Abstract:
A back support system that is designed to form the back of a chair. The back support system has a frontal surface on which is mounted several sets of inflatable bladders. The back support system is to be tiltable about a transverse axis toward and away from the user&#39;s back. The back support system also includes bolsters located at each side of the back support system with each bolster to be pivotable toward and away from the lateral edge of the user&#39;s back. The inflatable bladders are positioned to contact the different muscle groups of the back with no inflatable bladder located to apply pressure directly to the spine of a human user.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1.. Field of the Invention  
           [0002]    The field of this invention relates to a back support system and more particularly to a back support system that is designed to be utilized as the back of a chair or in conjunction with the back of a chair.  
           [0003]    2. Description of the Related Art  
           [0004]    The subject matter of the present invention is going to be discussed in relation to a wheelchair. However, it is considered to be within the scope of this invention that the subject invention can be utilized in conjunction with any chair such as a seat in an aircraft, truck, automobile, ergonomic designed chair, work station chair, wheelchair or theater seat.  
           [0005]    Users of wheelchairs are inherently prone to occupying a wheelchair for an extended length of time. For a human body to sit in one particular position over an extended length of time is not only uncomfortable but can cause injuries creating back pain. For reasons to prevent and alleviate any injuries or back pain, the normal technique is to remove the individual from the wheelchair, reconfigure the individual and have the individual to remain free of the wheelchair for a period of time. This is not always a convenient procedure. It would be desirable to design a wheelchair that was constructed in a manner to provide the individual with an orthopedic back support over an extended period of time and also was constructed so as to encourage proper posture and allow an easily varied amount of lumbar support encouraging relief and prevention of back pain and provide positioning to control one&#39;s spine.  
           [0006]    Previous seat design in the past has appeared to be totally inappropriate and unacceptable for the general public. It has been demonstrated that sitting reduced the normal lumbar curve and that prolonged sitting in this posture can produce low back pains and even disc degeneration. Chair design ought to be based on the anatomy of the seated human.  
           [0007]    In the past, there have been attempts at designing a back support that includes some form of support reducing bulging disc pressure while sitting which is accomplished by the cushion of the back support being contoured to follow the natural lines of the human body. For the most part, these prior art devices have been static including some form of a cushioning arrangement and not including any form of adjustability so as to vary the amount of pressure that is being applied to the back of the individual so as to provide an increased level of support and comfort. It has been known to include an inflatable bladder in conjunction with the back of a wheelchair. The design of these prior art bladders when inflated apply direct pressure to discs therefore acerbating back pain. However, the inflating and deflating of these prior art bladders is not easily accomplished and not readily accessible to the user. Therefore, the changing of the inflation and deflation of the bladder is definitely inconvenient, and as a result is accomplished infrequently. Also, these bladders have not been designed to ergonomically fit with the muscular system of the anatomy of a human back.  
         SUMMARY OF THE INVENTION  
         [0008]    A back support system which comprises a rigid base which has an inflatable bladder assembly mounted on the front surface of the rigid base. The inflatable bladder assembly includes several sets of bladders with each set comprising at least two in number of inflatable bladders. Each of the inflatable bladders are spaced from the mid-axis of the base so no force from a bladder will be applied directly to the user&#39;s spine area. Inflation of the bladders is accomplished by means of an air compressor with supplying of the compressed air to each of the bladders to be accomplished by a manually controllable valve assembly located directly adjacent the user.  
           [0009]    Another embodiment of back support system where all of the bladders within each set of bladders is activated simultaneously.  
           [0010]    A further embodiment of back support system of this invention where the operation of the inflation of the bladders is accomplished by the use of a battery.  
           [0011]    A further embodiment of back support system of this invention where there is a set of upper lumbar bladders located in conjunction with the inflatable bladder assembly.  
           [0012]    A still further embodiment of back support system of this invention where there is a middle lumbar set of bladders within the inflatable bladder assembly.  
           [0013]    A still further embodiment of back support system of this invention where there is utilized a lower lumbar bladder as one of the sets of bladders.  
