Deformity back system - Patent Review 5593211

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BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a modular back system for use in wheelchairs. More particularly, the modular back system of the present invention includes a mounting means and a rigid back shell which may be fitted with a variety of padding systems.

The mounting means is adapted to attach the rigid back shell to the vertical posts of the wheelchair and to adjust the wheelchair rigid back at a selected position and attitude. That is, the mounting means is adapted to selectively adjust the attitude of the rigid back shell, i.e., adjust the height of the rigid back shell with respect to the seat of the wheelchair, to adjust the angle of recline of the rigid back shell and to adjust the depth of the rigid back shell (the distance forward or rearward from the vertical posts). Importantly, the mounting means is adapted to maintain the selected attitude adjustments of the rigid back shell when the wheelchair back system is removed from the wheelchair for transportation or storage. Thereafter, when the back is reattached to the wheelchair, the back will resume its desired, selected attitude and position and height.

The rigid back shell is a hard, relatively rigid surface extending between the wheelchair's vertical posts to provide mechanical support to the back and extending forward, at its lateral edges with a pair of forwardly extending flanges to provide lateral support. The padding system is generally mounted between the two forwardly extending flanges.

In a first embodiment, the padding system comprises a contoured foam pad attached to the rigid back shell. In the preferred embodiment, a fluid pad member comprising an envelope containing a flowable fluid material is positioned to overlie the spinal region of the user. This embodiment is particularly useful for persons which do not require extensive customization of the wheelchair back.

In a second embodiment, the padding system comprises a thin shim attached to the front side of the rigid back shell. A plurality of thicker foam blocks are removably attached to the front side of said shim by a hook and loop fastening means. The blocks form a substantially continuous layer of foam of substantially uniform depth over the front of the shim. In order to customize the padding system for a person with extreme back deformities, one or more of the foam blocks may be removed from the shim to create a recessed area. The recessed area can be used to accommodate any protrusions from the back of the user. A pad member is placed over the foam blocks, including the recessed area. The preferred embodiment of this pad comprises an envelope containing a flowable fluid material and sized to overlie the front surface of the shim and over the front surface of the foam blocks.

The present invention also contemplates the use of transition wedges which are used to provide a smooth transition from the foam blocks into the recessed areas. The present invention also contemplates the use of build-up pads or blocks which may be attached to the front side of the foam blocks and/or to the front side of the shim in the recessed area to further customize the fit of the wheelchair back for the needs of users. Alternatively, the build-up pads may be attached to the front side of a contoured foam pad, as used in the first embodiment.

The padding systems, including the contoured foam pad and blocks, transition wedges, build-up pads, fluid pad, and thin shim are all preferably covered by a fabric cover, which may be an outside cover only, or may be an outside cover enclosing an inside cover and attached to a rigid back shell by a hook and loop fastening means.

BACKGROUND OF THE INVENTION

A significant number of people confined to wheelchairs have body deformities which require a customized back. These people require a wheelchair back which conforms to the shape of their bodies so that they will have enough contact with the wheelchair back to be able to sit upright, without falling over. A custom shaped back also provides comfort and avoids skin pressure that may result in decubitus ulcers (pressure sores). Decubitus ulcers are a very serious problem that requires hospitalization, surgery, and extensive rehabilitation. It is estimated that the current cost of caring for a decubitus ulcer is in the $60,000 to $75,000 range. Naturally, while the patient is hospitalized, he is unable to travel, work, or enjoy other pleasures afforded by mobility, and tremendous and devastating psychological trauma can occur.

The people requiring customized wheelchair backs include those affected with cerebral palsy, muscular dystrophy, multiple sclerosis, head injuries, and other similar ailments. Their needs for customized backs can develop because of kyphosis, scoliosis, and lordosis, plus a combination of twisted deformities in varying degrees of severity.

In order to fit those people with back deformities properly in a wheelchair, the back of the wheelchair must be contoured so as to be able to fit closely to the body's shape so as to provide support over the whole back without putting too much pressure on any one point. Currently, there are three approaches used to develop such a contoured wheelchair back.

