US 3561441 A
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Description (OCR text may contain errors)
nite States Patent Victor ,1. Lombardi 2715 Charlotte Lane, Burlington. NC
 Inventor  Patented  SURGICAL PRODUCT FOR DRESSING AND TREATING WOUNDS, AND METHOD OF MANUFACTURE 43 Claims, 10 Drawing Figs.
 U.S.Cl 128/156, 128/284, 66/194  lnt.C1 A611 15/00  Field of Search 128/155- 56] References Cited UNITED STATES PATENTS 2,764,976 10/1956 Skiles et a1 128/156 2,943,623 7/1960 Thompson... 128/155UX 3,040,551 6/1962 Urlaub 128/284UX 3,085,309 4/1963 Olson 128/284UX 3,113,570 12/1963 l-lolliday et a1 128/284 3,367,333 2/1968 Scheier 128/284 3,441,021 4/1969 Endres 128/ 156 FOREIGN PATENTS 744,572 2/1956 Great Britain 128/156 14 y \l 4 l4 Primary Examiner--L. W. Trapp Attorney (ushman, Darby & Cushman ABSTRACT: An improved surgical fabric for covering and treating wounds and promoting healing thereof is described. The fabric includes nonsticking loops, sheared or unsheared, on at least one face for contacting the wound and for spacing the remainder of the fabric away from the wound. The yarn loops may be synthetic and may include a polyfluorinated polyolefin in filament, spun or plastic ribbon form as a nonsticking material, or may-incorporate spun yarns of natural fibers suitably treated to impart nonstick characteristics. The nonsticking loops may be included as part of a knitted fabric construction. and additional, but shorter loops, sheared or unsheared, may be provided in the same fabric for wicking and/or absorbing liquids away from the region of the wound which is being treated. The improved surgical fabric may be produced on small circular knitting machines so as to produce a tubular, seamless fabric which can be placed around a limb or other body portion which is to be covered and treated. Stretch material may be incorporated in the tubular fabric to help prevent the accumulation of wound fluids and to assist in the retention of the dressing on a preferred placement over a wound. Although the fabric is described with reference to important surgical applications, it will be understood that the fabric is generally useful in applications requiring a transmittal and/or absorption of liquid from any surface area, as for example in diaper constructions or constructions for other articles of apparel.
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f PATENIEH FEB 9m y I 356L441 sum m4 'IMIM SURGICAL PRODUCT FOR DRESSING AND TREATING WOUNDS, AND METHOD OF MANUFACTURE BACKGROUND AND BRIEF SUMMARY OF THE INVENTION This invention relates to fabrics of loop construction, sheared or unsheared, for surgical applications, and more particularly, the invention is concerned with providing an improved surgical dressing or bandage, which includes nonsticking components for promoting drainage, ventilation, and healing of a wound relative to the main body of the fabric which is dressing and covering the wound.
In the treatment of wounds, certain significant factors must be considered in order to assure quick healing of a wound without danger of infection. These factors include provisions for proper drainage of the wound secretions, ventilation of the wound to prevent overheating, nonadhesion of the wound to a dressing which is covering it, and immobilization of the wound during the healing process.
Effective drainage hastens the drying of a wound and promotes faster healing and resistance to infection. It is known that this factor is especially important during the first few days of a healing process, when the danger of infection is greatest. Accordingly, it has been a practice to apply dressings to wounds for assisting in the absorption and removal of secretions from the wounds. Furthermore, clinical tests have demonstrated that compression of a wound by a highly absorbent material helps to prevent the accumulation of wound fluids, thereby accelerating the healing process while minimizing exposure to infection. However, the compression of a highly absorbent material on a wound may result in an adhesion of wound tissue to the dressing material, and this tends to retard the healing process because the new tissue or scab associated with the wound may be partially or completely torn off when such a dressing material is changed. As a result, there is a tendency to change dressings less frequently than would normally be desirable, and this practice can result in inadequate ventilation and overheating of a wound, thus increasing susceptibility to infection. It is also important that a wound be immobilized as much as possible to insure healing without disturbance by external pressures. Such pressures frequently arise from shrinkage of the bandage or dressing material which is covering the area of the wound, and this may result in pain and irritation of the wound and a prolonging of the healing process.
Various attempts have been made in the past to improve bandages, dressings and other surgical fabrics or products which can be utilized for covering and protecting a wound which is being treated and healed. Some prior art attempts have emphasized the importance of immobilization of a wound by maintaining shrinkable threads of a dressing out of contact with a wound. Such an arrangement is shown in US. Pat. No. 2,924,252, Feb. 9, I960. Also, a certain amount of breathing" or ventilation for a'wound has been attempted by adding a foam rubber layer to a bandage or dressing, as exemplified in patent 3,033,201, May 8, 1962. Also, it is known to include hydrophobic and hydrophilic fibers in a woven fabric which is intended to be used as a diaper as disclosed in 3,1 13,570, Dec. 10, 1963. However, the present invention is directed to a substantial improvement in a surgical fabric which may be used for dressing wounds and which considers all of the factors discussed above with respect to a quick healing of a wound without danger of infection.
The surgical product of this invention is constructed to satisfy the requirements of drainage, nonadhesion, ventilation and immobilization of a wound, as discussed above. These factors are satisfied by the provision of novel loop constructions, sheared or unsheared, for the fabrics of this invention, which may be produced on weaving, tufting, stitch or loop bonding, flocking, and on warp as well as weft knitting equipment. The surgical fabrics which will be described in detail below may comprise a single-face loop construction wherein loops appear on one side of the fabric only, or the fabrics may be of doubleface loop construction having loops on both sides of the fabric. It is also intended that the improved fabrics of this invention may be produced as open width or as tubular constructions. Furthermore, it is contemplated that the loop constructions of this invention may be sheared on an overall or a random basis to create pile effects in the fabric. In this regard, shearing will expose more of the filaments or fibers of the loop yarns thereby facilitating the wicking and/or absorbing of wound fluids and at the same time enhancing the nonsticking characteristics of the construction. In addition, whether in continuous loop form or in sheared form, the fabrics of this invention may incorporate in the loop yarns. fibers. slit plastic ribbons, or filaments of dissimilar shrink characteristics. This will permit, in desired instances, during the process of manufacture, the formation of loops of one level throughout the fabric construction, and then by the appropriate application of heat during the finishing process, the shrinkage of certain of the loops more than others, thereby creating the different levels in the finished fabric for the purposes herein described.
The products may be knitted on circular knitting machines of small diameter to produce seamless, tubular loop constructions which are especially suitable for use on leg and arm wounds. In addition, the tubular knit constructions can incorporate stretch yarn components, which may be in the'form of compressive bands located at opposite ends of the tubular dressing product. The spaced bands function to apply sufficient constrictive force to help prevent the accumulation of wound fluids, while at the same time obviating the need for adhesive tapes or other means for holding the surgical dressing in place. 1
The improved surgical product of this invention may be in the form of a fabric, whether knitted or not knitted, having a loop construction, sheared or unsheared, in at least one face of the fabric. The loop and/or pile construction may be single or multiple level, and the said multiple level may be created mechanically or by the use of loop yarns which shrink in differential amounts in the presence of heat. Furthermore, by the provision of a loop and/or pile construction, air pockets are incorporated in the structure and these assure adequate ventilation and drainage of a wound covered by' the surgical dressing of this invention. Further, the loop or pile construction of this invention includes a nonsticking characteristic for all loops or pile which normally contact the wound, and such a characteristic is achieved by fon'ning the wound contacting loops or pile from a material which may include a polyfluorinated polyolefin to impart nonsticking characteristics. It has been found that such loops may in some instances, be made with a monofilament yarn formed from a copolymer of tetrafluorethylene and hexafluoropropylene (FEP), with a multifilament yarn formed from a homopolymer of tetrafluorethylene (TFE), or with yarn spun with fibers of the above polymers. In addition, it has been found that such loops may be made with ribbons slit to appropriate widths from films produced with resins of the above polymers (sold under the Registered Trademark "Teflon"). It will be understood that spun yarns of natural fibers may be treated with resins of the polymers noted above to impart the nonsticking characteristic.
