WO2009004519A2 - Pump for a multi -partitioned, inflatable device and dynamic-action, bedsore -preventing support made with the device - Google Patents

Abstract

A pneumatic pump for inflatable partitions of a support, and a bedsore-preventing mattress suitable for use with such pump, are disclosed. The pump is of the type suited to deliver pressurised air to a plurality of outlet ports which are in communication with respective flexible vesicles/bags (11a-11c) arranged in a circle, squashing means (16) being further provided rotating about the axis (18) of said circle and capable of applying rotary compression to said vesicles (11a-11c), said vesicles further being connected, through one-way valves (V), to a common pressure -loading circuit (20).

Description

PUMP FOR A MULTI -PARTITIONED , INFLATABLE DEVICE AND DYNAMIC-ACTION, BEDSORE -PREVENTING SUPPORT MADE WITH THE DEVICE

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The present invention refers to a pressure pump for a multi- partitioned device and to a bedsore-preventing apparatus employing said pump .

As known, bedsores are a dangerous complication of all illnesses forcing a patient to stay in an obligated position (particularly in bed) for a long time. A localised and prolonged compression of the skin causes conditions due to impaired blood circulation, which causes cell death and the onset of degenerative processes of the skin which cause precisely the development of bedsores.

In the health sector, there exists hence the need to offer to such patients (in particular to elderly people) a support which prevents bedsore formation.

In the prior art, a variety of different solutions for bedsore- preventing mattresses have been described, intended to maintain adequate pressure on the patient's body. In particular, it is wished for these mattresses to guarantee well-distributed support - so as to guarantee specific low pressure - and preferably a continuous shift of resting points, in order to promote blood circulation and prevent pressure localisation.

Examples of these known supports are disclosed in WO07/25611, EP94594, US5956787, NL1006009, DE19632611, WO97/17930. In general, the prior art provides to arrange one or more mattresses filled with a working fluid (water or air) , which are alternatively subjected to pressure and bled to offer dynamic support to the patient. This dynamic support meets the desired requirements, i.e. shifts the point of pressure application, does not produce localised points of high pressure and promotes blood circulation in the patient .

However, so far no entirely satisfying mattress arrangements have been offered which allow to obtain a dynamic action with an inexpensive and simple-construction structure. Moreover, all known systems, in order to control over time the pressure in the various mattress partitions, resort to controlled valves or to compressor apparatuses requiring the use of complex adjustment and control devices which are delicate, scarcely reliable and expensive.

A first object of the present invention is hence to offer a pumping system for a multi-partitioned, inflatable device, such as a bedsore-preventing mattress, which is simple and devoid of complex adjustment and control devices. A second object is to provide an inexpensive and effective bedsore-preventing mattress which offers a configuration particularly- suitable to be used with a simplified pump.

Such objects are achieved through the invention as disclosed in its essential features in the accompanying claims.

In particular, according to a first aspect of the invention, a pneumatic pump for inflatable partitions of a support is provided, of the type suitable to deliver pressurised air to a plurality of outlet ports connected to a respective plurality of said partitions, wherein the outlet ports are in communication with respective vesicles/flexible bags arranged in a circle, and wherein rotating squashing means are further provided which are capable of applying rotary compression to such vesicles, the vesicles further being connected, through one-directional valves, to a common pressure- loading circuit .

According to another aspect of the invention, a bedsore- preventing system is provided, comprising such pump and a bedsore- preventing mattress, said mattress comprising a plurality of independent, inflatable partitions, wherein each partition has a series of parallel, tubular chambers joined by thin connecting portions, said portions being of a length which is substantially an N- 1 multiple of the width of the tubular chambers, where N is the number of mattress partitions which may be mutually overlapped, offset in a crosswise direction to the tubular chambers. Further features and advantages of the device according to the invention will in any case be more evident from the following detailed description of a preferred embodiment of the same, given by way of example and illustrated in the accompanying drawings, wherein: fig. 1 is a perspective view of an exemplifying mattress partition according to the invention; fig. 2 is a schematic view illustrating the 3 -partition composition of the mattress according to the invention; fig. 3 is a diagram showing the working principle of the system according to the invention; fig. 3A is a schematic cross-section view of the pump according to the invention with the relevant connections ; fig. 3B is a schematic view of a valve enclosed in the circle H of fig. 3A; fig. 4 is a more detailed, cross-section view of the pump of fig. 3A, but from an opposite direction; fig. 5 is a longitudinal-section view of a first embodiment of the pump of the invention; figs. 6A-6B are perspective, side elevation and exploded views, respectively, of a squashing cylinder of the pump of the invention; figs. 7A and 7B are more detailed longitudinal cross-section and front elevation views, respectively, of the cylinder device of fig. 6A; fig. 8 is a schematic perspective view of the pump according to the embodiment of fig. 5; figs. 9A-9C are perspective, cross-section and bottom plan views, respectively, of a pump according to a second embodiment of the invention; fig. 10 is an elevation side view of the pump of fig. 9A; and fig. 11 is an elevation front view of a vesicle included in the pump of fig. 10.

A bedsore-preventing mattress consists, in a manner known per se, of a series of flexible chambers within which a pressurised fluid is intended to be let in, in particular air. The air is let in at varying pressures into the various mattress chambers, according to a time sequence which creates a dynamic mattress movement.

In order to achieve such result and arrange a structure suitable for use with a simple pump, the mattress according to the invention consists of a series of independent partitions, each provided with flexible and inflatable chambers .

Fig. 1 shows one of such partitions. It consists of a series of inflatable portions 1 mutually connected by thin connecting portions 2. For example, inflatable portions 1 are in the shape of tubular chambers, arranged crosswise to the longitudinal development of the partition, made of plastic material. The connecting portions 2 consist of simple sheets of plastic material, of a suitable thickness (for example 2 mm), thermowelded to two adjacent inflatable chambers 1. The number of chambers 1 and of connecting portions 2 is a function of the mattress length which is intended to be provided. In the drawings a partition consisting of five inflatable chambers 1 having an elliptical section and an extension of 100 mm is exemplifyingly shown, alternated with connecting portions having a length of 200 mm, for an overall length of 1.300 mm.

The mattress consists of a number N of these mutually overlapping partitions, intended to be differently pressurised over time, so as to produce an overall dynamic effect .

In particular, the individual partitions are overlapped in a mutually offset manner, as highlighted in fig. 2.

Due to the fact that the connecting portions 2 have a length equal to twice (N-I) the extension of the individual chambers 1, it is possible to overlap three (N) partitions, arranging the chambers of the three series in a mutually adjoining, repetitive way, so that the individual tubular chambers of the subsequent series fill the gap between two adjoining chambers of the previous series. Thereby a modular repetition of N chambers belonging to N different series/partitions is obtained in the mattress.

In the following, reference will always be made to the version with three distinct series, which for various reasons was the preferred one, but it is not ruled out that two series only, or more than three, may also be provided, provided the configuration of the supply pump is changed accordingly, as will be shown in the following.

The whole structure consisting of the three series of partitions is then housed in a larger soft body which makes up the proper mattress to be arranged on the patient's bed. By sequentially pressurising the three different series of chambers, it is then possible to obtain a sort of "wave effect" in the mattress, which causes a favourable dynamic action on the patients.

Operationally, the different partitions are filled with air at a pressure sufficient to maintain them inflated and semirigid; the subsequent application of an additional overpressure, distributed in an original way between the different partitions, further ensures the dynamic behaviour of the mattress.

In order to distribute such overpressure across the mattress partitions, use is made of a pump which will be illustrated in the following.

Pig. 3 shows schematically the pneumatic layout of the system. The individual mattress partitions are referred to by an own representational chamber, Zl, Z2 and Z3, respectively.

The three partitions are in communication with a tank A at the desired static pressure. At the same time, according to an original principle of the invention, the individual partitions communicate with an equal number of pressure vesicles Vl, V2 and V3 - themselves communicating with tank A - intended to alternately pump pressurised air into the respective partitions Zl, Z2 and Z3 thanks to the action of an actuator B .

As a matter of fact, according to the invention, in order to pressurise the mattress partitions, an air pump is used - consisting of vesicles Vl-V3 and of actuator B - conceived as described in the following. With reference to figs. 3A and 4, the pump according to the invention comprises a cylindrical container 10 within which three flexible bags or vesicles lla-llc are housed, and a squashing cylinder IS .

The three flexible bags lla-lie are equally spaced apart arranged along the inner cylindrical wall of container 10, with suitable attaching means, such as even a simple band of thin Velcro. They have such a width to occupy an arc of about 90° -120° and a length depending on various factors, such as the desired volume; as an example, according to the embodiment shown in fig. 5 wherein the container has a diameter of about 315 mm, the vesicles have a crosswise development of about 255 mm and a length of about 300 mm. The vesicles lla-lie are intended to act as a bellow, inflating and deflating to alternately transfer pressure to the respective mattress partitions. For such purpose, they must have adequate flexibility, resistance to fatigue and to tear: a suitable material is a polyurethane film, for example the Eterfilm™ double with thickness 3.6 mm and weight 430 g/tn² manufactured by Giovanni Crespi S.p.A.

Each vesicle further has a one-way compensation valve 12 and a connection 13. Valve 12 is intended to guarantee that any pressure losses in the vesicle/mattress circuit be restored by the environment system, within the cylindrical container 10, under constant pressure. Connection 13, instead, represents an inlet/outlet port of bag 11 and is intended to cross the thickness of container 10 to be connected to the distribution circuit which will be illustrated below.

Squashing cylinder 16 is rotatably mounted at the distal ends of a pair of arms 17a and 17b, in turn rotatably mounted on the longitudinal central axis of cylindrical container 10.

In particular, as visible in figs. 6A-6C, arms 17a and 17b are keyed with their proximal end on a common drive shaft 18 rotatably mounted on the axis of container 10. Drive shaft 18 is intended to be driven into rotation by a driving system (not shown in figs. 4-7B) to cause squashing cylinder 16 to push in rotation onto the three vesicles lla-llc.

According to a preferred embodiment, squashing cylinder 16 does not enter directly in engagement with vesicles lla-llc, but sufficiently-flexible squashing plates 14 are provided, hinged at 15 along their leading edge to the cylindrical wall of container 10. Plates 14a-14c have an own curvature substantially equivalent to that of cylinder 10 and are arranged between squashing cylinder 16 and the respective vesicles. The hinge 15 of each plate 14 is arranged on the leading edge of the plate, i.e. on the edge which - with respect to the sense of rotation R of shaft 18 - is first hit by cylinder 16.

Squashing plates 14 are intended to distribute in a more even and balanced way the pressure of cylinder 16 on the respective vesicles 11, so as to avoid premature wear of the vesicles or points of overpressure which might quickly lead to breaks in the plastic film of the vesicles.

In fig. 4 it can be seen that vesicle lie is compressed by the action of plate 14c, which is in turn compressed towards the wall of container 10 by squashing cylinder 16.

As can be detected clearly also in fig. 4, cylinder 16 is mounted on the respective arms 17a and 17b so as to follow a path at a certain distance from the inner wall of container 10. As a matter of fact, cylinder 16 must compress the vesicles in a bellowlike manner, but without causing a disruptive action on the vesicles, nor on squashing plates 14 and on the hinges 15 thereof. For example, in the furthermost point from the axis of rotation 18, cylinder 16 passes at a distance of about 12 mm from the wall of container 10. The pneumatic circuit is shown also in fig. 3A, as well as in a sketchy way in fig. 2.

The connections 13 of the three vesicles are joined, through hoses Ta, Tb and Tc, to respective separate partitions of the bedsore- preventing mattress, which partitions are not in mutual, fluid communication.

Moreover, a common tubular ring 20 is provided, which puts in communication connections 13a-13c through one-way valves, as illustrated in fig. 3B. Valve V, in substance, is arranged between individual hose Ta-Tc and common tubular ring 20: such valve is arranged so as to open exclusively when the pressure in ring 20 is higher than the pressure existing in the respective circuit consisting of the vesicle/hose/mattress partition.

On tubular ring 20 an additional bleeding valve 21 is further provided, which allows the outlet of air from ring 20 in case of overpressure. Finally, a manual pumping device P, capable of loading the initial pressure in the system, is connected to ring 20.

Operationally, the pump according to the invention works in the following way.

Once the three mattress partitions are connected to the three respective pump vesicles, through corresponding hoses Ta-Tc, air at a low pressure is initially introduced in the circuit through the manual pumping device P. The pressure distributes itself in ring 20 and, due to the presence of non-return valves V, inflates to the desired pressure the chambers 1 of the partitions and vesicles lla-llc. Upon reaching a predetermined maximum pressure, bleeding valve 21 opens and allows to let out any excess pressure.

Once the initial pressure loading phase has ended, squashing cylinder 16 is driven into rotation about the shaft 18, in the direction shown by arrow R. In its movement, cylinder 16 alternately compresses the three vesicles, causing the temporary compression of the volume thereof, so as to increase the air pressure in the respective portion of the pneumatic circuit. In turn, the compression and emptying of each vesicle causes the inflation of the respective partition connected thereto, thereby causing a dynamic supporting effect on the patient lying on the mattress.

Figs. 9A-9C, 10 and 11 show a different embodiment of the pump according to the invention, wherein parts equivalent to the preceding description are shown with identical reference numbers .

In this case a possible embodiment of the motorisation drive of shaft 18 is shown. As a matter of fact, said shaft protrudes from the lower side of the pump and engages with a large-diameter driving wheel 100. Wheel 100 in turn meshes with a transmission belt 101 which receives the motion from a pinion 102 integral with the drive shaft 103 of an electric motor M.

This configuration, advantageously, provides a transmission which takes up a small space in the lower part of the pump, which may hence be maintained at a short height from the floor through a series of small feet or rubber heels T. Motor M may be arranged laterally to the pump, without affecting the vertical bulk of the pump and being easily accessible for ordinary control and maintenance operations.

According to the embodiment shown in these last drawings, the vesicles further have special-construction loading valves.

The vesicles are attached to the inner wall of container 10 only along one leading edge thereof, in the proximity of the hinges 15 of squashing plates 14.

Within each vesicle a small hose 105 is provided, arranged in the proximity of the leading edge and substantially aligned to the axis of shaft 18. One end of hoses 105a-105c protrudes laterally from respective vesicles lla-lie with a passage port which is in turn connected with a socket 106a-106c arranged outside the pump for connection to hoses Ta-Tc. Inside hoses 105a-105c, one-way valve means are further provided, for example in the shape of a simple small sphere 107 slidable within the small hoses . Such configuration replaces the one indicated with valve V of the first embodiment. As a matter of fact, small sphere 107, when the corresponding vesicle is compressed, obstructs connection 106 in the direction of common hose 20, so that the pressurised air flows out only towards the corresponding supply hose T and not towards the other partitions . Similarly to the preceding embodiment, in this case too, a common hose 20 - developing along an arc of a circle of about 270° - for the distribution of the initial pressure in the circuit is further provided. As can be understood from the description supplied above, the pump according to the invention allows to perfectly achieve the objects set forth in the preliminary remarks.

As a matter of fact, the pump is extremely simple, since it does not provide any electric/electronic control, nor controllable valves, but simply a series of vesicles (three in the embodiment shown) arranged in a circle and which are compressed in succession by a rotating cylinder. The actuation of the vesicles causes a consequent inflation/deflation of the separate partitions of a pneumatic mattress, so as to then generate a dynamic effect particularly suited for reducing bedsore problems .

Such pump finds a particularly useful application with the mattress described above, wherein the individual partitions are coupled offset with respect to one another and are individually air supplied by the respective outlet ports of the pump . However, it is understood that the invention is not limited to the particular embodiments illustrated above, which represent only non-limiting examples of the scope of the invention, but that a number of variants are possible, all within the reach of a skilled person in the field, without departing from the scope of the invention. In particular, as mentioned, the vesicles and the corresponding mattress partitions may also be in a different number from what has been detailed.

