US 3113568 A
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Description (OCR text may contain errors)
Dec. 10, 1963 J. 5. ROBINS 3,113,568
STYPTIC BANDAGE 2 Sheets-Sheet '1 7 Filed Dec. 26, 1961 INVENTOR.
John S. Robins BY WHJIKEHEAD, VOGL a LOWE Pan 7M ATTORNEYS Dec. 10, 1963 J. s. ROBINS 3, 3,568
. STYPTIC BANDAGE Filed Dec. 26, 1961 2 Sheets-Sheet 2 IN V EN TOR.
John S. Robins BY WHITEHEAD', VOGL a LOWE ATTORNEYS 3,113,568 STYPTIQ BANDAGE John S. Robins, 600 Gaylord, Denver 6, Colo., assignor of one-half to Eric K. Erskine, Qhicago, Ill. Filed Dec. 26, 1961, Ser. No. 162,062 9 Claims. (Cl. 128-156) This invention relates to bandages and more particularly to bandages for open Wounds to cover and protect the same and especially to facilitate the stanching of bleeding; a primary object of the invention being to provide a novel and improved construction of a bandage which is especially adapted to initiate, engender and procure hemostasis. As such, the invention will be hereinafter described and referred to as a styptic bandage although it is to be understood that the utility of the bandage is not restricted to this preferred use.
Except in the case of severe Wounds, as where arteries are severed, hemostasis will normally occur spontaneously by blood clotting although external agencies such as styptics may be used to facilitate such action. The easily observable phenomenon of blood clotting occurs through a complex interaction of fluid and discrete constitutents of the blood, which is as yet not fully understood. However, if a drop of freshly drawn blood is placed upon a slide and observed with a microscope, it will be found that delicate threads, or fibrils, are formed throughout the whole drop and a meshwork of these fibrils cntangles the red blood corpuscles and encloses the liquid part of the blood. With larger amounts of blood, as in a container, or in a Wound cavity, the whole amount becomes jellylike and clings to the walls of the container. Soon the jellylike mass begins to shrink and as the shrinkage continues, to press out of the mass a yellowish liquid component called the serum. Once a clot, formed in this manner, has dried and hardened over a wound, it is most effective in protecting and permitting healing of the wound.
The coagulating-producing fibrils consist of a protein known as fibrin which does not initally exist in the blood when flowing through the veins and arteries of an individual, but is a substance produced from the activity of an agent which comes into being on leaving the environment of the blood vessels. It is believed that the blood normally contains at least five ingredients con cerned in coagulation. Certain of these ingredients are found in the plasma and other ingredients in the platelets or thrombocytes. These platelets, normally corpuscular elements, appear to trigger the coagulation action by breaking up and releasing a substance called thromboplastin. They are generally regarded as spherical or oval bodies approximately 3 micrornillimeters in diameter. On leaving the blood vessels, they rapidly agglutinate, or clump, and break to pieces to initiate a slow chain reaction With the other ingredients and in normal blood, full coagulation will occur in about 2 /2 minutes.
Without detailed explanation, it is thus apparent that an action which breaks up the platelets, or more effectively does so in a controlled manner will hasten or control the clotting actions which stanch bleeding. For example, it is well known that contact of the blood with a rough surface such as a towel or piece of bandage will assist in this. Stanching the flow of blood is therefore an important function of an ordinary cloth or padded bandage.
To better appreciate the present invention, an improved styptic bandage, it is necessary to point out certain limitations of ordinary bandages when used for this purpose. In the first place, the blood tends to flow past the fibres of an ordinary bandage and into the bandage itself without any significant coagulation commencing until all, or at least a substantial part of the bandage is soaked with blood. Next, after coagulation occurs and a clot is formed the capacity of the bandage to soak up the serum is limited, especially when the bandage is previously soaked with blood, and often to the point where excess serum which cannot be effectively removed by soaking into the bandage may prevent a clot from completely closing a wound. Finally, after the clot is formed and set, it is also set in the bandage to the point where it is next to impossible to remove the bandage without tearing the clot from the wound to initiate more bleeding and exposing the open wound to contamination.
Such undesirable features in a bandage have been long recognized and heretofore efforts have been made to separate the bandage from the finally-formed clot as by using a thin plastic membrane between the wound and the absorptive padding of the bandage, with absorption being effected as with flaps or gates cut in the membrane. A membrane facilitates the removal of a bandage from a wound, but limits the absorptive power of the padding element. Moreover, by its very nature, a membrane sur face will not especially accelerate breaking up and agglutination of the platelet constituents of the blood. While the breaking up and agglutination of the platelets is accelerated by contact with foreign surfaces, the acceleration is roughly proportional to the area of the surface of contact and a rough absorptive material such as gauze presents a far greater effective contact surface than does a smooth non-absorptive membrane surface. Clot formation at the wound is impeded by a non-absorptive membrane surface.
