Device for supporting a human body part

Abstract

The invention relates to a device for supporting a human body part. According to the invention, the device consists of at least three pneumatic cavities maintained at different pressures, the pneumatic cavity closest to the barycentre of the device being at a pressure that is lower than that of the pneumatic cavity furthest from the barycentre of the device and the pneumatic cavities being maintained at different load pressures in order to form a pressure gradient that decreases from the pneumatic cavity furthest from the barycentre of the device to the pneumatic cavity closest to the barycentre of the device.

Description

SUPPORT DEVICE FOR A PART OF THE HUMAN BODY

[0001] The present invention relates to a device for supporting a part of the human body in a fixed position. Although not limited to this type of application, the invention will be described more particularly with reference to the case of patients in a hospital setting when they must keep at least part of their body in a fixed position, supported by a support.

[0002] Other types of applications include, for example, seating for people who have to remain immobilized for long periods in armchairs, or, for example, seating for wheelchairs.

[0003] In many situations, hospitalized patients, whether in a room or in the operating room, must remain lying still. Regardless of the mattress's quality, the pressure exerted by the patient's weight between bony prominences and pressure points on the skin and flesh leads to necrosis or pressure sores. These skin lesions result from prolonged pressure on certain parts of the body, causing tissue ischemia and significant skin damage.

[0004] Such discomfort can indeed be observed after surgeries lasting several hours when the patient must be held in a fixed position on a few points of support. This discomfort can also occur in patients who are hospitalized for extended periods or in individuals with very limited mobility.

[0005] Among the various positions that can cause pressure sores, the supine position, in which the patient lies on their back, presents particular risks. This position results in prolonged pressure on certain areas of the body, such as the sacrum, heels, and shoulder blades, thus promoting the development of these painful and potentially dangerous lesions.

[0006] One technique currently used in hospitals involves the use of foam or gel wedges to improve pressure distribution.

[0007] It turns out that these devices are cumbersome to store and can still lead to bedsores due to the pressure exerted on the skin and flesh.

[0008] US patent 2009056030 describes a hospital bed mattress combined with an air circulation system that ventilates the skin surface of patients lying in bed to reduce the risk of pressure sores by removing heat and moisture. It is a complex and expensive device.

[0009] US document 2017065473 describes a more economical inflatable wedge system for supporting a patient, whose inflation varies regularly and which also provides for ventilating the skin surface.

[0010] Although more economical, this latter system is not considered sufficient to prevent the risk of pressure sores and remains limited to certain uses.

[0011] The inventors have thus set themselves the mission of proposing a support device for any part of the human body, which is simple to implement, has limited manufacturing costs, and reduces the risk of lesions or bedsores.

[0012] This goal has been achieved according to the invention by a support device for a part of a human body, said device being made up of at least three pneumatic cavities maintained at different pressures, the pneumatic cavity closest to the center of gravity of the device being at a lower pressure under load than that of the pneumatic cavity furthest from said center of gravity of the device and the pneumatic cavities being maintained at different pressures under load to form a pressure gradient decreasing from the pneumatic cavity furthest from said center of gravity of the device to the pneumatic cavity closest to said center of gravity of the device.

[0013] For the purposes of the invention, a load pressure corresponds to the pressure measured when the part of the human body is in contact with the support device.

[0014] For the purposes of the invention, the barycenter is the center of gravity of the device.

[0015] Advantageously according to the invention, the pneumatic cavity closest to said center of gravity of the device is maintained at a pressure under load of less than 10 millimeters of mercury (mmHg).

[0016] The support device for a part of a human body thus described according to the invention makes it possible to support said part of the human body in a desired position while reducing the risk of pressure sores.

[0017] The inventors have been able to demonstrate that the distribution of pressures between the cavities proposed by the invention allows for a better distribution of pressures on the part of the human body to be worn, for example the sacrum area when positioned in supine position.

[0018] The inventors have indeed shown that by superimposing the at-risk area of ​​the human body with the center of gravity of the device, the risk of pressure sores is greatly reduced while ensuring comfort and support for the affected part of the human body.

[0019] According to a preferred embodiment of the invention, each of the pneumatic cavities includes an inflation valve.

[0020] The valves associated with each of the cavities thus ensure that the pressure required for each of the cavities is maintained under the effect of the weight of the part of the human body that comes into contact with it, and allow for the possible control of the different pressures during the use of the device.

[0021] The valves are advantageously positioned to ensure accessibility during use while preventing contact with the human body. They may also be offset and grouped together to facilitate pressurization of the cavities.

[0022] The valves are advantageously still flap valves to ensure the best possible sealing.

[0023] According to a first embodiment of the invention, the center of gravity of the support device for a part of a human body is advantageously located within the pneumatic cavity closest to said center of gravity of the device and maintained at the lowest pressure under load.

[0024] According to another embodiment of the invention, the center of gravity of said device is outside any cavity. This is particularly the case when the support device for a part of a human body has a hollowed-out area around its center of gravity. In such an embodiment, the cavity exhibiting the lowest pressure is positioned around the at-risk area of ​​the human body, the latter being subjected to no pressure and without any contact.

[0025] According to one embodiment of the invention, the support device for a part of a human body consists of at least one sheet of thermoplastic polymer forming at least one cavity preferably having a tensile modulus of elasticity at 10% elongation less than 20 MPa, said at least one sheet of thermoplastic polymer being folded and welded on its edges.

[0026] According to another embodiment of the invention, the support device for a part of a human body consists of at least two sheets of thermoplastic polymer preferably having a tensile modulus at 10% elongation of less than 20 MPa, said at least two sheets of thermoplastic polymer being heat-welded edge to edge.

[0027] The measurements of the modulus of elasticity under tension at 10% elongation are carried out according to the DIN 53504 standard.

[0028] The heat sealing of thermoplastic polymer sheets can be carried out in particular by ultrasound, conduction or high frequency.

[0029] Preferably, the thermoplastic polymer sheet(s) have a tensile modulus at 10% elongation of less than 10 MPa.

[0030] Preferably, the thermoplastic polymer sheet(s) should have a thickness of less than 1 mm and preferably even less than 0.5 mm.

[0031] Such a material allows, as is known, the simple fabrication of a component with a sealed, pressurizable cavity. A particularly suitable material is thermoplastic polyurethane. Heat sealing can be achieved by locally heating the sheet to its melting temperature. The sheet's rigidity helps reduce the risk of pressure sores when it is in contact with the skin. Heat sealing can be performed using ultrasound, conduction, or high frequency.

[0032] The choice of this thin and deformable material also allows it to conform to the supported part of the human body and thus optimize the contact surface between the support device and the part of the human body.

[0033] Furthermore, manufacturing the support device for a part of the human body from a heat-weldable material allows for relatively precise shaping. Heat welding makes it possible to define the shape of the support device with such precision that it can optimally rest on selected areas of the body part. Indeed, the inventors have demonstrated that they could to obtain shapes to support the chosen areas of the human body part and thus ensure its support under the pressure in load defined according to the cavity.

[0034] When the support device consists of at least two sheets of thermoplastic polymer, the sheet(s) not in contact with the skin are advantageously reinforced. This reinforcement can be fiber-based or fabric-based and results in a thermoplastic polymer sheet that is stiffer than one with a tensile modulus of elasticity at 10% elongation of less than 20 MPa.

[0035] As explained previously, the support device can be made with one or more sheets of thermoplastic polymer.

[0036] In the case of a folded thermoplastic polymer sheet, or two thermoplastic polymer sheets, the support device can take the form of a cushion, with the two thermoplastic polymer sheets heat-sealed around their perimeter. Additional heat sealing can also create a recess, resulting in a buoy-like shape.

[0037] The support device for a part of the human body can also take the form of a tube. It can be made from a sheet of thermoplastic polymer heat-sealed along its length to form a tube. Its ends are either heat-sealed to form a pyramid-shaped form, or closed by two additional sheets of thermoplastic polymer heat-sealed to close off said ends.

[0038] According to one or the other embodiment of the device made from at least one sheet of thermoplastic polymer or at least two sheets of thermoplastic polymer, the pneumatic cavities can each be made from at least one sheet of thermoplastic polymer or at least two sheets of thermoplastic polymer, said pneumatic cavities being associated with each other by means of connection.

[0039] Examples of such means of connection include welding, or separable means of connection.

[0040] Separable fastening means include, for example, Velcro® type devices, each part of which is fixed to the surface of a pneumatic cavity by welding, sewing or any other suitable means.

[0041] Separable fastening means can also be any other type of fastening system that is advantageously simple to use, such as, for example, detachable zipper fasteners or any type of quick-release buckle system.

[0042] According to either embodiment of the device made from at least one sheet of thermoplastic polymer or at least two sheets of thermoplastic polymer, the pneumatic cavities can be created by at least one wall formed of a sheet of thermoplastic polymer welded, along its entire length, to the inner surface of at least one sheet of thermoplastic polymer. Such a wall thus forms two cavities of said device.

