Abstract:
The present invention relates to a system and method for sacral and trochanteric support and off-loading. The system provides a ultra low pressure plenum and a positioner. The patient body size and size and corresponding surface area of the positioner control the amount of gas which is displaced evenly against the walls of the ultra low pressure plenum to allow the combination of the ultra low pressure plenum and the positioner to slightly lift a patient from a bed surface, thereby offloading the sacrum and trochanter. The positioner can be an ultra low pressure bladder.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 13/493,582 filed Jun. 11, 2012, which claims the benefit of U.S. Provisional Patent Application No. 61/614,791 filed Mar. 23, 2012 and U.S. Provisional Patent Application No. 61/495,089 filed on Jun. 9, 2011, the entireties of which applications are hereby incorporated by reference into this application. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a patient support which can be used in a bed or flat surface and in particular to a system and method for sacral and trochanteric support which can be used for turning and repositioning of a patient in a bed or on a flat surface. 
         [0004]    2. Description of Related Art 
         [0005]    Hospital bed and other patient static air and dynamic air supports are known. Typically, such patient supports are used to provide a support surface for patients or other individuals for treatment, recuperation, or rest and prevention of skin breakdown. 
         [0006]    It is desirable to provide an improved support for sacral and trochanteric off-loading and other bony prominences such as scapula, ishial tuberocities. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention relates to a system and method for sacral and trochanteric support and off-loading. It is optimal to barely elevate the sacrum and trochanter from the surface of the bed. The system provides a ultra low pressure plenum and a positioner. The ultra low pressure plenum can include one or more air chambers. The air chamber is filled at a predetermined low pressure for distributing pressure along the length of the ultra low pressure plenum, but not providing significant elevation of a received body part by itself. 
         [0008]    A cover can be received over the ultra low plenum. The cover can include a retaining member for receiving the positioner. The cover can include a temperature regulating material for keeping the received body part in an optimal range of skin temperature to keep comfortable longer. In one embodiment, a phase change material can be used for adjusting the temperature of the system to adapt to temperature changes of the body. 
         [0009]    The positioner includes a bladder preferably filled with a fluidized particulate material with sufficient size and shape to displace an amount of air in the support to offload pressure being from a received body part, such as, but not limited to, the bony prominences of the sacrum and trochanter including and any vulnerable bony prominences. The positioner can be placed at a lower position of the ultra low pressure plenum to displace air from the lower position of the ultra low pressure plenum to an upper position of the ultra low pressure plenum. The surface area of the positioner provides greater positive air displacement than would occur from the body part of the patient by itself. In one embodiment, the positioner can have a greater width than the patient. 
         [0010]    Alternatively, the positioner can be an ultra low pressure bladder. The positioner has the advantages of increasing the pneumatic assist when turning. The positioner also stabilizes the body of a user to prevent the body from twisting and attenuates the interface pressure after the legs are placed on the lower position of the ultra low pressure plenum. The positioner displaces air in lower position of the ultra low pressure plenum to an upper position of the ultra low pressure plenum and to places of the ultra low pressure plenum that have less resistance, such as the lumbar spine and the sides of the ultra low pressure plenum that are not bearing weight from a body received on the ultra low pressure plenum. The positioner provides three dimensional movement and dramatically reduces shear forces on the sacrum. 
         [0011]    In one embodiment, the ultra low pressure plenum includes a lower bladder section having a smaller width dimension than an upper bladder section. The air chambers of the lower bladder section and the upper bladder section being in air communication with one another. Air is communicated within the upper bladder section and lower bladder section through air displacement. The patient body size and size and corresponding surface area of the positioner control the amount of air which is displaced evenly against the walls of the ultra low pressure plenum to allow the combination of the ultra low pressure plenum and the positioner to slightly lift a patient from a bed surface, thereby offloading the sacrum and trochanter. 
         [0012]    Preferably, the positioner has little or no flow characteristics unless an outside force is applied other than gravity. The positioner can displace and contour three dimensionally as though it was fluid while not having flow characteristics that would result in migration of the medium under the force of gravity. The positioner can provide three dimensional contouring. The positioner can be shaped as a pad. 
         [0013]    The combination of the ultra low pressure plenum and positioner, including a fluidized medium, creates sufficient support of the received body part while responding to normal patient movement. The positioner can be placed adjacent the iliac crest and scapula along the spine to displace enough air to off load the greater trochanter that is currently bearing the weight of the body and should be placed proximal in a way to displace the air of the lower section of the bladder to offload the sacrum. 
