EP1915978A1 - Device and method for regulating the humidity on the surface of a mattress-type support element - Google Patents

Abstract

The device has an envelope (1) formed by rectangular shaped upper and lower parts positioned on side of individual body (13) and an air mattress (3), respectively. The upper part (1-1) is made of material forming a barrier impermeable to air and liquid water and permeable to water vapor. The lower part is made of material permeable to water vapor. The lower part has an air injection port (4) and air discharging perforations (5) with perforated/porous zones permeable to air. An intermediate part (2) inside an inner chamber is made of a layer of non-woven fiber material e.g. polyester wadding. An independent claim is also included for a method for regulating the humidity on the surface of a mattress or cushion type support element and in vicinity of body of individual resting on element.

Description

The present invention relates to a device and method for regulating the humidity on the surface of a support element of the mattress or cushion type and in the vicinity of the body of an individual resting thereon.

This moisture can come from the body of the patient by flowing a body fluid such as by sweating, or an external source of spilled liquid. It is desirable to avoid the maceration of liquid in the soft tissues of the skin, whether it is external fluid or perspiration, because this humidification leads to a maceration which promotes the formation of bedsores and maintains infectious foci.

There is known method and device of this type consisting of injecting air on the surface or to the body of the individual, using so-called air-loss mattresses or cushions ("low-air-loss bed"). ") Consisting of compartments inflated with air under pressure. Thus, the body of the individual or the zone between the body and the support element, that is to say the mattress at which moisture can be created, is dried up by the flow of air oriented in this area. direction.

A first problem of this known device is that it can not be implemented independently of the support element, in particular the mattress and that the interruption of the injection of air inside the mattress leads to make it inoperative. Another disadvantage of this so-called air loss mattress system is that it can lead to excessive drying of the body and requires compensation of water losses by a program of hydration of the individual.

Dehumidification systems have been described in the vicinity of a patient consisting of a cover comprising a casing sandwiched between the patient and the mattress, said casing comprising an upper layer and a lower layer delimiting a chamber in which blood is circulated. air. In these systems, it is sought to dehumidify the outer surface of said upper layer on which said patient rests, at least in part by transfer of water vapor by molecular migration of water molecules through the upper layer of the permeable envelope with water vapor.

In US 5,882,349 , the lower layer of the envelope is impervious to air and water vapor, and the air is injected where appropriate into only a portion of the internal volume of said envelope by a plurality of injection orifices and is evacuated by a plurality of perforations which can be arranged on the sides of the upper layer. This dehumidification system is relatively inefficient with announced dehumidification of only 400 ml / 24h.

In US 5,926,884 a mattress cover of this type has been described in which the air is evacuated exclusively by perforations in the upper layer over the entire surface and in particular at the area covered by the patient, and the lower layer is permeable to the water vapour. The envelope thus formed between the lower layer and the upper layer both permeable to water vapor is completed by an additional underlying layer absorbing and dispersing the water vapor that may accumulate between the dehumidification device and formed and the mattress.

In these water vapor dehumidification devices, the air evacuation at least partly on the patient's side resting on the device presents risks of contamination of the envelope by penetration of liquid or other contaminant coming from the outer surface of the upper layer on which the patient rests. On the other hand, and most importantly, the dehumidification efficiencies are either relatively low or are accompanied by dehydration of the patient resulting from the excessive airflow sent near the patient.

The object of the present invention is to provide a new method and device for regulating the humidity on the surface or in the vicinity of the body of an individual resting on a mattress or cushion-type support element which does not have the disadvantages mentioned above. above and more efficient in terms of dehumidification efficiency.

More particularly, an object of the present invention is to provide a device and method that can be implemented independently of said support member and in particular on any type of air or foam mattress, or other, which has all the guarantees of safety in view of the risks of contamination of a fluid coming from the outside, and which does not require the implementation of a concomitant hydration of the patient.

Another object of the present invention is to provide a device that allows automated moisture control and not just a device for only continuously decreasing moisture such as the air loss mattress devices of the prior art.

