Multi-section Variable Density Mattress

Abstract

A mattress possessing particular utility in hospitals and nursing homes reduces the incidence and severity of bed sores, improves muscle tone and reduces back ache. The mattress features plural sections of foam whose densities and degrees of compressibility vary, so that regulated pressures will be applied to different sections of the body for maximum comfort. The mattress may be turned to change the pressure points on the body periodically as the need arises. The mattress is employed in conjunction with a foam padded base or underlay having a relatively rigid component.

Parent Case Text

This application is a continuation in part of application Ser. No. 233,687 filed on the 10th day of March, 1972, now abandoned.

Description

BACKGROUND OF THE INVENTION

A definite need exists for an improved bed mattress particularly in hospitals and nursing homes where some patients are confined to the bed for long periods of time. Also in the home, certain individuals with chronic back complaints experience the need for a mattress which would tend to ease such complaints.

The prior art contains quite a number of teachings pertaining to sectional mattresses and mattresses having variable density compoents but none of these prior art structures has proven to be completely satisfactory in terms of satisfying the above needs of bedridden hospital and nursing home patients, in particular.

Accordingly, the main objective of the invention is to provide a mattress which is constructed to meet the needs of the art more completely than any known prior art proposal. In accordance with the invention, a multi-section mattress includes variable density components to support the head, shoulders, back, hips and heels with varying degrees of pressure on these parts of the body to promote maximum comfort and to minimize the occurrence and severity of decubitus ulcers or bed sores. In furtherance of this objective, the mattress is employed in conjunction with and above a base which is additionally padded with foam and the base is constructed in sections so as to be compatible with standard articulated hospital type beds. The base may be one piece or continuous for use upon a conventional home bed.

Other features and advantages of the invention will become apparent during the course of the following detailed description, and among these features are the economy of construction of the mattress and base, comparable to the cost of a good-quality hospital mattress and the durability of the composite mattress and foundation which will last many years beyond the life of a conventional high quality hospital mattress.

BRIEF DESCRIPTION OF DRAWING FIGURES

FIG. 1 is an exploded perspective view of a mattress and foundation therefor embodying the invention shown in association with a conventional hospital bed.

FIG. 2 is an enlarged longitudinal vertical section through the mattress and foundation taken on line 2--2 of FIG. 1.

FIG. 3 is a greatly enlarged fragmentary vertical section through the mattress and foundation taken on the plane of FIG. 2.

FIGS. 4 and 5 are diagrammatic perspective views showing a comparison of the invention and the prior art.

DETAILED DESCRIPTION

Referring to the drawings in detail wherein like numerals designate like parts, the numeral 10 designates a sectional variable density mattress in its entirety having a suitable fabric envelope or cover 11. This mattress embodies a head support block or slab 12 of an open cell compressible foam plastic, such as foam polyurethane. In a typical embodiment, the head slab 12 is 36 inches wide by 12 inches long and 6 inches thick. While these dimensions are not extremely critical, they are the most desirable dimensions. However, they may be varied in some cases. The preferred density of the foam employed in the head slab 12 is approximately 1.75-1.85 lbs. per cubic foot. The compressibility of the slab 12 to a thickness of about 4 inches from the relaxed thickness of 6 inches can be expressed in terms of 24-30 lbs. loading on the entire upper surface of the slab.

The midsection of the mattress 10 which supports the shoulders and back of the user is composed of two superposed slabs 13 and 14, each of which measures 36 inches wide by 44 inches long in the embodiment shown and each of which is formed of open cell foam polyurethane or equivalent material. The upper slab 13 is preferably 4 inches thick and the lower slab is 2 inches thick. The density of the upper slab is from 2.2-2.4 lbs. per cubic foot, and the density of the lower slab 14 is from 1.75-1.85 lbs. per cubic foot. The compressibility of the upper slab 13 in the same terms specified for the slab 13 is approximately 38-50 lbs. and for the lower slab 14 is approximately 24-30 lbs.

The mattress 10 further embodies a foot section or slab 15 of the same foam plastic material measuring 36 inches wide by 24 inches long by 6 inches thick. The particular foam used for the foot slab 15 preferably has a density of from 1.75-1.85 lbs. per cubic foot and a compressibility of 24-30 lbs. in the same terms expressed above for the other sections, namely the load necessary on the entire area of the slab to compress a 6 inch slab approximately 2 inches.

It may be seen that the composit mattress 10 contains regions or zones which differ in density and compressibility and each zone is therefore capable of exerting a specifically different pressure or resistance on a particular part of the anatomy of the user. With the mattress positioned as in FIG. 2 and the head of the user adjacent to the slab 12, the mattress will possess a first supporting capability. It may be seen that if the mattress is reversed head-to-foot, or if it is inverted, a second or new set of resistance values will be provided and this is sometimes beneficial in relieving the monotony to the patient and in changing the degrees of pressure on different parts of the body, which in turn can help relieve bed sores, fatigue and back ache. The mattress as constructed, therefore, is very versatile.

In an alternate embodiment of the invention, a mattress was constructed in which the density of the foam employed in the head slab 12 is approximately 1.6-1.75 lbs. per cubic foot. The compressibility of the slab 12 to a thickness of about 4 inches from the relaxed thickness of 6 inches can be expressed in terms of a 23-29 lb. loading on the entire upper surface of the slab. The slab 12 is 36 inches wide and 18 inches long.

The midsection of the mattress 10 which supports the shoulders and back of the user is composed of two superposed slabs 13 and 14, each of which measures 36 inches wide by 33 inches long in the embodiment shown and each of which is formed of open cell foam polyurethane or equivalent material. The upper slab 13 is preferably 4 inches thick and the lower slab is 2 inches thick. The density of the upper slab is from 2.6-2.75 lbs. per cubic foot, and the density of the lower slab 14 is from 1.6-1.75 lbs. per cubic foot. The compressibility of the upper slab 13 in the same terms specified for the slab 13 is approximately 45-55 lbs. and for the lower slab 14 is approximately 23-29 lbs.

The mattress 10 further embodies a foot section or slab 15 of the same foam plastic material measuring 36 inches wide by 30 inches long by 6 inches thick. The particular foam used for the foot slab 15 preferably has a desnity of from 1.6-1.75 lbs. per cubic foot and a compressibility of 23-29 lbs. in the same terms expressed above for the other sections, namely the load necessary on the entire area of the slab to compress a 6 inch slab approximately 2 inches.

It had been further determined that the head slab 12 may have a range of densities of from 1.4-1.55 to 2-2.2 lbs. per cubic foot. The slab 12 may have a range of compressibility in the same terms as expressed above of from 22-38 lbs. per cubic foot. The range of the density of the upper slab 13 if from 2.2-2.4 to 2.8-2.9 lbs. per cubic foot. The range of compressibility for slab 13 is from 30-60 lbs.

The range of density and compressibility of slabs 14 and 15 is the same as the figure given for slab 12 above.

An important feature of the invention resides in the provision of a foundation or base 16 to be used in conjunction with the mattress 10. This base 16, when used in conjunction with a hospital bed 17 such as the well-known Joerns hospital bed, is formed in sections which correspond in length to the articulated sections 18, 19 and 20 of the bed 17 and to the intermediate fixed section 21. Correspondingly, the foundation 16 has sections 22, 23, 24 and 25, as shown. These sections have the same width as the mattress 10 and the same overall length, the individual foundation sections being formed lengthwise to fit the several sections of the hospital bed.

Each foundation section 22 through 25 includes a preferably 1/2 inch thick plywood underlay 26, 27, 28 and 29 immediately above which is a preferably 2 inch thick slab 30, 31, 32 and 33 of foam polyurethane or the like having a density of about 2.5 lbs. per cubic foot and a compressibility of 20-30 lbs. on the basis described for the mattress components. Thus, it may be seen that the foundation padding is somewhat softer and more readily compressible than the softest sections of the mattress proper. However, when the mattress is placed upon the foundation 16 for use, the composite assembly which represents the total invention gives a different effect than would be achieved if the mattress alone were used without the foundation, or if it were used with a different type of foundation, such as a felt pad or some sort of box spring. In the total assembly, the foundation foam slabs or pads supplement and add to the net supportive effect of the mattress in such a way as to produce the greatest comfort and beneficial effect for the user or patient. The several sections of the foundation 16 are preferably enclosed in individual covers or envelopes 34, 35, 36 and 37, as shown.

To further emphasize the mertis of the invention in comparison to conventional extra firm solid mattresses, medium firm and regular hospital mattresses, a comparison chart is shown below. In this chart, the pressures exerted on different parts of the body are indicated in millimeters of mercury.