The present invention was conceived and developed with the above factors in view and comprises, in essence, an improved construction of a styptic bandage which is formed by facing an absorptive pad with a closely-knit, reticulated barrier characterized by the property of permitting and facilitating the passage of liquid and serum components of blood therethrough and into the absorptive pad and, and the same time, causing agglutination of the platelets and the subsequent formation of fibrin at the face thereof.
It follows that a further object of the invention is to provide a novel and improved styptic bandage which is especially adapted to initiate clot formation at the contact surface of the bandage and to accelerate and control the formation of a clot over a bleeding cut or like wound.
A further object of the invention is to provide a novel and improved bandage having a reticulated barrier at the face of the bandage which facilitates the formation of a clot at this face and which further establishes a plane of weakness at the barrier to permit easy removal of the bandage from the clot without tearing the clot from the wound.
A further object of the invention is to provide in a bandage a novel and improved reticulated barrier at the face of the bandage which is conveniently and economlcal- 1y formed with an open-cell, plastic foam material.
Further objects of the invention are to provide a novel and improved bandage having a resilient, foam-like reticulated barrier at the face of the bandage which is soft to the touch, will not irritate open tissue, is non-toxic, and may be easily sterilized in any ordinary manner.
Further objects of the invention are to provide a novel and improved styptic-type bandage which is a low-cost, neat-appearing, versatile and reliable product.
With the foregoing and other objects in view, all of which more fully hereinafter appear, my invention comprises certain novel and improved constructions, combinations, and arrangements of parts and elements as hereinafter described, defined in the appended claims and illustrated in the accompanying drawing which- FIG. 1 is an isometric View of the upper side of a patch bandage constructed according to the principles of my invention.
FIG. 2 is an enlarged isometric view of the underside of the patch bandage illustrated at FIG. 1.
FIG. 3 is a transverse section as taken from the indicated line 3-3 at FIG. 1, but on a further enlarged scale.
FIG. 4 is a greatly enlarged fragmentary sectional portion of the bandage as taken from the indicated line 4-4 at FIG. 3.
FIG. 5 is a further enlarged view of a single cell of one component portion of the invention.
FIG. 6 is a transverse sectional view of a portion of the bandage, similar to FIG. 4, and diagrammatically illustrating the bandage as covering a fresh wound, with arrows indicating blood and plasma flow.
FIG. 7 is a diagrammatic view similar to FIG. 6 but showing the manner in which the bandage may be pulled away from a clot-filled wound and separated from the blood clot.
FIG. 8 is a fragmentary perspective sketch of the underside of another type of bandage, embodying the principles of my invention and with portions of under layers being removed to better illustrate the construction thereof.
Referring more particularly to the drawing, my invention may be embodied in a typical patch bandage 10, as illustrated at FIGS. 1 and 2, and it will be hereinafter described as such. The typical patch bandage 10 is characterized by an absorbent fiber pad 11 which is backed up by and located at the center of a holding strip 12,, the strip 12 having an adhesive surface 13 with the pad 11 being affixed to this surface. The bandage may be placed over a. minor cut or wound to cover the Wound with the pad covering the wound to permit the pad to absorb the blood flow therefrom and topermit the adhesive surface 13 of the strip 12 to adhere to the skin of the patient at each side of the pad and hold the bandage in place. Suitable holes 14 are cut in this back-up strip at the pad to provide for ventilation of the pad and to permit a drop'of liquid, such as an antiseptic, to be soaked into the pad after it is set, whenever this is desired. This bandage may be provided commercially in a closed sterile bag or container or the like, and it may include a removable protective waxpaper cover at its face; however, such features need not be considered herein since they are not concerned with the invention.
My invention contemplates the use of a firmly knit, reticulated foraminiferous barrier 2%) at the face of the pad 11 which is capable of facilitating coagulation of the blood by permitting certain constituents to pass through the barrier and retarding and inhibiting the passage of other constituents of the blood and especially engendering the formation of fibrin in the barrier 20.
It was discovered that this barrier could be formed of certain types of open-cell plastic foams which may be produced from resins such as polyurethane, polyether, and polyvinyl chloride and even from some type of elastomers, including natural rubber. However, it is to be recognized that where a plastic material capable of forming an opencell foam is selected to serve as a barrier 20, it must not "only have properties of being non-toxic and stable, it should also have a melting point of softening point which is sufliciently high to resist the temperatures encountered in an autoclave or like apparatus in which the bandage is apt to be placed for sterilization prior to packaging it.