To do this, the present invention provides a device for regulating the humidity on the surface of a support element of the mattress or cushion type and in the vicinity of the body of an individual resting thereon, comprising a casing formed by at least two parts connected together at their peripheral edges, preferably sealed by welding, defining an inner chamber, said two parts consisting of a first part intended to be disposed on the side of said body of the individual, and a second part intended to be arranged on the side of said mattress or cushion-like support element, said first part being made of a material forming a barrier impervious to air and liquid water and permeable to water vapor, said second part being constituted a material permeable to water vapor, said second part comprising at least one air injection orifice and means for evacuation of air comprising perforated or porous areas permeable to air, preferably perforations.

It is understood that said first part is non-perforated and that the air is exhausted exclusively through said second part interposed between said first part and said support member of the mattress or cushion type.

In the case of a mattress disposed horizontally on a bed, said first piece constitutes an upper piece on which the body of the individual rests and said second piece constitutes a lower piece applied to the mattress and disposed below said first piece or upper piece. .

Advantageously, the said evacuation means, preferably the said perforations, are arranged with respect to the said injection orifice (s) so as to be able to create a circulation of the air entering into the said orifice (s). chamber through said injection port and discharged from said chamber by said evacuation means, preferably said perforations, into the entire volume of said chamber when said envelope is inflated by air injected continuously under pressure by said injection port so as to create an overpressure in said chamber.

1. 1) on dispose à plat ladite enveloppe entre ledit élément de support et ledit corps d'un individu, de telle sorte que ladite première pièce soit tournée du côté du corps de l'individu et ladite deuxième pièce soit tournée du côté dudit élément de support, et
2. 2) on injecte de l'air sous pression dans ladite chambre par ledit orifice d'injection à une pression et à un débit tels que ladite enveloppe reste gonflée en surpression en dépit de l'évacuation de l'air par lesdits moyens d'évacuation et de l'appui du corps sur ladite enveloppe.

The present invention also provides a method of regulating moisture on the surface of a mattress or cushion type support member and in the vicinity of the body of an individual resting thereon, using a device according to the invention. characterized in that the steps are carried out in which:

1. 1) said envelope is disposed flat between said support member and said body of an individual, such that said first piece is turned towards the body of the individual and said second piece is turned towards the side of said support member , and
2. 2) pressurized air is injected into said chamber through said injection orifice at a pressure and a flow rate such that said envelope remains inflated at overpressure despite the evacuation of the air by said evacuation means; and the support of the body on said envelope.

It is understood that the air is injected at a pressure and at a rate such that the air inside the chamber is at an excess pressure relative to the air outside the chamber.

By virtue of the water vapor permeability properties of said first part, a transfer of water vapor takes place through said first part when a relative humidity gradient exists between the external surface of said first piece of water. the envelope and the interior of said chamber, in particular in case of maceration of a liquid or perspiration of the body or near the body between the body and said envelope, which is accompanied by a dehumidification of the surface of said first piece. When the hygrometry rate is identical on both sides of said first part, that is to say between the outside and the inside of said envelope, there is no longer a relative humidity gradient and the transfer water vapor stops automatically. But, the circulation of air inside the casing allows the water vapor to be evacuated, to evacuate it externally by said second piece. This circulation therefore favors a decrease in hygrometry inside the envelope and maintains the transfer of water vapor from the outside of the envelope to the inside of the envelope if necessary, as long as the humidity on the outside of it is greater than the relative humidity of the air inside the envelope and therefore the humidity of the air ambient injected. The fact that the moisture outside the envelope at the surface of the envelope is decreased until it reaches the relative humidity value of the injected ambient air, and that the vapor transfer of water is automatically interrupted at this time, avoids excessive dehydration of the skin tissues of said body.

In addition, because of the water vapor permeability properties of said second part, the vapor transferred inside said chamber can evacuate outwardly despite the air circulation, allowing to maintain and promote the establishment of a high relative humidity gradient between the outside of said first piece and the interior of said chamber.

