Device for detecting the posture of a person on a bed

Abstract

A device (100) for detecting the posture of a person on a bed comprises a flexible support (1) having a first end (101) and a second end (102). The flexible support (1) comprises a first part (11) in which a plurality of pressure sensors (2) are arranged, and a second part (12) in which a plurality of pressure sensors (2) are arranged, the first part (11) being closer to the first end (101) than the second part (12), and the second part (12) being closer to the second end (102) than the first part (11). The flexible support (1) also comprises a third part (13), located between the first part (11) and the second part (12), said third part (13) being elastic, such that it can deform elastically, allowing an increase in the distance between the first part (11) and the second part (12).

Description

[0001] DESCRIPTION

[0002] DEVICE FOR DETECTING THE POSTURE OF A PERSON ON A BED

[0003] TECHNICAL FIELD

[0004] The invention is comprised in the field of devices and systems for detecting the position of a person on a bed, for example, for generating alerts on the risk of falling.

[0005] BACKGROUND

[0006] Accidental falls of elderly people or patients with reduced mobility lying in hospital beds represent a considerable risk. To that end, and for other reasons (for example, to check that a person changes his / her posture frequently enough, for example, to prevent skin lesions), it may be important to be able to detect the posture or position of a person on a bed.

[0007] Traditional fall prevention systems use a variety of approaches, from side bars on beds to patient movement alarms. However, these systems may be insufficient or even counterproductive. Side rails may cause injuries due to entrapment, and movement alarms may generate false alarms. Furthermore, these systems often do not provide detailed information about the position of the patient on the bed, which is useful for effectively preventing falls.

[0008] Advances in this field allow the use of pressure sensors, arranged on a mat, which can continuously and accurately map the weight distribution and position of the patient's body. For example, international patent application WG-2004 / 006768-A1 describes a mattress comprising pressure sensors throughout its entire surface, capable of monitoring the position of a person on the mattress.

[0009] Other solutions, such as international patent application WO-2019 / 103620-A2, propose the use of radars located in the room where the patient is lying on the bed. Said radars constantly monitor the position of the person on the bed or anywhere else in the room.

[0010] Furthermore, the integration of data analysis and machine learning algorithms with these sensor systems allows for a more sophisticated analysis of the patient’s movement and behavior patterns. These algorithms can learn to distinguish between normal movements and those that represent a risk, significantly reducing the number of false alarms and improving response to critical events. For example, United States patent application US- 2019 / 110761 -A1 describes the use of movement patterns in pressure data measured by pressure devices in a mattress to determine the probability of a patient on the bed falling off same.

[0011] Although the use of pressure sensors can provide useful information about the position of a person on the bed, for example, for determining the risk of that person falling off the bed in order to activate an alarm, for example, it has been found that there are many practical problems. For example, movement of one or more sensors from their original position on or below the mattress can lead to incorrect information about the position of the person, generating, for example, false alarms, or an absence of alarm in a critical situation. Similarly, the presence of a large number of sensors can lead to wiring problems, due to the need to connect the sensors to a signal and data processing unit.

[0012] DESCRIPTION OF THE INVENTION

[0013] The invention relates to a device for detecting (for example, for enabling the monitoring of) a posture of a person on a bed. The device comprises a flexible support having a length and a width, the flexible support having a first end and a second end, with the length being the distance between the first end and the second end. In general, the length is greater than the width, and the idea is to place the flexible support on the bed base of a bed such that the first end corresponds with the part of the flexible support closer to the headboard end of the bed, and the second end corresponds with the part of the flexible support closer to the opposite end of the bed. The flexible support may have a rectangular or approximately rectangular configuration, for example, a rectangular configuration but with corners that are rounded, beveled, etc. The fact that the flexible support is flexible allows the flexible support to be folded, for example, in order to facilitate storage and transport, etc. The flexible support can also have areas with a smaller width, as will be discussed below.

[0014] The flexible support comprises a first part in which a plurality of pressure sensors are arranged, and a second part in which a plurality of pressure sensors are arranged. The first part is closer to the first end than the second part, and the second part is closer to the second end than the first part.

[0015] The flexible support also comprises a third part, located between the first part and the second part. The third part is elastic, such that it can deform elastically, allowing an increase in the distance between the first part and the second part. In this context, references to “first”, “second”, and “third” parts do not necessarily imply that the parts are clearly differentiated with respect to one another, for example, in terms of the materials forming same or in terms of other aspects of their configuration. Rather, these terms are used to refer to three different areas or regions, in the sense that the first part and the second part are parts or regions or areas in which pressure sensors are arranged, and the third part is an elastic area or elastic part located between the first part and the second part. However, in some embodiments, they are clearly differentiated parts, for example, in terms of their configuration and / or in terms of the materials forming the respective parts. For example, in many embodiments, the first part and the second part are not elastic, or are less elastic than the third part.

[0016] The presence of the third elastic part allows, for example, the flexible support with the sensors to be able to be placed on the bed base of a fold-down bed, i.e., on a bed base in which, for example, a reclinable part associated with the headboard part of the bed can be reclined with respect to the contiguous part of the bed base, for example, so that a person on the bed can move from a position in which he / she is stretched out horizontally to a reclined position, typically with his / her torso at an angle to his / her legs, for example, to make it easier for the person to get out of the bed in order to eat, read, etc. The third part of the flexible support can then be located in correspondence with the pivoting axis of the reclinable part of the bed base, and thereby be elastically stretched along the bed base and the mattress when part of the bed base is moved by pivoting, for example, with the consequence that the bed base is lengthened as a result of the pivoting of the reclinable part of the bed base about a point of rotation shifted with respect to the pivoting axis. In this way, the risk of the sensors moving in relation to the upper surface of the bed base as a result of pivoting can be reduced, for example.

[0017] “Elastic” is understood to mean that the third part is capable of recovering its initial length, i.e., its initial extension in the longitudinal direction, after being deformed by lengthening the initial length thereof.

[0018] The elastic material of the third part can be a simple material made up of a single component or a composite made up of several materials, that confer elastic properties. One example of a simple elastic material can be an elastomer or a woven material such that they confer elastic properties thereto. One example of composite can be a non-elastic material intertwined with elastic fibers. In addition to being elastic, the third part can be flexible. The attachment between the third part and the first part can be differentiated or homogeneous without any attachment line visible to the naked eye, depending on the materials making up the third part and the first and second parts. Furthermore, the material making up the first and second parts of the flexible support can be different from one another, and / or different from the material making up the third part.

[0019] In some embodiments of the invention, the third part is configured to be able to stretch elastically, i.e., without plastic deformation, at least 5 cm, for example, 8 or 10 cm or more parallel to a longitudinal axis of the flexible support.

[0020] In some embodiments of the invention, the width of the flexible support is constant along the flexible support, between the first end and the second end. In other words, in many embodiments, the first part, the second part, and the third part have the same width. For example, the flexible support may have a substantially rectangular configuration.

[0021] In some embodiments of the invention, the third part consists of at least one attachment band between the first part and the second part, with a width smaller than the width of the first part and than the width of the second part (12). In some embodiments, the third part, acting as a bridge between the first part and the second part, may be narrower than said first and second parts, and may consists of one or more bands, that are more or less narrow, attaching the first part and the second part and allowing, due to their elasticity, the first part to be separated more from the second part, for example, when folding the bed base, as discussed above.

[0022] In some embodiments of the invention, the third part has an extension of at least 10 cm (for example, at least 15 or 20 cm or more) in a longitudinal direction, i.e., according to an axis x parallel to the longitudinal extension of the device, i.e., the axis going from one end of the flexible support to the other.

[0023] In some embodiments of the invention, the second part comprises a first sub-part and a second sub-part separated by a fourth part, the fourth part being elastic. This fourth elastic part can perform the same function as the third elastic part, in correspondence with another articulation of the bed base, for example, in an articulation located in correspondence with the knees of the user.

[0024] In some embodiments of the invention, the first part and the second part are made of a first material, and the third part is made of a second material, different from the first material. In this context, the term “material” should be understood in a broad sense, including mixtures or compositions of different materials. It refers to the material or to the mixture of materials, for example, woven or non-woven materials, forming the main part of the first, second, and third parts, respectively. The use of different materials allows, for example, using materials with different elasticity characteristics, for example, to minimize the risk of the sensors moving when, for example, the bed base is reclined. In other embodiments, the first, second, and third parts can be made of the same material, for example, they can be formed by a single elastic piece.

[0025] In some embodiments of the invention, at least the first part and the second part each comprises at least one upper layer and a lower layer, between which the respective pressure sensors are located. For example, the flexible support can be made up of an upper layer and a lower layer, and the pressure sensors are located between said layers. In other variations of the flexible support, the flexible support is made up of a single layer of flexible material comprising an upper face and a lower face. The pressure sensors can be embedded inside the flexible support. In other embodiments, the sensors are superimposed on one of the faces of the flexible support.

[0026] In some embodiments of the invention, each pressure sensor has a surface area of at least 100 cm2, for example, 200 cm2, 300 cm2, 400 cm2’ or more. The sensors can be substantially flat, and reference to their surface refers to the surface of one of the two larger faces. In some embodiments, there can also be other smaller sensors, but at least the pluralities of sensors discussed above have, in these embodiments, a surface area of more than 100 cm2each. The use of a plurality of sensors having relatively large dimensions may be preferred, particularly to prevent a very large number of sensors, while enabling at the same time the detection of the presence of the person in correspondence with a large part of the total surface of the mattress below which the device is mounted. In this way, wiring in the device can be minimized, particularly the wiring in the flexible support, and / or the wiring that connects the sensors to an electronic management and / or communication unit.

[0027] When reference is made herein to the surface of the pressure sensors, it refers to the surface effective for detecting pressure, i.e. , the surface of the pressure sensor which is pressure-sensitive such that when pressure is exerted on said surface, it affects the output signal of the sensor.

[0028] In some embodiments of the invention, each pressure sensor, viewed in a plan view, has a substantially rectangular or square shape. It has been proven that, in this way, for example, a distribution of the sensors, for example, in rows and columns, can be readily established such that it allows the sensors to be distributed on the relevant part of the bed base such that it allows, for example, an efficient detection of the posture of a person.

[0029] In some embodiments of the invention, each pressure sensor of the pluralities of pressure sensors has an extension in the length direction of the flexible support of at least 15 cm, for example, at least 20 cm, and an extension in the width direction (y) of the flexible support (1) of at least 15 cm, for example, at least 20 cm. It has been proven that the use of relatively large sensors of this type allows detecting posture while at the same time preventing excessive wiring.

[0030] In some embodiments of the invention, the pressure sensors are arranged on the flexible support in a pattern, said pattern comprising at least three columns of pressure sensors extending in a longitudinal direction (x) on the flexible support, and at least three rows of pressure sensors extending perpendicular to the columns. In alternative embodiments, the sensor array may be oriented in a different direction. The columns may be oriented in a direction other than the longitudinal direction (x) on the flexible support. In another alternative embodiment, the rows of sensors may be oriented in a direction not perpendicular to the direction defined by the columns- In another alternative embodiment, the sensors are arranged in a compact hexagonal pattern arrangement. Different geometric arrangements of the sensors can be made, substantially covering the area defined by the flexible support, also including irregular patterns.

[0031] In some embodiments of the invention, the pattern consists of 3 columns and 4 rows of pressure sensors. It has been proven that by using large pressure sensors, for example, with layout dimensions of 15 cm or more x 20 cm or more, a 3X4 array may be optimal, a compromise between a reduced number of pressure sensors and sufficient capacity to deduce the position of the person.

[0032] In some embodiments of the invention, the device comprises an electronic unit, each pressure sensor being connected to the electronic unit by a cable and the electronic unit being configured to process signals from the pressure sensors. The electronic unit can manage the reception of signals indicative of pressure from the sensors, for example, it can convert analog signals into digital format and manage the communication of pressure-related data to an external unit.

[0033] In some of these embodiments of the invention, the electronic unit further comprises a wireless transmitter configured to transmit pressure data obtained from the signals of the pressure sensors to an external unit. In some embodiments of the invention, the electronic unit is provided with fixing means for removably fixing the electronic unit to a bed. These means may comprise or consist of, for example, at least one magnet or at least one Velcro strap.

[0034] In some embodiments of the invention, the device comprises a multiplexer (for example, mounted in the flexible support), each pressure sensor being connected by a cable to an input of the multiplexer and the electronic unit being connected to an output of the multiplexer. The electronic unit is connected to the output port of the multiplexer and receives signals from each pressure sensor. The multiplexer allows simplifying the wiring of the device. Each pressure sensor adds a cable to the system to enable sending the measured pressure, scaling the number of cables the larger the number of pressure sensors is in the device. A multiplexer allows reducing the number of output cables of the system. The multiplexer comprises input port to which each pressure sensor is connected; for example, the multiplexer may have as many input ports as the number of pressure sensors in the device. The multiplexer can allow transmitting the measurement of each pressure sensor from the flexible support with a single output cable of the multiplexer, connected to the electronic unit. Furthermore, the multiplexer may be associated with cables or wires that allow controlling and powering the multiplexer itself.

[0035] In some embodiments of the invention, the flexible support has a length of between 120 and 200 cm. It has been proven that this may be suitable for obtaining values relating to a sufficient surface of a bed to enable, for example, estimating a risk of falling. In this document, intervals defined in terms such as “between A and B” include A and B, i.e. , the indicated end values. The indicated length is that which corresponds with an unfolded, but non-elastically stretched state of the flexible support.

[0036] In some embodiments of the invention, the flexible support has a width of between 60 and 130 cm. It has been proven that this may be suitable for obtaining values relating to a sufficient surface of a bed to enable, for example, estimating a risk of falling.

[0037] In some embodiments of the invention, the device is configured such that the flexible support can be folded according to a plurality of folding lines, such that all the pressure sensors are superimposed with respect to one another, forming a single column of pressure sensors. In this way, the device can be folded until it has a very small size, which facilitates storage, transport, and handling. The size of the folded device may be not much larger than the size of the largest pressure sensors.

[0038] In some embodiments of the invention, the device, in a folded state, has a substantially square or rectangular shape, with each side having a length of between 20 and 40 cm. Therefore, despite the pressure sensors being able to have a considerable size, the device can adopt a folded state with a small size, facilitating storage and handling.

[0039] In some embodiments of the invention, the flexible support comprises a plurality of fixing means for fixing the flexible support to a bed base. Examples of fixing means can be, for example, elastic (or non-elastic) bands attached to the flexible support which are coupled to or surround a part of the bed base on which the flexible support is placed. Another example of fixing means can be Velcro fixing elements.

[0040] In some embodiments of the invention, the device is part of a system for detecting the posture of a person on a bed, comprising: the device, a reclinable bed base with a reclining shaft, and a mattress placed on the bed base.

[0041] The flexible support is located below the mattress and on the bed base, with the third part of the flexible support being located above the reclining shaft of the bed base, such that the third part can deform elastically when the bed is reclined, whereby the risk of the pressure sensors changing position with respect to the bed base when the bed base goes from an extended state to a reclined state, and vice versa, can be reduced. The thickness of the device is preferably smaller than the thickness of the mattress, such that a person on the bed will not be able to perceive the difference in height between the areas of the mattress on the device such as, for example, the central area of the mattress, and the areas of the mattress directly on the bed base (if any) such as, for example, the outer areas of the mattress closer to the edge of the bed.

[0042] The described device can be used in many methods relating to the detection of the postures of people on a bed. For example, the device can be used in a method for reducing the risk of a person on a bed falling off same, the method comprising: detecting, with a device as described above, pressure data relating to a position of a person on a bed; transmitting the pressure data to an external unit, determining, preferably in the external unit, a risk of falling off the bed based on the pressure data; and emitting an alarm signal if the risk exceeds a predefined threshold.

[0043] BRIEF DESCRIPTION OF THE DRAWINGS

[0044] As a complement to the description, and for the purpose of helping to make the features of the invention more readily understandable, in accordance with practical exemplary embodiments of the invention, said description is accompanied by a set of figures which, by way of illustration and not limitation, represent the following:

[0045] Figure 1 shows a schematic plan view of a device for detecting and monitoring the posture of a person on a bed according to an embodiment of the invention.

[0046] Figures 2A and 2B show schematic longitudinal section views of the device according to this embodiment, positioned on the bed base of a reclinable bed, in a non-reclined position and a reclined position, respectively.

[0047] Figures 3-6 show schematic plan views of the device, according to other embodiments of the invention.

[0048] Figure 7 schematically shows the different parts making up the device, according to an embodiment of the invention.

[0049] Figures 8A-8C show longitudinal section views of the device, according to three different embodiments thereof.

[0050] Figure 9 schematically shows the configuration of a multiplexer which is part of the device, in some embodiments of the invention.

[0051] Figure 10 schematically shows an arrangement of the pressure sensors once the flexible support is folded, according to a possible embodiment of the invention.

[0052] Figure 11 shows a longitudinal section view of the device, placed on the bed base of a reclinable bed in a non-reclined position and below a mattress, according to an embodiment of the invention.

[0053] Figure 12 shows the steps of a method in which the device of the invention is used for detecting the posture of a person and emitting an alarm depending on the posture and the associated risk of falling.

[0054] DESCRIPTION OF EMBODIMENTS OF THE INVENTION Figure 1 shows a first embodiment of a device 100 according to the invention. A flexible support 1 has a length L and a width A, with the length L preferably being greater than the width A. Typically, the length L and the width A can be the same as or smaller than the length and the width of a bed base of a bed, on which the flexible support 1 is placed. The flexible support 1 may have a length L and width A configuration such that the flexible support 1 may have a rectangular or square, or approximately rectangular or square, configuration.

[0055] The flexible support 1 comprises two ends, a first end 101 closer to the headboard of the bed and a second end 102 opposite the headboard of the bed.

[0056] In this embodiment, twelve pressure sensors 2 arranged in an array, i.e., in three columns and four rows, are arranged in the flexible support 1.

[0057] The functionality of the flexible support 1 is, among others, to favor the folding thereof according to folding lines 16, allowing the shape thereof to be modified to a folded and compact configuration. The folding lines 16 are arranged in areas of the flexible support 1 that are free of pressure sensors 2 to prevent twisting the pressure sensors 2 that are typically more fragile to twisting than the flexible support 1. The folding lines 16 may be marked on the flexible support 1 , for example, by means of the arrangement of notches on the flexible support 1 that guide the folding. Furthermore, or alternatively, in embodiments of the invention, the folding lines 16 may be visually marked on the flexible support 1. In other embodiments, the folding lines 16 are neither physically nor visually marked on the flexible support 1.

[0058] The flexible support 1 comprises a first part 11 in which one of the rows of pressure sensors 2 is arranged, a second part 12 in which three of the rows of pressure sensors 2 are arranged, and a third elastic part 13.

[0059] The third elastic part 13 is located between the first part 11 and the second part 12 and is formed by an elastic material.

[0060] Each pressure sensor 2 is connected by a cable 17 to an electronic unit 15 through a multiplexer 14. The cables 17 connecting pressure sensors 2 that are close to one another can be arranged grouped on the flexible support 1 in an organized manner and aligned with respect to one another, from the pressure sensors 2 to the multiplexer 14. The electronic unit 15 is configured to receive and process pressure data or signals generated by the pressure sensors 2.

[0061] Furthermore, the electronic unit 15 comprises a wireless transmitter 15A and fixing means 15B. The multiplexer 14 is responsible for reducing the number of cables 17 coming out of the flexible support 1, necessary for transmitting the pressure data generated by the pressure sensors 2 to the electronic unit 15, from twelve cables 17 to, for example, one output cable 20, or to a reduced number of cables. The pressure data is sent by the electronic unit 15 through the wireless transmitter 15A to an external unit 2000 responsible for processing and interpreting the pressure data. The fixing means 15B allow fixing the electronic unit to a bed structure, for example, to a bed base. For example, the fixing means 15B may comprise strips or straps, for example, Velcro straps, that serve to fasten the electronic unit to a part of a bed structure or bed base or, for example, magnets fixed to the electronic unit 15 which allow the electronic unit 15 to be fixed to the bed base.

[0062] Figure 2A shows a longitudinal section view of the device 100 according to this embodiment of the invention, positioned on a reclinable bed base 1000, in a straight or non-reclined position of the bed base 1000. The bed base 1000 comprises a reclinable part 1001 associated with the headboard part of the bed, that can be reclined with respect to the contiguous part 1002 of the bed base 1000. Reclination is performed with respect to a reclining shaft 1003 located between the reclinable part 1001 and the contiguous part 1002 of the bed base 1000. Reclination of the bed base 1000 has the functionality of, for example, making it easier for the person to get out of the bed in order to eat or read.

[0063] The first part 11, of length L1 , of the flexible support 1 is arranged on the reclinable part 1001 of the bed base 1000. The second part 12, of length L2, of the flexible support 1 is arranged on the contiguous part 1002 of the bed base 1000. A part of the third elastic part 13, of initial length L3, is arranged above the reclining shaft 1003 of the bed base 1000. The total length of the three parts is L in a non-reclined position of the bed base 1000.

[0064] The first part 11 is located on the reclinable part 1001 of the bed base 1000, where the area of the head, shoulders, chest, or upper part of a person is typically supported. The second part 12 is located on the contiguous part 1002 of the bed base 1000, where the lower part (including, for example, the legs) of a person is typically supported, for example.

[0065] At least a part of the third elastic part 13 is located above the part of the reclining shaft 1003 of the bed base 1000. The reclinable bed base 1000 allows at least reclining the headboard part, or the reclinable part 1001 accommodating the head, the shoulders, or the upper part of a person who is lying down, with respect to the contiguous part 1002 of the bed base 1000.

[0066] The flexible support 1 is fixed to the bed base 1000 by fixing means 18, which can be, for example, elastic (or non-elastic) bands attached to the flexible support 1 which are coupled to or surround a part of the bed base 1000 on which the flexible support 1 is placed. Other fixing means 18 can be, for example, Velcro straps and / or patches.

[0067] In Figure 2B the bed base 1000 is in the reclined position. In the reclined configuration of the bed base 1000, the length L1 of the first part 11 and the length L2 of the second part 12 remain constant, while the initial length L3 of the third elastic part 13 increases to a reclined length L3’ with respect to the non-reclined position of the bed base 1000. The total length of the device 100 is L’ in the reclined configuration of the bed base 1000, with L’>L.

