Abstract:
A lightweight and portable pneumatic lifting device includes an inflatable, trapezoidal side shaped and self-contained bladder housed in a removable, washable material. The inferior surface of the bladder contains a rigid base for stability. Located on one side of the bladder is a compartment to house the self-contained air compressor. A valve or valves is provided for inflation and deflation of the bladder.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     A. Field of Invention  
         [0002]     The present invention relates to the field of medical devices and, more specifically, to an inflatable device used to assist an invalid or physically disadvantaged person in moving from a seated position to a standing position.  
         [0003]     B. Description of the Related Art  
         [0004]     The impact of the aging population of the United States is well recognized and has profound socioeconomic implications, not the least of which is the conversion of nursing home care into a major industry. Also, not the least of the inevitable effects of aging is the loss of lean body (muscle) mass with the result of muscle weakness. There are several contributing factors involve in this loss. Loss of appetite, poor dentition, lack of exercise, dwindling blood supply (particularly to the lower extremities) and down regulation of metabolism are all conspirators in this process. While these factors can be offset by improved nutrition and regulated exercise, the results are related to a maintained status quo rather than a return to physical vigor. Further loss may be forestalled but regeneration of lost muscle is dependent on synthesis of muscle protein and restoration of cellular activity. Both of these requisites are the victims of the aging process of muscle. The bottom line of this aspect of the aging process is that muscle weakness is the expected companion of the senior population.  
         [0005]     Significant physical strength is not a prerequisite to a self-sufficient life style, but physical mobility is, and a level of muscle strength is a requirement for mobility. A consistent feature of early impairment of mobility is difficulty in getting up from a chair. Weakness of the extensors of the knee (the quadriceps femoris) results in difficulty rising from a chair, stair climbing and even walking. Limitations in those functions contribute to further activity restrictions which in turn result in progressive muscle weakness. Progressive limitations of physical activity complete a cycle of physical deterioration and diminishing lifestyle.  
         [0006]     The preservation of mobility is thus the key to the maintenance of a useful, independent and psychologically fulfilling lifestyle. To that end the use of a device that permits the capability of rising from a chair and allowing walking is offered as a practical solution to the problem of physical imprisonment by the inability to move independently.  
         [0007]     Various types of devices have been proposed to address this problem such as U.S. Pat. Nos. 3,479,087 to Burke, 5,375,910 to Murphy and 5,505,518 to Pike. These patents all disclose a pneumatic powered seat erector that consists of an upper and lower plate hinged together at one end. The devices also include an inflatable bladder positioned between the plates. As the bladder inflates, the plates begin to separate at the edge opposite the hinge causing the upper plate to pivot forward—thereby raising the individual from a seated position to a standing position. All three patents do not mimic the initial movement of the seated individual as he or she begins stand. At inflation, the upper plate pivots forward so that the individual is lifted only from the back and not from the front. This pivot only action causes the individual to slide off the seat.  
         [0008]     U.S. Pat. No. 4,629,162 to Porché discloses a portable pneumatic lift that includes an inflatable single chamber air bag, a pressurized air source and a remote control for operation of the air source. The air bag is wedged shape in that when inflated the height at the back of the air bag is about 13 inches and the height at the front of the air bag is about 10 inches. Although inflation of the air bag in Porché better mimics the initial movement of a seated individual as he or she begins to stand, the angle of pitch is not sufficient to fully assist the individual to stand from a seated position.  
         [0009]     U.S. Pat. No. 4,905,329 to Heilner discloses an inflatable seat cushion consisting of an inflatable ring whereby the front portion of the ring is restricted during inflation thereby allowing the back portion of the ring to inflate at a height 3-7 times that of the front portion. Although Heilner allows for some elevation in the front portion, the inflatable ring must be sized appropriately to prevent an individual from falling through the center of the ring.  
         [0010]     U.S. Pat. Nos. 5,361,433 and 5,742,957, both to Vanzant, disclose an inflatable bag having multiple cavities that inflate sequentially. The devises of these patents, however, do not provide a means for a washable fabric cover or the ability to place the compressor within a pocket or compartment on either side of the bladder.  
