Patent Publication Number: US-2005115003-A1

Title: Internal contour foam mattress

Description:
BACKGROUND OF THE INVENTION  
      This invention relates to beds and, more particularly, to improved mattresses for beds that enhance the quality of sleep.  
      Normally, everyone spends a large percentage of everyday sleeping and the quality of sleep is important to a person&#39;s good health and enjoyment of life. Comfortable mattresses are important in establishing restful sleep. During sleep, a healthy person typically passes through five levels of sleep which include stages I-IV and which additionally includes a REM (Rapid Eye Movement) sleep stage. Stages I and II are the lightest sleep and stages III and IV are the deepest. The REM stage is that level in which sleepers dream and receive the mental health benefits attendant to dreaming. All levels of sleep are important, but stages III and IV are the deepest and most physically restful sleep, when, for example, human growth hormone is secreted. Normal sleep is cyclic passing through the stages from I to IV and back from IV to I and into and out of REM. This sleep cycle is repeated a number of times over a normal sleep period, but can be disrupted due, for example, to body discomfort.  
      Restfulness and the quality of sleep are dependent upon the comfort of sleepers. When sleepers become uncomfortable, they move to relieve the discomfort and the resulting moves are a normal part of sleep. When sleepers move, they frequently change to lighter levels of sleep (stage I or II) or awaken. The more discomfort sleepers feel, the more they will move and the more time they will spend in lighter and less restful sleep. Good sleeping is normally associated with a low number of body shifts during the sleep period. Bed-induced shifts due to discomfort caused by the bed are a significant cause of poor sleep quality. On conventional mattresses (including feather beds, inner spring mattresses, orthopedic mattresses, waterbeds and the like), most people experience about forty major postural body shifts in the course of a night&#39;s sleep. Poor sleepers experience about sixty percent more major shifts than good sleepers. While some shifts during a sleep period are sixty percent more major shifts than good sleepers. While some shifts during a sleep period are beneficial, the quality of sleep can be greatly improved for many by reducing the number of bed-induced shifts.  
      There are two major causes of bed-induced shifting that cause poor sleep. The first major cause of shifting is the buildup of pressures on parts of the body and the second major cause of shifting is poor body alignment. Considering the first major cause of shifting, the buildup of pressures results from prolonged lying in the same position. On conventional mattresses, the pressure tends to be greatest on the body&#39;s protrusions (such as shoulders and hips) where body tissues are put in high compression against the mattress. High compression tends to restrict capillary blood flow which is recognized by the body, after a period of time, as discomfort. The amount of pressure which causes a discontinuance of capillary blood flow is called the ischemic pressure. The ischemic pressure threshold is normally considered to be approximately thirty mmHg. The discontinuance of capillary blood flow is observable as a red spot on the skin. After pressure is applied, a red spot on the skin is a precursor to tissue damage. When parts of the body (usually shoulders and hips in conventional mattresses) are subjected to pressures above the ischemic threshold, discomfort results and, hence, a person shifts to remove the discomfort and threat to tissue damage.  
      Considering the second major cause of shifting, poor body alignment results from lateral bending of the vertebral column of the body, particularly for a person in a side-sleeping position. Such lateral bending is typically caused by mattresses that allow sagging of the body. Conventional mattresses allow such sagging regardless of the hardness or the softness of the mattress but the sagging effect tends to be more pronounced on soft mattresses. A sagging mattress allows the waist to drop relative to the rib cage and hips and results in stress to muscles, tendons and ligaments. The stress from a sagging mattress frequently manifests as discomfort or even pain in the lumbar region of the back. Such discomfort causes the sleeper to shift in order to relieve the discomfort.  
      In U.S. Pat. No. 4,662,012 invented by Torbet, one of the inventors herein, an air mattress is disclosed for supporting a person in a reclining position while maintaining spinal alignment and while maintaining low supporting body surface pressure. The Torbet mattress utilized zones running laterally across the width of the mattress with differing air pressures in the zones longitudinally along the length of the mattress. The Torbet mattress has proved to be ideal for supporting sleepers while minimizing supporting body surface pressure and maintaining spinal alignment.  
      While the Torbet mattress has established a standard of comfort that has not been achieved by conventional mattresses, the Torbet mattress has not been distributed as widely as possible because of its high cost of manufacture. The superior benefits of the Torbet mattress have generally been available only to those, such as hospitals, sleep clinics and the wealthy, willing to pay a high price.  
      For the Torbet mattress and mattresses in general, persons of greater body weight tend to sink farther into and depress the mattress more than persons of lower body weight. Body protrusions (such as shoulders and hips) cause the highest depression of the mattress and need to be accommodated. The shoulder of a heavy body resting atop the mattress in a side-lying position should not bottom out, that is, the shoulder should not depress the mattress to the extent that an underlying hard supporting surface is felt.  
      Mattresses using foam and spring sections have been proposed to reduce the cost of the Torbet mattress. Foam or spring sections alone in mattresses, because of the vertical displacement properties of conventional foams and springs, have not satisfactorily achieved simultaneously spinal alignment and uniform low supporting body surface pressure along the interface between the mattress and the body.  
      An ideal mattress has a resiliency over the length of a body reclining on the mattress to support the body in spinal alignment, without allowing any part of the body to bottom out, and also has a low surface body pressure over all or most parts of the body in contact with the mattress. Since a reclining body has both varying density and varying contour in the longitudinal direction, the ideal mattress must conform to these variations. With such variations, in order to achieve spinal alignment, the supporting forces in the mattress, under load from the reclining body, must vary along the body to match the varying body density and shape. Also, when the body is in spinal alignment, for an ideal mattress, the supporting pressures in the mattress against the skin must be low. The preferred pressure against the skin of a person in bed for an ideal mattress is generally below the ischemic threshold. The preferred side-lying spinal alignment for a person in bed is generally defined as that alignment in which the spine is straight and on the same center line as the legs and head.  
      While the general principles of an ideal mattress have been recognized since the Torbet mattress, actual embodiments of mattresses that approach the properties of an ideal mattress at reasonable costs not have been forthcoming. Lateral zones, with varying compression in the longitudinal direction, of springs in spring mattresses are capable of achieving spinal alignment if the mattress is of sufficient depth to allow the shoulders and hips to sink into the mattress to a depth that maintains spinal alignment without bottoming out. However spring mattresses generally do not achieve spinal alignment for the primary reason that the compression forces in springs vary as a function of the vertical depression of the springs in compression. The taller the spring in the relaxed state, the greater is the vertical depression and compression of the spring before the force increases to balance the weight of the part of the body lying on the spring. Thus, a body can sink farther into a tall, weak spring before the weight of the body is balanced than it can sink into a short, firm spring. Although tall, weak compression springs are desirable for reducing body pressure, they tend to have intolerable lateral instability and other problems that result in uncomfortable mattresses.  
      Conventional single-layer spring mattresses with uniform springs are generally unable to provide the qualities necessary for an ideal mattress. In a two-layer structure, the spring compression rate is decreased if one compression spring in one layer is mounted atop another compression spring in another layer. U.S. Pat. No. 5,231,717 used the two-layer structure in multiple zones extending laterally, with different firmness in zones in the longitudinal direction, to provide bedding systems customized for each person in order to provide spinal alignment for each person&#39;s particular size and body density. However, such mattresses with different firmness sections in the top supporting layer (the supporting layer closest to the body) provide an irregular firmness that tends to disturb persons in bed.  
