Support device and method for supporting a person

Abstract

The invention relates to a support device for supporting a person, said support device comprising in sequence : - a cover layer which provides a main support surface, - an auxiliary device comprising a group of inflatable support elements for supporting and influencing the shape of the main support surface, - a group of sensors, wherein one or more sensors of the group of sensors is associated with one inflatable support element of the group of inflatable support elements and is configured for sensing a force exerted on the respective inflatable support element by the person, and - a padding layer for providing cushioning. The support device further comprises a fluid control unit which is configured to selectively supply fluid under pressure to one or more inflatable support elements, and a programmable control unit for controlling the support device.

Description

[0001] Support device and method for supporting a person

[0002] BACKGROUND

[0003] The invention relates to a support device and a method for supporting persons . A person using the support device can be supported while sitting or recumbent .

[0004] A device and method for supporting persons is , for example , known from WO 2019 / 231317 from the same applicants . The known support device has a main support surface for the body of a person, comprising an auxiliary device for influencing the shape of the main support surface . The auxiliary device comprises :

[0005] - a group of support elements for supporting the main support surface , which group is positioned on the side of the main support surface that faces away from the bodysupporting side , wherein the support elements each comprise a sub-support surface,

[0006] - adj ustment means for each sub-support surface for influencing the height of each sub-support surface relative to a reference plane and consequently the local height of the main support surface ,

[0007] - monitoring means for each sub-support surface for monitoring the height of the respective sub-support surface and / or the force exerted on the respective sub-support surface by the person, and

[0008] - a programmable control unit for controlling the adj ustment means in response to data received from the monitoring means .

[0009] The support elements each comprise an elastically bendable plate that is connected to the adj ustment means so as to be influenced thereby in its extent of bending . The bending plate is connected to the sub-support surface in order to influence its height depending on the extent of bending imposed by the adj ustment means . The adj ustment means each comprise an electromotor that is situated on the concave side of the bending plate .

[0010] The known support device provides the possibility of adj usting either the shape of the main support surface, or the distribution of the forces exerted on it by the user, in response to the actual condition . The combination of adj ustment means and electromotor, which preferably is a stepper motor, for each sub-support surface, the monitoring means and the bending plates make it possible to influence, in particular adj ust the sub-support surfaces and consequently the main support surface, accurately .

[0011] SUMMARY OF THE INVENTION

[0012] A disadvantage of the previously mentioned known device for supporting persons is that the main support surface feels relatively hard, in particular when a person takes a seat on the main support surface , lies down on the main support surface , or leans against the main support surface , and the various support elements are not yet controlled to adj ust the shape of the main support surface or the distribution of the forces on the main support surface by the user .

[0013] It is an obj ect of the present invention to provide a support device that is more comfortable to the supported user, speci fically for a person sitting or lying on the main support surface , or leaning against the main support surface .

[0014] According to a first aspect , the present invention pertains to support device comprising : a cover layer which provides a main support surface for the body of a person, an auxiliary device for influencing the shape of the main support surface, comprising a group of inflatable support elements for supporting the main support surface , wherein the inflatable support elements are positioned on the side of the cover layer that faces away from a main support surface , wherein each inflatable support element of the group of support elements comprises a connector for supplying and / or removing fluid in / out the inflatable support element, wherein each support element comprises a sub-support surface adj acent to the cover layer, a group of sensors , wherein one or more sensors of the group of sensors is associated with one inflatable support element of the group of inflatable support elements and is configured for sensing a force exerted on the respective inflatable support element by the person, wherein the sensors are arranged at a side of the respective inflatable support element facing away from the cover layer, a padding layer for providing cushioning, wherein the padding layer is arranged at a side of the auxiliary device facing away from the cover layer, a fluid control unit which is arranged in fluid connection with the connectors of the inflatable support elements and is configured to selectively supply fluid under pressure to one or more inflatable support elements of the auxiliary device, and / or to selectively remove fluid from one or more inflatable support elements , and a programmable control unit connected to the fluid control unit for controlling the fluid supply to and / or the fluid removal from one or more inflatable support elements of the auxiliary device, wherein the sensors of the group of sensors are connected to the programmable control unit for providing signals to the programmable control unit that are indicative of the force exerted on the respective inflatable support elements .

[0015] The support device according to the invention provides a much more comfortable feel to a person sitting or lying on the main support surface , or leaning against the main support surface , due to the combination of the following three aspects :

[0016] 1 . The use of inflatable support elements , which can much more easily deform when a person takes place on main support surface of the support device of the invention, at least when compared to the elastic bendable plates as used in the prior art support device ,

[0017] 2 . Arranging the sensors at a side of the respective inflatable support element that faces away from the cover layer . Since for each sensor, the respective inflatable support element is arranged in between the sensor and the cover layer, the presence of a sensor is not felt by a person that takes place on the main support surface of the support device of the invention, and

[0018] 3 . The arrangement of a padding layer provides additional cushioning when a person takes place on main support surface of the support device of the invention .

[0019] It is noted that the arrangement of the inflatable support elements in between the padding layer and the cover layer, and adj acent to the cover layer, provides the possibility of accurately adj usting either the shape of the main support surface to a desired shape , or the distribution of forces exerted by a user to a desired force distribution .

[0020] It is further noted, that when using a sheet with sensors in between the cover layer and the inflatable support elements , the sheet is usually not stretchable and / or vapor- or moisture permeable , which may provide some discomfort , and is therefore not desired .

[0021] Furthermore , the padding layer may comprise any known material used in upholstery and / or mattresses for providing cushioning and support .

[0022] At least when compared to the auxi liary device as disclosed in the prior art document WO 2019 / 231317 , the auxiliary device of the present invention may also have one or more of the following advantages : The auxiliary device may provide a higher force , it may provide a faster response , the construction can be more simple , the device can be lighter in weight , and has lower material costs .

[0023] In an embodiment , each inflatable support element of the group of inflatable support elements is provided with its own associated one or more sensors of the group of sensors . Accordingly this embodiment allows to sense a force exerted by the person on each individual inflatable support element of the group of inflatable support elements .