           [0014]    A further embodiment of back support system of this invention where there is incorporated a tilt bladder in conjunction with the rigid base which forms the back of the chair.  
           [0015]    A further embodiment of back support system of this invention where the pad includes inflatable bolsters located at the side edges of the rigid base which is to support the back area of the user.  
           [0016]    A further embodiment of back support system of this invention where the base comprises a pair of rigid plates which are hingedly connected together at one edge and there being a tilt bladder located between these rigid plates so that one plate can be tilted relative to the other plate thereby providing a chair back that can be moved to different tiltable positions.  
           [0017]    A still further embodiment of back support system of this invention utilizes a main section which is to be located across the back of the user. An inflatable bladder assembly is mounted in part on the front surface of the main section with the inflatable bladder assembly including several different sets of bladder. Hingedly connected to each side edge of the main section is a bolster with this connection forming a hinge axis for each bolster. Each hinge axis will permit movement of its respective bolster relative to the main section so as to permit increase and decrease of the lateral support being applied to the user. A series of valves are provided that are manually operable by the user to vary the inflation and deflation of the bladders.  
           [0018]    A still further embodiment of back support system of this invention where there is a rear inflatable bladder mounted on the rear surface of the main section. The main section also includes a transverse axis that permits the main section to pivot. Inflation of the rear inflatable bladder causes the main section to pivot and thereby vary the amount of tilt to the back support.  
           [0019]    A further embodiment of back support system of this invention utilizes a main section to be located across the back of the user and an inflatable bladder assembly mounted on the front of this main section. A rear inflatable bladder is mounted in conjunction with the rear surface of this main section with the main section also including a transverse axis permitting the main section to pivot. Inflation of the rear inflatable bladder causes the main section to pivot to assume various tilted or inclined positions relative to the user. There is also included a series of controls that is manually operable by the user to vary the inflation and deflation of the inflatable bladders mounted on the main section and also the rear inflatable bladder.  
           [0020]    One of the primary objectives of the present invention is to construct a chair back which includes a series of inflatable bladders with no inflatable bladder applying direct pressure to the spine of the user of the chair which assists in controlling alignment of the spine without putting pressure on the spine. Pressure on the spine could cause pain and/or a degenerative disc.  
           [0021]    Another objective of the present invention is to construct a chair back which utilizes a specific series of inflatable bladders that are ergonomically shaped to apply pressure to the different muscle groups that are located within the back of the user.  
           [0022]    Another objective of the present invention is to construct a chair back where the inflatable bladders incorporated therein can be selectively activated and deactivated according to individual comfort.  
           [0023]    Another objective of the present invention is to construct a chair back which will permit a user of the chair to occupy the chair for an extended length of time in a comfortable manner.  
           [0024]    Another objective of the present invention is to construct a chair back which reduces risk of spinal deformity.  
           [0025]    Another objective of the present invention is to construct a back support system that can be easily installed on virtually all models of wheelchairs and can be constructed to accommodate to most all conventional chairs.  
           [0026]    Another objective of the present invention is to construct a back support system for a chair back that provides for a significantly enhanced amount of comfort to the user.  
           [0027]    Another objective of the chair back of the present invention is to provide a back support system that fits to a variety of different individuals.  
           [0028]    Another objective of the chair back of the present invention is to provide a back support system that assists the musculature of the user and to align the spine.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]    For a better understanding of the present invention, reference is to be made to the accompanying drawings. It is to be understood that the present invention is not limited to the precise arrangement shown in the drawings.  
