1.
Field of the Invention
This invention relates to apparatus and method for the treatment of lymphedema. More particularly it relates to a wrap having a series of bladders applied to the trunk of the body, wherein the bladders are compressed and decompressed on an individual basis to stimulate the lymphatic system.
2. Description of the Prior Art
The lymphatic system consists of lymph vessels, lymph nodes and lymphoid tissues and is a secondary system within the circulatory system that removes waste. Unlike the closed-loop blood circulatory system, the lymphatic system works according to a one-way principal. That is, the lymphatic system is a drainage system to drain away lymph which continually escapes from the blood in small amounts. The lymph is first collected at the lymph capillaries, which in turn drain into larger vessels. The lymph is pumped in and out of these vessels by movements of adjacent muscles and by contractions of the walls of the larger vessels, and moves through the lymphatic system in one direction. Foreign matter and bacteria are filtered at various lymph node groups after which the fluid empties into the venous portion of the blood system, mainly through the thoracic duct. A healthy person will drain one to two liters of lymph fluid through this duct every 24 hours. Without proper drainage into the duct, lymphedema results.
Lymphedema is an accumulation of a watery fluid in the body causing a swelling or edema of the affected area. The swelling causes pain, discomfort, disfigurement and interference with wound healing and, if left untreated, can cause fibrosis. Fibrosis is a hardening of the tissue in the affected area which may further complicate the drainage process and can cause life-threatening conditions, such as infections. Lymphedema may result from surgery when the lymph nodes are removed in order to prevent the further spread of cancerous conditions, such as with a mastectomy or prostectomy, and may also be caused by filariasis. Lymphedema may be primary or congenital.
In recent years, several common therapies for lymphedema have been proposed. Special bandages, such as a limb compression sleeve or stocking, have been utilized to help prevent accumulation of fluid in a limb by holding the tissue tightly. This treatment is incomplete, however, because it treats the limb only and does nothing to actually move the fluid. This treatment is also uncomfortable (and may be painful) and is not easily adaptable to the trunk of the body. In application to the limb, this treatment may interfere with mobility.
Pneumatic compression devices have also been used to assist limb lymph drainage by increasing the tissue pressure, thus, forcing fluid along the lymphatic system. This treatment approach, however, is incomplete because it treats the limb only. This treatment approach may cause fibrosis or accumulation of fluids in non-affected areas. The high pressure required to force the fluid along the system is uncomfortable or painful, while lower pressure devices result in an increase in therapeutic time.
Another approach is manual lymph drainage (MLD), a gentle manual treatment technique which improves lymphatic system functioning through a highly specific massage, which provides mild mechanical stimuli to the lymphatic system. MLD has the advantage of being able to treat the entire lymphatic system, including the arms, legs and trunk of the body. The MLD treatment technique applies just enough pressure to massage pooled fluids from larger areas toward specific lymph nodes within the body by mechanically stimulating the lymphatic system to cause contraction of the lymph collectors sufficient to help move the pooled fluids by promoting reabsorption of the pooled fluids within the surrounding tissues. Too much applied pressure will cause the lymph collectors to go into spasm. This technique is effective but also expensive, however, as a person trained in the MLD technique is required to perform the massage therapy.
U.S. Pat. No. 5,453,081, issued to Hansen, suggests an apparatus for generating air pressure pulses which are delivered to a vest or mattress accommodating a person. A diaphragm located within a housing is connected to a wave generator and amplifier operable to vibrate the diaphragm. The vibrating diaphragm produces air pressure pulses, which are delivered to the air accommodating receiver, and which subject the person to repetitive force pulses. The housing has an enclosed chamber accommodating the diaphragm, which divides the chamber into two separate portions, wherein air under pressure may be supplied with a pump to the chamber to pressurize the apparatus, as well as the receiver. A coil connected to the diaphragm is operable to vibrate the diaphragm to pulsate air in the chamber.
U.S. Pat. No. 5,437,610, issued to Cariapa et al., suggests a portable hydraulic extremity pump apparatus for the treatment of edema. This apparatus consists of a flexible compression unit that wraps around an individuals extremity. The unit includes a plurality of prefilled bladders, each containing a separate compression bladder which are connected to a hydraulic pump through valves. The valves, pump, and pressure sensors, which connect to the prefilled bladders, all connect to a programmable control processor to operate the valves and to pump and monitor the bladder pressures. The occurrence of edema is detected by monitoring an increase in pressure in the prefilled bladders. Once edema is detected, the control processor activates the pump and opens valves connected to the compression bladder in a sequential manner to create a sequential pressurization and wave of compression moving proximally on the extremity.
U.S. Pat. No. 5,052,377, issued to Frajdenrajch, suggests an apparatus for massaging parts of the body by sequential cyclic pressure having a massaging boot comprising a plurality of juxtaposed inflatable cells. An inflating conduit is connected to each cell through a series of distributors for receiving a control fluid. Each distributor has a movable membrane arranged to permit passage of the inflating fluid in a downstream direction when the local inflating pressure reaches a value which is a function of the pressure of the control fluid. The cells are inflated in series, one after another, and then deflated in a cyclic manner.
U.S. Pat. No. 5,014,681, issued to Neeman et al., suggests a method and apparatus for treating a body part by applying intermittent compression through an inflatable sleeve applied to and enclosing the body part. The inflatable sleeve is divided into successively overlapping inflatable cells. Pressurized fluids are applied cyclically to successive groups of cells to successively inflate each group, while at the same time deflating a preceding group. As successive groups of cells are inflated (while the remaining cells are deflated), a compression wave is introduced in the sleeve which subjects successive portions of the body part to compression.
U.S. Pat. No. 4,573,453, issued to Tissot, suggests a pneumatic massage apparatus which includes an inflatable sleeve having an inner and outer sheath with lateral partition walls extending between the inner and outer sheaths. The inner and outer sheaths are formed of air-impermeable, non-elastic material and the lateral partition walls are formed of a flexible air-impermeable, non-elastic material. The partition walls and inner and outer sheaths define separate inflatable chambers, adjacent chambers being separated by a partition wall. When a first chamber has been inflated, its feed conduit is closed and the following chambers are inflated in turn to the same feed pressure. The result causes a deformation of the walls of the first chamber, and a slight increase in the internal pressure in this first chamber. Step by step, with the same feed pressure, the appearance of a pressure gradient is created.
U.S. Pat. No. 2,361,242, issued to Rosett, suggests a pneumatic suit or garment adapted to be applied to limbs of a patient, wherein the pneumatic suit has a series of laterally disposed pockets, each of which is provided with a fluid-type flexible bag. The bags are inflated one after another in groups, so as to cause the exertion of waves of pressure from the extremities of the limbs and from the lower portion of the torso of the patient towards the region of the heart. After each bag is inflated, it is immediately subjected to a source of sub-atmospheric pressure to accelerate the removal of air therefrom and to accentuate the effect. Rosett suggests the pneumatic suit or garment being applied to areas including the arms and legs and lower trunk.
U.S. Pat. No. 5,626,556, issued to Tobler et al., is generally directed to the radio frequency welding of a VELCRO component to a compression sleeve, an alternative to fastening same by sewing. Tobler et al. generally show a compression sleeve of symmetrical design for the leg which includes a series of pneumatically paired or linked chambers (i.e., ankle chambers 38a/38b, calf chambers 38c/38d, and thigh chambers 38e/38f). Each pneumatically paired chamber includes a ventilation channel or plenum which partially traverses the chamber, thereby defining a bifurcated end for each pneumatically paired chamber. The ventilation plenums are intended to cool the underlaying leg via continuous air circulation thereto.
The present invention provides an apparatus for mechanical stimulation of the lymphatic system for the treatment of lymphedema. A lymphedema treatment system in accordance with the present invention includes a wrap having a plurality of elongate and flexible bladders applied to the trunk of the body. The bladders are compressed and decompressed on an individual basis to stimulate the lymphatic system to provide for drainage of pooled fluids by massaging the pooled fluids within the trunk section of the body towards lymph nodes in the neck or groin of the body. Compression and decompression of the bladders may be provided by a pump.
In a preferred embodiment of the present invention, the apparatus for the treatment of lymphedema may comprise a plurality of elongate and flexible bladders, wherein the plurality of bladders has an orientation adopted to engage the trunk of the body and move pooled fluids within the lymphatic system towards a particular region of the body or away from a particular region of the body. The particular regions of the body may be specific lymph node groups which include the axillary node group, the pelvic node group or the groin node group as well as the thoracic duct. The orientation of the plurality of bladders relative to the particular region may be arcuate so that the plurality of bladders being coextensive and sequentially arranged in a fixed relation may engage the trunk of the body to radially move the pooled fluids within the lymphatic system to the particular region of the body.
In a preferred embodiment, each particular one of the plurality of bladders may be sequentially pressurized and depressurized in a sequence to provide mechanical stimulation of the lymphatic system similar to Manual Lymph Drainage (MLD) massage. In the preferred embodiment, a pumping system is in fluid communication with each particular one of the plurality of bladders and is programmable to sequentially pressurize and depressurize each particular one of the plurality of bladders. The pumping system may be comprised of a pneumatic pump and a plurality of pneumatic hoses to couple the pneumatic pump to each particular one of the plurality of bladders. Each particular one of the plurality of bladders may be pressurized to engage the trunk of the body at a therapeutic pressure. The lymphatic system is mechanically stimulated when each particular one of the plurality of bladders being both pressurized to the therapeutic pressure and depressurized causes contraction of lymph collectors sufficient to move pooled fluids by promoting reabsorption of the pooled fluids within the surrounding tissues without causing the lymph collectors to go into spasm. In the preferred embodiment there may be a predetermined waiting period between a first particular one of the plurality of bladders being fully pressurized and fully depressurized (i.e., a set, pre-determined period from the start of pressurization to a return to atmospheric condition). In addition, depressurization of the first particular one of the plurality of bladders may begin before pressurization of a second particular one of the plurality of bladders begins.
The preferred embodiment may further comprise a wrap sized to wrap around a portion of the trunk of the body to receive and hold each one of the plurality of bladders within a corresponding one of a plurality of compartments. The plurality of bladders are held in an orientation to engage the trunk of the body and move pooled fluids within the lymphatic system either towards or away from specific lymph node groups which include the axillary node group, the pelvic node group or the groin node group. The orientation may be arcuate relative to the particular lymph node group. The wrap may maintain the plurality of bladders in a coextensive relationship such that each particular one of the plurality of bladders is adjacent to one or two other ones of the plurality of bladders. The wrap may be constructed of a stretchable material to accommodate expansion and contraction of the bladders as the bladders are sequentially pressurized and depressurized. The wrap may also limit the maximum diameter under pressurization of each one of the plurality of bladders within the plurality of compartments.
The present invention further provides a method of body manipulation in furtherance of treating lymphedema. The method includes providing a wrap adapted to fit about a body extremity and applying same about the body extremity, more particularly, providing and applying a wrap having a trunk region and limb regions, and a plurality of compartments distributed throughout the regions. Each of the compartments of the plurality of compartments of the wrap regions is capable of selective pressurization and depressurization, as by use of a controllable pneumatic system, or the like, known to those of skill in the art. The method further includes preparing the body extremity for receipt of lymph fluid via a first pressurization and depressurization sequence of select compartments within select regions of the regions of the wrap, and draining lymph fluid from the body extremity via a second pressurization and depressurization sequence of select compartments within select regions of the regions of said wrap. By this method, the lymphatic system is stimulated so as to promote reabsorption of pooled lymph fluid within surrounding tissue.
Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein:
Referring now to the drawings, wherein like reference numerals refer to like elements throughout the several views,
In the preferred embodiment, bladders 44, 46, 48, 50, 52, and 54 are held within compartments 24, 26, 28, 30, 32, and 34 of wrap 12 so that the bladders have a generally arcuate shape and are sequentially pressurized and depressurized to engage lower trunk 16 of human body 18 to radially move pooled fluids. The pooled fluids are moved within the lymphatic system of human body 18 either in the direction shown by arrows 64, 66 and 68, or in a direction opposite to the direction shown by arrows 64, 66 and 68. The bladders are oriented to be arcuate relative to three lymph node groups such that radial lines extending from each bladder converge (or diverge) towards each one of the lymph node groups (see also,
In the preferred embodiment, there is a predetermined waiting period of one to three seconds between pressurization and depressurization of each bladder (i.e., the period from the start of pressurization to a return to an atmospheric condition), more than a single bladder being at a pressure greater than-atmospheric during the sequenced mechanical stimulation. Thus, each of bladders 44, 46, 48, 50, 52, and 54 are pressurized for one to three seconds to provide the mechanical stimulation to the lymphatic system. Each bladder is depressurized before pressurization of the next bladder begins. In
Compartments 24, 26 and 28 are constructed of a combination of materials. A first layer 90 overlays each of bladders 44, 46 and 48 and is the side of wrap 12 that is in a contact relationship with lower trunk 16 of human body 18. First layer 90 is preferably constructed of a stretchable material and stretches when any of bladders 44, 46 or 48 are fully pressurized to provide the therapeutic pressure to lower trunk 16. The therapeutic pressure is between 20 mm Hg and 45 mm Hg (0.387 and 0.87 psi). Second layer 92 overlays each of bladders 44, 46 and 48 on the side of wrap 12 opposite first layer 90. Second layer 92 is preferably constructed of a durable cotton material. Third layer 94 overlies second layer 92 and provides an outer cover for wrap 12. Third layer 94 is preferably constructed of a cotton material.
Bladders 126, 128, 130, 132, 134 and 136 when pressurized and depressurized provide a gentle massaging action which provides a mechanical stimulation similar to manual lymph drainage massage to the lymphatic system so that proper drainage may occur. The stimulus is provided by sequential inflation of each bladder. The therapeutic pressure is measured between bladders 126, 128, 130, 132, 134 and 136 and upper trunk 112 and is between 20 mm Hg and 45 mm Hg (0.387 and 0.87 psi) in order to promote reabsorption from the surrounding tissues. Too much pressure against upper trunk 112 will cause the lymph collectors to go into spasm and reduce effectiveness. The plurality of bladders may be individually and sequentially pressurized and depressurized in the direction shown by radial arrows 138, 140, and 142 (converging toward axillary node group 80) to promote drainage of fluids in a direction towards axillary group 80. In terms of the present invention, the bladders 126, 128, 130, 132, 134 and 136 are “oriented” (configured and sequentially pressurized and depressurized) to direct drainage in a direction towards axillary group 80. The bladder configuration is generally arcuate, while the “radial” arrows 138, 140 and 142 point in a direction generally perpendicular to a tangent of the arcuate bladder.
The figures illustrate that alternative constructions in accordance with the present invention may move pooled fluids within human body 18 from several regions to a particular node group, or from a particular region to several node groups, for instance, with reference to
Each bladder of the illustrated embodiments has a generally arcuate configuration. The configuration and sequential pressurization/depressurization provides an orientation towards one or more node group(s). That is, radial lines extending from each bladder along its length extend generally toward one or more node groups. Configuration and direction provide an “orientation”. Orientation is established by the direction of sequential pressurization/depressurization of the bladders and the configuration of the bladders on the body. The length of each bladder is optimally determined to move pooled fluids toward a node group. While it is expected that each bladder will be arcuate to some degree, the bladders need not be arcuate along their entire length nor need each bladder be arcuate so long as the bladders are “oriented” toward a node group, as described.
Referring generally to
Referring now to
The limb regions of the wrap preferably are intended to correspond with (i.e., overlay) the thigh, calf, including the ankle, and foot. Alternately, the limb regions of the wrap may correspond with (i.e., overlay) the biceps, forearm, including the wrist, and hand, wherein the body extremity subject to treatment is an upper body extremity as shown in
A wrap suitable for implementing the preferred method of body manipulation may be consistent with that disclosed herein above, namely a wrap having a number of compartments which are sized to receive and hold a number of bladders which are in fluid communication with a pneumatic pump (see
As previous noted, MLD is highly desirable for the therapeutic results obtainable. MLD massage therapists are taught to treat five upper body sections (i.e., trunk, shoulder, biceps, forearm, and hand), and four sections of the lower body (i.e., trunk, thigh, calf, and foot). The MLD treatment technique applies just enough pressure to massage pooled fluids from larger areas toward specific lymph nodes within the body by mechanically stimulating the lymphatic system to cause contraction of the lymph collectors sufficient to help move the pooled fluids by promoting reabsorption of the pooled fluids within the surrounding tissue. More particularly, the MLD treatment technique is performed in a proximal to distal pattern with respect to the body trunk (e.g., in the four lower body sections as follows: trunk, thigh, calf, and foot), with the hand being applied to the body so as to gently direct the fluid in the proximal direction (i.e., toward the body trunk).
The body extremity, once fitted with the wrap, undergoes a preparation step which includes a first pressurization and depressurization sequence of select compartments within select regions of the regions of the wrap. The preparation sequence generally starts in the trunk region and proceeds to a distal limb region of the several limb regions. More particularly, the sequence includes the consecutive pressurization and depressurization of each compartment of the compartments distributed throughout the selected region of the regions of the wrap, beginning with a distal chamber and proceeding to a proximal chamber thereof.
Referring now to
After the preparation of the body extremity for receipt of lymph fluid, the body extremity undergoes a drainage step which includes a second pressurization and depressurization sequence of select compartments within select regions of the regions of the wrap such that the lymphatic system is stimulated so as to promote reabsorption of pooled lymph fluid within surrounding tissue. The general sequence or order of pressurization and depressurization is from the distal region (i.e., R4) of the wrap regions sequentially or consecutively to adjacent regions (i.e., R3 to R2) until reaching the proximal region (i.e., R1). The compartments of each of the regions are consecutively pressurized and depressurized in a direction from the distal chamber to the proximal chamber (i.e., from Cn toward C1). In summary, the preferred drainage sequence or second pressurization/depressurization sequence proceeds as follows, R4, Cn→C1; R3, Cn→C1; R2, Cn→C1; and R1, Cn→C1, with the path from Cn to C1 being preferably consecutive, but not so limiting. As in the case of preparation, patient symptoms may dictate that the selective pressurization and depressurization of the compartments of the regions not be uniform, either as to sequence (i.e., pressurization and/or depressurization order), quantum or duration of pressurization, from region to region, or within any given region. The sequences of the method are preferably selected, for instance as by programming of a pneumatic controller or the like, on a patient specific basis for optimal therapeutic effect.
As previously discussed, MLD is a particularly effective lymphedema treatment methodology, heretofore requiring the specialized skill of a trained clinician, typically one employed at an urban health care facility. The wrap systems and structures of the subject invention impart a systematic low pressure gradient to the edema effected body part or region as previously described with respect to
It is imperative that the wrap structure be or form a body conforming assembly. Furthermore, and as a practical matter, the wrap structure or assembly is desirably configured such that each of the discrete chambers of the plurality or array of discrete chambers circumscribe a segment of the portion of the human form underlaying the wrap structure (i.e., forms a substantial continuous ring there around, as is especially the case with a limb, as opposed to the torso or portions thereof). A plurality of tabs, or fastening structures more generally, desirably extend from or beyond the array of chambers of the wrap structure in furtherance of conforming specific portions or segments thereof to corresponding portions of the affected body region.
As will be subsequently discussed, the wrap structure of the subject invention is characterized in part by discrete, non-uniformly curved chambers capable of selective, systematic, reversible pressurization. The periphery of the wrap structure is further especially configured so as to, alone or in combination with another wrap structure or structures, suitably form select circumscribing compartments which fit (i.e., correspond to) the underlaying body contour. It is the profiled margin (i.e., outer dimensional design) of the wrap structure which contributes to the overall wrap fit, the arcuate configuration of the chambers being essential due to their need to conform to body contours and maintain position with respect to lymphatic flow (i.e., maintain the developed or developing pressure gradient perpendicular to lymphatic flow).
As a preliminary matter,
With general reference to
The first wrap structure or assembly 202 includes a plurality 204 of discrete continuous compartments 206 formed interior of a margin 208 of a composite material panel 210. As previously detailed, each of the compartments 206 of the array of compartments 204 are adapted for individual pressurization/depressurization in furtherance of MLD simulation. Fastening means 212, as will be later be detailed with respect to the specific wrap structures, extend from the margin 208 so as to permit linkage of the structures so as to form the system 200. The second wrap structure 202 is similarly characterized by an array 204 of discrete continuous compartments 206 which are formed integral to a composite material panel 210 and interior of a margin 208 thereof. The margin 208 preferably includes fastening means 212 extending therefrom. The margin of the first wrap structure advantageously has a first configuration 213 (see e.g.,
Referring now generally to the wrap structures of
Each of the discrete tubular chambers 206 (i.e., flat reversibly inflatable compartments) formed in the composite material panel 210 are generally continuous throughout their length, and preferably, but not necessarily have a uniform or substantially uniform cross-section there along. As will be later detailed, the pneumatically isolated chambers 206 are preferably formed by radio frequency welding of opposingly paired adjacent sheets of material amenable to such procedure. As such, each reversibly expandable compartment 206 so formed may be fairly characterized as having opposingly paired lateral edges 214 (i.e., ends) and opposingly paired longitudinal edges 216 (i.e., the “wall” of the chamber is not continuous, in contradistinction to the bladder 44 of
Each of the wrap structures of the subject invention requires a flexure (i.e., bending), or more broadly, a manipulation, in furtherance of application to an affected body part. The physical point of manipulation (i.e., a wrap axis) 218 of the wrap structures generally passes through or traverses each of the chambers 206 of the array of chambers 204.
A further feature of the chambers 204 of the array of chambers 206 are pneumatic couplings or stems 220. As each discrete chamber 206 includes a pneumatic coupling 220, each discrete chamber 206 is pneumatically isolated, and is therefore independently operable consistent with the previously detailed methodology.
To provide a more finished look to the wrap structures, and assist fluid ingress/egress via conduit management, wrap structure covers 222 (
The wrap structure 202 generally has a periphery or outer limit 236 defined at least in part by the margin 208 of the composite material panel 210. As previously noted, the wrap structure 202 generally includes fastening means 212 to facilitate the formation of a wrap assembly or wrap system 200 (i.e., the union of two or more wrap structures). Preferably, but not necessarily or exclusively, the margin 208 includes at least a single tab 238, or single set of tabs. By this construct, the tabs 238 are integral to the wrap structure. The tabs 238 preferably include a component 226 of a hook and loop fastening system so as to quickly and easily fit the structure 202 upon the affected body part, as well as unite the single wrap structure to one or more thereof in furtherance of forming a wrap assembly or system 200. The tabs 238, in combination with straps 240, as the case may be (
Referring now specifically to
As shown, compartments C5-C7 are intended to correspond to bicep placement, C8-D4 to forearm placement, and D5-D8 to hand placement. It is to be understood that select chambers may be eliminated (e.g., C6 and D2) to accommodate a shorter arm length. Generally, the curvature of each of the chambers diminishes proceeding from chamber C1 (arm pit area) to D8 (finger tip), more particularly, as the chambers proceed from chamber C1 to D8, their angular orientation with respect to the wrap axis increases (i.e., the chambers extend in opposing directions from the wrap axis, the angle associated therewith decreasing from C1 to D8) . Finally, each longitudinal region of the warp structure includes dedicated fastening means 212, with further fastening means incorporated into the margin 208 adjacent chamber C1.
Referring now specifically to
Referring now specifically to
Referring now specifically to
The composite material panel of the subject wrap structures greatly enhances the body conforming quality of the wrap structure. Functionally, the composite material panel of the wrap structure is required to be reversibly and selectively expandable (i.e., the panel has a variable non-constant thickness throughout its areal extent during MLD simulation), and be conforming to portions of the human form (i.e., have an inherent reversible stretch quality or character in addition to having a fastening system which permits the wrap to be fit or worn in the first instance). An especially advantageous construct for the composite material panel for the subject wrap structures is illustrated in
With reference to
The opposingly paired exterior sheets 250 preferably comprise a two layer laminate. Fabric 254 having a multidirectional stretch is united with a resilient foam layer 256, as for instance by flame lamination. It is particularly advantageous that the fabric be breathable, generally skin “friendly,” and have a preferred direction of stretch or elongation. That is to say, although the fabric 254 has a four way stretch, it is capable of preferential elongation or axial stretch. The fabric 254 of the exterior layer 250 preferably has a maximum stretch direction at about a 45° angle from a machine direction (i.e., the fabric width or “fill” designation, as opposed to the “warp” of the fabric) of or for the fabric. One know laminate exhibiting the desired characteristics is that offered by American Foam & Fabric of Greenville, S.C., namely a 100% nylon Alpine headliner VL-1879 having a sheet of a S1300B open cell polyurethane foam laminated thereto. The foam thickness is preferably 0.135 inches, the exterior sheet or laminate having a finished thickness of about 0.125 inches. To most closely mimic MLD utilizing the subject wrap structures, the array of pneumatic chambers, or the margin more generally, of the structure is to be “laid out” (i.e., oriented) with respect the fabric 254 of the exterior sheet 250 as shown in the figures, namely
The opposingly paired adjacent interior sheets 252 form or define the fluid retaining portion of the chambers. The interior sheets 252 preferably comprise a 5 mil thick 85A durometer polyether (i.e., polyurethane). Subsequent to forming the exterior laminate sheets 250, the four sheets are introduced into the production machine and RF welded to form the wrap and chamber welds simultaneously.
While a preferred embodiment of the present invention has been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention. Changes may be made in details, particularly in matters of shape, size, material, and arrangement of parts without exceeding the scope of the invention. Accordingly, the scope of the invention is as defined in the language of the appended claims.
This application is a continuation-in-part of co-pending application Ser. No. 09/730,081 filed Dec. 05, 2000 which is a continuation-in-part of U.S. Pat. No. 6,179,796 filed Apr. 11, 1997.
Number | Date | Country | |
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Parent | 10230840 | Aug 2002 | US |
Child | 11069104 | Mar 2005 | US |
Parent | 09730081 | Dec 2000 | US |
Child | 10230840 | Aug 2002 | US |
Number | Date | Country | |
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Parent | 08843023 | Apr 1997 | US |
Child | 09730081 | Dec 2000 | US |