      While substitutes for the Torbet mattress have been attempted, conventional mattresses having zones made from springs and foam do not have the same properties as the air zones in the Torbet mattress. In a Torbet mattress, the force distribution in a zone as a result of vertical depression (caused by a body part such as a shoulder) tends to be distributed and averaged laterally over the entire zone. Because air is fluid, air pressure in a Torbet mattress tends to be averaged and equally distributed in a zone. By way of distinction, the lateral and longitudinal distribution of forces due to a body part depression (for example, from a shoulder) into foam is more local, more complex and is a function of the displacement properties of the particular foam material used. Simple foam and spring mattresses in single or multiple layers have not provided the comfort and other benefits of the Torbet mattress.  
      The physical properties of mattress materials include among others Density, Hardness, Tensile Strength, Indentation Load Deflection, Compression Load Deflection, Initial Softness Ratio, Resilience (Elasticity), Compression Modulus, Hysteresis and Durability/Lifetime. These physical properties are described as follows.  
      Hardness is the resistance against pressure.  
      Density is the mass per unit volume. Hardness and density are interrelated. When density increases, hardness tends to increase. Generally for lower density materials, a growing loss in hardness arises after repeated loading.  
      Tensile Strength is the measure of the resistance against stretching and changes in tensile strength are measured as Tensile % and changes in length after applying a tensile force are measured as Elongation %.  
      Indentation Load Deflection (ILD) is a hardness measurement defined in the ISO 2439 standard. ILD in the standard is defined as the force that is required to compress material a percentage of its original thickness, that is, compressed 25%, 40% and 60% from its original thickness (using in the standard a circular plate of 322 cm 2 ). These ILD&#39;s are designated ILD 25% , ILD 40%  and ILD 60%    
      Compression Load Deflection (CLD) is a hardness measurement defined in the ISO 3386 standard. CLD is defined as the counter pressure (force per surface) in Pascal when the core material is pressed in 25% with a stamp where 1 kPA (kilopascal) equals 10 g/cm 2  (grams per square centimeter), Compression Set 75%.  
      Initial Softness Ratio (ISR) is a hardness measurement defined as the ratio of ILD 65% /ILD 5% . This measurement somewhat correlates to the initial perception of a person about the comfort of a mattress.  
      Resilience (Elasticity) is an elasticity measurement defined in the ASTM  3574  standard. Resilience/Elasticity is measured by the “ball-rebound” test where a steel ball is dropped from a height onto the mattress core and the rebound of the ball is measured as a % of a predetermined height.  
      Compression Modulus (Sag Factor) is a compression measurement defined in the ISO 2439 standard. This sag factor is defined as the ratio of ILD 65%  to ILD 25% . The sag factor somewhat correlates with the perception of a person as to whether the mattress supports the body with more uniform alignment.  
      Hysteresis is a measurement of the load deformation curve of the load surface. The hysteresis curve is determined by loading and de-loading of a mattress core. A circular plate of 355 mm diameter is used to gradually build a force up to a maximum of 1000 Newtons. The hysteresis represents the amount of energy that is absorbed by the material during loading/de-loading. The higher the absorption of energy by a mattress core, the more strength/energy is required by a person to change position on the mattress. Mattress cores which are too soft, have a low hysteresis which results in higher energy requirements for a person changing position on the mattress core. A low hysteresis value generally results in poor sleeping quality.  
      Durability/Lifetime is a measurement defined in one method by the EN 1957 standard. In this method, a weight of 1400 Newton is rolled 30,000 times up and down on the mattress core. Afterwards the height (Elevation), hardness, ILD and elasticity of the core are measured. This process is repeated once again and the results are compared with the original values and recorded as a as a % retention. The average incline of the hardness is determined at 210 N, 275 N and 340 N in the load deformation curve. Another measurement is defined by the ISO 3385 (DIN 5374) standard. In this method, a foam sample of 40×40 cm forced with a weight of 750 N for 80,000 times at 70 strokes per minute. Afterwards, the loss of height and the hardness are compared with the original values again as a % retention. Tear is another durability parameter measured in pounds per linear inch (pli) and indicates the energy required to pull a sample apart.  
      In addition to the technical parameters of ideal mattresses described above, many purchasers and merchants have come to expect beds to have other “standard properties”. For example, an expectation is that mattresses will have standard sizes such as King, Queen, Double and so forth with dimensions that match existing fitted-sheet sizes, frame sizes and other bedding equipment sizes. Further, an expectation is that a mattress will be compatible with a two-part bed formed of a foundation and a mattress which together are suitable for use with standard frames, such as “Hollywood” or “Harvard” frames. Purchasers and merchants expect that a bed when made-up with sheets and blankets will appear flat and uniform. The public expects that a bed will have the support and rigidity suitable for a person to sit on the edge for tying shoes or to sit on the edge for other purposes. While these “standard properties” generally do not add to the suitability of the bed for sleeping, they are nonetheless important for widespread commercial acceptance of mattresses.  
      A number of additional “attributes” are also important for commercial acceptance of mattresses. A mattress design desirably meets the needs of a large percentage of the population. The greatest demand is for beds that sleep two people side by side where typically, one of the two is larger than the other. Mattress sizes desirably accommodate a large percentage of pairs of people (for example, a large man and a smaller woman) in the population. A large percentage of the population is between the measurements for a 97.5 percentile male Caucasian and a 2.5 percentile female Caucasian. While other ethnic body types may be larger or otherwise different in measurement, most of the size differences for different body types are manifested in the length of legs so that, for purposes of mattress sizing, the ethnic size differences of people tend not to be significant. Mattresses are desirably available as a single integrated package easily installed as part of a bed without need for many separate or custom parts that require tailoring or otherwise increase the complexity of bed distribution and assembly. The number of stock keeping units (SKU&#39;s) required for a mattress product line is desirably low so that distribution and sale is efficient. Typically, mattresses are marketable in a family of three consumer prices ranges, namely high, medium and low and it is commercially desirable to have a mattress line that is marketable in those different price ranges.  
      Developments in the parameters of and manufacturing capabilities for foam and other materials have provided new components for mattresses that can be used to better approach the technical parameters required for an ideal mattress at economical costs and which can be manufactured with expected “standard properties” and with the “attributes” for mattresses that are desired by the public.  
      In consideration of the above background, there is a need for improved mattresses that better approach the properties of ideal mattresses and that can be economically manufactured while satisfying the public expectations and demands for mattresses.  
     SUMMARY  
      The present invention is a mattress for supporting a reclining body with low body pressure and in alignment. The mattress, extends in a lateral direction from side to side and extends in a longitudinal direction from a mattress head to a mattress foot where the mattress includes a head part, a shoulder part, a waist part, a hip part and a leg part. The reclining body has a displacement profile that causes the mattress to undergo differing vertical displacements when supporting the reclining body. The mattress core has displacement parameters established by internal contour interfaces varying to match the displacement profile of the reclining body while supporting the reclining body with low body pressure. The core has a plurality of regions where the vertical displacement in one or more of the regions varies to match the displacement profile of the reclining body to maintain the reclining body in alignment.  
      In certain preferred embodiments, the internal contour interfaces of foam members are manufactured using foam contour cutters that are programed with digital data in a database.  
