Abstract:
A medical dressing for trauma injuries is disclosed. The dressing includes a base, a porous foam layer and a protective film. The base has a muffling side. The porous foam layer is partially attached on the muffling side. The protective film covers the muffling side and the porous foam layer.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The invention relates to externally-applied medical supplies, particularly to topical hemostatic tape for wounds. 
         [0003]    2. Related Art 
         [0004]    A medical dressing is an adjunct used by a person for application to a wound to promote healing and/or prevent further harm. A dressing is designed to be in direct contact with the wound, which makes it different from a bandage, which is primarily used to hold a dressing in place. Dressings are frequently used in first aid and nursing. It is generally used as a tool to stem the flow of traumatic bleeding. Usual dressings such as bandages, gauze and adhesive bandages possess water-absorbability, but they lack a hemostatic effect. 
         [0005]    Some medical dressings with a hemostatic effect such as thrombin or fibrin are provided, but their water-absorbability is not good enough to prevent absorbed blood from leaking. Additionally, such a dressing needs a bandage or adhesive tape for fixation. That is inconvenient for users. 
         [0006]    There is a tourniquet with a hemostatic layer in the market. Such a tourniquet is a constricting or compressing device, specifically a bandage, used to control venous and arterial circulation to an extremity for a period of time. Pressure is applied circumferentially upon the skin and underlying tissues of a limb; this pressure is transferred to the walls of vessels, causing them to become temporarily occluded. However, the tourniquet is available only for heavy bleeding or bleeding on four limbs. And application of the tourniquet will preclude blood from flowing and make the injured feel uncomfortable. 
       SUMMARY OF THE INVENTION 
       [0007]    An object of the invention is to provide a hemostatic dressing, which is simple to be applied and is provided with hemostatic effect. 
         [0008]    To accomplish the above object, the dressing includes a base, a porous foam layer and a protective film. The base has a muffling side. The porous foam layer is partially attached on the muffling side. The protective film covers the muffling side and the porous foam layer. 
     
    
     
       BRIEF DESCRIPTION OF THE INVENTION 
         [0009]      FIG. 1  is a sectional view of the first embodiment of the invention; 
           [0010]      FIG. 2  is a schematic view of the invention before water absorption; 
           [0011]      FIG. 3  is a schematic view of the invention after water absorption; 
           [0012]      FIG. 4  is a sectional view of the second embodiment of the invention; 
           [0013]      FIG. 5  is a schematic view of the third embodiment of the invention; 
           [0014]      FIG. 6  is a schematic view of the fourth embodiment of the invention; and 
           [0015]      FIG. 7  is a schematic view of the fifth embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]      FIG. 1  shows the first embodiment of the invention. As shown, the dressing  1  includes a base  11 , a porous foam layer  12  and a protective film  13 . The base  11  has a muffling side  111  for muffling a patient&#39;s skin. The porous foam layer  12  is partially attached on the muffling side  111  for absorbing water to generate pressure. The protective film  13  covers the muffling side  111  and the porous foam layer  12  for protecting the muffling side  111  from being stained and preventing the porous foam layer  12  from absorbing moisture before use. The protective film  13  may be release paper. 
         [0017]    Preferably, the muffling side of the base  11  is adhesive. The adhesion may come from the property of material or an adhesive coating on the muffling side  11 . 
         [0018]    The size of the dressing  1  is not limited. The base  11  can be selected from adhesive materials such as breathable tape and adhesive bandage or from non-adhesive materials with an adhesive coating. Alternatively, the base  11  can be disposed with a hook-and-loop fastener strip or other fasteners for connection. The material of the base  11  can be selected from nonwoven polyester fibers, polyurethane, cotton or silk. 
         [0019]    The porous foam layer  12  may be formed into different sizes and shapes for matching various wounds and may be made of hydrophilic polymers. To deal with a bleeding, the pressure generated due to absorbing water by the porous foam layer  12  should be ranged from 2 mmHg to 500 mmHg. For purpose of product classification, the pressure can be further configured between 200 mmHg and 500 mmHg and between 2 mmHg and 30 Hg. The porous foam layer  12  may be made of polyvinyl formal (PVF) obtained by formalization of polyvinyl alcohol (PVA). The above indicated polymer materials are compatible with skin such that interfacial adhesion problems can be avoided, and have excellent capability of water absorption such that expansion pressure can be generated and being proportional to the amount of water absorbed. 
         [0020]    Please refer to  FIG. 2 . The dressing  1  must be used on skin  2  before skin treatment. The protective film  13  has to be removed first. The muffling side  111  is attached on the skin  2  and the porous foam layer  12  must completely cloak the wound  21 . At this time, the porous foam layer  12  which attaches the wound  21  generates an action force  14  and the muffling side  111  which attaches the skin  2  generates an opposite reaction force  15 . As shown in  FIG. 3 , the porous foam layer  12  will expand after absorbing water and exert a stronger action force  14  against the wound  21  to obtain a hemostatic effect. And the reaction force  15  will become larger. The action force  14  depends upon the amount of water absorbed by the porous foam layer  12 . In other words, the more the water is absorbed, the larger the expansion pressure is generated. The total action force  14  is equal to the total reaction force  15 . The reaction force  15  will be borne by the skin  2  attached by the muffling side  111 . The pressure generated due to absorbing water by the porous foam layer  12  is exerted on the wound  21  only, but not on the circumferential areas of skin  2  around the wound  21 . Thus, the present invention avoids the problems of being overly constricted or compressed to wound  21  which may cause insufficient supply of blood to underlying tissue and resulting tissue damage as found in prior arts. Further, the present invention readily applies to various parts of human body, without being restricted to the limb area as occurred in prior arts. 
         [0021]    The first embodiment of the present invention provides a topical hemostatic tape  1  to be used in wound  21  of skin  2 , wherein its porous foamed layer  12  expands by absorbing water, thus establish suitable hemostatic effect by applying pressure to the wound  21 . And, the first embodiment of the present invention applies to various parts of skins of a patient, without being restricted to the limb area as occurred in prior arts, and thus is more convenient, comfortable and efficient, and safer than prior arts. 
         [0022]      FIG. 4  shows the second embodiment of the invention. As shown, the dressing  3  includes a base  31 , a porous foam layer  32  and a protective film  33 . The base  31  has a muffling side  311  for muffling a patient&#39;s skin. The porous foam layer  32  is partially attached on the muffling side  311  for absorbing water to generate pressure. The porous foam layer  32  is formed with a projection  321  toward the protective film  33 . The projection  321  can attach a wound more fitly. The protective film  33  covers the muffling side  311  and the porous foam layer  32  for protecting the muffling side  311  from being stained and preventing the porous foam layer  32  from absorbing moisture before use. 
         [0023]      FIGS. 5-7  depict various shapes of the projection  321 . The projection  321   a  shown in  FIG. 5  is of a linear shape. The projection  321   b  shown in  FIG. 6  is of a cross shape. The projection  321   c  shown in  FIG. 5  is of a spot shape. A skilled person in the art must know other shapes of the projection are also available. 
         [0024]    It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims.