Patent Application
20060085894
This invention relates to a medical compression garment having an integral donning aid. More particularly, this invention relates to compression stockings having a low friction zone made with the addition of or completely from low friction yarns or by coating/laminating of the inside surface of a garment with the low friction materials.
Therapeutic medical compression garments have been used on a relatively wide scale to assist in the prevention of venous diseases and/or embolism in a patient. The purpose of such garments is to overcome the elevated internal pressures within a human extremity caused by gravity or disease processes. The pressure gradient garments, such as stockings and their uses are well documented in the literature.
The custom pressure gradient stocking was developed by Conrad Jobst, a sufferer of venous disease. Mr. Jobst found relief from his problem while standing in a swimming pool. Mr. Jobst reasoned that the water pressure in the pool, which increases with depth, cancelled out the internal pressure in the veins of his leg. Jobst and others have identified a need to apply a relatively large compressive force in proximity to the ankle. See, J. Homer, et al., Br Med J, pp. zz: 820-821 (1980) wherein it is stated “the greater the compression gradient between the ankle and calf produced by the stocking, the lower the ambulatory pressures.” Cited in U.S. Pat. No. 5,823,195.
Therapeutic medical graduated compression stockings are designed to provide sufficient external circumferential counter pressure to maintain the normal venous and lymphatic pressures at a given level in the extremity, thus assisting the movement of venous blood and lymph from the extremity. Another important effect of compression is the reduction of the venous volume. Reduction of venous volume leads to an increase of the venous flow velocity. H. J. L. van Gerwen, Pressure gradient tolerance in compression hosiery. Katholike Universiteit Nijmegen, pp. 103-105 (1994).
For compression garments to be most effective, higher pressures are required in the ankle area. The most difficult part of putting compression garments (stockings) on is to pull the narrowest part of the garment over the wider end of a limb (foot-instep-heel for stockings or hand for arm-sleeves). There are special donning devices made from slick fabric that a patient should put on a leg before donning compression stocking. Use of these devices makes putting stocking on more complicated, sometimes requires help from another person and, also, requires purchase of such additional devices.
A variety of therapeutic medical graduated compression stockings are on the market today. Stockings of various descriptions have been proposed. Unfortunately, therapeutic stockings, in order to provide the necessary compression, are often thick and rather unsightly or have other drawbacks. An example of a therapeutic stocking is shown in U.S. Pat. No. 3,975,929 which describes a thigh length anti-embolism stocking made with alternating courses of covered spandex yarn on a circular hosiery knitting machine. Another example of a therapeutic stocking is described in U.S. Pat. No. 4,069,515 to Swallow, et al., which discloses a non-slip therapeutic stocking having a covered elastomeric yarn (spandex core-nylon covering) inlaid into every other course of the jersey knit stitches made of stretch nylon. In particular, the Swallow patent describes the foot portion as having alternating courses of jersey knit stitches of non-elastomeric yarn.
Because higher compressive forces are used in compression stocking U.S. Pat. No. 6,613,007 to Reid, Jr. discloses a multi-layer compression stocking. One of the problems of a multi-layer stocking is that it is difficult to coordinate the compressive pressures applied by each layer to achieve a desired pressure. Reid proposed to solve this problem by including in the layers alignment markings to assist a wearer in positioning the layers on the leg. There is disclosed a stocking comprising a plurality of layers including an under-layer and at least one over-layer, each of which have predetermined amounts of compressive stress at discrete locations. The under-layer may include yarns with high strength and low coefficient of friction properties incorporated into the fabric. Areas of the stocking including the toe, top of the instep and heel may be reinforced in such a manner to reduce the chance of skin breakdown and to reinforce the stocking fabric with yarns of high strength and low coefficient of friction properties. Several individual stockings are necessary to produce the multi-layered system which increases production costs and price to the customer. Also it is difficult to provide an exact match of the different zones especially for dark colored fabrics, avoid wrinkling and shifting of the underlying stocking, while pulling the upper stocking over it.
U.S. Pat. No. 6,415,449 to Duplock discloses a survival garment made of high stretch elastomer designed to protect the wearer from the effects of immersion in cold water. The garment has “skin tight” fittings at the cuffs and sleeves that may be made from an elastic material that comprises a high stretch elastomer coated with a material of low friction, such as neoprene, for allowing easy donning and doffing of the garment.
A patch of low friction coefficient material placed either on the skin or on the surface that will be next to the skin in locations where sheer trauma is likely to occur is disclosed in U.S. Pat. No. 6,362,387 to Carlson et al. Therein is disclosed a patch of low friction material such as a film of polytetrafluoroethylene sized to provide an area of low friction support for a portion of a human body relative to an object such as a shoe or prosthetic sock. The layer of low friction material is adhered to the surface of the object that bears on the skin and faces the skin such as a sock fabric. In a preferred embodiment PTFE is bonded to a fabric layer of Lycra.
U.S. Pat. No. 5,829,057 to Gunn discloses an article such as clothing, footwear and the like which incorporate fabrics or chemicals having low coefficient of friction. The patent notes that some material fibers inherently have a low coefficient of friction, such as TEFLON®, KYNA® and GORTEX®. In addition, the use of chemicals to treat material fibers or finished materials that do not inherently have a low coefficient of friction is taught. The articles incorporating fabrics with chemicals with a low coefficient of friction are intended to minimize the development of irritations, blisters and calluses including gloves, shoes and sportswear.