[0043] It is still possible to create the different pneumatic cavities, according to one or the other embodiment of the device made from at least one sheet of thermoplastic polymer or at least two sheets of thermoplastic polymer, by creating welds of a sheet of polymer on itself or between two sheets of polymer to subdivide the volume initially created by said at least one sheet of thermoplastic polymer.

[0044] An advantageous embodiment of the invention provides that at least a portion of the surface of said device coming into contact with said part of a human body is covered with a "3D spacer" fabric.

[0045] For the purposes of this invention, "3D spacer fabrics" are three-dimensional fabrics of the type "XD Spacer Fabrics" marketed by Baltex or "3MESH SPACER FABRIC" marketed by Muller, which are already used in medical applications. These three-dimensional fabrics offer the advantage of providing ventilation to the surface of the human skin in contact with the support module. Such fabrics are described, for example, in US patents 2018187348, EP 1347087, EP 2408957, and WO 2012098130.

[0046] Such "3D spacer" fabrics can be woven or knitted, consisting of two layers connected by one or more filaments. These filaments can be made of various materials: polyester, polyamide, polypropylene, or cotton. They can be used in their raw form, or coated or coated to modify the texture or limit the growth of viruses or bacteria. These filaments possess a certain resilience conferred by their diameter, which exceeds 30 mm. microns, preferably greater than 100 microns and with a density and pattern adapted to withstand compression forces; they thus give the "3D spacer" fabric a buckling stress, that is to say a resistance to compression or resistance to buckling of these filaments.

[0047] Advantageously, the "3D spacer" fabric exhibits a buckling stress greater than the inflation pressure of the pneumatic cavity.

[0048] In the context of this invention, the buckling stress of the fabric is the stress perpendicular to the median plane of the fabric that causes the filaments connecting the two surfaces to buckle. Beyond this stress, the two fabric surfaces come very close together and can no longer perform their ventilation function.

[0049] The average plane of the fabric corresponds to the surface of the fabric when it is laid flat.

[0050] The buckling stress is measured according to ISO 3386-1.

[0051] Even more advantageously, the buckling stress of the "spacer 3D" fabric is less than 0.2 bar.

[0052] Such buckling constraints make it possible to combine ventilation of the human body's skin and supportive comfort.

[0053] According to a preferred embodiment of the invention, the thickness of the "3D spacer" fabric is less than 10 mm.

[0054] Preferably according to the invention, the air permeability of the "3D spacer" fabric is greater than 1000 l / dm² 2 xmin under a pressure of 1 mbar.

[0055] The permeability of the tissue is measured according to the ISO 9237 standard.

[0056] The presence of a "3D spacer" fabric, advantageously presenting characteristics such as those described above, in contact with the skin of the supported body part allows for the evacuation of moisture and heat and thus helps to preserve the skin that comes into contact with the support device.

[0057] According to one embodiment of the invention, the "3D spacer" fabric is provided to be removable and separable from the first element so that it can be properly cleaned and / or changed regularly.

[0058] It is also possible to provide a cover made with the "3D spacer" fabric, enveloping the entire support device forming the pneumatic cavity and intended to come into contact with the part of the human body. Alternatively, in the case of the presence of a second element, a cover enveloping the entire support device. In all cases, these covers are designed to be removable for proper cleaning and / or regular replacement.

[0059] Advantageously, according to the invention, at least a peripheral portion of the surface of said device that comes into contact with said part of a human body is covered with an adhesive compatible with human skin. In accordance with this embodiment of the invention, the adhesive is at least partially associated with the pneumatic cavity maintained at the highest pressure under load. This embodiment of the invention will help reduce the risk of pressure ulcers by preventing any risk of displacement of the support device.

[0060] Another embodiment of the invention further provides that at least one pneumatic cavity includes an internal channel opening onto the external surface of the device through at least one opening. Such a channel is, for example, a tube of any cross-section whose shape is designed to fit into a cavity through an opening, the cavity remaining airtight. Such a channel may be designed to accommodate an absorbent material such as cotton, sponge, etc., a portion of which comes into contact with the skin. The presence of this absorbent material can absorb and store any bodily fluids and thus further help to limit the risk of pressure ulcers. Such fluids can indeed promote the formation of pressure ulcers.

[0061] Preferably according to the invention, the inflation of the pneumatic cavities of the support device for a part of a human body is advantageously carried out with an inert and / or purified gas to avoid any additional risk of infection in the event of an accident on one of the modules leading to a leak, particularly when used in a hospital setting.

[0062] The invention as described above, in addition to its advantages in reducing the risk of pressure ulcers, offers several other benefits, particularly those related to the inflatable nature of the components of a support device for a part of the human body. Indeed, the use of inflatable components allows their volume to be reduced when not in use or before use, thus facilitating storage.

[0063] Another advantage of the body support device described herein lies in its manufacturing costs, primarily due to the materials used. Indeed, the low cost of producing the support device according to the invention allows for the availability of devices in various sizes and shapes, enabling better adaptation to the specific body part being supported, or to accommodate different body sizes and builds. This range of sizes for the support device also allows for optimization of the positioning of the support points on the body part being supported.

[0064] Combined with the gain in volume and the low cost of the support system, it becomes possible to store a large number and variety of these elements and thus have at any time the model best suited to the situation, particularly in terms of variety of shapes.

[0065] Other advantageous details and features of the invention will become apparent from the description of the examples of embodiments of the invention with reference to figures 1 to 4 which represent: figure 1, a schematic representation of a first embodiment of a support device according to the invention, figure 2, a schematic representation of a second embodiment of a support device according to the invention, figure 3, a schematic representation of a third embodiment of a support device according to the invention, figure 4, a schematic representation of a fourth embodiment of a support device according to the invention.

[0066] The figures are not shown to scale to simplify understanding.

[0067] In Figure 1, the support device 1 is made from two sheets of thermoplastic polyurethane forming the main surfaces 2 of the device, one of which is in contact with the skin. These two sheets of thermoplastic polyurethane are commercially available under the name Tuftane TFL-1E and have a secant elongation modulus of 9.8 MPa at 10% elongation. They are cut into discs and heat-sealed at their edges. A wall made of the same sheet of Thermoplastic polyurethane is welded to each of the inner faces of the first two thermoplastic polyurethane sheets to form three cavities 3, 4 and 5. As mentioned previously, it is also possible to form the three cavities by welding the inner faces of the two thermoplastic polyurethane sheets to each other along a circular line 6, advantageously concentric with the peripheral lines 7 and 8. Point 9 symbolizes the barycenter or center of gravity of the support device 1.

[0068] During use, cavity 3 is maintained at a lower pressure than cavity 4, which is itself maintained at a lower pressure than cavity 5, creating a pressure gradient where the pressure decreases from cavity 5 to cavity 3. Each of the cavities 3, 4, and 5 is pressurized via valves (not shown in the figures) located on each cavity. Each valve can be positioned at the end of a tube connected to a cavity, allowing easy access for inflation to the desired pressure. These valves, or the tubes connecting them, are designed to avoid contact with the skin.

[0069] When setting up the support device, the most sensitive part of the human body, i.e. the area where the bony protrusion that can cause a pressure sore is most prominent, is centered on the center of gravity of the support device.

[0070] Figure 2 illustrates a schematic representation of a second example of a support device for a part of a human body 21. This device 21 has three parallel cavities 22, 23, 24. Like the first device 1, device 21 can be made from two initial sheets of thermoplastic polyurethane welded around their periphery, and two further sheets of thermoplastic polyurethane welded along their entire length to each of the inner faces of the first two thermoplastic polyurethane sheets. Device 21 thus forms a cushion with three cavities 22, 23, 24. Point 25 represents the barycenter or center of gravity of device 21.

[0071] When using device 21, cavity 23 is maintained at a pressure under load less than 40 mm of mercury in accordance with the invention and lower than those of cavities 22 and 24, the latter being maintained at an identical pressure.

[0072] As in the previous case when using the support device 21, the barycentre 25 is centred on the area of ​​the part of the human body most susceptible to the appearance of pressure ulcers.

[0073] Figure 3 illustrates a schematic representation of a third example of a support device for a part of a human body 31. This device 31 comprises three cavities 32, 33, 34 arranged around one another. The support device 31 has the shape of a cushion, the projection of each cavity onto a plane forming approximately a parallelogram. Like the previous devices 1 and 21, device 31 can be made from two first sheets of thermoplastic polyurethane welded at their periphery, and a sheet of thermoplastic polyurethane welded along its entire length to each of the inner faces of the first two thermoplastic polyurethane sheets to form a partition separating the three cavities 32, 33, 34. Device 31 thus forms a cushion comprising three cavities 32, 33, 34. Point 35 symbolizes the barycenter or center of gravity of device 31.

[0074] When using device 31, cavity 32 is maintained at a pressure under load less than 40 mm of mercury in accordance with the invention and less than that of cavity 33, which is itself less than that of cavity 34.