      In an embodiment, the core includes a plurality of foam members arrayed in layers where the foam members at different positions exhibit different displacement parameters to support the reclining body with low body pressure and exhibit different vertical displacements to maintain the reclining body in alignment.  
      In an embodiment, the core includes a foam member having structural modification where the foam member at different longitudinal positions exhibits different displacement parameters to support the reclining body with low body pressure and exhibits different vertical displacements to maintain the reclining body in alignment.  
      In an embodiment, the core includes an adjustable lift for adjusting vertical displacement.  
      In an embodiment, the core includes one or more foam members and includes a tension relief slot for avoiding tension forces in the one or more foam members as a result of displacement caused by the reclining body.  
      In an embodiment where the core includes one or more foam members and one or more tension relief slots the core is within a cover that includes an opening on a top side of the mattress revealing the tension relief slot.  
      In an embodiment, the core includes one or more foam members and a spring supporting the foam members.  
      The foregoing and other objects, features and advantages of the invention will be apparent from the following detailed description in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  depicts an isometric view of a bed having a mattress with a top member supported by resilient support means having variable displacement parameters.  
       FIG. 2  depicts an isometric view of a mattress core used in one embodiment of the bed of  FIG. 1 .  
       FIG. 3  depicts a front view of a mattress core of  FIG. 2 .  
       FIG. 4  depicts a front view of further details of the mattress core of  FIG. 3 .  
       FIG. 5  depicts a front view of two top members, of the type employed in the mattress core of  FIG. 3 , mated in the manner manufactured using a contour cutter.  
       FIG. 6  depicts a front view of two bottom members, of the type employed in the mattress core of  FIG. 3 , mated in the manner manufactured using a contour cutter.  
       FIG. 7  depicts a side view of a 74 inch tall male body reclining on his side on a mattress core of the  FIG. 2  and  FIG. 3  type.  
       FIG. 8  depicts a side view of a 57 inch tall female body reclining on her side on a mattress core of the  FIG. 2  and  FIG. 3  type.  
       FIG. 9  depicts a top view of a 74 inch tall male body and a 57 inch tall female body reclining side-by-side on their backs on a mattress core of the  FIG. 2  and  FIG. 3  type.  
       FIG. 10  depicts a side view of a 74 inch tall male body reclining on his back on a mattress core of the  FIG. 2  and  FIG. 3  type.  
       FIG. 11  depicts a top view of a 74 inch tall male body and a 57 inch tall female body reclining side-by-side on their sides on a mattress core of the  FIG. 2  and  FIG. 3  type.  
       FIG. 12  depicts a side view of a 57 inch tall female body reclining on her back on a mattress core of the  FIG. 2  and  FIG. 3  type.  
       FIG. 13  depicts a side view of a mattress having a single top layer over two mating and variable thickness members designed for body alignment and low contact pressure of an average female.  
       FIG. 14  depicts a side view of the mattress of  FIG. 13  together with an average female reclining on her side.  
       FIG. 15  depicts a side view of a mattress having a single top layer over two mating and variable thickness members.  
       FIG. 16  depicts a side view of the mattress of  FIG. 15  together with an average male reclining on his side.  
       FIG. 17  depicts a front view of details of the an alternate embodiment of a mattress core similar to that of  FIG. 3 .  
       FIG. 18  depicts a front view of two top members, of the type employed in the mattress core of  FIG. 17 , mated in the manner manufactured using a contour cutter.  
       FIG. 19  depicts a front view of two bottom members, of the type employed in the mattress core of  FIG. 17 , mated in the manner manufactured using a contour cutter.  
       FIG. 20  depicts a side view of a 57 inch tall female body reclining on her side on a mattress core of the  FIG. 17  type.  
       FIG. 21  depicts a front view of an alternate bottom member, of the type employed in the mattress core of  FIG. 17 , where the contour cutting from the bottom.  
       FIG. 22  depicts a front view of an alternate bottom member, of the type employed in the mattress core of  FIG. 17 , where the contour cuts are of varying heights with generally uniform widths.  
       FIG. 23  depicts a front view of an alternate bottom member, of the type employed in the mattress core of  FIG. 17 , where the contour cuts are of varying widths with generally uniform heights.  
       FIG. 24  depicts a front view of an alternate bottom member, of the type employed in the mattress core of  FIG. 17 , where the contour cuts are of varying shapes with generally uniform heights.  
       FIG. 25  depicts a front view of details of the an alternate embodiment of a mattress core of  FIG. 17  measuring about 2134 mm in length (King Size-84 inches).  
       FIG. 26  depicts a front view of details of the an alternate embodiment of a mattress core of  FIG. 17  measuring about 1880 mm in length (Standard Size-74 inches).  
       FIG. 27  depicts a front view of details of the an alternate embodiment of a mattress core similar to that of  FIG. 3 .  
       FIG. 28  depicts a front view of two top members, of the type employed in the mattress core of  FIG. 27 , mated in the manner manufactured using a contour cutter.  
       FIG. 29  depicts a front view of two bottom members, of the type employed in the mattress core of  FIG. 27 , mated in the manner manufactured using a contour cutter.  
       FIG. 30  depicts an isometric view of a contour cutter cutting a foam bun into layers of the  FIGS. 5, 6 ,  28  or  29  type.  
       FIG. 31  depicts an isometric view of an alternate embodiment of a mattress core used in one embodiment of the bed of  FIG. 1 .  
       FIG. 32  depicts an isometric view of a bed, with a side-lying reclining body, and having the core of  FIG. 31 .  
       FIG. 33  depicts a three stage assembly process for the core of  FIG. 31 .  
    
    
     DETAILED DESCRIPTION  
       FIG. 1  depicts a front view of a bed  1  having a mattress  1   1  which is capable of supporting a reclining body (not shown) where the reclining body is supported by low body pressure and where the reclining body is maintained in alignment. The terminology low body pressure means a pressure which is below a pressure threshold (typically the ischemic threshold) for comfortable sleep and of a level which materially reduces causes of bed-induced shifting. The terminology maintained in alignment means an alignment from head to foot of a body that avoids or reduces lateral bending of the vertebral column of the body, particularly for a person in a side-sleeping position, and that eliminates or reduces sagging of the body.  
       FIG. 1  depicts an isometric view of a bed  1  having a mattress  1 , supported by a foundation  26  and a supporting frame  21 . The foundation  26  is a box spring, firm box, board or other conventional mattress support. The supporting frame  21  may be any frame and typically is a conventional “Hollywood” or “Harvard” style of bed frame that is made from right-angled channels and is supported by legs  6  having casters. The bed  1  and mattress  1 , extend in the longitudinal direction (X-axis direction) from a mattress head  5 - 1 ′ at bed head  5 - 1  to a mattress foot  5 - 2 ′ at bed foot  5 - 2 . The bed  1  and mattress  1   1  also extend in the lateral direction (Y-axis direction) normal to the X-axis and in the vertical direction (Z-axis direction) normal to the plane formed by the X-axis and the Y-axis.  
      The mattress  1   1  is for supporting a reclining person (see reclining persons in  FIG. 7  through  FIG. 16 , for example) where a person&#39;s reclining body includes a head part, a shoulder part, a waist part, a hip part and a leg part. The mattress  1   1  supports a reclining body positioned in the longitudinal direction with the head part toward the mattress head  5 - 1 ′ and the leg part toward the mattress foot  5 - 2 ′. A body reclining on mattress  1   1  depresses portions of the mattress causing the mattress to compress in the vertical direction (Z-axis direction) normal to the XY plane (formed by the X-axis and the Y-axis).  
