IES86137Y1 - Improvements in and relating to mattresses - Google Patents

Abstract

ABSTRACT The invention relates to a mattress assembly comprising a mattress 10 and a gas supply means wherein the mattress 10 comprises a plurality of chambers 30, 40 which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers 30, 40. Also provided are a mattress 10, an inflated mattress assembly and a cell 20 for use in a mattress 10.

Description

IMPROVEMENTS IN AND RELATING TO MATTRESSES FIELD OF INVENTION The present invention relates to mattresses, particularly, though not exclusively, to pressure relieving mattresses. to cells for mattresses, to mattress assemblies, to methods of controliing a gas pressure within mattresses and to controllers for controlling the operation of mattresses.

BACKGROUND TO THE INVENTION A recognised problem with persons having illnesses or injuries which necessitate them spending long periods of time in bed is that they can develop pressure sores and other complications. There are known a number of different types of pressure relieving mattresses which attempt to address this problem.

A known type of pressure relieving mattress comprises an expanded foam layer which is overlaid by two layers of air titled cells which extend in the side to side (lateral) direction of the mattress. The number of cells varies depending on the dimensions of the mattress but 15 to 50 cells per layer is typical. The cells are connected to a pump and a control unit and filled with air to support a person. The inflation of such mattresses is controlled in a manner which attempts to minimise the development of pressure sores by a person using such a mattress.

The cells can be arranged either in a single layer or two layers. Typically, in a two layer mattress the cells of the lower layer are maintained at a substantially constant (static) pressure whilst the cells of the upper layer are selectively inflated and deflated such that their pressure varies (is dynamic) so as to prevent a significant pressure being applied to any part of a persons body for a significant period of time. Such mattresses also typically comprise a number of cells which are perforated to allow air to flow from them. This can be useful in helping to circulate air around a persons body.

Whilst such pressure relieving mattresses can reduce the development of pressure sores they have a number of disadvantages. in particular. it can be difficult to control the inflation of the mattress to provide the best relief of pressure. In addition the construction of such mattresses is relatively complex. Accordingly, the present invention aims to address at least one disadvantage associated with the prior art whether discussed herein or otherwise. 886137 SUMMARY OF INVENTION According to a first aspect of the present invention there is provided a mattress wherein the mattress comprises a piurality of cells which are adapted to be inflated with a gas and wherein a number of such cells each comprise a first chamber separated from a second chamber by a dividing wall and wherein each of said first and second chambers is adapted to be inflated with a gas.

Suitably, the first and second chambers are adapted to be inflated with compressed air.

Suitably, each chamber comprises a gas inlet. Suitably, the gas inlet also serves as a gas outlet. Suitably, each chamber has a gas inlet pipe.

Suitably, all of the cells of the mattress comprise a first chamber separated from a second chamber by a dividing wall and wherein each of said first and second chambers is adapted to be inflated with a gas. Alternatively, a number of the cells may have a different construction.

Suitably. the cells of the mattress comprise a first chamber and a second chamber with a dividing well there between and the chambers have no internal baffles.

Suitably, the mattress comprises cells having a first chamber separated from a second chamber by a dividing wall and wherein each of said first and second chambers is adapted to be independently inflated with gas. Suitably. the mattress comprises cells having a first chamber separated from a second chamber by a dividing wall and wherein the gas pressure within each chamber can be independently controlled. Suitably, the mattress comprises cells having a first chamber separated from a second chamber by a dividing wall adapted such that there is no gas flow path between the chambers within the cell.

Suitably, the mattress comprises cells having a first chamber separated or partially separated from a second chamber by a dividing wall adapted such that there is a gas flow path between the chambers within the cell. Suitably, the mattress comprises cells having a first chamber and a second chamber with a dividing wall there between and which is adapted such that inflation of each of said first and second chambers is dependant on inflation of the other. Suitably, the mattress comprises cells having a first chamber and a second chamber with a dividing wall there between and which is adapted such that the gas pressure within each chamber is dependant on that in the other and can not be independently controlled.

Suitably, the mattress comprises a number of cells (i) having a first chamber separated from a second chamber by a dividing wall adapted such that there is no gas flow path between the chambers within the cell and a number of cells (ii) having a first chamber separated or partially separated from a second chamber by a dividing wall adapted such that there is a gas flow path between the chambers within the cell. Suitably, the mattress comprises regions of cells.

Suitably, the mattress has a head region and one or more other regions. Suitably, the cells in the head region are of type (ii). Suitably, the cells in other regions are of type (i). Suitably, the cells in all regions other than the head region are of type (i).

Suitably, the mattress has a head region, a foot region and a body region. Suitably, the mattress has a head region, afoot region and a number of body regions, suitably there are two or more, suitably three body regions.

Suitably, the mattress comprises a number of cells having a chamber with one or more vents in the cell wall. Suitably, the mattress comprises a number of cells having a ventilated second chamber with one or more vents in the cell wall. Suitably, the mattress comprises a number of cells having a chamber which does not have vents in the cell wall. Suitably, the mattress comprises a number of cells having a non-ventilated second chamber which does not have vents in the cell wall. Suitably, the mattress comprises a combination of cells having ventilated and non-ventilated chambers.

