MXPA97006560A - Support device with a plurality of thermal zones that provide local cooling - Google Patents

Abstract

The present invention relates to an apparatus for supporting the body of a human being or of an animal, while at the same time selectively cooling the weight-bearing areas of the body, which consists of: a cooling layer having a plurality of zones: a surface disposed on the cooling layer, each zone of the cooling layer being arranged to cool a respective portion of the surface; means for selectively operating one or more zones of the plurality of zones to cool a portion; of the surface being pressed by an area of the body that bears weight, and means for detecting a place where the body is applied pressure to the surface, the means being coupled to selectively operate the means to detect and react to an indication of pressure to operate at least one zo

Description

SUPPORT DEVICE WITH A PLURALITY OF THERMAL ZONES THAT PROVIDE LOCALIZED COOLING BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to an apparatus for supporting at least a portion of the body of a human being or of an animal, with localized or concentrated cooling in the areas of the weight bearing portion. Localized or concentrated cooling reduces the risk of damage to areas of the body that support the weight of patients who must be in bed or in wheelchairs for long periods of time.

It is known that the application of pressure to a patient's skin over a prolonged period causes ulcerations due to pressure. Weight-bearing areas of the body surface are exposed to pressures that can easily exceed 100 mmHg (torr.). It has been shown that blood flow ceases in capillaries that are exposed to compressive pressures exceeding 25 torrs. Consequently, it can be expected that the areas of the body surface and the subcutaneous tissues that support weight have an inadequate blood flow or even a total lack of blood flow during the time that the weight is being supported.

The normal cellular metabolism depends on the blood circulating properly, so that it provides oxygen and nutrients to eliminate waste products. Prolonged interference of the local circulation results in a sequence of events divided into two parts, beginning with ischemia (a severe reduction in the supply of blood and oxygen to the tissues) and ending with a necrosis (irreversible cell and tissue death, which results in a slough).

Normally people change positions when they are in a chair or get up and walk to relieve the pressure on their buttocks. Usually people turn from side to side in bed, while they sleep, to periodically redistribute their weight to a different area of the surface of their body. In general, this movement is a reaction to pain or discomfort caused by the ischemia of the skin tissue, or deep subcutaneous tissue, which is supporting weight. Patients bedridden or in wheelchairs, or patients who are in operating room tables, may not be aware of ischemic pain if they have a brain or spinal cord injury, paralysis, dementia, prolonged surgery with anesthesia, or prolonged sedation or mechanical breathing. Alternatively, also serious diseases, neuromuscular disorders or nervous system injuries can prevent the patient from moving even if they are realizing that they have ischemic pain.

In the operated patients, the incidence of ulcerations due to pressure fluctuated between 12% and 66% in different studies performed. Surveys performed on patients in general hospitals indicate that between 3-4.5% of all patients develop ulcerations due to pressure during their hospitalization. Pressure ulcers usually develop near regions of the body that have a bony prominence near the skin. More than 80% of all pressure ulcerations occur in the following five places: 1. Sacrococcygeal region (upper part of the gluteus), supine position. 2. Great trochanter (lower part of the hip), lateral recumbent position. 3. Ischial tuberosity (lower part of the gluteus), sitting position. 4. Tuberosity of the calcaneus (heel), supine position. 5. Male lateral (external ankle), lateral recumbent position.

Patients with surgical or bed-ridden operations are not the only patients susceptible to developing ulcerations. For example, paralyzed patients spend much of their lives in wheelchairs. There is a study that indicates that the incidence of pressure ulcers is 21.6% in paraplegics and 23.1% in quadriplegics.

The equipment for the prevention of pressure ulcers has been concentrated in three areas: 1. Flip or periodically move the patient to minimize the time pressure is applied to any surface area. The fabric is given time to be perfused again during the period of time when pressure is not being applied. 2. Passive support surfaces (cushions, mattresses and mattresses of all kinds), which can use special materials or unique forms to minimize the pressure exerted on any given point of the body surface. Many types of materials have been tried, including: different types of polymeric foams, polymeric gels, and chambers filled with water and air. 3. Active support surfaces, such as a series of air-filled chambers that inflate and deflate alternately to automatically distribute the pressure.

Taking into account the high incidence of pressure ulcerations, despite the availability of many of these passive support surfaces (various materials and shapes), it is clear that the simple fact of distributing pressure to a larger surface area, and on itself It will not effectively prevent pressure ulcerations. Although active support surfaces have been used to prevent pressure ulcerations, it is clear that they are very expensive, uncomfortable and noisy. Consequently, it is not possible to use active support surfaces in many situations to prevent pressure ulcerations.