      The mattress  1 , is formed of a core  2  formed, for example, of resilient members  22   1 ,  23   1  and  24   1  and has a top side  4 - 1  and a bottom side  4 - 2 . In the  FIG. 1  embodiment, the members  22   1 ,  23   1  and  24   1  are formed by one or more layers of foam having displacement parameters for providing a uniform supporting surface pressure to a reclining body. The term “displacement parameters” refers to any and all the properties and characteristics of materials that determine the static and dynamic tension and compression properties of a mattress. The mattress  1 , includes an outer cover  3  that encloses the inner members  22   1 ,  23   1  and  24   1 . The cover  3  typically includes a tape edge  16  formed around the outside top of the mattress  1   1 . Typically the top portion of the cover  2  includes a soft foam layer that is quilted with an ornamental design.  
      The resilient members  22   1 ,  23   1  and  24   1  are formed of materials that extend in the lateral direction (Y-axis direction) and that extend in the longitudinal direction (X-axis direction) to establish displacement parameters that vary in a least the vertical (Z-axis) direction as a function of the longitudinal position (X-axis position). The resilient members  22   1 ,  23   1  and  24   1  undergo different vertical compressions as a function of the longitudinal position (X-axis position) in order to follow the curvature of a reclining so as to establish alignment of the shoulder, waist and hip parts of a reclining body and so as to establish uniform low supporting surface pressure on the reclining body.  
      In the embodiment of  FIG. 1 , the resilient members  22   1 ,  23   1  and  24   1  have different displacement parameters that determine the compression that occurs in the mattress  1   1  in response to a reclining body. The resilient members  22   1 ,  23   1  and  24   1  have structural and displacement parameters that function to divide the mattress 1   1  into 1 ST , 2 ND  and 3 RD  regions. The 1 ST  region is established toward the head of the mattress  5 - 1 ′ and the 1 ST  region is for location beneath the head and shoulder parts of a reclining body. The 2 ND  region is established beneath the waist part of a body. The 3 RD  region is established toward the foot of the mattress  5 - 2 ′ and the 3 RD  region is for location beneath the hip and leg parts of a reclining body. The members  22   1 ,  23   1  and  24   1  have different displacement parameters that help establish the different compressions that occurs in each of the 1 ST , 2 ND  and 3 RD  regions, respectively, in order to achieve alignment of a reclining body with low supporting body pressure. The first and second foam members  22   1  and  23   1  have contour-cuts that mate to form a uniform interface between the members  22   1  and  23   1 .  
      The mattress  1   1  includes a cover  3  formed, on the top portion, by a stretch filling which in its uncompressed condition is typically about 1½ inches thick at the top side  4 - 1  of the mattress  1   1 . The cover  3  is about {fraction (1/16)} inch thick extending along the sides and along the bottom side  4 - 2  of the mattress  1   1 . The cover  3  functions to cover and contain the inner members of the mattress and the cover  3  has displacement parameters that provide a soft surface without interfering with the displacement parameters of the inner members of the mattress. The inner members of the mattress function when undergoing vertical compression to comfortably support a reclining body on top of the mattress  1   1 .  
       FIG. 2  depicts an isometric view of a mattress core  2  that is one embodiment of the core of the mattress  1   1  of  FIG. 1 . In the  FIG. 2  embodiment, the top member  22   1  has different thicknesses in the vertical direction (Z-axis direction) as a function of the longitudinal direction (X-axis direction). Also, the top member  22   1  has different slots  10 - 1 ,  10 - 2 ,  10 - 3  and  10 - 4  having heights in the vertical direction (Z-axis direction) and widths in the longitudinal direction (X-axis direction), extending entirely across the member  23   1  in the lateral direction (Y-axis direction) and locate at different positions in the longitudinal direction (X-axis direction). The core  2  also includes slots  11 - 1 ,  11 - 2 ,  11 - 3 ,  11 - 4 ,  12 - 1 ,  12 - 2 ,  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  in the member  23   1  of varying dimensions. Together, the variable thicknesses of the top member  22   1  and the varying dimensions and locations of the slots in the members  22   1  and  23   1  establish the variable “displacement parameters” in the core  2  in order to achieve alignment of a reclining body with low supporting body pressure.  
      The slots  11 - 1 ,  11 - 2 ,  11 - 3 ,  11 - 4 ,  12 - 1 ,  12 - 2 ,  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  extend entirely across the member  23   1  in the lateral direction (Y-axis direction), have varying widths in the longitudinal direction (X-axis direction) and have varying heights in the vertical direction (Z-axis direction) to establish displacement parameters that vary in a least the vertical direction (Z-axis direction) as a function of the longitudinal position (X-axis position) of core  22 . The members  22   1  and  23   1  undergo different vertical compressions to follow the curvature of a reclining body. Cooperatively, the slots  11 - 1 ,  11 - 2 ,  11 - 3 ,  11 - 4 ,  12 - 1 ,  12 - 2 ,  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  together with the remaining material in the members  22   1  establish varying displacement parameters for the core member  22   1 .  
       FIG. 3  depicts a front view of a mattress core of  FIG. 2 . In  FIG. 3 , the portions of the core in the region of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4 , in the region of the slots  12 - 1  and  12 - 2 , and in the region of slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  function to divide the core  2  in the longitudinal direction into different lateral-extending regions. The 1 ST  region is established by of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4  that are located beneath head and shoulder regions of a reclining body. The 2 ND  region is established by slots  12 - 1  and  12 - 2  that are located beneath the waist part of a reclining body. The 3 RD  region is established by the slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  that are located beneath the hip and leg parts of a reclining body.  
      When the core  2  of  FIG. 2  and  FIG. 3  is placed in the mattress  1   1  of  FIG. 1 , the resilient supporting Core members extend generally in the XY-plane (parallel to the page of the drawing) to establish different displacement parameters that determine vertical (Z-axis) mattress compression as a function of longitudinal (X-axis) position to achieve alignment of the head, shoulder, waist, hip and leg parts of a reclining body while maintaining low supporting body surface pressure.  
      In  FIG. 3 , the mattress core  2  is typical of a queen size and has overall dimensions of about 80 inches in the longitudinal (X-axis) direction and 60 inches in the lateral (Y-axis).  
       FIG. 4  depicts a front view of further details of the mattress core of  FIG. 3 . Dimensions of the mattress core  2  are in millimeters where the head is at the bottom of the page and the foot is at the top. The top member  22   1  mates with the bottom member  23   1 .  
       FIG. 5  depicts a front view of two top members  22   1 - 1  and  22   1 - 2  in an inverted mating arrangement in the position that they are manufactured using a foam contour cutter. The shaded member  22   1 - 1  is separated from the other member in  FIG. 5  and combined to form the mattress core  2  of  FIG. 4 .  
       FIG. 6  depicts a front view of two bottom members  23   1 - 1  and  23   1 - 2  in an inverted mating arrangement in the position that they are manufactured using a foam contour cutter. The shaded member  23   1 - 1  is separated from the other member in  FIG. 6  and combined to form the mattress core  2  of  FIG. 4 .  
