Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Compression stocking
SPECIFICATION
The present invention relates to compressidn stockings, in particular
compression stockings of
compression class I, to a method for producing said compression stockings, and
to the use of
.. such compression stockings.
Compression stockings, in some instances also referred to as orthopedic
stockings or support
stockings, are well known, for example from DE 8814047 U 1 . Said compression
stockings are a
substantial component part of compression therapy, for example when treating
varicose veins,
leg vein thrombosis, post-thrombosis syndrome, as well as lymphedema, "exposed
legs", and
lipedema. Compression stockings generate external pressure on the tissue of
the enclosed leg so
as to destress the damaged vein or lymph system of said leg. A compression
stocking is
manufactured such that the exerted pressure increases in the direction of
gravity from top to
bottom, in a manner analogous to the tissuq pressure. This pressure is adapted
to the degree of
sickness of the patient and is graduated into the compression classes I to IV.
Compression
.. stockings of compression class I herein exert a compression of 2.4 to 2.8
kPa, this corresponding
to a compression pressure of 18 mmHg to 21 mmHg. Compression stockings of
compression
class II exert a compression of 3.1 to 4.3 kPa, this corresponding to a
compression pressure of 23
to 32 mmHg. Compression stockings of compression class III exert a compression
of 4.5 to
6.1 kPa, this corresponding to a compression pressure of 34 to 46 mmHg.
Compression stockings
of compression class IV exert a compression of at least 6.5 kPa, this
corresponding to a
compression pressure of at least 49 mmHg. Compression stockings in a weaker
embodiment can
also be used as a prophylactic, for example against travel thrombosis, or as a
support for
employees in jobs that require permanent standing.
In order to be seamless, a compression stocking is in most instances knitted
by the circular
knitting method. A second variant are flat-knitted compression stockings which
are not produced
by the circular-knitting method but are stitched together using a seam so as
to be tube-like. On
account thereof, the contours of the legs can be substantially better
tailored. Flat-knitted
compression stockings are typically used in the case of severe vein problems
or edema, and are
in the compression classes II to IV.
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Compression stockings are embodied so as to be knee length, half-leg length,
thigh length, and likewise
as pantyhose. Said compression stockings are available selectively with or
without openings for toes.
Peripheral artery disease (PAD), which colloquially is also referred to as
intermittent claudication, is a
disorder in the arterial blood supply to the extremities. This sickness
belongs to one of the chronic
vascular diseases of the arteries. To date, compression stockings are not
permitted for use in the
treatment of peripheral artery disease since there is the risk in patients
suffering from peripheral artery
disease that any external pressure exerted on the blood vessels worsens the
disorder of the latter. It is
therefore desirable to provide compression stockings which can also be worn by
PAD patients.
Compression stockings from the prior art have to be significantly elongated
when said compression
stockings are to be pulled over the leg. The user requires a corresponding
force or has to be aided in
order for said elongation be provided.
The technical issue on which the present invention is based is providing a
compression stocking, in
particular a compression stocking of compression class I, which has to be
elongated to a lesser degree
when being put on. The compression stocking according to the invention should
also preferably be
suitable for people which suffer from peripheral artery disease.
In one aspect, the present invention provides a compression stocking having a
tubular compression
region, wherein the compression region is formed from a knitted fabric having
a weft thread, wherein
the weft thread has a core thread having a yarn count of at least 470 dtex,
and wherein the compression
region in the ankle region exerts a compression pressure of at least 2.4 kPa
and at most 2.8 kPa.
It has been surprisingly demonstrated that when using a weft thread having a
core thread having a yarn
count of at least 470 dtex, thus a comparatively thick weft thread for
compression stockings, in
particular for compression stockings of compression class I, a compression
stocking having a woven
fabric which forms the compression region and which in terms of the dimensions
thereof can be almost
identical to the dimensions of the leg of the patient, and the
Date Recue/Date Received 2020-05-06
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patient when putting on the stocking thus does not have to pre-elongate the
stocking in the case
of more than 80% of the leg area covered by the stocking in order for said
stocking be able to be
placed over, thus put on, the corresponding leg portion. The circumferential
values of the new
tailored stocking can deviate only to a minor extent in comparison to the
circumferential values
of the patient's leg as actually measured. The patient can thus put on the
compression stocking
more easily, and any aid can thus be dispensed with.
A conventional knitting thread such as is also used in compression stockings
from the prior art
can be advantageously used in the compression stocking according to the
invention. The same
knitting technique as in conventional compression stockings can also be
advantageously used.
The knitting thread can thus form a knitted fabric from the prior art which
additionally has a weft
thread having a core thread having a yarn count of at least 470 dtex.
The weft thread, on account of the material thickness of the core thread of
the weft thread, or of
the weft thread per se, respectively, that is increased according to the
invention, is more inelastic
and therefore requires less expansion so as to achieve the prescribed
compression values. A
compression stocking preferred according to the invention having in the ankle
region a
compression pressure of at least 2.4 kPa and at most 2.8 kPa, thus in the
range of compression
class I, advantageously preferably has a short-stretch elasticity, thus a
stiffness, which is present
in a comparable stocking of compression cldss III.
It has been surprisingly demonstrated that the compression stocking of
compression class I,
.. preferred according to the invention, in terms of the circumference thereof
being able to be
adapted to approximately the circumference of the patient's leg, is also
suitable for patients
which suffer from peripheral artery disease, and that moreover a compression
stocking according
to the invention which is adapted precisely to the patient's leg in the case
of such patients even
has a facilitating effect in terms of reversing the symptoms of the disorder.
The compression stocking according to the invention has a tubular compression
region which, as
is the case in compression stockings from the prior art, bears on the leg
region, for example on
the lower leg or on the lower leg and the thigh. The compression region at the
bottom
commences in the region of the ankle of the foot and from there extends
upward. According to
the invention, the compression region in the ankle region of the foot
preferably exerts a
compression pressure of at least 2.4 kPa and at most 2.8 kPa, this
corresponding to compression
class I in compression stockings.
=
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In the conventional measurement of a leg when selecting suitable compression
stockings, the
ankle region as measurement point B and the calf region as measurement point C
are in
particular used. The measurement point B indicates the ankle circumference,
thus the thinnest
location of the lower leg, and thus the smallest leg circumference. The
measurement point C
indicates the largest calf circumference. Further measurement points are the
measurement point
A as the circumference at the start of the little toe; the measurement point
D, thus the
circumference under the patella, in particular two finger widths below the
hollow of the knee; the
measurement point E, thus the circumference of the patella; the measurement
point F which lies
approximately at the center of the thigh; and the measurement point G which
lies approximately
at the end of the thigh.
According to the invention, the compression region at the measurement point B
preferably exerts
a compression pressure of at least 2.4 kPa and at most 2.8 kPa.
The compression stocking in one preferred embodiment is a circular-knitted
fabric. The tubular
compression region in one preferred embodiment is a circular-knitted fabric.
The compression stocking according to the invention can thus advantageously be
produced as a
circular-knitted fabric, just like a conventional compression stocking. The
knitted fabric of the
compression region in one preferred embodiment is composed of a knitting
thread (base thread)
which forms the knitted fabric, and the weft thread having a core thread
having a yarn count,
thus having a yarn count value, of at least 470 dtex. A conventional knitting
thread and a
conventional knitting technique can advantageously be used.
In one preferred embodiment the weft thread has a core thread having a yarn
count of at least
480 dtex. In one preferred embodiment the weft thread has a core thread having
a yarn count of
at least 500 dtex. In one preferred embodiment, the weft thread has a core
thread having a yarn
count of at least 550 dtex. In one preferred embodiment the well thread has a
core thread having
.. a yarn count of at least 600 dtex. In one preferred embodiment the weft
thread has a core thread
having a yarn count of more than 600 dtex. In one preferred embodiment the
weft thread has a
core thread having a yarn count of at least 605 dtex.
In one preferred embodiment the weft thread has a core thread having a yarn
count, thus having a
yarn count value, of at most 700 dtex. In one preferred embodiment the well
thread has a core
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thread having a yarn count of at most 680 dtex. In one preferred embodiment
the weft thread has
a core thread having a yarn count of at most 650 dtex.
In one preferred embodiment the weft thread has a core thread having a yarn
count of at least
605 dtex and at most 700 dtex. In one preferred embodiment the weft thread has
a core thread
5 having a yarn count of at least 610 dtex and at most 650 dtex. In one
preferred embodiment, the
weft thread has a core thread having a yarn count of at least 610 dtex and at
most 630 dtex. In
one preferred embodiment the weft thread has a core thread having a yam count
of at least
615 dtex and at most 625 dtex.
In the context of the present invention, "a yam count of at least x dtex" is
understood to be a yarn
count which corresponds to a value of x dtex or > x dtex, thus is coarser than
x dtex. In the
context of the present invention, "a yarn count of at most x dtex" is
understood to be a yam -
count which corresponds to a value of x dtex or < x dtex, thus is finer than x
dtex. The indication
of the yarn count thus relates to the yarn count value.
The weft threads which according to the invention are comparatively thick have
the advantage
that the weft thread, on account of the high yarn count value of the core
thread, which leads to a
likewise higher yarn count value of the weft thread, becomes more inelastic
and thus requires
less elongation in order for the prescribed compression values to be mirrored.
The yarn count of the core thread is indicated in dtex, thus in the unit tex
according to IS01144
and DIN60905, according to the legislation pertaining to units in metrology of
July 2, 1969. Tex
is a unit in the basic unit of the tex system, wherein 1 tex = 1 g of thread
per 1000 m, thus
1 dtex = 1 g/10,000 m.
A gravimetric testing method according to DIN EN ISO 1973 (weighing method) is
preferably
used as a testing method for determining the fiber count, in which fiber
bundles which contain a
specific number of fibers are cut to an established cut length and are
subsequently weighed.
Alternatively, the Vibroskop method (oscillating method) which is also
standardized in
DIN EN ISO 1973 can be used as the testing method.
In one preferred embodiment the core thread of the weft thread is elastic.
The core thread preferably comprises elastane or is composed thereof.
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In one preferred embodiment the well thread is elastic.
In one preferred embodiment the core thread of the well thread is wrapped.
The core thread of the well thread is preferably double-wrapped. The wrapping
thread of the
well thread preferably comprises polyamide pr is composed thereof.
When the core thread is not wrapped, the core thread forms the weft thread.
In one preferred embodiment the weft thread has a yarn count value of more
than 605 dtex. In
one preferred embodiment the well thread has a yarn count value of at least
650 dtex.
In one preferred embodiment the well thread has a yarn count, thus a yarn
count value, of at least
605 dtex, in particular at least 700 dtex.
The indications of the yarn count of the well threads relate to a wrapped as
well as a non-
wrapped well thread.
In the case of a wrapped weft thread, the total thickness of the weft thread
is advantageously yet
again increased. In the case of a well thread in which the core thread is
wrapped, the yarn count
of the weft thread, composed of the core thread and at least one wrapping
thread, is preferably
determined according to the French standard.
The weft thread, in particular the wrapped well thread, preferably has a yarn
count of at least
750 dtex and at most 900 dtex. The weft thread, in particular the wrapped the
well thread,
preferably has a yarn count of at least 750 dtex and at most 820 dtex. The
well thread, in
particular the wrapped well thread, preferably has a yarn count of at least
725 dtex.
In one preferred embodiment the well thread has a force/elongation behavior of
0.03 N/cm to
0.04 N/cm, in particular in the non-linear range.
On account of an individual production of the compression stocking according
to the invention,
said compression stocking can be advantageously adapted to the individual leg
circumferences of
the patient. On account thereof, it is even better possible for the
compression stocking according
to the invention to be able to be worn also by PAD patients.
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According to the invention, the tubular compression region of the compression
stocking in the
longitudinal direction preferably has dissimilar circumferences. The
circumferences are
preferably adapted to approximately the leg circumference of the patient. The
circumferences are
preferably dissimilar at at least five points along the tubular compression
region, wherein the
region which bears on the ankle, thus the ankle of the foot, and the region
which bears on the
calf, being in particular included in said five points, since the ankle
usually represents the
smallest circumference of the lower leg, and the calf usually represents the
largest circumference
of the lower leg.
In one preferred embodiment the compression region in the ankle region, in
particular at the
measurement point B, when putting on the compression stocking is elongated by
at most 25%,
preferably at most 20%.
In one preferred embodiment the compression region in the ankle region when
putting on the
compression stocking is elongated by at least 5% and at most 25%, preferably
at most 20%.
In one preferred embodiment the compression region in the ankle region when
putting on the
compression stocking is elongated by at least 15%.
In one preferred embodiment the compression region in the calf region, in
particular at the
measurement point C, when putting on the compression stocking is elongated by
at least 25%.
In one preferred embodiment the compression region in the calf region when
putting on the
compression stocking is elongated by at least 5% and at most 25%.
Apart from the compression pressure of at least 2.4 kPa and at most 2.8 kPa
that defines
compression class I and which is also referred to as the stagnation pressure,
the operating
pressure is also relevant. Said operating pressure acts primarily in a dynamic
manner when the
person wearing the stocking is moving. Minor anatomic variations on the leg
during the
movement generate additional pressure components, this being said operating
pressure. The
stiffness or else the slope value is used as the technical parameter for
measuring the operating
pressure. The European Committee for Standardization (CEN) has defined the
stiffness as the
pressure increase in millimeters of mercury (mmHg) which results when the
compression
stocking is over-elongated by 1 cm. Since the stiffness is also a function of
the circumference of
the leg in the measurement region, the stiffness is preferably measured in the
ankle region, in
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particular at the measurement point B, of the leg. A typical circumference in
the ankle region is
approximately 24 cm. The stiffness can however also be determined at other
measurement
regions, for example in the calf region. The typical circumference for the
calf is approximately
38 cm.
The operating pressure is a factor that must not be neglected in the case of
medical compression
stockings. Compression stockings with a high stiffness have a high requirement
in terms of the
exact fit since the short-stretch material from which such compression
stockings are composed
permits only very minor measuring tolerances.
It has now been surprisingly demonstrated that a compression stocking
according to the
invention can advantageously have an increased stiffness and herein can be
manufactured to an
exact fit. The increased stiffness advantageously leads to a higher operating
pressure and the
simultaneously low stagnation pressure, for example a compression pressure of
at least 2.4 kPa
and at most 2.8 kPa which defines compression class I. A high operating
pressure at a low
stagnation pressure surprisingly and advantageously permits the use of the
compression stocking
according to the invention with PAD patients, since the compression stocking
in the static state
builds up almost no pressure while said compression stocking provides the
required pressure
when elongated on account of the movement of the leg.
In one preferred embodiment the tubular compression region at a circumference
of 24 cm has a
stiffness of at least 5 mmHg/cm and at most 12 mmHg/cm.
In one preferred embodiment the tubular compression region at a circumference
of 24 cm has a
stiffness of at least 6 mmHg/cm and at most 12 mmHg/cm. In one preferred
embodiment the
tubular compression region at a circumference of 24 cm has a stiffness of at
least 6 mmHg/cm,
preferably of at least 8 mmHg/cm.
The tubular compression region at a circumference of 24 cm particular
preferably has a stiffness
of at least 8 mmHg/cm and at most 10 mmHg/cm.
The tubular compression region at a circumference of 24 cm particularly
preferably has a
stiffness of at least 6 mmHg/cm and at most 11 mmHg/cm.
In one preferred embodiment the tubular compression region in the ankle
region, in particular at
the measurement point B, has a stiffness of at least 6 mmHg/cm and at most 12
mmHg/cm. In
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one preferred embodiment the tubular compression region in the ankle region,
in particular at the
= measurement point B, has a stiffness of at least 6 mmHg/cm.
In one preferred embodiment the tubular compression region at a circumference
of 38 cm has a
stiffness of at least 0.5 mmHg. In one preferred embodiment the tubular
compression region at a
circumference of 38 cm has a stiffness of at least 0.5 mmHg and at most 6
mmHg.
In one preferred embodiment the tubular compression region at a circumference
of 38 cm has a
stiffness of at least 0.5 mmHg and at most 5 mmHg.
In one preferred embodiment the tubular compression region in the calf region,
in particular at
the measurement point C, has a stiffness of at least 0.5 mmHg/cm and at most 5
mmHg/cm. In
one preferred embodiment the tubular compression region in the calf region, in
particular at the
measurement point C, has a stiffness of at least 0.5 mmHg/cm.
In one preferred embodiment the compression stocking has a compression-reduced
heel, in
particular in the form of a heel pocket. Said heel pocket is preferably
knitted without any
compression and is capable of being relatively elongated. The heel-forming
loops in comparison
to the loops of the compression region herein are preferably knitted at a
ratio of approximately
60 to 40, the heel region thus containing more loops per portion than the
compression region. On
account thereof, the "heel pocket" is somew. hat larger, and the entry into
the stocking is more
comfortable. However, this also leads to a hard transition to the circular
compression region
being generated in the first stitch course after the heel pocket in the region
of the instep. Pressure
at this location can be perceived as uncomfortable. Therefore, the compression
stocking
preferably has a transition region knitted thereinto, preferably at a width of
approximately 2 cm,
said transition region advantageously configuring a mediating compression
value in relation to
the two neighboring regions.
In one preferred embodiment the compression stocking is individually produced.
On account
thereof, the circumference of the compression region can advantageously be
adapted individually
to the various measuring points on the leg such that the best possible fit is
achieved and the
compression stocking is also particularly suitable for PAD patients.
The invention also relates to a method for producing a compression stocking
according to the
invention, comprising the following method steps:
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a) measuring at least 5 circumferential measurements of a lower leg or of a
leg;
b) knitting the according to the invention from a knitting thread and the weft
thread, wherein
the tubular compression region of the compression stocking has dissimilar
circumferential measurements which are based on the at least 5 measured
circumferential
5 measurements from step a).
In one preferred embodiment the method according to the invention comprises
the following
method steps:
a) measuring at least 5 circumferential measurements of a lower leg or of a
leg;
b) interpolating the at least 5 circumferential measurements;
10 c) knitting the compression stocking according to the invention from a
knitting thread and
the weft thread, wherein the compression stocking has dissimilar
circumferential
measurements which are based on the interpolated circumferential measurements
from
step b).
Interpolated values between the individual measured points are thus preferably
utilized for
knitting the compression stocking.
Preferred embodiments of the method are also derived from the preferred
embodiments of the
compression stocking.
According to the invention, at least 5 circumferential measurements of the
lower leg, or at least
10 circumferential measurements of the leg, are preferably measured, wherein
more than 5
circumferential measurements, or 10 circumferential measurements,
respectively, are preferably
measured. For example, 20 measured values and more can be taken using the
Bauerfeind
Bodytronic 600 measuring system, this advantageously leading to a compression
stocking with
an even better fit. In particular embodiments of the method according to the
invention at least 20
circumferential measurements of the lower leg or of the leg are measured.
The invention also relates to a compression stocking, in particular of
compression class I, said
compression stocking being produced and/or being producible by the method
according to the
invention.
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The invention also relates to the use of a compression stocking according to
the invention, in
particular of compression class I, for treating a leg disorder or as a
prophylactic for a leg
disorder, wherein the leg disorder can in particular be a peripheral artery
disease.
Preferred embodiments are also derived from the dependent claims.
The invention will be explained in more detail by means of the following
exemplar and the
figures without said example and said figures to be understood as being
limiting. In the figures:
figure 1 shows one preferred embodiment of compression stocking
according to the
invention; and
figure 2 shows a fragment of the compression region of the
compression stocking
from figure 1.
EXEMPLAR
The circumference of a leg of a test person was measured at five measurement
points, inter alia
at the ankle (measurement point B, height 16.7 cm, measured in each case from
the heel) and at
the calf (measurement point C, height 36.5 cm). The circumference at the
measurement point B
.. was 24.2 cm; the circumference at the measurement point C was 36.5 cm.
Furthermore, the
circumference at the measurement point B1 (height 26.3 cm) was 29.8 cm; 34.4
cm at the
measurement point B2 (height 31.2 cm); and 34.9 cm at the measurement point D
(height
41.7 cm).
A compression stocking of compression class I of half leg length was knitted
from a knitting
thread and a weft thread on a conventional circular knitting machine (single-
cylinder circular
knitting machine, diameter 3.5" to 6"). The knitting thread herein in a
conventional manner
formed the circular knitted fabric that forms the tubular compression region.
The knitting thread
was a knitting thread such as is also used in conventional compression
stockings. A weft thread
was inserted into the knitted fabric forming the tubular compression region.
The weft thread was
.. a double-wrapped weft thread, the core thread thereof being composed of
elastane and having a
yam count of 620 dtex (Lycra 620 dtex, type 136c). The wrapping threads were
composed of
polyamide (44fl3x2 PA 6.6 ME). The weft thread had a yarn count of 790 dtex,
measured
according to the French standard. The core thread in the force/elongation
behavior had an
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increase of 0.03133 N/cm. The wrapped weft thread in the force/elongation
behavior had an
increase of 0.03890 N/cm.
The compression stocking thus knitted had the following parameters in the
compression region:
a) Stagnation pressure (RAL GZ-387):
.. Measurement point B: 2.57 kPa
Measurement point Bl: 2.06 kPa
Measurement point B2: 1.99 kPa
Measurement point C: 1.55 kPa
Measurement point D: 1.85 kPa
b) Elongation in the stocking when worn:
Measurement point B: 5% to 20%
Measurement point C: 5% to 25%
c) Operating pressure:
Measurement point B: slope value: approx. 9.0 mmHg/cm
Measurement point C: slope value: approx. 2.0 mmHg/cm
Figure 1 shows the compression stocking (100) according to the invention from
the exemplar in
the state when worn. The compression stocking (100) has a tubular compression
region (10)
having the measurement points B and C.
Figure 2 shows a fragment from the compression region (10) of the compression
stocking from
figure 1 in the elongated state. The compression region (10) is formed by a
knitted fabric formed
from a knitting thread (11), the comparatively thick weft thread (12) being
inserted into said
knitted fabric.