         [0030]    [0030]FIG. 1 shows a schematic view of the back support system of the present invention;  
         [0031]    [0031]FIG. 2 is an internal view of the back support system of the present invention showing the arrangement of the frontal inflatable bladder assembly that is utilized in conjunction with the back support system of the present invention;  
         [0032]    [0032]FIG. 3 is a transverse cross-sectional view through the back support system of the present invention taken along line  3 - 3  of FIG. 1 showing the bolsters in conjunction with the back support system being located in the fully retracted position;  
         [0033]    [0033]FIG. 4 is a cross-sectional view similar to FIG. 3 showing the bolsters in a fully extended position;  
         [0034]    [0034]FIG. 5 is a cross-sectional view similar to FIG. 3 showing the back support system with mounts for connecting to a wheelchair and a housing for enclosing the air compressor and battery source of power;  
         [0035]    [0035]FIG. 6 is a longitudinal cross-sectional view through the back support system of the present invention taken along line  6 - 6  of FIG. 1 showing the back support system in a minimal tilt position; and  
         [0036]    [0036]FIG. 7 is a cross-sectional view similar to FIG. 6 but showing the back support system in the maximum tilted position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0037]    Referring particularly to the drawings, there is shown the back support system  10  of this invention. Back support system  10  includes a control housing  12 . Inside the control housing  12  there is located an electrically operated air compressor  14 . Operation of the air compressor  14  is accomplished by means of a series of batteries  16 . The air compressor  14  supplies compressed air through supply conduit  18 . Electrical power also is supplied by the batteries  16  to electrical conduit  20 . Electrical conduit  20  and supply conduit  18  connect with a valve housing  22 . Contained within the valve housing  22  are a series of valves (not shown) that are capable of supplying pressurized air from the supply conduit  18  to within outlet conduits  24 ,  26 ,  28 ,  30 ,  32  and  34 . Manual pressing of switch  36 , which is mounted on housing  22 , is to control the pressurized air that is being supplied into the outlet conduit  24 . Also mounted on the housing  22  are switches  38 ,  40 ,  42 ,  44 , and  46  which similarly supply pressurized air into their respective conduits  26 ,  28 ,  30 ,  32  and  34 . Switches  36 ,  38 ,  40 ,  42 ,  44  and  46  can each be pressed and released to a hold position which will retain the quantity of pressurized air that has been supplied within their respective bladders. Each of the switches  36 - 46  are also capable of being pressed to a vent position. In that position, the pressurized air contained within its respective outlet conduit  24 - 34  is vented to the ambient. Switches  36 - 46  each connect with the electrically operated valves (not shown) which are mounted within valve housing  22  and are supplied electrical power by conduit  20 .  
         [0038]    Outlet conduit  34  connects with rear inflatable bladder  48 . Outlet conduit  32  connects with right bolster bladder  50 . Outlet conduit  30  connects with left bolster bladder  52 . Outlet conduit  28  connects with upper lumbar bladders  54 ,  56 ,  58  and  60 . Outlet conduit  24  connects with middle lumbar bladders  62 ,  64 ,  66  and  68 . Outlet conduit  26  connects with lower lumbar bladders  70  and  72 .  
         [0039]    The upper lumbar bladders  54  and  60  are each shaped specifically to apply pressure to the deltoid muscle, the infraspinatus muscle, and the terres minor and major muscles. It is to be understood that these muscles in the area of the back overlap. The upper lumbar bladders  56  and  58  are also shaped to apply pressure to the upper portion of the trapezius muscle and also to the serratus posterior superior muscle. The middle lumbar bladders  62  and  68  are shaped to apply pressure to the lower portion of the trapezius muscle, the quadratus lumborum, erector spinae muscle, external abdominal oblique muscle and the internal abdominal oblique muscle. It is to be understood that each of the muscles that are being discussed are on both sides of the spine with it being understood that the spine is in alignment with the mid axis  98 . The middle lumbar bladders  64  and  66  are shaped specifically to apply pressure primarily to the spine of scapula muscle, rhomboideus major muscle and the serratus posterior superior muscle. The lower lumbar bladders  70  and  72  are each specifically shaped to apply pressure primarily to the thoracolumbar facia, spinalis thoracis, erector spinae muscle, longissimus thoracis, iliocostalis lumborum, latissimus dorsi, trapezius and serrated posterior inferior oblique muscle.  
         [0040]    The height of the back support system  10  of this invention is selected so that the lumbar vertebrae of the user&#39;s spine will generally be located between the lower portions of the lower lumbar bladders  70  and  72 . The remaining portion of the back support system  10  is located primarily in the area of the thoracic vertebrae of the spine. The back support system of this invention is not designed to have any contact with the cervical lumbar region of the spine.  