       FIG. 7  depicts a side view of a 74 inch tall male body reclining on his side on a mattress core  2  of the  FIG. 2  and  FIG. 3  type. In  FIG. 7 , the portions of the core in the region of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4 , in the region of the slots  12 - 1  and  12 - 2 , and in the region of slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  function to divide the core  2  in the longitudinal direction into different lateral-extending regions which match those of the profile of a reclining body. The 1 ST  region is established by of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4  that support the head and shoulder regions of a reclining body  35  where the shoulder region has the greatest penetration. The 2 ND  region is established by slots  12 - 1  and  12 - 2  support the waist part of the reclining body  35  where the waist has less penetration than the shoulders and the hips. The 3 RD  region is established by the slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  support the hip and leg parts of the reclining body  35  where the hips have a grater penetration than the waist or leg regions.  
       FIG. 8  depicts a side view of a 57 inch tall female body reclining on her side on a mattress core  2  of the  FIG. 2  and  FIG. 3  type.  
       FIG. 8  depicts a front view of a mattress core  2  of  FIG. 2 . In  FIG. 8 , the portions of the core in the region of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4 , in the region of the slots  12 - 1  and  12 - 2 , and in the region of slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  function to divide the core  2  in the longitudinal direction into different lateral-extending regions. The 1 ST  region is established by of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4  support the head and shoulder regions of a reclining body  36 . The 2 ND  region is established by slots  12 - 1  and  12 - 2  support the waist part of the reclining body  36 . The 3 RD  region is established by the slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  support the hip and leg parts of the reclining body  36 .  
      When the core  2  of  FIG. 2  and  FIG. 8  is placed in the mattress  1   1  of  FIG. 1 , the resilient supporting core members extend generally in the XY-plane (parallel to the page of the drawing) to establish different displacement parameters that determine vertical (Z-axis) mattress compression as a function of longitudinal (X-axis) position to achieve alignment of the head, shoulder, waist, hip and leg parts of a reclining body while maintaining low supporting body surface pressure.  
      In  FIG. 8 , the mattress core  2  is typical of a queen size and has overall dimensions of about 80 inches in the longitudinal (X-axis) direction and 60 inches in the lateral (Y-axis).  
       FIG. 9  depicts a top view of a 74 inch tall male body  35  and a 57 inch tall female body  36  reclining side-by-side on their backs on a mattress core  2  of the  FIG. 2  and  FIG. 3  type. In  FIG. 9 , the portions of the core  2  in the region of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4 , in the region of the slots  12 - 1  and  12 - 2 , and in the region of slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  function to divide the core  2  in the longitudinal direction into different lateral-extending regions. The 1 ST  region is established by of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4  that support the head and shoulder regions of a reclining bodies  35  and  36 . The 2 ND  region is established by slots  12 - 1  and  12 - 2  support the waist part of bodies  35  and  36 . The 3 RD  region is established by the slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  support the hip and leg parts of the bodies  35  and  36 .  
       FIG. 10  depicts a side view of a 74 inch tall male body reclining on his back on a mattress core of the  FIG. 2  and  FIG. 3  type.  
       FIG. 11  depicts a top view of a 74 inch tall male body and a 57 inch tall female body reclining side-by-side on their sides on a mattress core of the  FIG. 2  and  FIG. 3  type. In  FIG. 11 , the portions of the core  2  in the region of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4 , in the region of the slots  12 - 1  and  12 - 2 , and in the region of slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  function to divide the core  2  in the longitudinal direction into different lateral-extending regions. The 1 ST  region is established by of the slots  11 - 1 ,  11 - 2 ,  11 - 3  and  11 - 4  that support the head and shoulder regions of a reclining bodies  35  and  36 . The 2 ND  region is established by slots  12 - 1  and  12 - 2  support the waist part of bodies  35  and  36 . The 3 RD  region is established by the slots  13 - 1 ,  13 - 2 ,  13 - 3 , and  13 - 4  support the hip and leg parts of the bodies  35  and  36 .  
       FIG. 12  depicts a side view of a 57 inch tall female body reclining on her back on a mattress core of the  FIG. 2  and  FIG. 3  type.  
       FIG. 13  depicts a side view of a core  2   13  having a uniform resilient top member  50 - 1  over a resilient supporting means  23   13  formed of two mating and variable thickness members  50 - 2  and  50 - 3 . The core  2   13  has a uniformly flat top surface  4 - 1  and a uniformly flat bottom surface  4 - 2 . The core  2   13  is designed for body alignment and low contact pressure of a typical female body.  
      In  FIG. 13 , the core  2   13  is typically supported by a conventional foundation, such as foundation  26  in  FIG. 1 , on bottom surface  4 - 2 . In the  FIG. 13  embodiment, the resilient top member  50 - 1  constitutes a uniform top region below the top surface  4 - 1  for supporting and distributing the weight of a reclining body in cooperation with resilient supporting means  23   13 . The top member  50 - 1  is formed, for example, by one or more layers of foam having uniform displacement parameters for providing a uniform supporting surface pressure to a reclining body. In one embodiment, the members  50 - 1 ,  50 - 2  and  50 - 3  have ILD&#39;s of 15R, 6R and 28HR, respectively, so that the members  50 - 1 ,  50 - 2  and  50 - 3  are medium, soft and firm, respectively.  
      In  FIG. 13 , the core  2   13  is formed of multiple members that extend in the XY-plane (a plane normal to the page of the drawing) to establish different displacement parameters that help determine the core compression in the longitudinal direction for alignment of the head, shoulder, waist, hip and leg parts of a reclining body at low supporting body surface pressure.  
      In one embodiment, the resilient top member  50 - 1  and the resilient supporting means  23   3  have a lateral slot  15 ′″ that extends through top member  50 - 1  from the top surface  4 - 1  to and partially through the resilient supporting means  23   3  to the top of bottom member  50 - 3 . The slot  15 ′″ extends laterally across (in a direction normal to the page in FIG.) the core  2   13 . The slot  15 ′″ functions to relieve tension forces that would otherwise be created by shoulder depression into members  50 - 1  and  50 - 2  of the core  2   13 .  
      In  FIG. 13 , the members  50 - 2  and  50 - 3  with irregular internal surfaces are manufactured, for example, by contour cutting regular constant thickness foam members. Techniques for contour cutting of foam are well known.  
       FIG. 14  depicts a side view of the mattress of  FIG. 13  together with a female body  36  reclining on her side.  
      In  FIG. 14 , the resilient top member  50 - 1  has a top surface  4 - 1  that has been depressed by the body  36  so that it follows the curvature of the body. The top member  50 - 1  is in contact with the body (through a cover like cover  3  in  FIG. 3 ) and functions to support and distribute the weight of the body in cooperation with resilient supporting means  23   13 . The top member  50 - 1  is formed, for example, by one layer of constant thickness foam having uniform displacement parameters for providing a uniform supporting surface pressure to the reclining body  36 . A pillow  20  is positioned under the head of body  36 .  