         [0014]    The ultra low pressure plenum can be low profile. In one embodiment, the system including the ultra low pressure plenum can be positioned underneath the sheets of bed, such as a hospital bed. Alternatively, the system including the ultra low pressure plenum can be placed above the sheets for aiding in patient turning and repositioning. 
         [0015]    In one embodiment, the positioner can be positioned at one of outer walls of the support to push air away from the outer wall, thereby aiding in turning of a patient. 
         [0016]    In one embodiment, a lower surface of the ultra low pressure plenum is formed of a material having a low coefficient of friction to allow the ultra low pressure plenum to be used to move a patient on a surface, such as a hospital bed. The upper surface of the ultra low pressure plenum and/or the lower surface of the positioner can be formed of a material having a high coefficient of friction to retain the positioner in place and prevent unwanted movement of the positioner while in use over the support. For example, the material can be a non-skid material. Gripping handles can be provided on either edge of the ultra low pressure plenum to aid in movement of the ultra low pressure plenum when a patient supported by the ultra low pressure plenum. In this embodiment, the gripping handles can be placed over the sheet and unweighted to allow the patient to be moved for turning and repositioning of the patient. In one embodiment, the gripping handles are holes in the cover. In an alternative embodiment, the gripping handles are placed under the sheet and have a high coefficient of friction to prevent movement of the ultra low pressure plenum. 
         [0017]    In one embodiment, the system includes a three layer construction in which the layers are sealed to one another along the outside edges. The system provides a capacity for low air loss. Each of the layers form a plenum. Any of the layers can be perforated. A valve can be inserted through the appropriate layer for connection to an air flow. The other layers can be static plenums. 
         [0018]    In one embodiment, the system includes a four layer construction in which the layers are sealed to one another along the outside edges. The system provides a first plenum formed between a top layer and a first intermediate layer. The first plenum can be fixed air chamber or a chamber providing low air loss. A second plenum is formed between a second intermediate layer and a bottom layer. The second plenum can provided alternating pressure. One or more valves can extend from the second plenum for attachment to a pneumatic device. The pneumatic device can be adjusted to provide alternating pressure for either sequential or intermittent therapies. 
         [0019]    The invention will be more fully described by reference to the following drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIGS. 1A-1C  are a schematic diagrams of a support used in a system for sacral and trochanteric support in accordance with the teachings of the present invention. 
           [0021]      FIG. 2  is a schematic diagram of a positioner used in the system for sacral and trochanteric support. 
           [0022]      FIG. 3  is a schematic diagram of the system including the support and the positioner. 
           [0023]      FIG. 4  is a schematic diagram of the system including the positioner positioned at an outer wall of the support. 
           [0024]      FIG. 5  is a schematic diagram of an alternate embodiment of a system for support of a body part in accordance with the teachings of the present invention which provides low pressure loss. 
           [0025]      FIG. 6  is a schematic diagram of an alternate embodiment of a system support of a body part in accordance with the teachings of the present invention which provides alternating pressure. 
           [0026]      FIG. 7  is a schematic diagram of a support used in an alternate embodiment of a system for sacral and trochanteric support in accordance with the teachings of the present invention. 
           [0027]      FIG. 8  is a front view of a cover placed over the support shown in  FIG. 7 . 
           [0028]      FIG. 9  is a rear view of a cover placed over the support shown in  FIG. 7 . 
           [0029]      FIG. 10  is a rear view of a cover placed over the support shown in  FIG. 7  including an extension of the support placed in a folded condition. 
           [0030]      FIG. 11  is a schematic diagram of the system for sacral and trochanteric support in accordance with the teachings of the present invention when placed on a bed. 
           [0031]      FIG. 12  is a schematic diagram of the system for sacral and trochanteric support in accordance with the teachings of the present invention when placed on a bed and having one side folded to expose handles attached to a rear side of the support. 
           [0032]      FIG. 13  is a schematic diagram of the system for sacral and trochanteric support in accordance with the teachings of the present invention when placed on a bed and including a positioner placed in a retainer of the cover. 
           [0033]      FIG. 14  is a schematic diagram of the system for sacral and trochanteric support in accordance with the teachings of the present invention when placed on a bed and in use by a user. 
           [0034]      FIG. 15  is a schematic diagram of the system for sacral and trochanteric support in accordance with the teachings of the present invention when placed on a bed and in use by a user during folding of an edge towards the user. 
           [0035]      FIG. 16  is a schematic diagram of the system for sacral and trochanteric support in accordance with the teachings of the present invention when placed on a bed and in use by a user during folding of an extension of the cover and support. 
           [0036]      FIG. 17  is a schematic diagram of the system for sacral and trochanteric support in accordance with the teachings of the present invention when placed on a bed and in use by a user during turning of the user. 
           [0037]      FIG. 18  is a schematic diagram of the system for sacral and trochanteric support in accordance with the teachings of the present invention when placed on a bed and in use including use of a positioner to aid in turning. 
           [0038]      FIG. 19  is a schematic diagram of an alternate embodiment of a positioner used in the system for sacral and trochanteric support. 
       
    
    
     DETAILED DESCRIPTION 
       [0039]    Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. 
         [0040]      FIGS. 1-3  illustrate system for support of a body part of a patient turning and repositioning of the patient with simultaneous offloading of the bony prominences  10  in accordance with the teachings of the present invention. Base  11  has ultra low pressure plenum  12  coupled or integral therewith. Ultra low pressure plenum  12  is configured to a shape to fit underneath a patient and support the lower back and/or hips of a patient. For example, ultra low pressure plenum  12  can have a width W of approximately 52 inches, and a height H of about  35  inches. Alternatively, width W can be a width of a bed, such as a hospital bed. Ultra low pressure plenum  12  is formed of upper bladder  14  and lower bladder  16 . Lower bladder  16  has a smaller width dimension than upper bladder  14 . Air pressure within upper bladder  14  and lower bladder  16  is reduced sufficiently for distributing pressure within ultra low pressure plenum  12 , but is not providing support of the received body part by itself. Upper bladder section  14  extends between edges  13   a - 13   d.  Lower bladder section  16  extends between edges  15   a - 15   d.    
         [0041]    Bottom surface  17  of ultra low pressure plenum  12  can be formed of a material having a low coefficient of friction to allow ultra low pressure plenum  12  to be used to move a patient on surface  19  underneath ultra low pressure plenum  12 , such as a hospital bed. A suitable material having a low coefficient of friction is nylon or rip stop nylon material. Upper surface  18  of ultra low pressure plenum  12  can be formed of a material having a high coefficient of friction. A suitable material having a high coefficient of friction is a rubberized or non-skid material. Gripping handles  20  can be provided on either edge  22   a,    22   b  of base  11  to aid in movement of ultra low pressure plenum  12  over surface  19 . Gripping handles  20  can be placed over a sheet of a bed and unweighted to allow the patient to be moved. In an alternative embodiment, gripping handles  20  are placed under the sheet and have a high coefficient of friction to prevent movement of ultra low pressure plenum  12 . 
         [0042]    Positioner  23  can include bladder  24 , as shown in  FIG. 2 . Bladder  24  is filled with fluidized material  25  which can retain its shape after sculpting. The flowability or lubricity of fluidized material  25  can be increased by adding a lubricant or by the removal of air from the interstitial spaces or both. The preferred medium of fluidized material  25  is a particulate material that has been modified in such a way that it acts like a fluid. 
         [0043]    Fluidized material  25  refers to a compound or composition which can be sculpted and retain its shape and has no memory or substantially no memory. The no memory or substantially no memory feature enables bladder  24  to increase in height and maintain support of a body part. Fluidized material  25  is made of a viscosity that will allow it to contour but not collapse under the weight of the body part. 
         [0044]    At sea level, the normal interstitial air pressure would exceed about 760 millibars of mercury. This increases or decreases marginally as altitude varies. Depending on the nature of the particulate fluidized material  25 , the pressure can be lowered below about 500 millibars to about 5 millibars, preferably, 350 millibars to about 5 millibars, while still maintaining the necessary flow characteristics of the product. 
         [0045]    Fluidized material  25  can include compressible and non-compressible beads, such as polyethylene or polystyrene (PS) beads, expanded polyethylene (PE), crosslinked expanded polyethylene (PE), polypropylene (PP) pellets, closed cell foams, microspheres, encapsulated phase changing materials (PCM). The beads can be hard shelled or flexible. In one embodiment, the beads are flexible and air can be evacuated from the beads. In one embodiment, hard beads can be mixed with flexible beads in which air can be evacuated from the flexible beads. In an alternative embodiment, fluidized material  25  can a porous foam substance including pockets of interstitial air. In one embodiment, fluidized material  25  can be a polyurethane foam. The polyurethane foam can be open or closed cell and cut into small shapes such as spheres or blocks. For example, a sphere of polyurethane foam can have a size of 2 inches in diameter. For example, a block of polyurethane foam can be a 1×1×1 inch block. 