The first approach is a custom foam system. In this system, an impression is taken of the body. Once the impression is made, it is sent to a factory site. At the factory, foam is either carved by hand or molded to match the impression of the body shape. An upholstery cover is placed over the carved or molded foam.

This method suffers from a number of disadvantages. For one, it takes a long time to construct the system (typically several weeks). It is also a labor-intensive method and, therefore, expensive. Further, when completed, the system cannot be changed even if it was done incorrectly. Systems on the average take three to six weeks to deliver and three to six weeks to remake if done improperly. The system also cannot be changed if the user's body changes over a period of time. This is especially a problem with children whose bodies quickly and continually change. It is also not possible to fit the user in his own wheelchair which increases the probability of an improper fit at the time of delivery. Rather, the fitting must be done in a fitting frame. Further, there is no opportunity to assess or evaluate the system's effectiveness by the user prior to purchasing it since the system is custom made. In addition, if the foam or cover wears out, the entire system needs to be replaced. Finally, problems with decubitus ulcers are often encountered because of shearing, improper fit, and the user moving Kind not sitting in the molded position.

The second common approach is a foam-in-place system. With this system, a flexible plastic bag is put between the user and a rigid surface. Liquid foam is then injected into the bag. The liquid foam expands into a rigid foam which takes the shape of the user's body. This system also has a number of disadvantages including the fact that it is messy, and that one cannot control the volume of the foam. In addition, the foam-in-place system has all of the above disadvantages of the custom carved molded products.

The third system is marketed under the trade name MATRIX. It allows custom fit to the individual by adjusting a series of metal parts that form to virtually any body contour. The hard matrix is then covered by foam and a fabric cover. This system takes an average of 4-8 hours to fit and is very difficult to refit should someone desire to change the system.

The back system of the present invention overcomes the foregoing problems as is more fully described below.

SUMMARY OF THE INVENTION

The present invention relates to a modular wheelchair back system.

The wheelchair system of the present invention comprises a rigid back shell and a mounting means adapted to removably affix the rigid back shell to the vertical posts of a wheelchair at a selected position in a selected attitude. The rigid back shell is fitted with one of several padding systems.

The Mounting Means

The mounting means is preferably a 4 point mounting means adapted to removably attach the modular back to the wheelchair in a selected position and attitude. In its preferred embodiment, the mounting means includes means to adjust (and maintain in the adjusted position) the back in the desired depth and angle mounted on the rigid back shell and the means to adjust and lock the height mounted on the vertical posts of the wheelchair. The mounting means preferably comprises a pair of post brackets, which are mounted on the vertical posts in a selected position, to accommodate the user's needs. A pair of rods, adjustably affixed to the rigid back shell, engage the vertical post brackets. A pair of U brackets, adjustably affixed to said rigid back shell, engage the wheelchair posts at a location spaced apart from said post brackets. The depth and angle of the back is controlled by adjustment of the position of the rods (which engage the post brackets) and adjustment of the position of the U bracket. Using these adjustments, the depth of the back may be adjusted forward or backwards in the chair, and the angle of the back may be adjusted. The selected back position is maintained by the mounting means even after removal from the wheelchair and later replacement on the wheelchair. The mounting means also does not normally interfere with the arm rest or the folding mechanism of the chair. This allows for easy folding of the wheelchair for transportation.

The ability to recess the back is important to lengthen or shorten seat depth for different users, to adjust backward over time to accommodate growth, and to keep feet in footrests. The ability to recline the rigid back shell is important to accommodate a hip angle of more than 90.degree., to allow users with severe kyphotic deformity to look straight ahead rather than at their lap which results in fatigue to the neck, and to increase stability by allowing the head to rest against a headrest.

These adjustments generally are made one time during fitting, and then do not need to be changed, even when the back system may be removed at a later data to transport it, and is then replaced back in the chair for use. Further, if a change from the initial position is required for example, to accommodate the user's growth, the back may be readjusted in height and forward or backwards in the chair and the angle of the back may also be adjusted and re-set in the new position.