         [0041]    Rear inflatable bladder  48  is mounted within a base which comprises fixed plate  74  and movable plate  76  with bladder  48  mounted between plates  74  and  76 . The movable plate  76  is mounted by a hinge  78  to the lower edge  80  of the fixed plate  74 . At the upper edge  82  of the fixed plate  74  there is mounted a flexible dust cover  84 . The axis of hinge  78  is perpendicular to the mid-axis  98 . The fixed plate  74  is mounted against a chair back  73 , shown in FIG. 3.  
         [0042]    When the rear inflatable bladder  48  is not activated, the plates  74  and  76  are in the position shown in FIG. 6 of the drawing. However, when switch  46  is pressed, pressurized air is supplied into the bladder  48  and the bladder  48  can be extended to the maximum position depicted by arrow  86  which will normally be about ten degrees. The dust cover  84  prevents foreign material from entering to within the wedged shape cavity  88  that is produced between the fixed plate  74  and the movable plate  76 .  
         [0043]    The fixed plate  74  is to be mounted either on a chair back or as a chair back. For example, in the environment of a wheelchair, the fixed plate  74  can be mounted by mounting brackets  90  and  92  to the frame structure of the wheelchair, which is not shown. These mounting brackets  90  and  92  are shown in FIG. 5. Activating and causing pressurized air to enter the bladder  48  will change the position of the movable plate  76  from an inclined position, as shown in FIG. 6, to an upright position, shown in FIG. 7. It is to be understood that the amount of inclination or the amount of uprightness is to be manually selected according to the individual&#39;s desires. FIG. 5 also shows the control housing mounted on the rear surface of the fixed plate  74 .  
         [0044]    When the user presses switch  44 , pressurized air is supplied to the right bolster bladder  50  which is wedged between the movable plate  76  and right bolster plate  94 . The right bolster plate  94  is hingedly connected to the movable plate  76  by means of a hinge  96 . Hinge  96  is located substantially parallel to the mid-axis  98 . Mid-axis  98  is located at the transverse center of the movable plate  76  and extends longitudinally. Dust cover  100  connects between the movable plate  76  and the right bolster plate  94  to prevent foreign material from entering the wedge shaped cavity  102  formed between the movable plate  76  and the right bolster plate  94 . When the user presses switch  44 , inflation of the bladder  50  will occur which will cause the right bolster plate  94  to move from the retracted position, shown in FIG. 3, to the expanded position, shown in FIG. 4. The expanded position will apply pressure to the right side of the user when sitting in a chair to provide lateral support to the user of the chair.  
         [0045]    When the user presses switch  42 , pressurized air is to be supplied to the left bolster bladder  62  which is wedged between the movable plate  76  and a left bolster plate  104 . The left bolster plate  104  is hingedly connected by a hinge  106  to the movable plate  76 . The axis of the hinge  106  is substantially parallel to the mid-axis  98 . A dust cover  108  extends between the movable plate  76  and the left bolster plate  104  to prevent foreign material from entering the wedged shape cavity  110  which is located between the movable plate  76  and the left bolster plate  110 . When the user causes pressurized air to enter into the left bolster bladder  52 , pressure will be applied to the left side of the user to provide lateral support to the user of the chair.  
         [0046]    Mounted on the frontal surface of the right bolster plate  94  are bladders  62  and  54 . Mounted on the frontal surface of the left bolster plate  104  are bladders  60  and  68 . Bladders  54  and  62  are covered by a fabric or plastic cover  112 . The bladders  60  and  68  are covered by a cover  114 , which is also formed of plastic or fabric. It is to be understood that each of the inflatable bladders included within this invention are to be formed as a sheet material enclosure with the wall of such constructed of either a rubberized fabric or plastic material. Each bladder can be replaced for repair. The maximum pressure supplied to each bladder will generally not exceed two pounds per square inch. The bladder covers are removable for washing purposes and then are replaceable.  
