Patent Application
20050067861
1. Field of the Invention
This invention relates to certain significant improvements in wheelchairs and particularly to improvements in the transportation, storability, and comfort of reclining and non-reclining wheelchairs, such as those shown and described in my U.S. Pat. Nos. 5445,443 and 6,533,358. This invention also provides a kit which permits a foldable non-adjustable straight-backed wheelchair to be converted into a rigid foldable, adjustable-backed wheelchair, wherein the back of the wheelchair can be positioned along a continuum between a fully reclined position and an upright position and wherein the back portion of the kit is configured with the back support of this invention, which could also be used to provide the support needed to accommodate patients suffering from spinal abnormalities or kyphosis (hunchback).
2. Description of the Prior Art
Prior art wheelchairs have either a non-supporting, flexible, foldable soft back, which does not provide the necessary back support for patients who need it when using them regularly, or have a rigid back which provides the necessary support but does not fold, making transport and storage very awkward.
In particular, prior art folding wheelchairs have been provided with flexible, sheet-like, non-supportive seat backs. These seat backs were often nothing more than an expanse of flexible material attached to the side frames of the wheelchair. These seat backs have proven to be undesirable for many reasons. Primarily, these seat backs do not provide the back support needed by most patients which leads to discomfort and possibly aggravation of existing back problems. This problem is acute for patients seated in foldable wheelchairs with flexible backs and seats, which tend to hammock. Moreover, presently available reclining back wheelchairs are not configured to accommodate spinal deformities such as kyphosis. Furthermore, these prior art seat backs could not be modified to provide for the individual needs of many patients. Finally, many prior art seat backs provided only a single upright position for patients.
Certain kits are available to convert these conventional folding non-reclining wheelchairs into reclining back wheelchairs and TLSO devices. One such kit is sold by Medisol U.S.A. of 9713 Factorial Way, South El Monte, Calif. 91733 under the trademark REHABACHAIR. The kit produced by Medisol is described in U.S. Pat. Nos. 5,445,433 and 6,533,358 which patents are hereby incorporated by reference in their entirety. These prior art kits, however, while very useful in their ability to convert wheelchairs from non-reclining mode to reclining mode, do not provide comfortable support for patients with severe spinal deformities in combination with foldability for ready transport or storage.
Various non-folding reclining back wheelchairs are available. One such chair is the BCW recliner chair, offered by Wheelchair Institute of Kansas, of 910 Main Street, LaCrosse, Kans. 67548. However, the available non-folding reclining wheelchairs are heavy, bulky and very costly when compared to non-reclining wheelchairs.
Prior art wheelchairs are also available which generally comprise a one-piece back support cushion of fixed density or rigidity which does not provide the particular support or comfort needs for persons with back problems.
There accordingly remains a need to provide a reclining wheelchair having improved comfort and back support, especially for patients with spinal abnormalities, while at the same time providing a readily foldable wheelchair for ease of transport and storage. There also remains a need for a retrofit kit which can be used to convert conventional wheelchairs, e.g., folding non-reclining straight back wheelchairs, into a folding reclining wheelchair that provides improved comfort and support, especially for patients with kyphosis and/or other abnormalities, combined with foldability for ease of transport and storage.
The invention disclosed herein solves certain significant problems associated with prior art wheelchairs. This invention provides a wheelchair which combines the attributes of a supportive, comfortable seat back with the transportability and storage benefits of a foldable wheelchair. The combination of rigid support and comfort provided by this invention is ideally suited for patients who suffer from a curvature of the spine, particularly kyphosis. The added benefit of foldability increases the mobility of patients by providing easy transport and storage of the wheelchair. Moreover, the design of this invention allows for the wheelchair to be customized to accommodate the spinal deformities of any particular patient. In this manner, this invention not only provides comfort and quality of life to patients but also may provide therapeutic treatment by providing the needed support.
This invention comprises a wheelchair with a book-style folding feature in the seat back. The seat back is capable of providing needed support while in the non-folded condition by means of the placement at least two rigid but cushioned, panels provided on either side of a generally centrally located, relatively flexible, longitudinally extending, cushioned area—analogous to the hinged back or spine of a book. To enable the wheelchair to be “folded”, i.e. compressed so that the wheels are closely adjacent each other, the rigid panels of the seat back are folded about the flexible spine, in a manner similar to the hinging of the covers of a book about its spine, simultaneously with the folding of the seat portion of the wheelchair.
This invention comprises, also, a retrofit kit e.g. for converting a folding, non-reclining wheelchair having two side frames, a seat portion and a standard seat back, into a folding, reclining wheelchair having an improved seat back which comfortably supports the patients in variably reclined positions. The kit includes an adjustable strap which is connected to the side frames of the wheelchair. This strap may include buckles or other quick release fasteners for releasing the strap. The kit also includes an improved folding seat back of this invention to replace the standard seat back found on most wheelchairs. This improved seat back is configured to provide the needed support for all patients including those with spinal deformities. The seat back may be hingeably or flexibly connected to each side frame. Ideally, the adjustable strap and rear of the seat back are provided with corresponding hook and loop fastening strips such as Velcro. By adjusting the lengths of the straps or simply repositioning the straps along the Velcro strips, the seat back may be raised to an upright position or lowered to a reclining position. This is facilitated by the hinges or flexible fasteners which connect the seat back to the side frames.
Significant additional comfort of this invention's seat back is provided in several ways. Kyphosis patients, in particular, may have large curvatures in different locations along the spine. This invention allows customized cut outs to be made in the right and/or left support panels of the seat back—which correspond to individual patient's spinal abnormality. These comfort features of my improved seat back relieve the irritation, chafing and, in extreme cases, sores caused by conventionally backed wheelchairs. These problems with conventionally backed wheelchairs are known to aggravate spinal conditions when they occur in patients.
The back support of this invention provides good support both in an upright and reclining position. Substantial back support is required by all wheelchair patients, particularly in a reclined position, and the back support of this invention keeps the spine in a more natural position while reclined. In a patient with abnormal spinal curvature such support also may prevent aggravating the condition.
Conventional foldable wheelchairs have either a non-supporting sling back, soft back, which does not provide the necessary back support for patients who need it, or have a rigid back which provides the necessary support but does not fold, making transport and storage very awkward. A prior art retrofit kit modifying the conventional wheelchair with a more supportive, reclining seat back is available. However, this prior art kit does not provide foldability.
Such wheelchairs come in a variety of heights and widths as well as having various configurations of side frames 22. The present invention is designed to be used on the various folding wheelchairs 20 known in the art. The present invention can readily be customized to fit most such wheelchairs by replacing the sling seat 26 which does not provide the back support needed by many patients.
As depicted in
The seat back 28 of the present invention is typically mounted to the side frames 22 of the wheelchair 20a. At least one flexible fastener 30 mounts the seat back to each side frame. The seat back 28 of the present invention may replace the sling back 26 of the prior art wheelchair or the wheelchair may be originally provided with such a seat back.
The flexible fasteners 30 may comprise a variety of configurations. The function of the flexible fasteners is to pin the seat back 28 to the side frames 22 at the location of fastening while allowing relative motion between the side frame and seat back. Primarily for purposes of folding, the flexible fasteners need to allow the seat back to bend backward or forward. However, the flexible fasteners must also firmly hold the seat back to the side frame while a patient is resting against the seat back. One type of fastener shown to be effective for this purpose is a loop of material sewn to the seat back which is bolted to the side frame as shown in U.S. Pat. No. 6,533,358. A hinge type fastener may also provide the properties needed for folding and support.
As depicted in
As depicted in cross-section in
The rigid panels 32 may be formed of a variety of materials. Plywood panels have proven to have the necessary rigidity for this purpose. Sheets of plastic or light weight metal may also be appropriate. The rigid panels may be flat or form a curved surface to conform to a patient's back. One possible configuration of the rigid panels is depicted in
As the wheelchair 20 is folded by bringing each side frame 22 into close proximity, the seat back 28 of the present invention will fold like a book about axis 40. This configuration is shown in top view in
Ideally the foam padding comprises a front panel 42 and a rear panel 44. Each of these foam panels may completely cover one side of rigid panels 32. The foam panels and the rigid panels may all be fastened together by a variety of fastening means. Preferably the foam panels 42, 44 and the rigid panels 32 are all internally secured by a suitable glue to form the unitary seat back 28. Alternatively a series of pins, bolts or similar fasteners may be used to connect the foam panels and the rigid panels into a flexible seat back.
The material used to make the foam padding 34 is preferably a sturdy, durable foam with suitable memory properties. Foams with suitable memory properties are those that do not immediately snap back to their original condition after being compressed. Thus, the foam panels 42, 44 may retain their compressed condition in those areas which are compressed by the patient's back. This adds significantly to the patient's comfort. A suitable rubber foam known to have the appropriate combination of properties is manufactured by Vanguard Foam and Packing in Gardena, Calif. as HR-28250.
The front panel 42 and rear panel 44 of the foam padding 34 ideally cover the entire front and rear surfaces of the seat back 28, including the flexible spine 38 formed along the longitudinal axis 40 of the seat back between the rigid panels 32. By flexing the foam padding along the flexible spine 38, the seat back may folded. Ideally the foam material is also sturdy enough to withstand repeated folding and unfolding of the seat back.
Furthermore, having a flexible spine 38 along the longitudinal axis 40 of the seat back 28 greatly increases the comfort provided by the seat back. The flexing of the foam material in the spine of the seat back provides a certain amount of give in response to pressure applied by the patient. This prevents the otherwise supportive and rigid seat back from having a hardened, solid feel particularly in the area of the seam. Thus, although the seat back provides rigid support on both the left and right side of the patient's back where support is most needed, the spine 38 is flexible along the patient's spinal area where comfort is most needed.
Moreover, the rigid panels 32 may be sculpted to provide the variable support needed by some patients. Certain deformities of the spine create an irregular curvature such as produced by kyphosis. Kyphosis (known as hunch back) forms outward extending humps in a patient's back. To accommodate these and other deformities, the rigid panels may have cutouts 46 in the affected area. The cutouts are areas in which material has been removed from the rigid panels to create a hole covered by the foam padding 34. Ideally the area formed by these cutouts corresponds with the patient's spinal deformity. In this manner the affected area of the spine may be compressed against the foam padding of the seat back 28 rather than the rigid panels. Possibly, the seat back may be customized for individual patient's support and comfort needs, by sculpting cut outs in the rigid panels as needed.
Preferably the seat back 28 includes a protective covering 36 which surrounds the exterior of the seat back. The covering may be formed of a durable fabric to protect the interior of the seat back and adds to the overall strength and durability of the seat back. This covering also may include a zipper 48 so that the covering may be removed. The covering may also be waterproof to prevent water damage. Since the covering comprises the visible exterior of the seat back it may also provide a decorative quality to present a pleasing look to the seat back and the wheelchair 20.
A prior art kit modifying the conventional wheelchair 20 into a reclining wheelchair replaces the non-reclining flexible seat back with a rigid reclining seat back 29. The prior art kit also provides for adjustable straps 50 which connect the reclining seat back to the conventional side frames 22. These adjustable straps include loops 52 which wrap around the side frames and snaps, buckles or adjustment rings to modify the length of the straps. The loops wrap around the conventional side rails and back around the rear surface of the seat back. By lengthening or shortening the straps using the buckles 54 the seat back may be adjusted to a variety of reclining configurations. The adjustable strap and rear of the seat back may also be provided with corresponding hook and loop type fastening strips 56 such as Velcro.
The reclining seat back 29 of the prior art kit is provided in a variety of configurations. The reclining seat back may be curved and/or padded to provide for the individual back support needs of the patient. This reclining seat back may be configured as a thoracic-lumber-sacral correcting orthosis (“TLSO”) device. With the TLSO and reclining features of this seat back, the prior art kit has modified a conventional wheelchair into a device providing both rehabilitative care and mobility to a patient.
The prior art kit has also provided several other wheelchair modifications for rehabilitative care. An accessory padded seat cushion may be provided as relatively stiff or soft according to patient needs. Covers may also be provided to cushion the arm rests. For patients that require additional support, torso restraining straps may be attached to the seat back and configured to wrap about the torso or abdomen of the patient to avoid slipping.
As depicted in
The drawings and foregoing description are not intended to represent the only form of the invention in regard to the details of its construction and manner of operation. It will be evident to those skilled in the art that modifications and variations may be made without departing from the spirit and scope of the invention. Changes in form and at the proportion of parts as well as the substitution of equivalents are contemplated and although specific terms have been employed, they are intended in a descriptive sense only and not for the purpose of limitation, the scope of the invention being delineated in the following claims:
