WO2014184324A1

WO2014184324A1 - Decongestion garment for treating lymphedema

Info

Publication number: WO2014184324A1
Application number: PCT/EP2014/060025
Authority: WO
Inventors: Jean-Baptiste VALSAMIS; Giovanni-Paolo BELGRADO
Original assignee: Universite Libre De Bruxelles
Priority date: 2013-05-15
Filing date: 2014-05-15
Publication date: 2014-11-20

Abstract

Compression garment (10, 20) for treating lymphedema, comprising a multi-layer sheet (11, 21) arranged for being wrapped around a body part and one or more fasteners (12, 22) for holding the multi-layer sheet in the wrapped configuration, wherein the multi-layer sheet (11, 21) comprises an inelastic layer (113, 213) extending throughout the sheet for maintaining a cross sectional perimeter of the multi-layer sheet substantially constant once wrapped and fastened, and a resilient layer (114a, 114b, 214) arranged at an inner side (116, 216) of the multi-layer sheet such that, in use, the resilient layer is interposed between the body part and the inelastic layer, characterised in that the garment comprises a temperature control means (14, 24, 131, 231) including heating means (13, 23) for setting a temperature at the inner side (116, 216) of the multi-layer sheet (11, 21) between 36°C and 40°C.

Description

DECONGESTION GARMENT FOR TREATING LYMPHEDEMA

[0001] The present invention is related to so-called compression garments for therapeutic treatment of lymphedema. In particular, the invention is related to compression garments involving multilayer (or multicomponent) sheets which can be wrapped around a body part and be fastened in such a position in order to exert a compressive force on the skin of the body part.

[0002] Lymphedema is a condition involving a considerable swelling of a body part, manifesting itself often at the limbs, and is caused by an insufficiency of the lymphatic system where lymphatic transport falls below the capacity needed to handle the load of microvascular filtrate, such as plasma protein and cells that normally leak from the bloodstream into the interstitium and waste of cellular metabolism unable to return by microcirculation. This insufficiency may have congenital causes, may arise as a consequence of functional deficiency or trauma, e.g. after an operative dissection, or may arise from infectious diseases. The lymphatic load which cannot be timely evacuated, including excess water, filtered/diffused plasma proteins, extravascular blood cells and parenchymal/stromal cell products, accumulates in the extracellular space causing swelling and skin lesions if the edema is not treated.

[0003] The treatment of lymphedema of the limbs, also referred to as peripheral lymphedema, is the subject of a consensus paper of the International Society of Lymphology ("The diagnosis and treatment of peripheral lymphedema", Lymphology 42 (2009), pp. 51 -60). Swelling can be reduced by non-operative, combined physical therapy (CPT), also referred to as Complete or Complex Decongestive Therapy, which involves a two-stage treatment program. In a first phase, a specific light manual massage is applied to the infected region, in combination with a range of motion exercise and a compression treatment by application of multilayered bandage wrapping. A second phase, initiated promptly after the first phase, aims at preserving the results obtained in the first phase by wear of low-stretch elastic stockings or sleeves for applying compression to the limbs. These low-stretch elastic garments should enable to apply a compression level as high as tolerated by the patient, typically between 20 and 60 mm Hg.

[0004] The present inventors found that the multilayered bandage wrapping, when correctly applied, is capable of decongesting quite rapidly (depending on the kind of edema, within about 24 hours - but the treatment can last up to 15 days) the edema. Studies carried out by the inventors showed that the multilayered bandages enable to have the proteins accumulated in the edema resorbed by injecting them in the intradermal and subcutaneous space. These studies also showed an increase of liquid return into the vascular network.

[0005] Unfortunately, multilayer bandages are not a patient's preferred solution, since they considerably inhibit the range of motion. Additionally, during the first phase of treatment, such multilayer bandages need to be applied and reapplied daily, which is time-consuming. Moreover, the efficacy of the multilayered bandages greatly depends on the therapist's skills in applying them.

[0006] Solutions have therefore been provided in the prior art as a substitute for multilayered bandages. US 6254554 describes a compression sleeve for treating lymphedema, comprising an outer inelastic fabric layer to constrain swelling of the limb and an inner padding layer made of a high density foam. The padding layer shows sufficient compressibility to place an even pressure on the patient's limb when the inelastic fabric is tightened around the limb by fastening straps.

[0007] A similar garment is described in WO 2010/144492. In this case, the inelastic layer is formed of a short-stretch material with maximum elasticity of 15-90%, such that the garment provides a compression level that falls within the range between 8 and 50 mm Hg when applied at or near end- stretch. Also, the padding layer is made of a spacer fabric rather than a foam. [0008] WO 2012/021777 describes a compression garment for wrapping a lower part of a leg having a primary wrap made of a non-elastic material. At the interior of the wrap, an inflatable bladder is provided inside a pocket attached to the wrap. The bladder can be inflated manually with an air pump and can be equipped with a pressure gauge for indicating a pressure level inside the wrap. When the bladder is inflated, the non-elastic primary wrap remains stiff and is not stretched.