Moreover, despite not having been described in detail, it is evident that the electric motor may simply comprise an ON/OFF switch or even a speed controller in order to drive it into rotation at the speed best suited to circumstances.

Again, the manual pump may be replaced by any other external pumping system (such as even a small electric compressor) which is capable of bringing the system to the desired initial pressure. Finally, although the pump according to the invention has been specifically provided for a bedsore-preventing mattress, it is not ruled out that it may be applicable to any other seating device not necessarily used in a hospital setting, such as an armchair.

Claims

1) Pneumatic pump for the inflatable partitions of a support, of the type suitable to deliver pressurised air to a plurality of outlet ports connected to a respective plurality of said partitions, characterised in that said outlet ports are in communication with respective flexible vesicles/bags (lla-llc) arranged in a circle, squashing means (16) rotating about the axis (18) of said circle and capable of applying rotary compression to said vesicles (lla-llc) being further provided, said vesicles being further connected - through one-way valves (V) - to a common pressure-loading circuit (20) .

2) Pneumatic pump as claimed in claim 1) , wherein said vesicles/bags (lla-llc) adhere to a static, cylindrical inner wall of a container (10) , said rotating squashing means being capable of compressing said vesicles/bags (lla-llc) against said static wall and said outlet ports comprising connections which protrude from said container (10) .

3) Pump as claimed in claim 2) , wherein said rotating squashing means comprise a squashing cylinder (16) mounted rotating shifted with respect to said circle axis (18) .

4) Pump as claimed in claim 2) or 3) , wherein said vesicles/bags (lla-llc) are attached to the cylindrical wall only along a leading edge thereof .

5) Pump as claimed in any one of claims 2) to 4) , wherein squashing plates (14) are further provided, arranged between each flexible vesicle/bag (lla-llc) and said rotating squashing means, hinged along an edge (15) to said static, cylindrical wall.

6) Pump as claimed in claim 5) , wherein said squashing plates (14) are curved and relatively rigid. 7) Pump as claimed in claim 3) , wherein said squashing cylinder (16) is mounted on a drive shaft (18) coaxial with said circle axis and driven into rotation by a driving system.

8) Pump as claimed in claim 7) , wherein said drive shaft (18) protrudes with one end below said container (10) within which said driving system is coupled, which comprises a gear/belt/pinion transmission and an electric motor (M) .

9) Pump as claimed in claim 8) , wherein said transmission occupies a reduced-height space below said container (10) , said container having resting feet which keep it suitably raised from the floor.

10) Pump as claimed in any one of the preceding claims, wherein said common pressure-loading circuit (20) is connected to an outer pump (P) and said one-way valves (V) are capable of opening when the pressure in the common circuit (20) is above that existing in said vesicles/bags (lla-llc) .

11) Pump as claimed in claim 10) , wherein said common pressure- loading circuit (20) further has a bleeding valve (21) which opens in case of overpressure.

12) Pump as claimed in any one of the preceding claims, wherein said vesicles/bags (lla-llc) comprise inside a small hose (105) equipped with a sphere valve (107) , the small hose (105) being arranged substantially parallel to the circle axis (18) and having one end protruding from said vesicles/bags (lla-llc) .

13) Pump as claimed in any one of the preceding claims, wherein said vesicles/bags (lla-llc) consist of coupled and thermowelded sheets of plastic material. 14) Pump as claimed in claim 13) , wherein said plastic material is polyurethane .

15) Pump as claimed in any one of the preceding claims, wherein said vesicles/bags (lla-llc) are three and each of them occupies an arc of a circle between about 90° and 120° about said circle axis (18) .

16) Bedsore-preventing support to be coupled with a pump as disclosed in any one of the preceding claims, of the type comprising a plurality of independent inflatable partitions, characterised in that each partition has a series of parallel tubular chambers (1) connected by thin connecting portions (2) , the length of said portions being substantially a multiple N-I of the width of said tubular chambers (1) , where N is the number of mattress partitions, and in that said partitions may be overlapped in a mutually offset manner in a crosswise direction to the tubular chambers (1) .