The invention also provides for multiple level loop constructions wherein longer loops are made with yarn or slit film in narrow ribbon form having a nonsticking characteristic, while lower level loops are made from a yarn which has wicking or absorbing characteristics. When the multilevel loop construction appears on one face only of the fabric, it is preferred that the longer loops be made from a ployfluorinated polyolefin yarn or slit ribbon and that the shorter loops be made from a highly absorbent yarn such as cotton. However, if this construction includes a so-called backing or ground yarn, then the longer loops can be made with the polyfluorinated polyolefin yarn, the shorter loops with a yarn exhibiting good wicking characteristics, and the ground yarn with a highly absorbent fiber such as cotton. On the other hand, when the dressingproduct is of the type having a double-face loop construction, it is preferred that a multilevel loop construction be provided on the wound contacting face while a single level, highly absorbent loop construction is provided on the opposite face of the dressing. The multilevel loop construction preferably includes long loops which have a nonsticking characteristic and shorter loops having a wicking characteristic for transmitting liquid to the highly absorbent loops on the opposite face of the dressing.
The invention further contemplates a construction in which differential loop levels are achieved by incorporating in the fabric loop yarns exhibiting shrinkage characteristics different from each other. For example, if a construction of single loop level is provided with a polyfluorinated polyolefin yarn or slit film such as Teflon at certain loops, and a shrink yarn such as polyvinyl chloride or polyvinylidene chloride (such as the polyvinyl chloride fiber sold under the Registered Trademark Rhovyl" by Societe Rhovyl) at certain other loops, and a cotton yarn for the backing or ground, and the construction subjected to suitable heat during the finishing process, the loops in which the polyvinyl chloride is present will contract thereby bringing their level below that at which the Teflon loops remain. Consequently, the Teflon" loops which contact the wound will prevent sticking of the dressing to the wound, whereas the shrink yarn such as Rhovyl," which also exhibits excellent wicking characteristics, will convey the wound secretions to the absorbent backing or ground cotton yarn. Furthermore, ribbons slit to an appropriate width from a polyolefin film such as heatshrinkablc polyethylene may be used to provide the shrinking characteristic previously noted.
It will be appreciated that if the previously described loop fabric is sheared on an overall basis as one of the steps of its manufacture prior to exposing it to suitable heat, differential shrinkage of the sheared loops will create a multiple level pile fabric. This pile construction will expose more ends of fiber at an upper level to provide gentler contact between the bandage and the wound, and more ends of fiber at a lower level away from the wound to provide increased capacity for accelerating the wicking of wound fluids to an outer absorbent fiber. Furthennore, it will be understood that if the so-called higher loops incorporate the shrink yarn, such as polyvinylidene chloride, the lower loops, the nonstick polyfluorinated polyolefin component, and the ground, the absorbent cotton yarn, and the fabric sheared to a level slightly above that of the polyfluorinated polyolefin loops, random sheared effects can be developed. By subjecting such a random sheared construction to suitable heat, the polyvinylidene chloride pile can be shrunk to a level below that of the unsheared polyfluorinated polyolefin loops.
The invention also provides for multiple-level loop constructions comprising yarns, described previously, in which the loops are positioned closer to the so-called ground fabric. This construction may take the form of a float configuration in which longer floats may contain the nonstick yarn, the shorter floats, the wicking yarn, and the ground fabric, the absorbent cotton yarn. This construction will result in a flatter, lighter weight surgical dressing uniquely suited for the treatment of less serious wounds.
As already mentioned, a knitted product may be formed on a small diameter circular knitting machine to provide a tubular, seamless dressing product having all of the desired loop constructions. The tubular dressing product has special utility for covering limbs of the body, and a stretch yarn component may be incorporated in such a product to provide for a compression of the tubular dressing around the wound area. In a preferred tubular dressing product, loop constructions will be provided only in the area of the dressing which is intended for covering a wound, and the remainder of the dressing may be fonned with no loops so as to decrease the weight of the dressing product. In this preferred construction, stretch bands may be provided at each end of the tubular dressing so as to compress the dressing at spaced regions adjacent to the wound area. In this manner, a wound may be easily covered and protected, and the dressing is maintained in its required position without the use of adhesive tape or other securing means.
BRIEF DESCRIPTION OF DRAWINGS FIG. I is a sectional clevational view of a surgical dressing fabric of this invention wherein the fabric is provided with a multilevel loop construction on a single face thereof;
FIG. 2 is a view similar to the view shown'in FIG. I, but showing a surgical dressing fabric having loop constructions on opposite faces of the fabric;
FIG. 3 schematically illustrates patterns of loop construction which may be utilized in surgical fabrics according to this invention;
FIG. 4 illustrates a further pattern of loop construction which may be used in a surgicalfabric;
FIG. 5 is a stitch diagram of a knitted fabric made in accordance with this invention and having the loop construction pattern shown in FIG. 3A;
FIG. 6 illustrates a tubular knitted fabric incorporating loop construction and other features of this invention;
FIG. 7 is a sectional, elevation view of a surgical dressing fabric of this invention wherein the fabric is provided with a single-level loop construction on a single face which has been sheared as one step in its manufacture;
FIG. 8 is a view similar to FIG. 7 illustrating the multiple levels of pile resulting from the differential shrinkage of the sheared loop yarns;
FIG. 9 is a perspective view illustrating a multiple level loop construction in which the loops are positioned closer to the ground fabric; and
FIG. 10 is a stitch diagram of a knitted fabric made in accordance with this invention and having the loop construction pattern shown in FIG. 9.
DETAILED DISCUSSION OF THE INVENTION Referring to FIG. I, a surgical fabric made in accordance with this invention and suitable for dressing a wound is indicated generally at 10. The fabric may be of a knitted or nonknitted construction, but an important feature of the invention is the provision of a loop construction on at least one face of the surgical fabric so that the main body of the fabric is spaced away from actual contact with a wound area 12. In the FIG. I embodiment, a multilevel loop construction is shown on a single face of the fabric, that face being the surface which normally contacts and covers a wound to be treated. The multilevel loop construction includes relatively long loops [4 which actually contact the wound area 12 together with shorter loops [6 which are disposed away from a tight contact with the wound area. The longer loops 14 function to space the main body of the fabric away from the wound area for a sufficient distance to provide good drainage and ventilation of the wound. As discussed above, it is important to provide for removal of wound secretions away from the wound area, and at the same time for ventilation of the wound to prevent overheating and susceptibility to infection. It is also a feature of this invention that the longer loops 14 function to prevent sticking or adhering of the surgical dressing to the wound itself. The long loops 14 are preferably made from a yarn or slit film in narrow ribbon form having a nonsticking characteristic, and such a yarn or ribbon may be made wholly or partially from a polyfluorinated polyolefin. The desired characteristic of nonsticking is included in yarns, fibers, or films made from polymers of tetrafluoroethylene (sold under the registered trademark Teflon), or polymers of trifluorochloroethylene (sold under the registered trademark Kel-F). The feature of nonsticking is extremely important for a rapid and safe healing of a wound, and this feature coupled with provisions for adequate drainage and ventilation results in a substantially improved surgical product for covering, treating and protecting wounds. By utilizing longer nonsticking loops 14 for actual contact with a wound area, there is provided a good immobilization of the wound despite any minor shrinking or other movement of the surgical dressing I0 relative to the wound. Since the contacting loops [4 are of a nonsticking characteristic, shrinking movements or other movements of the bandage or dressing will not irritate or abrade the wound or any tissue which is healing in the wound.
The shorter loops I6 of the FIG. 1 embodiment may be made of a yarn such as cotton or rayon yarns or fibers which is highly absorbent to liquids. The combination of a spacing layer of loops 14 with an absorbent layer of loops I6 provides for rapid drainage and ventilation of the wound area in a manner which promotes healing. In an alternative arrangement, the shorter loops 16 may be made from a yarn having good wicking characteristics, such as a yarn including a polyvinyl chloride or nylon. Inthe alternative arrangement, a ground yarn I8 may be provided in the fabric to absorb liquid which is wicked away from the wound area by the shorter loops I6. Of course, it is to be understood that the ground yarn 18 may be provided in a woven 'or nonwoven mat or fabric through which loops l4 and 16 are formed. On the other hand, the entire surgical dressing may be formed by knitting and the ground yarn 18 may be included in ground loops which combine the yarns of all of the loops. Furthermore, it will be understood that the surgical dressing of FIG. 1 may include a wicking yarn for the ground yarn 18. With this arrangement, a secondary covering material 19, exhibiting highly absorbent characteristics, may cooperate with the primary surgical dressing to absorb the wound fluids which wick through the primary dressing. Consequently, the primary dressing will remain relatively free from wound secretions and the secondary covering material 19 can be readily discarded as conditions dictate. Properly sterilized by autoclaving or otherwise, the primary dressing can be made reuseable.
FIG. 2 represents a second embodiment wherein a loop construction is provided on opposite faces of a surgical dressing product 10. As discussed for FIG. I, the wound contacting face may include a multilevel loop construction wherein longer loops l4 and shorter loops 16 are directed toward the wound area when the dressing is applied. The longer loops 14 have a nonsticking characteristic while the shorter loops 16 may have a wicking characteristic for carrying liquid away from the wound area. With the construction shown in FIG. 2, an increased absorption capacity can be provided by the loop construction 20 on a face of the dressing which is away from the wound area being covered. The loops 20 are preferably made from a yarn having a high absorption characteristic so that wound secretions which are wicked toward the outer surface of the surgical dressing 10 can be absorbed and retained by the dressing. It will be appreciated that the construction shown in FIG. 2 provides for a very substantial absorption surface, and yet, ample ventilation and drainage is provided in the region of the wound itself. Alternatively, the shorter loops I6 may also have a liquid absorbing characteristic, and in that case, a dressing is provided with a maximum absorption capacity.
As shown schematically in FIG. 3, the high and low loop configurations which have been discussed with reference to FIGS. 1 and 2 may be of any desirable pattern. For example, FIG. 3A illustrates a loop pattern wherein high and low loop areas and areas having no loops at all are arranged in horizontally disposed rows. FIG. 38 illustrates a vertically patterned configuration of high and low loops only. FIG. 3C illustrates a configuration wherein high and low loops are offset from one another in a more randomized pattern than that shown in B and C. Although the patterns of FIG. 3 are shown for only one surface of a surgical dressing, it will be understood that loop constructions and loop patterns may appear on a reverse side of the fabric as well. FIG. 4 illustrates a further pattern example wherein concentric bands of high loops l4 and low loops 16 are provided on a surface of the surgical fabric. Of course, any other pattern or configuration may be provided to accommodate specialized dressing applications and wound treatments.
FIG. 5 illustrates a stitch diagram of a knitted fabric which incorporates the loop construction features of the present invention. The stitch construction shown in FIG. 5 corresponds to the pattern layout schematically illustrated in FIG. 3A, and the numbered courses in FIG. 5 correspond to course numbers indicated in FIG. 3. The fabric of FIG. 5 includes high loops 14 in course 1, low loops 16 in course 3, and common ground loops 22. As discussed with reference to FIGS. 1 and 2, the high loops 14 are preferably made of a polytetrafluorethylcne yarn, in filament. fiber of slit film form so that these wound contacting loops will have a nonsticking characteristic. The lower loops 16 may be made of an absorbent yarn or a wicking yarn. The ground loops 22, similarly, may be made of an absorbent or a wicking yarn for the purposes previously described. The yarn used to form ground loops 22 is interknitted with the high loops 14 in course I, with the low loops 16 in course 3, and knitted alone in courses 2 and 4.
FIG. 6 illustrates a novel surgical dressing product in the form of a seamless tubular dressing which may be knitted on a small diameter circular knitting machine. A conventional knitting machine may be adapted to form the high and low loop configurations of this invention in the tubular article of FIG. 6, and the article may be formed with loops on one or both faces of the tubular product. When the multilevel loops are to be used on one face, such loops would normally appear on the inner surface 24 of the seamless tubular product illustrated. Additionally, loops may be provided on the outer surface 26 for absorbing liquid which is carried away from the wound area. The tubular article of FIG. 6 is especially useful for covering wounds on legs or arms, since it is only necessary to slide the tubular dressing over the limb which is being protected until the area of the wound is covered. It is also a feature of the FIG. 6 embodiment that a stretch component, or stretch yarn, may be included in the knitted structure of the tubular dressing. By giving the dressing a certain amount of stretch, a desirable compression of the wound area is provided for helping to prevent the accumulation of wound secretions. Although the stretch yarn or stretch component of the knitted article of FIG. 6 may be included throughout the knitted structure, it is preferred that stretch yarns be limited to bands 28 which are formed around the entire tubular structure and at spaced positions at opposite portions thereof. The bands 28 may be so spaced as to lie adjacent opposite ends of a wound which is being covered, and thus, the constrictive forces of the tubular dressing will be limited to the areas of the two bands 28. With this arrangement, the tubular dressing can be applied and held in place without a requirement for adhesive tape or other securing means.
FIG. 6 also illustrates a preferred knitted construction wherein the loop construction is limited to the region of the tubular article which is intended to cover the wound. This region is indicated generally at 30 in the construction shown for FIG. 6, and the remainder of the body 32 of the tubular dressing may comprise plain knitting so as to decrease the fabric weight in those portions of the bandage or dressing where additional bulk is not required.
FIG. 7 illustrates a construction of this invention in which the loops have been sheared to a single level, thereby exposing more of the end fibers or filaments. In this embodiment, there is shown the loop legs 14 which result when the nonsticking loops have been sheared, and the loop legs 16 which result when the wicking loops have been sheared. Through the shearing process, a more gentle contact between the wound 12 and the nonstick yarn I4 is achieved, and at the same time,
improved wicking of wound fluids to the absorbent ground 18 is made possible.
FIG. 8 represents a sheared fabric construction similar to that shown in FIG. 7. However, in this embodiment, the wicking yarn 16 also has the capability for shrinkage which can be developed in the presence of heat during finishing process. In this regard, a polyvinylidene chloride or polyvinyl chloride yarn such as Rhovyl may be used to provide the desired shrinkage and at the same time, the wicking required. It, accordingly, will be appreciated that differential loop or pile levels can be achieved in a'construction which is of uniform loop or pile height prior to exposure to heat. For example, if a fabric incorporating a polyvinyl chloride fiber, such as Rhovyl 55 is subjected to a heat ranging from l70 F. to 212 F., shrinkage of the polyvinyl chloride component will result, and at 212 F. the shrinkage will approach approximately 55 percent. Lesser shrinkage can be provided for by the use ofother polyvinyl chloride fibers.
FIG. 9 is a further embodiment of the invention illustrating a multiple-level loop construction comprising longer nonsticking loops or floats l4, shorter wicking loops or floats 16, and a ground fabric incorporating highly absorbent ground yarn 18. In this instance, however, both the nonsticking as well as the wicking loops are positioned closer to the ground fabric resulting in a flatter as well as a lighter surgical dressing. A dressing of this character can be effectively utilized for the less serious type of wound treatment. In addition to the use of long nonsticking loops 14 in combination with the shorter wicking loops [6 to create multiple'level loops, it will be understood that differential loop levels can also be created by the use of a fine count or light yarn for the wicking yarn, and a coarse count or heavier yarn for the nonsticking yarn. The heavier nonsticking yarn will contact the wound whereas the light wicking yarn will function to transmit the wound fluids to the outer absorbent ground fabric. Of course, the shorter loops 16 might include a fiber incorporating a shrinkage characteristic, alone or in combination with a wicking characteristic. as previously described. The use of a shorter loop 16, of FIG. 9, with a shrink characteristic will, upon the application of suitable heat to the fabric, cause the loop 16 to contract, thereby drawing the fabric in widthwise, and in so doing, forcing the loops l4 outwardly to create differential levels between the loops 16 and the loops 14.
FIG. 10 illustrates a knitted stitch diagram of the construction shown in FIG. 9. The construction is referred to in the art as single jersey having been produced on a knitting machine with a single set of needles. In the diagram, the ground fabric incorporates ground loops 23 made with a ground yarn l8, and the longer nonsticking loops 14 and the wicking loops 16 are introduced in the fabric as long and short lay-in loops respectively. It is to be understood that the long nonsticking loops and the shorter wicking loops can be positioned in any desirable configuration in the fabric. It will be further appreciatcd that the concept illustrated in FIG. 10 is equally applicable to fabrics of rib as well as other knitted constructions. When utilized in a fabric of rib construction, the surgical dressing may have the added advantage of not curling at its edges.
Similarly, the use of heavy nonsticking yarns at certain warp and filling positions of a woven fabric, and lighter wicking and/or absorbent yarns at certain other positions in the same fabric, will result in a flat lightweight woven construction exhibiting the nonsticking, wicking and/or absorbing characteristics desirable in a surgical dressing. In addition, a shrinkable fiber may be included in a woven fabric in the manner discussed for the knitted fabric of FIG. 9.
Having described the preferred embodiments of the present invention, it can be appreciated that there is provided a substantially improved surgical dressing having a novel combination of features which promotes healing of a wound. It is contemplated that many variations can be made in the invention, as described above, and the surgical dressing may be made in any sizes or shapes that may be desired. For example, the tubular construction which was described with reference to FIG. 6 may be conceivably knitted in relatively long lengths with multilevel loop construction throughout the interior surface of the long tubular length. Such long lengths could then be cut or otherwise divided up into suitable shorter sizes for adaptation to varying sizes of wounds. These and other variations and applications will become obvious to those skilled in the art, and all such variations and uses are intended to be included within the scope of the claims.
1. An improved surgical product suitable for dressing and treating wounds comprising:
a knitted fabric having loops included in at least one face thereof, said loops being included in the knitting of the fabric, and said loops having a nonsticking characteristic and being of a sufficient dimension to space the remainder of the fabric away from the wound so that there is adequate ventilation and drainage of the wound with substantially no sticking of the fabric to the wound.
2. The surgical product of claim 1 wherein said loops include a synthetic yarn having a nonsticking characteristic.
3. The surgical product of claim 2 wherein said synthetic yarn includes a copolymer of tetrafluoroethylene and hexafluoropropylene to impart nonsticking characteristics.
4. The surgical product of claim 1 wherein said loops include a film slit in narrow ribbon form and having a nonsticking characterisitc.
5. The surgical product of claim 4 wherein said film slit in narrow ribbon form includes a homopolymer of tetrafluoroethylene to impart nonsticking characteristics.
6. The surgical product of claim 1 wherein said loops in clude a yarn spun with natural fiber and treated for nonsticking characteristics.
7. The surgical product of claim 2 wherein said synthetic yarn includes a homopolymer of tetrafluoroethylene to impart nonsticking characteristics.
8. The surgical product of claim 4 wherein said film slit in narrow ribbon form includes a copolymer of tetrafluoroethylene and hexafluoropropylene to impart nonsticking characteristics.
9. The surgical product of claim 1 wherein said loops include a polyfluorinated polyolefin as a nonsticking material.
10. The surgical product of claim I and including additional loops in said fabric which are of a smaller loop dimension than said loops, whereby said additional loops are normally spaced out of tight contact with a wound when the surgical product is applied thereto.
11. The surgical product ofclaim 10 wherein said additional loops have a shrinking characteristic.
12. The surgical product of claim 11 wherein said additional loops include a polyvinyl chloride as a shrinking material.
13. The surgical product of claim 11 wherein said additional loops include a polyolefin film slit in narrow ribbon form as a shrinking material.
14. The surgical product of claim 1 wherein said fabric includes a stretch component in its construction.
15. The surgical product of claim 1 wherein said product is formed and used as a tubular knitted product having no seams.
16. An improved surgical product for dressing and treating wounds comprising:
a knitted fabric having multilevel loops formed in at least one face in the knitting thereof, said multilevel loops including longer loops formed from a yarn having a nonsticking characteristic and shorter loops formed from a yarn having a wicking or absorption characteristic, said said longer loops being of a sufficient size and number to space said shorter loops out of tight contact with a wound to be covered, whereby adequate ventilation and drainage of the wound is assured, and wherein substantially no sticking or abrading of the wound by the surgical product takes place.
17. An improved surgical product for dressing and treating wounds comprising:
a knitted fabric having multilevel loops formed in at least one face in the knitting thereof, said multilevel loops including longer loops formed from a film slit into narrow ribbons having a nonsticking characteristic and shorter loops formed from a yarn having a wicking or absorption characteristic, said longer loops being of a sufficient size and number to space said shorter loops out of tight contact with a wound to be covered, whereby adequate ventilation and drainage of the wound is assured, and wherein substantially no sticking or abrading of the wound by the surgical product takes place.
18. The surgical product of claim 16 wherein said multilevel loops are formed and extend substantially vertically of the ground fabric.
19. The surgical product of claim 16 wherein said multilevel loops extend substantially horizontally and are formed close to the ground fabric.
20. The surgical product of claim 19 wherein said multilevel loops are formed randomly in a knitted fabric.
21. The surgical product of claim 19 wherein said multilevel loops are formed as a lay-in in a knitted fabric at selected wale and course positions.
22. The surgical product of claim l6wherein said multilevel loops are formed with yarns of different size at each level.
23. The surgical product of claim 1 in combination with a separable secondary material for absorbing wound fluids.
24. The surgical product of claim 16 wherein said longer loops include a polyfluorinated polyoletin as a nonsticking material.
25. The surgical product of claim 16 wherein said shorter loops include a polyvinyl chloride as a wicking material.
26. The surgical product of claim 16 wherein loops are formed on two opposite faces of the fabric.
27. The surgical product of claim 16 wherein multilevel loops are formed on one face of said fabric and additional loops are formed on a second face of the fabric.
28. The surgical product of claim 27 wherein said multilevel loops on the one face include longer loops having a nonsticking characteristic and shorter loops having a wicking characteristic, and said additional loops on the second face of the fabric being formed from a yarn having an absorption characteristic, whereby liquid matter from the wound is carried through the fabric when said one face of the fabric is I placed on the wound.
29. The surgical product of claim 16 wherein said fabric is a knitted fabric.
30. The surgical product of claim 16 wherein said fabric and all loops formed therein are knitted on a circular knitting machine so as to produce a seamless, tubular product.
31. The surgical product of claim wherein said knitted product includes a stretch yarn in the fabric.
32. The surgical product of claim 30 wherein said knitted tubular product includes a band of stretch material in said fabric to fix the position of said tubular product around a limb or body portion having a wound which is to be dressed and treated.
33. The surgical product of claim 32 wherein two or more bands of stretch material are incorporated in said tubular product so as to provide compression of said surgical product on opposite sides of a wound being covered by the product.
34. The surgical product of claim 30 wherein said tubular knitted product includes an area of looped knitting in the portion of the product which is to cover a wound, and plain knitting in areas which are not intended to cover a wound.
35; An improved surgical product for dressing and treating wounds comprising a knitted fabric having loops formed in at least one face in the knitting thereof, said loops being sheared to form a pile, said sheared loops being located in at least a single level above the knitted fabric, certain of said sheared loops formed with a material having a nonsticking characteristic, and other of said sheared loops formed with a material having a wicking characteristic so that there is adequate vcntilation and drainage of the wound with substantially no sticking of the fabric to the wound.
36. The surgical product of 'claim 35 wherein the said sheared loops formed with a material having the wicking characteristic also have a shrinking characteristic so that when they are shrunk they contract to a level which is lower than the sheared loops having the nonsticking characteristic.
37. The surgical product of claim 36 wherein the said loops at a higher level are randomly sheared.
38. An improved surgical product suitable for dressing and treating wounds comprising a knitted ground fabric incorporating a yarn having a wicking or absorbing characteristic. and loops knitted integrally therewith, said loops exhibiting nonsticking and wicking characteristics.
39. The surgical product of claim 38 wherein the ground fabric incorporates a yam having an absorbing characteristic.
40. The surgical product of claim 38 in combination with a secondary material for absorbing wound fluids.
41. in a method for forming an improved surgical fabric having at least two levels of loops, with a higher level of loops having a nonsticking characteristic and with a lower level of loops having a wicking characteristic, the improvement comprising the steps of:
knitting a looped fabric from at least two different yarns, and utilizing a shrinkable yarn in the fabric as a yarn for forming loops having a wicking characteristic, and
treating the fabric to shrink the shrinkable yarn, thereby providing a fabric having wicking loops at a lower level than nonsticking loops.
42. The method of claim 41 wherein said shrinkable yam includes a polyvinyl chloride material, and wherein said treating step comprises a step of heating the fabric sufficiently to shrink the shrinkable yarn.
43. The method of claim 41 and including a step of shearing all loops of the fabric prior to treating the fabric, whereby a fabric having at least two levels of sheared loops will be formed.