         [0011]     What is needed is a device that elevates and pitches forward the seated individual, which mimics the change to a standing position. This will facilitate the effective contraction of quadriceps muscles by reducing the extent of muscle shortening necessary to allow straightening of the legs at the knee. As the present invention discloses, a forward pitch level of approximately thirty degrees is sufficient to produce the desired effect. This degree of inclination can be achieved by an approximate seven inch elevation of the dorsal plane of the seated position over the ventral plane. This effect can be accentuated by a two inch elevation of the seat cushion itself. The positional change produced by this device thus mimics the initial movements of the unassisted rise from a seated position in a normal circumstance. Therefore, performance of the initial movement by the device allows the completion of the standing process by the user. In this way the disadvantages known in the art cam be overcome in a way that is better, more efficient and that provides better overall results.  
       SUMMARY OF THE INVENTION  
       [0012]     The present invention overcomes the aforementioned disadvantages by providing an inflatable device that produces a forward pitch level of approximately 30 degrees that is sufficient to produce the desired effect. In addition, the degree of inclination can be achieved by an approximate 7 inch elevation of the dorsal plane of the seated position over the ventral plane. This effect can be accentuated by a 2 inch elevation of the seat cushion itself. The positional change produced by this device thus mimics the initial movements of the unassisted rise from a seated position in a normal circumstance. Therefore, performance of the initial movement by the device allows the completion of the standing process by the user.  
         [0013]     It is therefore one object of the present invention to provide an inflatable lift device that mimics the initial movement of a seated person to a standing position.  
         [0014]     It is another object of the present invention to provide an inflatable lift device where the front portion rises to assist the seated person to a standing position.  
         [0015]     It is yet another object of the present invention to provide an inflatable lift device that is portable and lightweight.  
         [0016]     It is yet another object of the present invention to provide an inflatable lift device with one embodiment that contains a single valve for inflation and rapid deflation.  
         [0017]     It is yet another object of the present invention to provide an inflatable lift device that provides a removable washable cover. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:  
         [0019]      FIG. 1  is a perspective view of the present invention showing the bladder with the cover removed.  
         [0020]      FIG. 2  is a perspective view of the bladder with the cover attached.  
         [0021]      FIG. 3  is a top view of the support plate.  
         [0022]      FIG. 4  is a side view of the base showing the location of the compressor compartment.  
         [0023]      FIG. 5  is a side view of the inflatable bladder.  
         [0024]      FIG. 6  is a perspective view of the inflated bladder showing one embodiment with separate intake and exhaust valves.  
         [0025]      FIG. 7  illustrates the exhaust valve in the closed position.  
         [0026]      FIG. 8  illustrates the exhaust valve in the opened position. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]     Referring now to the drawings wherein the showings are for purposes of illustrating a preferred embodiment of the invention only and not for purposes of limiting the same,  FIGS. 1 and 2  show an air lift seat apparatus  10  that includes a base  12 , a bladder  14 , an intake/exhaust valve  16 , a pocket or compartment  18 , a self-contained air compressor  20  and a removable cover  22  ( FIG. 2 ). The base  12  is preferably made of a rigid polystyrene material to provide stability to the apparatus when placed on a chair. The base  12  has a front  24 , a back  26  and two sides  28 ,  29  and is preferably about 18 inches wide, 18 inches deep and 1 inch in height. However, the base  12  can be any suitable size to fit a standard sized chair, seat cushion of a sofa or similar type of sitting apparatus as along as chosen with sound engineering judgment.  
         [0028]     Referring now to  FIGS. 2 and 3 , in the preferred embodiment a connecting means  27  is provided to selectively attach the cover  22  to the base  12 . The connecting means  27  may be of any type chosen with sound engineering judgment such as snaps  30 , hook and loop fasteners such as Velcro® (not shown) or a zipper (not shown). The cover  22  can be made of any material chosen with sound engineering judgment but preferably is formed of a washable fabric. In the preferred embodiment, a slip prevention material  38  is provided on at least a portion of the top  23  of the cover  22 . This slip prevention material  38  makes it difficult for a person to slip off of the lift seat apparatus  10  while the bladder  14  is inflating. The cover  22  is preferably sized slightly larger than the bladder  14  when the bladder  14  is fully inflated to facilitate easy application and removal of the cover  22 .  