It is an object of the present invention to provide a medical compression garment having an integral donning aid.
Another object of the present invention is to provide a compression garments having a low friction zone made with the addition of or completely from low friction yams or by coating/laminating of the inside surface of a garment with the low friction materials.
Yet another object of the present invention is the provision of an easy donning aid embedded in a stocking at discrete locations that provides more comfort for the patient and increases compliance and use of medical compression garments.
It has been found that the foregoing objects may be accomplished in accordance with this invention by providing compression garments of this invention having a low friction zone made with the addition of low friction material on the inside surface of a garment in discrete locations to decrease friction between skin and fabric, thus providing easier donning of compression garments.
Low friction yarns may be positioned in a specific pattern or plated together with other yarns, or used in combination with other yarns, preferably with highly stretchable spandex yarns to compensate for low elongation of PTFE yarns. Depending on the manufacturing methods, circular or flat-bed knitted, the low friction area should be positioned at the inside of the garment. To provide better contact with the patient's skin it is advantageous to use covered spandex with low friction yarns, “so called” inlay yarn in circular knitted products.
In a first embodiment, the medical compression garments (stocking, arm sleeve, gauntlet, glove, or other) of this invention have an integral donning aid that is knitted into the main portion of the garment that contains elastic yarns and exerts pressure on the corresponding body part. There is at least one integral donning area deferring a low friction zone strategically located on the internal surface of the garment (e.g. at the narrowest and critical for donning process parts of the garment) to facilitate donning of the garment and improve patients' compliance.
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
The compression garments of this invention have a low friction zone made with the addition of or completely from low friction yarns or by coating/laminating of the inside surface of a garment with the low friction materials to decrease friction between skin and fabric, thus providing easier donning of compression garments. Medical compression garments can be produced as seamless garments using circular knitting machines, or seamed knitted garments made using flat-bed knitting machines, or sewn from elastic fabric using proportional design to provide necessary compression level at specified positions on the limb or body. The design of compression garments of this invention needs to combine two opposite requirements: provide easy donning and at the same time prevent sliding during wearing. Therefore, it is important to understand that low friction material can be used only at specified locations, because using material through the complete garment will result in sliding of the garment from the limb and losing of its therapeutic effect.
In a first embodiment, the medical compression garments (stocking, arm sleeve, gauntlet, glove, or other) of this invention have an integral donning aid that is knitted into the main portion of the garment that contains elastic yarns and exerts pressure on the corresponding body part. There is at least one integral donning area deferring a low friction zone strategically located on the internal surface of the garment (e.g. at the narrowest and critical for donning process parts of the garment) to facilitate donning of the garment and improve patients' compliance.
Low friction yarns made of different materials can be used, including but not limited to polytetrafluoroethylene (PTFE) homopolymer yarns: Profilen (Lenzing), Tenara and/or Rastex (Gore) Teflon (DuPont); melt spun fluoropolymeric fibers made of hexafluoropropylene and of tetrafluoroethylene-hexafluoroproplyene copolymers (DuPont U.S. Pat. No. 6,048,481), polyamide yarns modified with ultra-high molecular weight silicone and known as Freelon™ fiber, yarns made of physical blends of polyamide or polyester with PTFE or with meltable fluoropolymers, nylon and polyester yarns with surface modified with silicone, and other yarns with the coefficient of friction at least 30% lower than that of the other yarns used to make a garment, i.e. nylon, polyester, cotton, or the like. Other materials applicable for the purpose of this invention include, but are not limited to, low friction tapes, films and liquids, including PTFE suspensions, capable of creation of necessary patterns on specified low friction zones of the garment and made of PTFE, polychlorotrifluoroethylene (PCTFE), poly(vinylidene) fluoride, poly(vinyl) fluoride copolymer, fluorinated ethylene propylene and other copolymer and blends of fluoro-containing polymers, and silicone polymers and copolymers.
The low friction material is applied in such a way that it will not affect stretch and compression characteristics of the garment. In one embodiment, low friction material is integrally knitted in the garment or woven in the fabric. Low friction yarns may be positioned in a specific pattern or plated together with other yarns, or used in combination with other yarns, preferably with highly stretchable spandex yarns to compensate for low elongation of PTFE yarns. Depending on the manufacturing methods, circular or flat-bed knitted the low friction area should be positioned at the inside of the garment. To provide better contact with the patient's skin it is advantageous to use low friction yarns, as knitting or “so called” inlay yarn in circular and flat-bed knitted products.
Another embodiment of a stocking 10 of the present invention is shown in
In another embodiment a low friction permanent finishing on the inside surface of the fabric, or a narrow strips or dots of low friction material (tape, film, fabric) is attached to the garment by coating, laminating, or any other applicable method. An example of such garment is shown in
Another embodiment of the garments of the present invention provides sewing a patch 50 of low friction material to the inside of a garment 10 such as shown in
Although a preferred method of making the garments of the present invention is on a circular knitting machine, it should be understood that other methods of manufacturing may be used, such as flat-bed knitting. Examples of the garments of this invention using flat-bed knitting are shown in
In
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