         [0046]    Suitable examples of fluidized material  25  can be formed of a mixture of microspheres and lubricant. The microspheres can include hollow or gas-filled structural bubbles (typically of glass or plastic) with an average diameter of less than 200 microns. The composition flows and stresses in response to a deforming pressure exerted on it and the composition ceases to flow and stress when the deforming pressure is terminated. For example, fluidized material  25  can be formed of a product referred to as Floam™. A flowable compound comprising lubricated microspheres, including the compound itself, formulations for making the compound, methods for making the compound, products made from the compound and methods for making products from the compound as defined by U.S. Pat. Nos. 5,421,874, 5,549,743, 5,626,657, 6,020,055, 6,197,099 and 8,175,585, each of which is hereby incorporated by reference into this application. Bladder  24  provides micro-contouring because fluidized material  25  can respond three-dimensionally. Alternatively, bladder  24  is formed of any contouring medium, such as foam or gel which is sufficient to displace air within ultra low pressure plenum  12 . 
         [0047]    For example, bladder  24  can be formed of a flexible plastic, such as urethane. Upon removal of gas from fluidized material  25 , bladder  24  flows concurrent with the flow of fluidized material  25  such that bladder  24  moves with movement of fluidized material  25 . For example, the gas can be air, helium, hydrogen or nitrogen. Optionally, gas can communicate throughout the whole bladder for allowing maximum contouring and functional displacement of both the gas and the fluidized chamber thereby providing maximum contouring to a desired body part. 
         [0048]    Bladder  24  is preferably filled with fluidized particulate material  25  with sufficient size and shape to displace an amount of gas in ultra low pressure plenum  12  to offload pressure from the received body part, such as the bony prominences of the sacrum and trochanter. Lower surface  26  of positioner  23  can be formed of a high friction material for preventing movement of positioner  23  over ultra low pressure plenum  12 . 
         [0049]    For example, the pressure in ultra low pressure plenum  12  can be below 20 mm of water. It will be appreciated that all equivalents such as mm Hg and PSI can be used for measuring the pressure within ultra low pressure plenum  12 . 
         [0050]    The pressure within ultra low pressure plenum  12  can be below about 20 mm of water if no positioner  23  is used or if an area of less than about 30% of ultra low pressure plenum  12  is covered by positioner  23 . The pressure within ultra low pressure plenum  12  can be below about 10 mm of water if an area of between about 30% to about 60% of ultra low pressure plenum  12  is covered by positioner  23 . The pressure within ultra low pressure plenum  12  can be below about 5 mm of water if an area of greater than about 60% of ultra low pressure plenum  12  is covered by positioner  23 . 
         [0051]    Positioner  23  can be placed over lower bladder  16  of ultra low pressure plenum  12  to displace gas from lower bladder  16  to upper bladder  14  in the direction of arrows A 1 , as shown in  FIG. 3 . When a patient is recumbent on ultra low pressure plenum  12  with their sacrum received on positioner  23 , gas will be displaced in upper bladder  14  towards outer edges  13   a  for providing support adjacent to edges  13   b  and  13   d  thereby providing support of edges  13   b  and  13   d  of upper bladder  14  of the patient within edges  13   b  and  13   d  and lifting a patient from surface  11  and offloading the sacrum and trochanter. 
         [0052]    In one embodiment, positioner  23  can be positioned at one of edges  13   b  and  13   d  to push air away from respective edges  13   b  and  13   d  thereby aiding in turning of a patient towards the opposite edge, as shown in  FIG. 4 . For example, if the patient is to be turned towards edge  13   d,  positioner  23  can be placed at edge  13   b  for displacing gas behind the patient to towards edge  13   b  of upper bladder  14 , thereby pneumatically assisting in turning of the patient to face edge  13   d.    
         [0053]    System  10  including ultra low pressure plenum  12  is functional whether positioner  23  is placed on top of ultra low pressure plenum  12  or beneath ultra low pressure plenum  12 . 
         [0054]      FIG. 5  illustrates an alternate embodiment of support of a body part  100 . System  100  has a three layer construction. Top layer  102 , intermediate layer  103  and bottom layer  104  are sealed to one another along outside edge  105 . For example top layer  102  and bottom layer  104  can be formed of urethane. 