According to the present invention, the fact that said second part is permeable to water vapor, and that the air is discharged exclusively through said second part, makes it possible to provide a dehumidification process exclusively by transfer of water vapor by molecular migration through the device and this, with a rate of water vapor transfer and therefore dehumidification higher than in the prior art, without the risk of excessive humidification below the device between said second part and the mattress, without risk of contamination by penetration of contamination or liquid from the upper outer surface of said first part since it is non-perforated, and finally, without requiring treatment of concomitant hydration of the patient as is the case when the air is evacuated from the upper layer towards or near the patient.

The device according to the invention has higher dehumidification performance than in the patent US 5,882,349 . In particular, the inventors have discovered that if the lower layer is impervious to water vapor, as in US'349, a moisture saturation of the interior of the envelope is rapidly established. According to the present invention, since said second piece or lower layer is permeable to water vapor and the injected air circulates throughout the chamber volume, the efficiency of the water vapor transfer from the outer surface of said first piece on which the patient rests towards the outer surface of said second piece on the mattress side, is much higher.

Furthermore, because according to the present invention, the air is discharged by said second piece or bottom layer, the water vapor transferred to the underside of said second piece or lower layer does not accumulate between it and the mattress on which it is arranged, and is evaporated by the exhaust air which is thus injected therein.

In a preferred embodiment of the present invention, the water vapor permeability of said second piece is lower than that of said first piece.

This limited water vapor permeability of said second part makes it possible to prevent the accumulation of moisture between said second part and said support member and allows the evaporation of this humidity by the sole flow of air coming from said means. exhaust air in the absence of additional air injection between said second piece and said support member.

The low performance of the system described in US'349 can also be explained by the fact that the air is not injected so as to put the total volume of the chamber under an overpressure, which limits the active vapor transfer surface. of water. Indeed, in the absence of overpressure, it does not obtain a uniform distribution in the volume portion of the chamber concerned and / or where appropriate a uniform or homogeneous circulation in the entire volume of the chamber. On the contrary according to the present invention, the establishment of an overpressure makes it possible to obtain a maximum transfer of water vapor through the upper and lower layers.

Advantageously, said second part is substantially airtight between said injection orifice and said perforated or porous air permeable zones, the latter being disposed sufficiently far from said injection orifice so that substantially all the volume of said chamber is traversed by air flowing between said injection port and said perforated or porous areas.

Advantageously, according to the invention, the ratio between the accumulated sections of the evacuation perforations and the section of the injection orifices is chosen so as to obtain a compromise between, on the one hand, the search for a flow rate of air circulating through the elevated chamber and on the other hand sufficient overpressure inside the chamber. Indeed, the pressure must be sufficient to ensure that the injected air circulates throughout the volume of the chamber, that is to say that the air is uniformly distributed throughout the volume of the room. Otherwise there is a risk that the injected air is limited to circulating inside said chamber only between said injection port (s) and those of said corresponding perforated or porous localized zones. at the passage of minimal pressure drop.

However, it is understood that the pressure must be limited so as not to destabilize the body of the individual in support of said envelope.

In practice, an overpressure of at least 500 Pa makes it possible to obtain a homogeneous air circulation in all directions and in particular in the zone below or in relation to the body of the patient.

Moreover, the upper limit of the air flow circulating in the chamber is related to the maximum rate of vacuum, that is to say to the cumulative section of the orifices that can tolerate the materials of said second piece of a point from the point of view of its mechanical resistance. This rate should not exceed 10% in general. In addition, it should be taken into account that the positive effect of the increase of the air flow on the dehumidification performance is limited by the transfer capacity of the water vapor of said first and second part layer . Beyond a certain air flow the dehumidification performance is no longer improved.

In practice a flow rate of 20 to 50 l / min provides sufficient dehumidification performance given the migration time of the water molecules for the transfer of water vapor through the polymer layers implemented as described below. .

More particularly, to obtain an overpressure of 500 to 1000 Pa with an air circulation rate of 20 to 50 l / min., The ratio of the sum of the sections of the perforations or pores of said perforated or respectively porous zones of the evacuation of the air. relative to the sum of the sections of the injection ports is at least 2, preferably 2 to 4.

The evaporation of the surface water on the patient's side is accompanied by a slight decrease in temperature which favors a decrease in sweating if necessary and offsets the increase in temperature resulting from the compression of the injected air. .

More particularly, the transfer of water vapor from said first piece is at least 750, preferably 750 to 2000 g. of water / m ² / 24h, more preferably about 1000 g./m ² / 24h and the water vapor transfer of the second part is less than 500 g. water / m ² / 24h, preferably from 300 to 500 g of water / m ² / 24h.

In a preferred embodiment, the device according to the invention comprises a spacer part inside said chamber between said first and second parts, said intermediate part being permeable to air and water vapor.

This intermediate layer promotes the spacing of said first and second parts and thus facilitates the circulation of air inside the chamber and therefore its better diffusion and better evacuation of water vapor. This insert included inside the chamber has the effect of avoiding climatic bridges between said first and second parts and to allow a better passage of air.

More particularly, said intermediate part consists of a layer of a nonwoven fibrous material, preferably polyester wadding, preferably further held in shape by a holding device, in particular a net and / or a grid of seams. quilting type.

The intermediate layer thus has an absorbing effect favoring a better distribution and spreading of the moisture and therefore a better diffusion of the moisture in the interior of said chamber, the moisture being thus more quickly evacuated by the air injected inside said chamber and inducing more efficient dehumidification.

In a preferred embodiment, said first part consists of a porous or perforated substrate which is not impermeable to water and to air, said substrate being coated on at least one face with a continuous layer of watertight polymer. liquid and air water exhibiting molecular transfer properties of water vapor.

More particularly, said second piece consists of a fabric coated on at least one of its faces with a polyurethane-type polymer layer, preferably on the outer face of the side of said physical body.

A perforated substrate such as a fabric resulting from the weaving of fibers or yarns has porosities or perforations that do not impede the passage of the water vapor transferred through the polyurethane-type polymer layer.

Polymers and textile materials of this type with water vapor transfer are known to those skilled in the art and commercially available and used especially in the garment industry for their quality of breathing the body and elimination / regulation perspiration.

This property of molecular transfer of the water vapor of said polymers results from the molecular affinity inducing an attraction of the molecules of water on the molecular chains of the polymer, in particular polyurethane, comprising hydrophilic groups, said molecules of water thus being able to walk along the polymer chain and cross the layer of said polymer.

Advantageously, said second part consists of a fabric coated on at least one of its faces with a layer of polymer permeable to water vapor, that is to say having properties of molecular transfer of the vapor of water. water, preferably on the side facing the inside of said chamber.

In a preferred embodiment, said first and second parts are connected together at their peripheral edges by welding, directly with each other or via a bonding strip coated with a polymer layer, the different polymer layers of said first and second parts and said strip, if any, being weldable to each other by heat-sealing or radiation-welding, preferably high-frequency irradiation.

More particularly, the different polymer layers are of the same chemical nature or chemical nature capable of making them weldable together, which is the case of polyurethane type polymers.

Both said pieces can be coated with polymer on both sides, and be sealed to each other directly. The two parts are preferably for economic reasons, coated with polymer on one side only. And, if at least one of the internal faces of the two parts is not coated with polymer, especially if the first part is coated with polymer on its outer face and the second part on its inner face, the edge of one of the two parts can be folded on itself so as to have its polymer-coated side towards the inside of said chamber.

In one embodiment, it is also possible advantageously to implement a peripheral bonding strip possibly folded on itself, providing the connection by welding between the two said first and second parts, said strip being itself coated on one side with less than one layer of polymer weldable with the polymer layers of both said first and second parts, the polymer layer of said strip being of the same nature impervious to liquid water, air and water vapor than that of said second piece.

Advantageously, said constituent tissues of said first and second parts are extensible fabrics in both longitudinal and transverse directions. More particularly, this property makes it possible to promote a better distribution of the weight of the body, that is to say on its larger surface area, and that the tissue conforms to the shape of the body and does not generate localized points of excessive compression of the body. can generate blockages of vascularization and pathologies that result.

Advantageously, said air evacuation perforations are disposed on the periphery of said second piece. These peripheral zones do not coincide with the central zone of the envelope on which the body is normally supported, but surround it, thus facilitating the evacuation of air by said perforations.

In a preferred embodiment, said second piece is of substantially rectangular shape and the device comprises a single injection orifice near the middle of a longitudinal edge of said second piece, said air evacuation perforations being disposed at proximity of the lateral edges and the longitudinal edge opposite that of the injection port.

Thus, the injection orifice is disposed relative to said evacuation perforations so as to circulate the air throughout the inner chamber of the casing and to evacuate to the outside as quickly as possible the moisture transferred. from the vicinity or the surface of the body towards the interior of said chamber.

In a preferred embodiment of the method according to the invention, an overpressure of the air inside said chamber is established relative to the outside of the chamber, sufficient for the air to circulate throughout the volume of the chamber. said chamber and more particularly is established an overpressure of 500 to 1000 Pa, preferably about 750 Pa, with a flow rate of air flowing in said chamber is at least 20 I / minute, preferably 30 to 50 l / minute .

Advantageously, the device according to the invention further comprises a device for injecting compressed air supplying said casing with air via an injection port.

Advantageously, in the method according to the invention, air is also injected between said second piece and said support member, preferably from the same compressed air injection device feeding said envelope by said injection port.

In a preferred embodiment, said support member consists of at least one inflatable compartment filled with air, preferably connected to the same air injection device that supplies said envelope.

The air filling said chamber can thus be derived from the same source of air as that for inflating the mattress via a device that selectively directs the air, for example a solenoid valve acting as a device. referral of a single source of air. Said solenoid valve may be an integral part of a module cooperating with the device according to the invention.

Air injection installations in an inflatable mattress have been described in particular in the applicant's patents EP 676,158 , FR 2,751,743 , FR 2 757 377 , FR 2 757 378 , FR 2 758 259 , FR 2,760,967 .

Advantageously, the device according to the invention may further comprise a remote control system, in particular by remote control, of said device for injecting compressed air.

More preferably, the device of the invention is integrated in a protective cover of a said support element of the mattress or cushion type, at least at the level of of the part of the cover intended to cover the part of the face of the support element on which at least a part of the body of an individual is intended to rest.

Advantageously, the device according to the invention may further comprise a heating device, and / or cooling of the injected, and / or air inside said chamber. Thus, it is possible to control the temperature on the outer surface of said envelope and thus in the vicinity of the body of the individual.

Other advantages and features of the present invention will become apparent in the light of the detailed description which follows and in FIGS. 1 to 3 in which.

Figure 1 shows a schematic longitudinal sectional view of an inflated air mattress covered with a protective cover incorporating the control device according to the present invention and on which a patient is based.

FIG. 2 is a diagrammatic view of the upper, lower and lower parts respectively constituting a regulating device according to the invention.

FIG. 3 is a diagrammatic cross-sectional view of a welding mode of the lower part on the upper part by means of a strip 6 forming a lateral rim 6 ₁ of a cover ending in a closing / opening device in FIG. slide 6 ₂ and also forming a flap 6 ₃ for protecting a closing / opening device 6 ₂ .

FIGS. 1 to 3 show a regulating device according to the invention comprising an envelope 1 formed from two pieces: a top piece or so-called first piece 1 ₁ and a bottom piece or said second piece 1 ₂ , of which the peripheral edges 1a and 1b are welded 1c to each other by means of a connecting strip 6 folded on itself, the weld lines 1c substantially following a rectangular contour.

The casing 1 of the regulating device according to the present invention is integrated in a protective cover 7 covering an air mattress 3. More particularly, the casing 1 forms the upper face of the protective cover, and part of the band link 6 forms lateral edges 6 ₁ of the cover of protection covering part of the sidewalls of the mattress 3, said second lower part or said second part 1 ₂ being applied directly to the mattress 3.

Said upper and lower parts are therefore substantially rectangular in shape corresponding substantially to the dimensions of the mattress. The cover comprises a closing device / opening with a toothed slide 6 ₂ peripheral along the sides or side edges of the cover covering the edge of the mattress, said closure / opening device 6 ₂ allowing the separation of a lower portion 7 ₁ cover and side edges 6 ₁ and removal of the mattress cover.

The upper part or first part 1 ₁ consists of a polyester yarn fabric coated on its outer upper surface with a polyurethane type polymer having water vapor transfer properties.

More specifically, these polyurethane-type polymers consist of polyurethane molecular chains containing hydrophilic ester groups allowing a transfer of water vapor by molecular migration of the water molecules through physico-chemical interaction with said hydrophilic ester groups. said molecular chains.

Such fabrics coated on a polyurethane face with water vapor transfer properties are sold under the trademark Dartex ^® , especially under the reference P510, having water vapor transfer properties of about 1000 g. of water / m ² / 24h (amount of water transferable through the coated fabric), and comprising a composition of 66% polyester and 34% polyurethane, and a basis weight of 130 g / m ² .

The lower piece or second piece 1 ₂ consists of a polyamide-based nylon fabric coated on one side with a layer of polyurethane permeable to water vapor, marketed by the company Dartex ^® , especially under the reference P280 with a water vapor transfer rate of about 350 g of water / m ² / 24h, a composition of 47% polyamide and 53% polyurethane, and a basis weight of 179 g / m ² .

The envelope constituted by the two lower and upper parts delimits an internal chamber 1 ₃ . Inside the chamber, insert a spacer 2 occupying substantially the entire volume of the substantially rectangular chamber, consisting of a layer of a non-woven material ₂₁ of 5 to 10 mm thick, based on polyester wadding of 160 g / m ² constituting a absorbent material permeable to air and water. This interlayer has the dual property of homogeneously distributing and diffusing the water vapor transferred inside the chamber from the outer surface of the upper part, and constituting a spacer between the lower and upper parts to avoid contact. between the two rooms.

The interlayer of nonwoven material is covered with a synthetic net 2 ₁ of tulle type polyester fibers. A peripheral seam secures the layer of the insert with said net, preferably seams longitudinal and lateral grid to stabilize the shape of the insert.

In one embodiment, air is injected so as to create an overpressure of about 750 Pa in the shell 1 relative to the outside air by establishing a flow rate of incoming air and flow of air. outgoing air balanced from 25 to 35 l / minute. To do this, the lower part 1 ₂ comprises an air injection orifice 4 in the center of about 9.5 mm and near a longitudinal edge of the lower part 1 ₂ , said air injection orifice consisting of a welded plastic connector. Ventilation perforations with a diameter of about 3 mm are regularly spaced 10 to 20 cm along the other three edges of the lower part 1 ₂ , that is to say the two transverse edges and the edge longitudinally opposite that of the injection port .. For a bed about 2m long by 90 cm wide, there were thus 48 perforations. The accumulated sections of the evacuation perforations 5 thus represent approximately twice the section of the injection orifice 4. Thus, the pressure losses associated with the restrictions on the passage of air are compensated and a balance is maintained between the inflows entering. and outgoing air flow with this flow rate of 25 to 35 l / min. and this overpressure of 750 Pa approximately the air inside the chamber relative to the outside.

The air injection orifice 4 is supplied by a compressor 8 which also supplies the air mattress 3 via a solenoid valve 9 which serves as a switch controlled by a control device 10, either for the air supply 12 of the mattress, or by the air supply 11 of the air injection port inside said chamber, depending on the measurements of a particular inflation pressure sensor mattress .

The regulating device according to the invention makes it possible to dry 500ml water spread uniformly on a cotton sheet to the dimensions of the mattress, or about 2m ² in 3:30 when said mattress is covered with a dummy simulating the body of a patient in the presence of said intermediate part 2 and 6h in the absence of said insert, the tests having been performed in an ambient atmosphere of about 40% relative humidity and at room temperature of about 25 ° C.

In FIG. 1, the welding connection of the lower 1 ₂ and upper 1 _{1 parts} is carried out by means of connecting strips 6. More specifically, a connecting strip 6 consisting of a fabric coated on one of its faces a polyurethane polymer layer and having the same properties of impermeability to air, water and water vapor and folded on itself to be welded to both the peripheral edge 1a folded over him of the upper part 1 ₁ and on the peripheral edge 1b of the lower part 1 ₂ .

The connecting strip 6 therefore comprises 2 folded parts on one another comprising from the weld 1c with the lower part 1 ₂ a lateral flange portion 6 ₁ of the mat 3 and ending with a zipper device with teeth 6 ₂ allowing opening to remove the mattress cover 7. The side flange 6 ₁ covers the sides of the mattress 3. The other part of the strip extending from the weld 1c with the upper part 1 ₁ is a flap 6 ₃ covering said lateral flange 6 ₁ and the slide fastener 6 ₂ thus protected.

Advantageously, said envelope comprises another opening / closing device, not shown, airtight and water-proof of the type of devices used to reversibly seal sachets containing food thereby opening the door. envelope and remove the insert 2 to clean it regularly.

Claims (24)

