Patent Publication Number: US-2009227918-A1

Title: Compression device having an inflatable member with a pocket for receiving a counterforce component

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a compression device, and more particularly to a foot cuff including an inflatable member with a pocket for receiving a counterforce component. 
     BACKGROUND 
     Compression devices for applying compressive forces to a selected area of a wearer&#39;s anatomy are generally employed to improve blood flow in the selected area. Compression devices that provide intermittent pulses of a compressed fluid (i.e. air) to inflate at least one inflatable chamber in a cuff or sleeve are particularly useful. This cyclic application of pressure provides a non-invasive method of prophylaxis to reduce the incidence of deep vein thrombosis (DVT), and the like. These compression devices find particular use during surgery on patients with high-risk conditions such as obesity, advanced age, malignancy, or prior thromboembolism. Patients who develop this condition often have swelling (edema) and tissue breakdown (venous stasis ulcer) in the lower leg. When a DVT occurs, the valves that are located within the veins of the leg can be damaged, which in turn can cause stasis and high pressure in the veins of the lower leg. 
     Generally, these compression devices are fluidly coupled to a source of pressurized fluid by one or more air tubes. Additionally, each compression device includes a flexible shell having one or more bladders disposed therein. The compression device is placed around the patient&#39;s foot or other selected portion whereupon a pressurized fluid is delivered into the bladder creating pressure at the part or parts of the body in contact with the bladder. 
     Compression cuffs adapted for use with a patient&#39;s foot may be used by themselves or combined with one or more additional compression cuffs or sleeves that are disposed on portions of a patient&#39;s leg for improving the treatment regimen. In general, each of the additional compression sleeves includes a plurality of separate inflatable chambers that are progressively arranged along a longitudinal axis of the sleeve from a lower portion to an upper portion of the limb. A pressure source, e.g. a controller, is provided for intermittently forming a pressure pulse within these inflatable chambers from a source of pressurized fluid during periodic compression cycles. The compression sleeves provide a pressure gradient along the patient&#39;s limbs during these compression cycles which progressively decreases from the lower portion to the upper portion of the limb (e.g. from the ankle to the thigh). 
     Compression cuffs that are adapted for use with a patient&#39;s foot generally include a heel strap with a tab portion that is adapted to fit around a portion of the patient&#39;s heel. This arrangement allows the compression cuff to be wrapped around and releasably attached to the patient&#39;s foot. The compression cuff may include a generally rigid sole to direct expansion of the inflatable chamber toward the wearer&#39;s foot. The rigid sole needs to be located under that portion of the inflatable that is acting on the portion of the foot to produce blood flow out of the foot. Conventionally, the rigid sole is temporarily attached to the bladder by double stick tape. Final location and positioning of the rigid sole may be carried out by stitching. For example, the bladder is typically stitched to an outer wrap of the foot cuff. The stitching can be arranged so that it captures the rigid sole in position relative to the bladder, as well as the outer wrap. This requires care and precision in manufacturing the foot cuff. 
     Examples of compression cuffs are disclosed in U.S. Pat. Nos. 4,013,069 and 4,030,488 to Hasty, U.S. Pat. Nos. 4,029,087 and 5,795,312 to Dye, U.S. Pat. No. 5,626,556 to Tobler et al., and U.S. patent application Ser. No. 11/761,212 to Meyer et al., all of which are currently owned by Tyco Healthcare Group LP and are incorporated by reference herein in their entireties. Other examples of compression cuffs are disclosed in U.S. Pat. Nos. 4,696,289 to Gardner et al., 5,989,204 to Lina and 5,345,260 to Cook. An example of compression treatment method is disclosed in U.S. Pat. No. 6,231,532 to Watson et al., which is owned by Tyco Healthcare Group LP, the contents of which are hereby incorporated by reference herein in their entirety. 
     SUMMARY 
     In one aspect, a compression foot cuff for applying compression to a foot of a wearer generally comprises an inflatable member including first and second of fluid impermeable layers secured to one another to define an inflatable chamber. The foot cuff comprises a generally rigid counterforce component. The inflatable member is formed to define a pocket receiving the counterforce component therein. 
     In another aspect, a method of making a foot cuff device for applying compression to a foot of a wearer generally comprises forming a bladder by joining together generally opposed first and second layers of fluid impermeable material to form a chamber. A generally rigid counterforce component is positioned in a pocket defined by the bladder so that the counterforce component is held in a selected orientation relative to the bladder in the pocket. 