         [0055]    Plenum  110  formed between top layer  102  and intermediate layer  103  can include dynamic air. Air  115  is pumped into plenum  110  through valve  111  by pump  112 . Air  115  is pumped beneath top layer  102 . Top layer  102  is perforated with apertures  118 . Plenum  110  provides a dynamic amount of air to system  100  for adjusting the amount of air in plenum  114  and providing low air loss. 
         [0056]    Plenum  114  formed between bottom layer  104  and intermediate layer  103  can include a fixed amount of static air. Valve  116  can be used to adjust the pressure in plenum  114 . In one embodiment plenum  114  is filled with an ultra low pressure of a pressure of about 20 mm of water to about 5 mm of water or in some cases even lower pressures can be used. 
         [0057]      FIG. 6  illustrates an alternate embodiment of support of a body part  200 . System  200  has a three layer construction. Top layer  202 , intermediate layer  204 , and bottom layer  206  are sealed to one another along outside edge  208  for sealing each adjacent layer to one another. For example top layer  202 , intermediate layer  204  and bottom layer  206  can be formed of urethane. 
         [0058]    Plenum  210  is formed between sealed top layer  202  and intermediate layer  204 . Plenum  210  can be formed as an alternating pressure pad. Air  215  is pumped into plenum  210  by pneumatic pump device  218 . Pneumatic pump device  218  can be operated to pump air in either a sequential or intermittent manner for inflating or deflating plenum  214  to provide respective sequential or intermittent therapies. 
         [0059]    Plenum  214  is formed between sealed bottom layer  206  and intermediate layer  204 . Plenum  214  can include a fixed amount of static air. In one embodiment, plenum  214  is filled with an ultra low pressure of a pressure of less than about 20 mm of water to about 5 mm of water or in some cases even lower pressures can be used. 
         [0060]      FIGS. 7-18  illustrate system for support of a body part of a patient turning and repositioning of the patient with simultaneous offloading of the bony prominences  300  in accordance with the teachings of the present invention. System  300  includes ultra low pressure plenum  312 , as shown in  FIG. 7 . Ultra low pressure plenum  312  is configured to a shape to fit underneath a patient and support the lower back and/or hips of a patient. For example, ultra low pressure plenum  312  can have a width W of approximately  52  inches, and a height H of about  35  inches. Alternatively, width W can be a width of a bed, such as a hospital bed. Ultra low pressure plenum  312  can include upper bladder  314  and extension bladder  315 . Extension bladder  315  extends from upper bladder  314 . Extension bladder  315  and upper bladder  314  can be integral to one another. Air pressure within upper bladder  314  and extension bladder  315  is reduced sufficiently for distributing pressure within ultra low pressure plenum  312 , but is not providing support of the received body part by itself. 
         [0061]    Ultra low pressure plenum  212  can have a pressure of about 20 mm of water through about 5 mm of water in some cases even lower pressures can be used. 
         [0062]    For example, the pressure in ultra low pressure plenum  312  can be below 20 mm of water. It will be appreciated that all equivalents such as mm Hg and PSI can be used for measuring the pressure within ultra low pressure plenum  312 . 
         [0063]    The pressure within ultra low pressure plenum  312  can be below about 20 mm of water if no positioner  23  is used or if an area of less than about 30% of ultra low pressure plenum  212  is covered by positioner  23 . The pressure within ultra low pressure plenum  312  can be below about 10 mm of water if an area of between about 30% to about 60% of ultra low pressure plenum  312  is covered by positioner  23 . The pressure within ultra low pressure plenum  312  can be below about 5 mm of water if an area of greater than about 60% of ultra low pressure plenum  312  is covered by positioner  23 . 
         [0064]    Cover  318  can be placed around ultra low pressure plenum  312 , as shown in  FIGS. 8-10 . Cover  318  can be formed of a material having a low coefficient of friction to allow received ultra low pressure plenum  312  to be used to move a patient on a surface underneath ultra low pressure plenum  312 . A suitable material having a low coefficient of friction is nylon or rip stop nylon material. Extension  325  of cover  318  receives extension bladder  315 . 
