Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
This invention relates to surgical dressings, and more
particularly to a controlled pressure surgical dressing utilizing
an absorbent batt of deregistered crimped tow, and a method of
making same.
Conventional wound dressings in the form of sponges and
the like can generally be divided into four major types or
categories.
Plain gauze dressings are generally transfer types of
dressing used either directly on a wound, or indirectly over
a non-adherent dressing. The primary function of this type
dressing is to lift and transfer the blood and other wound
exudates from the wound into a fluid holding reservoir, such
as an abdominal pad.
~ ashed gauze dressings are used where a softer, more
open mesh, bulkier sponge might be needed for transfer. Such
dressings have been made to provide a sponge structure that,
when applied, supplies some gentle pressure and better cushioning
than unwashed gauze sponges, however, inherently the structure
is not uniform in thickness and several plies have to be utilized
to provide optimal pressure. Additionally, while the washed
gauze dressing is more absorbent than an 8 ply or 12 ply plain
gauze sponge, the structure has limited absorbency when com-
pared to a 16 ply plain gauze sponge on a weight to weight
comparison.
Another type of dressing in use today is a filled gauze
sponge, which consists of one or two plies of unwashed gauze,
an inner matrix of cotton or rayon fibers, and in some cases
a layer of creped cellulose wadding used as an inner carrier.
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This type of dressing can be utilized as a small fluid reservoir
for soaking up and holding limited amounts of exudate. It
lacks the softness and bulk, and the ability to transfer
exudates in the same amounts that can be achieved with washed
gauze.
Finally, another type of sponge or dressing being used
today is similar to the filled gauze sponge with the only
difference being the replacement of the gauze cover with a non-
woven material. Dressings of this type have characteristics
similar to filled gauze sponges, but have additional deficiencies,
for example, the structure has decreased strength when wet as
compared to gauze, and the existence of a chemical binder in
nonwoven materials can be potentially irritating to some
patient~.
As described above, each of the four general types of
dressings used today has its limits in function due to the
design and construction, as well as the materials used therein.
Optimally, the most desirable dressing would be one that
incorporates as many of the positive characteristics as possible,
while elminating or reducing as many negative features described
above as possible.
Accordingly, it is an object of this invention to produce
a surgical dressing that has the absorbency and take up of a
filled gauze or a filled nonwoven surgical sponge, and the
softness, conformability and wicking ability of a washed gauze
dressing.
It is another object of the present invention to produce
a lofty, porous and soft dressing that supplies controlled
light pressure along the patient-dressing interface when applied
to a wound to provide support thereto.
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It is a further object of this invention to provide a
dressing that is porous enough to provide adequate aeration to a
wound, while still yielding a most positive cushioning effect
thereto.
It is still another object of the instant invention to pro-
vide an absorbent batt material that is relatively inexpensive
when compared to the price of today's raw materials.
A surgical dressing is formed by cutting a section of washed
gauze two to six plies thick so as to be two to three times the
length of an absorbent batt or matrix to be placed therein. The
absorbent batt advantageously consists of a portion or section of
deregistered crimped tow, such as crimped acetate tow, and is
positioned approximately in the center of the cut section of the
washed gauze. The raw edges of the cut section of the gauze are
then folded lengthwise over on themselves, completely covering
the absorbent batt. The selvage edge can then be folded over
upon itself so as to form a compact square or rectangle, the
selvage folds then acting as a set of opneable wings or tabs
which can be used to anchor the dressing in place over a wound
and supply a noticeable, yet controllable pressure on the wound.
The resultant novel structure produces a lofty, high bulk, porous
and extremely soft surgical dressing that provides good aeration
to a wound, while still yieldin~ a most positive cushioning
effect thereto.
In accordance with this invention there is provided a lofty,
porous, soft surgical dressing capable of supplying a controlled
pressure to a w~und comprising: a portion of washed gauze material
having a plurality of superimposed plies therein; and a batt of
deregistered permanently crimped tow positioned substantially in
the middle of said washed gauze material and being smaller than
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said washed gauze material, said deregistered crimped tow being
completely covered by lengthwise folds of said gauze material.
Figure 1 is a plan view of the surgical dressing of this
invention, prior to any folds having been made therein;
Figure 2 is a perspective view of the dressing of this
invention, having a fold made therein;
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Figure 3 is a perspective view of the completed dressing
of the invention;
Figure 4 shows a sectional view of an alternate absorbent
matrix that can be used in this invention; and
Figure 5 is a plan view of another embodiment of the
dressing described in this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
. .
A controlled pressure dressing is a novel concept in the
functional wound dressing area. It provides the absorbency
and capillarity of a filled gauze or filled nonwoven sponge
along with the softness, conformability and wicking ability
of a washed gauze dressing.