      In the 1 ST  region, the head section includes the foam members  50 - 1 ,  50 - 2  and  50 - 3  for supporting the head part of reclining body  36  where the firmer member  50 - 3  is the thickest and members  50 - 1  and  50 - 2  are about the same thickness in the uncompressed state (see  FIG. 13 ). The foam members  50 - 1 ,  50 - 2  and  50 - 3  undergo only a small compression in the head section and provide appropriate displacement parameters for the head part of the side-lying female body  36 . The shoulder section includes the foam members  50 - 1 ,  50 - 2  and  50 - 3  where in the uncompressed state (see  FIG. 13 ) the softer member  50 - 2  is the thickest. The foam members  50 - 1 ,  50 - 2  and  50 - 3  are substantially compressed by the shoulder of the reclining body  36 . Together, in the shoulder region, the foam members  50 - 1 ,  50 - 2  and  50 - 3  provide appropriate displacement parameters for the shoulder part of the side-lying female body  36 .  
      In the 2 ND  region, the waist section includes the foam members  50 - 1 ,  50 - 2  and  50 - 3  for supporting the waist part of reclining body  36  where the softer member  50 - 2  is the thinnest and where the firmer member  50 - 3  is the thickest. Together, in the waist region, the foam members  50 - 1 ,  50 - 2  and  50 - 3  provide appropriate displacement parameters for the waist part of the side-lying female body  36 .  
      In the 3 RD  region, the hip section includes foam members  50 - 1 ,  50 - 2  and  50 - 3  for supporting the hip part of the reclining body  36  where, in the uncompressed state (see  FIG. 13 ), the firmer member  50 - 3  is the thickest and members  50 - 1  and  50 - 2  are about the same thickness. Together, in the hip section, foam members  50 - 1 ,  50 - 2  and  50 - 3  provide appropriate displacement parameters for the hip part of the side-lying female body  36 . In the leg section, foam members  50 - 1 ,  50 - 2  and  50 - 3  are for supporting the leg part of the reclining body  36  where, in the uncompressed state (see  FIG. 13 ), the firmer member  50 - 3  is the thickest and members  50 - 1  and  50 - 2  are about the same thickness. Together, in the leg section, foam members  50 - 1 ,  50 - 2  and  50 - 3  provide appropriate displacement parameters for the leg part of the side-lying female body  36 .  
      In  FIG. 14 , the shoulders have an alignment line  17   14 - 1 , the waist has an alignment line  17   14 - 2 , the hips have an alignment line  17   14 - 3 , the legs have an alignment line  17   14 - 4  and the spine has an alignment line  18   14 . In  FIG. 14 , the waist of the body is straight so the spine alignment line  18   14  is straight. The surface pressures T 1 , T 2 , T 3  and T 4  at the shoulder alignment line  17   14 - 1 , the waist alignment line  17   14 - 2 , the hip alignment line  17   14 - 3  and the leg alignment line  17   14 - 4  are typically low and below a low pressure threshold. For a bed made of properly selected foams and other materials, the low pressure threshold is below the ischemic pressure of about 30 mmHg.  
       FIG. 15  depicts a side view of a mattress core  2  having a single top layer over two mating and variable thickness members. The core  2   15  has a uniform resilient top member  81 - 1  over a resilient supporting means  23   15  formed of two mating and variable thickness members  81 - 2  and  81 - 3 . The core  2   15  has a uniformly flat top surface  4 - 1  and a uniformly flat bottom surface  4 - 2 . The core  2   15  is designed for body alignment and low contact pressure of typical male body.  
      In  FIG. 15 , the core  2   15  is typically supported by a conventional foundation, like foundation  26  in  FIG. 1 , on bottom surface  4 - 2 . In the  FIG. 15  embodiment, the resilient top member  81 - 1  constitutes a uniform top region below the top surface  4 - 1  for supporting and distributing the weight of a reclining body in cooperation with resilient supporting means  23   15 . The top member  81 - 1  is formed, for example, by one or more layers of foam having uniform displacement parameters for providing a uniform supporting surface pressure to a reclining body. In one embodiment, the members  81 - 1 ,  81 - 2  and  81 - 3  have ILD&#39;s of 13R, 15R and 28HR, respectively, so that the members  81 - 1 ,  81 - 2  and  81 - 3  are firm, soft and firm, respectively.  
      In  FIG. 15 , the core  2   15  is formed of multiple members that extend in the XY-plane (a plane normal to the page of the drawing) to establish different displacement parameters that help determine the core compression in the longitudinal direction for alignment of the head, shoulder, waist, hip and leg parts of a reclining body at low supporting body surface pressure.  
      In one embodiment, the top member  81 - 1  and the resilient supporting means  23   15  have a lateral slot  15 ′″ that extends through top member  81 - 1  from the top surface  4 - 1  to and partially through the resilient supporting means  23   15  to the top of a bottom member  81 - 3 . The slot  15 ′″ extends laterally across (in a direction normal to the page in  FIG. 15 ) the core  2   15 . The slot  15 ′″ functions to relieve tension forces in members  81 - 1  and  81 - 2  that would otherwise be created by shoulder depression into the core  2   15 .  
       FIG. 16  depicts a side view of the mattress core  2   15  of  FIG. 15  together with an average male  35  reclining on his side. The mattress core  2   15  includes a resilient top member  81 - 1  that has a top surface  4 - 1  that has been depressed by the body  35  so that it follows the curvature of the body. The top member  81 - 1  is in contact with the body (through a cover material not shown like cover material  3  in  FIG. 1 ) and functions to support and distribute the weight of the body in cooperation with resilient supporting means  23   15 . The top member  81 - 1  is formed, for example, by one layer of constant thickness foam having uniform displacement parameters for providing a uniform supporting surface pressure to the reclining body  35 . A pillow  20  is positioned under the head of body  35 .  
      In a 1 ST  region of core  2   15 , the head section includes the foam members  81 - 1 ,  81 - 2  and  81 - 3  for supporting the head part of reclining body  35  where, in the uncompressed state (see  FIG. 15 ), the firmer member  81 - 3  is the thickest and members  81 - 1  and  81 - 2  are about the same thickness. The foam members  81 - 1 ,  81 - 2  and  81 - 3  undergo only a small compression and provide appropriate displacement parameters for the head part of the side-lying male body  35 . The shoulder section includes the foam members  81 - 1 ,  81 - 2  and  81 - 3  where, in the uncompressed state (see  FIG. 15 ), the softer member  81 - 2  is the thickest. The foam members  81 - 1 ,  81 - 2  and  81 - 3  are substantially compressed by the shoulder of the reclining body  35 . Together, in the shoulder region, the foam members  81 - 1 ,  81 - 2  and  81 - 3  provide appropriate displacement parameters for the shoulder part of the side-lying male body  35 .  
      In a 2 ND  region of core  215 , the waist section includes the foam members  81 - 1 ,  81 - 2  and  81 - 3  for supporting the waist part of reclining body  35  where the softer member  81 - 2  is the thinnest and where, in the uncompressed state (see  FIG. 15 ), the firmer member  81 - 3  is the thickest. Together, in the waist region, the foam members  81 - 1 ,  81 - 2  and  81 - 3  provide appropriate displacement parameters for the waist part of the side-lying male body  35 .  
      In a 3 RD  region of core  2   15 , the hip section includes foam members  81 - 1 ,  81 - 2  and  81 - 3  for supporting the hip part of the reclining body  35  where, in the uncompressed state (see  FIG. 15 ), the firmer member  81 - 3  is the thickest and members  81 - 1  and  81 - 2  are about the same thickness. Together, in the hip section, foam members  81 - 1 ,  81 - 2  and  81 - 3  provide appropriate displacement parameters for the hip part of the side-lying male body  35 . In the leg section, foam members  81 - 1 ,  81 - 2  and  81 - 3  are for supporting the leg part of the reclining body  35  where, in the uncompressed state (see  FIG. 15 ), the firmer member  81 - 3  is the thickest and members  81 - 1  and  81 - 2  are about the same thickness. Together, in the leg section, foam members  81 - 1 ,  81 - 2  and  81 - 3  provide appropriate displacement parameters for the leg part of the side-lying male body  35 .  
      In  FIG. 16 , the shoulders have an alignment line  17   27 - 1 , the waist has an alignment line  17   27 - 2 , the hips have an alignment line  17   27 - 3 , the legs have an alignment line  17   27 - 4  and the spine has an alignment line  18   27 . In  FIG. 16 , the waist of the body is straight so the spine alignment line  18   27  is straight. The surface pressures between the body and the core at the shoulder alignment line  17   27 - 1  the waist alignment line  17   27 - 2 , the hip alignment line  17   27 - 3  and the leg alignment line  17   27 - 4  are typically low and below a low pressure threshold. For a bed made of properly selected foams and other materials, the low pressure threshold is below the ischemic pressure of about 30 mmHg.  
       FIG. 17  depicts a front view of details of the an alternate embodiment of a mattress core  2   17  similar to the mattress core  2  that of  FIG. 4 . Dimensions of the mattress core  2   17  are in millimeters where the head is at the bottom of the page and the foot is at the top. The top member  22   17  mates with the bottom member  23   17 .  
       FIG. 18  depicts a front view of two top members  22   17 - 1  and  22   17 - 2  of a mattress core  2   17  in an inverted mating arrangement in the position that they are manufactured using a foam contour cutter. The shaded member  22   17 - 1  is separated from the other member  22   17 - 2  in  FIG. 18  and combined to form the mattress core  2   17  of  FIG. 17 .  
       FIG. 19  depicts a front view of two bottom members  23   17 - 1  and  23   17 - 2  of a mattress core  2   17  in an inverted mating arrangement in the position that they are manufactured using a foam contour cutter. The shaded member  23   17 - 1  is separated from the other member  23   17 - 2  in  FIG. 18  and combined to form the mattress core  2   17  of  FIG. 17 .  
       FIG. 20  depicts a side view of a 57 inch tall female body reclining on her side on a mattress core  2   20  having members  22   20 ,  23   20  and  24   20  similar to the members  22   17 ,  23   17  and  24   17  of  FIG. 17 .  
       FIG. 21  depicts a front view of an alternate bottom member  232 , of the type employed in the mattress core of  FIG. 17  where the cuts to form the slots  44   1 ,  44   2 ,  44   3 , . . . ,  44   10 ,  44   11 , are made from the bottom side  4 - 2 . The slots  44   1 ,  44   2 ,  44   3 , . . . ,  44   10 ,  44   11 , have variable height and width to determine the displacement parameters of the core.  
       FIG. 22  depicts a front view of an alternate bottom member  23   22  of the type employed in the mattress core of  FIG. 17  where the cuts to form the slots  45   1 ,  45   2 ,  45   3 , . . . ,  45   15 ,  45   16  are made from the bottom side  4 - 2 . The slots  45   1 ,  45   2 ,  45   3 , . . . ,  45   15 ,  45   16  have variable heights with generally uniform widths and are designed with height and spacing to match the displacement profile of the core to the profile of a reclining body.  
       FIG. 23  depicts a front view of an alternate bottom member  23   23  of the type employed in the mattress core of  FIG. 17  where the cuts to form the slots  46   1 ,  46   2 ,  46   3 , . . . ,  46   21 ,  46   22  are made from the bottom side  4 - 2 . The slots  46   1 ,  46   2 ,  46   3 , . . . ,  46   21 ,  46   22  have generally uniform heights and are designed with variable widths and spacing to match the displacement profile of the core to the profile of a reclining body.  
       FIG. 24  depicts a front view of an alternate bottom member  23   24  of the type employed in the mattress core of  FIG. 17  where the cuts to form the slots  47   1 ,  47   2 ,  47   3 , . . . ,  47   21 ,  47   22  are made from the bottom side  4 - 2 . The slots  47   1 ,  47   2 ,  47   3 , . . . ,  47   21 ,  47   22  have generally uniform heights and are designed with variable shapes and spacing to match the displacement profile of the core to the profile of a reclining body.  
       FIG. 25  depicts a front view of details of the an alternate embodiment of a mattress core of  FIG. 17  measuring about 2134 mm in length (King Size-84 inches).  
       FIG. 26  depicts a front view of details of the an alternate embodiment of a mattress core of  FIG. 17  measuring about 1880 mm in length (Standard Size-74 inches).  
       FIG. 27  depicts a front view of details of the an alternate embodiment of a mattress core  2   27  similar to that of  FIG. 3 .  
       FIG. 28  depicts a front view of two top members  22   27 - 1  and  22   27 - 2 , of the type employed in the mattress core of  FIG. 27 , mated in the manner manufactured using a contour cutter.  
       FIG. 29  depicts a front view of two bottom members  23   27 - 1  and  23   27 - 2 , of the type employed in the mattress core of  FIG. 27 , mated in the manner manufactured using a contour cutter.  
       FIG. 30  depicts an isometric view of a contour cutter used for cutting a foam bun into layers of the  FIGS. 5 and 6 ,  FIGS. 18 and 19  or  FIG. 28  or  29  type. In  FIG. 30 , the foam contour cutter  53  includes a base  56  including a left translation track  56   L  and a right translation track  56   R  for cutting movement in the X-axis direction. The left translation track  56   L  and right translation track  56   R  support a blade guide  57  that houses a blade  55 . The blade guide  57  moves the blade  55  in the Z-axis direction. The blade  55  is moved at high speed around the blade guide  57  and passes through and cuts the foam bun  50 . The blade  55  is digital commanded to move back and forth by translation of the blade  55  and blade guide  57  in the X-axis direction and to translate up and down in the Z-axis direction. The digital commands are stored in the contour database  51  and in response to the stored commands, the contour controller  52  controls the contour cutter to cut the foam bun. In a preferred embodiment, the bun  50  is cut in nested pairs. In the example of  FIG. 30 , six pairs  50 - 1 ,  50 - 2 , . . . ,  50 - 6  of mattress members are shown. The pairs  50 - 1 ,  50 - 2 , . . . ,  50 - 6  are, for example, the top member pairs as showns in  FIGS. 5, 18  or  28  or the bottom member pairs as shown in  FIGS. 6, 19  or  29 . By cutting the members in nested pairs, the amount of waste foam from the bun  50  is reduced or minimized.  
      The code listing stored in the Contour Database  51  of  FIG. 30  for cutting the base members  23   27 - 1  and  23   27 - 2  of  FIG. 28  are shown in the following TABLE 1.  