Finally, apart from the obvious pain and risk to the patient's health (with chronic infections in chronically open wounds), pressure ulcerations are extremely expensive and very slow to heal. The healing of an ulceration by normal pressure costs between $ 30,000 and $ 40,000, and takes between 3 and 6 months approximately. The high incidence of pressure ulcerations, the lack of a proven method to avoid pressure ulcerations, and the extremely high cost of curing them once they develop, indicate that there is a great need for new technology.

It is reasonable to assume that heat is an important factor in the formation of pressure ulcerations. All tissues increase between 7 and 10% metabolic rate each time the temperature increases 1 ° C. The increased metabolic rate increases the oxygen demand of cells by 7-10% similar for every 1 ° C increase in temperature. In a patient whose tissue perfusion is already compromised by external pressure or vascular insufficiency, this increased metabolic oxygen demand could increase the speed of tissue damage. We hypothesized that this increased metabolic demand was the cause of the frequent "burns" that were observed after a warm-water mattress therapy during surgery, despite the relatively low temperatures of the mattresses (39 ° -42). ° C). These low temperature injuries can result in damage to the entire thickness of the skin, which looks identical to third-degree burns that result from exposing the skin to high temperatures. Although the damage throughout the thickness of the skin is identical to that of a thermal injury caused by high temperature ("burn"), in fact the injury is caused by pressure necrosis, which is accelerated due to the higher metabolic rate of the skin. tissue. Although this interrelation between temperature, pressure and tissue ischemia is logical from the scientific point of view, it had never been proven before we carried out our recent experiments.

In addition, it is known that hypothermia decreases the cellular metabolic rate and increases the tolerance of the cells to periods of inadequate blood flow. This is the reason why patients are cooled when they have a cardiac vascularization. Consequently, we hypothesize that cooling the skin and subcutaneous tissue will make it more time, in fact, to appear a lesion when there is a risk of ischemia caused by inadequate local blood flow resulting from the pressure exerted against that tissue. .

To test these hypotheses, we created a porcine model to investigate the formation of pressure ulcers. Twelve metal discs were applied to the back of an anesthetized pig. The pressure in the skin under each disc was approximately 100 torres (totally occlusive to the blood flow), during a lapse of 10 hours. The temperature of the discs was carefully controlled at 25 ° C, 35 ° C, 40 ° C and 45 ° C. The normal body temperature of a pig is 38 ° C (the normal temperature of the human body is 37 ° C). The severity of the resulting tissue lesions was directly correlated with the increase in temperature. No tissue damage was found under the 25 ° C discs. Under the discs of 45 ° C severe damage was seen in the skin, in the subcutaneous tissues and in the deep ones. The discs of 35 ° C and 40 ° C also caused serious damage, but moderate in relation to those of extreme temperatures. The results of this experiment clearly indicate that our two hypotheses were correct. 1. Even moderate heat will accelerate the speed of tissue injury due to pressure induced ischemia. 2. Moderate cold will protect against tissue damage due to ischemia caused by pressure.

For decades, mattresses have been used in which fresh, or even cold, water circulates to cool patients with fever. However, experience has shown us that the application of cold in very large areas of the body surface is very annoying and causes hypothermia and tremor. 2. Description of Related Inventions In the prior invention of US Pat. No. 3,738,702, a seat structure is described which cools a portion of the human body resting on the seat, in reaction to body heat, at the part where the body contacts the body. seat. In order to maximize the sensitivity of the cooler in relation to body heat, the cooler is placed as close as possible to the surface of the seat with which the body contacts.

SUMMARY OF THE INVENTION The object of this invention is to provide an article, such as a bed mattress, or a chair or wheelchair cushion having a surface to support at least a portion of the body of a human being or of an animal ("portion of the body"). body "). According to this invention, specific contact areas of "high" pressure of the portion of the body that is between the surface and the skin of the body portion (greater than 20-25 torrs) are selectively cooled to remove the heat. of those specific areas.