The mattress suitably comprises ventilated cells at the head region. The mattress suitably comprises ventilated cells at the foot region. The mattress suitabiy comprises ventilated cells in a central body region and non ventilated cells in body regions either side of the central body region.

Suitably, the mattress comprises between 20 and 40 cells. The mattress may comprise between 25 and 35 cells, for example 29 cells. Suitably, each cell comprises first and second chambers.

Suitably, the mattress comprises a plurality of cells according to the second aspect. The mattress may comprise one or more cells having any feature as described in relation to the second aspect.

Suitably, the mattress com prises a plurality of cells which are adapted to be inflated with a gas and wherein each cell comprises a first chamber separated from a second chamber by a dividing wall and wherein each of said first and second chambers is adapted to be inflated with a gas.

Suitably, the mattress comprises gas supply means to supply and remove gas from the chambers of the cells. Suitably, the gas supply means comprises a network of conduits.

Suitably, the gas supply means further comprises a pump. Suitably, the gas supply means further comprlses a controller to control the operation of the pump.

Suitabiy, the mattress is adapted such that the pressure of air within the chambers of a cell can be controlled differently depending on the location of the cell within the mattress. Suitably, the gas supply means is adapted to supply and remove gas from the chambers of the cells differently depending on the location of the cell within the mattress.

Suitably, the mattress is adapted such that the pressure within cell chambers can be varied independently of the pressure within other cell chambers. Suitably, the mattress is adapted such that the pressure within cell chambers can be varied simultaneously with variation of the pressure within other cell chambers.

Suitably, the mattress comprises a pressure relieving mattress. Suitably, the mattress is adapted for use as an alternating pressure mattress.

Suitably, the mattress comprises emergency deflation means for releasing gas from chambers of cells of the mattress if it is necessary to perform resuscitation on a person supported by the mattress in use.

Suitably, the emergency deflation means comprises an aperture in a conduit of a gas supply means of the mattress which is sealed by a plug and which plug can be removed to allow rapid egress of gas from the conduit and thus the chambers of the cells of the mattress in an emergency.

Suitably, the emergency deflation means is located proximal to a region of the mattress which is adapted to support the torso of a person in use. Thus. on activation of the emergency deflation means air may first exist the cells of the mattress supporting a persons torso, this may allow effective resuscitation to be commenced whilst air is still exiting the remaining cells of the mattress.

Suitably, the emergency deflation means is located between the end and 1/2 way aiong the tength of the mattress when measured from the head end of the mattress. Suitably, the emergency deflation means is located between 1/5 and 1/2 of the length of the mattress when measured from the head end of the mattress.

Suitably, emergency deflation means are located on both sides of the mattress.

Suitably, the mattress comprises a layer of foam. Suitably, the mattress comprises a layer of expanded foam. Suitably, the mattress comprises a base layer of expanded foam and a layer of cells lies above the base in use.

Suitably, the mattress comprises a casing adapted to enclose the cells. Suitably, the mattress comprises a casing adapted to enclose the cells and gas supply conduits feeding gas to and taking gas from the cells. Suitably, the mattress comprises a casing adapted to enclose a layer of foam. Suitably, the casing comprises a first compartment adapted to receive a layer of cells. Suitably, the casing comprises a second compartment adapted to receive a sheet of foam. Suitably, said compartments have zip closures.

The mattress suitably comprises a casing having a detachable cover which can be unzipped from the remainder of the casing. Suitably, the casing comprises a flap to cover the zip.

Suitably, the cells can be individually removed from the mattress and replaced if they become damaged. Suitably, the cells have means to secure them in position relative to the mattress casing. Suitably the cells are adapted to be secured to the casing by securement means on one or both ends of the cell. Suitably, the securement means comprise a pepper, suitably by a popper on each end of the cell.

Suitably. the mattress comprises two pipes for connecting to a gas supply means and the two ends can be connected to one another to retain air in the mattress if it is detached from a gas supply means.

Suitably, the mattress is adapted to be operated according to the method of the sixth aspect.

The mattress may comprise any feature as described in relation to the sixth aspect.

Suitably, the mattress is adapted such that a bed can be adjusted or profiled with the mattress in position.

According to a second aspect of the present invention there is provided a cell for use in a mattress wherein the cell is adapted to be inflated with a gas and comprises a first chamber separated from a second chamber by a dividing wall with each of said first and second chambers being adapted to be inflated with a gas.

Suitably, the first and second chambers are adapted to be inflated with compressed air.

The cell is suitably adapted such that the first chamber and second chamber can be inflated with gas independently of one another. The cell is suitably adapted such that the pressure of gas within the first chamber and second chamber can be controlled independently of one another.

Suitably, the cell comprises only two chambers. Suitably, in use, the first chamber is adapted to lie below the second chamber. Suitably, the cell comprises a dividing wall which substantially divides the cell in two to form a first lower chamber and a second upper chamber.

Suitably, the cell is adapted to extend in the side to side direction of a mattress in use. The cell may thus be adapted to extend laterally in a mattress of which it forms a part in use.

Suitably, the dividing wall of the cell extends in a side to side direction of a mattress in use.

Suitably, in use, when the mattress is orientated to lie horizontally and the cell is inflated the dividing wall will extend substantially horizontally.