[0009] Another garment for treating lymphedema is described in US

5916183, and is formed of a sleeve with inwardly projecting elastomeric fingers and externally fitted pressure adjusting circular bands. When the sleeve is fitted to a patient's limb, the fingers impose a grid pattern of pressure points against the skin. It is thought that the space around and between the pressure points provide channels under the skin through which lymphatic fluids are able to migrate up the arm to the shoulder where healthy nodes process it and channel it to the large veins. In US 6656141 , by the same inventor, the garment is composed of a plurality of sleeves which are slidably received over one another. The innermost sleeve, in contact with the skin is provided with the above inwardly projecting elastomeric fingers, whereas the outer sleeve(s) is/are configured to apply a pressure to the innermost sleeve, thereby increasing the therapeutic pressure applied by the innermost sleeve on the limb.

[0010] A disadvantage of the above garments is that the elastomeric fingers can create pressure peaks on the skin causing injury and/or skin damage. Another disadvantage of the multilayer sleeve of US 6656141 is that a suitable pressure cannot be maintained when the lymphedema reduces in volume.

[0011] US 2007/0179421 describes yet another garment for treating lymphedema composed of overlapping bands engineered with different levels of compression. The bands are provided with foam padding, which may be pyramid shaped, facing the inner layer. It is thought that the pyramid shaped areas massage the affected area during wear and break up fibrotic areas, effectively reducing lymphedema long term. A disadvantage of this garment, is that the placement of the various bands is time consuming and should be carried out by a skilled clinician in order to be applied correctly. [0012] The present inventors found that the above compression garments are effective in draining the liquid part of the lymphedema. However, the proteinic part (mainly collagen and albumine) of the lymphedema is not or weakly affected and remains.

[0013] Aspects of the present invention therefore envisage to provide such sleeves, garments and similar devices which are more effective in the physical treatment of lymphedema. Aspects of the present invention envisage to provide garments as a more effective and easier-to-use substitute to multilayer bandages. Aspects of the present invention envisage to provide garments which additionally allow to drain the liquid part as well as the proteinic part of a lymphedema.

[0014] According to aspects of the invention, there is therefore provided a garment for treating lymphedema as set out in the appended claims.

[0015] Advantageous aspects of the present invention are set out in the dependent claims.

[0016] A method of treating lymphedema is also described. The method comprises providing a compression garment according to aspects of the invention and wrapping the garment around the body part suffering from lymphedema. The garment is tightened to obtain a compressive (static) pressure at a skin interface of at least 40 mm Hg. A temperature controller is coupled to the garment and a temperature at, or in proximity of, the skin is controlled to fall between 36°C and 39°C.

[0017] Aspects of the invention will now be described in more detail with reference to the appended drawings, which are illustrative only and wherein same reference numbers indicate same features, wherein:

[0018] Figure 1 represents a wrapped-open, internal view of a garment according to the invention with cut-outs to show the internal structures;

[0019] Figure 2 represents a cross section of the garment of figure 1 taken along line 1 -1 ';

[0020] Figure 3 represents a wrapped-open, internal view of another garment according to the invention with cut-outs to show the internal structures;

[0021] Figure 4 represents a cross sectional view of the garment of figure 3, but without the fastening straps; [0022] Figure 5 represents evolution of the pressure level p at the skin interface in function of time t, as measured by a pressure gauge;

[0023] Figure 6 represents an exploded cross sectional view of another garment according to aspects of the invention.

[0024] Thorough studies carried out by the present inventors revealed that an effective decongesting treatment of lymphedema can be obtained by the combination of:

1 . the application of a large and advantageously time-varying pressure at the interface of the skin; and

2. an increase of temperature at the skin interface to at least, or above 36°C. It has been found that the increased temperature liquefies the edema made up of proteins and water, which at the normal skin temperature of about 32.5°C is in a gel state. The liquefaction was found to start from about 36°C. Additionally, the skin temperature increase causes vasodilation of the cutaneous arteriovenous capillaries, which is accompanied by an increased capillary permeability.

[0025] Even though vasodilation is an a priori aggravating condition for edemas, causing swelling and volume increase, it has surprisingly been found to nevertheless become beneficial when a suitable external pressure is exerted in order to increase the tissue pressure and inverse the net driving force in the Starling equation of fluid movement across capillary membranes to favour absorption processes by the capillaries. Hence, according to the invention, the temperature increase is provided in combination with the application of a compressive pressure at the skin interface, advantageously of at least 36 mm Hg, advantageously at least 40 mm Hg, advantageously at least 45 mm Hg, and advantageously 90 mm Hg or less, advantageously 80 mm Hg or less, advantageously 70 mm Hg or less. Additionally, the compressive pressure is advantageously a time-varying pressure at the skin interface, due to arterial pulsation and/or patient movement, advantageously varying between amplitudes falling in the range between 5 mm Hg and 300 mm Hg, advantageously with amplitudes higher than or equal to 10 mm Hg, advantageously higher than or equal to 15 mm Hg, advantageously higher than or equal to 35 mm Hg, advantageously higher than or equal to 40 mm Hg, and advantageously with amplitudes smaller than or equal to 200 mm Hg, advantageously smaller than or equal to 100 mm Hg, advantageously smaller than or equal to 90 mm Hg. The pressure fluctuation due to arterial pulsation and/or patient movement is advantageously at least 20 mm Hg, advantageously at least 35 mm Hg. The combination of higher temperature and pressure thus has a synergistic effect leading to an increased absorption of edema matter, and particularly of proteins in addition to water. Present inventors have thus developed garments, which will be described in what follows, to put the above knowledge into practice and provide improved effectiveness in lymphedema treatment.