In patients who are supine or seated, the metabolic heat generated by the ischemic tissue is trapped by insulating cushions and raises the temperature of the tissue. Metabolic heat can not be eliminated internally due to inadequate blood flow, nor can it be eliminated externally due to the thermal insulation characteristics of cushions or cushioned mattresses. Metabolism continues (anaerobically) despite inadequate blood flow, and the heat generated by this metabolism continues to accumulate. Our studies with pigs show that any heating of the tissue is obviously harmful, and that cooling the tissue below body temperature is beneficial to avoid tissue injury caused by pressure. A cooling below the normal body temperature will be beneficial. Accordingly, this invention prevents the formation of metabolic body heat naturally generated in the ischemic tissue. The adjacent surface areas of the body that are not experiencing high pressure will not be cooled. Due to the minimal blood flow in the high pressure areas, the cooling effect will be considerably isolated in these tissues and will not cause total body hypothermia or discomfort.

Our invention is based on the essential observation that areas of the body that are subject to an increased risk of ischemia by supporting the weight of the body, they can be cold applied selectively by an apparatus that is subdivided or divided into zones, and each of those zones is capable of applying cooling to a surface that is supporting weight. According to an optional element, such cooling may be provided by manual selection, or automatically, in reaction to the pressure exerted on a supporting surface by the body of a human being or animal. The areas of the body that exert the most intense pressure against the surface (the areas that support weight) are identified by the naked eye or by measuring the pressure, and the portions of the surface contacted by the weight-bearing areas are cooled by activating a or more contiguous cooling zones. Cooling applied to a portion of the support surface also cools a weight bearing area that is applying pressure to the portion.

The zones can be selected manually by the person in charge of the patient's care. Optionally, some means for sensing the pressure can be provided to thereby detect the contact pressure existing between the support surface and the skin of the body being supported. When a limit contact pressure is exceeded, the detection means activates another medium, which automatically initiates cooling through one or more of the adjacent zones, of portions of the surface on which weight bearing areas are being supported.

More specifically, our invention is an apparatus that concentrates cooling applied to a supported body of a human being or of an animal, selectively activating cooling zones arranged in alignment with respect to those areas of the body that are bearing weight.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a person in a supine position and a graphic tracing showing the pressure exerted on the body parts of a person carrying weight, by a surface that supports the body.

Figure 2 is a plan view from above, partially schematic, of a preferred embodiment of the invention, in which the subdivision of a cooling layer into a plurality of zones is shown.

Figures 3 and 4 are longitudinal, partly schematic, sectional illustrations of the preferred embodiment of Figure 2.

Figure 5 is a schematic diagram showing the control of the cooling zones of the preferred embodiment illustrated in Figure 2.

Figures 6 and 7 are longitudinal, partly schematic, sectional illustrations of a variant of the first preferred embodiment.

Figure 8 is a longitudinal section, partly schematic, of a first alternative embodiment of the invention.

Figure 9 is a longitudinal cross section, partly schematic, of the first alternative embodiment in Section 9-9 of Figure 8.

Figure 10 is an enlargement of a portion of Figure 9.

Figure 11 is a plan view from the top of a second alternative embodiment of the invention.

Figure 12 is a longitudinal sectional view, partly schematic, taken along section 12-12 of Figure 11.

Figure 13 is a partially schematic sectional view taken along section 13-13 of the Figure DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the figures illustrating this invention, and in which like parts are designated with similar reference numbers in all the drawings, Figure 1 shows a person in supine position 12 resting on a surface 14; that is, that it is supported by it. Directly below the surface 14 there is a graphic trace 15 representing the pressure measured at the surface 14. The pressure is exerted by the portions of the body that bear weight and has its maximum magnitude in those areas where the body 12 contacts the the surface 14. It should be noted in particular that the different pressure profiles of the back of the head are shown in number 16, the upper part of the back in 18, the buttocks in 20, the calves in the 21, and heels on 22. (The contribution of the elbows is not shown). These are the areas of the body that support much of the person's weight, and are referred to as "weight-bearing areas." Of course, if the person in supine position 12 is raised in a bed, the weight-bearing areas, including buttocks and heels, are the ones that are most at risk of pressure injuries.

In its structure and operation the invention provides a localized cooling to alleviate the effects of the pressure acting between a support surface and the body areas of a human or animal being weight bearing. A localized cooling is provided by selectively operating zones of a multizonal cooling layer to cool one or more portions of the support surface where the body areas of a supported human or animal body supporting weight are supported, which subsequently cools the areas that support weight. This principle takes shape, preferably, in an apparatus illustrated by the partially schematic cut-away drawings of Figures 2-4.

