According to the present invention, in a plan view of a seat surface (10a), a plane area of a part surrounded by an inner edge (17a) of a rear part (17) in a left-right direction (X) and a contour (L) is larger than a plane area of a part sandwiched by an inner edge (18a) of a front part (18) in the left-right direction (X) and the contour (L) in the left-right direction (X). In addition, a part of a pair of left and right second synthetic resin materials forming a lower part having a maximum gap therebetween in the left-right direction (X) is positioned in a thigh rest part (14) and a part having a minimum gap is positioned in a hip rest part (15), and a maximum value (W1) of the gap between the pair of left and right second synthetic resin materials forming the lower part in the left-right direction (X) is two times or more a minimum value (W2) of the gap in the left-right direction (X).

A system for evaluating failure of a used mattress includes a test device and computerized test device control module. The test device includes a plunger arm, a control motor attached to a first end of the plunger arm and configured to selectively extend and retract the plunger arm, and a platen attached to an end of the plunger arm distal from control motor. The control module includes a computerized processor, operating programming to evaluate the failure of the mattress. The programming includes controlling extension of the plunger arm, monitoring firmness in the mattress based upon force applied by the platen on the mattress and displacement of the plunger arm, monitoring a threshold firmness value for comparison, comparing the threshold firmness value to the monitored firmness, and generating a result of the comparison indicating the failure of the mattress.

A symmetrical zoned foam mattress includes an upper foam layer with a wavy lower side and a lower foam layer with a wavy upper side. The lower layer has top, middle and bottom lateral valleys. The wavy lower side of the upper layer is glued to the wavy upper side of the lower layer. The top lateral valley has a minimum located within eighteen inches of the top head end of the lower layer. The bottom lateral valley has a minimum located within eighteen inches of the bottom foot end of the lower layer. A center plane intersects the lower foam layer at a minimum of the middle lateral valley. The minimum of each of the top and bottom lateral valleys is about fifteen inches from the end of the mattress regardless of whether the consumer chooses to use the top or bottom end as the head of the mattress.

Systems, methods, and apparatus are provided for preventing and treating pressure ulcers in bedfast patients. The invention includes providing a non-powered mattress having a first zone adapted to conform to a first body part and a second zone adapted to provide support to a second body part, and off-loading interface pressure on the first body part to the second body part by dynamically increasing the support provided to the second body part by the second zone based on a weight of the first body part on the first zone. The off-loading of interface pressure from the first body part to the second body part equalizes blood oxygen saturation in tissue of the first and second body parts. Numerous additional aspects are disclosed.

A flexible polyurethane foam molded article includes a plurality of layer parts (L1 to L10) that are layered in a vertical direction (Y) perpendicular to a stage surface (1A). When the entire flexible polyurethane foam molded article is compressed by 15% in the vertical direction (Y), the front surface layer (L1) positioned closest to the stage surface (1A) in the vertical direction (Y) among the plurality of layer parts (L1 to L10) has the lowest residual thickness ratio in the vertical direction (Y) among the plurality of layer parts (L1 to L10). When the entire flexible polyurethane foam molded article is compressed by 50% in the vertical direction (Y), the back surface layer (L10) positioned closest to a non-stage surface (1B) of the flexible polyurethane foam molded article in the vertical direction (Y) among the plurality of layer parts (L1 to L10) has the highest residual thickness ratio in the vertical direction (Y) among the plurality of layer parts (L1 to L10).

A multi-zone mattress comprising a top layer, an intermediate layer and a bottom layer disposed in substantially parallel relationship relative to each other including a first plurality of zones each having a first firmness profile to support a person thereon separated by a second plurality of zones each having a second firmness profile less than the firmness of the first firmness profile of the first plurality of zones, the first plurality of zones and the second plurality of zones each cooperatively formed by corresponding sections of the top layer, intermediate layer and bottom layer disposed in substantially parallel alignment relative to each other.

A foam core mattress including a cushion layer having a foam with an IFD of between about 6 to about 18 and a density of between about 1.5 lb./ft.sup.3 to about 4 lb./ft.sup.3. The mattress includes a core that is coupled with a bottom surface of the cushion layer. The core includes a matrix of rebond foam pieces that includes at least 5% foam pieces having volumes of less than about 0.5 in.sup.3, at least 40% foam pieces having volumes of between about 0.5 and 2.0 in.sup.3, and at least 20% foam pieces having volumes of greater than 2.0 in.sup.3, wherein the core has an IFD of between about 21 and 36. The mattress includes a base layer coupled with a bottom surface of the core. The base layer has an IFD of between about 28 to about 70 and a density of between 1.5 lb./ft.sup.3to about 2 lb./ft.sup.3.

A mattress is disclosed, comprising two layersa first layer and a second layereach layer comprising a top surface and a bottom surface that are distinct in firmness, feel, and/or other parameters relevant to sleeping. The first layer and the second layer are stacked on top of each other and may easily be flipped and re-stacked by a user in the home.

A mattress embodying a removable exterior top and interchangeable segments (e.g. foam) positioned above a mattress base support portion and below the removable exterior top. The removable exterior top may be replaced with new or different removable exterior tops. Also, users have the ability to vary softness (i.e., firmness) or other characteristics (e.g., foam component construct) across the mattress by arranging or rearranging the interchangeable segments located directly below the removable and interchangeable mattress top. An exemplary base support portion may include a heavy duty pocketed inner-coil unit for motion transfer support and increased airflow.

Embodiments of a ventilated sleep system and an airflow/breathable mattress foundation are disclosed, and typically may be configured to provide ventilation to a mattress, for example through an upper surface of a foundation allowing airflow therethrough. Typically, sleep system embodiments may include mattresses with foam layers with ventilation passageways in fluid communication with a lower surface of the mattress cover, which is configured to allow airflow therethrough, and some embodiments may also include foam pillars. Such sleep system embodiments typically may have such a ventilation mattress atop such a ventilation foundation, with airflow therebetween.