DESCRIPTION

BOLSTERED MATTRESS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority U.S. Patent Application Serial No. 11/788,196 filed April 19, 2007, the entire disclosure of which is specifically incorporated herein by reference. Technical Field

This invention relates to beds, such as hospital or medical/surgical beds, and mattresses for such beds.

BACKGROUND OF THE INVENTION Hospital beds or medical/surgical beds are used by patients during a hospital stay, and are also employed for in-home care. A typical hospital bed has a bed frame and a mattress positioned upon the bed frame. The bed frame usually has bilateral side rails positioned on the upper and lower portion of the bed frame that are designed to keep mentally or physically impaired patients from accidentally rolling off of the bed and falling on the floor, possibly resulting in an injury to the patients. The side rails can be positioned in an up position, where they block patients from rolling off the bed, or positioned in a down position that allows patients freedom to enter or exit the mattress arranged upon the bed frame.

Unfortunately, the design of the hospital bed does not prevent and, in fact, contributes to other injuries to a certain group of patients, for example patients with pre-existing conditions such as altered mental status (organic or acquired), confusion, restlessness, or lack of muscle control.

Summary of the Invention In one aspect, a medical bed has a frame with a mattress support surface and a mattress supported on the support surface. In another aspect, a mattress is designed for use in conjunction with a medical/surgical bed frame, which has a surface for receiving the mattress. The mattress has a central portion with an upper surface adapted to support a patient's body and a lower surface that interfaces with

the support or receiving surface of the frame. The mattress has a right and left side bolster disposed on opposite sides of the central portion, such that each bolster extends above the upper surface. Each bolster defines a recess of reduced bolster height in relation to the upper surface of the central portion of the mattress. A mattress cover extends about the central portion and both bolsters such that the mattress and the cover together form a single mattress assembly.

One or more of the following features may also be included. A side rail mounted on the frame and a control panel mounted on the side rail. In some embodiments, the recess is positioned to enable the patient to access the control panel. In other embodiments, the recess can be sized and positioned to enable the patient ingress and egress to and from the upper surface. The central portion and the bolsters are formed of foam. The left and right bolsters have upper surfaces flush with the upper surface of the central portion at the recesses. The central portion includes a head section, a body section, a foot section, and a top section, which covers the head, body and foot sections. The foot section has a thickness that decreases with distance from the body section. The foam for each section has a shape, a density and an indentation load deflection (ILD) selected to inhibit formation of pressure sores on the skin of the patient. (A piece of foam can be described in terms of its density and it's ILD. The density of the foam is the mass per unit of volume, typically pounds per cubic foot of foam. The ILD refers to the amount of force, in pounds, required to compress or indent, using a 50 inch disc, a piece of foam measuring 15 in. wide, 15 in. long, and 4 in. high to 75% of its unloaded thickness (or height), and is an indication of firmness). The foam for each bolster has a shape, a density, and an ILD selected to provide a passive reminder to the patient of a lateral edge of the mattress, for example the density of the foam bolster can be 1.8 PCF and the ILD can be 50.

These general and specific aspects may be implemented using a system, a method, or a combination thereof.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

Brief Description of the Drawings

FIG. 1 shows a raised foam perimeter mattress on a hospital bed frame with a cutout section of the raised foam perimeter aligning with the center of the bed between upper and lower side rails;

FIG. 2 shows the raised foam perimeter mattress on the hospital bed frame with the cutout section aligning with a control panel on an upper side rail of the bed frame;

FIG. 3 is a view of the raised foam perimeter mattress being positioned on a hospital bed frame, showing the surface that the mattress rests upon;

FIG. 4 is an exploded view of components of the raised foam perimeter mattress;

FIG. 5 is a view of the mattress components assembled and a cover about the mattress components in the process securing a top cover to a bottom cover by using a zipper;

FIG. 6A is an end view of a side bolster angularly tapering from a planar surface of the mattress;

FIG. 6B is an end view of a side bolster radially tapering form a planar surface of the mattress.

Like reference symbols in the various drawings indicate like elements.