This dressing can best be described by referring to the
drawings in which Figures 1-3 show a portion of washed gauze 11,
having a thickness of two to six plies, preferably three plies,
which has been cut to be two to three times the length of an
absorbent batt or matrix 12 that is to be positioned substan-
tially in the middle thereof.
The absorbent batt 12 is a section of deregistered per-
manently crimped tow of either a synthetic or natural fiber.The tow can advantageously be an acetate tow and can be deregis-
tered in three dimensions by any process known to those skilled
in the art. The deregistering process greatly enhances the
fiber freedom of the individual filaments therein and thus
induces a superior bulk and advantageously produces a more
absorbent batt. The material selected must only have been
initially crimped and then deregistered in order to produce
the absorbency desired. Tow, rather than staple fiber,
should be used to avoid the possibility o~ fiber ends breaking
off and protruding into the wound, thuS eliminating a potential
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source of wound contamination. In the prior art, staple
fiber, rather than tow, has been routinely used in filled
sponges.
The washed gauze 11, having the absorbent batt 12 thusly
positioned therein can be folded in the following manner:
the raw edges 15 and 16 are folded lengthwise over each other
along dotted lines a a' and b b' respectively, to show the
structure of Figure 2. The selvage edges 13 and 14 of the
washed gauze then form a pair of openable wings or tabs,
such as at 21, that can be folded widthwise over each other
along dotted lines c c' and d d' so as to form a compact
surgical dressing. The openable tabs 21 formed at the outer
extremitiès of the gauze 11 on either side of the deregistered
tow 12 can be used to anchor the dressing in place over a
wound and to provide a controllable pressure on the wound by
way of the dressing.
The use of deregistered permanently crimped tow as the
absorbent batt has been bound to be particularly advantageous
for a number of reasons, not the least of which are, that when
crimped tow is deregistered it tries to retain its volume
displacement; that permanently set crimped tow won't collapse,
so therefore, a dressing utilizing same will have a cushioning
effect; and, further, that moisture won't collapse deregistered
tow making the material all the more desirable.
A preferred washed gauze material can be obtained by using
the process set forth in U.S. 2,081,370 to Secrist, of common
assignee, which describes a hot water bulking treatment to a
single-ply of open-meshed gauze fabrics. The fabric of
U.S. 2,081,370 is characterized by the presence in the fabric
of a multiplicity of crunodal loops, where yarns curve up or
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down out of the plane of the fabric, form a complete loop,
and then continue their path in their original direction.
A plurality of plies of this material can be used for this
invention up to six plies, three plies being preferable as
stated above.
In order to enhance the spreading of fluid into the
deregistered tow, one or more plies of absorbent crepe
cellulose wadding, or the like, may be wrapped around the
tow as shown in Figure 4 wherein the tow is shown as 31, and
the crepe cellulose wadding is 32. As shown therein, the
crepe cellulose wadding 32 is wrapped completely around the
tow 31 of the deregistered acetate so as to very quickly
spread any fluids thereon into the tow. While crepe cellulose
wadding is desirable for these purposes, any absorbent material
can be used so long as it is capable of taking up and spreading
fluids therethrough. Ideally, the absorbent crepe cellulose
wadding is cut to width equal to the width of the deregistered
tow and long enDugh to at least wrap same completely around
the tow material.
An alternate embodiment for the dressing of this invention
is shown in Figure 5, wherein essentially the same construction
is used. However, in this embodiment, the deregistered tow
matrix 42 has a substantially rectangular configuration and the
raw edges 45 and 46 of the washed gauze material 41 are folded
over onto each other along dotted lines a a' and b b' to form
a more elongated dressing than shown in Figure 2. The thusly
folded dressing also provides openable wings or tabs on either
side of the deregistered tow that act as anchoring points for
securing this type dressing to such areas as the perineum,
rectum/anus and the axilla. The wings or tabs thusly formed
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can then be folded over toward themselves as along dotted
lin~s c c' and d d' so that the selvage edges at 43 and 44
are on the outermost portion of the dressing, while the more
ragged raw edges 45 and 46 lie underneath same.
This embodiment may also contain at least one ply of
absorbent crepe cellulose wadding surrounding the absorbent
matrix of deregistered tow for enhancing the spreading of
fluid into the tow, as described and shown in Figure 4 above.
This structure will produce an extremely confortable dressing
that will produce a controlled pressure on the wound, while
preventing or avoiding any trauma to the patient.
While deregistered acetate tow is described above, it is
most important that whatever fiber material is used that it be
permanently crimped and deregistered. A thusly treated material
will surprisingly act as being more absorbent than prior art
absorbent batts and will have no loose ends, as opposed to
staple fiber lengths that would have loose protruding edges
that could possibly cause problems for the patient.
Since it is obvious that many changes and modifications
can be made in the above-described details without departing
from the nature and spirit of the invention, it i9 to be
understood that the invention is not ~imited to said details
except as set forth in the appended claims.
