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US 6,676,215 B1Granted
Pressure-relieving wheelchair seating apparatus
AssigneeThe Research Foundation of State University of New York
InventorsMehendra C. Shah, Arthur A. Ezra
Life of this patent
Estimating the term…
Abstract
A seating apparatus for supporting a lower body region of an immobilized person for avoidance and relief of decubitus ulcers which provides regular intervals of seating pressure reduction below a predetermined seating pressure for a predetermined relief period. The seating apparatus includes a plurality of slats/cushions which may be displaced between a first support position wherein each of the slats/cushions is co-planar with a defined plane and a second displaced position wherein each of the slats/cushions is displaced a distance D from the defined plane for the predetermined relief period whereby capillary blood pressure is reduced below the predetermined seating pressure in the unsupported portion of the lower body region.
Claims19
A seating apparatus for supporting a lower body region of an immobilized person for avoidance and relief of decubitus ulcers, the seating apparatus providing regular intervals of seating pressure reduction below a predetermined seating pressure for at least a predetermined relief period, comprising:
- a plurality of rigid slats, said slats defining a support plane for supporting the lower body region of the immobilized person, each of said slats being movable between a first support position wherein each of said slats is coplanar with said support plane and a second displaced position wherein each of said slats is displaced a distance D from said support plane for the predetermined relief period whereby capillary blood pressure is reduced below the predetermined seating pressure in the unsupported portion of the lower body region, and wherein each of said slats supports a cushion for sitting thereon, said cushion being formed from a viscoelastic material;
- a cage for supporting said slats and configured to allow movement of each of said slats between said first and second position;
- a plurality of mechanisms for moving each of said slats between said first and second position;
- a controller for regulating movement of each of said slats between said first and second position in accordance with a predetermined program;
- wherein said cushion has a thickness T, a width W, a stiffness S, a maximum compression C and a recovery rate R, said thickness T and stiffness S being selected to allow said cushion to conform to the lower body region of the immobilized person to provide support therefor while minimizing an initial seating pressure Pi, and wherein said displacement D exceeds said maximum compression C, said maximum compression C being a function of thickness T, stiffness S and the body weight of the immobilized person;
- and wherein said recovery rate R of said cushion is no greater than said predetermined relief period.
3 more elements
A method of retrofitting a wheelchair, comprising the steps of:
- removing an existing seat of the wheelchair;
- providing a seating apparatus for supporting a lower body region of an immobilized person for avoidance and relief of decubitus ulcers, the seating apparatus providing regular intervals of seating pressure reduction below a predetermined seating pressure for at least a predetermined relief period, said seating apparatus comprising:
- a plurality of rigid slats, said slats defining a support plane for supporting the lower body region of the immobilized person, each of said slats being movable between a first support position wherein each of said slats is coplanar with said support plane and a second displaced position wherein each of said slats is displaced a distance D from said support plane for the predetermined relief period whereby capillary blood pressure is reduced below the predetermined seating pressure in the unsupported portion of the lower body region, and wherein each of said slats supports a cushion for sitting thereon, said cushion being formed from a viscoelastic material;
- a cage for supporting said slats and configured to allow movement of each of said slats between said first and second position;
- a plurality of mechanisms for moving each of said slats between said first and second position;
- a controller for regulating movement of each of said slats between said first and second position in accordance with a predetermined program;
- wherein said cushion has a thickness T, a width W, a stiffness S, a maximum compression C and a recovery rate R, said thickness T and stiffness S being selected to allow said cushion to conform to the lower body region of the immobilized person to provide support therefor while minimizing an initial seating pressure Pi, and wherein said displacement D exceeds said maximum compression C, said maximum compression C being a function of thickness T, stiffness S and the body weight of the immobilized person;
- and wherein said recovery rate R of said cushion is no greater than said predetermined relief period;
- adjusting said stiffness S and said thickness T of the cushion to reduce the initial seating pressure Pi while ensuring said displacement D exceeds said maximum compression C whereby the seating pressure is reduced to a pressure below 32 mm Hg during displacement of each of said slats;
- and
- installing said seating apparatus within the existing wheelchair.
8 more elements
A method of treating decubitus ulcers, comprising:
- providing a chair having a seating apparatus for supporting a lower body region of an immobilized person for avoidance and relief of decubitus ulcers, the seating apparatus providing regular intervals of seating pressure reduction below a predetermined seating pressure for at least a predetermined relief period, said seating apparatus comprising:
- a plurality of rigid slats, said slats defining a support plane for supporting the lower body region of the immobilized person, each of said slats being movable between a first support position wherein each of said slats is coplanar with said support plane and a second displaced position wherein each of said slats is displaced a distance D from said support plane for the predetermined relief period whereby capillary blood pressure is reduced below the predetermined seating pressure in the unsupported portion of the lower body region, and wherein each of said slats supports a cushion for sitting thereon, said cushion being formed from a viscoelastic material;
- a cage for supporting said slats and configured to allow movement of each of said slats between said first and second position;
- a plurality of mechanisms for moving each of said slats between said first and second position;
- and
- a controller for regulating movement of each of said slats between said first and second position in accordance with a predetermined program;
- sitting an immobilized person on said seating apparatus, said person having a decubitus ulcer on a lower body region thereof, said seating apparatus having a front side and a back side;
- moving on an individual basis each of said slats from said first position to said second position in a sequential direction extending from said front side to said back side whereby blood flow is stimulated in said lower body region.
5 more elements
Dependencies are inferred from the claim text.