         [0065]    Portion  317  on upper surface  327  of extension  325  can be formed of a material having a high coefficient of friction. A suitable material having a high coefficient of friction is a rubberized or non-skid material. Portion  317  can be folded underneath rear surface  319  of upper bladder  314  to prevent movement of ultra low pressure plenum  312 , as shown in  FIG. 10 . Handles  320  can be provided adjacent either edge  322   a,    322   b  of cover  318  to aid in movement of ultra low pressure plenum  312 . Handles  321  can be provided adjacent either edge  324   a,    324   b  of extension  325  of cover  318  to aid in folding of extension  325  underneath rear surface  319 . 
         [0066]      FIGS. 11-18  illustrate use of system for support of a body part of a user turning and repositioning of the user with simultaneous offloading of the bony prominences  300 . In  FIG. 11 , system for support of a body part of a user turning and repositioning of the user with simultaneous offloading of the bony prominences  300  can be placed on bed  330 . System  300  can be moved to different positions on bed  330  using handles  320 , as shown in  FIG. 12 . 
         [0067]    Positioner  23  can be placed within pocket  331  of cover  318  to retain positioner  23 . Positioner  23  can be placed over upper bladder  314  of ultra low pressure plenum  312  to displace gas in the direction of arrow A 2 , as shown in  FIG. 13 . When a user is recumbent on ultra low pressure plenum  312  with their sacrum received on positioner  23 , gas will be displaced in upper bladder  314  in the direction of arrow A 3  towards outer edges  322   a,    322   b  for providing support adjacent to edges  322   a  and  322   b  thereby providing support of the user within edges  322   a  and  322   b  and lifting user  340  from surface  311  of bed  330  and offloading the sacrum and trochanter of user  340 , as shown in  FIG. 14 . Additional positioners  23  can be placed in pocket  331  of cover  118  by lifting edge  322   a  to provide additional displacement of gas within upper bladder  314  as shown in  FIG. 15 . Extension  325  can be folded underneath rear surface  319  of upper bladder  314  to prevent movement of ultra low pressure plenum  312 , as shown in  FIG. 16 . 
         [0068]    In one embodiment, user  340  can be moved or turned by using handles  320 , as shown in  FIG. 17 . In one embodiment, positioner  23  can be positioned behind a side of cover  318  to push gas away from edges  322   a,  thereby aiding in turning of a user towards the opposite edge, as shown in  FIG. 18 . For example, if the patient is to be turned towards edge  322   b,  positioner  23  can be placed at edge  322   a  for displacing gas behind the patient to towards edge  322   b  of upper bladder  314 , thereby pneumatically assisting in turning of the patient to face edge  322   b.    
         [0069]    In one embodiment, positioner  400  can include ultra low pressure bladder  402 , as shown in  FIG. 19 . The pressure within ultra low pressure bladder  402  is a range of less than about 20 mm of water to about 5 mm of water or a range of less than about 10 mm of water to about 5 mm of water. It will be appreciated that all equivalents such as mm Hg and PSI can be used for measuring the pressure within ultra low pressure bladder  402 . In this embodiment, positioner  400  is formed with sufficient size and shape to displace an amount of gas in ultra low pressure bladder  402  to offload pressure from the received body part, such as the bony prominences of the sacrum and trochanter. Lower surface  406  of positioner  400  can be formed of a high friction material for preventing movement of positioner  400  over ultra low pressure plenum  12 . Positioner  400  can be placed on top of ultra low pressure plenum  12  or beneath ultra low pressure plenum  12 . 
         [0070]    Positioner  400  can be placed over lower bladder  16  of ultra low pressure plenum  12  to displace gas from lower bladder  16  to upper bladder  14  in the direction of arrows A 1 , as shown in  FIG. 3 . 
         [0071]    In one embodiment, positioner  23  can be used together with positioner  400 . Positioner  400  can be placed over lower bladder  16  of ultra low pressure plenum  12  positioner  23  can be positioned at one of edges  13   b  and  13   d  to push air away from respective edges  13   b  and  13   d  thereby aiding in turning of a patient towards the opposite edge, similar to positioner  23  as shown in  FIG. 4 . For example, if the patient is to be turned towards edge  13   d,  positioner  23  can be placed at edge  13   b  for displacing gas behind the patient to towards edge  13   b  of upper bladder  14 , thereby pneumatically assisting in turning of the patient to face edge  13   d.    
         [0072]    It is to be understood that the above-described embodiments are illustrative of only a few of the many possible specific embodiments, which can represent applications of the principles of the invention. Numerous and varied other arrangements can be readily devised in accordance with these principles by those skilled in the art without departing from the spirit and scope of the invention.