EP2050425B1 - Alternative inflation method of a support device with inflatable cells and device for implementing the method - Google Patents

Description

The present invention relates to the field of pressure regulation for support devices with cells or inflatable compartments such as therapeutic mattresses. Such mattresses are used in particular to aliter patients suffering from or presenting risks of developing skin diseases such as pressure sores related to prolonged maintenance without movement while sitting or lying down.

The invention more particularly relates to a method of alternately inflating inflatable cells of such a support device and a particular device for the implementation of this method.

In an inflatable cell support device such as a therapeutic mattress, each inflatable cell communicates sealingly with at least one means for supplying a fluid inflating the cells, traditionally air, via at least one solenoid valve, which is itself connected to a control device controlling the inflation and the regulation of the fluid pressure inside the inflatable cells of the mattress.

In practice, to fill / inflate the inflatable cells of the support device, air is sent into the cells until the necessary pressure is reached. Conversely, to empty or deflate the inflatable cells or to adjust the inflation pressure, air is evacuated through a discharge orifice provided for this purpose, and preferably also provided with a solenoid valve also controlled by the device. controlling the inflation.

Supporting devices of this type are used as mattresses for patient care because they provide adequate body position and support on the surface of the mattress, depending on the morphology and position of the patients.

In principle, the ideal comfort of a patient, and the optimal vascularization of the tissues, in particular to avoid the formation of pressure ulcers or to reduce localized pains in certain zones of support of the body on the mattress, are obtained when the points of support of the body are redistributed on the surface of the mattress, that is to say when the pressure exerted by the different areas of the body on the mattress (called "interface pressure") is substantially identical for all the points of the surface of the mattress. body in contact with the mattress and if, on the other hand, this contact surface of the body with the mattress is as high as possible. This requires adapting the inflation of the inflatable cells of the mattress under the different parts of the body to control the level of depression of the body in the different areas of the mattress.

To do this, a distribution of the air pressure inside the inflatable cells is carried out by controlling their filling / emptying as a function, in particular, of the measurements of stress exerted by the patient's body on the mattress, these measurements being carried out with sensors in, on or preferably below the mattress depending on the type of sensors used. These sensors, hereinafter referred to as morphology sensors, are known to those skilled in the art and measure, in particular, a constraint consisting of the pressure exerted by the patient's body on the cells of the mattress called interface pressure or the distance of embedding or immersion volume of the patient's body in the cells of the mattress, as described for example in the European patent EP 0 676 158 and the European patent EP 1 056 372 in the name of the plaintiff. From these measurements, it is calculated that a regulation pressure of the inflation of the cells appropriate according to the morphology of the patient on the mattress. The term "morphology of the patient on the mattress" is here understood to mean both the mass of the patient and his area of contact with the mattress, that is to say his position on the mattress.

The control and regulation of the filling / emptying of the inflatable cells also makes it possible to provide support devices operating in "alternating" inflation mode cells in which alternately inflate and deflate alternately and simultaneously some cells of the support device evenly distributed in the length thereof. For example, one cell out of two is deflated / inflated and the cells adjacent to those previously deflated and then inflated are deflated / inflated.

Thus, each inflatable cell of the support device is successively and gradually deflated / re-inflated, creating a kind of wave moving in the longitudinal direction of the support device back and forth and discharging the interface pressure locally favoring this. place the vasculature of the soft tissues at the interface with the surface of the support device.

In order to perform such an alternating mode of inflating the cells, the current inflatable cell support devices comprise control and regulation systems for the inflation pressure incorporating complex electronic circuits for controlling the solenoid valves and other inflation compressors, circuits comprising between others digital counters and clocks whose cost of development and realization is particularly high, as well as congestion. In addition, with the control and regulation systems known to date, the inflation cycle and alternate deflation cycle times are fixed, left to the discretion of the manufacturer or user.

More particularly, the present invention relates to a method of alternately inflating inflatable cells of a support device of a mattress type supporting member for supporting the body of a patient, said mattress comprising inflatable cells of a fluid, in particular air, comprising at least one zone comprising two first and second series of inflatable cells, said first and second cells respectively, the cells of each series communicating hydraulically or preferably pneumatically, with each other, and with inflation means, the cells of each series of cells that can be either in open communication with the pump and the cells of the other series of cells, or in closed communication with the pump and the cells of the other series and open communication with the outside a so-called venting state, in which deflation and alternating re-inflation cycles are performed in which each said series of cells is deflated and then re-inflated alternately and successively, said first cells being deflated and then re-inflated simultaneously with re-inflation and then respectively deflation of said second cells, the steps of deflation and reinflation alternate said first and second cells of the support device comprising at least one step of inflation of said cells to a value of at least a reference pressure PC, PRmax, PRmin whose value is determined from a continuous measurement carried out using a sensor, referred to as a morphology sensor, measuring the stress generated by the patient's body on the cells.

In patents EP-1 695 681 and EP-0 168 213 alternate inflation / deflation methods are described. But in these two patents, the regulating pressure at which the cells must be inflated, is not determined by means of a sensor directly measuring the stress exerted by the patient's body on the mattress, but it is deduced pressure measurements inside the cells, which is less reliable and less easy to implement.

More precisely, in the document EP 1 695 681 a predetermined alternating cycle time is set and the inflation pressure is determined as a function of a residual pressure value of the air measured inside the cells at the end of deflation during the cycle, after a given fixed time predetermined. So in EP 1 695 681 the inflation pressure of the cells can be varied regularly during the cycle depending on the morphology of the patient, but the duration of the inflation / deflation cycles can not be varied automatically according to the morphology of the patient.

Finally, in EP 1 695 681 the cells are not deflated completely at the end of deflation, which is disadvantageous in terms of vascularization efficiency.

In EP 0168 213 the regulation pressure or inflation pressure of the cells is determined from pressure measurements inside the cells when the pressure in the different cells equilibrates during a calibration or initialization step before starting the alternating cycle well said. And, this calibration step must be repeated at regular intervals. In EP 0168231 no details are provided as to the embodiment of the alternate inflation / deflation method subsequent to this initial calibration step.

So in EP 1 695 681 and EP 01680213 , the reference pressures at which the cells must be inflated during an inflation / deflation cycle are determined as a function of the air pressure inside the cells measured at regular intervals, which further requires the implementation of a clock.

The object of the invention is therefore to provide a method of alternately inflating inflatable cells of a support device such as a therapeutic mattress and a device for its implementation which are more economical than the methods and devices. known.

Another object of the present invention is to provide a method of alternately inflating therapeutic mattress cells whose inflation / deflation cycle time is a function of the morphology and the position of the patient on the mattress.

This object is achieved according to the invention by a method of alternately inflating inflatable cells of a support device of a mattress-type supporting element for supporting the body of a patient, said mattress comprising inflatable cells of a fluid. , in particular comprising at least one zone comprising two first and second series of inflatable cells, said first and second cells respectively, the cells of each series communicating hydraulically or preferably pneumatically, with each other, and with inflation means comprising a pump, the cells of each series of cells can be either in open communication with the pump and the cells of the other said series of cells, or in closed communication with the pump and the cells of the other series and open communication with the external, so-called venting state, in which process deflation cycles and alternating re-inflation in which each said series of cells is deflated and then inflates alternately and successively, said first cells being deflated and then re-inflated simultaneously with reinflation then respectively deflation of said second cells, the steps s of alternating deflation and reinflation of said first and second cells of the support device comprising at least one step of inflating said cells to a value of at least a reference pressure PC, PRmax, PRmin whose value is determined from continuous measurement carried out by means of a sensor, called a morphology sensor, measuring the stress generated by the patient 's body on the cells, characterized in that the steps of alternating deflation and re - inflation of said first and second cells are involved in a cycle controlled by the start or stop of said inflation means, which start or stop of said inflation means are controlled according to the value of the pressure of the fluid measured inside said cells and its comparison to one said a reference pressure value, and the start or stop of said inflation means control the settings open communication state or closed communication state of said first or second cells with said inflation means.

The method according to the invention therefore involves the implementation of two measurements and their comparison, namely the continuous measurement of the internal pressure of the cells during the cycle and its comparison with a reference pressure calculated from the continuous measurements made by a morphology sensor.

Thus, it is possible to control the cycle without using a clock to control the starting or stopping of the inflation means and the setting in open or closed communication state of the cells with the inflation means.

In addition, according to the present invention, the cycle time is automatically adjusted continuously according to the said reference pressure value measured with the aid of the said morphology sensor, and thus according to the morphology of the patient on the mattress.

Finally, the next stage of the cycle can only be carried out if the inflation means have succeeded, during inflation, in restoring the pressure in the cells to a said reference pressure value. This is a safety because the cycle is necessarily interrupted in case of leakage unlike previous methods in which clocks controlled the triggers of the successive stages of the cycle even in case of leakage.

• les mises en marche ou arrêt desdits moyens de gonflage sont commandées en fonction de la valeur de la pression du fluide mesurée dans lesdites cellules et sa comparaison à une valeur d'une première pression de référence, appelée pression de régulation, déterminée en fonction de la morphologie du patient, et une valeur d'une deuxième pression de référence appelée pression de consigne, ladite pression de consigne étant supérieure à ladite pression de régulation et calculée par rapport à la pression de régulation, et
• les mises en marche ou arrêt desdits moyens de gonflage commandent le choix de la dite première ou dite deuxième pression de référence à prendre en compte pour ladite comparaison dans la mise en marche ou arrêt suivante des moyens de gonflage au cours d'un dit cycle.

More particularly, in the process according to the invention:

• the starting or stopping of said inflating means is controlled as a function of the value of the pressure of the fluid measured in said cells and its comparison with a value of a first reference pressure, called the regulating pressure, determined according to the morphology of the patient, and a value of a second reference pressure called setpoint pressure, said setpoint pressure being greater than said control pressure and calculated with respect to the regulating pressure, and
• switching on or off said inflation means controls the choice of said first or second said reference pressure to be taken into account for said comparison in the next start or stop of the inflation means during a said cycle.

• lesdites premières cellules sont connectées les unes à la suite des autres en série et,
• lesdites deuxièmes cellules sont connectées les unes aux autres en série, et
• on réalise les étapes successives suivantes dans lesquelles :
  1. a) lorsque (t2) toutes les cellules des deux dites première et deuxième série sont gonflées à une pression correspondant à une pression dite de régulation Pr, la pompe étant à l'arrêt, les cellules de chaque série de cellules étant en état de communication ouverte avec la pompe et les cellules de l'autre dite série de cellules, la détection de ladite pression de régulation dans lesdites premières et deuxièmes cellules, commande :
     1. a-1) le dégonflage des dites premières cellules par mise à l'air libre des dites premières cellules, et
     2. a-2) le surgonflage des dites deuxièmes cellules par mise en marche de la pompe jusqu'à une pression déterminée dite pression de consigne Pc supérieure à la pression de régulation, et
  2. b) lorsque (t3) la pression de consigne est atteinte dans lesdites deuxièmes cellules, la détection de ladite pression de consigne dans lesdites deuxième cellules commande l'arrêt de la pompe et la mise en état de communication ouverte avec la pompe et les cellules de l'autre dite série de cellules pour les deux séries de cellules, ce qui permet un transfert du fluide des dites deuxièmes cellules vers lesdites premières cellules et donc le dégonflage des dites deuxièmes cellules et regonflage simultanée des dites premières cellules jusqu'à une dite pression de régulation, et
  3. c) lorsque (t5) toutes lesdites premières et deuxièmes cellules sont à une pression correspondant à une pression dite de régulation, la détection d'une dite pression de régulation dans lesdites cellules commande l'arrêt de la pompe, lequel arrêt de pompe commande :
     1. c-1) le dégonflage des dites deuxièmes cellules par mise à l'air libre des dites deuxièmes cellules, et
     2. c-2) le surgonflage desdites premières cellules par mise en marche de la pompe jusqu'à une dite pression de consigne Pc et
  4. d) lorsque (t6) ladite pression de consigne est atteinte dans lesdites premières cellules, la détection de ladite pression de consigne dans lesdites premières cellules commande l'arrêt de la pompe et la mise en état de communication ouverte avec la pompe et les cellules de l'autre dite série de cellules pour les deux séries de cellules, ce qui permet un transfert du fluide des premières cellules vers les deuxièmes cellules et donc le dégonflage des dites premières cellules et gonflage simultanée des dites deuxièmes cellules, jusqu'à une dite pression de régulation, et
  5. e) le cas échéant on réitère le cycle des étapes a) à d).

More particularly still, in the process according to the invention:

• said first cells are connected one after the other in series and,
• said second cells are connected to each other in series, and
• the following successive steps are carried out in which:
  1. a) when (t2) all the cells of the two said first and second series are inflated to a pressure corresponding to a so-called control pressure Pr, the pump being stopped, the cells of each series of cells being in communication state open with the pump and the cells of the other said series of cells, the detection of said regulation pressure in said first and second cells, control:
     1. a-1) the deflation of said first cells by venting said first cells, and
     2. a-2) the over inflation of said second cells by starting up the pump to a determined pressure, said set pressure Pc greater than the regulation pressure, and
  2. b) when (t3) the set pressure is reached in said second cells, the detection of said set pressure in said second cells controls the stopping of the pump and the open communication state with the pump and the cells of the other said series of cells for the two series of cells, which allows a transfer of the fluid of said second cells to said first cells and thus the deflation of said second cells and simultaneous reinflation of said first cells to a said regulation pressure, and
  3. c) when (t5) all said first and second cells are at a pressure corresponding to a so-called control pressure, the detection of a said control pressure in said cells controls the stopping of the pump, which pump stop commands:
     1. c-1) the deflation of said second cells by venting said second cells, and
     2. c-2) the over inflation of said first cells by switching on the pump to a said set pressure Pc and
  4. d) when (t6) said set pressure is reached in said first cells, the detection of said set pressure in said first cells controls the stopping of the pump and the open communication state with the pump and the cells of the the other said series of cells for the two series of cells, which allows a transfer of the fluid from the first cells to the second cells and thus the deflation of said first cells and simultaneous inflation of said second cells, to a said pressure regulation, and
  5. e) where appropriate, the cycle of steps a) to d) is repeated.

In steps a-1) and c-1) the deflation of said first and second cells corresponds to a partial emptying of said cells. In practice, only 15 to 20% of the fluid contained in said cells is transferred. However, given the support exerted in the body of the patient, the cells that deflate by escaping, deflate faster than cells during inflation. This makes it possible to reach a zero relative pressure with respect to the atmospheric pressure during deflation.

The duration of the so-called balancing phases of steps b) and d) and the over-inflation / deflation phase of steps a) and c) is determined by the time taken by the inflation means to reach the regulation or set-point pressures determined by the mass of the element to be supported resting the support device.

The method of the invention is advantageously distinguished from the state of the art by its variable cycle time which is adjusted automatically according to the morphology of the patient. It is therefore more efficient than known inflation control methods and devices because it allows an automatic parameterization of the additional therapeutic variable that constitutes the cycle time.