Description of the Preferred Embodiments

Referring to Fig. 1-3, a hospital bed 10, which can be used in the medical, surgical, psychiatric, and extended care setting, is shown. Typically, the bed 10 has a frame 12, with one or more side rails 13 (usually four side rails), and a mattress 11. One or more of the side rails 13 can have controls on the side rail for controlling such things as a television, or the bed itself, i.e. adjusting the bed height, or raising or lowering the head or foot of the bed, etc. The side rails 13 can be positioned in at least a raised or lowered position, the respective positions either preventing a patient from falling out of the bed or allowing the patient to enter or exit the bed 10.

As seen if Figure 3, the bed 10 has a mattress receiving surface 31 upon which the mattress rests when placed on the bed frame. This surface can be any type of surface that provides support for the mattress 11. Referring to Fig. 1-3, mattress 11 sits on top of mattress receiving surface 31 between a headboard 18 and a footboard 17, although bed 10 may be provided without either or both the

headboard or the footboard. The side rails 13 when raised are positioned on opposite sides of the mattress 11 , such that mattress 11 sits between the opposite side rails.

Mattress 11 has bilateral raised sides 16. These raised sides/bolsters 16 extend above a non-raised surface of the mattress by between 1-6 inches, for example 2 inches. The raised sides 16 thus provide a boundary on opposite sides of the mattress serving as a passive reminder to the patient as to the lateral extent of the mattress. The raised sides 16 abut the lateral edge of the central portion 19 (the central portion 19 being shown in Fig. 1 as extending between the two raised sides 16 with the letter "w"), or non-raised portion of the mattress, and extend laterally beyond the lateral edge of the central portion by between 1-5 inches, for example 4.5 inches. In some embodiments, the raised sides 16 are constructed of materials such that the patient notices, in addition to the change in height, a change in firmness (i.e. density and ILD) of the raised sides. The firmness, although typically greater, can be either greater or less than the firmness of the central portion 19 of the mattress, providing a passive reminder, along with the height difference, to the patient of the proximity of a lateral edge of the mattress. Each raised side 16 has a cutout section 15 such that the height of the upper surface of cutout section 15 is diminished from the height of the top surface of the remainder of the raised side. In some embodiments, the height of the cutout section 15 is essentially the same as the height of the surface of contiguous non-raised or central portion 19 of the mattress. Although the height of the cutout section 16 is similar to the non-raised portions of the mattress, the firmness is essentially the same as the remainder of the raised sides 16 such that the patient is still alerted to the approach of the lateral edge of the mattress 11.

As can be seen in Fig. 1-2, the cutout section 15 can be alternatively placed, during production, in any position between the head and foot of the mattress 11. In some embodiments as shown in Fig. 1 , the cutout section is placed in a central position of the mattress, such that the cutout section 15 is essentially between the upper and lower side rails allowing the patient ingress and egress to the mattress area when one or both of the side rails on a side are in the raised position, if the positioning of the side rails on the bed frame allows enough space to permit the patient to get into and out of the bed. Even if the side rails 13 do not permit the patient to get into and out of the bed when the side rails are in the raised position,

the cut out section 15 can be positioned in a position that allows the patient easier ingress and egress from the mattress when the side rails are down.

In other embodiments as shown in Fig. 2, the cutout section 15 can be placed in a position corresponding to the position of one or more control panels on the side rails. When the cutout section 15 is in this position, the patient can access the controls with the side rails in the raised position. One or both upper side rails may have controls that can be accessed by the patient through the cutout sections on opposite sides of the mattress, for example one side may have controls for the bed to change the bed position, and the other side may have controls for an in room television. In other embodiments, the cutout section 15 is positioned such that a caregiver has better access to one or more areas of the patient's body.

The length "I" of cutout section 15 (see Fig. 1 ) can vary in the range of about 12 to 24 inches, for example 18 inches. The length may be of such dimensions as to allow a person to enter and exit the bed or, if positioned for control panel access, to allow access to the control panels.