As illustrated in Figures 2-4, the invention includes a cooling layer 30 that is divided into several zones, such as zone 31. Figure 2 shows a plan view from the top of cooling layer 30 with seven areas, one of which is the area marked by the reference numeral 31. Preferably, each of the zones consists of a separate chamber of a flexible water mattress through which cold water can be circulated, below 37 ° C (which is the normal temperature of the human body), independently of any other camera. Preferably, the chambers are rectangular in shape and each of them has one or more serpentine fluid channels formed by overlapping punched stamps (such as seal 32) that locally bond two sheets of material. Each chamber has its own inlet hose and its own outlet hose, respectively, the inlet hoses of all the chambers being indicated by the reference numeral 34, and the outlet hoses by the reference numeral 36.

In order to understand how each of the zones of the cooling layer 30 of the preferred embodiment works, it is necessary to refer especially to the zone 31. The chamber comprising the zone 31 receives a respective flow of cold water through the water. the inlet hose 34a and return the respective flow of cold water through the outlet hose 36a. With this structure, a cold water inlet flow 37a is conducted to the zone 31 through the inlet hose 34a. Upon entering the chamber of zone 31, the inflow is divided between the serpentine channels as indicated in 37b. The cold water flows through the chamber of the zone 31 and leaves, as indicated at 37c, towards the outlet hose 36a.

Although the term "water mattress" is being used in the description of this preferred embodiment, it should be understood that different fluids can be circulated through a corresponding structure with a similar cooling effect. Such fluids may include, for example, glycol-water mixtures, alcohol-water mixtures, air, etc.

In the preferred embodiment of Figures 2-4, the water mattress incorporating the cooling layer 30 is divided into rectangular zones, the longitudinal axis of each zone being oriented substantially transverse to the longitudinal axis A-A of a human body. In a mattress incorporating this embodiment of the cooling layer 30, each chamber should preferably be in its transverse dimension, at least half the width of the mattress. This allows the cooling of a transverse segment of the body having a high pressure contact with a bearing surface 40, without cooling the adjacent, normally perfused, body contact areas, which could result in general hypothermia and discomfort. However, it is not intended that this limit the subdivision of the cooling layer 30 into a parallel set of elongated rectangular zones; in fact, the zones can have a square or rectangular shape and be distributed within the cooling layer by means of a chessboard design.

In the preferred embodiment illustrated in Figures 2-4, the flow of fluid to each chamber is controlled independently. In this regard, the fluid flow can be controlled manually by the person in charge of it, or each chamber can have its corresponding pressure sensor to automatically start the flow of the fluid cooled to and through that chamber, when the pressure applied by the body supported against the support surface 40 exceeds a previously selected limit value. The preferred pressure sensing means of the embodiment illustrated in Figures 2-4 consists of a piezoresistant, pressure sensitive film, which is incorporated into a structure or element that includes the support surface or is contiguous thereto. In the form of the preferred embodiment that includes the oblong rectangular areas, such as zone 31, the piezoresistant and pressure sensitive film will have formed therein piezoresistant and pressure sensitive individual areas, respectively, which are illustrated on the dotted line of Figure 2. Reference numeral 39 corresponds to a piezoresistant area and sensitive to pressure such. Each of these areas has its respective pressure sensor. As illustrated in Figures 2-4, the pressure sensor 39 has a rectangular configuration that is aligned, in plan, with the zone 31. As best seen in Figures 3 and 4, pressure sensor house is aligned , as described above, with respect to a respective zone. Figure 3 shows a preferred structure of a mattress or cushion incorporating a support layer 32, which preferably comprises a compressible material or structure in the form of a mattress.

In the structure illustrated in Figure 3, the cooling layer 30 is formed by a water mattress which can have a construction similar to that of normal water mattresses, which are well known in the medical field and can be obtained, for example, at the Cincinnati Sub Zero Products company, Cincinnati, Ohio, or at Gaymar Industries, Orchard Park, New York, with the extra feature of having several independent chambers, preferably of transverse fluid. Generally these mattresses are made with two sheets of flexible polyethylene or polyvinyl film, thermoformed in a labyrinth of fluid channels, and then heat sealed together. With an external pump with cooling capacity the water is circulated by such mattress. The circulating cooling water causes the water mattress to function as a primary heat sink. Finally, the heat dissipates to a secondary heat sink, which is usually room air. To connect the primary and secondary heat sink, in addition to the pump, a reservoir and a cooling medium may be required, all of which are of the conventional type, so they are not shown individually in the figures. The cooling means can be compression refrigeration, cooling thermoelectric cooling, radiators, with ice, phase variation materials or any other type suitable to maintain the circulating fluid at a temperature that is below the normal body temperature human, which is 37 ° C.