[0026] Referring to Fig. 1 , a garment 10 according to the present invention comprises a multilayer sheet 1 1 , which may be capable of being wrapped around a body part, such as, but not limited to, a patient's limb. For keeping the sheet 1 1 wrapped, the garment 10 comprises fastening means, such as fastening straps 12, comprised of a strap member 121 attached at one edge 1 1 1 of the sheet 1 1 and a ring 122 attached to the opposite edge 1 12 of sheet 1 1 . Ring 122 has an aperture capable of receiving a free end of strap member 121 through it, when sheet 1 1 is wrapped. Suitable pads 123 made of a hook and loop material may be attached on the strap members 121 and possibly on the sheet 1 1 for securing the free end of the strap 121 to the sheet 1 1 upon tightening the strap through ring 122. It will be convenient to note that the straps 121 and the hook and loop pads 123 may be replaced by any other suitable fastening means, such as clasps.

[0027] An advantage of straps 12 is that they allow for wrapping body parts which are sized within a considerable size range. This is advantageous, since the patient will not need to use or buy a large number of differently sized garments 10 as the lymphedema will reduce in volume. Other fastening means which account for same effects will be advantageous as well.

[0028] The multilayer sheet 1 1 may have a shape suitable for the body part that is to be wrapped. In particular, Fig. 1 shows a sheet 1 1 with a width decreasing from top to bottom, which would be suitable e.g. for wrapping an upper leg. [0029] Fig. 2 shows a cross sectional structure of multilayer sheet

1 1 as taken along section line 1 -1 ' in Fig. 1 . The sheet comprises an inelastic layer 1 13, which advantageously forms the outer layer of sheet 1 1 and advantageously substantially extends throughout the sheet 1 1 . The term inelastic refers to the fact that the material of layer 1 13 cannot be significantly stretched in the plane of sheet 1 1 . Inelastic layer 1 13 hence is made of a non- stretch or short-stretch material. That is, layer 1 13 advantageously has a maximal stretch of 15%, advantageously a maximal stretch of 10%, advantageously a maximal stretch of 5%, advantageously a maximal stretch of 2%. The maximal stretch may be determined using the relevant standard for the type of material that is used. By way of example, the relevant standard for fabrics is ASTM 5034; for rubber materials ASTM D2240; for foam materials ASTM D3575; and for plastic materials ASTM D785. By way of example, inelastic layer 1 13 may be made of a nonwoven fabric made of synthetic or natural fibres. It will be convenient to note that a variety of other materials may be used as inelastic layer.

[0030] The function of inelastic layer 1 13 is to provide a rigid layer

(i.e. non-stretch or low-stretch) when the sheet 1 1 is wrapped, such that the cross sectional perimeter of the wrapped sheet 1 1 remains substantially unaltered upon tightening the fastening means 12. This is important for obtaining a compressive pressure at the skin interface. Another, advantageous function of inelastic layer 1 13 is to act as support for the other layers of sheet 1 1 . Also, the fastening means are advantageously attached to the inelastic layer 1 13 of sheet 1 1 .

[0031] It will be convenient to note that garments of the invention are advantageously portable and advantageously allow for movement of any joint wrapped by the garment, since a patient's movement causes muscular pressure increase, which increases pressure variations at the skin and makes lymphedema treatment more effective. Therefore, inelastic layer 1 13 is preferably formed such as to allow a movement of the body part, such as knee or elbow bending. In this regard, garment 10 may comprise a successive disposition of a plurality of multilayer sheets 1 1 flexibly attached to one another to provide for body part movement, with each sheet capable of being wrapped around the body part.

[0032] Multilayer sheet 1 1 further comprises one or more resiliently compressible layers provided at the inner side 1 16 of sheet 1 1 , which is the side arranged to face the body part when sheet 1 1 is wrapped and which opposes the outer side 1 15 where the inelastic layer 1 13 is provided. By way of example, the sheet 1 1 shown in Figs. 1 and 2 comprises two stacked resiliently compressible layers 1 14a and 1 14b. More or less (i.e. one or more) resilient layers may be provided as desired.

[0033] The goal of resilient layers 1 14a, 1 14b is to assist in obtaining pressure variations at the skin interface by exploiting the arterial blood pressure variation. This pressure variation imparts a gentle massage to the lymphedema, which in addition to the overall compressive pressure exerted by the inelastic layer 1 13, improves drainage of edema matter into the capillaries. Particularly advantageous are resilient layers having such viscoelastic properties to cause a phase shift in skin pressure variations relative to the arterial blood pressure. The resilient layers are hence configured to provide resilient compression at the skin interface during use of the garment. This means that the resilient layer must provide resiliency when the garment is wrapped and tightened around the body part to compress the lymphedema.

[0034] Resilient layers 1 14a and 1 14b are hence advantageously made of a visco-elastic material. The material of one, or some of the resilient layers has a Young's modulus, or a compressive modulus (ISO 3386-1 ), as determined in a direction perpendicular to the plane of the sheet or layer, advantageously smaller than or equal to 500 MPa, advantageously smaller than or equal to 100 MPa, advantageously smaller than or equal to 50 MPa, advantageously smaller than or equal to 20 MPa, advantageously smaller than or equal to 10 MPa, advantageously smaller than or equal to 1 MPa.