     Other objects and features will be in part apparent and in part pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective of a first embodiment of a compression foot cuff in accordance with the present disclosure; 
         FIG. 2  is a perspective of a bladder of the foot cuff with a sole attached thereto; 
         FIG. 3  is an exploded view of  FIG. 2 ; 
         FIG. 4  is a section of the bladder with the attached sole taken along the line  4 - 4  in  FIG. 2 ; 
         FIG. 4A  is an exploded view of  FIG. 4 ; 
         FIG. 5  is a perspective of a second embodiment of a bladder of a foot cuff with a sole attached thereto, an outer layer of the bladder being broken away to show the underlying sole; and 
         FIG. 6  is an exploded view of the bladder in  FIG. 5   
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the drawings. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring now to the drawings, a compression foot cuff for applying compressive pressure to a wearer&#39;s foot is generally indicated at  10 . The foot cuff is adapted for use in a compression therapy system, which further includes a supply of pressurized air (not shown) and tubing connecting the supply of pressurized air to the foot cuff. 
     As shown best in  FIG. 1 , the foot cuff  10  includes an envelope, generally indicated at  12 , substantially enveloping or enclosing a bladder, generally indicated at  14 . The envelope  12  includes an inner contact layer  16  and an outer layer  18  secured to one another generally adjacent to corresponding perimeters of the layers to define an interior space for receiving and substantially enclosing the bladder  14  (broadly, “an inflatable member”) therein. The contact layer  16  and the outer layer  18  may be fixedly secured to one another at their peripheries, such as by heat welding, adhesives, sewing or other suitable ways. Alternatively, the contact layer  16  and the outer layer  18  may be releasably secured to one another. In use the contact layer  16  is adjacent to the wearer&#39;s foot and the outer layer  18  is located farthest from the foot. As used herein, the terms “inner” and “outer” indicate relative positions of respective components and surfaces with respect to the skin of the wearer&#39;s body part when the compression device is secured to the body part, and as such, an “inner” component or surface is more adjacent to the skin of the body part than an “outer” component or surface. 
     Contact layer  16  and outer layer  18  of the envelope  12  include ankle strap portions  19   a  and  19   b  respectively. Ankle strap portions  19   a ,  19   b  have a longitudinally projecting configuration for wrapping about a portion of the foot adjacent to the ankle. The ankle strap portions  19   a ,  19   b  can be sewn, RF welded, or sonic welded. However, in the illustrated embodiments, the ankle strap portions  19   a ,  19   b  are formed as one piece with the contact layer  16  and outer layer  18 , respectively. 
     Contact layer  16  of the envelope  12  is adapted for contacting the foot. Contact layer  16  is in one embodiment fabricated from a chemically treated material, with wicking ability, for wicking away moisture from the skin. In one embodiment, contact layer  16  includes a mesh-like fabric capable of wicking moisture away from the patient&#39;s skin. Furthermore, the contact layer  16  can be faced with a soft material toward the treatment surface of the patient. For example, the material can be a thin layer of open celled porous foam, napped cloth, or a layer of vapor permeable cloth permeable. It is understood that the cuff  12  may not include a contact layer within the scope of the present invention. 
     Outer layer  18  of the envelope  12  includes an opening  20  for permitting a pressurized fluid inlet passage therethrough. Outer layer  18  is configured for providing the attachment surface for a hook and loop feature of cuff  12 , as will be described in more detail herein below. Moreover, the outer layer  18  provides a soft material for cushioning effect against the top portion of the feet and may be fabricated from similar materials as contact layer  16  and in similar dimensions therewith for corresponding geometry. Alternatively, outer layer  18  may be fabricated from a laminated material, such as, for example, sontara fabric, open cell urethane foam, or loop fabric. It is understood that the cuff  12  may not include an outer layer within the scope of the present invention. 