[0075] As in previous cases when using the support device 31, the barycentre 35 is centred on the area of ​​the part of the human body most susceptible to the appearance of pressure ulcers.

[0076] Figure 4 illustrates a schematic representation of a fourth example of a support device for a part of a human body 4L. This device 41 comprises four cavities 42, 43, 44, 45 arranged around each other. Point 46 symbolizes the barycenter or center of gravity of the device 31.

[0077] When using the device 41, the cavity 42 is maintained at a pressure under load of less than 40 mm of mercury in accordance with the invention and less than that of the cavity 43, itself less than that of the cavity 44, itself still less than that of the cavity 45, the pressure under load of the cavity 45 being the highest.

[0078] The cavity 45 is not present around the entire periphery of the cavity 44, leaving a free zone 48 into which a channel 47, formed within the cavity 45, opens. This channel 47 is made with a tube formed, for example, with a sheet of thermoplastic polyurethane. Within this channel 47 is inserted a drain 49, formed for example of cotton, which is visible outside the channel 47 in the area 48.

[0079] When the support device 41 is in contact with the human body, the drain 49 comes into contact with the skin at the level of this area 48 and allows to absorb and retain any bodily fluids present at the level of this part of the human body and thus best prevent their presence near the sensitive area where the risk of pressure ulcers is high.

[0080] Tests were carried out with a support device as shown in Figure 1.

[0081] This support device is designed to be positioned at the level of the sacrum, with the individual in a supine position.

[0082] Before its installation, the support device is partially filled with inflation gas in order to detach the walls of the pneumatic cavities.

[0083] The support device is put in place and the pneumatic cavities are brought to and maintained at the desired pressures under load.

[0084] The pressure in cavity 3 is equal to 40 mmHg.

[0085] The pressure in cavity 4 is equal to 75 mmHg.

[0086] The pressure in cavity 5 is equal to 95 mmHg.

[0087] These pressures are determined in this scenario for optimum support to reduce the risk of pressure ulcers and ensure pneumatic support.

[0088] The examples presented should not be interpreted as an exhaustive list. The shapes of the devices may vary, their method of implementation may differ, and the number of cavities in a device may be greater.

Claims

DEMANDS 1 - Support device for a part of a human body characterized in that said device consists of at least three pneumatic cavities maintained at different pressures, in that the pneumatic cavity closest to the barycenter of the device is at a lower pressure under load than the pneumatic cavity furthest from said barycenter of the device and in that the pneumatic cavities are maintained at different pressures under load to form a pressure gradient decreasing from the pneumatic cavity furthest from said barycenter of the device to the pneumatic cavity closest to said barycenter of the device. 2- Support device for a part of a human body, according to claim 1, characterized in that the pneumatic cavity closest to said center of gravity of the device is maintained at a pressure under load of less than 10 millimeters of mercury (mmHg). 3- Support device for a part of a human body, according to one of claims 1 or 2, characterized in that each of the pneumatic cavities has an inflation valve. 4- Support device for a part of a human body, according to any one of claims 1 to 3, characterized in that the center of gravity of said device is outside any cavity. 5- Support device for a part of a human body according to one of the preceding claims, characterized in that it consists of at least one sheet of thermoplastic polymer forming at least one cavity preferably having a tensile modulus of elasticity at 10% elongation of less than 20 MPa and in that said at least one sheet of thermoplastic polymer is folded and welded on its edges. 6- Support device for a part of a human body according to one of the preceding claims, characterized in that it is made up of at least two sheets of thermoplastic polymer forming at least one cavity preferably having a tensile modulus of elasticity at 10% elongation of less than 20 MPa and in that said at least two sheets of thermoplastic polymer are welded edge to edge. 7- Support device for a part of a human body according to one of the preceding claims, characterized in that said at least three pneumatic cavities are connected together by means of connection. 8- Support device for a part of a human body according to any one of claims 1 to 6, characterized in that said at least three pneumatic cavities are created by at least one wall formed of a thermoplastic polymer sheet welded, along its entire length, to the internal surface of at least one thermoplastic polymer sheet forming said at least three cavities of said device. 9- Support device for a part of a human body according to one of the preceding claims, characterized in that at least a part of the surface of said device coming into contact with said part of a human body is covered with a "3D spacer" fabric. 10 - Support device for a part of a human body according to any one of the preceding claims, characterized in that at least a peripheral part of the surface of said device coming into contact with said part of a human body is covered with an adhesive compatible with human skin. 11 - Support device for a part of a human body according to one of the preceding claims, characterized in that at least one pneumatic cavity has an internal channel opening through at least one opening onto the external surface of the device.

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