[0035] Resilient layers 1 14a, 1 14b advantageously have a considerable viscous component, providing a relaxation time with relaxation constant τ larger than or equal to 1 ms. They can be made of one or a combination of known padding materials, such as but not limited to: a high- density foam, such as a polyurethane foam, a polyethylene foam, an appropriate cellular material, a silicone gel, and a spacer fabric. They can as well be formed of different, stacked layers. Since lymphedemas may differ in their respective water content, it will be convenient to note that resilient layer(s) having different mechanical properties may be selected to treat the different edemas.

[0036] The one or more resilient layers are advantageously made of foam or other padding or cushioning materials and may have densities advantageously larger than or equal to 10 kg/m³, advantageously larger than or equal to 15 kg/m³, advantageously larger than or equal to 20 kg/m³, and advantageously smaller than or equal to 150 kg/m³, advantageously smaller than or equal to 100 kg/m³.

[0037] The one or more resilient layers 1 14a, 1 14b advantageously have a total thickness of at least 1 cm, advantageously at least 1 .5 cm, advantageously at least 2 cm. Such thickness values ensure that a resiliency is maintained when the garment 10 is tightened around the body part to compress the lymphedema. In other words, the resilient layers advantageously provide for resilient compression of the lymphedema.

[0038] The mechanical properties of the material of the resilient layers can be calculated by approximating the resilient material according to the Kelvin-Voigt model (a spring and a damper in parallel connected to a mass). To determine the spring constant and the damping constant, the deformation of a sample of the resilient material subject to the action of an external mass m is studied. The vertical motion x of the gravity centre of this mass is recorded by an appropriate device. The motion equation of the Kelvin-Voigt model is given by the Newton equation: rax. + bx + kx = rag

Where χ, χ, χ are respectively the position, the velocity and the acceleration of the mass m, g is the gravity constant, k (N/m) is the spring constant of the resilient material and b (Ns/m) the coefficient of the damper. The x-axis is vertical downwards and the origin is positioned when the mass touches the top surface of the sample. [0039] A static measurement is sufficient to determine the spring constant: the deformation of the sample due to the known mass gives a deformation of the top surface (position of the external mass x_s). Using the above equation at equilibrium, the spring constant k is: rag

This law is approximately linear for small deformations (x_s is below 50% of the sample thickness).

[0040] To define the damping constant, a dynamic motion is required. The external mass is sunk into the sample with a depth d smaller than 50% of the sample thickness and larger than twice x_s. Then the external mass is freely left to reach its equilibrium position x_s following the law (analytical solution of the motion equation):

_i - x(t) = Ae a + Be P + C

Where

2m

a

b + ¾²— 4km

2m

b— ¾²— 4km

d + mg/k

A = a

α - β

d + mg/k

Β = β

β - a

mg

C =

^~k

[0041] The tracked motion of the external mass is fitted with a least square curve fitting algorithm, in order to retrieve the coefficients a, giving the constant b. The value C can also give the constant k. The constants k and b vary according to the interfacial section S in contact with the external mass and the thickness h of the sample. To make them independent of the sample geometry, it is convenient to multiply k and b by h/S to have intrinsic parameters of the material (an approximation of the Young's modulus and of the viscosity).

[0042] The samples should have a geometry with a section of 4cm x

4cm and a thickness h of 1 cm. The mass should be high enough in order to ignore any inertial effect of the sample (m should be at least 10 times higher than the mass of the sample). Masses from 50g to 250g can be used. The mass m is preferably cylindrical, with a section S of the mass in contact with the sample being circular with a diameter of 1 .5cm.

[0043] With the procedure described above, the value k is advantageously smaller than or equal to 100kN/m, advantageously smaller than or equal to 10kN/m, advantageously smaller than or equal to 1 kN/m, advantageously smaller than or equal to 100N/m, and advantageously at least 0.1 N/m, advantageously at least 1 N/m. The value b is advantageously smaller than or equal to 2000kNs/m, advantageously smaller than or equal to 200kNs/m, advantageously smaller than or equal to 20kNs/m, advantageously smaller than or equal to 2kNs/m, and advantageously at least 1 Ns/m, advantageously at least 10Ns/m, advantageously 100Ns/m. The relaxation constant τ of the resilient material corresponds to the value bl k and is advantageously smaller than or equal to 20s, advantageously smaller than or equal to 10s, and advantageously at least 1 ms, advantageously at least 2ms, advantageously at least 20ms.

[0044] Interposed between the two resilient layers 1 14a and 1 14b are heating means, such as electrical resistance heating wires 13, which are advantageously distributed throughout the multilayer sheet 1 1 . Other heating means, such as chemical heating elements, or channels in which a heating liquid circulates, may be provided as an alternative to the electrical resistances or in addition thereto, even though these may be less suitable. Heating means 13 form part of a temperature control system, advantageously including a controller 14 and possibly an advantageously portable (electrical) energy source, such as a battery 15. The temperature control system is arranged to control and set the temperature at the inner side 1 16 of the sheet to at least 36°C, advantageously at least 36.5°C and not exceeding 40°C, advantageously not exceeding 39.5°C when in use. A temperature of at least 36°C is required for liquefying the edema (proteins) as discussed above. At temperatures above 40°C, the patient will feel a discomfort in wearing the garment 10.

[0045] Controller 14 is connected to heating means 13 through cable 16. The controller 14 is arranged to control the temperature at the inner side 1 16 of sheet 1 1 by controlling the actuation of the heating means (electrical resistances) 13. Temperature control can be effected by providing one or more temperature gauges 131 , such as thermocouples, in or at the resilient layers 1 14a, 1 14b and electrically connected to the controller 14. The controller can have a user interface, such as a control knob 141 , for adjusting the temperature as desired. The one or more temperature gauges 131 can be provided inside sheet 1 1 , e.g. between the resilient layers 1 14a and 1 14b, or alternatively at the skin facing external surface 1 17 of the multilayer sheet 1 1 (i.e. the external surface of innermost resilient layer 1 14b).

[0046] Advantageously, the controller 14 and/or energy source 15 are provided in a housing which is attached, either permanently or removably, to the multilayer sheet 1 1 .

[0047] Garment 10 may optionally be equipped with one or several pressure gauges 17, possibly electrically connected to controller 14, for measuring the static compression when the sheet is wrapped around the body part. Pressure gauge is advantageously provided at the inner side 1 16 of sheet 1 1 , and certainly internally relative to inelastic layer 1 13. Pressure gauge 17 can be provided at the skin facing external surface 1 17 of the multilayer sheet 1 1 or within the resilient layers 1 14a, 1 14b. Controller 14 may be equipped with a pressure level indicator, such as a readout screen (not shown), an indicator lamp 142 or an acoustic signalling means 143 and be configured to determine and indicate when a desired pressure level is attained. The desired pressure level can be expressed either as a minimal value, or as a range within which static pressure should fall. When pressure falls out of the range, i.e. is either too low or too high, controller may provide an indication. The static average pressure exerted by the garment 10 on the body part (skin interface) is advantageously at least 10 mm Hg, advantageously at least 30 mm Hg, advantageously at least 36 mm Hg, advantageously at least 40 mm Hg, advantageously at least 45 mm Hg. The static average pressure is advantageously 100 mm Hg or less, advantageously 90 mm Hg or less, advantageously 80 mm Hg or less, advantageously 70 mm Hg or less, advantageously 60 mm Hg or less. The desired pressure can be patient and body part-specific.

[0048] Garment 10 may optionally be equipped or combined with one or several electrodes (not shown) for providing electrostimulation, which are advantageously configured for being electrically connected to controller 14 and/or electrical energy source 15. The electrodes are advantageously attached to the skin facing external surface 1 17 of the multilayer sheet 1 1 . Alternatively, they can be provided separately of the multilayer sheet 1 1 , such that the electrodes are first suitably placed on the affected body part, after which the sheet 1 1 is wrapped around the body part. In the latter case, the electrodes are advantageously provided with connection sockets for connection to controller 14 and/or energy source 15. Provision of electrostimulation is advantageous, since it allows for stimulating the edema even when the patient is at rest. Furthermore, since the garment 10 can be portable, electrostimulation can be provided all day round.

[0049] To use the garment 10, the sheet 1 1 having suitable dimensions is wrapped around the affected body part and tightened with straps 12 until a desired static pressure level is attained, e.g. by controller 14 emitting an acoustic signal upon pressure gauge 17 measuring the desired pressure level. Thereafter, controller 14 is turned on for controlling the temperature inside the wrapped sheet 1 1 . Temperature gauges 131 measure temperature levels inside the wrapped sheet, and depending on the measured values, controller can activate the heating means 13 to increase the temperature until a desired level is attained. Controller 14 will continue to monitor the temperature inside the sheet and activate the heating means when required for maintaining the temperature at a desired level. A suitable sampling rate for temperature measurement can be 1 Hz or below. [0050] As a result of the combination of the static pressure exerted by the inelastic layer 1 13, the pressure variations induced by the resilient layers 1 14a, 1 14b on the skin in response to arterial blood pressure variations, possibly in combination with patient movement, and the temperature regime as described above, the lymphedema will decongest and swelling will be reduced. The reduction of lymphedema size will of course reduce the compressive pressure exerted by the multilayer sheet. Hence, after some time, which depends on the specific conditions, the patient will need to further tighten the straps. To help the patient in knowing the time instant when such needs to be done, the controller 14, upon receiving information from pressure gauge 17, may be configured to determine and indicate that the pressure level inside the wrapped sheet 1 1 has fallen below a predetermined threshold, e.g. by emitting an acoustic signal or by switching on an indicator lamp.

[0051] According to an advantageous aspect of the invention, in order to reduce the number of times the sheet needs to be further tightened and in order to ensure as much as possible maintenance of constant static pressure levels, garments of the invention can be further equipped with means for controlling the (static or mean) pressure at the inner side of the multilayer sheet. Such a garment 20 is represented in Figs. 3 and 4. Similarly to garment 10, garment 20 comprises a multilayer sheet 21 formed as a wrap garment and fastening means 22 with strap members 221 and rings 222. The multilayer sheet 21 comprises an inelastic layer 213 and a resilient layer 214 (only one is depicted for illustrative purposes). The resilient layer 214 is arranged at the inner side 216 of inelastic layer 213 as described above with regard to garment 10. Within resilient layer 214, or between resilient layer 214 and inelastic layer 213, a network of resistors 23 is provided as heating means. The garment 20 is further advantageously provided with temperature gauges 231 and pressure gauges 27 which may be located underneath, inside or on top (towards the inner side 216) of resilient layer 214. Temperature gauges 231 and pressure gauges 27 are electrically connected to a controller 24 which may be powered by a portable energy source 25. All the above elements may function as described above with regard to garment 10. [0052] Garment 20 further comprises a pressure control system 28 for maintaining a suitable static (or mean) compressive pressure at the skin interface during lymphedema resorption. The pressure control system 28 comprises one or more bladders 281 arranged at the inner side 216 of the inelastic layer 213, and advantageously interposed between the inelastic layer 213 and the resilient layer 214. As shown in Fig. 3, one bladder 281 may be provided which extends throughout the sheet 21 . Alternatively, a plurality of smaller, possibly interconnected bladders arranged adjacent to one another may be provided (not shown). Pressure control system 28 further comprises a fluid reservoir 282 and a pump 283 in fluid connection with the bladder 281 .

[0053] Fluid reservoir 282 is arranged at the outer side 215 of inelastic layer 213 and may be provided in a pocket 218a attached at the outside of multilayer sheet 21 . Hence, any volume change of reservoir 282 does not directly affect the compressive pressure at the inner side 216 of sheet 21 (inelastic layer 213). Like bladder 281 , also reservoir 282 can be formed of a bladder-like enclosure.

[0054] Pump 283 is interposed between fluid reservoir 282 and bladder 281 and is operable to pump fluid from reservoir 282 into bladder 281 once the sheet 21 is wrapped and fastened. Pump 283 can be a manually operated pump, which the patient or therapist can operate, advantageously following an acoustic signal or other indicator by controller 24. Alternatively, pump 283 is advantageously electrically actuated and therefore electrically connected to controller 24 and energy source 25 through cable 285. Pump 283 can be configured for two-way operation, i.e. to additionally operate in reverse mode to evacuate fluid from bladder 281 and feed it into reservoir 282.

[0055] Additionally, a bypass valve 286 and a one-way valve 287 are advantageously provided in the fluid passage between pump 283 and bladder 281 . One-way valve 287 ensures that no fluid is able to return to the fluid reservoir when pump 283 is not active. Needless to say, bypass valve 286 by-passes the one-way valve 287 for migrating fluid from bladder 281 to reservoir 282. Bypass valve 286 can be manually operated, or electrically actuated. In the latter case, bypass valve 286 is electrically connected to controller 24. [0056] Since liquids have much lower compressibility than gasses, the fluid in bladder 281 and reservoir 282 is advantageously a liquid, such as an aqueous solution.

[0057] It can be convenient to arrange the pump 283 and possibly the valves 286 and 287 at the outside of inelastic layer 213.

[0058] As the lymphedema is being resorbed, pressure control system 28 allows for adjusting the static compressive pressure without the need for loosening and re-tightening the fastening straps. Therefore, controller 24 is advantageously configured to actuate pump 283 in response to a pressure level determined by the one or more pressure gauges 27. Controller 24 may be configured to activate pump 283 each time the pressure measured by pressure gauge 27 falls below a predetermined threshold. A possible pressure control is represented in Fig. 5, which plots time evolution of mean pressure (as measured by the one or more pressure gauges 27). Pressure threshold p1 corresponds to the static pressure level set at beginning of operation, when the sheet 21 is wrapped and fastened. As the lymphedema will start being resorbed, pressure decreases until a lower pressure threshold p2. At this point, controller 24 is configured to activate pump 283 to pump fluid into bladder 281 and restore pressure level to a threshold p3. Threshold p3 may be higher or lower than, or identical to threshold p1 . It will be convenient to note that the appropriate selection of pressure thresholds p1 -p3 depends on the condition of the patient and the lymphedema and on which body part is affected. Suitable values of p1 -p3 fall in the range between 5 mm Hg and 200 mm Hg, possibly between 10 mm Hg and 200 mm Hg, and possibly between 10 mm Hg and 100 mm Hg.

[0059] When pump 283 enables two-way operation, and bypass valve 286 is electrically actuated, controller 24 may be configured to activate pump 283 for reverse operation and pump fluid out of bladder 281 into fluid reservoir 282. To that end, controller 24 may comprise a user interface button, which, when pressed, triggers opening of bypass valve 286 and activation of pump 283 in reverse mode to evacuate the bladder 281 .

[0060] To use the garment 20, the multilayer sheet 21 having suitable dimensions is wrapped around the affected body part, tightened and fastened with straps 221 through rings 222 until a desired static pressure level is attained, advantageously as indicated above. At this time, one should ensure that the bladder 281 is substantially empty or at least has a low fluid content. When bypass valve 286 is manually operated, this can be achieved by opening the valve 287 and squeeze fluid out of bladder 281 . Alternatively, bypass valve 286 and pump 283 may be activated by controller 24 upon a user input (e.g. pressing a button). Bypass valve 286 is closed subsequently.

[0061] As with garment 10, controller 24 may be configured to indicate that the desired pressure level is attained when the sheet 21 is wrapped and fastened, based on the pressure levels measured by pressure gauge 27. Thereafter, controller 24 is turned on for controlling the temperature inside the wrapped sheet 21 . Temperature gauges 231 measure temperature levels inside the wrapped sheet, and depending on the measured values, controller 24 can activate the heating resistors 23 to increase the temperature until a desired level is attained. Controller 24 will continue to monitor the temperature inside the sheet and activate the heating resistors 231 when required for maintaining the temperature at a desired level.

[0062] As the lymphedema is being resorbed due to the combination of elevated temperature and compressive pressure conditions, the overall static pressure level measured by pressure gauge 27 will start decreasing. Upon the measured static pressure level falling below a predetermined lower threshold p2, controller 24 activates pump 283 to pump fluid from reservoir 282 into bladder 281 until the pressure level measured by pressure gauge 27 is restored above the pressure threshold p3. In order to obtain this effect, it is important that the outer layer 213 as well as the fastening means 22 are inelastic, such that the volume increase of the bladder contributes maximally to compressive pressure increase at the inner side 216 of the wrapped sheet 21 . The one-way valve 287 and the bypass valve 286, which is closed, furthermore ensure that the fluid remains in bladder 281 . Controller 24 will continue to monitor the pressure level measured by pressure gauge 27 and activate pump 283 when required in order to maintain a desired compressive pressure level. [0063] At the end of operation, such as when the bladder 281 is full and cannot accept any more fluid, controller 24 may be configured to open bypass valve 286. Such end of operation can be triggered by measuring or determining the volume of fluid displaced by the pump 283, or by measuring fluid pressure within bladder 281 . Simultaneously, controller 24 may indicate, e.g. by an acoustic signal or indicator lamp, that device operation has terminated. Since at this time the fluid pressure in bladder 281 will likely be higher than in reservoir 282, fluid may naturally flow back into reservoir 282, thus depressurizing bladder 281 . Alternatively, or in addition, controller 24 may activate pump 283 in reverse mode to evacuate fluid from bladder 281 . The evacuation of fluid from bladder 281 will loosen the fit of sheet 21 around the body part, thus making unfastening easier.

[0064] The garment 20 is now ready to be reapplied around the body part by taking account of the reduced lymphedema swelling and the procedure may start over again.

[0065] It will be convenient to note that the resilient layer may be covered by a suitable (possibly exchangeable or removable) wicking layer 217, which may extend to the outer side of the inelastic layer to absorb and evacuate perspiration.

[0066] Referring to Fig. 4, the multilayer sheet 21 may be provided with pockets 218a, 218b at the outer side 215, possibly attached to the inelastic layer, for accepting the fluid reservoir 282, controller 24, energy source 25 and possibly pump 283 and valves 286 and 287. Other pockets may be provided as desired, such as to hold the electric cables and fluid tubes. As with garment 10, garment 20 is advantageously designed so as to be portable.

[0067] In order to cope with a volume reduction of the lymphedema, portions of one or more layers of the multilayer garment may be made removable, as shown in Fig. 6. The resilient layer 314 is partitioned in longitudinally adjacent portions 314', 314", etc. which, when placed adjacent one another, envelope the circumference of the body part (e.g., the limb). Each portion 314', 314" of resilient layer 314 is provided with pads 1 19 of hook and loop material, or with other fastening means for attaching the portions to the inelastic layer 1 13, which can be provided, at the side facing the body, with similar means 1 19. In such a case, the heating means are advantageously formed of a disposition of electrical resistance heating wires 13 which can be fixed to a possibly elastic liner 132 and forming a separate layer 318. Analogously to the resilient layer 314, heating layer 318 can be partitioned in longitudinally adjacent portions 318', 318", etc. Each portion 318', 318" of the heating layer 318 can be provided with similar pads 1 19 of hook and loop material, or with other fastening means for attaching each portion of the heating layer 318 to a portion of the resilient layer 314, which can be provided, at the side facing the body, with similar means 1 19. Needless to say, adjacent portions of either the resilient layer 314, or the heating layer 318, or both can be provided with suitable fasteners for attaching the portions to one another.

[0068] This provides the advantage, that when the lymphedema has reduced in volume and, hence, in circumference, one or more portions of the resilient layer 314 and possibly the heating layer 318 can be easily removed from the garment 30 in order to cope with the smaller size of the body part, in particular the lower or upper limb. In such cases, end 1 12 of the inelastic layer 1 13 can be wrapped over end 1 1 1 and there is no need to make it smaller. The garment 30 can therefore be adapted to a size or volume change of the lymphedema, increasing useful service life. It will be convenient to note that the bladder 281 of Figs. 3-4 can be partitioned similarly.

[0069] As shown in Fig. 6, it can be advantageous to place the heating layer 318 as the innermost layer, configured to make contact with the skin. Additionally, the heating wires 13 can be arranged in separate parallel electrical networks, each network being attached onto individually removable portions 318', 318" of the layer 318. One or more networks can therefore be added to or removed from layer 318 to increase or reduce the width (circumference) of the layer when one or more portions of resilient layer 314 are added or removed. Possibly, each parallel network of heating wires 13 can be controlled individually by a controller 14.