Depending on the bed frame, raised sides 16 can also be configured (height and firmness) to help ameliorate potential entrapment areas of the bed 10. For example, the raised sides 16 can be configured to make access the area between the side rails 13 and the mattress more difficult. Moreover, the bed 10 can be used with the side rails down for some patients because raised sides 16 serve as a passive reminder of the lateral extent of the mattress without creating possible entrapment areas for the patient. This also removes the need for the patient to climb over the side rails or the foot of the bed when entering or exiting the mattress at night if they cannot lower the side rails. Mattress 11 is constructed in such a way that, in addition to the raised sides

16 providing a passive reminder to the patient about the lateral extent of the mattress, mattress 11 provides a surface that helps to reduce the chance of a bed ridden patent developing ischemic ulcers of the skin. The mattress 11 has a pressure-relieving surface that redistributes the pressure on the patient's skin reducing ischemic injury and ulcer formation. The mattress has one or more components made out of a foam material or similar material that are secured together, for example by gluing, and covered with a mattress cover.

The foam material can be made from polyurethane foam, memory foam, polypropylene foam or latex foam, for example polyurethane foam. The glue can be

n-propyl bromide based adhesives, water based spray adhesives (such as Simalfa™ liquid spray adhesive), and hot melt spray adhesives, for example hot melt spray adhesives. The foam can have a density of between 1.4 to 4.0 pounds per cubic foot ("PCF") of foam, and an ILD of between 10 to 50. By selecting a density and ILD of the foam components, the properties of each component can tailored to a particular part of the anatomy that the section supports. Therefore, the foam supporting the torso can have a different density and ILD than the foam supporting the head or the distal extremities, thus providing greater comfort and support. The foam can be cut under certain anatomic zones, such as the ischium, heels, sacrum, shoulder, or torso in general, to help protect against pressure and shearing that can contribute to ischemic ulcers of the skin. Also, a section of the mattress supporting the feet can be sloped, such that the height of the mattress decreases distally, relieving pressure on the heels. Although described as being made of a foam material, the mattress components can be made out of any other material having similar support and pressure distribution properties.

Referring to Fig. 4, the non-raised surface or central portion 19, which is sandwiched between the raised sides16 has one or more components. The components are chosen to provide a mattress surface that not only helps to prevent ischemic ulcers from developing on the patient, but also to provide a comfortable surface for the patient using the bed. In some embodiments as shown in Figure 4, there are four components forming a central portion 19 of the mattress 11 in addition to a right (as seen from the foot of the mattress) foam side rail/bolster 43 and a left foam side rail/bolster 46 that form the raised sides 16. There is a top section 41 that provides a uniform upper surface overlying a head section 42, a body section 44, and a foot section 45. These sections and the right and left side rails are secured together, for example by gluing, and covered with a cover 51 (shown in Fig. 5). The components are described in the following paragraphs. The dimensions and physical properties of the foam components described in the following paragraphs are exemplary and it should be understood that other dimensions, physical properties (such as density and ILD), and even number of components are within the scope of this disclosure.

Referring to Fig. 4, the head section 42 is twenty-seven inches in width, seven inches in length, and four and one-half inches in height. The head section 42 has a density of 1.8 PCF and an ILD of 33. The head section is less firm than the body

section. The body section 44 is twenty-seven inches in width, twenty-seven inches in length, and four and one-half inches in height. The body section 44 has a density of 2.5 PCF and an ILD of 45. In some embodiments, the body section has notches or compression channels in the surface of the foam under anatomic zones that can help protect against pressure and shearing, for example 18 notches across the width of the body section starting 2 7/8 inches from the head end of the body section and spaced every 2.75 inches. The notches can be between 1/2 to 2 inches in height, for example 3/4 inch in height, and between 1/8 to 3/4 inches in width, for example 1/4 inch. The head section 42 and the body section 44 form a planar surface of 4.5 inches in height. The foot section 45 is 27 inches in width and 7 inches in length and has a density of 1.8 PCF with and ILD of 33. The foot section 45 can have either a uniform height or a tapered height in a distal direction. In some embodiments, the foot section 45 tapers in height distally from 4.5 inches in height where the foot section abuts the body section 44 to three inches in height at the distal edge of the mattress. In other embodiments, the foot section is not tapered in height and forms a planar surface with the head and body sections and has a uniform height of 4.5 inches.

The head section 42 and foot section 45 are glued to the body section 44 as shown in Fig. 4. The top section 41 is glued to the top surface of these three components presenting a seamless top surface on the central portion 19 of the mattress 11. The top section 41 is 27 inches in width and 80 inches in length and 2.5 inches in height. However, the dimensions of the top section can be changed if the dimensions of the underlying components are changed, such that the top section covers the underlying components. In some embodiments, the top section 41 is made of viscoelastic foam and has a density of 4.0 PCF and an ILD of 10. In other embodiments, the top section 41 is made of shaved convoluted foam and has a density of 2.5 PCF with an ILD of 27. The shaved convoluted foam has a base thickness of 1.5 inch and a thickness of one inch in the valley.

Again referring to Fig. 4 right side rail/bolster 43 and a left side rail/bolster 46 forming the raised sides 16 are glued to the right and left sides, respectively, of the remaining components. Although the components are described as being glued together, any method of attachment that secures the components to one another can be used, such as hook and loop fasteners or using interlocking cuts. The bolsters are nine inches in height and 4.5 inches in width and 80 inches in length. In some

embodiments the bolsters are rectangular in height and width. In other embodiments, the portion of the side rails 43, 46 extending above the upper surface of the central portion 19 have a non-rectangular shape. When viewed from end on, the side bolster can be either curved (Fig. 6B) or angular (Fig. 6A) in its transition from the planar surface of the central portion 19 to the top surface of the side bolster 16. The cutout section can be positioned in a desired location on the side bolsters 16 corresponding to the controls on the bed frame sides rails, or corresponding to a location making ingress and egress easier, or a position making access to a certain parts of the patient easier. The bolsters have a density of 1.8 PCF per cubic foot and an ILD of 50. The cutout section has a similar density and ILD. The increased height and ILD of the bolster serves to remind the patient that the lateral edge of the mattress is approaching. In other embodiments, the dimensions, density, and ILD of the side rails 43, 46 can be altered as long as the side rails provide the passive reminder of the lateral extent of the mattress. Referring to Fig. 5, once the components are assembled into a single mattress unit, a mattress cover 51 is applied. In some embodiments, the mattress cover 51 covers at least the upper surface of the mattress assembly. In other embodiments, the mattress cover 51 covers the entire surface of the mattress assembly. For example, the mattress cover 51 can have a top section 54 and a bottom section 55. The top section 51 fits over the top surface of the mattress 11 and the bottom section 55 fits over the bottom surface to mattress 11. The top and bottom sections 54, 55 extend over the sides of the mattress 11 and are fixedly engaged with one another. This engagement can be permanent, for example by using glue or by sowing the edges together, or temporary, for example by using hook and loop fasteners or, as shown in Fig. 5, a zipper 56. In some embodiments the top and bottom sections are made out of the same material such as neoprene/butyl rubber coated nylon. In other embodiments, the top and bottom sections 54, 55 are made of different materials, for example the material of the top section can be selected to reduce staining, i.e. moisture and vapor transmission, and to facilitate cleaning and disinfecting, for example butyl rubber coated nylon or cast-coated polyurethane or polyester blend, while the bottom section can be made from a material that keeps the mattress 11 from sliding on the mattress receiving surface 31 , such as 8-12 ounce vinyl, for example 10 once vinyl, or a reverse grip institutional healthcare fabric, such as SOFFTICK™.

The size and shape of mattresses 11 and the components can be customized to fit the wide variety of hospital bed frames currently manufactured. The assembled mattress is placed upon the mattress supporting surface 31 of the hospital bed frame. Thus, a hospital bed with the mattress having a raised foam perimeter containing a cutout section that can provide access to controls on the side rails of the bed frame, or access for the patient to the mattress, and/or access to the patient for the caregiver is provided.

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.