As shown in Figure 3, the cooling layer is located on the mattress or mat just below the surface 40 and supports at least a portion of the body of a human or animal. Optionally, in the structure including the surface 40 the pressure sensors 39 can also be integrated, so that the pressure sensors are located between the surface 40 and the cooling layer 30. This is not intended to that a structure in which the sensors 39 are disposed on the surface 40 or in it can not be used. The sensors 39 can also be placed in the cooling layer 30.

In Figure 4, the shaded area 44 represents a portion of the human body supported on the surface 40. Assuming that the length of the arrows 46, 47 and 48 represent the pressure exerted against the surface 40 by a portion of the body that is supporting weight , such as the buttocks, and assuming, furthermore, that the pressure magnitudes represented by the lengths of those arrows exceed the magnitudes represented by the arrows 50 and 51, in the preferred embodiment the cold fluid is supplied to the zones 31 which are aligned with the portion of the body that is supporting weight indicated by the pressure profile 46, 47, 48.

In Figure 5 the means for selectively operating one or more of the zones of the plurality of zones existing in the cooling layer 30 to cool a portion of the surface 40 being pressed by an area of the body which is supporting weight represented by the shaded area 44. In Figure 5, the set of pressure sensors 39, including the pressure sensor! and the pressure sensor-) provide an indication of the pressure exerted by the body of a human being or an animal against the surface 40. Preferably, the pressure sensors supply voltage signals that are compared against a limit voltage. Vh by a zone selector 50. The zone selector may include, for example, substantially conventional limit circuits for processing the signals from the pressure sensors. For each pressure sensor that supplies a signal having a magnitude of voltage exceeding Vth, the zone selector 50 supplies a signal that sends cold fluid, provided by a cold fluid source., through means 53, which may consist, for example, of a collector / distributor. The fluid flow in each zone can be controlled by a zone controller, such as zone controllers 55, and each of them includes, for example, a valve mechanism that initiates the flow of cold fluid into the related zone. This allows a separate flow of cold fluid to be supplied, respectively, to one or more zones of the cooling layer 30.

Alternatively, the fluid flow in each zone can be controlled manually by the person in charge of it. In this regard, each zone of the cooling layer would have a known location with respect to the support surface. Through visual inspection, the person in charge would detect the location of the weight bearing areas that could be at risk of suffering a pressure injury, and activate the valve or valves necessary to initiate the flow of cold fluid to the corresponding areas, thereby selectively cool specific areas of the skin that were at risk. The manual activation of the zones is illustrated in Figure 5 by the MANUAL CONTROL input in each zone controller 55.

A beneficial result achieved by the invention as described so far with reference to the preferred embodiment, avoids general hypothermia and discomfort by cooling only those areas of the human body or that of an animal having high pressure contact with the surface of the body. support 40. Since many bedridden patients who are at risk of suffering a pressure injury can not move or turn in bed by themselves, automatic pressure detection may not be necessary, making manual control preferable. However, with the spontaneous movement of the patient, an automatic control is incorporated into this invention as illustrated in Figure 5.

Figures 6 and 7 show a variant of the preferred embodiment illustrated in Figures 3 and 4, by the addition of a relatively thin layer 60 of thermally conductive material disposed between the cooling layer 30 and the surface 40. The layer 60 is optional , and preferably includes a mat of thermally conductive material that "matches" the uneven upper surface that is a product of the thermoformed channels of the water mattress incorporating the cooling layer 30. Preferably, the thermally conductive material of the layer 60 can include, for example, a polymer gel, water or other fluid. The sensors 39 may be disposed on the thermally conductive layer 60, or therein, or below it.

We will now refer to Figures 8-10, which illustrate a first alternative embodiment of the invention. The first alternative embodiment of the invention is represented by an apparatus 80 having an apparatus 82 supporting a patient, which, in the figures, is elongated in order to provide a hammock-like structure supporting a person 81 in the supine position. It should be understood that it is not intended that the first alternative embodiment be limited solely to supporting a fully extended or reclined person, but that anything less than the entirety of a human body or an animal may also be applied. A cooling layer in the form of a collection / distribution overpressure chamber structure 84 is arranged below the support structure 82, which is divided into zones in order to provide selective cooling according to the principles mentioned above in the presentation of the embodiment preferred The support apparatus 82 includes a frame 85 on which the apparatus rests, for example, on the ground or other supporting surface, plus a mesh 86 that extends between elongated parallel anchor tubes 88, and is anchored thereto. . The collection / distribution overpressure chamber structure 84 is supported on a base 89 and includes two parallel longitudinal air overpressure chambers 90, and a plurality of air overpressure chambers 93 disposed transversely to the air overpressure chambers. longitudinal elongated 90. The longitudinal air overpressure chambers 90 communicate with the transverse air overpressure chambers 93 to convey cold air. A longitudinal air plenum 90 includes means for receiving a stream of cold air from a pressurized cold air source including air cooling means 96 and a fan 97.

Each of the transverse air overpressure chambers 93 is disposed below its respective portion of the mesh 86. Clearly, the mesh 86 includes a supporting surface corresponding to the support surface 40 discussed above, while the transverse air plenums 93 consist of a plurality of zones that are selectively controlled to cool elongated cross portions of the mesh 86. An air jet groove valve 94 provides selective control of each air plenum chamber, and has a first normally closed position covering an air jet slot 95, and a second open position opening its related air jet slot 95.

As illustrated in the partially schematic sectional drawing of Figure 9, the flow of pressurized air travels through the longitudinal air plenums 90 and through all of the transverse air plenums 93, including the chamber of transverse air overpressure 93 shown in Figure 9. In Figure 9, the transverse air overpressure chamber 93 is positioned under the buttocks of the person in supine position 81, and has been operated to have its valve open. of air jet slot 94 in order to send a flow of cold air upwards towards the 86 mesh. The cold air flow cools the 86 mesh and the gluteal area supporting the weight of the person 81 which presses on 86 mesh in the transverse location. The air introduced by an air jet slot 95 exits below the side and the ends of the support apparatus 82, or through the mesh 86 (if the mesh is porous).

Figure 10 is an amplified illustration of a portion of the first alternative embodiment enclosed in the circle marked by the number 100 in Figure 9. The illustration is a mirror image of the corresponding section of the right hand side of Figure 9. As illustrated in Figure 10, the mesh 86 is anchored to each of the elongate parallel anchoring tubes 88 by a mesh anchor flange 104 which is conventionally attached to the tube 88 and which catches the mesh 86 between itself and the tube 88. Along the circumferential section of the tube 88 that is not covered by the flange 104, a pressure transducer 102 is disposed between the mesh 86 and the tube 88. As shown in the reference of Figure 8, there is a plurality of pressure transducers 102 distributed along the anchor tubes 88, such that each transverse air overpressure chamber 93 is respectively aligned with one of the several transductore s of pressure 102. Although not shown in Figures 108-110, pressure transducers may be arranged in this manner or in any other suitable manner along one of the anchor tubes 88 or both.

In the first alternative embodiment illustrated in Figures 8-10, patient 81 is supported by a mesh made, preferably, of a woven fabric of synthetic, natural, metal or glass fibers, or a combination thereof. Preferably, but not necessarily, it has a non-tight interlacing so that air can pass through it. The transverse cooling zones are defined by the transverse air plenums 93, which preferably are spaced periodically along the longitudinal dimension of the patient which is supine below the mesh 86. Alternatively, the air overpressure chambers 93 may be arranged to form cooling zones with another shape, such as, for example, "chessboard". The air flow sent through the structure of the air collection / distribution overpressure chamber 84 can be cold air or air at room temperature. Of course the air that blows in the 86 mesh, or through it, cools the adjacent skin of the person 81 who is in the supine position. Each air jet slot valve that actively selects an overpressure chamber can consist, for example, of a simple gate hinged longitudinally on the outer surface of the transverse air overpressure chamber 93 so that it opens and closes over a slot of corresponding air jet. The installation of other types of air valves may be feasible.

The schematic layout of Figure 5 incorporates an architecture suitable for selectively controlling the air jet slot valves 94 of the first alternative embodiment. In this regard, each zone controller may consist, for example, of an activator, such as an electromechanical solenoid, which mechanically opens and closes the valve, whereby air is selectively supplied so that it blows over a portion of the valve. the 86 mesh As with the preferred embodiment, the area to be cooled can be manually controlled by the person in charge by manually activating a corresponding air jet slot valve 94. Optionally, the sensor / selector combination The zone illustrated in Figure 5 can be implemented using the structural elements illustrated in Figures 8-10. In this regard, each of the sensors 102 may contain a piezoresistant pressure sensor.