Indeed, the inflation time varies depending on the patient. Thus for a relatively light patient, the volume of immersion of the body in the mattress is relatively low and the cells will be more quickly inflated.

This characteristic of continuous self-regulation of the cycle time according to the weight of the patient according to the method according to the invention is very advantageous, since the patients of small corpulence present risks of pressure sores more important and require a massage faster than for patients of greater body build.

The method according to the invention is also more economical than known methods because it does not require the implementation of expensive electronic clock to sequence the successive phases of stopping and starting of the pump.

More particularly, the support device is a mattress comprising a plurality of air-filled cells, in the form of tubes arranged transversely to the longitudinal direction of the mattress, and the inflation means comprise a pump comprising an air compressor.

Finally, its implementation is secure because it depends on the ability of the therapeutic mattress to properly wear the patient lying on the mattress. Indeed, the duration of the deflation / reinflation phase of steps a) and c) can vary according to the integrity of the cells of the support device, up to the blocking of the cycle and generating a malfunction alarm, if a fluid leakage inflation in the cells or hydraulic connection means between the cells and the inflation means is greater than the maximum flow of the inflation device. In this case the stop of the inflation system is never done, so the cycle does not go to the next phase.

In case of leakage therefore, the method according to the invention is interrupted, but the inflation of the cells in continuous leakage so that there is no risk of sudden deflation which could be dangerous for the patient.

According to a preferred characteristic of the process of the invention, the so-called "reference" fluid pressure is determined with respect to the regulation pressure, in particular proportional to the regulation pressure, preferably greater than the "regulation" pressure and more preferably at least 10% higher than the "control" pressure, more preferably at least 15% to 30% higher than the "control" pressure.

• lesdites premières cellules sont reliées à au moins une première électrovanne permettant soit la communication ouverte avec la pompe et lesdites deuxièmes cellules dans un état de l'électrovanne dit de repos, soit la mise à l'air libre des dites premières cellules par mise en état de communication fermée avec la pompe et lesdites deuxièmes cellules et communication ouverte avec l'extérieur, en état de l'électrovanne dit d'activation,
• lesdites deuxièmes cellules reliées à au moins une deuxième électrovanne permettant soit la communication ouverte avec la pompe et lesdites premières cellules dans un état de l'électrovanne dit de repos, soit la mise à l'air libre des dites deuxièmes cellules par mise en état de communication fermée avec la pompe et lesdites premières cellules et communication ouverte avec l'extérieur, en état de l'électrovanne dit d'activation, et
• les arrêts de la pompe déclenchent les mises en états d'activation ou de repos des dites premières et deuxièmes électrovannes.

According to a preferred embodiment of the method according to the invention:

• said first cells are connected to at least one first solenoid valve allowing either the open communication with the pump and said second cells in a state of the so-called resting solenoid valve, or the venting of said first cells by readiness communication closed with the pump and said second cells and open communication with the outside, in the so-called activation solenoid valve state,
• said second cells connected to at least one second solenoid valve allowing either the open communication with the pump and said first cells in a state of the so-called resting solenoid valve, or the venting of said second cells by conditioning them closed communication with the pump and said first cells and open communication with the outside, in the so-called activation solenoid valve state, and
• the stops of the pump trigger activation or rest states of said first and second solenoid valves.

• aux étapes a) et c), l'arrêt de la pompe commande la mise en état d'activation de ladite première électrovanne et respectivement dite deuxième électrovanne, et
• aux étapes b) et d), l'arrêt de la pompe commande la mise en état de repos de desdites deuxièmes et premières électrovannes.

More particularly, the stops of the pump trigger the following states:

• in steps a) and c), stopping the pump controls the activation of said first solenoid valve and said second solenoid valve respectively, and
• in steps b) and d), stopping the pump controls the rest state of said second and first solenoid valves.

In fact said solenoid valves are 3-way solenoid valves, preferably 3/2 solenoid valves in line

This embodiment requires the implementation of three-way solenoid valve (called solenoid valves "3/2 solenoid valves").

• un premier canal interne apte à coopérer avec un orifice ouvert d'alimentation et d'évacuation d'air d'une dite cellule,
• un deuxième canal interne apte à communiquer avec un tuyau d'alimentation de l'électrovanne et dite cellule en fluide, et
• un troisième canal interne débouchant à l'air libre, permettant l'évacuation du fluide de ladite cellule, ledit deuxième canal étant obturé.

These three-way solenoid valves include:

• a first internal channel adapted to cooperate with an open port for supplying and discharging air from a said cell,
• a second internal channel adapted to communicate with a supply pipe of the solenoid valve and said cell in fluid, and
• a third internal channel opening to the air, allowing the evacuation of the fluid from said cell, said second channel being closed.

Preferably, said solenoid valves comprise two said first and second endpieces arranged symmetrically with respect to a main body defining an outer surface of rounded shape, preferably said main body being of cylindrical shape, said main body being of the same longitudinal axis as said first and second tips.

More preferably, the outer diameter of said cylindrical body is substantially the same or slightly greater than that of said supply pipe. Thus, the solenoid valve can be arranged in the extension of the pipe in an optimal size.

In a preferred embodiment, the control pressure corresponds to a pressure within a pressure range known as the control range Prmax to Prmin. This makes it possible to avoid excessive sensitivity which could trigger undesirable disturbances of cycles, in particular variations in cycle time, for the same patient, since the regulation pressure can vary according to his movements on the mattress, among others. In this case the set pressure is higher than Prmax.

• aux étapes b) et d), lors dudit transfert, lorsque l'on détecte la pression maximale de régulation (Prmax) dans lesdites deuxièmes et respectivement premières cellules alors que la pression minimale de régulation Prmin n'est pas atteinte dans lesdites lesdites premières et respectivement deuxièmes cellules, la mise en marche de la pompe est déclenchée pour le gonflage des dites premières et deuxièmes cellules, et
• aux étapes a) et c), l'arrêt de pompe est déclenchée par la détection d'une pression dans lesdites premières et deuxièmes cellules comprise dans ladite plage de régulation, et le redémarrage de la pompe aux étapes a-2) et c-2) est déclenché par la détection d'une pression dans lesdites deuxièmes et respectivement premières cellules inférieure à ladite pression de consigne.

According to an advantageous characteristic of the process according to the invention:

• in steps b) and d), during said transfer, when the maximum regulation pressure (Prmax) is detected in said second and respectively first cells while the minimum regulation pressure Prmin is not reached in said first and first cells, respectively second cells, the start of the pump is triggered for the inflation of said first and second cells, and
• in steps a) and c), the pump stop is triggered by detecting a pressure in said first and second cells within said control range, and restarting the pump in steps a-2) and c- 2) is triggered by the detection of a pressure in said second and respectively first cells less than said set pressure.

It will be understood that in some cases, in steps b) and d), the flow rate of the fluid transferred between the two series of cells is insufficient to allow the minimum value of the regulation pressure range to be reached in said cells and or maintain the pressure in said first and second cells connected to each other in said regulation range, because, in view of the pressure exerted by the patient's body on the deflated cells, the deflating cells deflate faster than those that are being reinflated are not inflated. Starting the pump slows the deflation of the cells being deflated and allows the cells being re-inflated to reach the control pressure.

Advantageously, said mattress comprises at least one zone in which said two series of cells comprise the same number of cells in each series, with one cell of each of said two series of cells alternately in the longitudinal direction of the mattress-type device in said area. In other words, one cell of each of said two sets of cells is adjacent to one cell of the other set of cells, i.e., preceded and / or followed by one cell of the other set of cells.

