and inexpensive for the user simply looking to avoid parasitic Acari. 
     U.S. Pat. No. 6,353,939 (Arber), like Drake, addresses directly the avoidance of the parasitic  Ixodes  genus of Acari. Arber teaches a disposable onetime use legging made of paper with upper and lower elastic bands that hold the Ixodae-repelling covering in place on the wearer&#39;s leg, for preventing bites by causing Ixodae to climb across externally mounted adhesive strips which capture them. The prevention strategy is that Ixodae will (1) climb onto the host from the foot and (2) will be captured by adhesive strips, and (3) will be rendered harmless when the device is disposed. It is a one time use item. It is intended to be worn with shoes or boots and with the wearer&#39;s legs covered. Again, considered from the perspective of the current invention, the trap-and-discard approach of Arber, while possibly effective for trapping Ixodae, fails in being easy to use, comfortable, durable, attractive, and inexpensive. 
     Finally, U.S. Patent Application No. 2014/0283560 (Patton) discloses an ixodicidally treated-knit sleeve (i.e., a poison only approach) to be used as a leg or forearm covering. 
     While the above discussed prior art, discloses methods and devices of diverting and/or killing flying insects (and in some instances Acari), more effective devices and methods of impeding Acari movement and/or killing Acari are needed, SUMMARY 
     Disclosed is a parasitic Acari barrier fabric that provides a more effective approach for exposing Acari to greater amounts of acaricide as they traverse up the legs of wearers by impeding and diverting Acari movement with an impedimentary surface area of high wales and a diversionary field of deep pores attractive to exploration, backed by an impenetrable inner surface. The disclosed barrier fabric(s) and devices utilize an impede-divert-poison strategy that is far more effective than a poison only strategy. The disclosed fabrics and devices utilize this impede-divert-poison strategy with impedimentary wales and diversionary pores (openings) while concurrently providing comfort, durability, re-usability, and pleasing aesthetics that appeal to a wide range of users. 
     Specifically disclosed are parasitic Acari barrier fabric(s) adapted to impede parasitic Acari movement, trap parasitic Acari, and/or exterminate parasitic Acari thereon or therein. The fabric includes an outer face formed from open mesh construction having evenly spaced openings (pores) formed thereon that are adapted for passing parasitic Acari from outside the fabric to inside the fabric, each opening having a diameter ranging from 3 to 5 mm; an inner face spaced apart from the outer face, the inner face is breathable and configured for moisture vapor transmission from a wearer&#39;s skin therethrough but is impenetrable to parasitic Acari passed to the inside of the fabric; and an intermediate spacer that extends between and interconnects the inner face to the outer face to form the parasitic Acari barrier fabric. Each opening of the outer face, the inner face, and intermediate spacer forms individual compartments inside the fabric configured to impede parasitic Acari movement, trap and/or exterminate parasitic Acari therein. 
     In certain aspects, the evenly spaced openings of the outer face have a density ranging from 1 to 9 openings/cm 2 . 
     In certain aspects, the intermediate spacer has a length ranging from 0.5 mm to 3.0 mm in a direction extending from the inner face to the outer face. 
     In certain aspects, the intermediate spacer is formed of V needle stitch construction. 
     In certain aspects, each yarn in the intermediate spacer has an angle of intercept ranging from 45° to 85°. 
     In certain aspects, the inner face is formed of pillar inlay stitch construction. 
     In certain aspects, the inner face has a moisture vapor transmission rate ranging from 0.020 to 2.0 kPa s/m under ambient conditions. 
     In certain aspects, the fabric has an overall thickness ranging from about 0.5 to 10 mm in a relaxed state. 
     In certain aspects, at least one of the outer face, inner face, and intermediate spacer are treated with an acaricide, and in this aspect, the acaricide is microencapsulated. 
     In certain aspects, at least any two of the outer face, inner face, and intermediate spacer are treated with an acaricide, and in this aspect, the acaricide is microencapsulated. 
     In certain aspects, each of the outer face, inner face, and intermediate spacer are treated with an acaricide, and in this aspect, the acaricide is microencapsulated. 
     In certain aspects, the fabric further includes a tubular body configured for donning on a wearer&#39;s limb. 
     In certain aspects, the tubular body is a gaiter. 
     In certain aspects, the fabric is a puttee configured for wrapping around a wearer&#39;s limb or appendage. 
     Embodiments of the invention can include one or more or any combination of the above features and configurations. 
     Additional features, aspects and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein. It is to be understood that both the foregoing general description and the following detailed description present various embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages of the present invention are better understood when the following detailed description of the invention is read with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of the parasitic Acari barrier fabric; 
         FIG. 2  is a magnified cross-sectional view of the parasitic Acari barrier fabric; 
         FIG. 3  is a perspective view of a gaiter formed from the Acari barrier fabric; 
         FIG. 4  is a perspective view of an alternative gaiter formed from the Acari barrier fabric; 
         FIG. 5  is a puttee formed from the Acari barrier fabric; 
         FIG. 6  is a magnified cross-sectional view of the Acari barrier fabric pretreated with a microencapsulated acaricide with a suitable textile binder; 
         FIG. 7  depicts two separate data sets obtained when allowing pathogen free ticks to move freely on plain, 100% khaki pants or on an exemplary untreated gaiter for a three minute time period; and 
         FIG. 8  depicts Wilcoxon statistical analysis obtained from the two separate data sets in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which exemplary embodiments of the invention are shown. However, the invention may be embodied in many different forms and should not be construed as limited to the representative embodiments set forth herein. The exemplary embodiments are provided so that this disclosure will be both thorough and complete, and will fully convey the scope of the invention and enable one of ordinary skill in the art to make, use and practice the invention. Like reference numbers refer to like elements throughout the various drawings. 
     Referring now specifically to the drawings, a parasitic Acari barrier fabric  10 , is illustrated in  FIGS. 1 and 6 . In certain aspects, the barrier fabric  10  fabric may form a gaiter  100 ,  300  or a puttee  400  as shown in  FIGS. 3-5 . In certain aspects, the parasitic Acari barrier fabric  10  is treated with an acaricide which may be applied either during manufacture or post-manufacture by the user, which may kill and/or enervate the parasitic Acari. 
     While the acarine barrier fabric  10  can be formed in any desired width or length, the acarine barrier fabric  10  (and gaiter  100 ) shown in  FIGS. 1 and 3  is about 51 cm wide and 31 cm high and is formed into a conical frustum during manufacture. The parasitic Acari barrier fabric  10  includes two opposing faces  11 ,  12  and an intermediate spacer  13  that separates and interconnects the faces  11 ,  12 , as described in further detail below. The parasitic Acari barrier  10  can also be formed as a tubular body  300  or in a roll for use as a puttee  400  as shown in  FIGS. 4 and 5  respectively. 
     As shown in  FIG. 2 , the outer face  11  is knitted in an open mesh and includes pores  111  (openings) that allow for parasitic Acari entry and exploration in the fabric. The pores  111 , generally created by wale distortion in the knitting, combined with the spacial depth created by the spacer fabric  13  are attractive areas of exploration for the Acari, which slows Acari ascent while advantageously and concurrently exposing parasitic Acari to more of the applied acaricide. Similar to pores  111 , knitting underlaps and inclined overlaps of the wales  110  also provide physical impediments that further slow the instinctive upward climb of the parasitic Acari and further expose them to greater amounts of the acaricide. 
     While the spacer  13  provides breathability, its main function is to provide an attractive diversionary space to the target parasitic Acari so that they ingest more acaricide. 
     The inner face  12  of the fabric  10  is impenetrable to the parasitic Acari while concurrently providing the wearer with a smooth, nonabrasive surface, thus allowing for the disclosed fabric, gaiter, and/or puttee to be worn over bare skin if so desired. The inner face  12  is knitted such that it is impenetrable by these Acari, yet allows breathability. Breathability of the inner face  12  is particularly important for attracting Acari into the pores  111  and spacer area  13  with the body odor of the wearer. 
     The acarine barrier fabric  10  is formed using any suitable fabric forming technology such as weaving, various knitting techniques such as, for example, warp knitting and weft knitting, non-woven, stitching, or a combination of these techniques. The outer face  11 , the inner face  12 , and the intermediate spacer area  13  can be constructed using any suitable organic or inorganic monofilament or multifilament yarn such as polypropylene, polyester, polyethylene and nylon. Preferably, the structure should provide some stretch, whether mechanical or elastomeric, in the width-wise direction, and facilitate conforming the acarine barrier fabric  10 , gaiter  100 ,  300 , and/or puttee  400  around an appendage of the wearer. 