Polyurethane foam was found to be especially suitable for this purpose and the invention will be described with respect to a barrier formed by this particular open-cell foam material, although it is to be understood that other materials, such as those above mentioned, can be used. "In the manufacture of polyurethane foam, the size of foam cells may be easily controlled and it is possible to obtain foam having a very small :cell structure. The cell form of this foam is generally constant, regardless of size, and when magnified as illustrated at FIG. 5, a single cell 21 appears to be in the general shape of a twelve or fourteen sided figure, of a type characteristic of the geometric form often assumed by a bubble in a mass of foamed substance. In this open-cell foam, each face 22 of the cell 21 is similar to an open, five or six-sided window frame with strands or minute bars of polyurethane forming leglike links 23 which are arranged in a five-sided pattern at each facial surface 22 of the cell. Polyurethane is a very tough and resilient material and the cells 21 may be of extremely minute portions Without impairing their strength or elasticity.
It is contemplated that the individual cells of the foam suitable for the purpose at hand will be in the range of one-half millimeter in diameter, or less. However, it is to be recognized that such is an average value, for the size of the cells will vary in a sheet of foam. With such material, the minute, rod-like interconnecting links form an extremely fine meshwork which is capable of providing ideal surfaces for initiating the formation of fibrin in the blood.
Such a foam material for the barrier 20 may be manufactured according to any conventional practice to provide a thin layer of material having a selected normal pore or cell size. A preferred method of manufacturing the barrier material is to provide blocks of foam which are then sliced into very thin layers or sheets. The thickness of each sheet is such as to provide a reticulated barrier and a preferred thickness of the barrier is approximately one millimeter or slightly less, which is with pores having a normal pore or cell size of one-half millimeter, sufiicient to encompass a thickness of approximately two layers of cells 21. This delicate, thin layer of material is translucent and almost transparent. Nevertheless, it forms a myriad of irregular passages which are interrupted by the irregular spacing of cell links 23 as in the manner illustrated somewhat diagrammatically at FIG. 4.
It is to be understood that while such dimensions may be preferred, other proportions of normal pore or cell size and thickness of the barrier may be used. Also, it is to be recognized that the reticulated barrier 20 may be manufactured according to other methods than those abovedescribed. For example, a very thin layer of liquid, foam forming resin may be spread upon a non-adhesive surface and then activated to the foamed form in a substantia-lly continuous operation.
'Inthe manufacture of a patch bandage 10 as illustrated, the polyurethane foam barrier 20 is generally shaped as a rectangular strip to fit over the pad 11 with the strip having substantially the same 'width as the pad, and having a length slightly exceeding that of the pad. Therefore, when placed over the pad 11, each end of the barrier 20 will overlap the pad slightly so that a narrow edge 24 at each side of the pad, can be afiixed to the adhesive surface 13 to effectively hold the barrier in place over the pad.
in the alternate form and especially where a larger bandage is used, such as the continuous bandage 10' illustrated at FIG. 8, it is desirable to laminate the barrier 20' to the pad 11' forming the bandage. This lamination maybe accomplished in several different methods. A very simple method is to merely cross-stitch or spot-stitch the barrier to the pad, as illustrated as 25 at FIG. 8. Rela=tively few stitches will be required for this purpose, for only a very light bond will be required between the barrier andpad to hold the barrier in place.
Another method of connecting the barrier to the pad is to use very small quantities of flexible adhesive, such as latex. For example, thinned latex may be lightly applied, as by a spray, to the contacting surfaces of both the pad '11 and the barrier .26, so that when they are pressed together enough adhesive action will occur to permit the thin, light-Weight barrier to adhere to the pad without impairing the porosity of either the barrier or the pad.
The use of such a bandage is diagrammatically illustrated at H68. 6 and 7 where a small patch bandage is placed over a fresh wound W to stanch the flow of blood B therefrom. The reticulated barrier 20, formed as a myriad of minute cell-shaping links 23, presents an ideal environment for the formation of fibrin, for each minute link of the individual cells will act as a focal point and base where the fibrin-producing substances will commence vto act. 'I'his accelerates the formation of a blood clot completely across the bandage. This five reticulated meshwork forms a barrier which will impede the passage of the agglutinating and solidifying components of blood through it, although it will not at all impede the flow of fluid components of the blood especially the serum. The result is, with normal blood, a material speeding up of the formation of a clot C covering the wound W and at the same time clot formation in the pad will be impaired because of a reduced amount of fibrin-producing substances passing the barrier. The clot C in the pad will be weak and sugared in structure. Blood plasma will then move through the barrier 20 and into the bandage pad ll as indicated by the arrows P.
The resilient barrier of polyurethane foam will thus form a plane of weakness through blood clot portion C and=C and permit the bandage to be easily removed from the wound and separated from the blood clot without tearing the clot out of the wound. This plane of weakness is especially well defined because the small links of polyurethane foam are in and of themselves non-absorbent to blood, and thus, while the cell structures of a myriad of links effectively act upon blood as heretofore described, the individual links when disturbed in a clot of blood easily pull free of the clot substance. All that is required is to gently stretch and distort the edges of the barrier about the edge of the clot as at 26 in FIG. 7. This action will pull and stretch the individual cells or pores in the foam and reduce the normal transverse size of such pores so as to break loose fragments of the clotted blood within the pores. This stretching of the resilient barrier in different directions will quickly loosen the barrier to the point where the portion of the clot within the bandage is severed from the portion Within the wound. Such an action is illustrated diagrammatically at FIG. 7 where the bandage has been partially removed from the wound leaving a protective blood clot C in the wound and separating the clotted blood C in the bandage from that remaining on the wound. The surface of the clot appears to be smooth. However, upon close examination, it will be seen that it has a roughened characteristic appearance which corresponds with the surface formation of the barrier.
It is to be noted that styptic, clot-producing agents may be used in combination with this improved bandage, and small amounts of common substances used for this purpose, such as alum or salts of iron and the like, may be located in the bandage within the interstices of the barrier 20 or at the contact surface between the barrier 20 and the bandage pad 11.
It is to be further noted that the texture of a finely fonned open-cell resilient resin such as polyurethane is very soft to the touch and such materials as polyurethane are chemically inert with respect to tissue. Because of this, the bandage 10 may also be advantageously used for other purposes such as to cover and protect burns and similar wounds where bleeding is not an important factor.
From the foregoing description of my invention, others can devise alternate and equivalent constructions which are within the spirit and scope of my invention. Therefore, my protection is to be limited only by the proper scope of the appended claims.
1. In a bandage having an absorbent fibrous pad and adapted for use in covering a wound from which coagulatable material is passing, the improvement which comprises a thin reticulated foam layer superimposed on one face of said pad, said foam layer having a multiplicity of open pores therein, said foam layer being laterally stretchable to reorient and reduce the normal transverse size of the pores therein, said pores having a. normal size such that coagulatable material passing through said foam layer toward said pad can form Within said foam layer, continuous coagulated pieces substantially only of a size which are readily broken by lateral stretching of said foam layer whereby said foam layer provides a plane of weakness within a coagulated mass extending from a wound into said pad.
2. The improvement defined in claim 1 wherein said foam layer comprises a sheet of resilient synthetic resin foam of the open pore type, wherein the thickness of the foam is approximately one millimeter, and wherein the average pore diameter is approximately one/half millimeter.
3. The improvement defined in claim 1 wherein said foam layer comprises a sheet of polyurethane foam.
4. The improvement defined in claim 1 wherein said foam layer comprises a sheet of polyether foam.
5. The improvement defined in claim 1 wherein said foam layer comprises a sheet of natural rubber latex.
6. The improvement defined in claim 1 and further including means for holding said foam layer against the face of the bandage.
7. The improvement defined in claim 1 wherein the bandage is formed as a patch bandage having an outer adhesive strip, wherein the absorbent pad is a rectangular patch disposed centrally of the strip, and wherein said foam layer has edges overlapping the pad and being affixed to the adhesive strip at opposite sides of the pad.
8. The improvement defined in claim 1 wherein said foam layer comprises a sheet of polyurethane foam, wherein the thickness of said sheet is approximately one millimeter, and wherein the pores in said sheet have diameters of less than the one/ half the thickness of the sheet.
9. A method of covering a wound to induce coagulation of blood passing therefrom and thereafter removing the covering, said method comprising the steps of:
(a) placing a thin flexible and stretchable reticulated foam layer pervious to at least some coagulatable layer;
(d) thereafter stretching said foarn layer laterally in different directions to break up continuity of coagulated blood material therein said layer; and,
(e) then removing said layer and said pad from the wound.
References Cited in the file of this patent UNITED STATES PATENTS 2,477,403 Brady July 26, 1949 2,858,830 Robins Nov. 4, 1958 2,888,013 Levitt May 26, 1959 2,972,350 Deker Feb. 21, 1961 2,992,644 Plantinga et a1. July 18, 1961