[0070] A garment constructed as in Fig. 6 was tested on a patient having lymphedema of the upper limb. The garment was composed of three parts, for the upper arm, the forearm and the wrist respectively. These parts were connected through one same inelastic layer, which was composed of a denim fabric layer made of cotton and elastane. Each part of the garment had separate resilient layers made of a foam material. A network of electrical resistance heating wires (stainless steel) with a total length of 26 m, divided into nine parallel tracks were sewn on an elastic layer which was used as liner. The elastic layer was attached to the garment through hook and loop material, so that the liner formed the innermost layer in contact with the skin. A thermistor was included on the elastic liner for measuring temperature.

[0071] The garment was wrapped around the arm and the straps tightened to attain a static pressure level of 40 mm Hg (compression) in a resting position. The heating wire network was supplied with 12V and controlled in an on-off manner such that temperature at the skin was maintained between 37°C and 39°C. The volume of the wrapped part of the upper limb was determined before wrapping the garment to be 1216 ml. The garment was removed after 30 minutes and the volume determined again to be 1 186 ml. A reduction of almost 2.5% in volume was hence obtained after only half an hour of wearing the garment.

Claims

1. Compression garment (10, 20, 30) for treating lymphedema, comprising a multi-layer sheet (1 1 , 21 ) arranged for being wrapped around a body part and one or more fasteners (12, 22) for holding the multi-layer sheet in a wrapped configuration, wherein the multi-layer sheet (1 1 , 21 ) comprises an inelastic layer (1 13, 213) extending throughout the sheet for maintaining a cross sectional perimeter of the multi-layer sheet substantially constant once wrapped and fastened, and a resilient layer (1 14a, 1 14b, 214, 318) arranged at an inner side (1 16, 216) of the multi-layer sheet such that, in use, the resilient layer is interposed between the body part and the inelastic layer, wherein the resilient layer is configured to provide resilient compression at a skin interface of the body part during use of the garment,

characterised in that the garment comprises a temperature control means (14, 24, 131 , 231 ) including heating means (13, 23) for setting a temperature at the inner side (1 16, 216) of the multi-layer sheet (1 1 , 21 ) between 36°C and 40°C, wherein the heating means (13, 23) is configured to be interposed between the inelastic layer and the body part.

2. Garment (10, 20, 30) of claim 1 , wherein the temperature control means comprises one or more temperature gauges (131 , 231 ) arranged at the inner side (1 16, 216) of the multi-layer sheet (1 1 , 21 ).

3. Garment (10, 20, 30) of claim 1 or 2, wherein the heating means are resistors (13, 23).

4. Garment (10, 20, 30) of any one preceding claim, comprising a portable energy source (15, 25) for operating the temperature control means.

5. Garment (20) of any one preceding claim, comprising a pressure control means (28) for setting a compressive pressure at the inner side (216) of the inelastic layer once the multi-layer sheet (21 ) is wrapped and fastened.

6. Garment (20) of claim 5, wherein the pressure control means (28) comprises one or more bladders (281 ) arranged between the inelastic layer (213) and the resilient layer (214), and wherein the pressure control means is operable to fill the one or more bladders with a varying amount of fluid.

7. Garment (20) of claim 6, wherein the pressure control means (28) comprises a reservoir (282) configured to contain a fluid, the reservoir being arranged at an outer side (215) of the inelastic layer and being in fluid connection with the one or more bladders (281 ), and a pump (283) configured for filling the bladder (281 ) with the fluid from the reservoir (282).

8. Garment (20) of claim 6 or 7, wherein the fluid is a liquid.

9. Garment (20) of any one claim 5 to 8, wherein the pressure control means is portable.

10. Garment (10, 20) of any one preceding claim, comprising one or more pressure gauges (17, 27) for measuring a pressure level at the inner side (1 15, 215) of the inelastic layer (1 13, 213) and a controller (14, 24) to which the one or more pressure gauges are connected.

11. Garment (10, 20) of claim 10, comprising a user interface (142, 143) coupled to the controller (14, 24) and configured to indicate a pressure level.

12. Garment (20) of claims 7 and 10, wherein the pressure control means (28) is configured to actuate the pump (283) once the controller

(24) determines that the pressure level has fallen below a predetermined first threshold (p2).

13. Garment (20) of claim 12, wherein the pump is actuated to increase the pressure level until a predetermined second threshold (p3).

14. Garment (30) of any one of the preceding claims, wherein the resilient layer (314) is partitioned in portions (314', 314"), configured to be placed adjacent one another along a circumference of the body part, wherein one or more portions are removably fastenend to the garment.

15. Garment (30) of any one of the preceding claims, wherein the heating means (13) are provided relative to the resilient layer (314) on a side facing towards the body part.

16. Garment (30) of claim 15, wherein the heating means are provided as a separate layer (318) which is removably fastened to the resilient layer (314).

17. Garment of any one of the preceding claims, wherein the garment is configured for applying a static compression level of at least 40 mm Hg to a skin interface.

18. Garment (10, 20, 30) of any one of the preceding claims, configured for wrapping a limb entirely, wherein both the inelastic layer (1 13, 213) and the resilient layer (1 14a, 1 14b, 214, 314) are configured for wrapping the limb along the entire circumference.

19. Combination of a garment (10, 20) of any one of the preceding claims comprising a portable energy source (15, 25), and one or more electrodes configured for being connected to the portable energy source and operable to provide electrostimulation.