     The parasitic Acari barrier fabric  10 , gaiter  100 ,  300 , and/or puttee  400  shown in  FIGS. 1 and 3-5  can be treated during manufacture with finishes to provide additional Acari repellency or to improve the functionality or enhance the wrap wearing experience for the wearer. 
     More specifically, the preferred embodiment of the acarine barrier fabric  10  is constructed of monofilament or multifilament polyester yarns on a double needle bed warp raschel knitting machine. The acarine barrier fabric  10  is preferably constructed using an open-mesh knitting on outer face  11 , a pillar and inlay stitch on the inner face  12  and a 3 or 5 needle V in the spacer  13 . The parasitic Acari barrier fabric  10  weighs between 50-450 gm 2 , and more preferably between 200-300 gm 2 . The parasitic Acari barrier fabric  10  has a nominal thickness when not compressed or under tension of approximately 1.0-4.0 mm. 
     Referring to  FIG. 2 , a magnified cross-sectional view of the parasitic Acari barrier fabric  10  is shown. Shown in approximate proportion to the Acari barrier fabric  10  is an exemplary parasitic Acari (e.g., an adult, female  Ixodes scapularis )  20 . 
     The elements shown of the outer face  11  are wale height  110 , pore  111  (including pore diameter (or opening diameter)  112 ), and pore density  113 . The elements shown of the spacer  13  are spacer height  131 , airflow  132  as measured by air resistance, spacer yarn arrangement  133  as measured by the angle θ, and spacer yarn diameter  134 . The inner face  12  is also shown. 
     The object of the parasitic Acari barrier fabric  10  is to divert and impede Acari so that their exposure time to the applied acaricides is maximized. Acari, when exploring a mammalian body, are attracted to mammalian CO 2 , body odor and body warmth. The three variables of the outer layer  11  (wale height  110 , pore diameter  112 , and pore density  113 ), the four variables of the spacer layer  13  (spacer height  131 , airflow  132 , spacer yarn arrangement  133  and spacer yarn diameter  134 ) in conjunction with the qualities of the inner layer  11  form an effective diversionary and impedimentary apparatus, which attracts, impedes, and kills parasitic Acari. 
     Wale height  110  is a function of outer layer yarn diameter, desired pore diameter  112  and desired pore density  113 . There is no reason not to maximize wale height  110  since wale height serves to lengthen the distance the parasitic Acari must travel across the acaricidally-treated fabric. Yet wale height  110  is both determined, as well as limited by, the desired pore diameter  112  and pore density  113 . Wale height  110  will vary depending on the target parasitic Acari from 0.10 mm to 15 mm, and in the preferred embodiment between 0.5 and 2.0 mm. 
     Pore diameter  112  is determined by the size of the target Acari. In general pore diameter  112  is between 50% and 500% of the target Acari body diameter. Since there is great variation in the size of target parasitic Acari-0.19 mm (larvae of  Trombicula alfreddugesi ) to 3.0 mm (adult  Dermacentor variabilis )-pore diameter  112  may vary from 0.10 mm to 15 mm. In the preferred embodiment pore diameter  112  is between and 3 mm and 5 mm. 
     Pore density  113  is the number of pores in fixed area, generally a square centimeter. While parasitic Acari barriers generally have pores of equal size, parasitic Acari barriers with pores of different sizes are possible and anticipated here. In the preferred embodiment, where pore diameter  112  is equal across the fabric and between 3 mm and 5 mm, pore (opening) density  113  is between 1 and 9 pores (openings) per cm 2 . 
     Spacer height  131  of the parasitic Acari barrier is sized in proportion to the target Acari body height, ranging from 0.1 mm (larvae of  Trombicula alfreddugesi ) to 1.5 mm (adult  Dermacentor variabilis ). In a preferred embodiment, spacer height is between 0.5 mm and 3 mm. 
     Airflow  132  through the spacer layer  13 , inner layer  12  and outer layer  11  is important in both transferring and retaining body odor, CO 2  and body warmth (moisture vapor transmission), which attract the parasitic Acari to the pores of the acaricidally-treated fabric. In the preferred embodiment airflow  132  as measured by fabric air resistance is between 0.020 and 2.0 kPa s/m at ambient conditions. 
     Spacer yarn arrangement  133  affects the perceived attractiveness of the spacer layer  13  to the target acarines. In the preferred embodiment spacer yarn arrangement  133 , as measured by the angle θ, is between 45° and 85°. 
     Spacer yarn diameter  134  affects both the perceived attractiveness of the spacer layer  13  to the target Acari as well as airflow. In the preferred embodiment spacer yarn diameter will range from 0.03 mm to 0.25 mm for monofilament and between 0.3 mm and 0.85 mm for multifilament yarns. 
     Referring now to  FIG. 4 , a circular knit acarine gaiter  300  (tubular body or tubular sleeve) is shown, with the same preferred constructions described of the fabric (i.e., outer face, inner face, and intermediate spacer positioned there between) disclosed above. The acarine gaiter  300  includes an outer face  31  of an open mesh construction, an inner face  32  of tight weave and a spacer area  33  that both separates and interconnects the two faces  31 ,  32 , as shown in  FIG. 1 . Instead of being wrapped around the limb, the gaiter  30  is pulled onto (donned on) the limb. 
     Referring now to  FIG. 5 , an elongate knit acarine barrier fabric is shown in the form of a narrow fabric or puttee  400 , with the same preferred constructions described above. The puttee  400  includes an outer face of open mesh  41 , an inner face of tightly woven fabric  42  and a spacer area  43  that both separates and interconnects the two faces  41 ,  42 , as shown in  FIG. 1 . 
     Referring now to  FIG. 6 , in one preferred embodiment, any of the fibers of the inner face, outer face, and spacer may be treated with an acaricide. For example, in a preferred embodiment, all of the fibers  114  of the Acari barrier fabric  10 , gaiter  100 ,  300 , and/or puttee  400  are treated during manufacture with a microencapsulated acaricide  115  and a suitable textile binder. 
     In certain additional aspects, the fabric  10 , gaiter  100 , and/or puttee  400  may further include hook and loop fasteners that further aid in wrapping and fixing the fabric, gaiter, and/or puttee to a wearer. 
     Working Examples 
     The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, and methods described and claimed herein are made and evaluated, and are intended to be purely exemplary and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in ° C. or is at ambient temperature, and pressure is at or near atmospheric. 
     Test Description 
     Travel rates of nympal stage blacklegged ticks ( Ixodes scapularis ) were measured on (1) plain, 100% cotton khaki pants versus (2) an exemplary parasitic barrier fabric (referred to as “Lymeez 3D” in  FIGS. 7 and 8 ) and subsequently compared. Rates were measured as distance traveled/time. 
     Test Conditions 
     The below observations were conducted using laboratory-reared, pathogen free ticks (Lot 0216) held at 23° C. and 95% Room humidity (RH) under 14/10 conditions (i.e., 14 hours of light versus 10 hours of dark conditions per day). 
     During the test, subjects wore either (1) plain, 100% cotton khaki pants or (2) a gaiter made from the untreated parasitic barrier fabric (i.e., a barrier not treated with acaricide) placed over plain, 100% cotton khaki pants. Subjects&#39; legs were held at a constant angle of about 700 relative to the floor. The laboratory-reared, pathogen free ticks (Lot 0216) were subsequently placed at the bottom the plain, 100% khaki pants (25 ticks) and gaiter (25 ticks) and were allowed to move freely thereon for three minutes. The tick&#39;s finishing position was marked after 3 minutes, and a straight line measurement (mm) was obtained between each tick&#39;s starting and finishing positions on the plain, 100% cotton khaki pants and gaiter respectively. 
     Results 
       FIG. 7  provides distribution data of for tick movement placed on the plain, 100% khaki pants and the gaiter respectively after 3 minutes. (Values in the bar graph of  FIG. 7  correspond to millimeters traveled in 3 minutes.)  FIG. 8  further provides Wilcoxon statistical analysis of the data collected during the above mentioned test. Using the Wilcoxon statistical analysis, a p-value of 0.0188 for the two-sided test was obtained when comparing the medians of the two data sets. As further shown in  FIGS. 7 and 8 , the medians of the two data sets are statistically, significantly different. The gaiter used in the above described test impeded and/or slowed tick movement roughly three times greater than tick movement observed on the plain, 100% khaki pants (median of 7 versus 19.5). 
     The foregoing description provides embodiments of the invention by way of example only. It is envisioned that other embodiments may perform similar functions and/or achieve similar results. Any and all such equivalent embodiments and examples are within the scope of the present invention and are intended to be covered by the appended claims.