Device for regulating the humidity on the surface of a support element (3) of the mattress or cushion type and in the vicinity of the body (13) of an individual resting thereon, comprising a casing (1) formed by at least two parts (1 ₁ , 1 ₂ ) preferably interconnected at their peripheral edges (1a, 1b), preferably further sealed by welding (1c), defining an inner chamber (1 ₃ ), said two pieces consisting of a first piece (1 ₁ ) intended to be disposed on the side of said body of the individual, and a second piece (1 ₂ ) intended to be arranged on the side of said support member (3) of mattress or cushion type, said first piece being consisting of a material forming a barrier impervious to air and liquid water and permeable to water vapor, said second part being made of a material permeable to water vapor, said second part comprising least one injection port (4) and air discharge means comprising perforated or porous areas permeable to air, preferably perforations (5). Device according to claim 1, characterized in that the water vapor permeability of said second piece is less than that of said first piece. Device according to claim 1, characterized in that the transfer of water vapor from said first piece is at least 750, preferably 750 to 2000 g. of water / m ² / 24h, more preferably about 1000 g. water / m ² / 24h, and the transfer of water vapor from said second room is less than 500, preferably from 300 to 500 g. of water / m ² / 24h. Device according to one of Claims 1 to 3, characterized in that the said evacuation means, preferably the said perforations (5), are arranged with respect to the said injection orifice (s) so as to being able to create a flow of air entering said chamber (1 ₃ ) through said injection orifice (4) and discharged from said chamber (1 ₃ ) by said evacuation means, preferably said perforations (5) , throughout the volume of said chamber, when said envelope is inflated with air injected continuously under pressure by said injection port so as to create an overpressure in said chamber. Device according to one of claims 1 to 4, characterized in that said second piece is substantially airtight between said injection port and said porous or porous zones permeable to air, the latter being disposed sufficiently far from the (or) injection orifice (s) so that substantially the entire volume of said chamber is traversed by air flowing between the (s) said (s) injection port (s) and said perforated or porous areas. Device according to one of claims 1 to 5, characterized in that the ratio of the sum of the sections of the perforations or pores of said perforated or respectively porous areas of discharge of air, with respect to the sum of the sections of the orifices of injection, is at least 2, preferably 2 to 4. Device according to one of claims 1 to 6, characterized in that said perforations (5) of air discharge are disposed on the periphery of said second part. Device according to one of claims 1 to 7 characterized in that said second piece is substantially rectangular in shape and the device comprises a single said injection port (4) near the middle of a longitudinal edge of said second piece, said air evacuation perforations (5) being disposed near the lateral edges and the longitudinal edge opposite that of the injection orifice. Device according to one of claims 1 to 8, characterized in that it comprises a spacer (2) inside said chamber (1 ₃ ) between said first (1 ₁ ) and second (1 ₂ ) pieces, said insert being permeable to air and water vapor. Device according to claim 9, characterized in that said intermediate part consists of a layer of nonwoven fibrous material (2 ₁ ), preferably polyester wadding. Device according to one of claims 1 to 10, characterized in that said first piece consists of a porous or perforated substrate (1 ₁ b) not waterproof to water, said substrate being coated on to at least one side of a layer (1 ₁ a) continuous polymer, impervious to liquid water and air, and having molecular transfer properties of water vapor. Device according to Claim 11, characterized in that said first part consists of a tissue (1 ₁ b) coated on at least one of its faces with a layer (1 ₁ a) of a polyurethane polymer, preferably on the outer face of the side of said physical body. Device according to one of claims 1 to 12, characterized in that said second piece consists of a fabric (1 ₂ b) coated on at least one of its faces with a polymer layer (1 ₂ a) having properties of molecular transfer to water vapor, preferably on the side facing the inside of said chamber (1 ₃ ). Device according to one of claims 1 to 13, characterized in that said first and second parts are interconnected on their peripheral edges (1b, 1c) by welding, directly with each other or via a bonding strip (6) coated with a polymer layer, the different polymer layers of said first and second parts and said strip, if any, being weldable to each other by heat-sealing or irradiation welding, preferably irradiation high frequency. Device according to one of claims 9 to 14, characterized in that said insert (2) consists of a layer of a fibrous nonwoven substrate (2 ₁ ), held in shape by a holding device (2 ₂ ) Device according to one of claims 1 to 15, characterized in that it further comprises a device for injecting compressed air (8) supplying air to said casing (1) via said injection orifice (4). Device according to Claim 16, characterized in that the said support element (3) consists of at least one inflatable compartment filled with air, preferably connected to the same air injection device (8) as the said enclosure (1). Device according to one of claims 1 to 17, characterized in that it is integrated with a protective cover (7) of a said support element of the mattress or cushion type, at least at the level of the part of the cover intended to cover the part of the face of the support element on which at least a portion of the body of an individual is intended to rest. Device according to one of claims 1 to 18, characterized in that it further comprises a heating device and / or a cooling device of the injected air and / or air inside said chamber . Method of regulating the humidity on the surface of a support element (3) of the mattress or cushion type and in the vicinity of the body of an individual (13) resting thereon, using a device according to the one of claims 1 to 19, characterized in that the steps are carried out in which: 1) said casing (1) is disposed flat between said support member (3) and said body of an individual (13), so that said first piece (1 ₁ ) is turned towards the body of the body ( ₁ ); individual and said second piece (1 ₂ ) is turned on the side of said support member, and 2) pressurized air is injected into said chamber (1 ₃ ) through said injection orifice (4) at a pressure and a flow rate such that said envelope remains inflated at overpressure despite the evacuation of the air by said evacuation means, preferably said perforations (5) and the support of the body on said envelope. Process according to Claim 20, characterized in that an overpressure of the air inside the casing with respect to the outside is established, which is sufficient to allow air circulation throughout the volume of the said casing. bedroom. Process according to one of Claims 20 or 21, characterized in that an overpressure of the air inside the shell with respect to the outside is established from 500 to 1000 Pa, preferably approximately 750 Pa. Process according to one of Claims 20 to 22, characterized in that the flow rate of air flowing in said chamber is at least 20 l / min, preferably 30 to 50 l / min. Process according to one of Claims 20 to 23, characterized in that air is additionally injected between the said second component and the support element, preferably from the same device for injecting compressed air. (8) feeding said envelope through said injection port.

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