Abstract:
An article of manufacture for protecting a wrist of a person as the person operates equipment over a work surface. The article of manufacture includes a sheet and multiple protrusions attached to and extending from the sheet. The sheet may be placed on the work surface and the protrusions are adapted to provide support of the wrist. Two edges of the sheet may include fasteners allowing the article of manufacture to be worn as a band on the wrist. The sheet and protrusions may be manufactured in a single manufacturing process.

Description:
FIELD AND BACKGROUND 
       [0001]    Carpal tunnel syndrome occurs when the median nerve, which runs from the forearm into the hand, becomes pressed or squeezed at the wrist. The median nerve controls sensations to the palm side of the thumb and fingers, as well as impulses to some small muscles in the hand that allow the fingers and thumb to move. The carpal tunnel, a narrow, rigid passageway of ligament and bones at the base of the hand houses the median nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the median nerve to be compressed. The result may be pain, weakness, or numbness in the hand and wrist, radiating up the arm. At the workplace, workers can do on-the-job conditioning, perform stretching exercises, take frequent rest breaks, wear splints to keep wrists straight, and use correct posture and wrist position. Wearing fingerless gloves can help keep hands warm and flexible. Workstations, tools and tool handles, and tasks can be redesigned to enable the worker&#39;s wrist to maintain a natural position during work. Employers can develop programs in ergonomics, the process of adapting workplace conditions and job demands to the capabilities of workers. 
         [0002]    Splints are safe and relatively inexpensive, and they give many people with carpal tunnel syndrome and other orthopedic problems short-term relief from their symptoms. Besides relieving discomfort, splints can sometimes improve conduction of nerve impulses along the median nerve, which can improve strength, dexterity and sensation. A number of designs for wrist supports are disclosed in U.S. Pat. No. 6,694,519 (Stewart) “Device and method for supporting the wrist and hand of a computer user”, U.S. Pat. No. 6,517,507 (Faherty) “Wrist guard for alleviating repetitive strain disorder by computer operators”, and US 2006/0226305 (Sheybani) “Wristband for keyboards and mouse use”. 
         [0003]    Rubber elasticity, also known as hyper elasticity, describes the mechanical behavior of many polymers, especially those with cross linking. Invoking the theory of rubber elasticity, one considers a polymer chain in a cross linked network as an entropic spring. When the chain is stretched, the entropy is reduced by a large margin because there are fewer conformations available. Therefore, there is a restoring force, which causes the polymer chain to return to its equilibrium or unstretched state, such as a high entropy random coil configuration, once the external force is removed. This is the reason why rubber bands return to their original state. 
         [0004]    Silicone rubber is a polymer that has a “backbone” of silicon-oxygen linkages, the same bond that is found in quartz, glass and sand. Normally, heat is required to set the silicone rubber. Silicone rubber articles are typically injection molded. 
       BRIEF SUMMARY 
       [0005]    According to the present invention there is provided an article of manufacture for protecting a wrist of a person as the person operates equipment over a work surface. The article of manufacture includes a sheet and multiple protrusions attached to and extending from the sheet. The sheet may be placed on the work surface and the protrusions are vertically oriented and adapted to provide support of the wrist. The sheet and protrusions may be manufactured in a single manufacturing process, e.g casting or injection molding. Alternatively, the sheet may and the protrusions may be of different materials typically with the sheet a stiffer material than that of the protrusions. The protrusions may have a lateral dimension, e.g. diameter of between 2 and 10 millimeters. The protrusions typically have a number density on the sheet between half and ten per square centimeter. In use, the protrusions provide support of the wrist. The sheet may include a woven textile matrix or a synthetic textile matrix. The protrusions may be made from an elastic material, such as by polymerizing an elastomeric resin. The protrusions may be made from selectably either silicone rubber, latex rubber or natural rubber or other elastomeric material. The sheet is optionally manufactured from a non-flexible material, an elastic material or a semi-rigid material. Two edges of the sheet may include fasteners allowing the article of manufacture to be worn as a band on the wrist. When the article is used as a mat on the work surface, the protrusions may be oriented upward toward the wrist or downward toward the work surface. Optionally, the height of the protrusions are graded along the length of the mat in order to provide the user with an adjustable height. Alternatively or in addition the height of the protrusions varies along the width of the mat in order to conform to the angle of the wrist to the work surface. 
         [0006]    According to the present invention there is provided an article of manufacture for protection a wrist of a person as the person operates equipment over a work surface. The article of manufacture includes a sheet with protrusions. The protrusions provide support of the wrist. The article of manufacture may function as either a mat for placement on the work surface or as a wristband both for the protection of the wrist. The sheet and protrusions may be manufactured in a single casting such as from a polymer resin which polymerizes into an elastic or resilient material. A wristband closure, e.g. buckle or snap is typically attached after the casting. 
         [0007]    According to the present invention there is provided a wristband of substantially elliptical cross-section in the plane of the wristband. The wristband functions to support a wrist of a person as the person operates equipment over a work surface. The wristband has multiple protrusions extending either inward or outward from the band. The sheet and protrusions may be manufactured as a single casting. The protrusions typically have a lateral dimension, e.g. diameter, of between two and ten millimeters and a number density on said sheet between half and ten per square centimeter. 
         [0008]    The foregoing and/or other aspects will become apparent from the following detailed description when considered in conjunction with the accompanying drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: 
           [0010]      FIGS. 1A and 1B  shows plan and cross sectional drawings respectively of an article of manufacture for protection of a wrist, according to an embodiment of the present invention; 
           [0011]      FIG. 1C  is a cross sectional view of the article of manufacture for protection of the wrist as a flat mat on a work surface, according to an embodiment of the present invention; 
           [0012]      FIG. 2  is illustrates the article of manufacture of  FIG. 1  being used as a wristband, according to an embodiment of the present invention; 
           [0013]      FIG. 3  is a diagram showing the article of manufacture being used as a flat mat placed on the work surface with protrusions facing upward, according to an embodiment of the present invention; 
           [0014]      FIG. 4  is an isometric drawing illustrating the article of manufacture as a wristband, according to an embodiment of the present invention; 
           [0015]      FIG. 5  is an isometric drawing illustrating the article of manufacture as a wristband, according to another embodiment of the present invention; 
           [0016]      FIG. 6  is an isometric drawing illustrating the article of manufacture as a wristband, according to yet another embodiment of the present invention; 
           [0017]      FIG. 7  is still another isometric drawing illustrating the article of manufacture as a wristband, according to another embodiment of the present invention; 
           [0018]      FIG. 8  is an isometric drawing illustrating the article of manufacture as a wristband, according to another embodiment of the present invention; 
           [0019]      FIGS. 9-11  illustrate different examples of lateral distribution of the protrusions which may be used in different embodiments of the present invention; 
           [0020]      FIG. 12  illustrates varying heights of protrusions, according to an embodiment of the present invention; 
           [0021]      FIG. 13  illustrates protrusions of two different heights and/or lateral dimension according to an embodiment of the present invention; and 
           [0022]      FIGS. 14-19  illustrate different examples cross sections of the protrusions, according to different embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings; wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. 
         [0024]    Referring now to the drawings,  FIGS. 1A and 1B  illustrate in plan (top view) and cross section of a single casting or other manufacture, e.g. injection molding of structure  7  of an elastic material, e.g. silicone rubber. Structure  7  to be used for protection of a wrist. The structure has protrusions  1  attached to a sheet  5 . Reference is now also made to  FIG. 1C  which illustrates sheet  5  is attached to a backing  3 . The material properties for the protrusions  1 , sheet  5  and backing  3  are selected according to the requirements of the utilization of structure  7 . 
         [0025]    Any casting method, e.g. injection molding, known in the art of polymer industrial processes may be used to form structure  7 . 
         [0026]    Reference is now made to  FIG. 2  which illustrates structure  7  in a preferred embodiment of the present invention being utilized as a wristband  16 . A hand  14  is shown using a computer mouse  12  on a work surface  10 . Backing  3  is preferably of canvas or similar textile material or another polymeric layer to provide comfort to the wearer of wristband  16 . 
         [0027]    Reference is now also made to  FIG. 3  which illustrates another preferred embodiment of the present invention in which structure  7  is utilized as a mat  18  with protrusions  1  facing upwards. Hand  14  is shown using mouse  12  on work surface  10 . Wrist/hand  14  is shown resting on protrusions  1 , in this situation the dimensions and undeformed shape of protrusions  1  are selected to provide comfort to the user of mat  18 . Optionally, a coating is applied to the top surfaces of protrusions  1  to provide additional comfort, i.e. the coating absorbs or dissipates sweat from the skin of the wrist. Backing  3  is optionally rubber to prevent the slipping of mat  18  or backing  3  is a canvas type of material which allows the movement of mat  18 . In other embodiments of the invention wristband  16  is closed with protrusions  1  facing inward toward the wrist instead of outward. 
         [0028]      FIGS. 4 and 5  show two different closure devices which form fasteners of wristband  16 , according to different embodiments of the present invention.  FIG. 4  shows the ends of wristband  16  being connected together by a clasp device, e.g. Velcro  20   a  and  20   b.    FIG. 5  shows the ends of wristband  16  being connected together by a press stud  22   a  and  22   b.    
         [0029]    Alternatively the ends of wristband  16  are connected together using any other method known in the art of fastening. 
         [0030]    Reference is now made to  FIGS. 6-8  which illustrates further embodiments of wristband  16 , according to different aspects of the present invention.  FIG. 6  illustrates an embodiment of wristband  16  in which sheet  5  and optionally backing  3  are semi-rigid so that hand  14  may be inserted into the wristband while elastically deforming sheet  5  and that after inserting hand  14 , wristband  16  elastically returns to its undeformed state and closes around the wrist. The term “lateral” as used herein in reference to wristband  16  refers to a direction which crosses the width of the band in a direction parallel to the axis of rotational symmetry of the band. wristband  16  of  FIG. 6  is cut substantially in the lateral direction so that while hand  14  is being inserted wristband  16  deforms elastically by opening the lateral cut. The term “radial” as used herein in reference to wristband  16  refers to a direction perpendicular to the axis of rotational symmetry of the wristband. The term “circumferential” as used herein in reference to wristband  16  refers to a direction perpendicular a radius of wristband  16  and tangential to wristband  16 . The terms “outward” and “inward” refer to directions substantially perpendicular to a tangent to the circumference of the wristband.  FIG. 7  illustrates an embodiment of wristband  16  in which sheet  5  and optionally backing  3  are typically more elastic (less rigid) than that of  FIG. 6 . Closure of wristband  16  is achieved by including in edge contours  24   a  and  24   b  significant circumferential portions. The circumferential portions of edge contours  24   a  and  24   b  allow a significant elastic distortion in the radial direction, i.e. opening the wristband, without having a large space in the band which would allow wristband  16  to fall sideways off the wrist. A similar effect is achieved if edge contours are straight but with a significant circumferential component.  FIG. 8  is an example of wristband  16  which is fully closed but is sufficiently elastic to allow deformation for inserting the hand through the band. In all embodiments, edge contours  24  are either cut from a subsequent to injection molding or are molded with the edge contours during the molding process. 
         [0031]    Reference is now made to  FIG. 9-11  which illustrate exemplary distributions in top view of protrusions  1  manufactured preferably in a single casting on sheet  5 , according to different aspects of the present invention.  FIG. 9  illustrates protrusions distributed in an ordered lattice of rows and columns. Although the lattice constants (distances between rows and columns) in both lateral directions are shown as equal, the present invention in other embodiments may be configured to have distances between rows different from the distances between columns. Similarly, lattice angles may be configured to be angles other than ninety degrees as shown the example of  FIG. 9 . Reference is now made to  FIGS. 10 and 11  which illustrate distributions of reduced order of protrusions  1  on sheet  5 . In  FIGS. 9 and 10  rows and columns are not necessarily straight but follow a predictable or random curve. The example of  FIG. 10  includes another aspect of borders which are not defined, order does not increase at the borders. Other features not explicitly illustrated may be used according to other features of the present invention. The cross sectional area of protrusions  1  may vary from row to row or column to column or even vary randomly throughout the distribution. Lattice angles may also be varied within the distribution. 
         [0032]    Reference is now made  FIGS. 12 and 13  which illustrate another aspect of the present invention. Specifically, in  FIG. 12 , heights of protrusions  1  vary monotonically along one or more lateral directions. The monotonic variation may be suited to the angle of the wrist and/or contour of the wrist while wristband  16  and/or mat  18  is in use.  FIG. 13  illustrates a periodic size (height and lateral dimension variation) along one or more lateral directions. A periodic height variation is preferably combined with another periodically varying parameter such as a periodically varying cross section of protrusion  1  along a lateral direction. 
         [0033]    Reference is now made to  FIGS. 14-19  which illustrate schematically in front view different example profiles of of protrusions  1 .  FIG. 14  illustrates a profile  1 A of a right angle prism or right circular cylinder with a flat top.  FIG. 15  illustrates a a profile of a right angle prism or right circular cylinder with a pointed top.  FIG. 15  illustrates a a profile  1 B of a right angle prism or right circular cylinder with a pointed top.  FIG. 15  illustrates a a profile  1 C of a right angle prism or right circular cylinder with a rounded top.  FIG. 16  illustrates a a profile  1 C of a right angle prism or right circular cylinder with a rounded top.  FIG. 17  illustrates a profile  1 D which includes a cone shaped bottom portion  1 E.  FIG. 18  illustrates a profile  1 F which in the bottom part is a right angled prism or cylinder  1 G and in the top part not right angled, for instance portions of cones, paraboloids or ellipsoids.  FIG. 19  illustrates a profile  1 I which is ellipsoid or paraboloid. 
         [0034]    The present invention in different embodiments may be realized using a number of elastomeric thermoset or thermoplastic polymers including:
       Unsaturated rubbers that can be cured by sulfur vulcanization such as Natural Rubber (NR), Synthetic Polyisobutylene (IR), Butyl rubber (copolymer of isobutylene and isoprene, IIR), Halogenated butyl rubbers (Chloro Butyl Rubber: CIIR; Bromo Butyl Rubber: BIIR), Polybutadiene (BR), Styrene-butadiene Rubber (copolymer of polystyrene and polybutadiene, SBR), Nitrile Rubber (copolymer of polybutadiene and acrylonitrile, NBR), also called Buna N rubbers, Hydrogenated Nitrile Rubbers (HNBR) Therban and Zetpol, Chloroprene Rubber (CR), polychloroprene, Neoprene, Baypren etc. Unsaturated rubbers can also be cured by non-sulfur vulcanization if desired.   Saturated Rubbers that cannot be cured by sulfur vulcanization include: EPM (ethylene propylene rubber, a copolymer of ethylene and propylene) and EPDM rubber (ethylene propylene diene rubber, a terpolymer of ethylene, propylene and a diene-component). Epichlorohydrin rubber (ECO), Polyacrylic rubber (ACM, ABR), Silicone rubber (SI, Q, VMQ), Fluorosilicone Rubber (FVMQ), Fluoroelastomers (FKM, and FEPM) Viton, Tecnoflon, Fluorel, Aflas and Dai-El, Perfluoroelastomers (FFKM) Tecnoflon PFR, Kalrez, Chemraz, Perlast, Polyether Block Amides (PEBA) Chlorosulfonated Polyethylene (CSM), (Hypalon), Ethylene-vinyl acetate (EVA); and p 1  Various other types of elastomers: Thermoplastic elastomers (TPE), for example Elastron, etc., Thermoplastic Vulcanizates (TPV), for example Santoprene TPV, Thermoplastic Polyurethane (TPU), Thermoplastic Olefins (TPO), and the proteins resilin and elastin and Polysulfide Rubber       
 
         [0037]    Preferred physical characteristics for the cast material are Shore A hardness in the range 10-70 
         [0038]    A casting was produced according to the embodiment of  FIG. 1  using a two component silicone elastomer S-471 (ESQUIM S.A., Barcelona, Spain) The inventor who suffers from carpal tunnel syndrome tested the prototype and found that the elastic protrusions alleviated discomfort. 
         [0039]    While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.