         [0047]    Bladders  56  and  58  are fixedly mounted onto the movable plate  76  with bladder  56  being located to one side and spaced from the mid-axis  98  and bladder  58  located to the opposite side and spaced from the mid-axis  98 . Similarly, the bladders  64  and  66  are fixedly mounted onto the movable plate  76  with bladder  64  located on one side of the mid-axis  98  and bladder  66  located on the opposite side of the mid-axis  98  and spaced therefrom. Similarly, the bladders  70  and  72  are fixedly mounted onto the movable plate  76  with bladder  70  being located on one side of the mid-axis  98  and bladder  72  located on the opposite side of the mid-axis  98  with both the bladders  70  and  72  being spaced from this mid-axis  98 . The mid-axis  98  is to basically align with the spine of the user. This will result in that there is no pressure being applied by a bladder directly to the spine. The applying of pressure to the spine at times, for certain individuals, can become uncomfortable. The upper lumbar bladders  54 ,  56 ,  58  and  60  are designed to apply pressure to the muscle group of the upper lumbar region of a person&#39;s back. The middle lumbar bladders  62 ,  64 ,  66  and  68  are designed to apply pressure to the middle lumbar muscle group of the person&#39;s back. Bladders  70  and  72  are designed to apply pressure to the lower lumbar muscle group region of the person&#39;s back. In essence, the arrangement of the bladders mirrors the musculature structure of the user&#39;s back. Bladders  56 ,  64  and  70  are covered by a cover  116 . Bladders  58 ,  66  and  72  are covered by a cover  118 . Bladders typically will be constructed of polyester/polyurethane or polyurethane/vinyl material and not flammable. The covers  112 ,  114 ,  116  and  118  are also constructed of a fabric which is not flammable.  
         [0048]    For a description of the constructing of each of the bladders, reference is to be to bladder  70  shown in detail in FIGS. 8, 9 and  10 . Bladder  70  has an internal chamber  71  located internally of fabric cover  116 . Located within chamber  71  is an open cell foam pad  73 . Pad  73  will normally be constructed of polyurethane. Air is supplied internally of sheet  75  within internal chamber  79  through outlet conduit  76  through port  77 .  
         [0049]    The foam that is used within each of the bladders is to have an indention load displacement of between twelve to twenty-six. Generally, this indention load displacement is within the low range. Basically, the trait of the foam, such as foam pad  73 , is to be such that when it is compressed and the force is released from the foam that it will quickly spring back to its original shape.  
         [0050]    With ambient air pressure in bladder  70 , the position of bladder  70  will be as shown in FIG. 8 where sheet  75  closely conforms to foam pad  73  and cover  116  abuts sheet  75 . Adding of pressurized air to within internal chamber  79  causes expansion of sheet  75  and fabric cover  116  as shown in FIG. 9. When a person&#39;s body  81  leans against cover  116  and applies pressure, the inflated appearance of bladder  70  is substantially eliminated with sheet  75  being pressed against pad  73  assuming the position shown representatively in FIG. 10.  
         [0051]    Pressing of switch  40  will cause pressurized air to be supplied simultaneously to bladders  54 ,  56 ,  58  and  60 . Pressing of switch  38  will cause pressurized air to be supplied simultaneously to bladders  70  and  72 . Pressing of switch  36  will cause pressurized air to be supplied simultaneously to bladders  62 ,  64 ,  66  and  68 .  
         [0052]    Each of the bladders that have been previously discussed can be vented through their supply conduits  24 ,  26 ,  28 ,  30 ,  32  and  34  by merely pressing of the switches  36 ,  38 ,  40 ,  42 ,  44  and  46  in an opposite direction where this venting occurs through the valve, which is not shown, that is associated with each of the switches  36 - 46 . This venting causes their respective inflatable bladders to deflate or move to a lower amount of inflation, again according to the individual&#39;s desires. At times, the user can change the inflation of bladders to alter the pressure that is being applied. This changing of the pressure is in order to increase comfort and minimize the possibility of creating of any sore in conjunction with a user&#39;s back. The use of bladders provides localized pressure but distributes the pressure.  