Suitably, the cell comprises a dividing wall formed from a gas impermeable material. Suitably, the cell comprises a dividing wall formed from a material which is substantially impermeable to nitrogen and oxygen (the major constituents of air).

The cell may comprise a dividing wall which is impermeable to nitrogen and oxygen. The cell is suitably adapted such that a gas can not flow between the first chamber and the second chamber without first exiting the cell. The cell is suitably adapted such that nitrogen and oxygen can not flow between the first chamber and the second chamber without first exiting the cell.

Suitably, the cell comprises an outer wall fonned from a gas impermeable material. Suitably, the cell comprises an outer wall formed from a material which is substantially impermeable to nitrogen and oxygen (the major constituents of air).

The cell may comprise an outer wall which is impermeable to nitrogen and oxygen.

Alternatively, the cell may comprise an outer wall having one or more perforations therein. The cell may for example comprise one or more perforations in the outer wait of the second chamber. The cell may comprise one or more perforations adapted to allow air to vent to circulate around a person supported by a mattress of which the cell forms a part in use.

The cell may comprise an outer wali formed from two pieces of material sealed to one another along their edges. The cell may comprise an outer wall fonned from two pieces of material sealed to one another along their upper and lower edges. The cell may comprise an outer well formed from two pieces of material welded to one another along their edges. The cell may comprise an outer wall formed from a piece of material folded in two and sealed to itself along its edges. The cell may comprise an outer wall formed from a piece of material folded in two and sealed to itself along its lower edge. The cell may comprise a folded piece of material welded to itself along its edges.

The cell may comprise a dividing wall which is sealed to an outer wall. The cell may comprise a dividing wall which is formed from a piece of material sealed to an outer wall along opposed edges of said piece of material. The cell may comprise a dividing wall which is formed from a piece of material which is welded to an outer wall along opposed edges of said piece of material.

Suitably, the cell comprises an aperture in the first chamber to provide a gas inlet and/or outlet thereto. Suitably, the first chamber comprises a single aperture providing both a gas inlet and outlet. Suitably, the aperture is provided at an end of the cell.

Suitably, the cell comprises an aperture in the second chamber to provide a gas inlet and/or outlet thereto. Suitably, the second chamber comprises a single aperture providing both a gas inlet and outlet. Suitably, the aperture is provided at an end of the cell.

Suitably, the first and second chamber each comprise an aperture providing a gas iniet and outlet and said apertures are located at the same end of the call such that in use they lie on one side of a mattress.

Suitably. the cell comprises a first chamber and a second chamber with a dividing wall there between and the chambers have no internal baffles.

Suitably, the cell has a first chamber separated from a second chamber by a dividing wall adapted such that there is no gas flow path between the chambers within the cell.

The cell may have a first chamber separated or partially separated from a second chamber by a dividing wall adapted such that there is a gas flow path between the chambers within the cell.

The cell may comprise any feature as described in relation to a cell of the first aspect.

According to a third aspect of the present invention there is provided a mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a pluraiity of chambers which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers and wherein said mattress assembly: (i) comprises only two pipes connecting the mattress to a pump; and/or (ii) is adapted to allow measurement oi the pressure under the patient; and/or (iii) is adapted to provide the ability to adjust pressure around a pre-set value in both static and dynamic modes of operation; and/or (iv) is adapted to automatically reduce pressure when switching from a dynamic mode to a static mode and/or to automatically increase pressure when switching from a static mode to a dynamic mode; and/or (v) is adapted to self calibrate a measured pressure.

Suitably, there is provided a mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a plurality of chambers which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers and wherein said mattress assembly comprises only two pipes connecting the mattress to a pump.

Suitably, there is provided a mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a plurality of chambers which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers and wherein said mattress assembly is adapted to allow measurement of the pressure under the patient.

Suitably, there is provided a mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a plurality of chambers which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers and wherein said mattress assembly is adapted to provide the ability to adjust pressure around a pre-set value in both static and dynamic modes of operation.

Suitably, there is provided a mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a plurality of chambers which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers and wherein said mattress assembly is adapted to automatically reduce pressure when switching from a dynamic mode to a static mode and/or to automatically increase pressure when switching from a static mode to a dynamic mode Suitably, there is provided a mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a plurality of chambers which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers and wherein said mattress assembly is adapted to self calibrate a measured pressure.

Suitably, the chambers are adapted to be inflated with com pressed air.

Suitably, the gas supply means comprises a pump. Suitably, the gas supply means comprises an air compressor.

Suitably, the assembly comprises a valve for controlling the flow of gas from a compressor to the mattress. Suitably, the assembly comprises a valve controlled by a controller to control the pressure within chambers of cells of the mattress.

Suitably, the valve is adapted to control the flow of gas into and out of the chambers of cells of the mattress. Suitably, the valve is located adjacent a compressor of the assembly. Suitably, the valve controls the flow of gas through two pipes which suppty gas from the compressor to the mattress.

Suitably, the assembly comprises means for a user to control settings for the gas pressure within the mattress. Suitably, the assembly comprises means to display information regarding the gas pressure within the mattress to a user.

Suitably, the controller is adapted to vary the pressure of a gas within gas filled chambers of said mattress.

Suitably, the controller is adapted to control the pressure of a gas within gas filled chambers of said mattress according to a number of predetennined settings which can be selected between by a user.

Suitably, the assembly comprises a controller having a PCB (printed circuit board) adapted to control the pressure within chambers of the cells of the mattress according to predetermined settings.

Suitably, controller is adapted to vary the pressure within chambers according to predetermined pressure cycles. Suitably, the controller is adapted to allow a user to manually input changes to the controlled pressure to vary it from the predetermined settings and/or cycles.

Suitably, the controller has predetermined modes of operation which can be activated by a user. Suitably, the controller is adapted to allow user settings to be inputted in addition to predetermined settings. The predetermined modes of operation may thus be combined with user settings to provide a bespoke operation.

The controller suitably has a static mode in which the pressure within gas filled chambers of the mattress is kept substantially constant for a period of time. Suitably, said period of time is at least 1 minute, for example 5 minutes or more and said period of time may suitably last until a user changes a setting of the controller.

The static mode may have pre-set comfort settings corresponding to different gas pressures.

Suitably, there are pre-set comfort settings of soft, medium and firm.

Suitably, in the static mode if the soft comfort setting is chosen the pre-set pressure the controller adjusts the pressure to be is around 15mmHg. Suitably, by a user modifying the pressure around the pre-set soft comfort setting the pressure can be set between 15mmHg and 19mmHg.

Suitably, in the static mode it the medium comfort setting is chosen the pre-set pressure the controller adjusts the pressure to be is around 20mmHg. Suitably, by a user modifying the pressure around the pre-set medium comfort setting the pressure can be set between 20mmHg and 24mmHg.

Suitably, in the static mode if the firm comfort setting is chosen the pre-set pressure the controller adjusts the pressure to be is around 25mmHg. Suitably, by a user modifying the pressure around the pre-set firm comfort setting the pressure can be set between 25mmHg and 29mmHg.

The controller suitably has a dynamic mode in which the pressure within at least some gas filled chambers of the mattress is varied over a period of time. Suitably, said period of time is at least 1 minute, for example 5 minutes or more and said period of time may suitably last until a user changes a setting of the controller.

Suitably, in the dynamic mode the controller causes the pressure within at least some gas filled chambers to be varied over a predetennined cycle time following which the cycle repeats.

Suitably, the cycle time is between 1 minute and 60 minutes. Suitably, the controller has a number of pre-set‘ cycle times. Suitably, the pre-set cycle times are 5, 10, 15 or 20 minutes.

Suitably, the mattress comprises a layer of first lower chambers and a layer of second upper chambers. Suitabiy, the mattress comprises regions of chambers. Suitably, the controller is adapted such that in the dynamic mode the pressure within the chambers of the lower layer remains substantially constant. Suitably, the controller is adapted such that in the dynamic mode the pressure within the chambers of the head region of the upper layer remains substantially constant. Suitably, the controller is adapted such that in the dynamic mode the pressure within the chambers of the upper layer is varied in all regions of the mattress other than the head region.

Suitably, the controller is adapted such that the dynamic mode comprises an alternating mode.

Suitably the mattress comprises groups of chambers in the upper layer and the dynamic mode comprises increasing the pressure within one group as it is decreased within another.

Suitably, the mattress comprises two groups of chambers in the upper layer. Suitably. the groups are arranged in an alternating pattern. The mattress may for example comprise chambers arranged in groups A and B in a repeating pattern ABABAB.

Suitably, in the dynamic mode at least 90% of the chambers of the mattress are at least partially inflated. Suitably, in the dynamic mode all the chambers of the mattress are at least partially inflated.

The dynamic mode may have pre-set comfort settings corresponding to different gas pressures. Suitably, there are pre-set comfort settings of soft. medium and firm.

Suitably. in the dynamic mode, if the soft comfort setting is chosen the pre-set pressure the controller adjusts the maximum pressure chambers are inflated to be is around 20mmHg.

Suitabiy, by a user modifying the pressure around the pre-set soft comfort setting the maximum pressure chambers are inflated to can be set between 20mmHg and 29mmHg.

Suitably, in the dynamic mode if the medium comfort setting is chosen the pre-set pressure the controller adjusts the maximum pressure chambers are inflated to be is around 30mmHg.

Suitably, by a user modifying the pressure around the pre-set medium comfort setting the maximum pressure chambers are inflated to can be set between 30mmHg and 39mmHg.

Suitably, in the dynamic mode if the linn setting is chosen the preset pressure the controller adjusts the maximum pressure chambers are inflated to be is around 40mmHg. Suitably, by a user modifying the pressure around the pre-set firm comfort setting the maximum pressure chambers are inflated to can be set between 40mmHg and 49mmHg.

Suitably, the controller is adapted such that the pressure within chambers of the mattress is automatically reduced if a user switches the controller from a dynamic mode to a static mode.

Suitably. the controller is adapted such that the pressure within chambers of the mattress is automatically increased if a user switches the controller from a static mode to a dynamic mode.

Suitably, if a user switches from the dynamic mode to the static mode or vice versa the controller is adapted to adjust the pressure to that of the corresponding comfort setting in the mode which is being switched to. If a user has varied the pressure from a pre-set pressure setting then the controller is suitably adapted to take that into account when switching between the dynamic and static modes such that the pressure in the mode which is switched to will also be varied from the pre-set pressure in that mode.

The controller suitably has a dual mode. In the dual mode the controller may switch between operating the mattress in a static mode and a dynamic mode. The controller may switch between static and dynamic modes at regular intervals, suitably hourly. The controller may be adjusted to automatically adjust the pressure in the mattress as it switches between modes.

The controller suitably has a nursing mode. In the nursing mode the controller may cause the chambers of the cells of the mattress to be inflated to a pressure of 40mmHg or more. suitably of 49mmHg or more, for example 50mmHg or more. Suitably, the controller is adapted to revert to the mode the mattress was previously in before the nursing mode was chosen after a given period of time. Suitably, the nursing mode has a preset duration, for example up to 30 minutes.

The controller may be adapted to switch from the static mode to the dynamic mode after a predetermined time. The controller may be adapted to switch to the dynamic mode after the static mode has been in operation for one hour.

Suitably, the controller has a low pressure alarm. Suitably, the controller has a power failure alarm.

Suitably, the controller is adapted to allow the actual pressure of gas within the mattress to be displayed. Suitably, the controller has a lock mode to prevent a user inadvertently adjusting the settings. Suitably, when in the lock mode the controller can display the actual gas pressure.

Suitably, the controller is adapted to autom aticaiiy adjust the pressure and is unaffected by the users size or weight.

Suitably, the mattress comprises a plurality of cells which are adapted to be inflated with a gas and wherein a number of such cells each comprise a first chamber separated from a second chamber by a dividing wall and wherein each of said first and second chambers is adapted to be inflated with a gas.

Suitably, the mattress comprises a mattress according to the first aspect. The mattress assembly may comprise any feature as described in relation to the mattress of the first aspect.

Suitably, the mattress comprises a plurality of cells according to the second aspect.

Suitably, the mattress assembly is adapted to be operated according to the method of the sixth aspect. The mattress assembly may comprise any feature as described in relation to the sixth aspect.

According to a fourth aspect of the present invention there is provided a mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a plurality of chambers which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers and wherein said mattress assembly comprises a mattress according to the first aspect.

The mattress assem bly may comprise a mattress assembly according to the third aspect.

Suitably, the mattress assembly is adapted to be operated according to the method of the sixth aspect. The mattress assembly may comprise any feature as described in relation to the sixth aspect.

According to a fifth aspect of the present invention there is provided an infiated mattress assembly comprising a mattress according to the first aspect and/or a mattress assembly according to the third or fourth aspects and wherein said mattress and/or mattress assembly comprises a plurality of chambers inflated with a gas.

Suitably, the chambers are inflated with air.

According to a sixth aspect of the present invention there is provided a method of controlling a gas pressure within a mattress wherein the method employs a mattress according to the first aspect and/or a mattress assembly according to the third or fourth aspects.

Suitably, the method comprises supporting a person on a mattress.

Suitably, the method is adapted to minimise the development of pressure sores by a person supported by said mattress.

Suitably, the method comprises varying the pressure of a gas within gas filled chambers of said mattress.

Suitably, the method employs a controller for controlling the pressure within gas filled chambers of said mattress. Suitably, the controller has predetermined modes of operation which can be activated by a user. Suitably, the controller is adapted to allow user settings to be inputted in addition to predetermined settings. The predetermined modes of operation may thus be combined with user settings to provide a bespoke operation.

The method may comprise operating the mattress in a static mode in which the pressure within gas filled chambers of the mattress is kept substantially constant for a period of time. Suitably, said period of time is at least 1 minute, for example 5 minutes or more and said period of time may suitably last until a user changes a setting of the controller.

Suitably, in the static mode at least 90% of the chambers of the mattress are at least partially inflated. Suitably, in the static mode all the chambers of the mattress are at least partially inflated. Suitably, In the static mode at least 90% of the chambers of the mattress are fully inflated. Suitably, in the static mode all the chambers of the mattress are fully inflated.

Suitably, in the static mode the pressure within at least 90% of the chambers of the mattress. suitably within all chambers is at least 16mmHg. The static mode may have pre-set comfort settings corresponding to different gas pressures. Suitably, there are pre-set comfort settings of soft, medium and firm.

Suitably, in the static mode if the soft comfort setting is chosen the pressure within at least 90% of the chambers, suitably within all chambers is around 15mmHg. Suitably, a user may use the controller to modify the pressure around the pre-set pressure. Suitabiy. by a user modifying the pressure around the pre-set soft comfort setting the pressure can be set between 15mmHg and 19mmHg.

Suitably, in the static mode if the medium comfort setting is chosen the pressure within at least 90% of the chambers, suitably within all chambers is around 20mmHg. Suitably, a user may use the controller to modify the pressure around the pre-set pressure. Suitably, by a user modifying the pressure around the pre-set soft comfort setting the pressure can be set between 20mmHg and 24mrnHg.

Suitably, in the static mode if the soft comfort setting is chosen the pressure within at least 90% of the chambers, suitably within all chambers is around 25mmHg. Suitably, a user may use the controller to modify the pressure around the pre-set pressure. Suitably. by a user modifying the pressure around the pre-set soft comfort setting the pressure can be set between 25mmHg and 29mrnHg.

The method may comprise operating the mattress in a dynamic mode in which the pressure within at least some gas filled chambers of the mattress is varied over a period of time.

Suitably, said period of time is at least 1 minute, for example 5 minutes or more and said period of time may suitably last until a user changes a setting of the controller.

Suitably, the dynamic mode comprises varying the pressure within at least some gas filled chambers over a predetermined cycle time following which the cycle repeats. Suitably, the cycle time is between 1 minute and 60 minutes. Suitably, a user can select the cycle time from one of a number of preset times. Suitably, the cycle time can be set to be 5, 10, 15 or 20 minutes.

Suitably, the mattress comprises a layer of first lower chambers and a layer of second upper chambers. Suitably, the mattress comprises regions of chambers. Suitably, in the dynamic mode the pressure within the chambers of the lower layer remains substantially constant.

Suitably, in the dynamic mode the pressure within the chambers of the head region of the upper layer remains substantially constant. Suitably, in the dynamic mode the pressure within the chambers of the upper layer is varied in all regions of the mattress other than the head region.

Suitably, the dynamic mode comprises an alternating mode. Suitably the mattress comprises groups of chambers in the upper layer and the dynamic mode comprises increasing the pressure within one group as it is decreased within another. Suitably, the mattress comprises two groups of chambers in the upper layer. Suitably. the groups are arranged in an alternating pattern. The mattress may for example comprise chambers arranged in groups A and B in a repeating pattern ABABAB.

Suitably, in the dynamic mode at least 90% of the chambers of the mattress are at least partially inflated. Suitably, in the dynamic made all the chambers of the mattress are at least partially inflated. in the dynamic mode the average pressure within at least 90% of the chambers of the mattress, suitably within all chambers is at least 16mmHg. The dynamic mode may have pre- set comfort settings corresponding to different gas pressures. Suitably, there are pre-set comfort settings of soft, medium and firm.

Suitably, in the dynamic mode if the soft comfort setting is chosen the maximum pressure chambers are inflated to is around 20mmHg. Suitably. a user may use the controller to modify the pressure around the pre-set pressure. Suitably, by a user modifying the pressure around the pre-set soft comfort setting the maximum pressure chambers are inflated to can be set between 20mmHg and 29mmHg.

Suitably, in the dynamic mode if the medium setting is chosen the maximum pressure chambers are inflated to is around 30mmHg. Suitably, a user may use the controller to modify the pressure around the pre-set pressure. Suitably, by a user modifying the pressure around the pre-set medium comfort setting the maximum pressure chambers are inflated to can be set between 30mmHg and 39mmHg.

Suitably, in the dynamic mode if the firm setting is chosen the maximum pressure chambers are inflated to is around 40mmHg. Suitably, a user may use the controller to modify the pressure around the pre-set pressure. Suitably, by a user modifying the pressure around the pre-set firm comfort setting the maximum pressure chambers are inflated to can be set between 40mml-lg and 49mmHg.

The method may comprise operating the mattress in a dual mode. In the dual mode the controller may switch between operating the mattress in a static mode and a dynamic mode.

The controller may switch between static and dynamic modes at regular intervals, suitably hourly.

The method may comprise operating the mattress in a nursing mode. In the nursing mode the controller may cause the chambers of the cells of the mattress to be inflated to a pressure of 40mmHg or more, suitably of 49mmHg or more, for example 50mmHg or more. Suitably, the controller is adapted to revert to the mode the mattress was previously in before the nursing mode was chosen after a given period of time. Suitably, the nursing mode has a preset duration, for example up to 30 minutes.

The method may comprise the assembly automatically switching from a static mode to a dynamic mode after a predetermined time. The method may comprise switching to the dynamic mode after the static mode has been in operation for one hour.

The method suitably comprises using a pump having only two pipes to inflate and deflate chambers of the mattress.

The method suitably comprises determining the pressure under a person supported by the mattress. The method suitably comprises determining the gas pressure within gas filled chambers of the mattress. The method may comprise measuring the pressure under a person supported by the mattress. The method may comprise measuring the gas pressure within gas filled chambers of the mattress. The method may comprise measuring the pressure within part of the gas supply means connected to the mattress and using that to determine the pressure under a person supported by the mattress. The pressure measurement may be made by an electrical component on a PCB of the controller.

Suitably, the controller comprises predetermined pressure settings for controlling the pressure within chambers of the mattress. Suitably. the controller is adapted to allow a user to adjust the controlled pressure from the predetermined setting. The controller may be adapted to provide a user with the ability to adjust pressure around or above a stated nominal value for both static and dynamic modes.

Suitably, the controller is adapted to automatically reduce pressure within chambers of the mattress when switching from dynamic to static modes. Suitably. the controller is adapted to automatically increase pressure within chambers of the mattress when switching from static to dynamic modes.

Suitably, the controller is adapted to self calibrate the measured pressure. The controller may be adapted to seif calibrate the measured pressure in response to a user selecting a combination of buttons.

According to a seventh aspect of the present invention there is provided a controller for controlling the operation of a mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a plurality of chambers which are adapted to be inflated with gas and wherein the controller is adapted to control the pressure of gas within said chambers and wherein said controller: (i) is adapted to control the pressure using a pump having only two pipes connecting to the mattress; and/or (ii) is adapted to allow measurement of the pressure under the patient: and/or (iii) is adapted to provide the ability to adjust pressure around a pre-set value in both static and dynamic modes of operation; and/or (iv) is adapted to automatically reduce pressure when switching from a dynamic mode to a static mode and/or to automatically increase pressure when switching from a static mode to a dynamic mode; and/or (v) is adapted to self calibrate a measured pressure.

Suitably, the controller comprises any feature as described in relation to the third, fourth or sixth aspects.

BRIEF DESCRIPTION OF DRAWINGS The present invention will now be illustrated by way of example with reference to the accompanying drawings in which: Figure 1 shows a mattress of a mattress assembly; Figure 2 shows a mattress and gas supply pipes of a mattress assembly; Figure 3 shows a cell of a mattress; Figure 4 shows a cross section of the cell of Figure 3; Figure 5 shows a controller front of a mattress assembly; and Figure 6 shows components of a gas supply means of a mattress assembly.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS As illustrated by Figures 1 and 2 a mattress assembly comprises a mattress to which comprises twenty nine cells 20.

The mattress 10 comprises regions of ceiis 20. The mattress 10 has a head region H a foot region F and three body regions B1, B2, B3 with B2 being the central body region.

Each cell in regions B1, B2, B3 and F has a construction as shown by Figures 3 and 4 comprises a first lower chamber 30 and a second upper chamber 40. The chambers are separated from one another by a dividing wall 50. The cell comprises an outer wall 60 comprising a sheet of material which is folded and welded along its edges. The dividing wall 50 is welded to the outer wall 60. The cell 10 further comprises pipes 70, 80 providing gas inlets to the chambers 30, 40. At the ends of the cell are peppers 90 by which it can be secured to a casing of the mattress (not shown).

The cells 20 in regions 82 and F also comprise small apertures in the upper chamber 40 wall 60 (not shown) such that they are ventilated and allow gas to exit from them. in regions B1, B2, B3 and H the dividing wall 50 of the cell is such that there is no gas fiow between the upper and lower chambers. The cells 20 in the head region H differ from those in other regions in that the dividing wall comprises a break such that gas can flow between the upper and lower chambers. The cells 20 in the head region H also only have an air inlet to the upper chamber. Othenivise, the cells in the head region H correspond to those in other regions. The cells in the head region H comprise small apertures (pinholes) in the upper chamber 40 wall 60 (not shown) such that they are ventilated and allow gas to exit from them.

As illustrated by Figure 2 the cells 20 are fed with gas by gas supply pipes 90, 100 which are fed with compressed air from a compressor. Each pipe has a non-return valve 110, 120 located before the feed to the head region H. The pipes 90, 100 also allow gas to be removed from the cells 20.

The mattress assembly further comprises a casing (not shown) and a layer of foam (not shown). The casing has a zipped pocket for holding the sheet of foam. The casing has a detachable top cover which zips to the remainder of the casing to form a pocket to hold the cells 20 and the gas supply pipes 90, 100. The gas supply pipes 90, 100 comprise flexible hoses and the casing may help to protect these and keep them tidy.

The flow of gas into and out of chambers of the cells 20 is controlled by a controller which controls a valve connected to the gas supply pipes 90. 100. Depending on the valve setting the pipes 90, 100 can convey gas to or from chambers of the cells 20.

The upper chambers 40 of the cells 20 in regions B1, B2, B3 and F are arranged in groups in an alternating pattern with those of the first group being connected to the gas supply pipe 90 and those of the second group being connected to the gas supply pipe 100. This arrangement allows gas to be introduced into one group of chambers as gas is removed from the other group and vice versa.

The mattress assembly has a number of modes of operation including a dynamic mode. This dynamic mode comprises an alternating mode. As noted, the mattress comprises groups of chambers in the upper layer and the alternating mode comprises increasing the pressure within one group (connected to pipe 90) as It is decreased within the other group (connected to pipe 100). The assembly is adapted such that adjacent chambers of the upper layer inflate and deflate in a cyclical manner so that different body parts of a person supported by a mattress contact it at different times.

The mattress assembly is adapted such that the pressure in the upper chambers of the cells at the head region H remains substantially constant in the alternating mode.

The mattress assembly also has a static mode of operation in which the pressure within ceils of the mattress 10 is kept substantially constant. in both the static and dynamic modes the mattress assembly has three pre-set comfort settings, soft, medium and firm which correspond to different pressures to which the chambers of the cells 20 are inflated. The controller is also adapted to allow a user to vary the pressure from the pre-sets to tailor it to the needs of a person supported by the mattress.

The controller is adapted to automatically cause the gas pressure within chambers of cells 20 of the mattress to to decrease when it is switched from the dynamic to the static mode and to automatically cause the gas pressure within chambers of cells 20 of the mattress to to increase when it is switched from the static to the dynamic mode.

The mattress assembly also has a dual mode of operation in which it operates in a static mode for a 1 hour period and then in a dynamic mode for one hour and so on.

The mattress assembly also has a nursing mode in which the gas pressure within the mattress cells 20 is increased to provide a firm er bed making it easier for medical care to be administered. The controller is adapted to revert to the mode and pressure it was at before the nursing mode was chosen 30 minutes after the nursing mode is chosen.