Now we will refer to Figures 11, 12 and 13, in which a second alternative embodiment of the invention is illustrated. In these figures, a plurality of rectangular inflatable air chambers are arranged by sequential arrangement. In this arrangement, each air chamber is oriented in parallel with at least one adjacent air chamber, and transversely to the longitudinal axis AA of the person in supine position 81. Each of the air chamber 110 has an upper surface 111 , and the upper surfaces 111 of the air chambers 110 collectively form the supporting surface of the person in the supine position 81. Alternatively, the surface may contain a thin layer of thermally conductive material adjacent to the upper surfaces of the chamber. of air. Preferably, the rectangular air chambers 110 are supported on a five-sided rectangular open frame 112. The air chambers 110 are made of flexible woven materials such as synthetic fabrics, which may or may not be coated with a polymeric material or attached to a polymer film.

A first elongated plenum chamber 115 covering the entire length of the frame 112 receives a cold air flow of 96, 97, and transports it to the air chambers 110, each of which covers almost the entire width of the frame 112 The first overpressure chamber 115 feeds each air chamber through an air jet slot 117. Each air jet slot 117 is controlled by an air jet slot valve 116 having an open position, allowing so that cold air flows into and circulates through the air chamber 110, and has a closed position that prevents cold air from flowing into the air chamber 110. Control of the air jet slot valves 116 it may be as set forth above with reference to the first and second preferred alternative embodiments. In a related manner, the air jet slot valves 116 are preferably operated with a solenoid control provided by manually operated or automatically controlled means. In this last aspect, a set of pressure sensors constituted by a thin film in a single sheet can be provided through the upper surfaces 111, in such a way that a sensor is aligned with each of the air chambers 110 to have an automatic control as illustrated above in relation to Figure 5.

Each air chamber includes means for discharging air in a controlled manner, to allow a continuous circulation of air within and through the chamber 110. The means for discharging air may include a migration through a controlled porosity of the fabric, or through ventilation holes or an air return duct.

The fan 120 and the heating element 121 generate an air flow at a temperature higher than the temperature of the cold air flow sent through the first overpressure chamber 115. A second and only elongated suppression chamber 125 receives such a flow with Higher temperature of fan 120 and heating element 121, and leads it to the air chambers 110. The second overpressure chamber 125 is supplied to heat, if necessary, and to keep the air chambers that are not receiving cold air inflated. The second overpressure chamber 125 feeds each air chamber through an air jet slot 127 which is controlled by an air jet slot valve 126 having an open position, thus allowing the higher temperature air flow into the air chamber 110 and circulate therethrough, and has a closed position which prevents the higher temperature air from flowing into the air chamber 110. The control of the air jet slot valves 126 can be controlled. performing as described above with reference to the first and second preferred alternative embodiments. In a related manner, the air jet slot valves 126 are preferably driven with solenoids, and the solenoid control is provided by manual or automatically controlled means. With reference to this last aspect, the set of thin film pressure sensors can be processed by a voltage limit Vth #, with a pressure sensor that generates a voltage above its limit voltage in reaction to the pressure it is supporting. weight, which will automatically close the air jet slot valve 126 and open the air jet slot valve 116, thereby allowing cold air to flow into and through the air chamber. With respect to pressures that do not cause the generation of a voltage that exceeds the limit voltage, the air jet slot valves 116 would be closed and the air valves 126 would open. This reciprocal operation will keep all the air chambers in a predetermined state of inflation or distension as a reaction to the air that is circulating, thereby ensuring a uniform support of the body 81 through the surface on which the body is being supported.Of course, many modifications and variants and many alternative embodiments to this invention can be made without departing from the spirit and scope thereof, which is limited only by the claims set forth below.

Claims (21)

1. An apparatus to support the body of a human being or an animal, while selectively cooling the areas of the body that support weight, which consists of: a cooling layer having a plurality of zones; a surface arranged on the cooling layer, each zone of the cooling layer being arranged so as to cool a respective portion of the surface; Y means for selectively operating one or more zones of the plurality of zones to cool a portion of the surface that is being pressed by a weight-bearing area of the body.

2. The apparatus of Claim 1, further including a support structure disposed against the cooling layer, so that the cooling layer is located between the support structure and the surface.