[0024] In an embodiment, the one or more sensors of the group of sensors is arranged between its associated inflatable support element and the padding layer . The arrangement of the sensors adj acent to and under the inflatable support elements , as viewed from the cover layer, allows to obtain a measure substantially proportional to the force exerted on the inflatable support elements . When a person takes place on the cover layer, the padding layer will deform, resulting in a curved surface of the padding layer facing the inflatable support element . In this situation, at least some of the sensors will also be arranged on this curved surface , which may also influence the force measurement by these sensors , in that the measured force might deviate from the actual force . However, the inventors have found that the most important measure is not the actual force , but the relative force di f ferences between the sensors . During use of the device of the invention, this relative force as can be established from the signals that are indicative of the force exerted on the respective support elements , is preferably used in the programmable control unit in order to control the device of the invention .

[0025] In an embodiment , the one or more sensors are at least partially sunken or recessed into the padding layer . This further can assure that the sensors are not felt by a person that takes place on the support device of the present invention .

[0026] In an embodiment , the one or more sensors associated with an inflatable support element are connected to said inflatable support element . In an embodiment , the one or more sensors are fixedly connected to said inflatable support element . For example , the one or more sensors may be fixedly connected to said inflatable support element via a glue connection . Accordingly, the position of the one or more sensors associated with an inflatable support element is substantially fixed with respect to said inflatable support element . This may prevent an inadvertent movement between the one or more sensors and the associated inflatable support element .

[0027] In an embodiment , the one or more sensors are concentrically connected to a side of the inflatable support element that facing away from the cover layer . In an embodiment, a center line of the inflatable support element passes through a center of the one or more sensors .

[0028] In an embodiment, each sensor comprises a base plate at a side of the sensor facing away from the associated inflatable support element, preferably wherein the base plate is a substantially rigid base plate . A base plate is particularly advantageous when the sensor is arranged on the surface of the padding layer that is facing the inflatable support elements , in which case the substantially rigid base plate provides a solid support surface for the sensor .

[0029] In an embodiment, the base plate is provided with a rounded edge at least at a side where data leads connect to the sensor . The rounded edge substantially prevents that the data leads may get damaged on the edge of the base plate, in particularly when the sensors and their base plate move along with the surface of the padding layer when a person takes place on the device of the present invention .

[0030] In an embodiment , each sensor comprises a top plate at a side of the sensor facing towards the associated inflatable support element, preferably wherein the top plate is a substantially rigid top plate . The top plate provides a more stable passing of the force on the inflatable support element on the sensor . In particular in case when the inflatable support element comprises a flexible material at least at the side facing the sensor, the substantially rigid top plate allows to more ef ficiently pass the force on the inflatable support element on to the sensor .

[0031] In an embodiment, each sensor of said group of sensors is a thin film sensor, preferably wherein said thin film sensor comprises a piezoelectric material or a pressure sensitive ink . A thin film sensor can limit the total height of the device of the present invention . In case the thin film sensor is too fragile to be used in between the inflatable support element and the padding layer, the thin film sensor is preferably sandwiched between a base plate and a top plate as described above .

[0032] In an embodiment, the padding layer comprises a foam layer, preferably a layer of resilient foam material , more preferably a layer of resilient polymer foam material , like cellular Polyurethane foam, memory foam or latex foam, and / or any other material used in upholstery and / or mattresses for providing cushioning and support .

[0033] In an embodiment, one or more of the inflatable support elements of the group of inflatable support elements is surrounded by a padding layer part, at least in a plane substantially parallel to the cover layer . Preferably, the inflatable support elements are at least partially imbedded in the padding layer . In an embodiment, the padding layer parts extend towards and contact the cover layer . Accordingly, the padding layer part ( s ) that surround the inflatable support element ( s ) and reaches up to the cover layer, may provide an enclosure for the inflatable support element ( s ) , which may assist in stabilizing the position and / or orientation of the inflatable support element ( s ) .

[0034] In an embodiment , the fluid control unit comprises a pump and a manifold, wherein the pump is connected to the mani fold and configured to supply fluid under pressure to the mani fold, and wherein the manifold is connected to the connectors of the inflatable elements and configured to selectively supply fluid under pressure to one or more inflatable elements of the auxiliary device, and / or to selectively remove fluid from one or more inflatable elements .

[0035] In an embodiment , the mani fold comprises a series of valves , wherein each valve of said series of valves is configured for selectively providing a fluid connection between the pump and one of the inflatable support elements and / or between the environment and said one of the inflatable support elements , wherein the programmable control unit is connected to the mani fold and is configured to generated operational commands to the series of valves to achieve a desired pressure in each of the inflatable support elements of the auxiliary device .

[0036] In an embodiment , the support device comprises a pressure sensor which is arranged in fluid communication with a fluid supply device and / or one or more of the inflatable support elements . In an embodiment , the pressure sensor is arranged in fluid communication with one or more of the inflatable support elements via a valve . In an embodiment , the support device comprises a group of pressure sensors , wherein each pressure sensor of said group of pressure sensors is in fluid communication with at least one inflatable support element , wherein the pressure sensors of the group of pressure sensors are connected to the programmable control unit for providing signals that are indicative of the fluid pressure inside the respective inflatable support elements . Accordingly, in addition to the group of sensors that are configured to measure the force on the inflatable support elements of the device of the invention, this embodiment also comprises one or more pressure sensors , preferably a group of pressure sensors , to establish the fluid pressure inside one or more of the inflatable support elements , preferably to provide additional data to the programmable control unit that can be used for controlling the inflation and / or deflation of the one or more inflatable support elements of the device of the invention .

[0037] It is noted that the pressure sensor or the pressure sensors of the group of pressure sensors may be used for calibrating the sensors of the group of sensors that are arranged at a side of the respective inflatable support element facing away from the cover layer, for example to correct for product variations in the sensors of the group of sensors , for a non-symmetric arrangement of the sensor of the group of sensors with respect of the associated inflatable support element , or for correcting an oblique or skewed orientation of the sensor of the group of sensors at a position where an inflatable support element is not symmetrically loaded when a person takes place on the support device .

[0038] In an embodiment , the programmable control unit is configured to distinguish between obj ects on the device of the present invention, based on the data from the group of sensors and / or the group of pressure sensors . Preferably, the programmable control unit can distinguish between an obj ect, for example a bag ( for example by detecting the absence of movement and / or a very limited cumulated load) , a child ( for example by detecting movement and a relatively low weight , but preferably more than a bag) , and an adult ( for example by detecting movement and a relatively heigh weight ) .

[0039] In an embodiment , each one of the inflatable support elements comprises a bellows , preferably a bellows made from a flexible material . The use of a flexible material , preferably a flexible polymer material , also contributes to a more soft and thereby a more comfortable feel to a person sitting or lying on the main support surface , or leaning against the main support surface .

[0040] In an embodiment , one or more of the inflatable support elements comprises two or more bellows arranged one behind the other in a direction from the cover layer to the padding layer . Accordingly, said one or more of the inflatable support elements comprises a stack of said two or more bellows , which allows to increases the total available amplitude of said one or more of the inflatable support elements for influencing the shape of the main support surface, while keeping the surface area per support element substantially the same .

[0041] It is noted that the amplitude refers to the height of the inflatable support elements , and the total available amplitude is the maximum height the inflatable support elements can reach when substantially fully inflated .

[0042] In an embodiment , the two or more bellows that are arranged one behind the other in the direction from the cover layer to the padding layer are configured such that their internal volume are in fluid connection with each other . Accordingly, only one fluid supply tube is necessary for inflating and / or deflating these two or more stacked bellows .

[0043] In an alternative embodiment , two bellows of said two or more bellows are each provided with its own fluid supply line and its own control valves for selectively supplying and / or removing fluid from each one of the two bellows , preferably wherein one of the two bellows is configured for adapting a contour of the main support surface, and an other one of the two bellows is configured for providing a haptic feedback and / or a tissue stimulation .

[0044] In an embodiment , the support device comprises one or more support assemblies , each support assembly comprising three or more inflatable support elements which are arranged in a plane substantially parallel to the cover layer, and around a center point , preferably wherein one or more of said assemblies comprises four inflatable support elements around the center point . The three or more inflatable support elements of a support assembly can be configured to work at least partially together to adj ust not only a height of the main support surface at the center point, but also an inclination of the main support surface at the center point in a certain direction .

[0045] It is noted that such an inclination of the main support surface can also be obtained by providing a dif ference in height between two ad acent inflatable support elements . However, the support assemblies can provide more complex cooperation between the inflatable support elements of a support assembly, in particular by controlling the inflatable support elements of a support assembly as a group .

[0046] This also can provide a more easy way to control the auxiliary device , for example by controlling dif ferent support assemblies by means of the same or similar subroutines in the programmable control unit . For example, by providing a short term push by increasing and subsequent decreasing the height of the inflatable support members of a support assembly, which short term push is sequentially initiated at the adj acent inflatable support members in a clockwise or counter clockwise direction around the center point, a massaging action can be provided by the support assembly . By controlling two or more support assemblies with the same or similar subroutines , this massaging action can be performed at various locations of the auxiliary device .

[0047] In an embodiment , the inflatable support elements and the fluid control unit are configured to use a gas as the fluid, preferably air . As a gas , such as air, is a compressible fluid, when compared to a liquid as the fluid, it may also contribute to a more soft and thereby a more comfortable feel to a person sitting or lying on the main support surface , or leaning against the main support surface .

[0048] According to a second aspect , the present invention provides a seat provided with a support device or an embodiment thereof as described above . The arrangement of the device of the present invention in a seat allows to adj ust the pressure distribution under the person sitting on the seat to a suitable pressure distribution for said person, and / or to a personal contour of the person sitting on the seat , by controlling the various inflatable support elements and / or support assemblies , preferably based on the signals provided by the sensors .

[0049] The arrangement of the support device of the present invention in seat is particularly advantageous in any seat that is used during longer term use . Examples of such applications include a car seat, a seat in aviation for pilots and passengers , a motorbike seat or motorcycle saddle, a seat for train drivers and passengers , a seat for crew or passengers of a vessel , a control room seat, an office seat, a wheelchair, etc...

[0050] In an embodiment , the programmable control unit is configured for controlling the various inflatable support elements based on a signal from a transducer, preferably acceleration sensor or acceleration transducer, configured for sensing motions of a vehicle, vessel or airplane that comprises a seat with a support device according to the invention . In an embodiment, the transducer is part of the programmable control unit . Alternatively, the transducer may be part of an engine of the vehicle, vessel or airplane, and configured to send a signal to the programmable control unit . In an embodiment, the signal from the transducer comprises information about accelerations and / or vibrations of the vehicle , vessel or airplane, and wherein the programmable control unit is configured for at least partially damping and / or compensating these accelerations and / or vibrations .

[0051] In addition, the programmable control unit is preferably configured to control the various inflatable support elements and / or the support assemblies in order to provide a tissue stimulation of the tissue that is in contact with the seat in order to enhance the blood flow in said tissue .

[0052] Furthermore, the support device of the present invention in a seat allows to correct the posture of the person sitting on the seat , for example by initiating a pelvic tilt and / or a lower back rotation by initiating a change in the shape of the support surface by controlling the various inflatable support elements and / or support assemblies .

[0053] In an embodiment , the programmable control unit is configured to control the one or more inflatable support elements or the one or more support assemblies to combine two or more of the adj ustment of the pressure distribution, the tissue stimulation, and a beneficial slight change in posture and the posture correction . The control can be configured to provide a combination in time and / or in amplitude :

[0054] A combination in time provides a control to provide two or more of the adj ustment of the pressure distribution, the tissue stimulation, and the posture correction, at the same time or sequentially one after the other .

[0055] A combination in amplitude provides a control to provide two or more of the adj ustment of the pressure distribution, the tissue stimulation, and the posture correction, using di fferent parts of the available amplitude of the inflatable support elements . For example one part of the total available amplitude is reserved or used for the adj ustment of the pressure distribution, whereas another part of the total available amplitude is reserved or used for the tissue stimulation .

[0056] In an embodiment , the support device comprises two assemblies of two-by-two inflatable support elements which are arranged in a plane substantially parallel to the cover layer, wherein the two assemblies are arranged next to each other in a direction substantially parallel to a seat back, preferably wherein the center point of each assembly is positioned for supporting one of the sitting bones ( ischial tuberosity) of an average person . Preferably, the distance between the center points of the two assemblies is in a range from 100 to 150 mm, more preferably in a range from 110 to 140 mm.

[0057] In an embodiment , the support device is configured for initiating a pelvic tilt of a person supported by the support device . This pelvic tilt may be in a direction to the front and / or back of the person supported by the support device, and / or may be in a direction to the left and / or right of the person supported by the support device . Accordingly, the support device according to this embodiment allows to provide or initiate a lower back ( lumbar) movement of the person supported by the support device, which movement may provide a lower back stimulation .

