CA3064498C

CA3064498C - Compression stocking

Info

Publication number: CA3064498C
Application number: CA3064498A
Authority: CA
Inventors: Hans B. Bauerfeind; Andreas TUTTE; Hans-Jurgen Thoma
Original assignee: Bauerfeind AG
Current assignee: Bauerfeind AG
Priority date: 2017-05-24
Filing date: 2018-05-24
Publication date: 2020-11-24
Anticipated expiration: 2038-05-24
Also published as: EP3630032B1; WO2018215601A1; DE102017005187A1; ES2884904T3; CA3064498A1; RU2719810C1; EP3630032A1

Abstract

The present invention relates to compression stockings, in particular of compression class I, methods for the production thereof and the use of such compression stockings. The present invention relates in particular to a compression stocking having a tubular compression zone, said compression zone preferably exerting a pressure in the ankle region of at least 2.4 kPa and not more than 2.8 kPa, and the compression zone being formed by a knitted fabric having a weft thread, characterized in that the weft thread has a core thread with a fineness of at least 470 dtex.

Description

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.

2 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

3 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.
=

4 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 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.

6 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.

7 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

8 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

9 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:

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.

11 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

12 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.

Claims

CLAIMS:

1. A compression stocking (100) having a tubular compression region (10), wherein the compression region (10) is formed from a knitted fabric (11) having a weft thread (12), wherein the weft thread has a core thread having a yarn count of at least 470 dtex, and wherein the compression region (10) in the ankle region exerts a compression pressure of at least 2.4 kPa and at most 2.8 kPa.

2. The compression stocking (100) as claimed in claim 1, wherein the weft thread has a core thread having a yam count of at least 605 dtex and at most 700 dtex.

3. The compression stocking (100) as claimed in claim 1 or 2, wherein the core thread of the weft thread comprises elastane or is composed thereof.

4. The compression stocking (100) as claimed in any one of claims 1 to 3, wherein the core thread of the weft thread is wrapped.

5. The compression stocking (100) as claimed in any one of claims 1 to 4, wherein the weft thread has a yarn count of at least 605 dtex.

6. The compression stocking (100) as claimed in any one of claims 1 to 4, wherein the weft thread has a yam count of at least 700 dtex.

7. The compression stocking (100) as claimed in any one of claims 1 to 6, wherein the weft thread has a force/elongation behavior of 0.03 N/cm to 0.04 N/cm.

8. The compression stocking (100) as claimed in any one of claims 1 to 7, wherein the compression region in the ankle region when putting on the compression stocking is elongated by at least 5% and at most 25%.

9. The compression stocking (100) as claimed in any one of claims 1 to 8, wherein 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.

10. The compression stocking (100) as claimed in any one of claims 1 to 9, wherein the compression stocking is individually produced.

11. A method for producing a compression stocking as claimed in any one of claims 1 to 10, comprising the following method steps:
a) measuring at least 5 circumferential measurements of a lower leg or of a leg;
b) knitting the compression stocking as claimed in any one of claims 1 to 10 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 measurements from step a).

12. A method for producing a compression stocking as claimed in any one of claims 1 to 10, comprising the following method steps:
a.) measuring at least 5 circumferential measurements of a lower leg, or at least 10 circumferential measurements of a leg;
b.) interpolating the at least 5 circumferential measurements or the at least circumferential measurements;
c.) knitting the compression stocking as claimed in any one of claims 1 to 10 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 measurements from step a), and wherein the compression stocking has dissimilar circumferential measurements, which are based on the interpolated circumferential measurements from step b).