3. The apparatus of Claim 1, further including means for detecting a location where the body is applying pressure to the surface, the means for selectively operating the means for detecting and reacting to a pressure indication being coupled. to operate at least one area.

4. The apparatus of Claim 3, wherein the cooling layer has a structure for circulating a cold fluid, the structure being divided into a plurality of separate chambers, and each chamber conducts a respective flow of the cold fluid.

5. The apparatus of Claim 4, wherein the structure is a water mattress.

6. The apparatus of Claim 5, wherein each chamber is generally rectangular.

7. The apparatus of Claim 4, wherein the means for indicating consists of a sensor layer disposed against the surface, the sensor layer including a plurality of pressure sensors, each pressure sensor being substantially aligned with a respective chamber of the plurality of cameras. .

8. The apparatus of Claim 7, wherein the sensor layer includes a piezoresistant film.

9. The apparatus of Claim 4, wherein the circulating fluid is cold water.

10. The apparatus of Claim 4, further including a support structure disposed against the cooling layer, so that the cooling layer is located between the support structure and the surface.

11. The apparatus of Claim 1, wherein the surface consists of a sheet of flexible material, the apparatus including means for arranging the sheet of flexible material on the cooling layer.

12. The apparatus of Claim 11, wherein the cooling layer includes an overpressure chamber structure for circulating cold air.

13. The apparatus of Claim 12, wherein the structure of the plenum chamber includes a plurality of air plenums, each positioned relative to a respective portion of the sheet of flexible material, including an air jet means for sending a flow of cold air towards the respective portion of the sheet of flexible material.

14. The apparatus of Claim 13, further including means for selectively operating the air jet orifices of a plurality of air plenums, opening and closing the air jet orifices.

15. The apparatus of Claim 14, further including a plurality of pressure sensors arranged to detect the pressure exerted against the sheet of flexible material, the selective operating means being connected to a plurality of pressure sensors and reacting to a pressure detected by a pressure sensor and acting against the respective portion of the sheet of flexible material opening an air jet orifice of an air plenum positioned with respect to the respective portion.

16. The apparatus of Claim 12, wherein: the sheet of flexible material and the means for arranging shape a hammock-shaped structure; Y The overpressure chamber structure includes at least one longitudinal air plenum chamber and a plurality of transverse air plenums that are in communication with at least one longitudinal air plenum chamber.

17. The apparatus of Claim 1, wherein the cooling layer comprises a plurality of air chambers and an overpressure chamber communicating with the plurality of air chambers to conduct a flow of cold air to the plurality of air chambers. air, and means for selective operation include a plurality of air jet orifice valves, each arranged to allow the flow of cold air in a respective air chamber or to block the flow of cold air into the respective air chamber. air chamber.

18. The apparatus of Claim 17, wherein the plurality of air chambers is arranged in a sequence in which each air chamber is contiguous with at least one of the other air chambers.

19. The apparatus of Claim 18, wherein each air chamber of the plurality of air chambers has a substantially rectangular shape and includes an upper surface, the surface including upper surfaces of the plurality of air chambers.

20. The apparatus of Claim 17, wherein the overpressure chamber is a first plenum chamber and the plurality of air jet orifice valves is a first plurality of air jet orifice valves, the apparatus further including a second overpressure chamber communicating with the plurality of air chambers for sending air flow to a temperature higher than the temperature of the cold air flow, and a second plurality of air jet orifice valves, each being disposed to allow the flow of air towards a respective air chamber or to block the flow of air towards the respective air chamber.

21. A method for supporting a body on an apparatus that includes a cooling layer with a plurality of zones, while simultaneously cooling, selectively, areas of the body, and consisting of the following steps: dispose a surface on the cooling layer; applying a pressure against the surface by arranging at least a portion of the body on the surface; detect a place on the surface on which the pressure is being applied; Y operate one or more zones to cool the place. SUPPORT DEVICE WITH A PLURALITY OF THERMAL ZONES THAT PROVIDE LOCALIZED COOLING SUMMARY OF THE INVENTION An apparatus for supporting the body of a human being or an animal, while selectively cooling areas of the body that support weight, in order to avoid or reduce the damage that can be caused by ischemia, which includes a split cooling layer in a plurality of zones, and a surface disposed on the cooling layer to support the body. Each zone of the cooling layer is arranged so as to cool a respective portion of the surface. Means are provided for selectively operating one or more zones of the plurality of zones to cool a portion of the surface that is being pressed by a weight bearing surface of the body being supported.