[0058] In an embodiment, the seat comprises a seat back and / or a headrest, wherein the seat back and / or the headrest is / are provided with a support device or an embodiment thereof as described above .

[0059] According to a third aspect , the present invention provides a pillow, a seat cushion or a mattress provided with a support device or an embodiment thereof as described above . This can provide the same advantages or can be provided with the same embodiments as the seat as described above .

[0060] According to a fourth aspect, the present invention provides a method for influencing the shape of a main support surface of a support device , or an embodiment thereof as described above , wherein the method comprises the steps of : using the signals from the group of sensors to determine a distribution indicative of a force distribution over the area of the cover layer on top of the inflatable support element , inflating or deflating one or more of the inflatable support elements in order to adj ust the shape of the main support surface and / or to adj ust the distribution indicative of the forces exerted by a user to a desired shape and / or to provide a tis sue stimulation, posture correction, and / or a haptic feedback to a person supported by the support device .

[0061] Accordingly, the method of the present invention, in combination with the device of the present invention, inter alia allows to adj ust the shape of the main support surface to a suitable personal contour of a user, and at the same time provides a more comfortable feel to the user of the device of the present invention .

[0062] According to a fifth aspect, the present invention pertains to a computer-readable medium having computerexecutable instructions adapted to cause a device according to the first aspect of the invention as presented above , a set according to the second aspect of the invention as presented above , or a pillow, seat cushion or mattress according to the third aspect of the inventions as presented above, to perform a method according to the fourth aspect of the invention as presented above . Preferably the computer- readable medium comprises a non-transitory computer readable medium.

[0063] The various aspects and features described and shown in the specification can be applied, individually, wherever possible . These individual aspects , in particular the aspects and features described in the attached dependent claims , can be made subj ect of divisional patent applications .

[0064] BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings , in which :

[0066] Figure 1 schematically shows a part of a crosssection of a first example of a support device according to the present invention;

[0067] Figure 2 shows the same part of the cross-section of figure 1 when a person takes place on the device ;

[0068] Figure 3 schematically shows a part of a crosssection of a second example of a support device according to the present invention;

[0069] Figure 4 shows the same part of the cross-section of figure 3 when a person takes place on the device ;

[0070] Figure 5A schematically shows a top view of a first example of a car seat comprising a support device according to the present invention;

[0071] Figure 5B schematically shows a front view of a second example of a car seat comprising multiple support devices according to the present invention;

[0072] Figure 6 schematically shows a detail of the support device of figure 5A;

[0073] Figure 7A shows a schematic view of an example of a sensor for use in a support device of the invention;

[0074] Figure 7B shows a schematic cross-section view of an example of a sensor provided with a top and bottom plate ; and

[0075] Figure 8 schematically shows a block diagram of an example of a control device and the interconnections of the components of a support device according to the present invention .

[0076] DETAILED DESCRIPTION OF THE INVENTION

[0077] Figure 1 schematically shows a part of a crosssection of an example of a support device 1 according to the present invention . The support device 1 comprises a cover layer 2 which provides a main support surface 2 for the body of a person . On side of the cover layer 2 that faces away from a main support surface 3 , an auxiliary device 4 is arranged . The cross-section of figure 1 may be a part of a cross-section of a car seat, a pillow or a mattress , for example .

[0078] The auxiliary device 4 is configured for influencing the shape of the main support surface 3 and comprises a group of inflatable support elements 5 for supporting the main support surface . Each inflatable support element 5 comprises a sub-support surface 51 adj acent to the cover layer 2 . Furthermore , each inflatable support element

[0079] 5 of the group of support elements comprises bellows with a connector 6 for connecting a fluid supply tube 7 . The fluid supply tubes 7 are connected to a fluid control unit 8 . The fluid control unit 8 is fluidly connected to the connectors

[0080] 6 of the inflatable support elements 5 via the fluid supply tubes 7 , and is configured to selectively supply fluid under pressure to one or more inflatable support elements 5 of the auxiliary device 4 , and / or to selectively remove fluid from one or more inflatable support elements 5 . Preferably, the bellows of each inflatable support element 5 is made from a flexible fluid tight polymer material .

[0081] The inflatable support elements 5 are arranged next to each other in a plane substantially parallel to the main support surface 3 . The distribution of these inflatable support elements 5 over the area of the main support surface 3 may di ffer from one exemplary embodiment to another exemplary embodiment in order to provide an appropriate or desired support for a person on the support device 1 .

[0082] At a side of the auxiliary device 4 that faces away from the cover layer 2 , a group of sensors 9 is provided . Each sensor 9 of the group of sensors is associated with one inflatable support element 5 of the group of inflatable support elements . Furthermore, each sensor 9 is configured for sensing a force exerted on the respective inflatable support element 5. Each sensor 9 of the group of sensors is connected to the programmable control unit 10 via data leads 11 for providing signals that are indicative of the force exerted on the respective support elements 9.

[0083] The programmable control unit 10 is connected to the fluid control unit 8 via a data cable 12 which allows to control the inflating and / or deflating of the inflatable support elements 5, inter alia, based on the signals from the sensors 9 .

[0084] Furthermore, at a side of the auxiliary device 4 that faces away from the cover layer 2 , a padding layer 13 is arranged . The padding layer 13 provides additional cushioning when a person takes place on main support surface 3 of the support device 1 . It is noted that in the example of figure 1 , the sensors 9 are arranged in the preferred location between the inflatable support elements 5 and the padding layer 13 . The padding layer 13 in this example comprises a layer of materials such as latex foam, memory foam, viscoelastic or other flexible polyurethane foams .

[0085] Figure 2 shows the same part of the cross-section of the support device 1 of figure 1 when a person 20 takes place on the main support surface 3 of the support device 1 . As schematically shown, due to the weight of the person 20 , the padding layer 13 deforms to a certain extend . This initial deformation is one of the features of the support device 1 of the present invention, that provides a much more comfortable feel to a person 20 sitting or lying on the main support surface 3 .

[0086] The sensors 9 are fixedly connected to the corresponding inflatable support element 5 via a glue connection . This ensures that the sensors 9 stay in their position with respect to the inflatable support elements 5 , even when the padding layer 13 is deformed by the person 20 on the main support surface 3 .

[0087] In addition, the sensors 9 are placed under the respective inflatable support element 5 , as viewed from the main support surface 3 . Accordingly, the presence of the sensors 9 is substantially not felt by a person 20 that takes place on the main support surface 3 of the support device 1 of the invention, which also contributes to the more comfortable feel to the person 20 sitting or lying on the main support surface 3 .

[0088] As presented in the description of the invention, another feature of the support device 1 that provides a much more comfortable feel to a person 20 sitting or lying on the main support surface 3 is the use of the inflatable support elements 5 , which can much more easily deform when a person 20 takes place on main support surface 3 of the support device 1 of the invention . In addition, the inflatable support elements 5 further allow to adj ust the height and / or the amount of support of each one of the inflatable support elements 5 , for example , to adapt the main support surface 3 to the personal preference and / or demands of the person 20 using the support device 1 of the present invention . Accordingly, the inflatable support elements 5 allow to adj ust the contour of the main support surface 3 and / or the pressure distribution as experienced by the person 20 on the main support surface 3 to a personal preference and / or demand . In addition, the inflatable support elements 5 can be used for tissue stimulation, for example by applying a cyclic varying pressure pulsation to one or more of the inflatable support elements 5 in order to provide a massaging ef fect on at least part of the body of the person 20 that is in contact with the main support surface 3 .

[0089] Furthermore , the contour of the main support surface 3 and / or the pressure distribution can be adapted in order to initiate a posture correction to the person 20 that is sitting or lying on the main support surface 3 . In the case of sitting, this posture correction may for example comprises a pelvic tilt, a lower back rotation and / or a left / right or symmetric / a-symmetric back correction, by initiating an appropriate change in the shape of the support surface 3 by controlling the various inflatable support elements 5.

[0090] In addition to the areas of application above, the auxiliary device 4 can also be used to provide a haptic feedback for example for waking up a person 20 sitting or lying of the support device 1 by initiating a pressure pulsation in one or more of the inflatable support elements 5 to shake the person 20 awake . When applied in a car seat for example, the haptic feedback may in addition comprise , for example : changing the support of the person 20 as provided by the support device 1 when the case drives around a bend; providing a push or vibration signal to alert a driver for an unusual and / or dangerous situation on the road ahead; and / or changing the support of and / or providing a push or vibration signal to a driver to provide a hint or warning from the navigation system of the car .

[0091] It is noted that for dif ferent haptic feedbacks , the amplitude and / or the frequency of the change of the support and / or the push or vibration signal is preferably configured to be dif ferent for dif ferent haptic feedbacks , so that the person 20 sitting in the car seat can distinguish between the di fferent haptic feedbacks provided to said person 20 .

[0092] Figures 3 and 4 shown a second example of a support device 1 ' according to the invention . It is noted that the features in this second example which are the same as the corresponding features in the first example as described above, are provided with the same reference numbers .

[0093] Contrarily to the first example shown in figures 1 and 2 , the support device 1 ' of this second example has a padding layer 13 ' comprising a thinner foam layer 22 of materials such as latex, viscoelastic or other flexible polyurethane foams , and an additional elastic support layer 23 , for example a mesh base .

[0094] In addition, the foam layer 22 of this example also surrounds the auxiliary device 4 ' and at least at the circumference of the auxiliary device 4 ' , the foam layer 22 reaches up to the cover layer 2 . Accordingly, in this example , the auxiliary device 4 ' is imbedded in the foam layer 22 . Figures 3 and 4 also schematically show that the sensors 9 are arranged in a recess in the padding layer 13 which recess defines and position and keeps the sensors 9 in this position . Accordingly, in this example , the sensors 9 do not need to be fixedly connected to its associated inflatable support element 522 .

[0095] Furthermore , as schematically shown in figures 3 and 4 , the one or more of the inflatable support elements each comprises a stack of two bellows 521 , 522 arranged one behind the other in a direction from the cover layer 2 to the padding layer 13 ' . Accordingly, said stack of two bellows 521 , 522 , allows to increases the total available amplitude of said one or more o f the inflatable support elements for influencing the shape of the main support surface 3 . As schematically indicated, the internal volume of the two bellows 521 , 522 in a stack are in fluid connection with each other via the connectors 6 ' , 6" . Accordingly, only one fluid supply tube 7 is necessary for inflating and / or deflating these two stacked bellows 521 , 522 in a stack . Preferably, the bellows 521 , 522 of each inflatable support element are made from a flexible fluid tight polymer material .

[0096] Figure 4 shows the same part of the cross-section of the support device 1 ' of figure 3 when a person 20 takes place on the main support surface 3 of the support device 1 ' . As schematically shown, due to the weight of the person 20 , the padding layer 13 ' , in particular the foam layer 22 and the elastic support layer 23 , deforms to a certain extend . Again, this initial deformation is one of the features of the support device 1 ' of the present invention, that provides a much more comfortable feel to a person 20 sitting or lying on the main support surface 3 .

[0097] It is noted that in an alternative embodiment , the two bellows 521 , 522 of each inflatable support element may be provided with its own fluid supply line and its own control valves for selectively supplying and / or removing fluid from each one of the two bellows 521 , 522 separately . This allows , for example , to use one of the bellows 521 , 522 for adapting the contour of the main support surface 3 and / or the pressure distribution for supporting the person 20 , whereas the other one of the two bellows 521 , 522 is used for providing a haptic feedback and / or tissue stimulation .

[0098] All other features , characteristics and performance options of the support device 1 ' of this second example of figures 3 and 4 are similar or identical to the features , characteristics and performance options of the support device 1 of the first example in figures 1 and 2 as described above .

[0099] Figure 5A schematically shows a top view of a first example of a car seat 30 comprising a seat 31 , a seat back or backrest 32 and / or a headrest 33 . At least the seat 31 is provided with a support device 34 according to the present invention . The support device 34 is arranged under a cover layer of the seat 31 and thus are not visible from the outside of the car seat . The support device 34 in this example is provided with eight inflatable support elements BL1 - BL8 which are arranged in two rows of four inflatable support elements BL1 - BL4 , BL5 - BL8 in an area of the seat 31 near the backrest 32 that , in use , supports at least the pair of sitting bones of a person . In some embodiments of the support device 34 , a cross section along the line I-I of figure 5 is substantially similar to the example as shown in figure 1 or to the example as shown in figure 3 . Accordingly, the inflatable support elements BL5 - BL8 correspond to the inflatable support elements 5 in figure 1 or to the two bellows 521 , 522 of the inflatable support elements in figure 3 .

[0100] Figure 6 schematically shows a top view of the support device 34 of figure 5, wherein the inflatable support elements are combined in a first support assembly 36 comprising four inflatable support elements BL1 , BL2 , BL5 , BL6, arranged in a two-by-two arrangement around first centre point 38 , and a second support assembly 37 comprising four inflatable support elements BL3 , BL4 , BL7 , BL8 , arranged in a two-by-two arrangement around a second centre point 39. The two assemblies 36, 37 are arranged next to each other in a direction substantially parallel to a seat back 32 . The center point 38 , 39 of each assembly 36 , 37 is positioned for supporting one of the sitting bones of an average person , accordingly, the distance between the center points 38 , 39 of the two assemblies 36, 37 is in a range from 100 - 150 mm, preferably in a range from 110 - 140 mm.

[0101] In addition, the top view of figure 6 schematically shows the position and relative size of the sensors S I - S8 associated with and place under each of the inflatable support elements BL1 - BL8 .

[0102] Figure 5B schematically shows a second example of a car seat 30 ' , wherein the seat 31 comprises inflatable support members BL1 - BL8 (only the front four are schematically shown) in a similar manner as in the first example of figure 5A. In addition, the seat back 32 ' and / or the headrest 33 ' are also be provided with a support device according to the present invention . In particular, the seat back 32 ' comprises inflatable support members BL9 - BL15, and the headrest 33 ' comprises inflatable support members BL16, BL17 and BL18 . The additional support devices according to the present invention are preferably arranged to the lower part of the seat back 32 ' , adj acent to the seat 31 ' , this additional support device can assist and / or enhance the correction of the posture of the person sitting on the car seat 30 ' .

[0103] It is noted that the example of figures 5A, 5B and 6 refer to a car seat , but the arrangements shown and described above can also be applied in any seat that is used during longer term use , such as , for example, a seat in aviation for pilots and / or passengers , a motorbike seat or motorcycle saddle , a seat for train drivers and / or passengers , a seat for crew and / or passengers of a vessel , a control room seat, an office seat , a wheelchair, etc...

[0104] It is further noted that a seat according to the present invention may comprise the seat 31 only, thus without the back rest 32 and the headrest 33 , or the seat 31 with a back rest 32 , thus without the headrest 33 .

[0105] Figure 7A shows a schematic view of an example of a thin film sensor 70 for use in a support device of the invention . The sensor 70 is a thin film sensor, which preferably comprises a pressure sensitive material 71 , such as a piezoelectric material or a pressure sensitive ink, which is arranged in between two electrically conductive electrodes 72 , 73 , in particular a top electrode 72 and a bottom electrode 73 . It is noted that the bottom electrode 73 is not visible in figure 7 , as it is under the pressure sensitive material 71 , but has substantially the same shape as the top electrode 72 in this example . The bottom electrode 73 , the pressure sensitive material 71 and the top electrode 72 are arranged on a carrier foil 80 which is made from a substantially electrically isolating material . The top electrode 72 is electrically connected to a first connector pin 76 via a data wire 74 , and the bottom electrode 73 is electrically connected to a second connector pin 77 via a second data wire 75. Both the data wires 74 , 75 are arranged on top of an extension part 81 of the carrier foil 80 . The first and second connector pins 76, 77 , can be connected to one of the data leads 11 as shown in the arrangement of figures 1 - 4 .

[0106] In order to protect the thin film sensor 70 and to substantially evenly distribute the pressure or force applied to the thin film sensor 70 over the surface of the pressure sensitive material 71 , the thin film sensor 70 is sandwiched between a base plate 78 and a top plate 79, as schematically shown in the cross-section of Figure 7B . The base plate 78 is a substantially rigid base plate , and is in the examples of figures 1 - 4 arranged in contact with the padding layer 13 , 13 ' and provides a solid support surface for the sensor 70 . The top plate 79 is a substantially rigid top plate, and is in the examples of figures 1 - 4 arranged in contact with the associated inflatable support element 5. The top plate 79 provides a more stable and better distributed passing of the force on the inflatable support element 5 on the sensor 70 .

[0107] As schematically shown in figure 7B, the base plate 78 is provided with a rounded edge 781 at least at a side of extension part 81 where data leads 11 can be connected to the sensor 70 . The rounded edge 781 substantially prevents that the extension part 81 with the data wires 74 , 75 and / or the data leads 11 may get damaged on the edge of the base plate 78 .

[0108] Figure 8 schematically shows a block diagram of an example of a control device 100 and the interconnections of the components of the support device of figures 5 and 6, in particular the bellows of the inflatable support elements BL1 - BL8 , and the sensors S I - S 8 . It is noted that in the example of figure 8 , the inflatable support elements are arranged in a first support assembly 136 and a second support assembly 137 in a similar manner as depicted in figure 6 .

[0109] In order to control the inflatable support elements BL1 - BL8 , the control device 100 comprises a pump 101 which is connected to a first mani fold 102 and a second manifold 103 via a pressure line PL. The pump 101 is configured for supplying fluid under pressure via the pressure lines PL, preferably for supplying compressed air, to the first manifold 102 for supplying fluid under pressure to the inflatable support elements BL1, BL2, BL6, BL5 of the first support assembly 136, and to the second manifold 103 for supplying fluid under pressure to the inflatable support elements BL3, BL4, BL8, BL7 of the second support assembly 137.

[0110] The pressure lines PL in the first manifold 102 comprises a first series of valves VI, V2, V3, V4, which are configured for selectively providing a fluid connection between the pump 101 and one of the inflatable support elements BL1, BL2, BL6, BL5, and a second series of valves V5, V6, V7, V8, which are configured for selectively providing a fluid connection between an exit EXI, EX2, EX3, EX4 to the environment and said one of the inflatable support elements BL1, BL2, BL6, BL5. It is noted that in order to establish a fluid connection between the exit EX4 with the inflatable support element BL5 in this example, both the valves V4 and V8 need to be opened, which also depressurizes the pressure line PL. Dependent on whether the valves VI, V2, V3, V9, V10, Vll and V12 are also open or not, the inflatable support elements BL1, BL2, BL6, BL3, BL4, BL8 and / or BL7 are also depressurized or not.

[0111] The pressure lines PL in the second manifold 103 comprises a third series of valves V9, V10, Vll, V12, which are configured for selectively providing a fluid connection between the pump 101 and one of the inflatable support elements BL3, BL4, BL8, BL7, and a fourth series of valves V13, V14, V15, V16, which are configured for selectively providing a fluid connection between an exit EX5, EX6, EX7, EX8 to the environment and said one of the inflatable support elements BL3, BL4, BL8, BL7. Again it is noted that in order to establish a fluid connection between the exit EX8 with the inflatable support element BL7 in this example, both the valves V12 and V16 need to be opened, which also depressurizes the pressure line PL. Dependent on whether the valves VI, V2, V3, V4, V9, V10 and Vll are also open or not, the inflatable support elements BL1, BL2, BL6, BL5, BL3, BL4 and / or BL8 are also depressurized or not.

[0112] In addition, the control device 100 comprises a first pressure sensor 104 connected to the pressure line PL of the first manifold 102, and a second pressure sensor 105 connected to the pressure line PL of the second manifold 103. The first pressure sensor 104 can be brought in fluid communication with one or more of the inflatable support elements BL1, BL2, BL6, BL5 by opening the corresponding valve of the first series of valves VI, V2, V3, V4. The second pressure sensor 105 can be brought in fluid communication with one or more of the inflatable support elements BL3, BL4, BL8, BL7 by opening the corresponding valve of the third series of valves V9, V10, Vll, V12.

[0113] It is noted that in the example of figure 8, both the first and second pressure sensors 104, 105 are connected to the pressure line PL and substantially measure the same fluid pressure in the pressure line PL. Accordingly, the second pressure sensor 105 can act as a back-up for the first pressure sensor 104. However, by arranging additional valve (not shown) in the pressure line between the pump 101 and the first manifold 102, the first pressure sensor 104 can be used to measure the fluid pressure in the first manifold 102, independent on the fluid pressure in the pressure line PL near the pump 101 or the fluid pressure in the pressure line PL of the second manifold 103. Also, by arranging additional valve (not shown) in the pressure line between the pump 101 and the second manifold 103, the second pressure sensor 105 can be used to measure the fluid pressure in the second manifold 103, independent on the fluid pressure in the pressure line PL near the pump 101 or the fluid pressure in the pressure line PL of the first manifold 102.

[0114] The first pressure sensor 104 and / or the second pressure sensor 105 may be used for calibrating one or more of the sensors SI - S8, for example to correct for variations in the sensitivity of the sensors and / or to correct for an oblique or slanting orientation of the sensors SI - S8 , in particular the sensors arranged below the left or right side of a person on the support device of the invention, as for example schematically shown in figures 2 and 4 .

[0115] The control device 100 further comprises a valve control device 106 which is connected to each one of the valves VI - V16 by means of a control line CL, and is configured to control the working of each individual valve VI - V16. In addition, the control device 100 is connected to a programmable control unit 107 via a control command line CCL . Accordingly control of the working of each individual valve VI - V16 by the valve control device 106 is partially or wholly based on control commands from the programmable control unit 107 . As schematically shown in figure 8 , the programmable control unit 107 is also connected to the pump 101 via a pump control line PCL, and is configured to control the working of the pump 101 .

[0116] As schematically shown in figure 8 , the sensors SI - S 8 of each support assembly 136, 137 are each individually connected to a corresponding signal processing unit 108 , 109 via a signal line SL . The signal processing unit 108 , 109 in this example is configured to amplify the signals (preferably within a certain load range ) from the sensors SI - S8 and send the sensor signals to a sensor interface 110 which is connected to the signal processing units 108 , 109 via a data line DL . The sensor interface 110 is connected to the programmable control unit 107 via a sensor data line SDL for providing signals to the programmable control unit 107 that are indicative of the force or pressure exerted on the respective support elements BL1 - BL 8 as measured by the sensors S I - S8 .

[0117] Furthermore, as schematically shown in figure 8 , the programmable control unit 107 is connected to a Human- Machine Interface (HMI ) 111 , a power supply 112 , and a Universal Serial Bus (USB ) 113 .

[0118] In the example of figure 8 , the HMI comprises a display device 114 configured for displaying an image to a user, showing the amplitudes of the signals of the sensors ( S I - S8 ) , and / or the amount of inflation or the height of the respective support elements BL1 - BL8 . Preferably the display device 114 comprises a touch screen that in use provide a graphical interface which shows the control option and allows to select one or more of said control options . In addition, the touch screen allows to adj ust the settings of the support device , shows the selected settings , and / or provides feedback of the values measured by the sensor, preferably in a graphical way . When, for example, the support device of the present invention is provided in a car seat , the onboard touch screen of the car can provide the interface .

[0119] Furthermore, in the example of figure 8 , the USB is an interface for a programmers for debugging of the system.

[0120] It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention . In particular, the arrangement and / or distribution of the inflatable support elements in the support device of the above described and in the figures shown examples , is purely exemplary . From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention .

[0121] In summary, the invention relates to a support device for supporting a person, said support device comprising in sequence : a cover layer which provides a main support surface , an auxiliary device comprising a group of inflatable support elements for supporting and influencing the shape of the main support surface, a group of sensors , wherein one or more sensors of the group of sensors is associated with one inflatable support element of the group of inflatable support elements and is configured for sensing a force exerted on the respective inflatable support element by the person, and a padding layer .

[0122] The support device further comprises a fluid control unit which is configured to selectively supply fluid under pressure to one or more inflatable support elements , and a programmable control unit for controlling the support device .

Claims

C L A I M S1 . A support device for supporting a person, said support device comprising : a cover layer which provides a main support surface for the body of the person, an auxiliary device for influencing the shape of the main support surface, comprising a group of inflatable support elements for supporting the main support surface , wherein the inflatable support elements are positioned on the side of the cover layer that faces away from a main support surface , wherein each inflatable support element of the group of support elements comprises a connector for supplying and / or removing fluid in / out the inflatable support element, wherein each support element comprises a sub-support surface adj acent to the cover layer, a group of sensors , wherein one or more sensors of the group of sensors is associated with one inflatable support element of the group of inflatable support elements and is configured for sensing a force exerted on the respective inflatable support element by the person, wherein the sensors are arranged at a side of the respective inflatable support element facing away from the cover layer, a padding layer for providing cushioning, wherein the padding layer is arranged at a side of the auxiliary device facing away from the cover layer, a fluid control unit which is arranged in fluid connection with the connectors of the inflatable support elements and is configured to selectively supply fluid under pressure to one or more inflatable support elements of the auxiliary device, and / or to selectively remove fluid from one or more inflatable support elements , and a programmable control unit connected to the fluid control unit for controlling the fluid supply to and / or the fluid removal from one or more inflatable support elements of the auxiliary device, wherein the sensors of the group ofsensors are connected to the programmable control unit for providing signals to the programmable control unit that are indicative of the force exerted on the respective inflatable support elements .2 . The support device according to claim 1 , wherein each inflatable support element of the group of inflatable support elements is provided with its own associated one or more sensors of the group of sensors .3 . The support device according to claim 1 or 2 , wherein said one or more sensors of the group of sensors is arranged between its associated inflatable support element and the padding layer .4 . The support device according to claim 1 , 2 or 3 , wherein the one or more sensors are at least partially sunken or recessed into the padding layer .5 . The support device according to any one of the claims 1 - 4 , wherein the one or more sensors associated with an inflatable support element are connected to said inflatable support element , preferably fixedly connected to said inflatable support element .6 . The support device according to claim 5 , wherein the one or more sensors are concentrically connected to a side of the inflatable support element that facing away from the cover layer, preferably wherein a center line of the inflatable support element passes through a center of the one or more sensors .7 . The support device according to any one of the claims 1 - 6, wherein each sensor comprises a base plate at a side of the sensor facing away from the associated inflatable support element, preferably wherein the base plate is a substantially rigid base plate , preferably wherein thebase plate is provided with a rounded edge at least at a side where data leads connect to the sensor .8 . The support device according to any one of the claims 1 - 7 , wherein each sensor comprises a top plate at a side of the sensor facing towards the associated inflatable support element , preferably wherein the top plate is a substantially rigid top plate .

9. The support device according to any one of the claims 1 - 8 , wherein each sensor of said group of sensors is a thin film sensor, preferably wherein said thin film sensor comprises a piezoelectric material or a pressure sensitive ink .10 . The support device according to any one of the claims 1 - 9 , wherein the padding layer comprises a foam layer, preferably a layer of resilient polymer foam material .11 . The support device according to any one of the claims 1 - 10 , wherein one or more of the inflatable support elements of the group of inflatable support elements is surrounded by a padding layer part, at least in a plane substantially parallel to the cover layer, preferably wherein the padding layer parts extend towards and contact the cover layer .12 . The support device according to any one of the claims 1 - 11 , wherein the fluid control unit comprises a pump and a manifold, wherein the pump is connected to the mani fold and configured to supply fluid under pressure to the mani fold, and wherein the manifold is connected to the connectors of the inflatable elements and configured to selectively supply fluid under pressure to one or more inflatable elements of the auxiliary device, and / or to selectively remove fluid from one or more inflatableelements .13 . The support device according to claim 12 , wherein the mani fold comprises a series of valves , wherein each valve of said series of valves is configured for selectively providing a fluid connection between the pump and one of the inflatable support elements and / or between the environment and said one of the inflatable support elements , wherein the programmable control unit is connected to the mani fold and is configured to generated operational commands to the series of valves to achieve a desired pressure in each of the inflatable support elements of the auxiliary device .14 . The support device according to any one of the claims 1 - 13 , wherein the support device comprises a pressure sensor which is arranged in fluid communication with a fluid supply device and / or one or more of the inflatable support elements , preferably wherein the pressure sensor is arranged in fluid communication with one or more of the inflatable support elements via a valve .15 . The support device according to any one of the claims 1 - 14 , wherein the support device comprises a group of pressure sensors , wherein each pressure sensor of said group of pressure sensors is in fluid communication with at least one inflatable support element , wherein the pressure sensors of the group of pressure sensors are connected to the programmable control unit for providing signals that are indicative of the fluid pressure inside the respective inflatable support elements .16 . The support device according to any one of the claims 1 - 15 , wherein each one of the inflatable support elements comprises a bellows , preferably a bellows made from a flexible material .17 . The support device according to any one of the claims 1 - 16, wherein one or more of the inflatable support elements comprises two or more bellows arranged one behind the other in a direction from the cover layer to the padding layer .18 . The support device according to claim 17 , wherein the two or more bellows that are arranged one behind the other in the direction from the cover layer to the padding layer are configured such that their internal volume are in fluid connection with each other .19 . The support device according to any one of the claims 1 - 18 , wherein the support device comprises one or more support assemblies which are configured to work at least partially together, each support assembly comprising three or more inflatable support elements which are arranged in a plane substantially parallel to the cover layer, and around a center point, preferably wherein one or more of said assemblies comprises four inflatable support elements around the center point .20 . A seat , preferably a seat in a vehicle , vessel , airplane or a wheelchair, more preferably a car seat or a motorcycle saddle, provided with a support device according to any one of the claims 1 - 19 .21 . The seat according to claim 20 , when dependent on claim 19, wherein the support device comprises two support assemblies of inflatable support elements which are arranged in a plane substantially parallel to the cover layer, wherein the two assemblies are arranged next to each other in a direction substantially parallel to a seat back, preferably wherein each assembly is positioned for supporting one of the sitting bones of the person, more preferably wherein each assembly comprises two-by-two inflatable support elements .22 . The seat according to claim 20 or 21 , wherein the seat comprises a seat back and / or a headrest , wherein the seat back and / or the headrest is / are provided with a support device according any one of the claims 1 - 19.23 . A pillow, a seat cushion or a mattress provided with a support device according to any one of the claims 1 - 19.24 . A method for influencing the shape of a main support surface of a support device according to any one of the claims 1 - 19, wherein the method comprises the steps of : determining a measure of a force exerted on each inflatable support element by means of the group of sensors and establishing a force distribution over the area of the cover layer on top of the inflatable support element , inflating or deflating one or more of the inflatable support elements in order to adj ust the shape of the main support surface and / or to adj ust the distribution indicative of the forces exerted by a user to a desired shape and / or to provide a tis sue stimulation, posture correction, and / or a haptic feedback to a person supported by the support device .25 . Computer-readable medium having computerexecutable instructions adapted to cause a device according to any one of the claims 1 - 19, a seat according to any one of the claims 20 - 22 , or a pillow, seat cushion or mattress according to claim 23 , to perform a method according to claim 24 .

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