It is therefore understood that during each cycle of deflation and reinflation, deflates and deflates respectively one cell on two of the support device alternately.

Advantageously, the mattress comprises at least a third series of cells, called third cells in communication with said pump and said first and second cells, of preferably said third cells hydraulically communicating with each other continuously, and said third cells are interposed hydraulically between the pump and said first and second cells, so that the pressure in said third cells varies between the control pressure and the set pressure during the steps a) to d).

More particularly, said third cells are interposed upstream of said first and second solenoid valves.

According to the invention, it is possible to implement a pump of relatively lower flow rate and therefore less expensive compared to pumps controlled by a clock according to the prior art because the pumps were calibrated as a function of the commissioning time; ie the initial inflation time of the mattress, whereas according to the invention the pump is calibrated solely according to the volume of the cells of each said first and second series to be reinflated from P = 0 to Pc, which is less than half of the total volume.

More particularly, the flow rate of the pump is chosen according to the volume of said first and second cells to obtain a cycle time of 5 to 20 minutes for patients of 50 to 120 kg.

The implementation of these third cells makes it possible to constitute a reserve of fluid which completes the volume of fluid transferred to steps b) and d), which makes it possible to implement a pump of smaller flow rate.

Advantageously, the number of said first and second cells is less than half the total number of cells in the mattress, preferably between 1/3 and 1/2 of the total number of cells.

Preferably, said area of the first and second cells covers the sacrum area, and the mattress comprises third cells at the foot area and the head area. More particularly still, said first and second cells are number of 4 each, 8 in total, in said zone, and the mattress comprises 20 cells, 3 in foot zone, and 7 in the head zone.

• desdits moyens de gonflage,
• des tuyaux de communication hydraulique reliant lesdits moyens de gonflage aux dites cellules gonflables,
• un dit capteur de morphologie apte à mesurer directement la contrainte exercée par un dit patient sur lesdites cellules gonflables du dispositif de support, et déterminer ladite valeur de pression de référence, et
• desdits moyens de mesure de la pression à l'intérieur desdites cellules gonflables, et
• desdits moyens de commande desdits moyens de gonflage
• lesdits moyens de commande desdits moyens de gonflage étant connectés aux dits moyens de mesure de pression et au dit capteur de morphologie, et étant aptes à commander les mises en marche et arrêts desdits moyens de gonflage en fonction de la valeur de la pression du fluide mesurée dans lesdites cellules par lesdits moyens de mesure de la pression en la comparant à au moins une dite valeur de pression de référence déterminée à l'aide dudit capteur de morphologie.

The present invention also proposes a device for inflating a said support device for a patient to support, in particular a mattress or a cushion for supporting the body of a patient, comprising said inflatable cells of a fluid. , in particular air, allowing the implementation of an inflation method according to the invention, the inflation device comprising:

• said inflation means,
• hydraulic communication pipes connecting said inflating means to said inflatable cells,
• a said morphology sensor able to directly measure the stress exerted by a said patient on the said inflatable cells of the support device, and to determine the said reference pressure value, and
• said means for measuring the pressure inside said inflatable cells, and
• said means for controlling said inflation means
• said control means of said inflating means being connected to said pressure measuring means and said morphology sensor, and being able to control the starting and stopping of said inflation means as a function of the value of the measured fluid pressure in said cells by said pressure measuring means by comparing it with at least one said reference pressure value determined with the aid of said morphology sensor.

Preferably, the device according to the invention comprises a morphology sensor able to measure the pressure applied by a said patient to said inflatable cells of the support device, and to determine said regulation pressure value and said setpoint pressure value, said sensor being connected to said control means of the inflation means.

Preferably, the morphology sensor makes it possible to determine and quantify the interface pressure exerted by the patient on the cells resulting from the mass of the element to be supported by the cells of a support device, which causes a displacement of fluid and a depression of the element to be supported in the cells causing an increase in the fluid pressure in the cells. Morphology sensor devices are known to those skilled in the art as mentioned above, but preferably said morphology sensor has at least one resistive force sensing cell.

The means for measuring the pressure inside the cells may be, for example, piezoelectric sensors.

• desdites première et deuxième électrovannes reliées à des dites premières et respectivement deuxièmes cellules et dits moyens de gonflage, lesdites électrovannes étant aptes à permettre soit la communication ouverte avec la pompe et lesdites deuxièmes et respectivement premières cellules dans un état de l'électrovanne dit de repos, soit la mise à l'air libre des dites premières et respectivement deuxièmes cellules par mise en état de communication fermée avec la pompe et lesdites deuxièmes et respectivement premières cellules et communication ouverte avec l'extérieur, en état de l'électrovanne dit d'activation, et
• des moyens de détection d'arrêt de pompe connecté à un séquenceur apte à déclencher des commandes successives d'états d'activation ou de repos desdites électrovannes et apte à faire le choix des dites pressions de référence selon une séquence déterminée.

More particularly, the device according to the invention comprises:

• said first and second solenoid valves connected to said first and second cells respectively and said inflating means, said solenoid valves being able to allow either open communication with the pump and said second and respectively first cells in a state of the so-called solenoid valve , ie the venting of said first and second cells by placing in closed communication state with the pump and said second and respectively first cells and open communication with the outside, in the state of the so-called solenoid valve. activation, and
• pump stop detection means connected to a sequencer capable of triggering successive commands of activation or rest states of said solenoid valves and able to make the choice of said reference pressures in a specific sequence.

According to another characteristic of the inflation device of the invention, said inflation means comprise a low voltage pump powered at a voltage of 12 volts AC.

Preferably, the inflation device of the invention also comprises a 12-volt DC supply comprising a bridge of transistors, in order to generate the AC voltage of said inflation means. Furthermore, the inflation device also comprises a morphology sensor, able to measure the stress applied by a said element to be supported on the said inflatable cells of the support device and a pressure sensor able to measure the pressure inside the inflatable cells. .

Still according to the invention, the power supply of the inflation device of the invention finally comprises a power supply battery able to maintain the operation of the inflation device in the event of a power failure.

• les figures 1A et 1B représentent un dispositif de support à cellules gonflable incorporant un dispositif de gonflage alterné pour la mise en oeuvre du procédé de gonflage alterné de l'invention ;
• la figure 2 représente schématiquement la structure électrique d'un dispositif de gonflage alterné conforme à la présente invention,
• la figure 3 représente des courbes de variations de pressions dans un dispositif de support gonflable fonctionnant suivant le procédé de gonflage alterné de l'invention,
• la figure 4 représente des courbes de variations de pressions dans un dispositif de support gonflable fonctionnant suivant le procédé de l'invention, pour un individu de 125 kg et une inclinaison nulle du dispositif de support,
• la figure 5 représente des courbes de variations de pressions dans un dispositif de support gonflable fonctionnant suivant le procédé de l'invention, pour un individu de 125 kg et une inclinaison de 60° entre deux zones du dispositif de support.
• la figure 6 représente des courbes de variations de pressions dans un dispositif de support gonflable fonctionnant suivant le procédé de l'invention, pour un individu de 45 kg et une inclinaison de 60° entre deux zones du dispositif de support,
• la figure 7 représente des courbes de variations de pressions dans un dispositif de support gonflable fonctionnant suivant le procédé de l'invention, pour un individu de 45 kg et une inclinaison nulle du dispositif de support.