         [0029]     With reference now to  FIGS. 3 and 4 , the compartment  18  that holds or houses the air compressor  20  can be located on either side of the bladder  14  to facilitate use by either hand of the seated person. The compartment  18  is preferably attached to either side  28 ,  29  of the base  12  and is located near the front  24  of the base as shown in  FIG. 3 . The compartment  18  can either be an integral part of the base  12  or can be a separate piece that attaches to the base  12  by any means chosen with sound engineering judgment. The preferred height of the compartment  18  is approximately 2 inches. The length and the width of the compartment  18  are determined by the type of air compressor used to inflate the bladder  14 . The preferred air compressor  20  is a portable, commercially available, rechargeable type compressor commonly known in the art and thus will not be described further. An air hose  32  is provided to transport air from the air compressor  20  to the bladder  14 . As shown in  FIG. 1 , the first end  34  of the hose  32  is connected to the air-compressor  20  and the second end  36  of the hose  32  is connected to the intake/exhaust valve  16  by means commonly known in the art.  
         [0030]     Referring to  FIGS. 1 and 5 , the bladder  14  is preferably made from a single piece of material. The material can be any type of flexible material chosen with sound engineering judgment that allows the bladder  14  to expand upon inflation and contract upon deflation. The bladder  14  further contains a front portion  40 , a rear portion  42 , two trapezoidal shaped side panels  44 ,  45 , a top  46  and a bottom  48 . The length and width of the bottom  50  are similarly sized to fit the base  12  as described above. The bladder  14  is designed to mimic the initial movements of a seated person when that person begins to stand. Therefore, when the bladder  14  begins to inflate the front portion  40  and the rear portion  42  will inflate simultaneously. When fully inflated, the rear portion  42  is at least three times higher than the front portion  40 . In one embodiment the rear portion  42  is nine inches high and the front  40  portion is 2 inches high.  
         [0031]     With reference now to  FIG. 1 , an intake/exhaust valve  16  is located on the side  44  of the bladder. The valve can be located on either side  44 ,  45  to facilitate use by either hand of the seated person as with the compartment  18  as described above. The valve  16  can be any type of mechanical valve commonly known in the art. In one embodiment the valve  16  is a ball type valve  50  as shown in  FIGS. 7 and 8 . The ball valve  50  further consists of a handle  52 , a core  54  and an aperture  56  and a housing  58 .  FIG. 7  shows the ball valve  50  in the open position. When the ball valve  50  is in the open position the aperture  56  is parallel to the housing  58  and air can enter or escape from the bladder  14 .  FIG. 8  shows the ball valve  50  in the closed position. When the ball valve  50  is in the closed position the aperture  56  is perpendicular to the housing  58  and air cannot enter into or escape from the bladder  14 . Another embodiment of the present invention is shown in  FIG. 6 . In this embodiment the apparatus contains two valves. The first valve  60  is the intake valve and the second valve  62  is the exhaust valve. In this embodiment, the hose  32  connects the air compressor  20  to the intake valve  60 . The exhaust valve  62 , when opened, permits air to exit the bladder to the atmosphere. As a result, the bladder can be deflated without removal of the air compressor hose  32 .  
         [0032]     Operation of the present invention will now be described. The air lift seat apparatus  10  can be used to assist a person in moving from a standing position to a seated position and from a seated position to a standing position. To move from a seated position to a standing position, the person simply turns the handle  52  on the ball valve  50  and rotates it 90 degrees until the aperture  56  is parallel to the housing  58 . The person then activates the air compressor  20  thus allowing air to enter the bladder  14 . As the bladder  14  begins to inflate the front portion  40  and the rear portion  42  begin to rise simultaneously thereby slowly lifting the seated person. As the front portion  40  reaches its maximum height as described above, the rear portion  42  will continue to inflate thereby creating a pitch angle. As the rear portion  42  continues to inflate, the seated person is further lifted until the rear portion  42  reaches its maximum height as described above thereby gently assisting the seated person to a standing position. Conversely, in assisting a person to move from a standing position to a seated position, the person simply inflates the bladder  14  as previously described. Once the bladder  14  is fully inflated the person deactivates the air compressor  20 . The person then rotates the ball valve  50  by 90 degrees until the aperture  56  is perpendicular to the housing  58 . This will prevent air from escaping from the bladder  14  until the person is ready to be seated. The person then backs into the apparatus  10  and places his/her weight onto the cover  22  that is positioned over the bladder  14 . Once the person is leaning against the apparatus  10 , the person then rotates the ball valve  50  by 90 degrees until the aperture  56  is parallel to the housing  58  thereby permitting the air to escape from the bladder  14  thus gently assisting the person to move from a standing position to a seated position.  
         [0033]     The preferred embodiments have been described, hereinabove. It will be apparent to those skilled in the art that the above methods may incorporate changes and modifications without departing from the general scope of this invention. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof.