Protective heating sheet for a device for transporting human beings

Abstract

The invention relates to a protective heating sheet intended to be removably fastened in a transport device intended to maintain the temperature of a human being, in particular a newborn, comprising a thin-film heating element with a web of electrically conductive means and at least one layer made of an electrically insulating material intended to be connected to a power supply, wherein the electrically conductive means are made of a conductive material, the resistance of which continuously varies as a function of the temperature, at least one face of the heating element being at least partially covered with a covering layer made of a textile material. The invention also relates to a device for transporting human beings, in particular newborns, using such a sheet.

Description

Protective heating sheet for human transport device

[0001] The invention relates to the technical field of means for maintaining the temperature of human beings, used in particular during their transfer from one place to another in a medical setting.

[0002] These methods can also be used in incubators intended for newborns, which must not only avoid any bacterial contamination but also ensure a constant temperature to avoid any stress on fragile organisms.

[0003] Many means have already been proposed for heating devices receiving human beings, whether or not they are intended for their transport.

[0004] In particular, we can cite document EP3041450 which describes a transportable neonatal incubator in which heating is provided by a flow of air passing through perforations provided in the bottom of the device.

[0005] Document EP1374005 also describes an incubator comprising heating devices and fans for circulating warm air inside the incubator. This document describes means for regulating the volume of circulating air to limit evaporation losses and noise.

[0006] However, these air circulation heating devices have the disadvantage of being noisy, which contributes to the stress of newborns, causing evaporative losses, requiring the presence of sensors that require regular maintenance, and consuming a significant amount of energy. These devices are also bulky and heavy, and therefore compromise the safety of the newborn in the event of an accident.

[0007] Document WO2010 / 107724 describes an incubator in which a heating pad is placed. The pad comprises a heating element embedded in a thick layer of foam or gel. This incubator can warm a newborn without air circulation but requires the pad to be sterilized between uses, which involves a lot of handling and requires significant storage space.

[0008] The object of the invention is to overcome these drawbacks by proposing a protective heating sheet intended, in use, to be fixed in a removable manner in a device for maintaining the temperature of a human being, the temperature of which can be maintained precisely at a set value adaptable according to use, while avoiding the presence of sensors in the sheet, which makes it possible to simplify its design, and by eliminating any external supply of hot air.

[0009] This heating sheet allows a human being to be kept at their temperature by providing heat as close as possible to them, without loss. In practice, this sheet will be fixed to a padding provided in the temperature maintenance device, in particular a transport device.

[0010] This simplified design also makes the protective sheet disposable, due to the reduced manufacturing cost. However, the possibility of single use is often imperative in a medical setting.

[0011] This protective feature avoids the need to sterilize the padding of the transport device between uses.

[0012] Thus, the invention relates to a protective heating sheet designed to be fixed, in use, in a removable manner in a device for maintaining the temperature of a human being and in particular a newborn, comprising a thin-layer heating element with electrically conductive means in a sheet and at least one layer made of an electrically insulating material, intended to be connected to an electrical power supply, in which said electrically conductive means are made of a conductive material whose resistance varies continuously as a function of the temperature, at least one face of said heating element being covered at least partially with a covering layer of a textile material.

[0013] In advantageous embodiments, one and / or the other of the following arrangements is also used: the heating element of said sheet is a heating film, the electrically conductive means consisting of a metallic conductive track positioned at least on a central and main part of the sheet; the heating sheet is sterilized; the heating sheet comprises at least one fixing tab in said temperature maintenance device, connected to the main part of the sheet and projecting relative to this main part, said tab comprising a face provided with a layer of adhesive; the heating sheet is for single use; said at least one fixing tab is connected to said main part by a tear line;the heating sheet comprises a connection zone to an electrical power supply, connected to said main part and projecting relative to this main part, the conductive track extending over this connection zone and ending in two ends; the connection zone comprises means for positioning an electrical connector.;

[0014] The invention also relates to a kit comprising at least one protective heating sheet according to the invention and a power supply regulation box, intended to be connected between the heating sheet and a power supply, said box comprising means for determining the resistance of the conductive means of the heating element, deducing therefrom the temperature of the fabric at a time t Tt, comparing it to a set value Tc and regulating the power supply as a function of this comparison.

[0015] This kit may include an electrical connector between the heating sheet and the housing, this connector being removable.

[0016] The invention also relates to a device for maintaining the temperature of human beings and in particular a device for transporting newborns comprising a box delimiting an enclosure which forms a housing for a human being, the temperature of which is regulated by means of a heating sheet on which the human being can be placed, any circulation of hot air being avoided.

[0017] This simplifies the environment and maintenance of the device since any external supply of hot air is eliminated. The elimination of means generating hot air significantly reduces the weight of the device. This constitutes a considerable advantage in risk management during transport, particularly of a newborn.

[0018] Thus, the invention relates to a device for maintaining the temperature of human beings and in particular newborns, in particular a transport device, comprising two parts delimiting an enclosure, one of them forming a housing for a human being and comprising a heating sheet according to the invention, arranged in said housing.

[0019] Finally, it relates to a device for transporting human beings and in particular newborns, comprising two parts delimiting an enclosure, one of them forming a housing for a human being and comprising a kit according to the invention, said heating sheet being arranged in said housing and said box outside said enclosure.

[0020] This design allows any dangerous and bulky objects to be placed outside the enclosure.

[0021] Such a device advantageously comprises padding or mattress, on which the heating sheet can be removably fixed.

[0022] The invention finally relates to the use of a protective heating sheet according to the invention in a device, in particular for transporting, for maintaining the temperature of human beings, in particular newborns.

[0023] The invention will be better understood and other aims, advantages and characteristics thereof will appear more clearly on reading the description which follows and which is made with reference to the appended drawings in which:

[0024] is a schematic perspective and exploded view of an exemplary embodiment of a heating sheet according to the invention,

[0025] is a bottom view of the sheet illustrated in,

[0026] is a schematic perspective and exploded view of an exemplary embodiment of an electrical connector between the sheet illustrated in figures 1 and 2 and a regulation box,

[0027] is a sectional and side view illustrating the electrical connector in the closed position on the connection area of ​​the sheet illustrated in Figures 1 and 2,

[0028] is a sectional and side view illustrating the electrical connector in the closed position (in solid lines) and in the open position (in dotted lines),

[0029] is a general diagram showing the arrangement of a heating sheet and a control box in use,

[0030] is a perspective view illustrating a newborn transport device in which a heating sheet according to the invention is placed,

[0031] is a perspective view of another example of an electrical connector between the sheet illustrated in Figures 1 and 2 and a control box, shown in the open position,

[0032] is a sectional and side view illustrating the electrical connector in the closed position.

[0033] Elements common to the different figures will be designated by the same references.

[0034] The protective sheet 1 illustrated in the comprises a thin-layer heating element 10 which is covered with a layer 11 of a textile material. These two layers are fixed to each other by any means and in particular a layer of glue.

[0035] The textile material can be woven or non-woven, made from polyester or polypropylene fibers or any other material used in the medical field and in particular to make survival blankets.

[0036] In the context of the invention, this textile material will preferably be non-woven.

[0037] The weight of the material is preferably between 15 and 500 g / m2 and preferably between 200 and 300 g / m2.

[0038] The invention is not, however, limited to this embodiment and the sheet 1 could comprise a layer of textile material on either side of the heating element 10.

[0039] As also shown, sheet 1 essentially comprises four parts: a central and main part 12 of generally rectangular shape with two large sides 120 and 121 and two small sides 122 and 123, two lateral legs 13a and 13b and a connection zone 14 of elongated shape.

[0040] Each of the side legs 13a and 13b projects from a large side 120, 121 of the central portion 12 and is preferably connected to the central portion 12 via a tear line 130a, 130b.

[0041] In the example shown, these two legs are centered on each of the long sides 120,121.

[0042] On their face opposite the layer 11 of textile material, each of the tabs 13a, 13b comprises a layer 15a, 15b of adhesive protected by a film 16 which is removed when the sheet is placed and fixed in a transport device. This is preferably an adhesive which allows the sheet to be torn at the lines 130a, 130b, without leaving any residue, after removal of the side tabs. As an example, a solvent-based acrylic may be mentioned.

[0043] In the example illustrated in Figures 1 and 2, these two legs have a substantially rectangular shape.

[0044] The connection zone 14 projects relative to a small side 123 of the central part 12 and is in continuity with the latter. This zone 14 has an elongated shape.

[0045] As shown in the, the heating element 10 and the coating layer 11 have the same shape. Thus, each part of the protective sheet 1 which has just been described comprises, in thickness, a part of the heating element 10 covered by a corresponding part of the coating layer 11.

[0046] The heating element 10 is in the form of a thin layer. In the example illustrated in 1, it is a heating film comprising a metallic conductive track 100 placed flat on an insulating film 101. It has a general serpentine shape on the central part 12 and is extended by two straight portions 102, 103 in the connection zone 14. The track 100 may also comprise lateral portions in each of the legs 13a, 13b, like the lateral portion 106.

[0047] The portions 102, 103 of the connection zone 14 each comprise an end 104, 105 located at the free end 140 of the connection zone 14. These ends 104, 105 are therefore the two ends of the conductive track 100.

[0048] Near its free end 140, the connection zone 14 comprises means 141 for positioning an electrical connection means which will be described in more detail with reference to FIGS. 3 to 5. These means here consist of two perforations 141a, 141b which are made through the thickness of the sheet 1 and therefore through the heating film 10 and the layer 11 of textile material. These perforations are located between the two portions 102, 103, aligned and parallel to these portions. They are unnecessary with the connector illustrated in FIGS. 8 and 9.

[0049] The film 101 can, for example, be made of polyester and thus make the heating sheet waterproof.

[0050] The thickness of such a film is typically of the order of a few tens of microns.

[0051] This heating element is preferably flexible. This notion of flexibility is understood as the ability to adapt to three-dimensional surfaces without deterioration or malfunction.

[0052] The thickness of the heating protective sheet is generally between 0.2 mm and 3 mm and it is flexible enough to conform to the shape of a human body, or even wrinkle without losing its heating characteristics.

[0053] The conductive track 100 is made of a metallic material whose resistance varies, in the area of ​​use of the heating sheet, continuously and without asymptotic behavior, as a function of the temperature and, preferably, in a linear or substantially linear manner.

[0054] Thus, this material is different from the PTC materials used in the prior art, whose resistance increases radically as a function of temperature beyond a certain temperature threshold, set during the manufacture of the PTC material. This variation can be described as asymptotic because these materials are designed to no longer conduct electricity beyond this temperature threshold. They therefore have a switch function, unlike the heating element according to the invention.

[0055] This metallic material of the conductive track can for example be aluminum, copper, inconel or constantan.

[0056] Thanks to this feature, it is possible to regulate the power supply to the heating element, without the need for technical means, such as sensors, in the heating element itself.

[0057] For this purpose, the two straight parts 102, 103 of the conductive track are electrically connected to a control or regulation box 6 illustrated in the, by means of the electrical connector illustrated in figures 3 to 5 or in figures 8 and 9, this box itself being connected to an electrical power supply.

[0058] This box is designed to determine the temperature of the heating sheet 1 itself, at any time, and regulate the power supply based on the comparison between the measured temperature and the desired set temperature.

[0059] This set temperature is determined by the user depending on the application and the environment and the box includes means allowing the user to program it.

[0060] Reference is now made to Figures 3 to 5 and in particular to which illustrates the various constituent elements of the connector 3.

[0061] Thus, the connector 3 comprises a clamp 4 and an electric cable 5.

[0062] The clamp 4 comprises two elements 40, 41 connected to each other by means of an articulation 42. It comprises an axis 12a and a means 12b for returning the clamp to the closed position, both held in position by a nut 12c.

[0063] Each element 40, 41 comprises a first flat part 400, 410 extended by a second part 401, 411 inclined relative to the first part. The first parts are intended to together form a jaw when the clamp is closed, the second parts each forming a handle.

[0064] Figures 3 and 4 show that the first part 400 of the element 40 comprises two non-through openings 402a, 402b, while the first part 410 of the element 41 comprises two lugs 412a, 412b on its internal face opposite the openings 402a, 402b. It shows that these lugs are placed so as to be able to penetrate into the non-through openings when the clamp 4 is in the closed position.

[0065] The cable 5 comprises two electrical wires 50, 51. At one end of the cable, these wires are inserted into two parts 52, 53, respectively forming a positive terminal and a negative terminal. These parts are fixed in one of the first parts, here the first part 41. Their position is defined symmetrically with respect to those of the non-through openings 402a, 402b, so that their distance with respect to these openings corresponds to the distance between the portions 102, 103 of the conductive track and the perforations 141a, 141b of the zone 14.

[0066] At its other end, cable 5 is connected to a control box (not shown).

[0067] In use, the connector is arranged in the open position (illustrated in dotted lines on the) on the connection zone 14, so that the zone 14 rests on the element 40 and the openings 402a, 402b coincide with the two perforations 141a, 141b of the zone 14.

[0068] The clamp 4 is then closed by the operator to take the position illustrated in or the position illustrated in solid lines in. In this position, the lugs 412a, 412b of the first part 410 of the element 41 pass through the perforations 141a, 141b of the zone 14 and penetrate into the openings 402a, 402b.

[0069] In this closed position, each of the two terminals 52, 53 comes into electrical contact with one of the straight portions 102, 103 at the ends 104 and 105 of the conductive track. The heating sheet 1 is thus electrically connected to the control box, as shown in.

[0070] Figures 8 and 9 illustrate an alternative embodiment of the connector between the heating sheet 1 and the electric cable 5 connected to the housing 6.

[0071] This connector 9 comprises a female part 90 connected to the housing 6 (not shown). It forms a housing providing a slot 900 and a cavity 901 in which the two electrical wires 50, 51 of the cable 5 are fixed. The end of each wire forms an electrical contact which extends into the slot 900. Only the end 500 is shown in the figure.

[0072] The connector 9 also comprises a male part 91 corresponding to the end part of the connection zone 14. This part 91 is composed of a portion of the zone 14 near its free end 140, reinforced by a thin layer of polymer. For example, a layer of polyester with a thickness of 250 microns is sufficient to stiffen this part 91.

[0073] The latter comprises the ends 104, 105 of the conductive track 100.

[0074] Between these two ends, the part 91 comprises a hollow and elongated part 910 which opens onto the free end 140 and which engages on the stud 902 located in the part 90 when the part 91 is inserted into the slot 900 following the arrow F. Lamontre shows that the male part 91 also comprises a notch 911 on one of its edges which serves as a key and helps the user to insert this part 91 in the appropriate direction.

[0075] Indeed, the connection between the heating sheet 1 and the housing 6 is ensured by inserting the male part 91 into the slot 900 of the housing, so that the electrical contacts are supported on the ends 104, 105 to establish the electrical connection. The keying device prevents the user from inserting the part 91 in the reverse position, a position in which the electrical connection would not be established.

[0076] The disconnection between the heating sheet 1 and the housing 6 is easily achieved by removing the female part from the slot, in the opposite direction to the arrow F.

[0077] Of course, the invention is not limited to the embodiments described. Thus, the connection area of ​​the heating sheet could be longer so as to position the connector outside the device. It would also be possible to not use a connector and equip the heating sheet with electrical wires connected directly to the controller box. This latter solution would however be more expensive since the electrical wires would also be single-use.

[0078] Illustrates the heating sheet 1 which is electrically connected to the control box 6, in particular thanks to the connector 3 which has just been described with reference to figures 3 to 5.

[0079] The box 6 is electrically powered by a battery 70, itself intended to be connected to a power supply via a charger 71 of suitable voltage, for example 110V, 230V or 12V. The invention is not limited to this example and the heating sheet could be directly connected to a power supply via the control box.

[0080] Battery operation is, however, more suitable when Sheet 1 is used with a transport device.

[0081] The operation will now be described in more detail, when the sheet 1 is connected to the box, itself electrically powered by the battery 70.

[0082] Firstly, an initialization step is carried out, in which the box measures the intensity at the terminals of the heating element 10 of the heating sheet 1 and deduces the intensity (I0) and the initial resistance (R0) of the sheet.

[0083] Furthermore, the box measures the ambient temperature (T0), which corresponds to the initial temperature of the sheet, the latter also being at ambient temperature.

[0084] Once this initialization step has been carried out, the heating element 10 is supplied with electricity by the box, and after a determined time interval (t), the box again measures the intensity (It) at the terminals of the heating element, to deduce the value of its resistance (Rt) and therefore its temperature (Tt) at time t.

[0085] The box then compares the temperature at time t (Tt) to the set temperature (Tc), previously determined by the operator.

[0086] In this respect, the control box offers the operator the possibility of setting the set temperature to a value chosen within a given range, generally between 30°C and 41°C and, preferably, between 30°C and 37°C.

[0087] If this comparison reveals that the temperature at time t Tt is lower than the set temperature Tc, the box continues to supply power to the heating element.

[0088] Otherwise, the control box stops the power supply, so that the temperature of the heating sheet can drop to approach the set temperature.

[0089] Temperature monitoring is carried out at regular time intervals, generally every 0.01 to 1 second, with the measurement time lasting a few milliseconds, so as to maintain a constant temperature.

[0090] This control is very precise since it is based on a voltage measurement which gives the exact temperature of the heating sheet. This is not the case for the control obtained with known methods using heating materials which present a sudden change in resistance at a given temperature. Indeed, the characteristics of these materials can change over time and no longer provide the required precision, particularly in the medical field.

[0091] In addition, the set temperature value can be adjusted, which is not the case with these materials which are designed to self-regulate the temperature but at an invariable set temperature.

[0092] Reference is now made to which illustrates an example of a transport device for newborns.

[0093] This device 8 comprises a first 80 and a second part 81. This second part (not shown) is removable and can be fixed on the first part to delimit an enclosure. The first part 80 forms a housing for a newborn and the second part 81 is a hood, preferably transparent.

[0094] Inside this 80 housing, there is a padding or inflatable mattress 800 to ensure the comfort of the newborn.

[0095] Lamontre shows that, on this padding 800, a heating sheet 1 according to the invention is arranged. In order to hold the sheet on this padding, the film 16 present on each of the legs 13a, 13b is removed to release the layers of adhesive 15a, 15b and apply them to the padding.

[0096] Also illustrated is a connector 3 whose clamp 4 is positioned at the end of the connection zone 14 of the heating sheet 1 and whose cable 5 is connected to a control box 6. The cable passes through one of the two openings 801, 802 provided in the wall of the housing 80. This figure also illustrates the battery 7, connected to the box 6 to ensure its electrical power supply as well as that of the sheet 1.

[0097] This shows that in use, the connection area 14 allows the connector 3 to be moved away from the newborn and therefore avoids any risk of injury by contact with this part. The situation would be identical with the connector 9 illustrated in figures 8 and 9.

[0098] When the sheet 1 is removed from the padding, a break occurs at the tear lines 130a, 130b. The central part 12 and the connection zone 14 of the sheet separate from the tabs 13a, 13b which will be removed in a second step. This prevents any reuse of the sheet which is then necessarily for single use.

[0099] With the electrically powered heating sheet according to the invention, the heat is generated as close as possible to the transported patient, without any loss occurring. This is not the case when the heat is generated outside the transport device, to then be brought close to the patient.

[0100] Unlike known devices, the transport device illustrated in the figure does not require forced ventilation of hot air to ensure heating of the enclosure and thus maintaining the temperature of the newborn. Thus, the heating sheet according to the invention also prevents any stirring of dust due to air movements.

[0101] The invention is not limited to the application just described and the heating sheet according to the invention could be used in static devices, such as incubators for newborns.

Claims

Protective heating sheet intended, in use, to be fixed removably in a device for maintaining the temperature of a human being and in particular a newborn, comprising a heating element (10) in a thin layer with electrically conductive means in a sheet and at least one layer (101) made of an electrically insulating material, intended to be connected to an electrical power supply, in which said electrically conductive means are made of a conductive material whose resistance varies continuously as a function of the temperature, at least one face of said heating element being covered at least partially with a coating layer (11) of a textile material. Protective heating sheet according to claim 1, comprising at least one fixing tab (13a, 13b) in said temperature maintenance device, connected to a central and main part (12) of the sheet and projecting relative to this main part, said tab having a face provided with a layer of adhesive (15a, 15b). Protective heating sheet according to any one of claims 1 or 2, for single use. Protective heating sheet according to claims 2 and 3, wherein said at least one fixing tab (13a, 13b) is connected to said main part (12) by a tear line (130a, 130b). Protective heating sheet according to any one of claims 2 to 4, comprising a connection zone (14) to said electrical supply, connected to said main part (12) and projecting relative to this main part, the conductive track (100) extending over this connection zone and ending in two ends (104, 105). Protective heating sheet according to claim 5, the connection zone (14) of which comprises means (141) for positioning an electrical connector (3). Protective heating sheet according to one of claims 1 to 6, in which the heating element is a heating film, the electrically conductive means consisting of a metallic conductive track (100) positioned at least on said central part (12) of the heating sheet. Protective heating sheet according to one of claims 1 to 7, which is sterilized. Kit comprising at least one protective heating sheet (1) according to one of claims 1 to 8 and a control box (6) for the electrical power supply, intended to be connected between the heating sheet and an electrical power supply, said box comprising means for determining the resistance of the conductive means of the heating element, deducing therefrom the temperature of the fabric at a time t (Tt), comparing it to a set value (Tc) and regulating the power supply as a function of this comparison. Kit according to claim 9 comprising an electrical connector (3) between said heating sheet (1) and said housing (6), said connector being removable. Device for maintaining the temperature of human beings and in particular newborns, comprising two parts (80, 81) delimiting an enclosure, one of them forming a housing for a human being, and comprising a protective heating sheet according to any one of claims 1 to 8, arranged in said housing. Device for maintaining the temperature of human beings and in particular newborns, in particular a transport device, comprising two parts (80, 81) delimiting an enclosure, one of them forming a housing for a human being, and comprising a kit according to claim 9 or 10, said protective heating sheet being arranged in said housing and said box outside said enclosure. A device according to claim 11 or 12 comprising padding, said protective sheet being removably attached to said padding. Use of a protective heating sheet according to any one of claims 1 to 8 in a device, in particular a transport device, for maintaining the temperature of human beings and in particular newborns.

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