Rigid Back Shell

The rigid back shell includes a monolithic, rigid surface, which is generally contoured with the vertical center line being somewhat to the rear of the lateral edges in a manner to generally conform to the shape of a human back. Attached to the lateral edges are a pair of forwardly extending flanges. The mounting means is attached to the forwardly extending flanges. While whatever type of padding system used is generally mounted within the volume defined by the forward extending flanges.

The Padding System

A first embodiment of the padding system of the present invention relates to contoured backs for wheelchairs for people who do not require extensive customization of the back. More particularly, this embodiment relates to a wheelchair back system comprising a contoured foam pad. In the preferred embodiment a fluid pad member is attached by a hook and loop fastening means such as is commonly available under the tradename VELCRO to overlie the front surface of the contoured foam pad along the length of the spinal region of the user and is attached to the contoured foam pad so that it runs down the middle of the contoured foam pad.

The second embodiment of the padding system of the present invention relates to custom shaped backs for wheelchairs for people confined to a wheelchair and who require an extensively customized wheelchair back. This embodiment comprises removable foam blocks, transition wedges and build-up pads which are attached to a thin shim. The foam blocks provide a substantially continuous layer of foam having a substantially uniform depth of the entire front surface of the shell. Individual blocks can be removed in order to create a padding system surface conforming to the shape of the person's back deformity. The thin shim may be placed in the rigid back shell between the rigid back shell and the foam blocks. Alternatively, build-up pads can be added to the front surface of the layer of blocks in the second embodiment or to the front surface of a contoured foam pad in the first embodiment to further customize the padding system and can be removed or added to the shim so as to create a padding system surface conforming to the shape of the person's deformed back. In addition, a pad member is attached by VELCRO to the shim, the build-up pads, and the foam blocks. The pad member overlies the front surface of the shim and the foam blocks and build-up pads.

To form a proper contour for the shape of the user's back, the foam blocks can be removed from the shim to form a recessed area to provide a customized fit for the user's back with a possible depth of as much as 4 inches behind the original surface of the blocks. The edges of these blocks are preferably beveled so that they do not present a sharp edge to the person's body and generally do not require modification by the person setting up the system. While the preferred embodiment uses blocks which do not generally require modification by the therapist or person doing the fitting, it is understood that another embodiment could employ blocks which generally may be modified for a substantially perfect fit. Foam transition wedges are provided to achieve a smooth transition from the front plane of the removable blocks to the front surface of the thin shim or rigid back shell. Various size transition wedges allow a more custom fit. Additional conformity to the user's back shape is achieved by filling in spaces or voids in areas forward of the front plane of the removable blocks or the contoured foam pad by placement of build-up pads on the front plane of the removable blocks or contoured foam pad. These build-up pads contour to the body shape in order to fill in around the body. The build-up pads can also be used in the recessed area (where the blocks were removed) to build up that area since removing the blocks may create too much of a recessed area.

Foam lateral supports with optional reinforcing VELCRO suspender may be attached to the front surface of the foam blocks or the contoured foam pad with VELCRO.

The Pad Member

The pad member, which overlies the foam blocks, may be a thin foam pad or a flexible envelope containing a flowable fluid material, adapted to smooth out the contour of the back over the blocks, recessed areas and add-on pads.

In the first embodiment, a fluid pad member generally is used to overlie the spinal region of the user, but may be sized to overlie the entire surface of the padding system.

In the second embodiment, a fluid pad member is used to make the customizable padding system have a substantially perfect contoured fit to the user's back. Further, the pad member allows the person to be able to move a little while still maintaining a substantially perfect contoured fit to his body. The pad member covers the whole front surface of the padding system. It is oversized by a significant amount so that it can be draped into any recesses and easily fill in over the build-ups from the build-up pads while overlying the surface of the thin shim. The pad member will also generally smooth out the edges of all the components (i.e. foam blocks, foam lateral supports, build-up pads, transition wedges) underneath it. The pad member is held in its proper position by havin