U.S. patent application number 11/760771 was filed with the patent office on 2008-02-07 for mattress and method for reducing stress concentration when supporting a body.
Invention is credited to John Edward Rogers.
Application Number | 20080028532 11/760771 |
Document ID | / |
Family ID | 46328855 |
Filed Date | 2008-02-07 |
United States Patent
Application |
20080028532 |
Kind Code |
A1 |
Rogers; John Edward |
February 7, 2008 |
MATTRESS AND METHOD FOR REDUCING STRESS CONCENTRATION WHEN
SUPPORTING A BODY
Abstract
The present invention is an improved mattress or cushion
enclosed in a functional membrane that relates to the controlling
of flexible, rigid or visco-elastic foam, springs, air, fluids,
particulates, combinations thereof and foam density variations to
meet varying force support needs, as well as other support means
that have employed surface technology to modify the basic support
characteristics and the interface created therefrom with a
supported body in a manner intended to support the body optimally.
One potential non-health-related result of the implementation of
the present invention is to save national need for petroleum-based
products, forestry and expenses attributed to shipping with
complicated interface support methods normally incurred as a
shipping expense without a reusable feature.
Inventors: |
Rogers; John Edward;
(Candor, NC) |
Correspondence
Address: |
Herbert Joe
Suite 1009
1801 Crystal Drive
Arlington
VA
22202
US
|
Family ID: |
46328855 |
Appl. No.: |
11/760771 |
Filed: |
June 10, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10665059 |
Sep 18, 2003 |
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11760771 |
Jun 10, 2007 |
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Current U.S.
Class: |
5/706 |
Current CPC
Class: |
A61G 7/05769 20130101;
A61G 7/05753 20130101; A61G 7/05723 20130101 |
Class at
Publication: |
005/706 |
International
Class: |
A47C 27/08 20060101
A47C027/08 |
Claims
1. A pressure gradient dampening apparatus comprising: a foam body,
having one or more foam force accommodation zones formed at
pre-selected selected positions to accommodate and dampen forces
applied respectively to said foam body at or near said one or more
foam force accommodation zones; an enclosure member which is
reversibly, substantially impermeable to gas and fluid, and in
which said foam body is enclosed; valve means interface d with said
enclosure member for permitting introduction of an inflation medium
into, or exhaustion of an inflation medium from an interior space
of said enclosure member to impart said reversible, substantial
impermeability to said enclosure member; pump means, interfaced
with said valve means for facilitating said introduction of an
inflation medium into, or exhaustion of an inflation medium from an
interior space of said enclosure member.
2. The apparatus of claim 1 wherein said foam body comprises
multiple, separate foam components, and wherein said enclosure is
constructed to have multiple, separately sealed chambers in at
least some of which chambers said foam components reside, and
wherein valve means are independently operable to separately
introduce an inflation medium into, or exhaust of an inflation
medium from an interior space of each said chamber of said
enclosure member.
Description
CITATION TO PRIOR APPLICATION
[0001] This is a CONTINUATION-IN-PART with respect to U.S.
application Ser. No. 10/665,059, from which priority is claimed
under 35 U.S.C. .sctn. 120.
BACKGROUND OF THE INVENTION
[0002] 1. Field of The Invention
[0003] The present invention generally relates to mattresses. More
specifically, the present invention relates to improved mattress,
cushion and packaging material encased in a functional membrane
that uniquely reduces stress concentrations when supporting a human
or other body.
[0004] 2. Background Information
[0005] The human body can tolerate many forces, but one part of the
body subjected to continuous forces is the outer covering of skin
or "tissue."
[0006] When one walks, one generally hardens the underside of the
feet through intermittent pressure, abrasion and shear exerted by
their body mass against the earth's gravity. The underside of the
feet, as well as the hands and elbows, are made of special
underlying tissue to be able to withstand these forces and grow
calluses, whereas the underside of the arm is tender and not
designed for such loading.
[0007] Similarly, the tissue over the posterior (back) of the
heels, lateral trochanters (hipbones), ischial tuberosities
(sit-bones), malleolus (ankles), iliac crest (waist), scapula
(shoulder blades), ears and occiput (back of the head) are thinly
covered, poorly vascularized and cannot tolerate "loading" as well
as the feet and hands.
[0008] The noted bony areas are primarily sharp compared to the
feet, except, of course, the head or where underlying bony spurs
are established. Thus, when a load is applied to these surfaces,
one momentarily retracts from that load in an effort to protect the
trauma being applied to the tissue. However, without good sensation
at the surface of the tissue to send signals to the brain for
counteraction, one cannot respond appropriately and "tissue trauma"
results or skin is damaged. When exceedingly high forces are
applied, the pressure or shear adjacent to the applied force is
sufficient to damage the tissue integrity, which is referred to as
a "cut" or "needle stab" and in dire situations, tissue is actually
torn apart by explosion, impact, machinery accidents, etc. But,
there is another form of tissue damage that is similar to the
development of blisters that occurs when tissue has been
over-stressed and the outer covering may break. This results in
usually minor tissue damage, but can extend itself to a major
"sore" ischemic ulcer or "bedsore" if countermeasures are not
immediate.
[0009] Exacerbating this situation is the normal aging process and
deterioration of normal body functions. Upon aging, tissue is not
as viable as younger tissue. Sensory feedback, which carries
signals regarding tissue viability information back to our brain,
is no longer as rapid and there is the potential of tissue harm due
to the unawareness of tissue failure. Especially prone to this
situation are those with diabetes, spinal cord injuries, leprosy,
overdose, dementia and so on, as well as the elderly, whose tissue
no longer has the turgor to counteract minor inflictions on its
surface.
[0010] A person who is elderly or has some enervation and is
confined to bed for an extended period will have a propensity to
develop tissue trauma sores (ischemic ulcers, decubitus ulcers or
bedsores). Typically these sores appear over bony prominences where
forces arising from the weight of the body are concentrated and the
lack of movement leads to tissue destruction. (Those with normal
sensation and mobility become uncomfortable and move to a different
position, while those under anesthetics can't move). To avoid such
sores, some form of tissue pressure/shear interface should be
provided to reduce these forces to a value that the tissue can
tolerate.
[0011] To better understand why the tissue dies, a simple example
is to push a finger hard onto a flat surface. Immediately, pain can
be perceived. The tissue is being forced up the side of the finger
bone, under the outer tissue, and the tissue is "shearing" away
from the bone. Directly at the center of that finger bone is the
"peak" pressure with adjacent tissue being applied "average"
pressure. Again, the average pressure may thus be low and the peak
pressure very high and this is why "average" pressure readings
found in various products and interface pressure studies does not
give correct tissue interface pressure information for protection
of that tissue.
[0012] This peak pressure eliminates nutrient passage to the
stressed tissue area and the tissue dies when the load is
sustained. This peak pressure phenomena is also related directly to
comfort but average pressure is not, as reported in the article
"Body Support Testing and Rating" in Hospital Materiel Management
Quarterly, Volume 14, number 1, August 1992 by Aspen Publishers
wherein sixteen different configurations of mattresses were tested
and rated.
[0013] These tissue trauma forces may be adjusted in a number of
ways--i) by putting the load where the body can tolerate it, ii) by
attempting to control interface forces across the patient body
support surface, or iii) by moving the patient periodically before
tissue reaches an irreversible death situation.
[0014] There have been many efforts, as evidenced by patents
discussed below, to eliminate this problem by a means other than
nursing help, which has resulted in a plethora of equipment
claiming to reduce the incidence of so-called Pressure Ulcers, or
more correctly known as "Ischemic Ulcers," as they are caused by
factors other than just "pressure".
[0015] The magnitude of this problem can best be described as
"horrific." It is estimated that in 1989 1.7 million hospitalized
patients were afflicted with the above scenarios. The average cost
for each patient was $40,000 to repair and settlements in the
$250,000 range. Additionally, it is estimated that the United
States spends $7-$55 billion per year on this preventable problem,
while mortality rate for the afflicted patients is between 23 and
37%. About half of all patients over 70 years of age developing
these ulcers have a fourfold increase in the rate of death. More
expenses are hidden, e.g., when comparing patients with bedsores
(Ischemic Ulcers) to those without bedsores, the average length of
stay increased by a factor of five.
DESCRIPTION OF PRIOR ART
[0016] In recent years, inventors have approached this problem of
tissue breakdown prevention using two basic approaches for body
support, fluidic substance or polymeric foam. Each of these methods
encompasses many variations that have met with differing degrees of
success. Also of note and in most instances, cross-contamination or
dust mite prevention has not been considered as part of a
performance requirement until after-the-fact.
1. Fluidic Support
Water/Air. Making use of a shaped structure and air bladders was
proposed by Weinstein et al. in U.S. Pat. No. 3,456,270 wherein
water was the supporting medium and a lifting inflatable bladder
interface was used for raising patient for transfer.
[0017] Whitney in U.S. Pat. No. 3,802,004 changed a patient
immersion depth through unique bladder arrangements inflated by
air, without changing medium volume.
[0018] Hagopian in U.S. Pat. Nos. 5,072,468 and 5,068,935 describes
a special bed frame for ease of manufacture and the use of water as
the base medium with an air bladder on its upper surface to lower
or raise the patient, as in Reswick (later), with the added ability
to provide an inflated wedge for postural trunk control of the
patient.
[0019] These approaches also were an attempt to reduce "hammocking"
over bony prominences that tends to negate the efficacy of the
support medium. It should be noted that the modern waterbed is
comprised of water, a supporting envelope to "hammock" some one so
that they do not sink into the bed and appropriate baffling or
channeling for stability of the water.
[0020] Air. There are a number of ways in which air has been
compressed, blown or applied to support a patient. Hart in 1926 in
U.S. Pat. No. 1,772,310, described a technique of alternating the
fluidic support points on the body by controlling the time each
support point was to be activated, while limiting interface
pressure to an acceptable value. Hart also introduced a method of
patient turning in this same patent.
[0021] Whitney, in U.S. Pat. No. 3,148,391 used a modified method
of support that was compact and introduced temperature control of
interface as well as the alternating method of support.
[0022] Ford in U.S. Pat. No. 4,711,275 opted to inflate and deflate
arrays of air cells through independent air compressors to create
an alternating pressure support system.
[0023] Krouskop in U.S. Pat. No. 4,989,283 opted to control height
of the supporting bladders in his approach to body support by
measuring any changes in cell configuration through a
microprocessor using its input from internal bladder sensors to
control appropriate valving to pressure sources or exhausts to
maintain each bladder at some referenced height.
[0024] Others used lateral support tube shaping (Talley of the UK),
while others included an air loss to circumvent needle puncturing
problems (3M) with appropriate control mechanisms.
[0025] Air, as a fluidic support, has been proposed in many forms
for various purposes of body positioning. A surgical table is the
subject of Canadian Patent 1035000 by Carrier where individual
bladders of air are positioned to keep the bony prominences clear
of the table, while providing a fairly stable support as each
bladder is independently inflated to a desired pressure. All are
then covered by a forgiving cover.
[0026] Air cushion machines are quite effective in supporting a
large unforgiving body against a homogenous and somewhat stiff
undersurface; however, their use as a patient support medium is
impractical. Then again, if enclosed in a container of soft tough
and highly flexible material, air is much more suitable for patient
support if designed correctly to reduce hammocking.
[0027] Consequently, by using air in tubular or oval containers and
arranging appropriately within the bed frame, a mattress of air
tubes is a reasonable approach, depending on cross sectional area
of bladders and their positioning. Shaping these air tubes and
putting holes in them to circumvent accidental needle punctures and
with a pump sufficiently large to keep ahead of the leak rate, had
its merits.
[0028] Although Armstrong, U.S. Pat. No. 2,998,817, first developed
an inflatable massaging and "cooling" system, as time passed,
materials were developed that had built in leak rates suitable for
beds and, thus, the current Low-Air Loss mattress approach evolved
using so-called vapor-permeable materials. Such materials may
consist of 80 denier nylon, or thereabouts, backed with a material
of choice such as a film of urethane or vinyl.
[0029] Hess, U.S. Pat. No. 4,638,519, demonstrated use of shaped
bladders using such materials with appropriate individual bladder
control and methods of bladder attachments with air supplies while
Goode, U.S. Pat. No. 4,797,962, used the process of controlling
these air bladders in groups as a means of modifying support
pressure under portions of the body as others have done in the
aforementioned. (Some of these approaches have been prone to
collapse when the patient is in the sitting position in the bed,
and consequently exposing the coccyx and ischial tuberosities [sit
bones] to excess pressure and shear due to increased bladder
loading by the vertical component of the trunk.)
[0030] Some have attempted to reach suitable body support through
the use of foam on top of slats placed on top of air cylinders, as
outlined by Wilkinson, in U.S. Pat. No. 5,070,560.
[0031] High Density Fluid. Reswick, in U.S. Pat. No. 3,803,647,
used a mixture of Barium sulfate ore and water (or other fluids) as
a medium of support with a loose fitting lifting interface sheet as
the top member of the unit. This sheet was inflated and allowed
access to the patient at a suitable working height for the
attendant personnel. The aqueous solution of barites was used as
its specific gravity could be much greater than "1," and thus
support a body without immersion problems of water only. This
specific gravity, greater than "1", allowed the patient to lay in
the solution and be supported up the body sides to an optimum
immersion point. If the specific gravity is too high, excess
pressures can be exhibited as area of support is drastically
reduced. Keeping the mixture sufficiently fluidic presented a
maintenance problem that led to patient disuse.
[0032] Patent '647 also addressed shaping of the container to
reduce the contained mixture volume and of a tubular top bladder as
a stiffening method of the upper surface of contained fluid for
easier patient transfer or performing dressing changes.
[0033] Thompson, U.S. Pat. No. 4,357,722, demonstrates a flexible
open mesh approach in a special bed frame to support the patient
interfacing medium to change tension of support under various
portions of the body.
[0034] Hargest et al., U.S. Pat. Nos. 3,428,973 and 3,866,606, used
fluidized beads to create a specific gravity greater than "1".
These beads were micro-balloons approximating 100 microns in
diameter and were "fluidized" by an air plenum chamber placed at
the base of the beads separated by appropriate filtering and
restrained to remain adjacent to the patient by another optional
filter. Fluidization depends on the pressure drop across the
supporting beads and that of the filtering system. Excess drop
reduces fluidization, increases heat loss and can create ballooning
of upper cover. It is thus necessary to adjust pump flow to match
patient needs and size.
[0035] Lacoste, U.S. Pat. No. 4,481,686, controls bacteria through
bead selection.
[0036] Goodwin addresses support of beads in U.S. Pat. Nos.
4,564,965, 4,672,699 and 4,776,050, with sequential diffusion of
beads in U.S. Pat. No. 4,637,083.
[0037] Viard in U.S. Pat. No. 5,402,542 demonstrates use of a
programmable EPROM and heat exchanger to control bead system
component temperatures.
[0038] River sand has also been used in place of beads and
periodically "fluidized" with marginal success.
[0039] Yet another approach that may be considered somewhat fluidic
is the use of gel and air wherein a semi fluid gel is used in place
of the fluidic bead systems in much thinner beds than the units
discussed above. Due to the nature of the gel, however, its
accommodation of high forces is somewhat limited.
2. Use of Polymeric Foam Such as Polyurethane
[0040] Flat Stock. Polyurethane is formed through the mixing of
different polymers under controlled conditions. Some manufacturers
provide the fabricator with huge blocks of foam, which are then cut
into required sizes and sold to various fabricators of furniture,
mattresses and so on. Some of this stock is sold as-is, or as a
finished item when placed within some acceptable cover consistent
with industry requirements. Some foam is rigid and some
flexible.
[0041] Flexible foam acts somewhat like a spring. It is well known
that the further a spring is compressed the stronger is the
resisting force of that spring, and so it is with foam. The
unfortunate part of this foam as a support media is that the human
body is not flat and hips protrude further than waists.
Accordingly, when one is side lying on foam, the hip sees more
spring-back (foam fightback) or a higher load than the waist. The
hip bone (Trochanter) is poorly vascularized, and thus the tissue
at its surface can be robbed of the desired blood to keep the
tissue healthy. Thus, the enervated person is unaware of the damage
being incurred with this load, the tissue dies, and the result is a
sore where the skin integrity is forever damaged without surgical
intervention. Other parts of the human body, e.g., the posterior
heels, malleolus (ankles), iliac crest (pelvis), coccyx (tailbone),
ischial tuberosities (sit bones), scapula (shoulder blades),
occiput (back of head), elbows and ears are areas that are also
poorly vascularized and prone to breakdown with small loading of
tissue in these areas.
[0042] Those with normal sensation and mobility feel this excess
tissue load as a discomfort and responsively move away and thereby
restoring circulation in that region. It has been clinically noted
that a sleeping person will normally move more than twenty times
during an eight hour period on a so-called "standard mattress."
[0043] Thus, flat stock foam, using current technology, is not very
desirable for patients at-risk of tissue breakdown or for their
comfort. Some materials tend to give way with applied load as in
the case of materials used for the Apollo astronaut couches.
However, this material, known as "visco-elastic" foam, is
expensive, temperature sensitive, heavy, flaky, tends to tear
readily, and was not generally used by the bedding industry in the
past.
[0044] Flexible polyurethane foam has been the material of choice
recently. These materials are available in many densities and
Indention Force Deflections (IFD). Densities may range from the
soft 1.1 pounds/cubic foot to about 7 pounds/cubic foot and an IFD
range of about 14 to 180 is commonly used for bed support purposes.
These foams are generally manufactured as a polyether, polyester,
high resiliency or other foam, with all exhibiting different
characteristics. The polyether materials are generally found in
furniture, while the polyester is used in packaging requiring fire
resistance, while high resiliency may be found where continual
cycling is encountered. Other foams also include rubber and other
compounding, which have not found great favor in the
bedding/cushioning industry.
[0045] Although combinations of many of these foams is common
knowledge in the industry, polyether material is less expensive and
it may be found in products where replacement is no problem or
where material is not used extensively. Its durability under
continual loading has been less than desirable.
[0046] Cut or Shaped Foam Stock. Reducing forces encountered in
flat stock of polyurethane was obtained through reduction of a foam
support in the bony areas by cutting the foam in a special pattern,
known by the name of "surface technology", as proposed by Rogers
(the inventor herein) in U.S. Pat. Nos. 3,885,257, 3,866,252 and
4,042,987. Others also cut foam as disclosed in U.S. Pat. No.
3,828,378 by Flam, U.S. Pat. No. 4,901,387, by Luke and later U.S.
Pat. Nos. 5,025,519 and 5,252,278 by Span. Kraft in U.S. Pat. No.
4,679,266 simulated foam support by zones of inner (mattress)
springs with varying strengths.
[0047] Murphy in U.S. Pat. No. 4,628,557 and Rogers (inventor
herein) in U.S. Pat. Nos. 4,042,987 and 4,903,359 could make a
selection of foam removal under affected areas of the patient, and
in Rogers' case, overloaded adjacent support members rolled
automatically into the vacancy to spread load gradually to adjacent
areas.
[0048] Bony areas of the body can be free of all force in foam
products through use of material cutouts in mattresses, mattress
replacements, body conforming supports or cushions. However,
shearing forces at the demarcation edge of support and no support
are a harbinger of tissue death, unless that demarcation is gradual
and can be overcome by the body's internal blood pressure without
creating total occlusion of the blood supply. It is then of
paramount concern that proper shaping of the edges of regions where
foam is removed is built into any design of a support surface so
that loading is transferred gradually to adjacent support areas of
the body more amenable to the applied forces (putting the load
where the body can tolerate it). Some methods to do this are
disclosed in U.S. Pat. Nos. 5,127,119 and 5,048,137 by Rogers
(inventor herein). Foam is cut away from bony areas and edge or
shear effects are accommodated by cutting foam around the removed
foam area to create supporting foam forces "normal" to the body and
give a gradual buildup of load over a reasonable area where blood
flow is not compromised. One patent discloses technique of load
spreading through shaping of the cutout conically or approaching a
bell shape and consideration must also be given to packaging of
delicate instruments, fruit, etc.
[0049] Convoluted foam, initially used in anechoic chambers, is
formed from flat stock put through a convoluting machine, and has
been used as a mattress or pad where the patient is supported by a
number of peaks and valleys, such as described by Schulper, in U.S.
Pat. No. 3,197,357. This machine can produce two products 4'' thick
from one five inch piece of foam. Obviously, material is spread
equally between the two halves in such a manner as to create a peak
of four inches with valleys to offset the adjacent peaks, a type of
"mirror" image.
[0050] Peak sizes were varied, as well as depth of valleys, in an
attempt to equalize forces without complete relief of affected
areas. In some instances, manufacturers cut the peaks off some of
these convoluted pads in an attempt to control support load
distribution in a more acceptable product, as the peaks were of
little support value and foam was wasted. Most of this type
material was fabricated from inexpensive foam and has been banned
from use in many medical facilities across the U.S. This is because
of its inability to eliminate damaging forces on body tissue when
the user had expected more protection than the material could
provide without extensive forming, cutting or having its
performance completely modified as disclosed in the subject
patent.
[0051] It should be noted that the so-called "visco foam" designed
for NASA and being more aggressively marketed now, can be
significantly improved with the present invention as its
spring-back can be eliminated on demand by the user. Water beds, on
the other hand, must have sufficient strength in their membrane to
hold a person out of the water (and thus create pressure points)
with the membrane, else the user would sink to the bottom because
of most body's greater than 1.0 specific gravity .
[0052] Replacing water with "oil-well" drilling MUD, with a
specific gravity of 2, was proposed by Dr. J. Reswick. This would
allow a person to actually float, and if a soft interfacing
material was used to separate the user from the MUD, pressures were
optimal. However, the concept proved to be impracticable to
institute for various reasons, one being that the MUD was a severe
handling problem during shipping, and weight was another.
SUMMARY OF THE PRIOR ART
[0053] From the foregoing, it is clear that many different
approaches have been used in an attempt to reduce discomfort and
injury in a bedridden patient. Such discomfort and possible injury
is a direct result of the stress concentration created by the
non-uniform shape of the human body. An ideal supporting structure
would distribute the forces due to the body weight in a way to
minimize or eliminate any localized concentrations of stress,
particularly shear, such as would occur at a discontinuity in the
underlying material. Fluids, gels, air and such may give an overall
uniform support. However, as shown in U.S. Air Force studies, even
this approach gives discomfort to the seated person as interface
pressures exceed the popular interface pressures of 32 mmHg and
portend of potential tissue trauma.
[0054] Where bony structure in the body is near the surface and not
protected by a reasonable thickness of soft tissue, an effort
should be made to greatly reduce or even to eliminate the stress in
that region, compensating by slightly higher forces elsewhere,
where the body can tolerate it. Total elimination of stress locally
is particularly important to promote healing where a bedsore or
injury already exists so that the affected site can be readily
supplied with a healthy flow of blood. This same rationale applies
for all sites of the body where blood flow may be compromised by an
inappropriate body support medium, such as would occur at not only
the discontinuity of the inner support material within the mattress
or cushion say, but also that major consideration always overlooked
in the past, the material between the inner material and the actual
tissue of the body being supported. This may come in the form of
"fire barrier" material or the actual outer covering of the inner
material normally ascribed to as the "mattress cover". If this
interface material is unforgiving in the worst case, all of the
inner core characteristics can be masked to such an extent as to
completely negate the efforts given by surface technology shaping
and such. In this case, each component may perform well on its own
but lacks the conformance needed to optimally perform in concert
with other components and protect tissue as initially intended.
However, with correct design of singular items, the correct
symmetry can be attained to perform as needed collectively. This
requires consideration of not only the immediate support medium but
also the major support structure, such as type of chair, spring or
stainless steel sheet bed and such.
[0055] Similarly, packaging of complexly-shaped products to be
shipped from one location to another has created a special
marketplace for special support media, such as "foam-in-place", air
cells and so on. The present invention addresses this need as well
because the packaging of people is no different to packaging
components or products--its a matter of degree, as all must be
protected from the outside environment where their integrity is
challenged. Another reason for including this aspect of protection
is to conserve use of oil and forest-related products and help keep
the economy in check as the proposed interface protection media can
be re-used for reshipping over and over again and the proposed
mattress and seat cushions keep much of the environment away from
the foam and thus extend its life substantially.
[0056] The prior art has not as a rule directly addressed these
goals. Although it has been generally recognized that a support
structure for the human body needs to provide different stress
patterns in different areas, as do delicate instruments, most
schemes do not fully achieve it. In fact, some have discontinuities
in material and make no apparent attempt to minimize shear stress
at those points. Again, similar to the packaging of products such
as glassware, arriving at a destination, broken.
SUMMARY OF THE INVENTION
[0057] This invention relates to the support of a person in the
prone, supine, side-lying, semi reclined or sitting position
without the usual stress concentrations that may lead to tissue
trauma, decubitus ulcers, ischemic ulcers, or bed sores, and is
extended in its concepts to the shipping needs of delicate
instruments (positioning, cushioning and impact protection) and
other items of concern. It is also an object of the present
invention to provide support for a human body in a manner so that
the forces of support have fewer concentration points which are
likely to occur at or near bony prominences, nerves or tendons and
which, if not accommodated, can lead to serious complications, such
as ulcers, nerve damage or strained muscles, tendons and other
disabling factors.
[0058] This invention addresses the stress distribution problem by
combining several techniques. First, using a basic foam inner
material, or other material that gives a similar performance, the
invention provides regions where material has been cut in some
selected manner, placed adjacent or in concert with dissimilar
material, or the same material with differing support
characteristics, cut away, omitted, or formed to reduce the
magnitude and abruptness of any stress concentrations when
supporting a body (collectively or alternatively: "foam force
accommodation zones"). This technique is then combined with the
process of applying a membrane ("enclosure member") of appropriate
warp and weft to assure appropriate force distribution is applied
to the supported surface should cavities be located under the
membrane and over the insert material to smooth out the localized
variation in stress and concomitantly, if the membrane is able to
control the amount of air or fluid surrounding the space between
the bladder and interstices of the foam, the fluid pressure may be
varied to change the characteristics of the foam itself.
[0059] This latter components or aspect of the invention can be
characterized by reviewing U.S. Pat. Nos. 5,127,119 and 5,048,137
by the present inventor and observing that when the described foam
structures were loaded by a body, the foam will "fold" over in a
normal direction to the tissue of the body to reduce the shearing
occurring at the tissue. (By looking at a cross-section of the
conical shape as discussed herein, a linearized "back-sloping"
across a surface edge has a much more efficient pressure/shear
distribution than the so-called "waterfall" cut.)
[0060] Notably, if a bladder were to be placed between the body and
supporting foam of the nature just described, the bladder, with air
or fluid control ability, can hold the foam (of the linearized cone
edge) in its desired place and virtually create a minimal interface
differential force, much as is found when floating in water.
[0061] By considering all the requirements for patient care ranging
from personal hygiene to "chucks," to diapers to sheets, to
mattress covering to sweat collectors, to fire barriers to support
medium, to the underlying support, the present invention has
evolved to give the patient protection as well as comfort.
"Comfort" has been shown to be directly related to forces exerted
on the body by Rogers, as previously mentioned in the "Hospital
Materiel Management Quarterly" article, "Body Support Testing and
Rating," dated August 1992.
[0062] Many inventors and developers of products have been diligent
in their detailed design of products, as seen from within the
confines of a designer's view without the clinical experience seen
by the inventor (substantiated by reports from University of
Southern California School of Rehabilitation Engineering Center at
Rancho Los Amigos Hospital (California) Annual Reports of progress,
CV Mosby Orthopedic Atlas, and being Director of the U.S. Army
Field Medical Laboratory fabrication and numerous technical
articles) to adequately formulate a suitable set of specifications
gained from experience in the clinical care of patients as well as
in the design of delicate instrument shipment, such as those
encountered in a U.S. Army Field Medical Laboratory. With this
background, the present inventor hereof expands on the objectives
of this invention to include patients' well-being, as well as
handling of delicate equipment and as such, emphasizing that a
major objective of the invention is to improve on the many
available products, followed by details of collective
specifications of previous patents, mingled with personal
experience and coalesced into new "Definitive" mattresses,
upgrading of past patents and designs, cushions and the supporting
structures for handling delicate products.
[0063] In view of the foregoing, it is an object of the present
invention to provide an improved mattress enclosed in a functional
membrane.
[0064] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
upgrades existing equipment performances to better meet the needs
of consumers and patients
[0065] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
can be used for patient support, tissue protection and comfort
whether seated or laying down.
[0066] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
clears the sacrum, coccyx and ischial tuberosities of pressure and
shear when required by raising the supported person sufficiently to
clear pressure points on their body.
[0067] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
also incorporates alarms, if so needed, to indicate when tissue is
being overstressed through built-in sensors.
[0068] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
has nearly zero interface pressure/shear over the potentially
affected site.
[0069] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
extends the life of the contained foam within a support system by
isolation from the local environment.
[0070] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
allows easy storage and shipping with its self-contained pumps able
to be vacuum packed without external pumps or the like.
[0071] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
can cost-efficiently cover existing mattresses/cushions with
portions of the present invention for low cost upgrading of
equipment and service cost reduction.
[0072] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
can control time constants and damping ability of foams, springs of
all shapes in spring mattresses and seating to meet the goals of
the original designs through compression and expansion of fluid
medium surrounding portions, or all of the existing equipment.
[0073] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
can assess tissue loading by measuring pressure and shear under the
bony prominences without any additional equipment to the mattress
or cushion which, in turn, will allow one to take the corrective
action with built-in features of the existing equipment.
[0074] It is another object of the present invention to provide an
improved mattress enclosed in a functional membrane that only
requires one person to readily move a patient via the built-in
transfer sheet.
[0075] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
also correctly positions patients with self contouring body
supports.
[0076] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane with
the ability to self vacuum pack the position of patient or when
being transported from one location to another.
[0077] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
gives the user even more fluid-like support through use of
judicious control of fluid surrounding this foam mattress or
cushion by use of an enclosed cover and suitable operating means to
control the internal environment.
[0078] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
can complete foam return by scaling closure of a twist valve marked
for time constants or rates of response.
[0079] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
includes the option of time constant changes, or the direction of
flow to and/or from the mattress at a controlled rate or all by
valve control at user option.
[0080] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
can vacate or inflate the present invention through twist valves in
tandem or unitarily.
[0081] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
allows the user selection of one, three or five valves, joined
integrally with the supported member to improve overall performance
needs.
[0082] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
allows the use a remote plug-in attachment integral to the support
surface.
[0083] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
uses an outside source of energy to operate its functions.
[0084] It is another object of the present invention to provide an
improved mattress or cushion enclosed in a functional membrane that
can be controlled remotely through suitable RF or RF-like
coupling.
[0085] It is another object of the present invention to provide an
improved mattress, cushion, packaging enclosed in a functional
membrane that can also be used as partial reusable packaging around
a product that can perform well with varying time constants tied to
springs for buffering at required frequency of vibrations expected
during transit.
[0086] It is another object of the present invention to provide an
improved mattress or seating enclosed in a functional membrane that
can provide a seated driver or passenger in a vehicle with a
variable time constant support, much as the variable dampers are
tied to the chassis of a vehicle to assist in smoothing out the
chassis vibrations encountered over various terrains.
[0087] In satisfaction of these and related objectives, the present
invention overcomes the stress distribution problem unlike anything
available by combining several techniques. A basic foam inner
material is specially cut to reduce the magnitude and abruptness of
any stress concentrations when supporting a body. A membrane of
appropriate warp and weft is applied to the supported surface to
smooth out the localized variation in stress while the fluid
pressure may be varied to change the characteristics of the foam
itself and the under-support structure designed to assist in
meeting these ends.
BRIEF DESCRIPTION OF THE DRAWINGS
[0088] FIG. 1 illustrates the concepts of tissue trauma or tissue
death.
[0089] FIG. 2 is a detailed description of drawings for design of a
cutout.
[0090] FIG. 3 illustrates the function of a simplistic approach to
a difficult problem--care of the hospitalized, elderly or
bed-ridden patient.
[0091] FIG. 4 illustrates cavity function with loading and vacuum
control.
[0092] FIG. 5 illustrates the pressure/shear transducer.
[0093] FIG. 6 illustrates three versions of the invention for
general use with mattresses, cushions and shipping fragile goods
with a reusable cover or "shipper."
[0094] FIG. 7 illustrates a detailed operation of the
self-contained pump action.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0095] Referring to FIG. 1, the concepts of tissue trauma or tissue
death is illustrated. Foam compression has a varying, and often
times subjective result to people as an identical compression or
cushioning feels "hard" to some and is acceptable to others.
Mattresses or cushion are generally accepted by "feel," which
relates to peak pressures as illustrated in FIG. 1.
[0096] Part (a) illustrates a slab of foam (1). Part (b) shows a
body (2) loading foam (1) to a height of (3). Part (c) shows a
heavier body placed upon the same foam which compresses to where
equilibrium has been reached. However, in part (d), with a heavier,
load there is only a thickness (5), depicting a possibility of
"bottoming-out". This term may be a misnomer, as the foam may not
have bottomed out as it could have been compressed a small amount
more before all elasticity of the foam has disappeared and only the
physical cell mass is supporting the load (2). Part (e) illustrates
a bony body (6) being placed upon a similar foam block (1) and the
resulting forces are (7) where the bone (9) is penetrating the
tissue and causing shear forces (8) up the side of the bone. This
force can be shown to be the directly related to the peak pressure
(12), while the additional shear load at the tissue surface (11)
and the surface tension (10) also contribute as shown in the next
part. Part (f) depicts the breakdown of tissue at the surface (13)
but the majority of damage is at the bone demonstrated by (14).
[0097] These are the forces that restrict blood flow and are the
start of the insidious ischemic ulceration previously discussed.
One of the primary objectives of the present invention is to
prevent these causes of tissue failure.
[0098] Referring to FIG. 2, which is a detailed description of
drawings for design of a cutout. In FIG. 1, the effect of sharp
edges or difference between support and no support results in high
shear forces to a body. In FIG. 2, the body is placed over a shaped
cutout which can be a cone in cross section or a straight edge into
the drawing. When the edges (3) of the foam (1) and a cutout (2)
are loaded by a body, the edges roll inward as at (4). This gives
more surface area of support so the load at (4) is spread over a
greater area than if the walls of the cutout were straight (greater
area for load, the less pressure at the site of support), or even
cut inward and the forces tend to be normal to the cutout at (4).
This, in turn, reduces shear at the bone and the perpendicular or
peak pressure loading (5) is also reduced creating a safer
environment of force control and also resultant comfort.
[0099] FIG. 3 illustrates function of a simplistic approach to a
difficult problem--care of the hospitalized, elderly or bed-ridden
patient. The shaped cone of the inventor's prior patent has led to
the use of the sloping backward method of edge control of shear
forces on the body adjacent to the coccyx/Trochanter areas of
support in a mattress, cushion and sensitive areas of body
support.
[0100] A person's trunk section 1 is shown placed on the support
27. 2 is the leg section and it also is placed on the support 27,
which may consist of strong corrugated cardboard for low costing
that can consist of two adjacent panels which are bifurcated
longitudinally to allow rolling of the supported mattress or
cushion or in the case of the mattress, allow "gatching" of the bed
(and supported mattress) while giving the back support, clearing
the coccyx and ischial tuberosities of the patient and allowing
positioning of the legs independently. 3 is the foot pillow
attached by hinge 28 to the main cover of Dartex like material also
used over 2 as in 1. 4 is the outer edge material as is 15 with a
cavity in between and below, to support the use of the collector 24
fitting within the sloping cavity between the two names sections. 5
is the rolled or folded transfer sheet attached to the cover 7 and
the leg covering. This sheet is folded back onto itself for the
patient to be rolled upon and when in place, sheet is pulled along
with the patient for transfer to wheelchair etc. 6 is a sensor
shown in following figure. This sensor can be built into the cover
or be separate item. 7 is outer fluid proof material that is vapor
permeable (thus the need for the sweat collector introduced through
the double Ziploc type fastener) that allows moisture to enter the
inside foam if not protected. Material is RF welded on all edges to
assure fluid proof integrity. 8 is the self-inflating pillow
attached by hinging to the cover material. The pillow covering will
also be similar to the main cover except more flexible. The pillow
will be filled with particulate material of choice so that it can
also be vacuum controlled, fluid inflated or time restrained
compression to meet patient/ physician needs. 9 is the hinge
attachment to the cover. 10 is the valving discussed under the
self-inflating description in following. 11 is the pillow deflated
and positioned over end of bedding. 12 is the vent control section
of the pillow described in the following also. 13 is the inflated
pillow. 14 is already covered. 15 is the end filler of the cavity
between the head and leg portion of the support system. 16
illustrates the back-sloping edge of the cutout running laterally
across the mattress for pressure/shear relief of the Trochanter-
coccyx-sacral area of the body fitting over cavity 30. 17 are
valves for controlling the positioning and function of the rotated
foot piece 21 hinged at 28 and now used for knee resting shown
dotted. 18 is the pillow-leg portion in the knee support position.
19 are valves as in previous sections to control the time constant,
vacuum forming or inflating ability of the various portions of the
Definitive mattress. 20 shows the same unit pushed up in place and
held there by the hinge 28 and particulate material fluid vacated
to form unit to feet if needed. 21 is foot pillow position for
normal foot control as needed. 22 notes the valve positioning. In
smaller units one set of valves will be quite adequate although all
will perform well when appropriately designed to match production
needs. 23 is hinge point in base unit if it is hard material and
will not flex on its own. 24 is collector of waste material that
can be removed from under patient when appropriate. 25 is a self
inflating pillow for positioning collector or it can have added
feature of filling the vacant space 30 if collector not used. 26 is
pneumatic sensor for measuring peak pressure/shear in a novel
inexpensive way described later. 27 is the composite baseboard
previously mentioned. With patient in place on the Definitive
mattress the buttock portion of the body will be free of support
due to the cavity 30 in which the collector is placed. 28 is hinged
portion of pillow 3. 29 is another Ziploc for placement of
stiffener to assure the vacuum aspect pulls down under the patient
rather than allow vacuum to also raise bottom of cavity unless this
aspect is used to raise collector 24 and pull down covers over
modules 1 and 2 when jointly connected through pillow 25 or over
baseboard 27. See following figures for this detail of action. 30
is the cavity over which the buttock portion of a person is placed
and in which area the effluent is caught by collector 24. It
becomes obvious that the catch area of this cavity is also the bony
area of the body more prone to tissue death if overstressed.
[0101] The mattress can be pneumatically controlled by valves at 22
to any degree needed by patient. More vacuum and the more the edges
at 26 will fold into the cavity giving more relief or used to
reduce back pain in some.
[0102] The head can be elevated rotated and controlled with
softness dictated by inflation level of unit. The knees can be
elevated through use of the rotating foot/leg unit and molded to
the body shape require while unit is pumped on the side. If the
unit is to be stored or shipped, it can be folded back on itself,
both sections vacuumed by their self-contained units and unit
moved.
[0103] FIG. 4--Cavity function with loading and vacuum control. As
previously illustrated, the back cut top edges of the foam cavity
are initially in position 1 when unloaded and cover 4 spans the
gap. When a load W is placed on the cover and cavity the foam rolls
down to position 2 with the cover also being forced down into the
cavity. However, when a vacuum is applied to space 7 and the
surrounding foam, the foam and cover 4 is now pulled down into
position 5 creating a gap 6 under the loaded site. This is where it
is feasible to have zero interface pressure under a bony site, such
as a trochanter and the shear forces are now spread over the gently
curved area of the foam without the foam spring force in place.
Thus, this creates a pseudo fluidic type of support at the tissue
interface.
[0104] FIG. 5--Pressure / shear transducer. The unit illustrated is
an integral part of the Definitive mattress where indicated for
patients with potentially compromised tissue. As a stand-alone
unit, it consists of two layers of highly flexible fluid-proofed
material with little or none surface "stiction". In its preferred
embodiment, the unit is RF welded in the form shown with the outer
envelope 1 and the internal divisions 2 creating a maze type of
path to be placed under a suspected site of concern on a patient's
body.
[0105] Air is introduced in preferably "burst" manner or step
function. When air is noted coming out of the unit the amount of
air applied at the inlet for this to happen gives the interface
forces under which the unit is being subjected.
[0106] Calibration of the unit requires demarcation between
pressure and shear by using standard weights to close off one part
of the maze. It is obvious to those skilled in the art of air flow
to see that if the unit is highly flexible it will see not only the
pressure involved but also the shear occurring at the site of
monitoring. This is unattainable with standard sensors with
discrete elements tied together as the measurements in this
instance are clouded by sensor placement relative to each other,
flexibility of carrier and potential cross-talk between
sensors.
[0107] The sensor of the present invention is unique because of its
minimal expense as an individual sensor, but also because of its
suitability to be included in the covering of product without
affecting product performance. The air supply, switching and
monitoring gauges are omitted as they are common to those involved
in instrumentation methods.
[0108] The transducer can be part of the cover design as its
interference with system function is minimal and its usefulness far
outweighs any loss of motion to the covering. Monitoring can be by
RF link to a station or to attendant or by a simplistic visual
indicator that is hand held or part of the bed. In the preferred
embodiment, automatic sequencing of air bursts can be
self-contained in a hand held or remotely located unit in a number
of ways commonly known to those who design such devices.
[0109] FIG. 6--"Fits-all" covers. FIG. 6 illustrates three versions
of the invention for general use with mattresses, cushions and
shipping fragile goods with a reusable cover or "shipper."
Illustration A is for covering existing mattresses to make them
more functional and without having to replace existing mattresses
because the cover is ripped, torn or unusable or the mattress
itself can have upgraded performance in preventing tissue trauma or
improving comfort of the user.
[0110] Liners of foam can be placed inside or be added while
inserting mattress. 1 depicts the foot section as discussed in
foregoing. With its hinge to cover 5 if needed for particular
application of foot drop, cavity filling a foot handling as in the
Definitive unit of FIG. 3 or knee elevation. 2 is Ziploc for
mattress insertion. Fitting a mattress into a cover can be
problematic. However, the subject invention cover herein being
discussed is not necessarily a standard cover, as it can be
oversized and surplus (minimum) tucked under assembled item. 3 is
pillow with its hinge to 5 and 4 are the controls with functions as
outlined in previous disclosures herein. The unit is highly
flexible and shipping and handling are satisfactory as all air can
be vacated by using outside pressure on package and closing the
metering valve. "B" is similar to "A" with the control remote as
discussed previously. "C" is the cushion and packaging module sized
as needed with Ziploc probably on underside for the seat
cushion.
[0111] It should be noted that the Ziploc type structure must be
fluid proof under pressure differential or it will not be suitable
for vacuum of any extent before its feature is negated.
[0112] For cushion use the unit should be sized appropriately as
tucking excess on underside may be suitable for a mattress but
problematic for commercial or office use. When the unit is made in
factory with sizes established the completed item may be welded in
place for function and appearance. Ziploc length and positioning is
critical for easy assembly or additional filler will be provided as
an extra for appearance.
[0113] Pumping elements needed can be by specification. If no
pumping-up is needed, then one function can be omitted and only
three valves used or at minimum two. Packaging units are fabricated
much like a Ziploc itself or one of the items marketed for storage
of clothing. However, this unit has a self contained pump and vent
as well as added air if necessary for additional impact
protection.
[0114] Cushions can be assembled to be controlled by the same
process as the mattress described. The user can deflate/inflate by
compressing any part of the cushion with valving appropriate to
need activated as discussed in the following explanation of pump
operation. A sensor can be included when bottoming is about to
occur if a cutout is used. The client then replaces the cushion
after emergency inflation. A timer function can also be included
with a pneumatic option to assure time of sitting has expired.
[0115] As for positioning and support products, as previously
mentioned, all the separate units now in use can be made more
effective in function, extend their life and reduce costs by
including appropriate valving and sloping of support surfaces at
areas of concern to include consideration of design with all or
part of the invention as needed to include those to be considered
as a minimum head, body, arm, leg and foot positioners (with safer
support), operating room table pads, gurney pads, wheelchair
inserts, wheelchair cushions and pillows.
[0116] FIG. 7--detailed operation of the self-contained pump
action. The top figure for the self-contained pump concept
illustrates a typical concept for the self pumping of fluid in, out
and metered. #1 is outer fluid-impermeable bladder or cover for
enclosed mattress/cushion/other #4. #2 is self-inflating inner
bladder adjacent #4. #3 is second self-inflating bladder adjacent
#4. #4 is main mattress that could be plain foam, textured foam,
convoluted foam, batting, sliced/diced foam, surface technology
applied to foam surface performance, contoured shapes, irregular
shapes of varying densities (spring-back) and demarcations, springs
(flat, coiled, conical and such) other fluidic components in
various shapes for demarcation control. #5 is metering twist valve
(or other able to adjustably meter flow) for altering #4 response
time and spring constant by modifying flow through cavity #12 and
surrounding areas and interstices of #4. #6 is twist valve (or
other to be able to finitely control fluid flow) is for metering
and controlling flow out through its related one-way valve #8, its
self contained foam cavity surrounding #2 with its enclosing fluid
impermeable membrane with fluid entering one way valve #10 for
control of egress of fluid #12 from around and through #4 and
exiting at one way valve #8 and metering twist valve #6. This
action evacuates fluid from within enclosure #1 and
mattress/cushion #4 by compressing combined unit at position #12
above #2 & #3 with #5 and #7 closed. This allows the attendant
or user to adjust amount of fluid that is vacated around #4 to such
an extent that fight-back of #4 is removed or actually overcome to
extent of compressing #4 in its entirety. # 7 is a metering twist
valve (or other able to adjustably meter flow) allowing air to
enter its associated one-way valve #9 through foam #3 and exiting
through one way valve #11 to cavity #12 with #5 & #6 closed.
This allows the fluid to enter by the amount needed by user to give
a combined inner control plus its surrounding fluid to reach a
level of comfort or height needed for various reasons.
[0117] In summary, close valve numbers 6&7 and use Valve #1 to
change inner component #4 to respond as rapidly or as slowly as
needed by user. Close #5 & #7 and open #6 to expel contained
fluid #12 to compress around #4 and where #4 has been contoured or
cut in some manner to give a varying force support topography, the
weaker sections will collapse first so that absolute clearance of a
supported body, be they seated or laying down, can be obtained
through pumping the foam located in an unused portion of the
support surface such as the corner of a mattress or cushion (Note
the unit may be mounted sideways for cushion or other action if top
compression is not suitable.) Closing #'s 5 & 6 and opening #7
allows fluid to enter the enclosed structure and pumped in a
similar manner as when evacuating, will allow fluid to enter at a
rate and amount suitable to the user who may wish to have the
fluidic feel to their support or allow person to raise themselves
to a different working level for comfort or function.
[0118] The lower figure of FIG. 7 illustrates one method of
remotely controlling the function described above to be removed
from the actual support surface. The following describes one method
of direct physical linking to the surface to be controlled but it
can be readily understood that such functions can be duplicated
through an RF type of interconnect to self contained units mounted
suitably around, or in, a surface requiring control as described
herein. It is also another method wherein Hospital air vacuum and
pressure sources could be connected directly with associated
circuitry to remotely control bed/mattress/wheelchair surface
support functions. The unit #9 can contain its own pumping section,
as described in previous figures where valves # 1, 2, 3, 4 and 5
replace #5, 6, 7, 8, and 9 with valves 10 and 11 selectively placed
in portable unit or in the unit under control, or where vacancy #12
occurs. #6 & #7 are self priming pumps as previously described
with tubing such as #8 collectively operating through #10 on to
quick disconnect #11 attached to the body under control.
[0119] Although the invention has been described with reference to
specific embodiments, this description is not meant to be construed
in a limited sense. Various modifications of the disclosed
embodiments, as well as alternative embodiments of the inventions
will become apparent to persons skilled in the art upon the
reference to the description of the invention. It is, therefore,
contemplated that the appended claims will cover such modifications
that fall within the scope of the invention.
* * * * *