                                   TABLE 1                                   Member 23 27 -1       Member 23 27 -2                                                                    0   0       1860   180           0   180       1860   325           160   180       1821   325           160   35       1821   180           199   35       1716   180           199   180       1716   335           304   180       1677   335           304   25       1677   180           343   25       1572   180           343   180       1572   335           448   180       1533   335           448   25       1533   180           487   25       1428   180           487   180       1428   303           592   180       1390   303           592   57       1390   180           630   57       1343   180           630   180       1343   230           677   180       1338   230           677   130       1338   180           682   130       1295   180           682   180       1295   300           725   180       1290   300           725   60       1290   180           730   60       1240   165           730   180   0   1190   180           780   195   0   1190   325           830   180       1180   325           830   35       1180   180           840   35       1080   180           840   180       1080   335           940   180       1070   335           940   25       1070   180           950   25       970   180           950   180       970   335           1050   180       960   335           1050   25       960   180           1060   25       860   180           1060   180       860   325           1160   180       850   325           1160   35       850   180           1170   35       830   180           1170   180       780   195           1190   180   0   750   190           1240   165   0   750   303           1270   170       740   303           1270   57       740   186           1280   57       730   180           1280   174   0   0   180           1290   180   0   0   360           2020   180       2020   360                       2020   0                       0   0                      
 
       FIG. 31  depicts an isometric view of an alternate embodiment of a mattress core  2   31  used in embodiment of the bed of  FIG. 1 . The core  23 , includes a top member  223 , which is typically 2 or three inches thick and typically is 3 or 5 pound Visco elastic or similar Resilitex™ foam. The bottom layer is continuous wave members  23 - 1   31 ,  23 - 2   31  and  23 - 3   31 . Members  23 - 1   31 ,  23 - 2   31  and  23 - 3   31  typically are Reflex or HR foam. In one embodiment, members  23 - 1   31  and  23 - 3   31  have ILDs or 40 and member  23 - 3   31  has an ILD of 21.  
       FIG. 32  depicts an isometric view of a bed  1   32 , with a side-lying reclining body, and having the core  2   31  of  FIG. 31  type. 1.The core  2   31  includes the top member  22   31  and the bottom layer formed of continuous wave members  23 - 1   31 ,  23 - 2   31  and  23 - 3   31 . The member  23 - 3   31  can be a single piece or two pieces as shown in  FIG. 33 . The first and second foam members  23 - 1   31  and  23 - 2   31  have continuous wave contour-cuts that mate to form a uniform interface between the members  23 - 1   31  and  23 - 2   31 .  
       FIG. 33  depicts a three stage assembly process for the core  2   31  of  FIG. 31 . Typically, the continuous wave members  23 - 1   31 ,  23 - 2   31  and  23 - 3   31  are manufactured separately with a contour cutter as shown and described in connection with  FIG. 30 .  
      The code listing stored in the Contour Database  51  of  FIG. 30  for cutting the base members  23 - 2   31  and  23 - 1   31  of core  23 , are shown in the following TABLE 2.  
                   TABLE 2                          Member 23-2 31     Member 23-1 31                               X-axis   Y-axis   X-axis   Y-axis                                                             mm   inch       mm   inch       mm   inch       mm   inch                                                                         0   0       0   0       0   0       0   0           0   0       179   7.047       0   0       179   7.047       133   5.236       179   7.047       33   1.299       179   7.047       135   5.315       120   4.724   0   35   1.378       120   4.724   0       160   6.299       65   2.559   0   60   2.362       65   2.559   0       220   8.661       40   1.575   0   120   4.724       40   1.575   0       320   12.598       43   1.693   0   220   8.661       43   1.693   0       420   16.535       57   2.244   0   320   12.598       57   2.244   0       480   18.898       75   2.953   0   380   14.961       75   2.953   0       530   20.866       95   3.74   0   430   16.929       95   3.74   0       570   22.441       110   4.331   0   470   18.504       110   4.331   0       600   23.622       118   4.646       530   20.866       124   4.882       600   23.622       60   2.362       540   21.26       125   4.921   0       610   24.016       60   2.362       600   23.622       128   5.039   0       610   24.016       120   4.724   0   680   26.772       130   5.118   0       630   24.803       124   4.882   0   720   28.346       120   4.724   0       700   27.559       128   5.039   0   750   29.528       89.5   3.524   0       740   29.134       129   5.079       780   30.709       59   2.323   0       740   29.134       60   2.362       820   32.283       49   1.929   0       750   29.528       60   2.362       900   35.433       51   2.008       750   29.528       129   5.079   0   920   36.22       51.5   2.028   0       780   30.709       130   5.118   0   970   38.189       55   2.165   0       820   32.283       120   4.724   0   1030   40.551       69   2.717   0       850   33.465       89.5   3.524   0   1070   42.126       84   3.307   0       880   34.646       59   2.323   0   1120   44.094       104   4.094   0       920   36.22       49   1.929   0   1180   46.457       122   4.803   0       950   37.402       50   1.969       1280   50.394       136   5.354   0       950   37.402       119   4.685       1380   54.331       139   5.472   0       960   37.795       119   4.685       1440   56.693       114   4.488   0       960   37.795       50   1.969   0   1465   57.677       59   2.323       1000   39.37       51   2.008   0   1467   57.756       0   0       1070   42.126       55   2.165   0   1500   59.055       0   0       1090   42.913       59   2.323       1500   59.055       179   7.047       1090   42.913       119   4.685       1380   54.331       179   7.047       1100   43.307       119   4.685       1380   54.331       139   5.472       1100   43.307       61   2.402   0   1380   54.331       179   7.047       1130   44.488       69   2.717   0   340   13.386       179   7.047       1170   46.063       84   3.307   0   340   13.386       90   3.543       1220   48.031       104   4.094   0   330   12.992       90   3.543       1280   50.394       122   4.803   0   330   12.992       179   7.047       1380   54.331       136   5.354   0   210   8.268       179   7.047       1480   58.268       139   5.472       210   8.268       70   2.756       1480   58.268       0   0       200   7.874       70   2.756       1480   58.268       139   5.472   0   200   7.874       179   7.047       1540   60.63       114   4.488   0   90   3.543       179   7.047       1565   61.614       59   2.323       90   3.543       80   3.15       1567   61.693       0   0       80   3.15       80   3.15       1700   66.929       0   0       80   3.15       179   7.047       1700   66.929       179   7.047       0   0       179   7.047       0   0       179   7.047       780   30.709       179   7.047       220   8.661       179   7.047       780   30.709       89   3.504       220   8.661       40   1.575       790   31.102       89   3.504       220   8.661       179   7.047       790   31.102       179   7.047       1700   66.929       179   7.047       960   37.795       179   7.047       1700   66.929       0   0       960   37.795       89   3.504       0   0   T   0   0       970   38.189       89   3.504                               970   38.189       179   7.047                               1500   59.055       179   7.047                               1500   59.055       0   0                               1420   55.905       0   0                               1420   55.905       99   3.898                               1410   55.512       99   3.898                               1410   55.512       0   0                               1300   51.181       0   0                               1300   51.181       109   4.291                               1290   50.787       109   4.291                               1290   50.787       0   0                               1170   46.063       0   0                               1170   46.063       89   3.504                               1160   45.669       89   3.504                               1160   45.669       0   0                               720   28.346       0   0                               720   28.346       90   3.543                               710   27.953       90   3.543                               710   27.953       0   0                               540   21.26       0   0                               540   21.26       90   3.543                               530   20.866       90   3.543                               530   20.866       0   0                               120   4.724       0   0                               120   4.724       40   1.575                               120   4.724       0   0                               0   0   T   0   0   T                  
 
      While the invention has been particularly shown and described with reference to preferred embodiments thereof it will be understood by those skilled in the art that various changes in form and details amy be made therein without departing from the scope of the invention.