         [0053]    Connecting with the conduit  24  is a connecting conduit  120 . The connecting conduit  120  connects at one end with the bladders  62  and  64  and at the opposite end with the bladders  66  and  68 .  
         [0054]    The supply conduit  28  connects to a connecting conduit  122  with one end of the connecting conduit  122  connecting with the bladders  54  and  56  and the other end of the connecting conduit  122  connecting with the bladders  58  and  60 . Similarly, there is a connecting conduit  124  that connects with a supply conduit  26  with one end of the connecting conduit  124  connecting with bladder  70  and the opposite end of the connecting conduit  124  connecting with bladder  72 .  
         [0055]    In summary, the user, when utilizing the back support system  10  of this invention, has the capability of changing the overall tilt of the back support system  10  and also has the option of increasing or decreasing lateral support by moving of the right bolster plate  94  or the left bolster plate  104 . Additionally, the user has the capability of applying increased pressure to the lower lumbar region through bladders  70  and  72 , through the middle lumbar region through bladders  62 ,  64 ,  66  and  68  or the upper lumbar region through bladders  54 ,  56 ,  58  and  60 . The back support system is designed to be constructed in any convenient size with typical sizes being twelve inches, fourteen inches, sixteen inches, eighteen inches, twenty inches, twenty-two inches, twenty-four inches, twenty-sic inches, twenty-eight inches and thirty inches.  
         [0056]    By the design of this unique medical device, structural support of the back is maintained. Prolonged seating can cause musculo-skeletal problems. This design allows postures to adjust and reduce the lowest disc compression which ultimately causes discomfort and pain. During sitting, activity of the back muscles is similar to that during standing, but in supported sitting, as with elbows resting on the knees there is no activity in the lumbar back muscles, and with arms resting on an armrest, back muscle activity is decreased. In reclined sitting, the backrest supports the weight of the thorax, lessening the need for muscular support. Increasing the declination of the backrest of a seat decreases lumbar back muscle activity. As the spine bends forward, there is an increase in the activity of the back muscles. Gravity, but the extent produces the movement of forward flexion and the rate at which it proceeds, is controlled by the eccentric contraction of the back muscles and tension in its posterior ligaments. If forward flexion increases, transition of spinal-load bearing from muscles to the ligaments system takes place. The downward direction of their action as the back muscles contract exert a longitudinal compression of lumbar vertebral column, and this compression raises the pressure in the lumbar intervertebral discs. Disc pressures and myoelectric activity of the back muscles quantifies the stresses applied to the lumbar spine in various postures. The erector spinae muscle group plays a critical role in the dyna{acute over (m)}ic stability of the lumbar spine. As the spine bends forward, there is an increase in the activity of the back therefore is associated with the rise in nuclear pressure. When measured at intervertebral discs, the nuclear pressure correlates with the degree of myoelectric activity in the back muscles. As muscle activity increases, disc pressure rises. At a certain point during forward flexion, the activity in the back muscles ceases and tension in its posterior ligaments increases. This phenomenon takes place only when the spine has reached about ninety percent maximum flexion. To control this activity the back support system  10  will adapt to the following, postures leaning back using a reclined backrest give the lowest lumbar-sacral disc loading regardless of the inclination the direct location of the seat and by postures in which an individual is bending forward with the spine kyphotic give the highest disc loading regardless where the individual has been seated or positioned. It is advantageous to tilt the back forward or backward by five degrees rather than to have a horizontal seat pan in forward bending postures. If an erect trunk posture is attained or a reclined backrest is in use disc compression will be altered when the recline function moves forward or backwards by five degrees. There is a correlation between discomfort and disc compression.  
         [0057]    The back support system  10  allows the user to move in multiple planes rather than a fixed manner. Another advantage enables the occupant to have multiple back positions by inclining and reclining and increasing pressure along major muscle groups to facilitate postural changes. The back support system  10  is a multi-positioning device that reduces back and lower back pain by increasing the over muscular activity of the back.  
         [0058]    The present invention may be embodied in other specific forms without departing from the essential attributes thereof. Reference should be made to the appending claims rather than the foregoing specification as indicating the scope of the invention.