The pressure within the cells of the mattress assembly is controlled using a controller 140 having a user input and display means 150 as shown in Figure 5.

Components of the gas supply means are as shown in Figure 6 and comprise a power input 160, a transformer 170, a control PCB 180 of the controller, an air compressor 190 and a rotor valve 200 which feeds air to the pipes of the mattress 10.

The valve 200 is operated by the controller and controls inflation and deflation of chambers of the cells 20 of the mattress 10.

The mattress can be operated in a number of modes. The features of the user input and display means 150 and operation of the controller are detailed below.

The On/Standby button 210. when the green indicator is on, this means that the power unit starts to operate. when the orange indicator is on, this means that the unit stands by and does not operate.

Comfort Setting 220. Select the green indicators for a soft, medium or firm setting. The power unit automatically adjusts and shifts to the most appropriate pressure depending on the selected setting. This function can be used to adjust the comfort level around the preset levels for 8 (Soft) , M (Medium) and F (Firm). Soft = 20mmHg, Medium = 30 mmHg, and Firm .-. 40mmHg in the alternating (dynamic) mode. The arrows up 230 and down 240 will allow for manual adjustment 21 -29, 31-39 and 41-49 respectively.

Alternating Mode 250. This feature allows body tissues to be temporarily relieved of pressure and blood to circulate smoothly around the tissues in a time scale depending on the cycle selected. This in turn may heal. improve and prevents the occurrence of pressure ulcers.

Select the green indicators for 5,10,t5 or 20 minute cycle times. The default cycle time is 10 minutes.

Static Made 260. On this setting the system does not alternate. The power unit automatically provides a different static pressure value according to the existing Comfort setting. This provides stable and mild internal pressure during this reduced function. If the green Indicator is on, this means that the Static Mode is activated Auto Firm (Nursing) 270. When caregivers are providing nursing care, the mattress is pressurised to be flat and firm to make nursing care easier. when the green indicator is on, this means that the Nursing Button is activated. However, after 30 minutes. the unit will resume its previous setting in order to protect the patient from the risk of developing pressure ulcers.

Auto Dual Mode 280. This enables a combination of pressure therapy.. The function enables Alternating and Static Modes to alternate on one hour cycles.

Low Pressure Alarm and Power Failure Alarm 290. The low pressure alarm is automatically activated when a low air pressure shortage is detected in the mattress operation and threatens the user's safety. The power failure alarm automatically occurs when there is a sudden power failure or the power cord is disconnected during normal operation of the system. The indicators do not turn on during normal operation. However, when the orange indicators are on, it means that either the Low Pressure Alarm or the Power Failure Alarm has occurred. The alarm can be muted by pressing this button. in order to restore the audible alarm function, you have to reset the power switch or press the ON/Stand By button.

Lock/Unlock button 300 is used to prevent the user from accidentally changing the control panel settings. The button can lock the existing settings status. Press again to unlock.

(However, the “On/Stand By’ button and “Nursing” button cannot be locked with this button.) if cardiac arrest occurs, the mattresses can be deflated in less than 10 seconds to altow cardiac resuscitation procedures to be performed by puliing a CPR tab 310 on the mattress to remove a plug from the gas supply pipe to allow air to rapidly exit the mattress. it will be appreciated that exemplary embodiments of the present invention may be particuiarly suitable for use as pressure relief mattresses.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification. and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or simiiar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (1)

1. Claims A mattress assembly comprising a mattress and a gas supply means wherein the mattress comprises a plurality of chambers which are adapted to be inflated with gas and wherein the gas supply means comprises a controller adapted to control the pressure of gas within said chambers and wherein said mattress assembly: (i) comprises only two pipes connecting the mattress to a pump; and/or (ii) is adapted to allow measurement of the pressure under the patient; and/or (iii) is adapted to provide the ability to adjust pressure around a pre-set value in both static and dynamic modes of operation; and/or (iv) is adapted to automatically reduce pressure when switching from a dynamic mode to a static mode and/or to automatically increase pressure when switching from a static mode to a dynamic mode; and/or (v) is adapted to self calibrate a measured pressure. A mattress assembly according to claim 1, wherein said mattress assembly is adapted to automatically reduce pressure when switching from a dynamic mode to a static mode and/or to automatically increase pressure when switching from a static mode to a dynamic mode and wherein if a user has varied the pressure from a pre-set pressure setting then the controller is adapted to take that into account when switching between the dynamic and static modes such that the pressure in the mode which is switched to will also be varied from the pre-set pressure in that mode. A mattress assembly according to any preceding claim, wherein the controller has predetermined modes of operation which can be activated by a user and the controller is adapted to allow user settings to be inputted in addition to predetermined settings. A mattress assembly according to any preceding claim, wherein the controller suitably has a nursing mode and in the nursing mode the controller may cause the chambers of the cells of the mattress to be inflated to a pressure of 40mmHg or more and wherein the controller is adapted to revert to the mode the mattress was previousiy in before the nursing mode was chosen after a given period of time. A mattress wherein the mattress comprises a plurality of cells which are adapted to be inflated with a gas and wherein a number of such cells each comprise a first chamber separated from a second chamber by a dividing wall and wherein each of said first and second chambers is adapted to be inflated with a gas.