__________________________________________________________________________ Invention MattressAll Units on Invention Foundation: Head Shoulders hl,25 Lumbar Hips Heel __________________________________________________________________________ Extra Firm S-ide 37 44 50 58 32 Medium Firm S-ide 31 36 42 51 26 Extra Firm Side 34 39 54 56 34 Reversed Head to Foot Medium Firm Side 34 37 40 54 24 Reversed Head to Foot All units tested withut foundation increased pressures by approximately 3 to 5 mm. of Hg. Extra Firm Solid Mattress One Side 31 46 56 65 30 Repositioning and turning mattress--reading remains the same. Medium Firm Solid Mattress tc,19 One Side 35 47 48 53 35 Repositioning and turning mattress--read-ing remains the same. Regular Hospital Mattress One Side 43 52 58 68 35 Repositioning and turning mattress--reading remains the same. __________________________________________________________________________

The figures in the above chart are the results of a test using as a subject a 6 foot tall, 185 pound person. Quite naturally, the test results will differ for each person and in this respect it is to be understood that the invention is capable of automatically compensating to produce the most advantageous supportive pressure on any person or body of sufficient adult size to span the mattress. The figures in the comparison chart demonstrate that the mattress, when utilized properly with the foundation 16, exerts the minimum unit pressures on the various parts of the anatomy and these pressures are significantly lower than the corresponding pressures exerted by the conventional and hospital mattresses. The test results also show that the parts of the anatomy requiring the greatest degree of support, namely the back and hips, receive this support with the invention and the parts requiring lesser supporting pressure, namely the head and heels, are properly accommodated.

With reference to FIG. 4, a prior art solid mattress such as a regular hospital mattress is illustrated and it will be observed how the body of the user depresses the prior art mattress unevenly due to the fact that the mattress is unable to compensate for the different weight regions of the body. FIG. 5, on the other hand, shows the invention with its different density and compressibility zones enabling the mattress and foundation assembly to support the body without extreme deformation, the assembly automatically exerting the necessary unit pressures on the different regions of the body with the necessary differential to allow even support along the full length of the body and minimum mattress compression or deformation.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.

Claims

I claim:

1. A mattress made of foam having three distinct sections, said distinct sections being integral and coextensive with each other, said foam material of the first zone having a first density and compressibility factor at 4 inches in the order of 22 to 30 lbs. per cubic foot, said second zone being adjacent to said first zone and having a second density and second compressibility factor, said second zone having a first and second portion, said first portion having a compressibility factor at 4 inches in the order of 37 to 60 lbs. per cubic foot, and said third zone adjacent to said second zone and having a third density and compressibility factor at 4 inches in the order of 22 to 30 lbs. per cubic foot, and said second portion of said second zone having a compressibility factor at 4 inches in the order of 22 to 30 lbs. per cubic foot.

2. The mattress of claim 1, in which the material of first zone and third zone have identical density and compressibility factors different from that of the second zone in the order of 1.4-2.2 lbs. per cubic foot said density of said first portion of said second zone being in the order of 1.85-2.9 lbs. per cubic foot, whereby the various densities and compressibility factors of said foam cooperate to form a mattress having therapeutic support qualities to the users thereof.

3. A mattress made of foam having three distinct sections, said distinct sections being integral and coextensive with each other, said foam material of the first zone having a first density and compressibility factor at 4 inches in the order of 23 to 30 lbs. per cubic foot, said second zone being adjacent to said first zone and having a second density and second compressibility factor, said second zone having a first and second portion, said first portion having a compressibility factor at 4 inches in the order of 38 to 55 lbs. per cubic foot, and said third zone adjacent to said second zone and having a third density and compressibility factor at 4 inches in the order of 24 to 30 lbs. per cubic foot, and said second portion of said second zone having a compressibility factor at 4 inches in the order of 23 to 30 lbs. per cubic foot.

4. The mattress of claim 3, in which the material of first zone and third zone have identical density and compressibility factors different from that of the second zone in the order of 1.6-1.85 lbs. per cubic foot said density of said first portion of said second zone being in the order of 2.2-2.75 lbs. per cubic foot, whereby the various densities and compressibility factors of said foam cooperate to form a mattress having therapeutic support qualities to the users thereof.

5. A mattress made of foam having three distinct sections, said distinct sections being integral and coextensive with each other, said foam material of the first zone having a first density and compressibility factor at 4 inches in the order of 23 to 29 lbs. per cubic foot, said second zone being adjacent to said first zone and having a second density and second compressibility factor, said second zone having a first and second portion said first portion having a compressibility factor at 4 inches in the order of 45 to 55 lbs. per cubic foot, and said third zone adjacent to said second zone and having a third density and compressibility factor at 4 inches in the order of 23 to 29 lbs. per cubic foot, said second portion of said second zone having a compressibility factor at 4 in the order of 23 to 29 lbs. per cubic foot, and said material of first zone and third zone having identical density and compressibility factors different from that of the second zone in the order of 1.6 to 1.75 lbs. per cubic foot, said density of said first portion of said second zone being in the order of 2.6 to 2.75 lbs. per cubic foot, whereby the various densities and compressibility factors of said foam cooperate to form a mattress having thereapeutic support qualities to the users thereof.