     The bladder  14  is configured for positioning against the bottom portion of the foot. Referring to  FIG. 4 , bladder  14  includes outer and inner layers  22 ,  24  of air impermeable material (e.g., PVC) joined together in a suitable manner along a line  26  adjacent to their peripheries to define a single inflatable chamber  27 . The layers  22 ,  24  may be joined to one another such as by radio frequency (RF) welding. Other ways of joining the layers  22 ,  24  include sewing, adhesive, heat sealing, etc. It is understood that the bladder  14  can include more than one inflatable chamber  27  within the scope of the present invention. The inflatable chamber  27  of the bladder  14  is adapted for receiving and retaining a pressurized fluid (e.g. air) for exerting compressive pressure to the foot during successive pressure application cycles. The inflatable chamber  27  has an inlet member  34  (broadly, a port) and a tube  35  connected to the inlet member for air or fluid to be introduced into the chamber during the start of a compression cycle and to be exhausted to end the compression cycle. The inlet member  34  of the illustrated embodiment is a plastic component that is secured such as by heat welding or other means to the bladder  14 . It is understood that other ways of introducing air or fluid into the chamber  27  are within the scope of the invention. 
     A rigid sole (broadly, a counterforce component), generally indicated at  36 , is disposed between the outer layer  18  of the envelope  12  and the outer layer  22  of the bladder  14 . It is believed the sole  38  provides a counterforce to the outer layer  22  of the bladder  14  as the bladder is expanding to direct expansion toward the contact layer  16  and the user&#39;s foot. In this way, the inner layer  24  expands outward more than the outer layer  22  to direct compressive force toward the user&#39;s foot. The sole  38  may be constructed from a polypropylene material or other material within the scope of the invention. 
     The generally rigid sole  38  is received in a pair of spaced apart pockets  40  formed on the outer layer  22  of the bladder  14  to fix the position of the sole relative to the bladder. The pockets  40  are formed by attaching respective pieces of material to the outer layer  22  of the bladder  14 . For example, the pieces of material may be of the same material as the outer layer  22  of the bladder  14  (e.g., PVC) or may be of different material than the outer layer. The pieces of material forming the pockets  40  may be heat-welded or attached to the bladder  14  in other ways, such as by adhesives and sewing. In one example given without limitation, the sole  38  is inserted into the pockets  40  after the pieces of material are attached to the bladder  14 . In another example given without limitation, the sole  38  is properly positioned relative to the bladder  14  and the pieces of material forming the pockets  40  are attached to the bladder with sole in position. Although the illustrated embodiment includes two pockets  40  receiving the sole  38 , it is understood that the foot cuff  10  may have one or more than two pockets within the scope of the invention. For example and without being limiting, a single pocket may be formed by placing a single piece of material over the sole and attaching the single piece of material to the outer layer of the bladder to trap the sole between the single piece of material and the outer layer. 
     Hook fasteners  56 ,  58  are provided for securing the wrapped cuff  12  around a foot, and are positioned on the outer layer  18  of the cuff. Hook fastener  56  is mounted to strap portion  19   b  of outer layer  18  of foot cuff  12  while hook fastener  58  is mounted on a surface of outer layer  18 . In use, when ankle strap portions  19   a ,  19   b  are wrapped about the back of the foot, hook element  56  engages outer layer  18  to facilitate mounting of foot cuff  12  on the foot. An identification tab (not shown) may also be included for providing information such as the model number and manufacturer name. Hook fasteners  56 ,  58  may have tabs (not shown) without fastening material thereon to provide convenient gripping locations on the hook fasteners to thereby allow the practitioner to easily remove the hooks from the outer face  18   b  of outer layer  18 . The use and operation of the foot cuff  12  for applying compression therapy to the wearer&#39;s foot is generally known in the art and will not be described herein. 
     Referring to  FIGS. 5-6 , another embodiment of a foot cuff  110  is similar to the foot cuff of  FIGS. 1-4 , and therefore, like components are indicated by corresponding reference numerals, plus 100. In the present foot cuff  110 , opposing portions  142  of the line  126  defining the inflatable chamber  127  are sized and shaped to capture the sole  138  within the chamber. The portions  142  of the line  126  extend partially around the perimeter of the sole  138  in conformance with the shape of the adjacent part of the sole to fix the position of the sole relative to the bladder. For purposes of this embodiment, the portions  142  define pockets receiving the sole  138 . In one example without being limiting, the sole  138  is attached to the outer layer  122  within the inflatable chamber  127  to further fix the position of the sole relative to the bladder  114  and to further inhibit expansion of the bladder toward the outer layer. 
     Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. 
     When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. 
     As various changes could be made in the above constructions, products, and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.