[0068] The functionality of the third elastic part 13 is to keep the first part 11 and the second part 12 of the flexible support 1 attached to one another and in the same position when reclining the bed base 1000. Typically, reclinable beds used in hospitals (or for other uses) comprise a mechanism that allows reclining the bed base 1000 such that they induce a rotation in the middle part of the body of a person on the bed, for greater comfort. This mechanism allows an eccentric reclination to be performed with respect to the reclining shaft 1003, typically involving a longitudinal movement of the reclinable part 1001 of the bed base 1000 in synchronization with the change in angle exerted by the reclining shaft 1003. This longitudinal movement causes an effective separation between the first part 11 and the second part 12 of the flexible support 1, causing the lengthening of the third elastic part 13 of the flexible support 1 (typically, of 5 cm or more), which allows reducing the risk of the sensors 2 moving in relation to the bed base 1000 as a result of pivoting. This allows measuring more reliable pressure data, since the pressure sensors 2 are kept in place with respect to the person on the device 100. The third flexible part 13 can also serve to reduce the risk of damage, for example, tears, in the flexible support as a result of reclining the bed base 1000.

[0069] Figure 3 shows a plan view of the device 100 according to another embodiment of the invention, similar to the embodiment of Figure 1 but in which the third elastic part 13 comprises two elastic bands (each with a width A1 smaller than the half the width A of the first part 11 and than width A of the second part 12) attaching the first part 11 and the second part 12 of the flexible support 1 , instead of a single wide band such as the one of Figure 1.

[0070] The cables 17 of the pressure sensors 2 are grouped based on the arrangement of the two elastic bands, allowing connection through the third elastic part 13.

[0071] Figure 4 shows a plan view of the device 100 according to another embodiment of the invention, similar to the embodiment of Figure 1 but in which the entire flexible support 1 is elastic. In this case, mention can be made to a third elastic part 13, i.e. , the part which is located between the first part 11 , having three pressure sensors 2, and the second part 12, having nine pressure sensors 2. However, in this embodiment, the third elastic part 13 is not distinguished from the first part 11 and the second part 12 in terms of its constitution, i.e., in terms of the materials making up same.

[0072] In this embodiment, the pressure sensors 2 have been illustrated as circles to reflect the fact that the pressure sensors 2 are not necessarily rectangular, such as in Figure 1. The pressure sensors 2 may have any shape that is suitable for their function.

[0073] Figure 5 shows a plan view of the device 100 according to another embodiment of the invention, in which the second part comprises a first sub-part 12A and a second sub-part 12B separated by a fourth part 19, the fourth part 19 being elastic. In this embodiment, the fourth part 19 is preferably located above a second reclining shaft of the reclinable bed base 1000, for example, in correspondence with the knees of a person who is lying down on the bed.

[0074] In alternative embodiments, there may be a plurality of elastic parts, equal to or larger than the number of reclining shafts of the reclinable bed base 1000. Each elastic part may comprise one or more narrow bands, as explained in reference to Figure 3.

[0075] Figure 6 shows a plan view of the device 100 according to another embodiment of the invention, similar to the embodiment of Figure 1, in which the flexible support 1 comprises an alternative pattern of pressure sensors 2, in this case, with some of them arranged in zig-zag.

[0076] Figure 7 schematically shows the different parts making up the device 100 according to the invention, represented by the larger rectangle. The device 100 comprises the flexible support 1, which includes pressure sensors 2 connected by cables 17 to a multiplexer 14. The device 100 further comprises an electronic unit 15 which in turn comprises a wireless transmitter 15A connected to the electronic unit 15 and fixing means 15B, which are depicted inside a rectangle separated from the flexible support 1 as they are physically separated from the flexible support 1 and connected with the multiplexer 14 through an output cable 20.

[0077] Figure 8A shows a longitudinal section view of the device 100 according to an embodiment of the invention, in which the pressure sensors 2 are located between an upper layer 103 and a lower layer 104, forming the flexible support 1. The total thickness of the device 100 is E and the thickness of the pressure sensors 2 is E2.

[0078] Figure 8B shows a longitudinal section view of the device 100 according to an embodiment of the invention, in which the pressure sensors 2 are located on an upper face 105 of the flexible support 1, the flexible support 1 also having a lower face 106. The total thickness of the device 100 is E and the thickness of the pressure sensors 2 is E2.

[0079] Figure 8C shows a longitudinal section view of the device 100 according to an embodiment of the invention, in which the pressure sensors 2 are located inside the flexible support 1, i.e. , embedded in the flexible support 1 between its upper face 105 and lower face 106. The total thickness of the device 100 is E and the thickness of the pressure sensors 2 is E2.

[0080] In Figures 8A, 8B, and 8C, the thickness E of the flexible support 1, the thickness of the third elastic part 13, and the thickness E2 of the pressure sensors 2 are exaggerated for ease of viewing. Preferably, the thicknesses E and E2 are considerably smaller than the length L of the flexible support 1 , for example, less than 0.5 cm. For example, E may preferably be less than 2 mm, to facilitate folding. The weight of the assembly is preferably less than 500 grams, for example, less than 300 grams, which facilitates transport by people.

[0081] In one embodiment, the pressure sensors 2 are substantially flat and comprise a surface area of at least 100 cm2. In this way, the number of sensors comprised in the device 100 is minimized, minimizing the number of cables 17, thereby facilitating the maintenance of the device 100, its control, and folding.

[0082] In one embodiment, by using large pressure sensors 2, for example, with layout dimensions of 15 cm or more x 20 cm or more, a 3X4 array may be optimal, a compromise between a reduced number of pressure sensors 2 and sufficient capacity to deduce the position of the person.

[0083] Figure 9 schematically shows a multiplexer 14 which is part of the device 100 in an embodiment of the invention, in which the cables 17 connect the pressure sensors 2 with the multiplexer 14, an output cable 20, which in turn comprises a reduced number of conducting wires that allow powering and controlling the multiplexer 14 and the output of the multiplexed signal which transmits the information provided by the pressure sensors 2 to the electronic unit 15.

[0084] The multiplexer 14 allows the wiring of the device 100, particularly, the output wiring of the flexible support 1, to be simplified. Each pressure sensor 2 adds a cable 17 in the system to enable sending the measured pressure, scaling the number of cables 17 the larger the number of pressure sensors 2 is in the device 100. The multiplexer 14 allows reducing the number of output cables of the flexible support 1 to one output cable 20 with a reduced number of conducting wires, for example, with four conducting wires, for example, two for signals / data and two for power.

[0085] Figure 10 schematically shows an arrangement of the pressure sensors 2 once the flexible support 1 is folded along the folding lines 16. The arrangement of the folding lines 16, the arrangement of the cables 17 which are organized and aligned with respect to one another on the flexible support 1, and the relatively small number of pressure sensors 2 allow folding the device 100 in a compact configuration without damaging the different parts. For the sake of clarity, neither the flexible support 1 nor the third elastic part 13 is illustrated. In some embodiments, the folding lines 16 are not predefined on the flexible support 1, and folding can be performed on any line of the flexible support 1 in which pressure sensors 2 are not present.

[0086] Figure 11 shows in a longitudinal section a bed 4000 which incorporates the device 100 for detecting and monitoring the posture of a person, according to an embodiment of the invention, the device 100 being located on the reclinable bed base 1000 in a non-reclined position and below a mattress 3000. The thickness of the device 100 is much smaller than the thickness of the mattress 3000, such that a person on the bed 4000 will not be able perceive the difference in height between the areas of the mattress 3000 on the device 100 such as, for example, the central area of the mattress 3000, and the areas of the mattress 3000 directly on the bed base 1000 (if any) such as, for example, the outer areas of the mattress 3000 closer to the border of the bed 4000. In some embodiments, the flexible support 1 may not have fixing means 18, remaining fixed in the same position on the bed base 1000 as a result, for example, of the friction generated by the weight of the mattress 3000 on the bed base 1000.

[0087] This invention can be used in, for example, a method such as the one schematically illustrated in Figure 12. This method comprises a first step 4001 of detecting, with a device 100 as described above, pressure data relating to a position of a person on a bed 4000, a second step 4002 of transmitting the pressure data to an external unit 2000, a third step 4003 of determining, preferably in the external unit 2000, a risk of falling off the bed based on the pressure data, and a fourth step 4004 of emitting an alarm signal if the danger of falling exceeds a predefined threshold.

[0088] The predefined threshold can be calculated by means of processing the pressure data generated by the pressure sensors 2. The predefined threshold can be defined as a specific criterion which, when met, indicates a high risk of a person on the bed 4000 falling off. Said specific criterion may depend, for example, on the detected instantaneous position of the person on the bed 4000, the evolution of the position of the person on the bed 4000 over time, or movement patterns of a person on the bed 4000. The emitted alarm signal can be directed to the personnel in charge of the person on the bed 4000, where the signal can be a sound and / or light signal.

Claims

CLAIMS1. A device (100) for detecting a posture of a person on a bed, the device (100) comprising: a flexible support (1) having a length (L) and a width (A), the flexible support (1) having a first end (101) and a second end (102), with the length (L) being the distance between the first end (101) and the second end (102); the flexible support (1) comprising: a first part (11) in which a plurality of pressure sensors (2) are arranged; and a second part (12) in which a plurality of pressure sensors (2) are arranged; the first part (11) being closer to the first end (101) than the second part (12), and the second part (12) being closer to the second end (102) than the first part (11); characterized in that the flexible support (1) also comprises a third part (13), located between the first part (11) and the second part (12), said third part (13) being elastic, such that it can deform elastically, allowing an increase in the distance between the first part (11) and the second part (12).

2. The device (100) according to claim 1, wherein the third part (13) is configured to be able to stretch elastically at least 5 cm parallel to a longitudinal axis of the flexible support (1).

3. The device (100) according to any of the preceding claims, wherein the width (A) of the flexible support (1) is constant along the flexible support (1), between the first end (101) and the second end (102).

4. The device (100) according to claim 1 or 2, wherein the third part (13) consists of at least one attachment band between the first part (11) and the second part (12), with a width (A1) smaller than the width (A) of the first part (11) and than the width (A) of the second part (12).

5. The device (100) according to any of the preceding claims, wherein the third part (13) has an extension of at least 10 cm in a longitudinal direction.

6. The device (100) according to any of the preceding claims, wherein the second part (12) comprises a first sub-part (12A) and a second sub-part (12B) separated by a fourth part (19), the fourth part (19) being elastic.

7. The device (100) according to any of the preceding claims, wherein the first part (11) and the second part (12) are made of a first material and wherein the third part (13) is made of a second material, different from the first material.

8. The device (100) according to any of the preceding claims, wherein at least the first part (11) and the second part (12) each comprises at least one upper layer (103) and a lower layer (104) between which the respective pressure sensors (2) are located.

9. The device (100) according to any of the preceding claims, wherein each pressure sensor (2) has a surface area of at least 100 cm2.

10. The device (100) according to any of the preceding claims, wherein each pressure sensor (2), viewed in a plan view, has a substantially rectangular or square shape.

11. The device (100) according to any of the preceding claims, wherein each pressure sensor (2) of the pluralities of pressure sensors (2) has an extension in the length direction (x) of the flexible support (1) of at least 15 cm and an extension in the width direction (y) of the flexible support (1) of at least 15 cm.

12. The device (100) according to claim 11, wherein each pressure sensor (2) of the pluralities of pressure sensors (2) has an extension in the length direction (x) of the flexible support (1) of at least 20 cm and an extension in the width direction (y) of the flexible support (1) of at least 20 cm.

13. The device (100) according to any of the preceding claims, wherein the pressure sensors (2) are arranged on the flexible support (1) in a pattern, said pattern comprising at least three columns of pressure sensors (2) extending in a longitudinal direction (x) on the flexible support (1), and at least three rows of pressure sensors (2) extending perpendicular to the columns.

14. The device (100) according to claim 13, wherein the pattern consists of 3 columns and 4 rows of pressure sensors (2).

15. The device (100) according to any of the preceding claims, wherein the device comprises an electronic unit (15), each pressure sensor (2) being connected to the electronic unit by a cable (17) and the electronic unit being configured to process signals from the pressure sensors (2).

16. The device (100) according to claim 15, wherein the electronic unit (15) further comprises a wireless transmitter (15A) configured to transmit pressure data obtained from the signals from the pressure sensors (2) to an external unit (2000).

17. The device (100) according to claim 16, wherein the electronic unit (15) is provided with fixing means (15B) for removably fixing the electronic unit to a bed.

18. The device (100) according to any of claims 15-17, wherein the device comprises a multiplexer (14), each pressure sensor (2) being attached with a cable (17) to an input of the multiplexer (14) and the electronic unit (15) being connected to an output of the multiplexer (14).

19. The device (100) according to any of the preceding claims, wherein the flexible support (1) has a length (L) of between 120 and 200 cm.

20. The device (100) according to any of the preceding claims, wherein the flexible support (1) has a width (L) of between 60 and 130 cm.

21. The device (100) according to any of the preceding claims, wherein the device (100) is configured such that the flexible support (1) can be folded according to a plurality of folding lines (16), such that all the pressure sensors (2) are superimposed with respect to one another, forming a single column of pressure sensors (2).

22. The device (100) according to claim 21 , wherein the device (100) has, in a folded state, a substantially square or rectangular shape, with each side having a length of between 20 and 40 cm.

23. The device (100) according to any of the preceding claims, wherein the flexible support (1) comprises a plurality of fixing means (18) for fixing the flexible support (1) to a bed base (1000).

24. A system for detecting the posture of a person on a bed, comprising: a device (100) according to any of the preceding claims, a reclinable bed base (1000) with a reclining shaft (1003), a mattress (3000) placed on the bed base (1000); characterized in that the flexible support (1) of the device (100) is located below the mattress (3000) and on the bed base (1000), with the third part (13) of the flexible support (1) of the device (100) being located above the reclining shaft (1003) of the bed base (1000), such that the third part (13) can deform elastically when the bed is reclined.

25. A method for reducing the risk a person on a bed falling off same, the method comprising: detecting, with a device (100) according to any of claims 1-23, pressure data relating to a position of a person on a bed; transmitting the pressure data to an external unit (2000), determining, preferably in the external unit (2000), a risk of falling off the bed based on the pressure data; and emitting an alarm signal if the risk exceeds a predefined threshold.

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