Other advantageous features of the method and of the inflation device of the present invention will emerge more clearly on reading the detailed description which follows, which is carried out by way of illustration and not limitation of the scope of the invention with reference to the appended figures in which:

• the Figures 1A and 1B represent an inflatable cell support device incorporating an alternate inflation device for carrying out the alternate inflation method of the invention;
• the figure 2 schematically represents the electrical structure of an alternating inflation device according to the present invention,
• the figure 3 represents pressure variation curves in an inflatable support device operating according to the alternate inflation method of the invention,
• the figure 4 represents pressure variation curves in an inflatable support device operating according to the method of the invention, for an individual of 125 kg and a zero inclination of the support device,
• the figure 5 represents pressure variation curves in an inflatable support device operating according to the method of the invention, for a 125 kg individual and a 60 ° inclination between two areas of the support device.
• the figure 6 represents curves of pressure variations in an inflatable support device operating according to the method of the invention, for a 45 kg individual and a 60 ° inclination between two zones of the support device,
• the figure 7 represents pressure variation curves in an inflatable support device operating according to the method of the invention, for an individual of 45 kg and a zero inclination of the support device.

In the curves of Figures 3 to 7 the ordinate pressures are in inch H2O (1 inch H2O = 254 Pa = 2.19 mmHg) and the time on the abscissa is in seconds.

On the Figures 1A and 1B , there is shown a therapeutic mattress 11, equipped with an inflation device 1 according to the invention.

The therapeutic mattress 11 consists of 19 inflatable cells, said cells 12 being arranged transversely to the longitudinal direction of the mattress. Each cell consists of two compartments, respectively an upper compartment and a lower compartment, said upper and lower compartments, in the form of a coil, communicating with each other at their ends.

• une zone de pied 11P, constituée des 3 premières cellules (cellules n°1 à 3),
• Une zone médiane 11C, comportant 8 cellules (cellules n°4 à 11), et
• une zone de tête 11T, comportant également 8 cellules (cellules n°12 à 19).

The mattress 11 shown on the Figures 1A and 1B , has the following three areas:

• a foot zone 11P consisting of the first 3 cells (cells 1 to 3),
• A median zone 11C, comprising 8 cells (cells 4 to 11), and
• a head zone 11T, also comprising 8 cells (cells No. 12 to 19).

The central zone 11C corresponds to an inflated zone according to an alternating inflation method of the present invention.

The central zone 11C comprises a first series of cells, called first 12C1 cells (cells 5, 7, 9 and 11), and a second series of cells, called second 12C2 cells (cells 4, 6, 8 and 10). ).

The cells of each of said first and second series 12C1 and 12C2, are connected in series, that is to say in line, the two series being connected in parallel, fed by the same inflation device 1.

More specifically, the cells 12 of the mattress 11 each comprise an inlet orifice and an outlet orifice (not shown). The inlet or supply port is located at one end of the upper compartment, in the transverse direction of the mattress, the outlet or outlet being located at the end of the same side of the lower compartment, in the transverse direction of the mattress (or longitudinal direction of the cell). Two adjacent cells have their orifices disposed at opposite ends in the transverse direction of the mattress and belong to a different series of cells.

So, on the Figure 1A it can be seen that the cell No. 1 at the foot of the mattress is fed by a pipe 13 at the end of the upper compartment of the cell No. 1, and the end of the same side the lower compartment of the cell No. 1 communicates directly with the end of the lower compartment on the same side of the cell No. 3, the end of which on the same side of the upper compartment communicates, from a branch tee connection , 13a, with, on the one hand, a first solenoid valve 14 ₁ , from which are placed in series cells 5, 7, 9 and 11 of said first series 12C1 of cells, and, on the other hand, parallel to the cells 12C1, the end of the same side of the upper compartment of the cell No. 13, which is the second cell of the head zone 11T from the foot of the bed, the other cells of the head zone, 15, 17 and 19, being mounted one after the other, in series.

• d'une part, la deuxième électrovanne 14₂, à partir de laquelle la cellule n°4 du matelas, représentant la première cellule de ladite deuxième série de cellules 12C2, est alimentée, les autres cellules de la deuxième série de cellules 12C2, à savoir les cellules n°6, 8 et 10, étant alimentées en série, c'est-à-dire communiquant en série entre elles symétriquement et parallèle à ladite première série de cellules 12C1, et
• d'autre part, un tuyau 13 alimente l'extrémité du compartiment supérieur du premier compartiment n°12 de la zone de pied, l'extrémité du même coté du compartiment inférieur de la deuxième cellule suivante de la zone de tête, à savoir la cellule n°14 à partir du pied du lit, étant alimentée à partir de l'extrémité du même coté du compartiment inférieur de la cellule n°12 et, ainsi de suite, en série sur la cellule n°16 puis l'avant-dernière cellule n°18 de la zone de tête 11T.

Symmetrically, on the Figure 1B it is shown that the cell n ° 2 of the foot zone 11P is fed, at the opposite end of the upper compartment, from the device 1, by the same pipe 13. And, the end of the same side of the lower compartment of the cell n ° 2 of the foot zone 11P feeds a T branching connection 13a, from which is fed in parallel:

• on the one hand, the second solenoid valve 14 ₂ , from which the cell No. 4 of the mattress, representing the first cell of said second series of cells 12C2, is powered, the other cells of the second series of cells 12C2, namely cells 6, 8 and 10, being fed in series, that is to say, communicating in series between them symmetrically and parallel to said first series of cells 12C1, and
• on the other hand, a pipe 13 feeds the end of the upper compartment of the first compartment 12 of the foot zone, the end of the same side of the lower compartment of the second following cell of the head zone, namely the cell No. 14 from the foot of the bed, being fed from the end of the same side of the lower compartment of the cell No. 12 and, so on, in series on the cell No. 16 and the front- last cell No. 18 of the head zone 11T.

It can thus be seen that the cells of the head zone 11T and of the foot zone 11P constitute third cells, which are situated upstream of the first and second solenoid valves 14 ₁ and 14 ₂ .

The solenoid valves 14 ₁ and 14 ₂ have been shown disposed in line between the pipes 13 and the orifices of the first cells of said first series 12C1 and second series of cells 12C2. However, they could be arranged in a specific housing.

Said first and second solenoid valves 14 ₁ and 14 ₂ are 3-way solenoid valves of the 3/2 type, as previously described. On the solenoid valves 14 ₁ and 14 ₂ , there is shown the lateral vents of venting 14a. Their change of readiness between their said activation state and said resting state is controlled by the transistors ₁ and 6, respectively, the sequencer 62 6 described below.

When a solenoid valve is in the activated state, only the lateral vent port is open. When a solenoid valve is in the so-called rest state, the lateral orifice for venting is closed and the two other orifices are open, communicating, respectively, with the pump and the first cell of the series of cells concerned by said solenoid valve.

More particularly, said solenoid valves comprise a main body comprising a cylindrical internal cavity into which both said first and second internal channels open, said internal cavity enclosing a longitudinal magnetic core capable of being displaced in said axial longitudinal direction of said solenoid valve, said magnetic core moving within an axially extending induction coil, said core being movable between, on the one hand, an open position in which the core is disengaged from the ends of said first and second inner channels opening in said internal cavity so as to allow the fluid to pass through said solenoid valve between the ends of said two said first and second ends and, on the other hand, a closed position wherein said core obstructs the end opening into said internal cavity of one of said two said first and second internal channels of the solenoid valve so as to prevent the flow of fluid through said solenoid valve between the ends of said two first and second end.

This type of solenoid valve is called "compact in-line solenoid valve" because the various components are arranged along the same axis as the longitudinal axis of the solenoid valve.

On the other hand, the passage of the fluid through the solenoid valve between its first and second ends is always axially along the same longitudinal axis as that of the solenoid valve, unlike the conventional 3-way solenoid valves in which the axis of the core and the displacement of the core are generally perpendicular to a conduit for the passage of fluid inside the solenoid valve.

"Compact online" solenoid valves of this type are described in the French patent application FR 0701391 in the name of the plaintiff.

This organization of the different cells 12 of the mattress, in two series of cells 12C1 and 12C2, mounted in parallel but arranged so that the cells of said first series 12C1 and second series 12C2 succeed each other alternately, and with the two series controlled by a different solenoid valve, facilitates the implementation of the alternate inflation method according to the invention, with a minimum size around the pipe network mattress and other hydraulic communication means between the cells.

On the figure 3 pressure curves as a function of time are shown in the cells 12C1 and 12C2 during the various phases of the alternating inflation cycles of the cells 12C1 and 12C2 described below.

Before t0, said first cells 12C1 are in the reinflation phase, said first solenoid valve 14 ₁ being in said rest state, allowing the supply of said cells 12C1 via the pipe 13 from the inflation device 1. Simultaneously, at reinflation of the first 12C1 cells, the second 12C2 cells are in the deflation phase and, as shown in FIG. figure 3 they have reached zero relative pressure. In this phase before t0, the second solenoid valve 14 ₂ is in the activation state.

At t0, the pressure detected inside the first cells 12C1 reaches the set pressure Pc determined to be approximately 20% higher than the upper limit PRmax of the regulation range. This detection of a pressure Pc in said cells 12C1 causes the pump to stop. And, stopping the pump triggers the next phase (phase P.1) in which the second solenoid valve 14 ₂ is put in a state of rest. Thus, from t0, in phase P.1, the two first and second solenoid valves 14 ₁ and 14 ₂ are in a state of rest, the pump is stopped. And, phase P.1 is a phase of air transfer balancing of said first 12C1 cells to the second 12C2 cells during which the pressure in 12C1 cells decreases and the pressure in 12C2 cells increases by simple transfer of air under the effect of the support of the patient.

At t1, the pressure measuring means 3 in the cells measure a pressure in the first cells 12C1 equal to the upper limit PRmax of the regulation range, while, simultaneously, the pressure in the second cells 12C2 is below the limit. lower PRmin of the control range. These pressure conditions in said first and second cells 12C1 and 12C2 trigger the restart of the pump without there being a change of position of the first and second solenoid valves 14 ₁ and 14 ₂ .

At t2, the pressure in said second cells 12C2 reaches the lower limit PRmin and the first and second cells 12C1 and 12C2 are maintained at a pressure within the range of regulation, which triggers a new stoppage of the pump and sends a signal to the sequencer 6 to trigger the next phase (phase P.2), in which the first solenoid valve 14 ₁ is activated for venting the cells 12C1, allowing the deflation of the first cells 12c1, while the second solenoid valve 14 ₂ remains in a state of rest. The activation of the first solenoid valve 14 _{1 is} accompanied by a reference 6 ₃ of information to the comparator of the control means 4, ordering it to take the set pressure as the reference pressure for the inflation of the 12C2 cells. This triggers the restart and the operation of the pump for the reinflating of said second cells as the pressure detected in the cells does not reach the set pressure.

At t3, the setpoint pressure PC is reached in said second cells, which triggers the stopping of the pump. This new stop of the pump triggers the next phase (phase P.3), with activation of the activation of the second solenoid valve 14 ₂ and deflation of the second cells 12C2, and thus venting of the second cells. The activation of the second solenoid valve 14 _{2 is} accompanied by an information return to the comparator of the control means 4, which will compare the measured pressures in the cells with the regulation pressure range.

At t4, the detection of the maximum control pressure PRmax in said second cells 12C2, while the pressure in the first cells 12C1 is less than PRmin, that is to say outside the regulation range, triggers the setting in operation of the pump, without change of state of said first and second solenoid valves 14 ₁ and 14 ₂ . This causes a slowing down of the deflation of the second 12C2 cells and allows the first 12C1 cells to reach the regulation range at t5.

At t5, when the pressure is within the control range in the first and second cells 12C1 and 12C2, this controls the stopping of the pump. Stopping the pump the activation of a new phase of the cycle (phase P.4) with new activation of the second solenoid valve 14 ₂ venting of the second 12C2 cells. The new activation of the second solenoid valve 14 ₂ sends a signal to the control means of the pump to change the reference pressure by now comparing the pressure in the first cells with the set pressure. This causes the restart of the pump to perform reinflation of said first cells, until the set pressure is reached in said first cells.

At t6, when the set pressure is reached in said first cells, the detection of the set pressure in said first cells controls the stopping of the pump and a new phase of the cycle by resting said second solenoid valve 14 ₂ , the two solenoid valves 14 ₁ and 14 ₂ being at rest, which makes it possible to start, as at time t0, a new air transfer balancing phase from the first 12C1 cells to the second 12C2 cells.

At t0, t3 and t6, the quiescence of said second solenoid valves 14 ₂ at t0 and t6 and quiescent of said first solenoid valves 14 ₁ to t3 send a signal to the control means 4 of the pump to compare the pressure inside. cells with the control pressure, in this case a PRmax-PRmin range, as the reference pressure range. This is why, when the comparator of the control means 4 finds that the first cells at t1 and t2, and second cells at t4 and t5, are in the regulation range, whereas the second cells and first cells are not in the control range. the control range at t1 and, respectively, t4, it controls the restart of the pump at t1 and t4, and it controls the stopping of the pump at t2 and t5 for the opposite reasons, namely that the second cells 12C2 and first 12C1 cells are in the regulation range at t2 and, respectively, t5.

In the example shown in figure 1 , the central support zone 11C of the mattress 11 thus comprises eight inflatable cells 12C. These eight cells are organized in two groups of four cells 12C1, 12C2 distributed one cell out of two in the zone 11C and hydraulically interconnected by pipes 13 and the inflation device 1. During the alternating inflation cycles, the cells of the first 12C1 group are thus inflated when those 12C2 of the second group are deflated and vice versa, 12C1 cells are deflated when those 12C2 are inflated.

The inflator 1 is preferably housed in an integrated closed or closed foot area 15, in particular covered with foam, integrated with a support device 11 such as an inflatable cell therapeutic mattress 12 as shown in FIG. figure 1 . However, the inflation device 1 may also be of the ambulatory type and integrated into an ancillary and removable assembly of such a support device.

The inflation device 1 ( Fig. 1 ) of the invention comprises firstly inflation means constituted by a pump 2 with air compressor.

By reference again to the figure 2 , the inflation device 1 also comprises pressure sensors 3 inside the inflatable cells 12 of the support device 11, in particular a low-pressure sensor, and control means 4. Pressure regulation in the cells 12 is implemented with a comparator element between the measurement of pressure in the inflatable cells by the pressure sensors 3 and the measurement of the morphology sensor 9. If the pressure measured by the sensors 3 inside the cells is too high by relative to the comparative reference pressure deduced from the measurements by the morphology sensor 9, the means for deflating the mattress are controlled. On the other hand, if the pressure in the cells 12 is too low, the inflation means 2, which are electrically connected to said control means 4 and to the detection means of the inflation stop 5.

According to the invention, the inflation device 1 comprises detection means 5 connected to the inflating means 2 for detecting a stop of the inflating means 2. These detection means 5 essentially comprise a simple inverting logic gate converting the information of the inflation device. stopping the inflating means 2 as a signal for an alternating cycle sequencer 6, changes in the state of the solenoid valves and changing the reference pressures of the comparator element of the control means 4 for alternately inflating and deflating the inflatable cells of the inflation device. support and able to control these.

The sequencer 6 controls the four phases of the alternating cycle described above under the control of the detection means of the stop inflation 5.

At t0, phase # 1 (P.1): the transistor 6 ₂ sends a signal that causes the quiescent state of the solenoid valve 14 ₂ , and returns signal 6 ₃ to the comparator 4 to take as reference start-up of the pump, the regulating pressure.

At t2, phase 2 (P.2): the transistor 6 ₁ sends a signal which causes the activation state of the solenoid valve 14 ₁ , and returns signal 6 ₃ to the comparator 4 to take as reference starting the pump the set pressure.

At t3, phase 3 (P.3): the transistor 6 ₂ sends a signal that causes the quiescent state of the solenoid valve 14 ₁ , and returns signal 6 ₃ to the comparator 4 to take as reference starting the pump the regulating pressure.

At t5, phase # 4 (P.4): the transistor 6 ₁ sends a signal which causes the activation state of the solenoid valve 14 ₂ , and returns signal 6 ₃ to the comparator 4 to take as reference to start the pump the set pressure.

Said sequencer is connected to the control circuit of the two solenoid valves for emptying and filling the two series of cells and the control means of the inflation system 4 to switch the regulation of the so-called regulation pressure during the first and third phases to pressure setpoint during the second and fourth phases.

According to a particularly advantageous characteristic of the present invention, the inflation means of the device of the invention comprise a low voltage pump 2 powered at a voltage of 12 volts AC, generated from a 12-volt DC supply.

Complementarily, the power supply 7 may also include a power supply battery 10 able to maintain the operation of the inflation device in the event of a power failure. Such a battery 10 may be particularly useful during the transport phases of a bedridden patient on an inflatable cell support device, during which the supply of the electronic inflation device 1 must be disconnected from the electrical sector, in order to to maintain during the duration of the transport the alternate inflation process of the cells 12 of the support device 11. Such a power supply battery may in particular be of lithium-ion type in order to have a small footprint while having a storage capacity sufficient to provide autonomous power to the inflation device of the invention for a period of at least two hours.

To provide an AC supply voltage to the inflator from a DC voltage, the device of the invention comprises a power supply 7 comprising an "H" bridge of transistors 8. This transistor bridge is controlled by an oscillator frequency adjustable. It is the frequency of the oscillator 16 which sets the frequency of the AC voltage of the inflation system. This mode of feeding is advantageous because it makes it possible to optimize the point of operation of the inflation system and its efficiency. The performance of the inflation system is thus improved from 10% to 20% with reduced electrical energy consumption.

The inflation device of the present invention finally finally comprises, in an advantageous embodiment, a morphology sensor 9 placed under the mattress 11, able to measure the stresses applied by the body of a bedridden patient to the inflatable cells. of the support device 11, said morphology sensor 9 comprising in a preferred embodiment thereof at least one resistive force-sensing cell, in particular as described in the applications EP No. 08 163 149.1 and US N ° 12 / 199,869 in the name of the plaintiff.

These cells, better known by their English name "Force Sensing Resistors" or FSR (registered trademark) have an extremely simple structure and a particularly low price in comparison with other electronic components, which gives the pressure sensor an extremely low cost price. .

Moreover, the resistive force-sensing cells, which are electronic components whose impedance decreases the more the intensity of a force applied perpendicularly to their surface increases, are not very sensitive to noise and vibrations which facilitates the realization and the exploitation of the measures. Their wide range of impedance also allows the use of interface electronics and simplified operation as is that of the inflation device 1 of the invention.

The alternate inflation method of the invention is applied only to certain inflatable cells 12 of said mattress 11 in a particular support zone thereof, and in particular only to the cells 12C of the central support area 11C of the mattress 11 which serve to support the sacral zone of an individual lying down or sitting on the mattress 11, the inflatable cells in the support zone of the bust of a patient 11T and those of the 11P foot support zone being maintained constantly between the control pressure Pr and the set pressure due to their mounting upstream of the solenoid valves 14 ₁ and 14 ₂ .

It should be noted that the inflation and deflation time of 12C1, 12C2 cells varies depending on the patient. It is a function of the patient's morphology because it depends on the inflation time to arrive at the regulation pressure needed to properly wear it in the mattress 11 and the volume of air that the body takes by immersion in the inflatable cells 12C1, 12C2 of the central support zone 11C of the mattress.

This variation of the durations of the inflation and deflation phases during the alternating inflation process of the invention is for example demonstrated by the curves presented in FIGS. figures 7 and 4 . It can thus be noted in these figures that for an individual of 45 kg and 160 cm, the total duration of a complete cycle of inflation and deflation of a cell is of the order of 420 seconds approximately when this same cycle of full inflation and deflation of a cell is of the order of 700 seconds for an individual of 125 kg and 170 cm. Moreover, in the case of figure 7 the set pressure Pc to be reached to trigger the alternation of inflation of the cells 12C1 and 12C2 is lower than that in the case of the figure 4 , the regulation pressure range Pr being similar in both cases.

It should also be noted that a possible inclination of a portion of the mattress 11 also has an influence on the duration of a complete cycle of inflation and deflation of the cells 12C1, 12C2. Such inclination occurs especially frequently when a therapeutic mattress such as the mattress 11 of the figure 2 is used on medical beds equipped with a backrest.

The figures 6 and 5 , which represent the pressure variation curves in the cells 12C1 and 12C2 of the central support zone 11C of the mattress 11 of the figure 3 during the implementation of the alternate inflation method of the invention with an inclination of 60 ° of the support area of the bust 11T of the mattress relative to the support zone 11P legs, and show that such inclination to also as a consequence, an increase in the duration of the cycle of reinflation and deflation of the 12C1, 12C2 cells subjected to alternating inflation.

As can be seen from the curves presented to Figures 3 to 7 As well as from the foregoing description, the alternate inflation method of the present invention does not respond to fixed adjustment parameters but instead automatically adapts to the operating conditions of the support device on which the device is placed. as well as to the particular characteristics of the individuals installed on the support device so that the inflation pressures and the cycle times adjust automatically, which is essentially permitted according to the present invention by the use of the signal of stopping the inflation pump as a control element for alternating inflation of the cells of the support device.

Claims (12)

1. A method of inflating, in alternating manner, inflatable cells (12) of a support device (11) for supporting an element to be supported, which device is of the mattress type for supporting the body of a patient, said mattress being made up of cells that are inflatable with a fluid, in particular air, and having at least one zone (11C) made up of first and second series of inflatable cells (12C₁, 12C₂) referred to respectively as "first" cells and as "second" cells, the cells of each series communicating hydraulically or preferably pneumatically with one another and with inflation means comprising a pump, it being possible for the cells of each series of cells to be either in a state in which communication is open with the pump and with the cells of the other series of cells, or in a state in which communication is closed with the pump and with the cells of the other series and is open with the outside, in which state the cells are connected to the surrounding air, in which method alternating deflation and re-inflation cycles are performed during which each of said series of cells is deflated and then re-inflated in alternation and in succession, said first cells (12C₁) being deflated and then re-inflated simultaneously respectively with the re-inflation and with the deflation of said second cells, the alternating deflation and re-inflation steps for deflating and re-inflating, in alternation, said first and second cells of the support device including at least one step of inflating said cells to a value of at least one reference pressure (Pc, Prmax,Prmin)whose value is determined on the basis of a continuous measurement taken by means of a "morphology" sensor (9) measuring the stress generated by the patient's body on the cells, such that the alternating deflation and re-inflation steps for deflating and re-inflating, in alternation, said first and second cells take place in a cycle controlled by said inflation means being switched on or off, which switching on or off is controlled as a function of the values of the pressures of the fluid measured inside said cells and of comparison of said values with a said reference pressure value, and said inflation means being switched on or off causes said first or second cells to be put into the state in which communication is open with said inflation means or into the state in which communication is closed therewith.
2. A method according to claim 1, wherein:

   · said inflation means are switched on or off as a function of the values of the pressures of the fluid measured in said cells and of comparison of said values with a value of a first reference pressure or "regulation pressure" that is determined as a function of the morphology of the patient, and with a value of a second reference pressure or "setpoint pressure" that is greater than said regulation pressure and that is computed relative to said regulation pressure; and

   · said inflation means being switched on or off controlling which of said first and said second reference pressures is chosen to be taken into account for said comparison for the next switching on or off of the inflation means during a said cycle.
3. A method according to claim 2, wherein:

   · said first cells are connected one after another in series;

   · said second cells are connected one after another in series;

   · the following successive steps are performed, in which:

   a) when (tr) all of the cells of the first and second series are inflated to a pressure corresponding to a said regulation pressure (Pc), the pump being off, and the cells of each series of cells being in the state in which communication is open with the pump and with the cells of the other said series of cells, detection of said regulation pressure in said first and second cells, causes:

   a-1) said first cells (12C₁) to deflate by being connected to the surrounding air; and

   a-2) said second cells (12C₂) to be over-inflated by switching the pump on until a determined setpoint pressure (Pc) is reached that is greater than the regulation pressure; and

   b) when (t₃) the setpoint pressure is reached in said second cells (12C₂), detection of said setpoint pressure in said second cells causes the pump to be switched off and each series of cells to be put into the state in which communication is open with the pump and with the cells of the other series of cells, thereby making it possible for fluid to be transferred from said second cells to said first cells, and thus for said second cells to be deflated, and, simultaneously, for said first cells to be re-inflated, to a said regulation pressure; and

   c) when (t₅) all of said first and second cells are at a pressure corresponding to a said regulation pressure, detection of a said regulation pressure in said cells causes the pump to be switched off, which switching off of the pump causes:

   c-1) said second cells to be deflated by being connected to the surrounding air; and

   c-2) said first cells to be over-inflated by switching the pump on until a said setpoint pressure (Pc) is reached; and

   d) when (t₆) said setpoint pressure is reached in said first cells, detection of said setpoint pressure in said first cells causes the pump to be switched off and each series of cells to be put into the state in which communication is open with the pump and with the cells of the other series of cells, thereby making it possible for fluid to be transferred from said first cells to said second cells, and thus for said first cells to be deflated, and, simultaneously, for said second cells to be inflated, to a said regulation pressure; and

   e) where applicable, the cycle of steps a) to d) is reiterated.
4. A method of inflating, in alternating manner, according to claim 2 or 3, wherein:

   · said first cells are connected to at least a first solenoid valve (14₁) making it possible either to establish communication that is open with the pump and with said second cells when the solenoid valve is in a "rest" state, or to connect said first cells to the surrounding air by putting them in the state in which communication is closed with the pump and with said second cells and in which communication is open with the outside, when the solenoid valve is in an "activation" state;

   · said second cells are connected to at least a second solenoid valve (14₂) making it possible either to establish communication that is open with the pump and with said first cells when the solenoid valve is in a rest state, or to connect said second cells to the surrounding air by putting them in the state in which communication is closed with the pump and with said first cells and in which communication is open with the outside, when the solenoid valve is in an activation state; and

   · the pump being switched off causing said first and second solenoid valves to be put into the activation or the rest states.
5. A method according to any one of claims 1 to 4, wherein:

   · the regulation pressure corresponds to a pressure lying in a "regulation" range (PRmax-PRmin) ; and

   · in steps b) and d), during said transfer, when (t₄, t₁) the maximum regulation pressure (Prmax) is detected respectively in said second cells and in said first cells even though the minimum regulation pressure (PRmin) is not reached respectively in said first cells and in said second cells, the pump is caused to be switched on for inflating said first cells and said second cells, respectively; and

   · in steps a) and c), the pump is caused to be switched off by detection of a pressure in said first and second cells that lies in said regulation range, and the pump is switched back on in steps a-2) and c-2) by detection of a pressure in said cells that is less than the setpoint pressure.
6. A method according to any one of claims 2 to 5, wherein the "setpoint" fluid pressure is determined relative to the regulation value and to be greater by at least 10% than the "regulation" pressure, and preferably greater by at least in the range 15% to 30% than said "regulation" pressure.
7. An inflation device for inflating (1), in alternating manner, a support device for supporting a patient to be supported, in particular a mattress or a cushion for supporting the body of a patient, said mattress being made up of cells that are inflatable with a fluid, in particular air, having at least one zone (11C) made up of first and second series of inflatable cells (12C₁, 12C₂) referred to respectively as "first" cells and as "second" cells, the cells of each series communicating hydraulically or preferably pneumatically with one another and with inflation means comprising a pump and enabling to carry out a method according to any one of claims 1 to 6, said inflation device comprising:

   · said inflation means (12);

   · hydraulic communication means (13) connecting said inflation means to said inflatable cells;

   · said pressure measurement means (3) for measuring the pressures inside said inflatable cells;

   · a said morphology sensor (9) suitable for measuring directly the stress applied by a said patient on said inflatable cells of the support device and for determining said reference pressure value,; and

   · said control means (4) for controlling said inflation means, said control means (4) for controlling said inflation means are connected to said pressure measurement means (3) and to said morphology sensor (9) and being suitable for causing said inflation means to be switched on or off as a function of the value of the pressure of the fluid that is measured in said cells by said pressure measurement means (3) by comparing said value with at least one said reference pressure value determined by said morphology sensor (9).
8. A device according to claim 7, further comprising a morphology sensor (9) suitable for measuring the interface pressure applied by a said patient on said inflatable cells of the support device and for determining said regulation pressure value and said setpoint pressure value, said sensor being connected to said control means for controlling the inflation means.
9. A device according to claim 7 or 8, further comprising:

   · said first and second solenoid valves (14₁, 14₂) connected to respective ones of said first and second cells and to said inflation means, said solenoid valves (14₁, 14₂) being suitable for making it possible either to establish communication that is open with the pump and with said second cells and, respectively, with said first cells when the corresponding solenoid valve is in a said rest state, or to connect said first cells and, respectively, said second cells to the surrounding air by putting them in the state in which communication is closed with the pump and with said second cells and, respectively, said first cells and in which communication is open with the outside, when the corresponding solenoid valve is in a said activation state; and

   · means for detecting (5) when the pump is off, which means are connected to a sequencer (6) suitable for causing said solenoid valves to be put into the activation state or into the rest state in succession, and preferably for causing said first or second reference pressures to be chosen for being taken into account in said comparison, in a determined sequence.
10. A device according to any one of claims 7 to 9, wherein said inflation means comprise a low-voltage pump powered under a voltage of 12 volts AC.
11. A device according to claim 10, further comprising a power supply (7) including a transistor bridge (8).
12. A device according to any one of claims 7 to 11, further comprising a power supply battery (10) suitable for causing the inflation device to operate in the event that the mains power supply is interrupted.

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